https://openjdk.java.net/ 
/*
 * Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.awt;

import java.applet.Applet;
import java.awt.dnd.DropTarget;
import java.awt.event.ActionEvent;
import java.awt.event.AdjustmentEvent;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.HierarchyBoundsListener;
import java.awt.event.HierarchyEvent;
import java.awt.event.HierarchyListener;
import java.awt.event.InputEvent;
import java.awt.event.InputMethodEvent;
import java.awt.event.InputMethodListener;
import java.awt.event.ItemEvent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.event.PaintEvent;
import java.awt.event.TextEvent;
import java.awt.im.InputContext;
import java.awt.im.InputMethodRequests;
import java.awt.image.BufferStrategy;
import java.awt.image.ColorModel;
import java.awt.image.ImageObserver;
import java.awt.image.ImageProducer;
import java.awt.image.VolatileImage;
import java.awt.peer.ComponentPeer;
import java.awt.peer.ContainerPeer;
import java.awt.peer.LightweightPeer;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.beans.Transient;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.Serializable;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.util.Collections;
import java.util.EventListener;
import java.util.HashSet;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.Vector;

import javax.accessibility.Accessible;
import javax.accessibility.AccessibleComponent;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;
import javax.accessibility.AccessibleSelection;
import javax.accessibility.AccessibleState;
import javax.accessibility.AccessibleStateSet;
import javax.swing.JComponent;
import javax.swing.JRootPane;

import sun.awt.AWTAccessor;
import sun.awt.AppContext;
import sun.awt.ComponentFactory;
import sun.awt.ConstrainableGraphics;
import sun.awt.EmbeddedFrame;
import sun.awt.RequestFocusController;
import sun.awt.SubRegionShowable;
import sun.awt.SunToolkit;
import sun.awt.dnd.SunDropTargetEvent;
import sun.awt.im.CompositionArea;
import sun.awt.image.VSyncedBSManager;
import sun.font.FontManager;
import sun.font.FontManagerFactory;
import sun.font.SunFontManager;
import sun.java2d.SunGraphics2D;
import sun.java2d.SunGraphicsEnvironment;
import sun.java2d.pipe.Region;
import sun.java2d.pipe.hw.ExtendedBufferCapabilities;
import sun.security.action.GetPropertyAction;
import sun.swing.SwingAccessor;
import sun.util.logging.PlatformLogger;

import static sun.java2d.pipe.hw.ExtendedBufferCapabilities.VSyncType.VSYNC_DEFAULT;
import static sun.java2d.pipe.hw.ExtendedBufferCapabilities.VSyncType.VSYNC_ON;


A component is an object having a graphical representation
that can be displayed on the screen and that can interact with the
user. Examples of components are the buttons, checkboxes, and scrollbars
of a typical graphical user interface. 
 The Component class is the abstract superclass of the nonmenu-related Abstract Window Toolkit components. Class Component can also be extended directly to create a lightweight component. A lightweight component is a component that is not associated with a native window. On the contrary, a heavyweight component is associated with a native window. The isLightweight() method may be used to distinguish between the two kinds of the components. 
 Lightweight and heavyweight components may be mixed in a single component hierarchy. However, for correct operating of such a mixed hierarchy of components, the whole hierarchy must be valid. When the hierarchy gets invalidated, like after changing the bounds of components, or adding/removing components to/from containers, the whole hierarchy must be validated afterwards by means of the Container.validate() method invoked on the top-most invalid container of the hierarchy. 
Serialization
 It is important to note that only AWT listeners which conform to the Serializable protocol will be saved when the object is stored. If an AWT object has listeners that aren't marked serializable, they will be dropped at writeObject time. Developers will need, as always, to consider the implications of making an object serializable. One situation to watch out for is this: 
   import java.awt.*;
   import java.awt.event.*;
   import java.io.Serializable;
   class MyApp implements ActionListener, Serializable
   {
       BigObjectThatShouldNotBeSerializedWithAButton bigOne;
       Button aButton = new Button();
       MyApp()
       {
           // Oops, now aButton has a listener with a reference
           // to bigOne!
           aButton.addActionListener(this);
       }
       public void actionPerformed(ActionEvent e)
       {
           System.out.println("Hello There");
       }
   }

 In this example, serializing aButton by itself will cause MyApp and everything it refers to to be serialized as well. The problem is that the listener is serializable by coincidence, not by design. To separate the decisions about MyApp and the ActionListener being serializable one can use a nested class, as in the following example: 
   import java.awt.*;
   import java.awt.event.*;
   import java.io.Serializable;
   class MyApp implements java.io.Serializable
   {
        BigObjectThatShouldNotBeSerializedWithAButton bigOne;
        Button aButton = new Button();
        static class MyActionListener implements ActionListener
        {
            public void actionPerformed(ActionEvent e)
            {
                System.out.println("Hello There");
            }
        }
        MyApp()
        {
            aButton.addActionListener(new MyActionListener());
        }
   }




Note: For more information on the paint mechanisms utilized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.


For details on the focus subsystem, see

How to Use the Focus Subsystem,
a section in The Java Tutorial, and the
Focus Specification
for more information.

Author:     Arthur van Hoff,      Sami Shaio
/**
 * A <em>component</em> is an object having a graphical representation
 * that can be displayed on the screen and that can interact with the
 * user. Examples of components are the buttons, checkboxes, and scrollbars
 * of a typical graphical user interface. <p>
 * The {@code Component} class is the abstract superclass of
 * the nonmenu-related Abstract Window Toolkit components. Class
 * {@code Component} can also be extended directly to create a
 * lightweight component. A lightweight component is a component that is
 * not associated with a native window. On the contrary, a heavyweight
 * component is associated with a native window. The {@link #isLightweight()}
 * method may be used to distinguish between the two kinds of the components.
 * <p>
 * Lightweight and heavyweight components may be mixed in a single component
 * hierarchy. However, for correct operating of such a mixed hierarchy of
 * components, the whole hierarchy must be valid. When the hierarchy gets
 * invalidated, like after changing the bounds of components, or
 * adding/removing components to/from containers, the whole hierarchy must be
 * validated afterwards by means of the {@link Container#validate()} method
 * invoked on the top-most invalid container of the hierarchy.
 *
 * <h3>Serialization</h3>
 * It is important to note that only AWT listeners which conform
 * to the {@code Serializable} protocol will be saved when
 * the object is stored.  If an AWT object has listeners that
 * aren't marked serializable, they will be dropped at
 * {@code writeObject} time.  Developers will need, as always,
 * to consider the implications of making an object serializable.
 * One situation to watch out for is this:
 * <pre>
 *    import java.awt.*;
 *    import java.awt.event.*;
 *    import java.io.Serializable;
 *
 *    class MyApp implements ActionListener, Serializable
 *    {
 *        BigObjectThatShouldNotBeSerializedWithAButton bigOne;
 *        Button aButton = new Button();
 *
 *        MyApp()
 *        {
 *            // Oops, now aButton has a listener with a reference
 *            // to bigOne!
 *            aButton.addActionListener(this);
 *        }
 *
 *        public void actionPerformed(ActionEvent e)
 *        {
 *            System.out.println("Hello There");
 *        }
 *    }
 * </pre>
 * In this example, serializing {@code aButton} by itself
 * will cause {@code MyApp} and everything it refers to
 * to be serialized as well.  The problem is that the listener
 * is serializable by coincidence, not by design.  To separate
 * the decisions about {@code MyApp} and the
 * {@code ActionListener} being serializable one can use a
 * nested class, as in the following example:
 * <pre>
 *    import java.awt.*;
 *    import java.awt.event.*;
 *    import java.io.Serializable;
 *
 *    class MyApp implements java.io.Serializable
 *    {
 *         BigObjectThatShouldNotBeSerializedWithAButton bigOne;
 *         Button aButton = new Button();
 *
 *         static class MyActionListener implements ActionListener
 *         {
 *             public void actionPerformed(ActionEvent e)
 *             {
 *                 System.out.println("Hello There");
 *             }
 *         }
 *
 *         MyApp()
 *         {
 *             aButton.addActionListener(new MyActionListener());
 *         }
 *    }
 * </pre>
 * <p>
 * <b>Note</b>: For more information on the paint mechanisms utilized
 * by AWT and Swing, including information on how to write the most
 * efficient painting code, see
 * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
 * <p>
 * For details on the focus subsystem, see
 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
 * How to Use the Focus Subsystem</a>,
 * a section in <em>The Java Tutorial</em>, and the
 * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
 * for more information.
 *
 * @author      Arthur van Hoff
 * @author      Sami Shaio
 */
public abstract class Component implements ImageObserver, MenuContainer,
                                           Serializable
{

    private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.Component");
    private static final PlatformLogger eventLog = PlatformLogger.getLogger("java.awt.event.Component");
    private static final PlatformLogger focusLog = PlatformLogger.getLogger("java.awt.focus.Component");
    private static final PlatformLogger mixingLog = PlatformLogger.getLogger("java.awt.mixing.Component");

    
The peer of the component. The peer implements the component's behavior. The peer is set when the Component is added to a container that also is a peer. 
See Also:
/**
     * The peer of the component. The peer implements the component's
     * behavior. The peer is set when the {@code Component} is
     * added to a container that also is a peer.
     * @see #addNotify
     * @see #removeNotify
     */
    transient volatile ComponentPeer peer;

    
The parent of the object. It may be null for top-level components. 
See Also:
/**
     * The parent of the object. It may be {@code null}
     * for top-level components.
     * @see #getParent
     */
    transient Container parent;

    
The AppContext of the component. Applets/Plugin may change the AppContext. 
/**
     * The {@code AppContext} of the component. Applets/Plugin may
     * change the AppContext.
     */
    transient AppContext appContext;

    
The x position of the component in the parent's coordinate system.

See Also:
@serial
/**
     * The x position of the component in the parent's coordinate system.
     *
     * @serial
     * @see #getLocation
     */
    int x;

    
The y position of the component in the parent's coordinate system.

See Also:
@serial
/**
     * The y position of the component in the parent's coordinate system.
     *
     * @serial
     * @see #getLocation
     */
    int y;

    
The width of the component.

See Also:
@serial
/**
     * The width of the component.
     *
     * @serial
     * @see #getSize
     */
    int width;

    
The height of the component.

See Also:
@serial
/**
     * The height of the component.
     *
     * @serial
     * @see #getSize
     */
    int height;

    
The foreground color for this component. foreground can be null. 
See Also:
@serial
/**
     * The foreground color for this component.
     * {@code foreground} can be {@code null}.
     *
     * @serial
     * @see #getForeground
     * @see #setForeground
     */
    Color       foreground;

    
The background color for this component. background can be null. 
See Also:
@serial
/**
     * The background color for this component.
     * {@code background} can be {@code null}.
     *
     * @serial
     * @see #getBackground
     * @see #setBackground
     */
    Color       background;

    
The font used by this component. The font can be null. 
See Also:
@serial
/**
     * The font used by this component.
     * The {@code font} can be {@code null}.
     *
     * @serial
     * @see #getFont
     * @see #setFont
     */
    volatile Font font;

    
The font which the peer is currently using. (null if no peer exists.) 
/**
     * The font which the peer is currently using.
     * ({@code null} if no peer exists.)
     */
    Font        peerFont;

    
The cursor displayed when pointer is over this component. This value can be null. 
See Also:
@serial
/**
     * The cursor displayed when pointer is over this component.
     * This value can be {@code null}.
     *
     * @serial
     * @see #getCursor
     * @see #setCursor
     */
    Cursor      cursor;

    
The locale for the component.

See Also:
@serial
/**
     * The locale for the component.
     *
     * @serial
     * @see #getLocale
     * @see #setLocale
     */
    Locale      locale;

    
A reference to a GraphicsConfiguration object used to describe the characteristics of a graphics destination. This value can be null. 
See Also:
Since:1.3
@serial
/**
     * A reference to a {@code GraphicsConfiguration} object
     * used to describe the characteristics of a graphics
     * destination.
     * This value can be {@code null}.
     *
     * @since 1.3
     * @serial
     * @see GraphicsConfiguration
     * @see #getGraphicsConfiguration
     */
    private transient volatile GraphicsConfiguration graphicsConfig;

    
A reference to a BufferStrategy object used to manipulate the buffers on this component. 
See Also:
Since:1.4
/**
     * A reference to a {@code BufferStrategy} object
     * used to manipulate the buffers on this component.
     *
     * @since 1.4
     * @see java.awt.image.BufferStrategy
     * @see #getBufferStrategy()
     */
    private transient BufferStrategy bufferStrategy = null;

    
True when the object should ignore all repaint events.

See Also:
Since:1.4
@serial
/**
     * True when the object should ignore all repaint events.
     *
     * @since 1.4
     * @serial
     * @see #setIgnoreRepaint
     * @see #getIgnoreRepaint
     */
    boolean ignoreRepaint = false;

    
True when the object is visible. An object that is not
visible is not drawn on the screen.

See Also:
@serial
/**
     * True when the object is visible. An object that is not
     * visible is not drawn on the screen.
     *
     * @serial
     * @see #isVisible
     * @see #setVisible
     */
    boolean visible = true;

    
True when the object is enabled. An object that is not
enabled does not interact with the user.

See Also:
@serial
/**
     * True when the object is enabled. An object that is not
     * enabled does not interact with the user.
     *
     * @serial
     * @see #isEnabled
     * @see #setEnabled
     */
    boolean enabled = true;

    
True when the object is valid. An invalid object needs to
be laid out. This flag is set to false when the object
size is changed.

See Also:
@serial
/**
     * True when the object is valid. An invalid object needs to
     * be laid out. This flag is set to false when the object
     * size is changed.
     *
     * @serial
     * @see #isValid
     * @see #validate
     * @see #invalidate
     */
    private volatile boolean valid = false;

    
The DropTarget associated with this component. 
See Also:
Since:1.2
@serial
/**
     * The {@code DropTarget} associated with this component.
     *
     * @since 1.2
     * @serial
     * @see #setDropTarget
     * @see #getDropTarget
     */
    DropTarget dropTarget;

    
See Also:
@serial
/**
     * @serial
     * @see #add
     */
    Vector<PopupMenu> popups;

    
A component's name. This field can be null. 
See Also:
@serial
/**
     * A component's name.
     * This field can be {@code null}.
     *
     * @serial
     * @see #getName
     * @see #setName(String)
     */
    private String name;

    
A bool to determine whether the name has been set explicitly. nameExplicitlySet will be false if the name has not been set and true if it has. 
See Also:
@serial
/**
     * A bool to determine whether the name has
     * been set explicitly. {@code nameExplicitlySet} will
     * be false if the name has not been set and
     * true if it has.
     *
     * @serial
     * @see #getName
     * @see #setName(String)
     */
    private boolean nameExplicitlySet = false;

    
Indicates whether this Component can be focused.

See Also:
@serial
Since:1.4
/**
     * Indicates whether this Component can be focused.
     *
     * @serial
     * @see #setFocusable
     * @see #isFocusable
     * @since 1.4
     */
    private boolean focusable = true;

    private static final int FOCUS_TRAVERSABLE_UNKNOWN = 0;
    private static final int FOCUS_TRAVERSABLE_DEFAULT = 1;
    private static final int FOCUS_TRAVERSABLE_SET = 2;

    
Tracks whether this Component is relying on default focus traversability.

@serial
Since:1.4
/**
     * Tracks whether this Component is relying on default focus traversability.
     *
     * @serial
     * @since 1.4
     */
    private int isFocusTraversableOverridden = FOCUS_TRAVERSABLE_UNKNOWN;

    
The focus traversal keys. These keys will generate focus traversal
behavior for Components for which focus traversal keys are enabled. If a
value of null is specified for a traversal key, this Component inherits
that traversal key from its parent. If all ancestors of this Component
have null specified for that traversal key, then the current
KeyboardFocusManager's default traversal key is used.

See Also:
@serial
Since:1.4
/**
     * The focus traversal keys. These keys will generate focus traversal
     * behavior for Components for which focus traversal keys are enabled. If a
     * value of null is specified for a traversal key, this Component inherits
     * that traversal key from its parent. If all ancestors of this Component
     * have null specified for that traversal key, then the current
     * KeyboardFocusManager's default traversal key is used.
     *
     * @serial
     * @see #setFocusTraversalKeys
     * @see #getFocusTraversalKeys
     * @since 1.4
     */
    Set<AWTKeyStroke>[] focusTraversalKeys;

    private static final String[] focusTraversalKeyPropertyNames = {
        "forwardFocusTraversalKeys",
        "backwardFocusTraversalKeys",
        "upCycleFocusTraversalKeys",
        "downCycleFocusTraversalKeys"
    };

    
Indicates whether focus traversal keys are enabled for this Component.
Components for which focus traversal keys are disabled receive key
events for focus traversal keys. Components for which focus traversal
keys are enabled do not see these events; instead, the events are
automatically converted to traversal operations.

See Also:
@serial
Since:1.4
/**
     * Indicates whether focus traversal keys are enabled for this Component.
     * Components for which focus traversal keys are disabled receive key
     * events for focus traversal keys. Components for which focus traversal
     * keys are enabled do not see these events; instead, the events are
     * automatically converted to traversal operations.
     *
     * @serial
     * @see #setFocusTraversalKeysEnabled
     * @see #getFocusTraversalKeysEnabled
     * @since 1.4
     */
    private boolean focusTraversalKeysEnabled = true;

    
The locking object for AWT component-tree and layout operations.

See Also:
  • getTreeLock
/**
     * The locking object for AWT component-tree and layout operations.
     *
     * @see #getTreeLock
     */
    static final Object LOCK = new AWTTreeLock();
    static class AWTTreeLock {}

    /*
     * The component's AccessControlContext.
     */
    private transient volatile AccessControlContext acc =
        AccessController.getContext();

    
Minimum size.
(This field perhaps should have been transient).

@serial
/**
     * Minimum size.
     * (This field perhaps should have been transient).
     *
     * @serial
     */
    Dimension minSize;

    
Whether or not setMinimumSize has been invoked with a non-null value.

/**
     * Whether or not setMinimumSize has been invoked with a non-null value.
     */
    boolean minSizeSet;

    
Preferred size.
(This field perhaps should have been transient).

@serial
/**
     * Preferred size.
     * (This field perhaps should have been transient).
     *
     * @serial
     */
    Dimension prefSize;

    
Whether or not setPreferredSize has been invoked with a non-null value.

/**
     * Whether or not setPreferredSize has been invoked with a non-null value.
     */
    boolean prefSizeSet;

    
Maximum size

@serial
/**
     * Maximum size
     *
     * @serial
     */
    Dimension maxSize;

    
Whether or not setMaximumSize has been invoked with a non-null value.

/**
     * Whether or not setMaximumSize has been invoked with a non-null value.
     */
    boolean maxSizeSet;

    
The orientation for this component.

See Also:
/**
     * The orientation for this component.
     * @see #getComponentOrientation
     * @see #setComponentOrientation
     */
    transient ComponentOrientation componentOrientation
    = ComponentOrientation.UNKNOWN;

    
newEventsOnly will be true if the event is one of the event types enabled for the component. It will then allow for normal processing to continue. If it is false the event is passed to the component's parent and up the ancestor tree until the event has been consumed. 
See Also:
@serial
/**
     * {@code newEventsOnly} will be true if the event is
     * one of the event types enabled for the component.
     * It will then allow for normal processing to
     * continue.  If it is false the event is passed
     * to the component's parent and up the ancestor
     * tree until the event has been consumed.
     *
     * @serial
     * @see #dispatchEvent
     */
    boolean newEventsOnly = false;
    transient ComponentListener componentListener;
    transient FocusListener focusListener;
    transient HierarchyListener hierarchyListener;
    transient HierarchyBoundsListener hierarchyBoundsListener;
    transient KeyListener keyListener;
    transient MouseListener mouseListener;
    transient MouseMotionListener mouseMotionListener;
    transient MouseWheelListener mouseWheelListener;
    transient InputMethodListener inputMethodListener;

    
Internal, constants for serialization 
/** Internal, constants for serialization */
    static final String actionListenerK = "actionL";
    static final String adjustmentListenerK = "adjustmentL";
    static final String componentListenerK = "componentL";
    static final String containerListenerK = "containerL";
    static final String focusListenerK = "focusL";
    static final String itemListenerK = "itemL";
    static final String keyListenerK = "keyL";
    static final String mouseListenerK = "mouseL";
    static final String mouseMotionListenerK = "mouseMotionL";
    static final String mouseWheelListenerK = "mouseWheelL";
    static final String textListenerK = "textL";
    static final String ownedWindowK = "ownedL";
    static final String windowListenerK = "windowL";
    static final String inputMethodListenerK = "inputMethodL";
    static final String hierarchyListenerK = "hierarchyL";
    static final String hierarchyBoundsListenerK = "hierarchyBoundsL";
    static final String windowStateListenerK = "windowStateL";
    static final String windowFocusListenerK = "windowFocusL";

    
The eventMask is ONLY set by subclasses via enableEvents. The mask should NOT be set when listeners are registered so that we can distinguish the difference between when listeners request events and subclasses request them. One bit is used to indicate whether input methods are enabled; this bit is set by enableInputMethods and is on by default. 
See Also:
@serial
/**
     * The {@code eventMask} is ONLY set by subclasses via
     * {@code enableEvents}.
     * The mask should NOT be set when listeners are registered
     * so that we can distinguish the difference between when
     * listeners request events and subclasses request them.
     * One bit is used to indicate whether input methods are
     * enabled; this bit is set by {@code enableInputMethods} and is
     * on by default.
     *
     * @serial
     * @see #enableInputMethods
     * @see AWTEvent
     */
    long eventMask = AWTEvent.INPUT_METHODS_ENABLED_MASK;

    
Static properties for incremental drawing.

See Also:
  • imageUpdate
/**
     * Static properties for incremental drawing.
     * @see #imageUpdate
     */
    static boolean isInc;
    static int incRate;
    static {
        /* ensure that the necessary native libraries are loaded */
        Toolkit.loadLibraries();
        /* initialize JNI field and method ids */
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }

        String s = java.security.AccessController.doPrivileged(
                                                               new GetPropertyAction("awt.image.incrementaldraw"));
        isInc = (s == null || s.equals("true"));

        s = java.security.AccessController.doPrivileged(
                                                        new GetPropertyAction("awt.image.redrawrate"));
        incRate = (s != null) ? Integer.parseInt(s) : 100;
    }

    
Ease-of-use constant for getAlignmentY(). Specifies an alignment to the top of the component. 
See Also:
/**
     * Ease-of-use constant for {@code getAlignmentY()}.
     * Specifies an alignment to the top of the component.
     * @see     #getAlignmentY
     */
    public static final float TOP_ALIGNMENT = 0.0f;

    
Ease-of-use constant for getAlignmentY and getAlignmentX. Specifies an alignment to the center of the component 
See Also:
/**
     * Ease-of-use constant for {@code getAlignmentY} and
     * {@code getAlignmentX}. Specifies an alignment to
     * the center of the component
     * @see     #getAlignmentX
     * @see     #getAlignmentY
     */
    public static final float CENTER_ALIGNMENT = 0.5f;

    
Ease-of-use constant for getAlignmentY. Specifies an alignment to the bottom of the component. 
See Also:
/**
     * Ease-of-use constant for {@code getAlignmentY}.
     * Specifies an alignment to the bottom of the component.
     * @see     #getAlignmentY
     */
    public static final float BOTTOM_ALIGNMENT = 1.0f;

    
Ease-of-use constant for getAlignmentX. Specifies an alignment to the left side of the component. 
See Also:
/**
     * Ease-of-use constant for {@code getAlignmentX}.
     * Specifies an alignment to the left side of the component.
     * @see     #getAlignmentX
     */
    public static final float LEFT_ALIGNMENT = 0.0f;

    
Ease-of-use constant for getAlignmentX. Specifies an alignment to the right side of the component. 
See Also:
/**
     * Ease-of-use constant for {@code getAlignmentX}.
     * Specifies an alignment to the right side of the component.
     * @see     #getAlignmentX
     */
    public static final float RIGHT_ALIGNMENT = 1.0f;

    /*
     * JDK 1.1 serialVersionUID
     */
    private static final long serialVersionUID = -7644114512714619750L;

    
If any PropertyChangeListeners have been registered, the changeSupport field describes them. 
See Also:
@serial
Since:1.2
/**
     * If any {@code PropertyChangeListeners} have been registered,
     * the {@code changeSupport} field describes them.
     *
     * @serial
     * @since 1.2
     * @see #addPropertyChangeListener
     * @see #removePropertyChangeListener
     * @see #firePropertyChange
     */
    private PropertyChangeSupport changeSupport;

    /*
     * In some cases using "this" as an object to synchronize by
     * can lead to a deadlock if client code also uses synchronization
     * by a component object. For every such situation revealed we should
     * consider possibility of replacing "this" with the package private
     * objectLock object introduced below. So far there are 3 issues known:
     * - CR 6708322 (the getName/setName methods);
     * - CR 6608764 (the PropertyChangeListener machinery);
     * - CR 7108598 (the Container.paint/KeyboardFocusManager.clearMostRecentFocusOwner methods).
     *
     * Note: this field is considered final, though readObject() prohibits
     * initializing final fields.
     */
    private transient Object objectLock = new Object();
    Object getObjectLock() {
        return objectLock;
    }

    /*
     * Returns the acc this component was constructed with.
     */
    final AccessControlContext getAccessControlContext() {
        if (acc == null) {
            throw new SecurityException("Component is missing AccessControlContext");
        }
        return acc;
    }

    boolean isPacked = false;

    
Pseudoparameter for direct Geometry API (setLocation, setBounds setSize
to signal setBounds what's changing. Should be used under TreeLock.
This is only needed due to the inability to change the cross-calling
order of public and deprecated methods.

/**
     * Pseudoparameter for direct Geometry API (setLocation, setBounds setSize
     * to signal setBounds what's changing. Should be used under TreeLock.
     * This is only needed due to the inability to change the cross-calling
     * order of public and deprecated methods.
     */
    private int boundsOp = ComponentPeer.DEFAULT_OPERATION;

    
Enumeration of the common ways the baseline of a component can change as the size changes. The baseline resize behavior is primarily for layout managers that need to know how the position of the baseline changes as the component size changes. In general the baseline resize behavior will be valid for sizes greater than or equal to the minimum size (the actual minimum size; not a developer specified minimum size). For sizes smaller than the minimum size the baseline may change in a way other than the baseline resize behavior indicates. Similarly, as the size approaches Integer.MAX_VALUE and/or Short.MAX_VALUE the baseline may change in a way other than the baseline resize behavior indicates. 
See Also:
Since:1.6
/**
     * Enumeration of the common ways the baseline of a component can
     * change as the size changes.  The baseline resize behavior is
     * primarily for layout managers that need to know how the
     * position of the baseline changes as the component size changes.
     * In general the baseline resize behavior will be valid for sizes
     * greater than or equal to the minimum size (the actual minimum
     * size; not a developer specified minimum size).  For sizes
     * smaller than the minimum size the baseline may change in a way
     * other than the baseline resize behavior indicates.  Similarly,
     * as the size approaches {@code Integer.MAX_VALUE} and/or
     * {@code Short.MAX_VALUE} the baseline may change in a way
     * other than the baseline resize behavior indicates.
     *
     * @see #getBaselineResizeBehavior
     * @see #getBaseline(int,int)
     * @since 1.6
     */
    public enum BaselineResizeBehavior {
        
Indicates the baseline remains fixed relative to the y-origin. That is, getBaseline returns the same value regardless of the height or width. For example, a JLabel containing non-empty text with a vertical alignment of TOP should have a baseline type of CONSTANT_ASCENT. 
/**
         * Indicates the baseline remains fixed relative to the
         * y-origin.  That is, {@code getBaseline} returns
         * the same value regardless of the height or width.  For example, a
         * {@code JLabel} containing non-empty text with a
         * vertical alignment of {@code TOP} should have a
         * baseline type of {@code CONSTANT_ASCENT}.
         */
        CONSTANT_ASCENT,

        
Indicates the baseline remains fixed relative to the height and does not change as the width is varied. That is, for any height H the difference between H and getBaseline(w, H) is the same. For example, a JLabel containing non-empty text with a vertical alignment of BOTTOM should have a baseline type of CONSTANT_DESCENT. 
/**
         * Indicates the baseline remains fixed relative to the height
         * and does not change as the width is varied.  That is, for
         * any height H the difference between H and
         * {@code getBaseline(w, H)} is the same.  For example, a
         * {@code JLabel} containing non-empty text with a
         * vertical alignment of {@code BOTTOM} should have a
         * baseline type of {@code CONSTANT_DESCENT}.
         */
        CONSTANT_DESCENT,

        
Indicates the baseline remains a fixed distance from the center of the component. That is, for any height H the difference between getBaseline(w, H) and H / 2 is the same (plus or minus one depending upon rounding error). 

Because of possible rounding errors it is recommended
you ask for the baseline with two consecutive heights and use
the return value to determine if you need to pad calculations
by 1.  The following shows how to calculate the baseline for
any height:

  Dimension preferredSize = component.getPreferredSize();
  int baseline = getBaseline(preferredSize.width,
                             preferredSize.height);
  int nextBaseline = getBaseline(preferredSize.width,
                                 preferredSize.height + 1);
  // Amount to add to height when calculating where baseline
  // lands for a particular height:
  int padding = 0;
  // Where the baseline is relative to the mid point
  int baselineOffset = baseline - height / 2;
  if (preferredSize.height % 2 == 0 &&
      baseline != nextBaseline) {
      padding = 1;
  }
  else if (preferredSize.height % 2 == 1 &&
           baseline == nextBaseline) {
      baselineOffset--;
      padding = 1;
  }
  // The following calculates where the baseline lands for
  // the height z:
  int calculatedBaseline = (z + padding) / 2 + baselineOffset;



/**
         * Indicates the baseline remains a fixed distance from
         * the center of the component.  That is, for any height H the
         * difference between {@code getBaseline(w, H)} and
         * {@code H / 2} is the same (plus or minus one depending upon
         * rounding error).
         * <p>
         * Because of possible rounding errors it is recommended
         * you ask for the baseline with two consecutive heights and use
         * the return value to determine if you need to pad calculations
         * by 1.  The following shows how to calculate the baseline for
         * any height:
         * <pre>
         *   Dimension preferredSize = component.getPreferredSize();
         *   int baseline = getBaseline(preferredSize.width,
         *                              preferredSize.height);
         *   int nextBaseline = getBaseline(preferredSize.width,
         *                                  preferredSize.height + 1);
         *   // Amount to add to height when calculating where baseline
         *   // lands for a particular height:
         *   int padding = 0;
         *   // Where the baseline is relative to the mid point
         *   int baselineOffset = baseline - height / 2;
         *   if (preferredSize.height % 2 == 0 &amp;&amp;
         *       baseline != nextBaseline) {
         *       padding = 1;
         *   }
         *   else if (preferredSize.height % 2 == 1 &amp;&amp;
         *            baseline == nextBaseline) {
         *       baselineOffset--;
         *       padding = 1;
         *   }
         *   // The following calculates where the baseline lands for
         *   // the height z:
         *   int calculatedBaseline = (z + padding) / 2 + baselineOffset;
         * </pre>
         */
        CENTER_OFFSET,

        
Indicates the baseline resize behavior can not be expressed using
any of the other constants.  This may also indicate the baseline
varies with the width of the component.  This is also returned
by components that do not have a baseline.

/**
         * Indicates the baseline resize behavior can not be expressed using
         * any of the other constants.  This may also indicate the baseline
         * varies with the width of the component.  This is also returned
         * by components that do not have a baseline.
         */
        OTHER
    }

    /*
     * The shape set with the applyCompoundShape() method. It includes the result
     * of the HW/LW mixing related shape computation. It may also include
     * the user-specified shape of the component.
     * The 'null' value means the component has normal shape (or has no shape at all)
     * and applyCompoundShape() will skip the following shape identical to normal.
     */
    private transient Region compoundShape = null;

    /*
     * Represents the shape of this lightweight component to be cut out from
     * heavyweight components should they intersect. Possible values:
     *    1. null - consider the shape rectangular
     *    2. EMPTY_REGION - nothing gets cut out (children still get cut out)
     *    3. non-empty - this shape gets cut out.
     */
    private transient Region mixingCutoutRegion = null;

    /*
     * Indicates whether addNotify() is complete
     * (i.e. the peer is created).
     */
    private transient boolean isAddNotifyComplete = false;

    
Should only be used in subclass getBounds to check that part of bounds
is actually changing

/**
     * Should only be used in subclass getBounds to check that part of bounds
     * is actually changing
     */
    int getBoundsOp() {
        assert Thread.holdsLock(getTreeLock());
        return boundsOp;
    }

    void setBoundsOp(int op) {
        assert Thread.holdsLock(getTreeLock());
        if (op == ComponentPeer.RESET_OPERATION) {
            boundsOp = ComponentPeer.DEFAULT_OPERATION;
        } else
            if (boundsOp == ComponentPeer.DEFAULT_OPERATION) {
                boundsOp = op;
            }
    }

    // Whether this Component has had the background erase flag
    // specified via SunToolkit.disableBackgroundErase(). This is
    // needed in order to make this function work on X11 platforms,
    // where currently there is no chance to interpose on the creation
    // of the peer and therefore the call to XSetBackground.
    transient boolean backgroundEraseDisabled;

    static {
        AWTAccessor.setComponentAccessor(new AWTAccessor.ComponentAccessor() {
            public void setBackgroundEraseDisabled(Component comp, boolean disabled) {
                comp.backgroundEraseDisabled = disabled;
            }
            public boolean getBackgroundEraseDisabled(Component comp) {
                return comp.backgroundEraseDisabled;
            }
            public Rectangle getBounds(Component comp) {
                return new Rectangle(comp.x, comp.y, comp.width, comp.height);
            }
            public void setGraphicsConfiguration(Component comp,
                    GraphicsConfiguration gc)
            {
                comp.setGraphicsConfiguration(gc);
            }
            public void requestFocus(Component comp, FocusEvent.Cause cause) {
                comp.requestFocus(cause);
            }
            public boolean canBeFocusOwner(Component comp) {
                return comp.canBeFocusOwner();
            }

            public boolean isVisible(Component comp) {
                return comp.isVisible_NoClientCode();
            }
            public void setRequestFocusController
                (RequestFocusController requestController)
            {
                 Component.setRequestFocusController(requestController);
            }
            public AppContext getAppContext(Component comp) {
                 return comp.appContext;
            }
            public void setAppContext(Component comp, AppContext appContext) {
                 comp.appContext = appContext;
            }
            public Container getParent(Component comp) {
                return comp.getParent_NoClientCode();
            }
            public void setParent(Component comp, Container parent) {
                comp.parent = parent;
            }
            public void setSize(Component comp, int width, int height) {
                comp.width = width;
                comp.height = height;
            }
            public Point getLocation(Component comp) {
                return comp.location_NoClientCode();
            }
            public void setLocation(Component comp, int x, int y) {
                comp.x = x;
                comp.y = y;
            }
            public boolean isEnabled(Component comp) {
                return comp.isEnabledImpl();
            }
            public boolean isDisplayable(Component comp) {
                return comp.peer != null;
            }
            public Cursor getCursor(Component comp) {
                return comp.getCursor_NoClientCode();
            }
            @SuppressWarnings("unchecked")
            public <T extends ComponentPeer> T getPeer(Component comp) {
                return (T) comp.peer;
            }
            public void setPeer(Component comp, ComponentPeer peer) {
                comp.peer = peer;
            }
            public boolean isLightweight(Component comp) {
                return (comp.peer instanceof LightweightPeer);
            }
            public boolean getIgnoreRepaint(Component comp) {
                return comp.ignoreRepaint;
            }
            public int getWidth(Component comp) {
                return comp.width;
            }
            public int getHeight(Component comp) {
                return comp.height;
            }
            public int getX(Component comp) {
                return comp.x;
            }
            public int getY(Component comp) {
                return comp.y;
            }
            public Color getForeground(Component comp) {
                return comp.foreground;
            }
            public Color getBackground(Component comp) {
                return comp.background;
            }
            public void setBackground(Component comp, Color background) {
                comp.background = background;
            }
            public Font getFont(Component comp) {
                return comp.getFont_NoClientCode();
            }
            public void processEvent(Component comp, AWTEvent e) {
                comp.processEvent(e);
            }

            public AccessControlContext getAccessControlContext(Component comp) {
                return comp.getAccessControlContext();
            }

            public void revalidateSynchronously(Component comp) {
                comp.revalidateSynchronously();
            }

            @Override
            public void createBufferStrategy(Component comp, int numBuffers,
                    BufferCapabilities caps) throws AWTException {
                comp.createBufferStrategy(numBuffers, caps);
            }

            @Override
            public BufferStrategy getBufferStrategy(Component comp) {
                return comp.getBufferStrategy();
            }
        });
    }

    
Constructs a new component. Class Component can be extended directly to create a lightweight component that does not utilize an opaque native window. A lightweight component must be hosted by a native container somewhere higher up in the component tree (for example, by a Frame object). 
/**
     * Constructs a new component. Class {@code Component} can be
     * extended directly to create a lightweight component that does not
     * utilize an opaque native window. A lightweight component must be
     * hosted by a native container somewhere higher up in the component
     * tree (for example, by a {@code Frame} object).
     */
    protected Component() {
        appContext = AppContext.getAppContext();
    }

    @SuppressWarnings({"rawtypes", "unchecked"})
    void initializeFocusTraversalKeys() {
        focusTraversalKeys = new Set[3];
    }

    
Constructs a name for this component. Called by getName when the name is null. 
/**
     * Constructs a name for this component.  Called by {@code getName}
     * when the name is {@code null}.
     */
    String constructComponentName() {
        return null; // For strict compliance with prior platform versions, a Component
                     // that doesn't set its name should return null from
                     // getName()
    }

    
Gets the name of the component.

See Also:
Returns:this component's name
Since:1.1
/**
     * Gets the name of the component.
     * @return this component's name
     * @see    #setName
     * @since 1.1
     */
    public String getName() {
        if (name == null && !nameExplicitlySet) {
            synchronized(getObjectLock()) {
                if (name == null && !nameExplicitlySet)
                    name = constructComponentName();
            }
        }
        return name;
    }

    
Sets the name of the component to the specified string.

Params:
  • name –  the string that is to be this
          component's name
See Also:
Since:1.1
/**
     * Sets the name of the component to the specified string.
     * @param name  the string that is to be this
     *           component's name
     * @see #getName
     * @since 1.1
     */
    public void setName(String name) {
        String oldName;
        synchronized(getObjectLock()) {
            oldName = this.name;
            this.name = name;
            nameExplicitlySet = true;
        }
        firePropertyChange("name", oldName, name);
    }

    
Gets the parent of this component.

Returns:the parent container of this component
Since:1.0
/**
     * Gets the parent of this component.
     * @return the parent container of this component
     * @since 1.0
     */
    public Container getParent() {
        return getParent_NoClientCode();
    }

    // NOTE: This method may be called by privileged threads.
    //       This functionality is implemented in a package-private method
    //       to insure that it cannot be overridden by client subclasses.
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
    final Container getParent_NoClientCode() {
        return parent;
    }

    // This method is overridden in the Window class to return null,
    //    because the parent field of the Window object contains
    //    the owner of the window, not its parent.
    Container getContainer() {
        return getParent_NoClientCode();
    }

    
Associate a DropTarget with this component. The Component will receive drops only if it is enabled. 
Params:
  • dt – The DropTarget
See Also:
/**
     * Associate a {@code DropTarget} with this component.
     * The {@code Component} will receive drops only if it
     * is enabled.
     *
     * @see #isEnabled
     * @param dt The DropTarget
     */

    public synchronized void setDropTarget(DropTarget dt) {
        if (dt == dropTarget || (dropTarget != null && dropTarget.equals(dt)))
            return;

        DropTarget old;

        if ((old = dropTarget) != null) {
            dropTarget.removeNotify();

            DropTarget t = dropTarget;

            dropTarget = null;

            try {
                t.setComponent(null);
            } catch (IllegalArgumentException iae) {
                // ignore it.
            }
        }

        // if we have a new one, and we have a peer, add it!

        if ((dropTarget = dt) != null) {
            try {
                dropTarget.setComponent(this);
                dropTarget.addNotify();
            } catch (IllegalArgumentException iae) {
                if (old != null) {
                    try {
                        old.setComponent(this);
                        dropTarget.addNotify();
                    } catch (IllegalArgumentException iae1) {
                        // ignore it!
                    }
                }
            }
        }
    }

    
Gets the DropTarget associated with this Component. 
Returns:the drop target
/**
     * Gets the {@code DropTarget} associated with this
     * {@code Component}.
     *
     * @return the drop target
     */

    public synchronized DropTarget getDropTarget() { return dropTarget; }

    
Gets the GraphicsConfiguration associated with this Component. If the Component has not been assigned a specific GraphicsConfiguration, the GraphicsConfiguration of the Component object's top-level container is returned. If the Component has been created, but not yet added to a Container, this method returns null. 
Returns:the GraphicsConfiguration used by this Component or null
Since:1.3
/**
     * Gets the {@code GraphicsConfiguration} associated with this
     * {@code Component}.
     * If the {@code Component} has not been assigned a specific
     * {@code GraphicsConfiguration},
     * the {@code GraphicsConfiguration} of the
     * {@code Component} object's top-level container is
     * returned.
     * If the {@code Component} has been created, but not yet added
     * to a {@code Container}, this method returns {@code null}.
     *
     * @return the {@code GraphicsConfiguration} used by this
     *          {@code Component} or {@code null}
     * @since 1.3
     */
    public GraphicsConfiguration getGraphicsConfiguration() {
        return getGraphicsConfiguration_NoClientCode();
    }

    final GraphicsConfiguration getGraphicsConfiguration_NoClientCode() {
        return graphicsConfig;
    }

    void setGraphicsConfiguration(GraphicsConfiguration gc) {
        synchronized(getTreeLock()) {
            if (updateGraphicsData(gc)) {
                removeNotify();
                addNotify();
            }
        }
    }

    final boolean updateGraphicsData(GraphicsConfiguration gc) {
        GraphicsConfiguration oldConfig = graphicsConfig;
        // First, update own graphics configuration
        boolean ret = updateSelfGraphicsData(gc);
        // Second, update children graphics configurations
        ret |= updateChildGraphicsData(gc);
        // Third, fire PropertyChange if needed
        if (oldConfig != gc) {
            /*
             * If component is moved from one screen to another screen or shown
             * for the first time graphicsConfiguration property is fired to
             * enable the component to recalculate any rendering data, if needed
             */
            firePropertyChange("graphicsConfiguration", oldConfig, gc);
        }
        return ret;
    }

    private boolean updateSelfGraphicsData(GraphicsConfiguration gc) {
        checkTreeLock();
        if (graphicsConfig == gc) {
            return false;
        }
        graphicsConfig = gc;

        ComponentPeer peer = this.peer;
        if (peer != null) {
            return peer.updateGraphicsData(gc);
        }
        return false;
    }

    boolean updateChildGraphicsData(GraphicsConfiguration gc) {
        return false;
    }

    
Checks that this component's GraphicsDevice idString matches the string argument. 
/**
     * Checks that this component's {@code GraphicsDevice}
     * {@code idString} matches the string argument.
     */
    void checkGD(String stringID) {
        if (graphicsConfig != null) {
            if (!graphicsConfig.getDevice().getIDstring().equals(stringID)) {
                throw new IllegalArgumentException(
                                                   "adding a container to a container on a different GraphicsDevice");
            }
        }
    }

    
Gets this component's locking object (the object that owns the thread
synchronization monitor) for AWT component-tree and layout
operations.

Returns:this component's locking object
/**
     * Gets this component's locking object (the object that owns the thread
     * synchronization monitor) for AWT component-tree and layout
     * operations.
     * @return this component's locking object
     */
    public final Object getTreeLock() {
        return LOCK;
    }

    final void checkTreeLock() {
        if (!Thread.holdsLock(getTreeLock())) {
            throw new IllegalStateException("This function should be called while holding treeLock");
        }
    }

    
Gets the toolkit of this component. Note that
the frame that contains a component controls which
toolkit is used by that component. Therefore if the component
is moved from one frame to another, the toolkit it uses may change.

Returns: the toolkit of this component
Since:1.0
/**
     * Gets the toolkit of this component. Note that
     * the frame that contains a component controls which
     * toolkit is used by that component. Therefore if the component
     * is moved from one frame to another, the toolkit it uses may change.
     * @return  the toolkit of this component
     * @since 1.0
     */
    public Toolkit getToolkit() {
        return getToolkitImpl();
    }

    /*
     * This is called by the native code, so client code can't
     * be called on the toolkit thread.
     */
    final Toolkit getToolkitImpl() {
        Container parent = this.parent;
        if (parent != null) {
            return parent.getToolkitImpl();
        }
        return Toolkit.getDefaultToolkit();
    }

    final ComponentFactory getComponentFactory() {
        final Toolkit toolkit = getToolkit();
        if (toolkit instanceof ComponentFactory) {
            return (ComponentFactory) toolkit;
        }
        throw new AWTError("UI components are unsupported by: " + toolkit);
    }

    
Determines whether this component is valid. A component is valid
when it is correctly sized and positioned within its parent
container and all its children are also valid.
In order to account for peers' size requirements, components are invalidated
before they are first shown on the screen. By the time the parent container
is fully realized, all its components will be valid.

See Also:
Returns:true if the component is valid, false otherwise
Since:1.0
/**
     * Determines whether this component is valid. A component is valid
     * when it is correctly sized and positioned within its parent
     * container and all its children are also valid.
     * In order to account for peers' size requirements, components are invalidated
     * before they are first shown on the screen. By the time the parent container
     * is fully realized, all its components will be valid.
     * @return {@code true} if the component is valid, {@code false}
     * otherwise
     * @see #validate
     * @see #invalidate
     * @since 1.0
     */
    public boolean isValid() {
        return (peer != null) && valid;
    }

    
Determines whether this component is displayable. A component is
displayable when it is connected to a native screen resource.


A component is made displayable either when it is added to
a displayable containment hierarchy or when its containment
hierarchy is made displayable.
A containment hierarchy is made displayable when its ancestor
window is either packed or made visible.


A component is made undisplayable either when it is removed from
a displayable containment hierarchy or when its containment hierarchy
is made undisplayable.  A containment hierarchy is made
undisplayable when its ancestor window is disposed.

See Also:
Returns:true if the component is displayable, false otherwise
Since:1.2
/**
     * Determines whether this component is displayable. A component is
     * displayable when it is connected to a native screen resource.
     * <p>
     * A component is made displayable either when it is added to
     * a displayable containment hierarchy or when its containment
     * hierarchy is made displayable.
     * A containment hierarchy is made displayable when its ancestor
     * window is either packed or made visible.
     * <p>
     * A component is made undisplayable either when it is removed from
     * a displayable containment hierarchy or when its containment hierarchy
     * is made undisplayable.  A containment hierarchy is made
     * undisplayable when its ancestor window is disposed.
     *
     * @return {@code true} if the component is displayable,
     * {@code false} otherwise
     * @see Container#add(Component)
     * @see Window#pack
     * @see Window#show
     * @see Container#remove(Component)
     * @see Window#dispose
     * @since 1.2
     */
    public boolean isDisplayable() {
        return peer != null;
    }

    
Determines whether this component should be visible when its parent is visible. Components are initially visible, with the exception of top level components such as Frame objects. 
See Also:
Returns:true if the component is visible, false otherwise
Since:1.0
/**
     * Determines whether this component should be visible when its
     * parent is visible. Components are
     * initially visible, with the exception of top level components such
     * as {@code Frame} objects.
     * @return {@code true} if the component is visible,
     * {@code false} otherwise
     * @see #setVisible
     * @since 1.0
     */
    @Transient
    public boolean isVisible() {
        return isVisible_NoClientCode();
    }
    final boolean isVisible_NoClientCode() {
        return visible;
    }

    
Determines whether this component will be displayed on the screen.

Returns:true if the component and all of its ancestors until a toplevel window or null parent are visible, false otherwise
/**
     * Determines whether this component will be displayed on the screen.
     * @return {@code true} if the component and all of its ancestors
     *          until a toplevel window or null parent are visible,
     *          {@code false} otherwise
     */
    boolean isRecursivelyVisible() {
        return visible && (parent == null || parent.isRecursivelyVisible());
    }

    
Determines the bounds of a visible part of the component relative to its
parent.

Returns:the visible part of bounds
/**
     * Determines the bounds of a visible part of the component relative to its
     * parent.
     *
     * @return the visible part of bounds
     */
    private Rectangle getRecursivelyVisibleBounds() {
        final Component container = getContainer();
        final Rectangle bounds = getBounds();
        if (container == null) {
            // we are top level window or haven't a container, return our bounds
            return bounds;
        }
        // translate the container's bounds to our coordinate space
        final Rectangle parentsBounds = container.getRecursivelyVisibleBounds();
        parentsBounds.setLocation(0, 0);
        return parentsBounds.intersection(bounds);
    }

    
Translates absolute coordinates into coordinates in the coordinate
space of this component.

/**
     * Translates absolute coordinates into coordinates in the coordinate
     * space of this component.
     */
    Point pointRelativeToComponent(Point absolute) {
        Point compCoords = getLocationOnScreen();
        return new Point(absolute.x - compCoords.x,
                         absolute.y - compCoords.y);
    }

    
Assuming that mouse location is stored in PointerInfo passed
to this method, it finds a Component that is in the same
Window as this Component and is located under the mouse pointer.
If no such Component exists, null is returned.
NOTE: this method should be called under the protection of
tree lock, as it is done in Component.getMousePosition() and
Container.getMousePosition(boolean).

/**
     * Assuming that mouse location is stored in PointerInfo passed
     * to this method, it finds a Component that is in the same
     * Window as this Component and is located under the mouse pointer.
     * If no such Component exists, null is returned.
     * NOTE: this method should be called under the protection of
     * tree lock, as it is done in Component.getMousePosition() and
     * Container.getMousePosition(boolean).
     */
    Component findUnderMouseInWindow(PointerInfo pi) {
        if (!isShowing()) {
            return null;
        }
        Window win = getContainingWindow();
        Toolkit toolkit = Toolkit.getDefaultToolkit();
        if (!(toolkit instanceof ComponentFactory)) {
            return null;
        }
        if (!((ComponentFactory) toolkit).getMouseInfoPeer().isWindowUnderMouse(win)) {
            return null;
        }
        final boolean INCLUDE_DISABLED = true;
        Point relativeToWindow = win.pointRelativeToComponent(pi.getLocation());
        Component inTheSameWindow = win.findComponentAt(relativeToWindow.x,
                                                        relativeToWindow.y,
                                                        INCLUDE_DISABLED);
        return inTheSameWindow;
    }

    
Returns the position of the mouse pointer in this Component's coordinate space if the Component is directly under the mouse pointer, otherwise returns null. If the Component is not showing on the screen, this method returns null even if the mouse pointer is above the area where the Component would be displayed. If the Component is partially or fully obscured by other Components or native windows, this method returns a non-null value only if the mouse pointer is located above the unobscured part of the Component. 
 For Containers it returns a non-null value if the mouse is above the Container itself or above any of its descendants. Use Container.getMousePosition(boolean) if you need to exclude children. 
 Sometimes the exact mouse coordinates are not important, and the only thing that matters is whether a specific Component is under the mouse pointer. If the return value of this method is null, mouse pointer is not directly above the Component. 
Throws:
See Also:
Returns: mouse coordinates relative to this Component, or null
Since:    1.5
/**
     * Returns the position of the mouse pointer in this {@code Component}'s
     * coordinate space if the {@code Component} is directly under the mouse
     * pointer, otherwise returns {@code null}.
     * If the {@code Component} is not showing on the screen, this method
     * returns {@code null} even if the mouse pointer is above the area
     * where the {@code Component} would be displayed.
     * If the {@code Component} is partially or fully obscured by other
     * {@code Component}s or native windows, this method returns a non-null
     * value only if the mouse pointer is located above the unobscured part of the
     * {@code Component}.
     * <p>
     * For {@code Container}s it returns a non-null value if the mouse is
     * above the {@code Container} itself or above any of its descendants.
     * Use {@link Container#getMousePosition(boolean)} if you need to exclude children.
     * <p>
     * Sometimes the exact mouse coordinates are not important, and the only thing
     * that matters is whether a specific {@code Component} is under the mouse
     * pointer. If the return value of this method is {@code null}, mouse
     * pointer is not directly above the {@code Component}.
     *
     * @exception HeadlessException if GraphicsEnvironment.isHeadless() returns true
     * @see       #isShowing
     * @see       Container#getMousePosition
     * @return    mouse coordinates relative to this {@code Component}, or null
     * @since     1.5
     */
    public Point getMousePosition() throws HeadlessException {
        if (GraphicsEnvironment.isHeadless()) {
            throw new HeadlessException();
        }

        PointerInfo pi = java.security.AccessController.doPrivileged(
                                                                     new java.security.PrivilegedAction<PointerInfo>() {
                                                                         public PointerInfo run() {
                                                                             return MouseInfo.getPointerInfo();
                                                                         }
                                                                     }
                                                                     );

        synchronized (getTreeLock()) {
            Component inTheSameWindow = findUnderMouseInWindow(pi);
            if (!isSameOrAncestorOf(inTheSameWindow, true)) {
                return null;
            }
            return pointRelativeToComponent(pi.getLocation());
        }
    }

    
Overridden in Container. Must be called under TreeLock.

/**
     * Overridden in Container. Must be called under TreeLock.
     */
    boolean isSameOrAncestorOf(Component comp, boolean allowChildren) {
        return comp == this;
    }

    
Determines whether this component is showing on screen. This means
that the component must be visible, and it must be in a container
that is visible and showing.


Note: sometimes there is no way to detect whether the Component is actually visible to the user. This can happen when: 
    

  • the component has been added to a visible ScrollPane but the Component is not currently in the scroll pane's view port. 
  • the Component is obscured by another Component or Container. 


See Also:
Returns:true if the component is showing, false otherwise
Since:1.0
/**
     * Determines whether this component is showing on screen. This means
     * that the component must be visible, and it must be in a container
     * that is visible and showing.
     * <p>
     * <strong>Note:</strong> sometimes there is no way to detect whether the
     * {@code Component} is actually visible to the user.  This can happen when:
     * <ul>
     * <li>the component has been added to a visible {@code ScrollPane} but
     * the {@code Component} is not currently in the scroll pane's view port.
     * <li>the {@code Component} is obscured by another {@code Component} or
     * {@code Container}.
     * </ul>
     * @return {@code true} if the component is showing,
     *          {@code false} otherwise
     * @see #setVisible
     * @since 1.0
     */
    public boolean isShowing() {
        if (visible && (peer != null)) {
            Container parent = this.parent;
            return (parent == null) || parent.isShowing();
        }
        return false;
    }

    
Determines whether this component is enabled. An enabled component can respond to user input and generate events. Components are enabled initially by default. A component may be enabled or disabled by calling its setEnabled method. 
See Also:
Returns:true if the component is enabled, false otherwise
Since:1.0
/**
     * Determines whether this component is enabled. An enabled component
     * can respond to user input and generate events. Components are
     * enabled initially by default. A component may be enabled or disabled by
     * calling its {@code setEnabled} method.
     * @return {@code true} if the component is enabled,
     *          {@code false} otherwise
     * @see #setEnabled
     * @since 1.0
     */
    public boolean isEnabled() {
        return isEnabledImpl();
    }

    /*
     * This is called by the native code, so client code can't
     * be called on the toolkit thread.
     */
    final boolean isEnabledImpl() {
        return enabled;
    }

    
Enables or disables this component, depending on the value of the parameter b. An enabled component can respond to user input and generate events. Components are enabled initially by default. 
Note: Disabling a lightweight component does not prevent it from
receiving MouseEvents.

Note: Disabling a heavyweight container prevents all components
in this container from receiving any input events.  But disabling a
lightweight container affects only this container.

Params:
  • b –  If true, this component is enabled; otherwise this component is disabled
See Also:
Since:1.1
/**
     * Enables or disables this component, depending on the value of the
     * parameter {@code b}. An enabled component can respond to user
     * input and generate events. Components are enabled initially by default.
     *
     * <p>Note: Disabling a lightweight component does not prevent it from
     * receiving MouseEvents.
     * <p>Note: Disabling a heavyweight container prevents all components
     * in this container from receiving any input events.  But disabling a
     * lightweight container affects only this container.
     *
     * @param     b   If {@code true}, this component is
     *            enabled; otherwise this component is disabled
     * @see #isEnabled
     * @see #isLightweight
     * @since 1.1
     */
    public void setEnabled(boolean b) {
        enable(b);
    }

    
Deprecated:As of JDK version 1.1, replaced by setEnabled(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setEnabled(boolean)}.
     */
    @Deprecated
    public void enable() {
        if (!enabled) {
            synchronized (getTreeLock()) {
                enabled = true;
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.setEnabled(true);
                    if (visible && !getRecursivelyVisibleBounds().isEmpty()) {
                        updateCursorImmediately();
                    }
                }
            }
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                                                     AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                     null, AccessibleState.ENABLED);
            }
        }
    }

    
Enables or disables this component.

Params:
  • b – true to enable this component; otherwise false
Deprecated:As of JDK version 1.1, replaced by setEnabled(boolean).
/**
     * Enables or disables this component.
     *
     * @param  b {@code true} to enable this component;
     *         otherwise {@code false}
     *
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setEnabled(boolean)}.
     */
    @Deprecated
    public void enable(boolean b) {
        if (b) {
            enable();
        } else {
            disable();
        }
    }

    
Deprecated:As of JDK version 1.1, replaced by setEnabled(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setEnabled(boolean)}.
     */
    @Deprecated
    public void disable() {
        if (enabled) {
            KeyboardFocusManager.clearMostRecentFocusOwner(this);
            synchronized (getTreeLock()) {
                enabled = false;
                // A disabled lw container is allowed to contain a focus owner.
                if ((isFocusOwner() || (containsFocus() && !isLightweight())) &&
                    KeyboardFocusManager.isAutoFocusTransferEnabled())
                {
                    // Don't clear the global focus owner. If transferFocus
                    // fails, we want the focus to stay on the disabled
                    // Component so that keyboard traversal, et. al. still
                    // makes sense to the user.
                    transferFocus(false);
                }
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.setEnabled(false);
                    if (visible && !getRecursivelyVisibleBounds().isEmpty()) {
                        updateCursorImmediately();
                    }
                }
            }
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                                                     AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                     null, AccessibleState.ENABLED);
            }
        }
    }

    
Returns true if this component is painted to an offscreen image
("buffer") that's copied to the screen later.  Component
subclasses that support double buffering should override this
method to return true if double buffering is enabled.

Returns:false by default
/**
     * Returns true if this component is painted to an offscreen image
     * ("buffer") that's copied to the screen later.  Component
     * subclasses that support double buffering should override this
     * method to return true if double buffering is enabled.
     *
     * @return false by default
     */
    public boolean isDoubleBuffered() {
        return false;
    }

    
Enables or disables input method support for this component. If input
method support is enabled and the component also processes key events,
incoming events are offered to
the current input method and will only be processed by the component or
dispatched to its listeners if the input method does not consume them.
By default, input method support is enabled.

Params:
  • enable – true to enable, false to disable
See Also:
Since:1.2
/**
     * Enables or disables input method support for this component. If input
     * method support is enabled and the component also processes key events,
     * incoming events are offered to
     * the current input method and will only be processed by the component or
     * dispatched to its listeners if the input method does not consume them.
     * By default, input method support is enabled.
     *
     * @param enable true to enable, false to disable
     * @see #processKeyEvent
     * @since 1.2
     */
    public void enableInputMethods(boolean enable) {
        if (enable) {
            if ((eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0)
                return;

            // If this component already has focus, then activate the
            // input method by dispatching a synthesized focus gained
            // event.
            if (isFocusOwner()) {
                InputContext inputContext = getInputContext();
                if (inputContext != null) {
                    FocusEvent focusGainedEvent =
                        new FocusEvent(this, FocusEvent.FOCUS_GAINED);
                    inputContext.dispatchEvent(focusGainedEvent);
                }
            }

            eventMask |= AWTEvent.INPUT_METHODS_ENABLED_MASK;
        } else {
            if ((eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0) {
                InputContext inputContext = getInputContext();
                if (inputContext != null) {
                    inputContext.endComposition();
                    inputContext.removeNotify(this);
                }
            }
            eventMask &= ~AWTEvent.INPUT_METHODS_ENABLED_MASK;
        }
    }

    
Shows or hides this component depending on the value of parameter b. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • b –  if true, shows this component; otherwise, hides this component
See Also:
Since:1.1
/**
     * Shows or hides this component depending on the value of parameter
     * {@code b}.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param b  if {@code true}, shows this component;
     * otherwise, hides this component
     * @see #isVisible
     * @see #invalidate
     * @since 1.1
     */
    public void setVisible(boolean b) {
        show(b);
    }

    
Deprecated:As of JDK version 1.1, replaced by setVisible(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setVisible(boolean)}.
     */
    @Deprecated
    public void show() {
        if (!visible) {
            synchronized (getTreeLock()) {
                visible = true;
                mixOnShowing();
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.setVisible(true);
                    createHierarchyEvents(HierarchyEvent.HIERARCHY_CHANGED,
                                          this, parent,
                                          HierarchyEvent.SHOWING_CHANGED,
                                          Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK));
                    if (peer instanceof LightweightPeer) {
                        repaint();
                    }
                    updateCursorImmediately();
                }

                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 ||
                    Toolkit.enabledOnToolkit(AWTEvent.COMPONENT_EVENT_MASK)) {
                    ComponentEvent e = new ComponentEvent(this,
                                                          ComponentEvent.COMPONENT_SHOWN);
                    Toolkit.getEventQueue().postEvent(e);
                }
            }
            Container parent = this.parent;
            if (parent != null) {
                parent.invalidate();
            }
        }
    }

    
Makes this component visible or invisible.

Params:
  • b – true to make this component visible; otherwise false
Deprecated:As of JDK version 1.1, replaced by setVisible(boolean).
/**
     * Makes this component visible or invisible.
     *
     * @param  b {@code true} to make this component visible;
     *         otherwise {@code false}
     *
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setVisible(boolean)}.
     */
    @Deprecated
    public void show(boolean b) {
        if (b) {
            show();
        } else {
            hide();
        }
    }

    boolean containsFocus() {
        return isFocusOwner();
    }

    void clearMostRecentFocusOwnerOnHide() {
        KeyboardFocusManager.clearMostRecentFocusOwner(this);
    }

    void clearCurrentFocusCycleRootOnHide() {
        /* do nothing */
    }

    
Deprecated:As of JDK version 1.1, replaced by setVisible(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setVisible(boolean)}.
     */
    @Deprecated
    public void hide() {
        isPacked = false;

        if (visible) {
            clearCurrentFocusCycleRootOnHide();
            clearMostRecentFocusOwnerOnHide();
            synchronized (getTreeLock()) {
                visible = false;
                mixOnHiding(isLightweight());
                if (containsFocus() && KeyboardFocusManager.isAutoFocusTransferEnabled()) {
                    transferFocus(true);
                }
                ComponentPeer peer = this.peer;
                if (peer != null) {
                    peer.setVisible(false);
                    createHierarchyEvents(HierarchyEvent.HIERARCHY_CHANGED,
                                          this, parent,
                                          HierarchyEvent.SHOWING_CHANGED,
                                          Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK));
                    if (peer instanceof LightweightPeer) {
                        repaint();
                    }
                    updateCursorImmediately();
                }
                if (componentListener != null ||
                    (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 ||
                    Toolkit.enabledOnToolkit(AWTEvent.COMPONENT_EVENT_MASK)) {
                    ComponentEvent e = new ComponentEvent(this,
                                                          ComponentEvent.COMPONENT_HIDDEN);
                    Toolkit.getEventQueue().postEvent(e);
                }
            }
            Container parent = this.parent;
            if (parent != null) {
                parent.invalidate();
            }
        }
    }

    
Gets the foreground color of this component.

See Also:
Returns:this component's foreground color; if this component does
not have a foreground color, the foreground color of its parent
is returned
Since:1.0
/**
     * Gets the foreground color of this component.
     * @return this component's foreground color; if this component does
     * not have a foreground color, the foreground color of its parent
     * is returned
     * @see #setForeground
     * @since 1.0
     */
    @Transient
    public Color getForeground() {
        Color foreground = this.foreground;
        if (foreground != null) {
            return foreground;
        }
        Container parent = this.parent;
        return (parent != null) ? parent.getForeground() : null;
    }

    
Sets the foreground color of this component.

Params:
  • c – the color to become this component's foreground color; if this parameter is null then this component will inherit the foreground color of its parent
See Also:
Since:1.0
/**
     * Sets the foreground color of this component.
     * @param c the color to become this component's
     *          foreground color; if this parameter is {@code null}
     *          then this component will inherit
     *          the foreground color of its parent
     * @see #getForeground
     * @since 1.0
     */
    public void setForeground(Color c) {
        Color oldColor = foreground;
        ComponentPeer peer = this.peer;
        foreground = c;
        if (peer != null) {
            c = getForeground();
            if (c != null) {
                peer.setForeground(c);
            }
        }
        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("foreground", oldColor, c);
    }

    
Returns whether the foreground color has been explicitly set for this Component. If this method returns false, this Component is inheriting its foreground color from an ancestor. 
Returns:true if the foreground color has been explicitly set for this Component; false otherwise.
Since:1.4
/**
     * Returns whether the foreground color has been explicitly set for this
     * Component. If this method returns {@code false}, this Component is
     * inheriting its foreground color from an ancestor.
     *
     * @return {@code true} if the foreground color has been explicitly
     *         set for this Component; {@code false} otherwise.
     * @since 1.4
     */
    public boolean isForegroundSet() {
        return (foreground != null);
    }

    
Gets the background color of this component.

See Also:
Returns:this component's background color; if this component does
         not have a background color,
         the background color of its parent is returned
Since:1.0
/**
     * Gets the background color of this component.
     * @return this component's background color; if this component does
     *          not have a background color,
     *          the background color of its parent is returned
     * @see #setBackground
     * @since 1.0
     */
    @Transient
    public Color getBackground() {
        Color background = this.background;
        if (background != null) {
            return background;
        }
        Container parent = this.parent;
        return (parent != null) ? parent.getBackground() : null;
    }

    
Sets the background color of this component.


The background color affects each component differently and the
parts of the component that are affected by the background color
may differ between operating systems.

Params:
  • c – the color to become this component's color; if this parameter is null, then this component will inherit the background color of its parent
See Also:
Since:1.0
/**
     * Sets the background color of this component.
     * <p>
     * The background color affects each component differently and the
     * parts of the component that are affected by the background color
     * may differ between operating systems.
     *
     * @param c the color to become this component's color;
     *          if this parameter is {@code null}, then this
     *          component will inherit the background color of its parent
     * @see #getBackground
     * @since 1.0
     */
    public void setBackground(Color c) {
        Color oldColor = background;
        ComponentPeer peer = this.peer;
        background = c;
        if (peer != null) {
            c = getBackground();
            if (c != null) {
                peer.setBackground(c);
            }
        }
        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("background", oldColor, c);
    }

    
Returns whether the background color has been explicitly set for this Component. If this method returns false, this Component is inheriting its background color from an ancestor. 
Returns:true if the background color has been explicitly set for this Component; false otherwise.
Since:1.4
/**
     * Returns whether the background color has been explicitly set for this
     * Component. If this method returns {@code false}, this Component is
     * inheriting its background color from an ancestor.
     *
     * @return {@code true} if the background color has been explicitly
     *         set for this Component; {@code false} otherwise.
     * @since 1.4
     */
    public boolean isBackgroundSet() {
        return (background != null);
    }

    
Gets the font of this component.

See Also:
Returns:this component's font; if a font has not been set
for this component, the font of its parent is returned
Since:1.0
/**
     * Gets the font of this component.
     * @return this component's font; if a font has not been set
     * for this component, the font of its parent is returned
     * @see #setFont
     * @since 1.0
     */
    @Transient
    public Font getFont() {
        return getFont_NoClientCode();
    }

    // NOTE: This method may be called by privileged threads.
    //       This functionality is implemented in a package-private method
    //       to insure that it cannot be overridden by client subclasses.
    //       DO NOT INVOKE CLIENT CODE ON THIS THREAD!
    final Font getFont_NoClientCode() {
        Font font = this.font;
        if (font != null) {
            return font;
        }
        Container parent = this.parent;
        return (parent != null) ? parent.getFont_NoClientCode() : null;
    }

    
Sets the font of this component.


This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • f – the font to become this component's font; if this parameter is null then this component will inherit the font of its parent
See Also:
Since:1.0
/**
     * Sets the font of this component.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param f the font to become this component's font;
     *          if this parameter is {@code null} then this
     *          component will inherit the font of its parent
     * @see #getFont
     * @see #invalidate
     * @since 1.0
     */
    public void setFont(Font f) {
        Font oldFont, newFont;
        synchronized(getTreeLock()) {
            oldFont = font;
            newFont = font = f;
            ComponentPeer peer = this.peer;
            if (peer != null) {
                f = getFont();
                if (f != null) {
                    peer.setFont(f);
                    peerFont = f;
                }
            }
        }
        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("font", oldFont, newFont);

        // This could change the preferred size of the Component.
        // Fix for 6213660. Should compare old and new fonts and do not
        // call invalidate() if they are equal.
        if (f != oldFont && (oldFont == null ||
                                      !oldFont.equals(f))) {
            invalidateIfValid();
        }
    }

    
Returns whether the font has been explicitly set for this Component. If this method returns false, this Component is inheriting its font from an ancestor. 
Returns:true if the font has been explicitly set for this Component; false otherwise.
Since:1.4
/**
     * Returns whether the font has been explicitly set for this Component. If
     * this method returns {@code false}, this Component is inheriting its
     * font from an ancestor.
     *
     * @return {@code true} if the font has been explicitly set for this
     *         Component; {@code false} otherwise.
     * @since 1.4
     */
    public boolean isFontSet() {
        return (font != null);
    }

    
Gets the locale of this component.

Throws:
  • IllegalComponentStateException – if the Component does not have its own locale and has not yet been added to a containment hierarchy such that the locale can be determined from the containing parent
See Also:
Returns:this component's locale; if this component does not
         have a locale, the locale of its parent is returned
Since: 1.1
/**
     * Gets the locale of this component.
     * @return this component's locale; if this component does not
     *          have a locale, the locale of its parent is returned
     * @see #setLocale
     * @exception IllegalComponentStateException if the {@code Component}
     *          does not have its own locale and has not yet been added to
     *          a containment hierarchy such that the locale can be determined
     *          from the containing parent
     * @since  1.1
     */
    public Locale getLocale() {
        Locale locale = this.locale;
        if (locale != null) {
            return locale;
        }
        Container parent = this.parent;

        if (parent == null) {
            throw new IllegalComponentStateException("This component must have a parent in order to determine its locale");
        } else {
            return parent.getLocale();
        }
    }

    
Sets the locale of this component.  This is a bound property.


This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • l – the locale to become this component's locale
See Also:
Since:1.1
/**
     * Sets the locale of this component.  This is a bound property.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param l the locale to become this component's locale
     * @see #getLocale
     * @see #invalidate
     * @since 1.1
     */
    public void setLocale(Locale l) {
        Locale oldValue = locale;
        locale = l;

        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("locale", oldValue, l);

        // This could change the preferred size of the Component.
        invalidateIfValid();
    }

    
Gets the instance of ColorModel used to display the component on the output device. 
See Also:
Returns:the color model used by this component
Since:1.0
/**
     * Gets the instance of {@code ColorModel} used to display
     * the component on the output device.
     * @return the color model used by this component
     * @see java.awt.image.ColorModel
     * @see java.awt.peer.ComponentPeer#getColorModel()
     * @see Toolkit#getColorModel()
     * @since 1.0
     */
    public ColorModel getColorModel() {
        ComponentPeer peer = this.peer;
        if ((peer != null) && ! (peer instanceof LightweightPeer)) {
            return peer.getColorModel();
        } else if (GraphicsEnvironment.isHeadless()) {
            return ColorModel.getRGBdefault();
        } // else
        return getToolkit().getColorModel();
    }

    
Gets the location of this component in the form of a
point specifying the component's top-left corner.
The location will be relative to the parent's coordinate space.

 Due to the asynchronous nature of native event handling, this method can return outdated values (for instance, after several calls of setLocation() in rapid succession). For this reason, the recommended method of obtaining a component's position is within java.awt.event.ComponentListener.componentMoved(), which is called after the operating system has finished moving the component. 


See Also:
Returns:an instance of Point representing the top-left corner of the component's bounds in the coordinate space of the component's parent
Since:1.1
/**
     * Gets the location of this component in the form of a
     * point specifying the component's top-left corner.
     * The location will be relative to the parent's coordinate space.
     * <p>
     * Due to the asynchronous nature of native event handling, this
     * method can return outdated values (for instance, after several calls
     * of {@code setLocation()} in rapid succession).  For this
     * reason, the recommended method of obtaining a component's position is
     * within {@code java.awt.event.ComponentListener.componentMoved()},
     * which is called after the operating system has finished moving the
     * component.
     * </p>
     * @return an instance of {@code Point} representing
     *          the top-left corner of the component's bounds in
     *          the coordinate space of the component's parent
     * @see #setLocation
     * @see #getLocationOnScreen
     * @since 1.1
     */
    public Point getLocation() {
        return location();
    }

    
Gets the location of this component in the form of a point
specifying the component's top-left corner in the screen's
coordinate space.

Throws:
See Also:
Returns:an instance of Point representing the top-left corner of the component's bounds in the coordinate space of the screen
/**
     * Gets the location of this component in the form of a point
     * specifying the component's top-left corner in the screen's
     * coordinate space.
     * @return an instance of {@code Point} representing
     *          the top-left corner of the component's bounds in the
     *          coordinate space of the screen
     * @throws IllegalComponentStateException if the
     *          component is not showing on the screen
     * @see #setLocation
     * @see #getLocation
     */
    public Point getLocationOnScreen() {
        synchronized (getTreeLock()) {
            return getLocationOnScreen_NoTreeLock();
        }
    }

    /*
     * a package private version of getLocationOnScreen
     * used by GlobalCursormanager to update cursor
     */
    final Point getLocationOnScreen_NoTreeLock() {
        ComponentPeer peer = this.peer;
        if (peer != null && isShowing()) {
            if (peer instanceof LightweightPeer) {
                // lightweight component location needs to be translated
                // relative to a native component.
                Container host = getNativeContainer();
                Point pt = host.peer.getLocationOnScreen();
                for(Component c = this; c != host; c = c.getContainer()) {
                    pt.x += c.x;
                    pt.y += c.y;
                }
                return pt;
            } else {
                Point pt = peer.getLocationOnScreen();
                return pt;
            }
        } else {
            throw new IllegalComponentStateException("component must be showing on the screen to determine its location");
        }
    }


    
Returns the location of this component's top left corner.

Returns:the location of this component's top left corner
Deprecated:As of JDK version 1.1, replaced by getLocation().
/**
     * Returns the location of this component's top left corner.
     *
     * @return the location of this component's top left corner
     * @deprecated As of JDK version 1.1,
     * replaced by {@code getLocation()}.
     */
    @Deprecated
    public Point location() {
        return location_NoClientCode();
    }

    private Point location_NoClientCode() {
        return new Point(x, y);
    }

    
Moves this component to a new location. The top-left corner of the new location is specified by the x and y parameters in the coordinate space of this component's parent. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • x – the x-coordinate of the new location's
         top-left corner in the parent's coordinate space
  • y – the y-coordinate of the new location's
         top-left corner in the parent's coordinate space
See Also:
Since:1.1
/**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by the {@code x} and {@code y}
     * parameters in the coordinate space of this component's parent.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param x the <i>x</i>-coordinate of the new location's
     *          top-left corner in the parent's coordinate space
     * @param y the <i>y</i>-coordinate of the new location's
     *          top-left corner in the parent's coordinate space
     * @see #getLocation
     * @see #setBounds
     * @see #invalidate
     * @since 1.1
     */
    public void setLocation(int x, int y) {
        move(x, y);
    }

    
Moves this component to a new location.

Params:
  • x – the x-coordinate of the new location's
          top-left corner in the parent's coordinate space
  • y – the y-coordinate of the new location's
          top-left corner in the parent's coordinate space
Deprecated:As of JDK version 1.1, replaced by setLocation(int, int).
/**
     * Moves this component to a new location.
     *
     * @param  x the <i>x</i>-coordinate of the new location's
     *           top-left corner in the parent's coordinate space
     * @param  y the <i>y</i>-coordinate of the new location's
     *           top-left corner in the parent's coordinate space
     *
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setLocation(int, int)}.
     */
    @Deprecated
    public void move(int x, int y) {
        synchronized(getTreeLock()) {
            setBoundsOp(ComponentPeer.SET_LOCATION);
            setBounds(x, y, width, height);
        }
    }

    
Moves this component to a new location. The top-left corner of the new location is specified by point p. Point p is given in the parent's coordinate space. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • p – the point defining the top-left corner
         of the new location, given in the coordinate space of this
         component's parent
See Also:
Since:1.1
/**
     * Moves this component to a new location. The top-left corner of
     * the new location is specified by point {@code p}. Point
     * {@code p} is given in the parent's coordinate space.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param p the point defining the top-left corner
     *          of the new location, given in the coordinate space of this
     *          component's parent
     * @see #getLocation
     * @see #setBounds
     * @see #invalidate
     * @since 1.1
     */
    public void setLocation(Point p) {
        setLocation(p.x, p.y);
    }

    
Returns the size of this component in the form of a Dimension object. The height field of the Dimension object contains this component's height, and the width field of the Dimension object contains this component's width. 
See Also:
Returns:a Dimension object that indicates the size of this component
Since:1.1
/**
     * Returns the size of this component in the form of a
     * {@code Dimension} object. The {@code height}
     * field of the {@code Dimension} object contains
     * this component's height, and the {@code width}
     * field of the {@code Dimension} object contains
     * this component's width.
     * @return a {@code Dimension} object that indicates the
     *          size of this component
     * @see #setSize
     * @since 1.1
     */
    public Dimension getSize() {
        return size();
    }

    
Returns the size of this component in the form of a Dimension object. 
Returns:the Dimension object that indicates the size of this component
Deprecated:As of JDK version 1.1, replaced by getSize().
/**
     * Returns the size of this component in the form of a
     * {@code Dimension} object.
     *
     * @return the {@code Dimension} object that indicates the
     *         size of this component
     * @deprecated As of JDK version 1.1,
     * replaced by {@code getSize()}.
     */
    @Deprecated
    public Dimension size() {
        return new Dimension(width, height);
    }

    
Resizes this component so that it has width width and height height. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • width – the new width of this component in pixels
  • height – the new height of this component in pixels
See Also:
Since:1.1
/**
     * Resizes this component so that it has width {@code width}
     * and height {@code height}.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param width the new width of this component in pixels
     * @param height the new height of this component in pixels
     * @see #getSize
     * @see #setBounds
     * @see #invalidate
     * @since 1.1
     */
    public void setSize(int width, int height) {
        resize(width, height);
    }

    
Resizes this component.

Params:
  • width – the new width of the component
  • height – the new height of the component
Deprecated:As of JDK version 1.1, replaced by setSize(int, int).
/**
     * Resizes this component.
     *
     * @param  width the new width of the component
     * @param  height the new height of the component
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setSize(int, int)}.
     */
    @Deprecated
    public void resize(int width, int height) {
        synchronized(getTreeLock()) {
            setBoundsOp(ComponentPeer.SET_SIZE);
            setBounds(x, y, width, height);
        }
    }

    
Resizes this component so that it has width d.width and height d.height. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • d – the dimension specifying the new size
         of this component
Throws:
See Also:
Since:1.1
/**
     * Resizes this component so that it has width {@code d.width}
     * and height {@code d.height}.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param d the dimension specifying the new size
     *          of this component
     * @throws NullPointerException if {@code d} is {@code null}
     * @see #setSize
     * @see #setBounds
     * @see #invalidate
     * @since 1.1
     */
    public void setSize(Dimension d) {
        resize(d);
    }

    
Resizes this component so that it has width d.width and height d.height. 
Params:
  • d – the new size of this component
Deprecated:As of JDK version 1.1, replaced by setSize(Dimension).
/**
     * Resizes this component so that it has width {@code d.width}
     * and height {@code d.height}.
     *
     * @param  d the new size of this component
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setSize(Dimension)}.
     */
    @Deprecated
    public void resize(Dimension d) {
        setSize(d.width, d.height);
    }

    
Gets the bounds of this component in the form of a Rectangle object. The bounds specify this component's width, height, and location relative to its parent. 
See Also:
Returns:a rectangle indicating this component's bounds
/**
     * Gets the bounds of this component in the form of a
     * {@code Rectangle} object. The bounds specify this
     * component's width, height, and location relative to
     * its parent.
     * @return a rectangle indicating this component's bounds
     * @see #setBounds
     * @see #getLocation
     * @see #getSize
     */
    public Rectangle getBounds() {
        return bounds();
    }

    
Returns the bounding rectangle of this component.

Returns:the bounding rectangle for this component
Deprecated:As of JDK version 1.1, replaced by getBounds().
/**
     * Returns the bounding rectangle of this component.
     *
     * @return the bounding rectangle for this component
     * @deprecated As of JDK version 1.1,
     * replaced by {@code getBounds()}.
     */
    @Deprecated
    public Rectangle bounds() {
        return new Rectangle(x, y, width, height);
    }

    
Moves and resizes this component. The new location of the top-left corner is specified by x and y, and the new size is specified by width and height. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • x – the new x-coordinate of this component
  • y – the new y-coordinate of this component
  • width – the new width of this component
  • height – the new height of this component
See Also:
Since:1.1
/**
     * Moves and resizes this component. The new location of the top-left
     * corner is specified by {@code x} and {@code y}, and the
     * new size is specified by {@code width} and {@code height}.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param x the new <i>x</i>-coordinate of this component
     * @param y the new <i>y</i>-coordinate of this component
     * @param width the new {@code width} of this component
     * @param height the new {@code height} of this
     *          component
     * @see #getBounds
     * @see #setLocation(int, int)
     * @see #setLocation(Point)
     * @see #setSize(int, int)
     * @see #setSize(Dimension)
     * @see #invalidate
     * @since 1.1
     */
    public void setBounds(int x, int y, int width, int height) {
        reshape(x, y, width, height);
    }

    
Reshapes the bounding rectangle for this component.

Params:
  • x – the x coordinate of the upper left corner of the rectangle
  • y – the y coordinate of the upper left corner of the rectangle
  • width – the width of the rectangle
  • height – the height of the rectangle
Deprecated:As of JDK version 1.1, replaced by setBounds(int, int, int, int).
/**
     * Reshapes the bounding rectangle for this component.
     *
     * @param  x the <i>x</i> coordinate of the upper left corner of the rectangle
     * @param  y the <i>y</i> coordinate of the upper left corner of the rectangle
     * @param  width the width of the rectangle
     * @param  height the height of the rectangle
     *
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setBounds(int, int, int, int)}.
     */
    @Deprecated
    public void reshape(int x, int y, int width, int height) {
        synchronized (getTreeLock()) {
            try {
                setBoundsOp(ComponentPeer.SET_BOUNDS);
                boolean resized = (this.width != width) || (this.height != height);
                boolean moved = (this.x != x) || (this.y != y);
                if (!resized && !moved) {
                    return;
                }
                int oldX = this.x;
                int oldY = this.y;
                int oldWidth = this.width;
                int oldHeight = this.height;
                this.x = x;
                this.y = y;
                this.width = width;
                this.height = height;

                if (resized) {
                    isPacked = false;
                }

                boolean needNotify = true;
                mixOnReshaping();
                if (peer != null) {
                    // LightweightPeer is an empty stub so can skip peer.reshape
                    if (!(peer instanceof LightweightPeer)) {
                        reshapeNativePeer(x, y, width, height, getBoundsOp());
                        // Check peer actually changed coordinates
                        resized = (oldWidth != this.width) || (oldHeight != this.height);
                        moved = (oldX != this.x) || (oldY != this.y);
                        // fix for 5025858: do not send ComponentEvents for toplevel
                        // windows here as it is done from peer or native code when
                        // the window is really resized or moved, otherwise some
                        // events may be sent twice
                        if (this instanceof Window) {
                            needNotify = false;
                        }
                    }
                    if (resized) {
                        invalidate();
                    }
                    if (parent != null) {
                        parent.invalidateIfValid();
                    }
                }
                if (needNotify) {
                    notifyNewBounds(resized, moved);
                }
                repaintParentIfNeeded(oldX, oldY, oldWidth, oldHeight);
            } finally {
                setBoundsOp(ComponentPeer.RESET_OPERATION);
            }
        }
    }

    private void repaintParentIfNeeded(int oldX, int oldY, int oldWidth,
                                       int oldHeight)
    {
        if (parent != null && peer instanceof LightweightPeer && isShowing()) {
            // Have the parent redraw the area this component occupied.
            parent.repaint(oldX, oldY, oldWidth, oldHeight);
            // Have the parent redraw the area this component *now* occupies.
            repaint();
        }
    }

    private void reshapeNativePeer(int x, int y, int width, int height, int op) {
        // native peer might be offset by more than direct
        // parent since parent might be lightweight.
        int nativeX = x;
        int nativeY = y;
        for (Component c = parent;
             (c != null) && (c.peer instanceof LightweightPeer);
             c = c.parent)
        {
            nativeX += c.x;
            nativeY += c.y;
        }
        peer.setBounds(nativeX, nativeY, width, height, op);
    }

    @SuppressWarnings("deprecation")
    private void notifyNewBounds(boolean resized, boolean moved) {
        if (componentListener != null
            || (eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0
            || Toolkit.enabledOnToolkit(AWTEvent.COMPONENT_EVENT_MASK))
            {
                if (resized) {
                    ComponentEvent e = new ComponentEvent(this,
                                                          ComponentEvent.COMPONENT_RESIZED);
                    Toolkit.getEventQueue().postEvent(e);
                }
                if (moved) {
                    ComponentEvent e = new ComponentEvent(this,
                                                          ComponentEvent.COMPONENT_MOVED);
                    Toolkit.getEventQueue().postEvent(e);
                }
            } else {
                if (this instanceof Container && ((Container)this).countComponents() > 0) {
                    boolean enabledOnToolkit =
                        Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK);
                    if (resized) {

                        ((Container)this).createChildHierarchyEvents(
                                                                     HierarchyEvent.ANCESTOR_RESIZED, 0, enabledOnToolkit);
                    }
                    if (moved) {
                        ((Container)this).createChildHierarchyEvents(
                                                                     HierarchyEvent.ANCESTOR_MOVED, 0, enabledOnToolkit);
                    }
                }
                }
    }

    
Moves and resizes this component to conform to the new bounding rectangle r. This component's new position is specified by r.x and r.y, and its new size is specified by r.width and r.height 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • r – the new bounding rectangle for this component
Throws:
See Also:
Since:    1.1
/**
     * Moves and resizes this component to conform to the new
     * bounding rectangle {@code r}. This component's new
     * position is specified by {@code r.x} and {@code r.y},
     * and its new size is specified by {@code r.width} and
     * {@code r.height}
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param r the new bounding rectangle for this component
     * @throws NullPointerException if {@code r} is {@code null}
     * @see       #getBounds
     * @see       #setLocation(int, int)
     * @see       #setLocation(Point)
     * @see       #setSize(int, int)
     * @see       #setSize(Dimension)
     * @see #invalidate
     * @since     1.1
     */
    public void setBounds(Rectangle r) {
        setBounds(r.x, r.y, r.width, r.height);
    }


    
Returns the current x coordinate of the components origin. This method is preferable to writing component.getBounds().x, or component.getLocation().x because it doesn't cause any heap allocations. 
Returns:the current x coordinate of the components origin
Since:1.2
/**
     * Returns the current x coordinate of the components origin.
     * This method is preferable to writing
     * {@code component.getBounds().x},
     * or {@code component.getLocation().x} because it doesn't
     * cause any heap allocations.
     *
     * @return the current x coordinate of the components origin
     * @since 1.2
     */
    public int getX() {
        return x;
    }


    
Returns the current y coordinate of the components origin. This method is preferable to writing component.getBounds().y, or component.getLocation().y because it doesn't cause any heap allocations. 
Returns:the current y coordinate of the components origin
Since:1.2
/**
     * Returns the current y coordinate of the components origin.
     * This method is preferable to writing
     * {@code component.getBounds().y},
     * or {@code component.getLocation().y} because it
     * doesn't cause any heap allocations.
     *
     * @return the current y coordinate of the components origin
     * @since 1.2
     */
    public int getY() {
        return y;
    }


    
Returns the current width of this component. This method is preferable to writing component.getBounds().width, or component.getSize().width because it doesn't cause any heap allocations. 
Returns:the current width of this component
Since:1.2
/**
     * Returns the current width of this component.
     * This method is preferable to writing
     * {@code component.getBounds().width},
     * or {@code component.getSize().width} because it
     * doesn't cause any heap allocations.
     *
     * @return the current width of this component
     * @since 1.2
     */
    public int getWidth() {
        return width;
    }


    
Returns the current height of this component. This method is preferable to writing component.getBounds().height, or component.getSize().height because it doesn't cause any heap allocations. 
Returns:the current height of this component
Since:1.2
/**
     * Returns the current height of this component.
     * This method is preferable to writing
     * {@code component.getBounds().height},
     * or {@code component.getSize().height} because it
     * doesn't cause any heap allocations.
     *
     * @return the current height of this component
     * @since 1.2
     */
    public int getHeight() {
        return height;
    }

    
Stores the bounds of this component into "return value" rv and
return rv. If rv is null a new Rectangle is allocated. This version of getBounds is useful if the caller wants to avoid allocating a new Rectangle object on the heap. 
Params:
  • rv – the return value, modified to the components bounds
Returns:rv
/**
     * Stores the bounds of this component into "return value" <b>rv</b> and
     * return <b>rv</b>.  If rv is {@code null} a new
     * {@code Rectangle} is allocated.
     * This version of {@code getBounds} is useful if the caller
     * wants to avoid allocating a new {@code Rectangle} object
     * on the heap.
     *
     * @param rv the return value, modified to the components bounds
     * @return rv
     */
    public Rectangle getBounds(Rectangle rv) {
        if (rv == null) {
            return new Rectangle(getX(), getY(), getWidth(), getHeight());
        }
        else {
            rv.setBounds(getX(), getY(), getWidth(), getHeight());
            return rv;
        }
    }

    
Stores the width/height of this component into "return value" rv
and return rv. If rv is null a new Dimension object is allocated. This version of getSize is useful if the caller wants to avoid allocating a new Dimension object on the heap. 
Params:
  • rv – the return value, modified to the components size
Returns:rv
/**
     * Stores the width/height of this component into "return value" <b>rv</b>
     * and return <b>rv</b>.   If rv is {@code null} a new
     * {@code Dimension} object is allocated.  This version of
     * {@code getSize} is useful if the caller wants to avoid
     * allocating a new {@code Dimension} object on the heap.
     *
     * @param rv the return value, modified to the components size
     * @return rv
     */
    public Dimension getSize(Dimension rv) {
        if (rv == null) {
            return new Dimension(getWidth(), getHeight());
        }
        else {
            rv.setSize(getWidth(), getHeight());
            return rv;
        }
    }

    
Stores the x,y origin of this component into "return value" rv
and return rv. If rv is null a new Point is allocated. This version of getLocation is useful if the caller wants to avoid allocating a new Point object on the heap. 
Params:
  • rv – the return value, modified to the components location
Returns:rv
/**
     * Stores the x,y origin of this component into "return value" <b>rv</b>
     * and return <b>rv</b>.   If rv is {@code null} a new
     * {@code Point} is allocated.
     * This version of {@code getLocation} is useful if the
     * caller wants to avoid allocating a new {@code Point}
     * object on the heap.
     *
     * @param rv the return value, modified to the components location
     * @return rv
     */
    public Point getLocation(Point rv) {
        if (rv == null) {
            return new Point(getX(), getY());
        }
        else {
            rv.setLocation(getX(), getY());
            return rv;
        }
    }

    
Returns true if this component is completely opaque, returns
false by default.


An opaque component paints every pixel within its
rectangular region. A non-opaque component paints only some of
its pixels, allowing the pixels underneath it to "show through".
A component that does not fully paint its pixels therefore
provides a degree of transparency.


Subclasses that guarantee to always completely paint their
contents should override this method and return true.

See Also:
Returns:true if this component is completely opaque
Since:1.2
/**
     * Returns true if this component is completely opaque, returns
     * false by default.
     * <p>
     * An opaque component paints every pixel within its
     * rectangular region. A non-opaque component paints only some of
     * its pixels, allowing the pixels underneath it to "show through".
     * A component that does not fully paint its pixels therefore
     * provides a degree of transparency.
     * <p>
     * Subclasses that guarantee to always completely paint their
     * contents should override this method and return true.
     *
     * @return true if this component is completely opaque
     * @see #isLightweight
     * @since 1.2
     */
    public boolean isOpaque() {
        if (peer == null) {
            return false;
        }
        else {
            return !isLightweight();
        }
    }


    
A lightweight component doesn't have a native toolkit peer. Subclasses of Component and Container, other than the ones defined in this package like Button or Scrollbar, are lightweight. All of the Swing components are lightweights. 
 This method will always return false if this component is not displayable because it is impossible to determine the weight of an undisplayable component. 
See Also:
Returns:true if this component has a lightweight peer; false if
        it has a native peer or no peer
Since:1.2
/**
     * A lightweight component doesn't have a native toolkit peer.
     * Subclasses of {@code Component} and {@code Container},
     * other than the ones defined in this package like {@code Button}
     * or {@code Scrollbar}, are lightweight.
     * All of the Swing components are lightweights.
     * <p>
     * This method will always return {@code false} if this component
     * is not displayable because it is impossible to determine the
     * weight of an undisplayable component.
     *
     * @return true if this component has a lightweight peer; false if
     *         it has a native peer or no peer
     * @see #isDisplayable
     * @since 1.2
     */
    public boolean isLightweight() {
        return peer instanceof LightweightPeer;
    }


    
Sets the preferred size of this component to a constant value. Subsequent calls to getPreferredSize will always return this value. Setting the preferred size to null restores the default behavior. 
Params:
  • preferredSize – The new preferred size, or null
See Also:
Since:1.5
/**
     * Sets the preferred size of this component to a constant
     * value.  Subsequent calls to {@code getPreferredSize} will always
     * return this value.  Setting the preferred size to {@code null}
     * restores the default behavior.
     *
     * @param preferredSize The new preferred size, or null
     * @see #getPreferredSize
     * @see #isPreferredSizeSet
     * @since 1.5
     */
    public void setPreferredSize(Dimension preferredSize) {
        Dimension old;
        // If the preferred size was set, use it as the old value, otherwise
        // use null to indicate we didn't previously have a set preferred
        // size.
        if (prefSizeSet) {
            old = this.prefSize;
        }
        else {
            old = null;
        }
        this.prefSize = preferredSize;
        prefSizeSet = (preferredSize != null);
        firePropertyChange("preferredSize", old, preferredSize);
    }


    
Returns true if the preferred size has been set to a non-null value otherwise returns false. 
Returns:true if setPreferredSize has been invoked with a non-null value.
Since:1.5
/**
     * Returns true if the preferred size has been set to a
     * non-{@code null} value otherwise returns false.
     *
     * @return true if {@code setPreferredSize} has been invoked
     *         with a non-null value.
     * @since 1.5
     */
    public boolean isPreferredSizeSet() {
        return prefSizeSet;
    }


    
Gets the preferred size of this component.

See Also:
Returns:a dimension object indicating this component's preferred size
/**
     * Gets the preferred size of this component.
     * @return a dimension object indicating this component's preferred size
     * @see #getMinimumSize
     * @see LayoutManager
     */
    public Dimension getPreferredSize() {
        return preferredSize();
    }


    
Returns the component's preferred size.

Returns:the component's preferred size
Deprecated:As of JDK version 1.1, replaced by getPreferredSize().
/**
     * Returns the component's preferred size.
     *
     * @return the component's preferred size
     * @deprecated As of JDK version 1.1,
     * replaced by {@code getPreferredSize()}.
     */
    @Deprecated
    public Dimension preferredSize() {
        /* Avoid grabbing the lock if a reasonable cached size value
         * is available.
         */
        Dimension dim = prefSize;
        if (dim == null || !(isPreferredSizeSet() || isValid())) {
            synchronized (getTreeLock()) {
                prefSize = (peer != null) ?
                    peer.getPreferredSize() :
                    getMinimumSize();
                dim = prefSize;
            }
        }
        return new Dimension(dim);
    }

    
Sets the minimum size of this component to a constant value. Subsequent calls to getMinimumSize will always return this value. Setting the minimum size to null restores the default behavior. 
Params:
  • minimumSize – the new minimum size of this component
See Also:
Since:1.5
/**
     * Sets the minimum size of this component to a constant
     * value.  Subsequent calls to {@code getMinimumSize} will always
     * return this value.  Setting the minimum size to {@code null}
     * restores the default behavior.
     *
     * @param minimumSize the new minimum size of this component
     * @see #getMinimumSize
     * @see #isMinimumSizeSet
     * @since 1.5
     */
    public void setMinimumSize(Dimension minimumSize) {
        Dimension old;
        // If the minimum size was set, use it as the old value, otherwise
        // use null to indicate we didn't previously have a set minimum
        // size.
        if (minSizeSet) {
            old = this.minSize;
        }
        else {
            old = null;
        }
        this.minSize = minimumSize;
        minSizeSet = (minimumSize != null);
        firePropertyChange("minimumSize", old, minimumSize);
    }

    
Returns whether or not setMinimumSize has been invoked with a non-null value. 
Returns:true if setMinimumSize has been invoked with a non-null value.
Since:1.5
/**
     * Returns whether or not {@code setMinimumSize} has been
     * invoked with a non-null value.
     *
     * @return true if {@code setMinimumSize} has been invoked with a
     *              non-null value.
     * @since 1.5
     */
    public boolean isMinimumSizeSet() {
        return minSizeSet;
    }

    
Gets the minimum size of this component.

See Also:
Returns:a dimension object indicating this component's minimum size
/**
     * Gets the minimum size of this component.
     * @return a dimension object indicating this component's minimum size
     * @see #getPreferredSize
     * @see LayoutManager
     */
    public Dimension getMinimumSize() {
        return minimumSize();
    }

    
Returns the minimum size of this component.

Returns:the minimum size of this component
Deprecated:As of JDK version 1.1, replaced by getMinimumSize().
/**
     * Returns the minimum size of this component.
     *
     * @return the minimum size of this component
     * @deprecated As of JDK version 1.1,
     * replaced by {@code getMinimumSize()}.
     */
    @Deprecated
    public Dimension minimumSize() {
        /* Avoid grabbing the lock if a reasonable cached size value
         * is available.
         */
        Dimension dim = minSize;
        if (dim == null || !(isMinimumSizeSet() || isValid())) {
            synchronized (getTreeLock()) {
                minSize = (peer != null) ?
                    peer.getMinimumSize() :
                    size();
                dim = minSize;
            }
        }
        return new Dimension(dim);
    }

    
Sets the maximum size of this component to a constant value. Subsequent calls to getMaximumSize will always return this value. Setting the maximum size to null restores the default behavior. 
Params:
  • maximumSize – a Dimension containing the desired maximum allowable size
See Also:
Since:1.5
/**
     * Sets the maximum size of this component to a constant
     * value.  Subsequent calls to {@code getMaximumSize} will always
     * return this value.  Setting the maximum size to {@code null}
     * restores the default behavior.
     *
     * @param maximumSize a {@code Dimension} containing the
     *          desired maximum allowable size
     * @see #getMaximumSize
     * @see #isMaximumSizeSet
     * @since 1.5
     */
    public void setMaximumSize(Dimension maximumSize) {
        // If the maximum size was set, use it as the old value, otherwise
        // use null to indicate we didn't previously have a set maximum
        // size.
        Dimension old;
        if (maxSizeSet) {
            old = this.maxSize;
        }
        else {
            old = null;
        }
        this.maxSize = maximumSize;
        maxSizeSet = (maximumSize != null);
        firePropertyChange("maximumSize", old, maximumSize);
    }

    
Returns true if the maximum size has been set to a non-null value otherwise returns false. 
Returns:true if maximumSize is non-null, false otherwise
Since:1.5
/**
     * Returns true if the maximum size has been set to a non-{@code null}
     * value otherwise returns false.
     *
     * @return true if {@code maximumSize} is non-{@code null},
     *          false otherwise
     * @since 1.5
     */
    public boolean isMaximumSizeSet() {
        return maxSizeSet;
    }

    
Gets the maximum size of this component.

See Also:
Returns:a dimension object indicating this component's maximum size
/**
     * Gets the maximum size of this component.
     * @return a dimension object indicating this component's maximum size
     * @see #getMinimumSize
     * @see #getPreferredSize
     * @see LayoutManager
     */
    public Dimension getMaximumSize() {
        if (isMaximumSizeSet()) {
            return new Dimension(maxSize);
        }
        return new Dimension(Short.MAX_VALUE, Short.MAX_VALUE);
    }

    
Returns the alignment along the x axis.  This specifies how
the component would like to be aligned relative to other
components.  The value should be a number between 0 and 1
where 0 represents alignment along the origin, 1 is aligned
the furthest away from the origin, 0.5 is centered, etc.

Returns:the horizontal alignment of this component
/**
     * Returns the alignment along the x axis.  This specifies how
     * the component would like to be aligned relative to other
     * components.  The value should be a number between 0 and 1
     * where 0 represents alignment along the origin, 1 is aligned
     * the furthest away from the origin, 0.5 is centered, etc.
     *
     * @return the horizontal alignment of this component
     */
    public float getAlignmentX() {
        return CENTER_ALIGNMENT;
    }

    
Returns the alignment along the y axis.  This specifies how
the component would like to be aligned relative to other
components.  The value should be a number between 0 and 1
where 0 represents alignment along the origin, 1 is aligned
the furthest away from the origin, 0.5 is centered, etc.

Returns:the vertical alignment of this component
/**
     * Returns the alignment along the y axis.  This specifies how
     * the component would like to be aligned relative to other
     * components.  The value should be a number between 0 and 1
     * where 0 represents alignment along the origin, 1 is aligned
     * the furthest away from the origin, 0.5 is centered, etc.
     *
     * @return the vertical alignment of this component
     */
    public float getAlignmentY() {
        return CENTER_ALIGNMENT;
    }

    
Returns the baseline. The baseline is measured from the top of the component. This method is primarily meant for LayoutManagers to align components along their baseline. A return value less than 0 indicates this component does not have a reasonable baseline and that LayoutManagers should not align this component on its baseline. 
 The default implementation returns -1. Subclasses that support baseline should override appropriately. If a value >= 0 is returned, then the component has a valid baseline for any size >= the minimum size and getBaselineResizeBehavior can be used to determine how the baseline changes with size. 
Params:
  • width – the width to get the baseline for
  • height – the height to get the baseline for
Throws:
See Also:
Returns:the baseline or < 0 indicating there is no reasonable
        baseline
Since:1.6
/**
     * Returns the baseline.  The baseline is measured from the top of
     * the component.  This method is primarily meant for
     * {@code LayoutManager}s to align components along their
     * baseline.  A return value less than 0 indicates this component
     * does not have a reasonable baseline and that
     * {@code LayoutManager}s should not align this component on
     * its baseline.
     * <p>
     * The default implementation returns -1.  Subclasses that support
     * baseline should override appropriately.  If a value &gt;= 0 is
     * returned, then the component has a valid baseline for any
     * size &gt;= the minimum size and {@code getBaselineResizeBehavior}
     * can be used to determine how the baseline changes with size.
     *
     * @param width the width to get the baseline for
     * @param height the height to get the baseline for
     * @return the baseline or &lt; 0 indicating there is no reasonable
     *         baseline
     * @throws IllegalArgumentException if width or height is &lt; 0
     * @see #getBaselineResizeBehavior
     * @see java.awt.FontMetrics
     * @since 1.6
     */
    public int getBaseline(int width, int height) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException(
                    "Width and height must be >= 0");
        }
        return -1;
    }

    
Returns an enum indicating how the baseline of the component
changes as the size changes.  This method is primarily meant for
layout managers and GUI builders.

 The default implementation returns BaselineResizeBehavior.OTHER. Subclasses that have a baseline should override appropriately. Subclasses should never return null; if the baseline can not be calculated return BaselineResizeBehavior.OTHER. Callers should first ask for the baseline using getBaseline and if a value >= 0 is returned use this method. It is acceptable for this method to return a value other than BaselineResizeBehavior.OTHER even if getBaseline returns a value less than 0. 
See Also:
Returns:an enum indicating how the baseline changes as the component
        size changes
Since:1.6
/**
     * Returns an enum indicating how the baseline of the component
     * changes as the size changes.  This method is primarily meant for
     * layout managers and GUI builders.
     * <p>
     * The default implementation returns
     * {@code BaselineResizeBehavior.OTHER}.  Subclasses that have a
     * baseline should override appropriately.  Subclasses should
     * never return {@code null}; if the baseline can not be
     * calculated return {@code BaselineResizeBehavior.OTHER}.  Callers
     * should first ask for the baseline using
     * {@code getBaseline} and if a value &gt;= 0 is returned use
     * this method.  It is acceptable for this method to return a
     * value other than {@code BaselineResizeBehavior.OTHER} even if
     * {@code getBaseline} returns a value less than 0.
     *
     * @return an enum indicating how the baseline changes as the component
     *         size changes
     * @see #getBaseline(int, int)
     * @since 1.6
     */
    public BaselineResizeBehavior getBaselineResizeBehavior() {
        return BaselineResizeBehavior.OTHER;
    }

    
Prompts the layout manager to lay out this component. This is
usually called when the component (more specifically, container)
is validated.

See Also:
/**
     * Prompts the layout manager to lay out this component. This is
     * usually called when the component (more specifically, container)
     * is validated.
     * @see #validate
     * @see LayoutManager
     */
    public void doLayout() {
        layout();
    }

    
Deprecated:As of JDK version 1.1, replaced by doLayout().
/**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code doLayout()}.
     */
    @Deprecated
    public void layout() {
    }

    
Validates this component.


The meaning of the term validating is defined by the ancestors of this class. See Container.validate for more details. 
See Also:
Since:    1.0
/**
     * Validates this component.
     * <p>
     * The meaning of the term <i>validating</i> is defined by the ancestors of
     * this class. See {@link Container#validate} for more details.
     *
     * @see       #invalidate
     * @see       #doLayout()
     * @see       LayoutManager
     * @see       Container#validate
     * @since     1.0
     */
    public void validate() {
        synchronized (getTreeLock()) {
            ComponentPeer peer = this.peer;
            boolean wasValid = isValid();
            if (!wasValid && peer != null) {
                Font newfont = getFont();
                Font oldfont = peerFont;
                if (newfont != null && !Objects.equals(oldfont, newfont)) {
                    peer.setFont(newfont);
                    peerFont = newfont;
                }
                peer.layout();
            }
            valid = true;
            if (!wasValid) {
                mixOnValidating();
            }
        }
    }

    
Invalidates this component and its ancestors.

 By default, all the ancestors of the component up to the top-most container of the hierarchy are marked invalid. If the 
java.awt.smartInvalidate system property is set to true, invalidation stops on the nearest validate root of this component. Marking a container invalid indicates that the container needs to
be laid out.


This method is called automatically when any layout-related information
changes (e.g. setting the bounds of the component, or adding the
component to a container).


This method might be called often, so it should work fast.

See Also:
Since:    1.0
/**
     * Invalidates this component and its ancestors.
     * <p>
     * By default, all the ancestors of the component up to the top-most
     * container of the hierarchy are marked invalid. If the {@code
     * java.awt.smartInvalidate} system property is set to {@code true},
     * invalidation stops on the nearest validate root of this component.
     * Marking a container <i>invalid</i> indicates that the container needs to
     * be laid out.
     * <p>
     * This method is called automatically when any layout-related information
     * changes (e.g. setting the bounds of the component, or adding the
     * component to a container).
     * <p>
     * This method might be called often, so it should work fast.
     *
     * @see       #validate
     * @see       #doLayout
     * @see       LayoutManager
     * @see       java.awt.Container#isValidateRoot
     * @since     1.0
     */
    public void invalidate() {
        synchronized (getTreeLock()) {
            /* Nullify cached layout and size information.
             * For efficiency, propagate invalidate() upwards only if
             * some other component hasn't already done so first.
             */
            valid = false;
            if (!isPreferredSizeSet()) {
                prefSize = null;
            }
            if (!isMinimumSizeSet()) {
                minSize = null;
            }
            if (!isMaximumSizeSet()) {
                maxSize = null;
            }
            invalidateParent();
        }
    }

    
Invalidates the parent of this component if any.
This method MUST BE invoked under the TreeLock.

/**
     * Invalidates the parent of this component if any.
     *
     * This method MUST BE invoked under the TreeLock.
     */
    void invalidateParent() {
        if (parent != null) {
            parent.invalidateIfValid();
        }
    }

    
Invalidates the component unless it is already invalid.

/** Invalidates the component unless it is already invalid.
     */
    final void invalidateIfValid() {
        if (isValid()) {
            invalidate();
        }
    }

    
Revalidates the component hierarchy up to the nearest validate root.


This method first invalidates the component hierarchy starting from this
component up to the nearest validate root. Afterwards, the component
hierarchy is validated starting from the nearest validate root.

 This is a convenience method supposed to help application developers avoid looking for validate roots manually. Basically, it's equivalent to first calling the invalidate() method on this component, and then calling the validate() method on the nearest validate root. 
See Also:
Since:1.7
/**
     * Revalidates the component hierarchy up to the nearest validate root.
     * <p>
     * This method first invalidates the component hierarchy starting from this
     * component up to the nearest validate root. Afterwards, the component
     * hierarchy is validated starting from the nearest validate root.
     * <p>
     * This is a convenience method supposed to help application developers
     * avoid looking for validate roots manually. Basically, it's equivalent to
     * first calling the {@link #invalidate()} method on this component, and
     * then calling the {@link #validate()} method on the nearest validate
     * root.
     *
     * @see Container#isValidateRoot
     * @since 1.7
     */
    public void revalidate() {
        revalidateSynchronously();
    }

    
Revalidates the component synchronously.

/**
     * Revalidates the component synchronously.
     */
    final void revalidateSynchronously() {
        synchronized (getTreeLock()) {
            invalidate();

            Container root = getContainer();
            if (root == null) {
                // There's no parents. Just validate itself.
                validate();
            } else {
                while (!root.isValidateRoot()) {
                    if (root.getContainer() == null) {
                        // If there's no validate roots, we'll validate the
                        // topmost container
                        break;
                    }

                    root = root.getContainer();
                }

                root.validate();
            }
        }
    }

    
Creates a graphics context for this component. This method will return null if this component is currently not displayable. 
See Also:
Returns:a graphics context for this component, or null if it has none
Since:    1.0
/**
     * Creates a graphics context for this component. This method will
     * return {@code null} if this component is currently not
     * displayable.
     * @return a graphics context for this component, or {@code null}
     *             if it has none
     * @see       #paint
     * @since     1.0
     */
    public Graphics getGraphics() {
        if (peer instanceof LightweightPeer) {
            // This is for a lightweight component, need to
            // translate coordinate spaces and clip relative
            // to the parent.
            if (parent == null) return null;
            Graphics g = parent.getGraphics();
            if (g == null) return null;
            if (g instanceof ConstrainableGraphics) {
                ((ConstrainableGraphics) g).constrain(x, y, width, height);
            } else {
                g.translate(x,y);
                g.setClip(0, 0, width, height);
            }
            g.setFont(getFont());
            return g;
        } else {
            ComponentPeer peer = this.peer;
            return (peer != null) ? peer.getGraphics() : null;
        }
    }

    final Graphics getGraphics_NoClientCode() {
        ComponentPeer peer = this.peer;
        if (peer instanceof LightweightPeer) {
            // This is for a lightweight component, need to
            // translate coordinate spaces and clip relative
            // to the parent.
            Container parent = this.parent;
            if (parent == null) return null;
            Graphics g = parent.getGraphics_NoClientCode();
            if (g == null) return null;
            if (g instanceof ConstrainableGraphics) {
                ((ConstrainableGraphics) g).constrain(x, y, width, height);
            } else {
                g.translate(x,y);
                g.setClip(0, 0, width, height);
            }
            g.setFont(getFont_NoClientCode());
            return g;
        } else {
            return (peer != null) ? peer.getGraphics() : null;
        }
    }

    
Gets the font metrics for the specified font. Warning: Since Font metrics are affected by the FontRenderContext and this method does not provide one, it can return only metrics for the default render context which may not match that used when rendering on the Component if Graphics2D functionality is being used. Instead metrics can be obtained at rendering time by calling Graphics.getFontMetrics() or text measurement APIs on the Font class. 
Params:
  • font – the font for which font metrics is to be
         obtained
See Also:
Returns:the font metrics for font
Since:    1.0
/**
     * Gets the font metrics for the specified font.
     * Warning: Since Font metrics are affected by the
     * {@link java.awt.font.FontRenderContext FontRenderContext} and
     * this method does not provide one, it can return only metrics for
     * the default render context which may not match that used when
     * rendering on the Component if {@link Graphics2D} functionality is being
     * used. Instead metrics can be obtained at rendering time by calling
     * {@link Graphics#getFontMetrics()} or text measurement APIs on the
     * {@link Font Font} class.
     * @param font the font for which font metrics is to be
     *          obtained
     * @return the font metrics for {@code font}
     * @see       #getFont
     * @see       java.awt.peer.ComponentPeer#getFontMetrics(Font)
     * @see       Toolkit#getFontMetrics(Font)
     * @since     1.0
     */
    public FontMetrics getFontMetrics(Font font) {
        // This is an unsupported hack, but left in for a customer.
        // Do not remove.
        FontManager fm = FontManagerFactory.getInstance();
        if (fm instanceof SunFontManager
            && ((SunFontManager) fm).usePlatformFontMetrics()) {

            if (peer != null &&
                !(peer instanceof LightweightPeer)) {
                return peer.getFontMetrics(font);
            }
        }
        return sun.font.FontDesignMetrics.getMetrics(font);
    }

    
Sets the cursor image to the specified cursor. This cursor image is displayed when the contains method for this component returns true for the current cursor location, and this Component is visible, displayable, and enabled. Setting the cursor of a Container causes that cursor to be displayed within all of the container's subcomponents, except for those that have a non-null cursor. 

The method may have no visual effect if the Java platform
implementation and/or the native system do not support
changing the mouse cursor shape.

Params:
  • cursor – One of the constants defined by the Cursor class; if this parameter is null then this component will inherit the cursor of its parent
See Also:
Since:    1.1
/**
     * Sets the cursor image to the specified cursor.  This cursor
     * image is displayed when the {@code contains} method for
     * this component returns true for the current cursor location, and
     * this Component is visible, displayable, and enabled. Setting the
     * cursor of a {@code Container} causes that cursor to be displayed
     * within all of the container's subcomponents, except for those
     * that have a non-{@code null} cursor.
     * <p>
     * The method may have no visual effect if the Java platform
     * implementation and/or the native system do not support
     * changing the mouse cursor shape.
     * @param cursor One of the constants defined
     *          by the {@code Cursor} class;
     *          if this parameter is {@code null}
     *          then this component will inherit
     *          the cursor of its parent
     * @see       #isEnabled
     * @see       #isShowing
     * @see       #getCursor
     * @see       #contains
     * @see       Toolkit#createCustomCursor
     * @see       Cursor
     * @since     1.1
     */
    public void setCursor(Cursor cursor) {
        this.cursor = cursor;
        updateCursorImmediately();
    }

    
Updates the cursor.  May not be invoked from the native
message pump.

/**
     * Updates the cursor.  May not be invoked from the native
     * message pump.
     */
    final void updateCursorImmediately() {
        if (peer instanceof LightweightPeer) {
            Container nativeContainer = getNativeContainer();

            if (nativeContainer == null) return;

            ComponentPeer cPeer = nativeContainer.peer;

            if (cPeer != null) {
                cPeer.updateCursorImmediately();
            }
        } else if (peer != null) {
            peer.updateCursorImmediately();
        }
    }

    
Gets the cursor set in the component. If the component does not have a cursor set, the cursor of its parent is returned. If no cursor is set in the entire hierarchy, Cursor.DEFAULT_CURSOR is returned. 
See Also:
Returns:the cursor for this component
Since:1.1
/**
     * Gets the cursor set in the component. If the component does
     * not have a cursor set, the cursor of its parent is returned.
     * If no cursor is set in the entire hierarchy,
     * {@code Cursor.DEFAULT_CURSOR} is returned.
     *
     * @return the cursor for this component
     * @see #setCursor
     * @since 1.1
     */
    public Cursor getCursor() {
        return getCursor_NoClientCode();
    }

    final Cursor getCursor_NoClientCode() {
        Cursor cursor = this.cursor;
        if (cursor != null) {
            return cursor;
        }
        Container parent = this.parent;
        if (parent != null) {
            return parent.getCursor_NoClientCode();
        } else {
            return Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
        }
    }

    
Returns whether the cursor has been explicitly set for this Component. If this method returns false, this Component is inheriting its cursor from an ancestor. 
Returns:true if the cursor has been explicitly set for this Component; false otherwise.
Since:1.4
/**
     * Returns whether the cursor has been explicitly set for this Component.
     * If this method returns {@code false}, this Component is inheriting
     * its cursor from an ancestor.
     *
     * @return {@code true} if the cursor has been explicitly set for this
     *         Component; {@code false} otherwise.
     * @since 1.4
     */
    public boolean isCursorSet() {
        return (cursor != null);
    }

    
Paints this component.

 This method is called when the contents of the component should be painted; such as when the component is first being shown or is damaged and in need of repair. The clip rectangle in the Graphics parameter is set to the area which needs to be painted. Subclasses of Component that override this method need not call super.paint(g). 
 For performance reasons, Components with zero width or height aren't considered to need painting when they are first shown, and also aren't considered to need repair. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

Params:
  • g – the graphics context to use for painting
See Also:
Since:    1.0
/**
     * Paints this component.
     * <p>
     * This method is called when the contents of the component should
     * be painted; such as when the component is first being shown or
     * is damaged and in need of repair.  The clip rectangle in the
     * {@code Graphics} parameter is set to the area
     * which needs to be painted.
     * Subclasses of {@code Component} that override this
     * method need not call {@code super.paint(g)}.
     * <p>
     * For performance reasons, {@code Component}s with zero width
     * or height aren't considered to need painting when they are first shown,
     * and also aren't considered to need repair.
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
     *
     * @param g the graphics context to use for painting
     * @see       #update
     * @since     1.0
     */
    public void paint(Graphics g) {
    }

    
Updates this component.

 If this component is not a lightweight component, the AWT calls the update method in response to a call to repaint. You can assume that the background is not cleared. 
 The update method of Component calls this component's paint method to redraw this component. This method is commonly overridden by subclasses which need to do additional work in response to a call to repaint. Subclasses of Component that override this method should either call super.update(g), or call paint(g) directly from their update method. 
 The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

Params:
  • g – the specified context to use for updating
See Also:
Since:    1.0
/**
     * Updates this component.
     * <p>
     * If this component is not a lightweight component, the
     * AWT calls the {@code update} method in response to
     * a call to {@code repaint}.  You can assume that
     * the background is not cleared.
     * <p>
     * The {@code update} method of {@code Component}
     * calls this component's {@code paint} method to redraw
     * this component.  This method is commonly overridden by subclasses
     * which need to do additional work in response to a call to
     * {@code repaint}.
     * Subclasses of Component that override this method should either
     * call {@code super.update(g)}, or call {@code paint(g)}
     * directly from their {@code update} method.
     * <p>
     * The origin of the graphics context, its
     * ({@code 0},&nbsp;{@code 0}) coordinate point, is the
     * top-left corner of this component. The clipping region of the
     * graphics context is the bounding rectangle of this component.
     *
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
     *
     * @param g the specified context to use for updating
     * @see       #paint
     * @see       #repaint()
     * @since     1.0
     */
    public void update(Graphics g) {
        paint(g);
    }

    
Paints this component and all of its subcomponents.

 The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component. 
Params:
  • g –   the graphics context to use for painting
See Also:
Since:    1.0
/**
     * Paints this component and all of its subcomponents.
     * <p>
     * The origin of the graphics context, its
     * ({@code 0},&nbsp;{@code 0}) coordinate point, is the
     * top-left corner of this component. The clipping region of the
     * graphics context is the bounding rectangle of this component.
     *
     * @param     g   the graphics context to use for painting
     * @see       #paint
     * @since     1.0
     */
    public void paintAll(Graphics g) {
        if (isShowing()) {
            GraphicsCallback.PeerPaintCallback.getInstance().
                runOneComponent(this, new Rectangle(0, 0, width, height),
                                g, g.getClip(),
                                GraphicsCallback.LIGHTWEIGHTS |
                                GraphicsCallback.HEAVYWEIGHTS);
        }
    }

    
Simulates the peer callbacks into java.awt for painting of
lightweight Components.

Params:
  • g –   the graphics context to use for painting
See Also:
/**
     * Simulates the peer callbacks into java.awt for painting of
     * lightweight Components.
     * @param     g   the graphics context to use for painting
     * @see       #paintAll
     */
    void lightweightPaint(Graphics g) {
        paint(g);
    }

    
Paints all the heavyweight subcomponents.

/**
     * Paints all the heavyweight subcomponents.
     */
    void paintHeavyweightComponents(Graphics g) {
    }

    
Repaints this component.

 If this component is a lightweight component, this method causes a call to this component's paint method as soon as possible. Otherwise, this method causes a call to this component's update method as soon as possible. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

See Also:
Since:    1.0
/**
     * Repaints this component.
     * <p>
     * If this component is a lightweight component, this method
     * causes a call to this component's {@code paint}
     * method as soon as possible.  Otherwise, this method causes
     * a call to this component's {@code update} method as soon
     * as possible.
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.

     *
     * @see       #update(Graphics)
     * @since     1.0
     */
    public void repaint() {
        repaint(0, 0, 0, width, height);
    }

    
Repaints the component. If this component is a lightweight component, this results in a call to paint within tm milliseconds. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

Params:
  • tm – maximum time in milliseconds before update
See Also:
Since:1.0
/**
     * Repaints the component.  If this component is a lightweight
     * component, this results in a call to {@code paint}
     * within {@code tm} milliseconds.
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
     *
     * @param tm maximum time in milliseconds before update
     * @see #paint
     * @see #update(Graphics)
     * @since 1.0
     */
    public void repaint(long tm) {
        repaint(tm, 0, 0, width, height);
    }

    
Repaints the specified rectangle of this component.

 If this component is a lightweight component, this method causes a call to this component's paint method as soon as possible. Otherwise, this method causes a call to this component's update method as soon as possible. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

Params:
  • x –   the x coordinate
  • y –   the y coordinate
  • width –   the width
  • height –  the height
See Also:
Since:    1.0
/**
     * Repaints the specified rectangle of this component.
     * <p>
     * If this component is a lightweight component, this method
     * causes a call to this component's {@code paint} method
     * as soon as possible.  Otherwise, this method causes a call to
     * this component's {@code update} method as soon as possible.
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
     *
     * @param     x   the <i>x</i> coordinate
     * @param     y   the <i>y</i> coordinate
     * @param     width   the width
     * @param     height  the height
     * @see       #update(Graphics)
     * @since     1.0
     */
    public void repaint(int x, int y, int width, int height) {
        repaint(0, x, y, width, height);
    }

    
Repaints the specified rectangle of this component within tm milliseconds. 
 If this component is a lightweight component, this method causes a call to this component's paint method. Otherwise, this method causes a call to this component's update method. 

Note: For more information on the paint mechanisms utilitized
by AWT and Swing, including information on how to write the most
efficient painting code, see
Painting in AWT and Swing.

Params:
  • tm –   maximum time in milliseconds before update
  • x –    the x coordinate
  • y –    the y coordinate
  • width –    the width
  • height –   the height
See Also:
Since:    1.0
/**
     * Repaints the specified rectangle of this component within
     * {@code tm} milliseconds.
     * <p>
     * If this component is a lightweight component, this method causes
     * a call to this component's {@code paint} method.
     * Otherwise, this method causes a call to this component's
     * {@code update} method.
     * <p>
     * <b>Note</b>: For more information on the paint mechanisms utilitized
     * by AWT and Swing, including information on how to write the most
     * efficient painting code, see
     * <a href="http://www.oracle.com/technetwork/java/painting-140037.html">Painting in AWT and Swing</a>.
     *
     * @param     tm   maximum time in milliseconds before update
     * @param     x    the <i>x</i> coordinate
     * @param     y    the <i>y</i> coordinate
     * @param     width    the width
     * @param     height   the height
     * @see       #update(Graphics)
     * @since     1.0
     */
    public void repaint(long tm, int x, int y, int width, int height) {
        if (this.peer instanceof LightweightPeer) {
            // Needs to be translated to parent coordinates since
            // a parent native container provides the actual repaint
            // services.  Additionally, the request is restricted to
            // the bounds of the component.
            if (parent != null) {
                if (x < 0) {
                    width += x;
                    x = 0;
                }
                if (y < 0) {
                    height += y;
                    y = 0;
                }

                int pwidth = (width > this.width) ? this.width : width;
                int pheight = (height > this.height) ? this.height : height;

                if (pwidth <= 0 || pheight <= 0) {
                    return;
                }

                int px = this.x + x;
                int py = this.y + y;
                parent.repaint(tm, px, py, pwidth, pheight);
            }
        } else {
            if (isVisible() && (this.peer != null) &&
                (width > 0) && (height > 0)) {
                PaintEvent e = new PaintEvent(this, PaintEvent.UPDATE,
                                              new Rectangle(x, y, width, height));
                SunToolkit.postEvent(SunToolkit.targetToAppContext(this), e);
            }
        }
    }

    
Prints this component. Applications should override this method
for components that must do special processing before being
printed or should be printed differently than they are painted.

 The default implementation of this method calls the paint method. 
 The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component. 
Params:
  • g –   the graphics context to use for printing
See Also:
Since:    1.0
/**
     * Prints this component. Applications should override this method
     * for components that must do special processing before being
     * printed or should be printed differently than they are painted.
     * <p>
     * The default implementation of this method calls the
     * {@code paint} method.
     * <p>
     * The origin of the graphics context, its
     * ({@code 0},&nbsp;{@code 0}) coordinate point, is the
     * top-left corner of this component. The clipping region of the
     * graphics context is the bounding rectangle of this component.
     * @param     g   the graphics context to use for printing
     * @see       #paint(Graphics)
     * @since     1.0
     */
    public void print(Graphics g) {
        paint(g);
    }

    
Prints this component and all of its subcomponents.

 The origin of the graphics context, its (0, 0) coordinate point, is the top-left corner of this component. The clipping region of the graphics context is the bounding rectangle of this component. 
Params:
  • g –   the graphics context to use for printing
See Also:
Since:    1.0
/**
     * Prints this component and all of its subcomponents.
     * <p>
     * The origin of the graphics context, its
     * ({@code 0},&nbsp;{@code 0}) coordinate point, is the
     * top-left corner of this component. The clipping region of the
     * graphics context is the bounding rectangle of this component.
     * @param     g   the graphics context to use for printing
     * @see       #print(Graphics)
     * @since     1.0
     */
    public void printAll(Graphics g) {
        if (isShowing()) {
            GraphicsCallback.PeerPrintCallback.getInstance().
                runOneComponent(this, new Rectangle(0, 0, width, height),
                                g, g.getClip(),
                                GraphicsCallback.LIGHTWEIGHTS |
                                GraphicsCallback.HEAVYWEIGHTS);
        }
    }

    
Simulates the peer callbacks into java.awt for printing of
lightweight Components.

Params:
  • g –   the graphics context to use for printing
See Also:
/**
     * Simulates the peer callbacks into java.awt for printing of
     * lightweight Components.
     * @param     g   the graphics context to use for printing
     * @see       #printAll
     */
    void lightweightPrint(Graphics g) {
        print(g);
    }

    
Prints all the heavyweight subcomponents.

/**
     * Prints all the heavyweight subcomponents.
     */
    void printHeavyweightComponents(Graphics g) {
    }

    private Insets getInsets_NoClientCode() {
        ComponentPeer peer = this.peer;
        if (peer instanceof ContainerPeer) {
            return (Insets)((ContainerPeer)peer).getInsets().clone();
        }
        return new Insets(0, 0, 0, 0);
    }

    
Repaints the component when the image has changed. This imageUpdate method of an ImageObserver is called when more information about an image which had been previously requested using an asynchronous routine such as the drawImage method of Graphics becomes available. See the definition of imageUpdate for more information on this method and its arguments. 
 The imageUpdate method of Component incrementally draws an image on the component as more of the bits of the image are available. 
 If the system property awt.image.incrementaldraw is missing or has the value true, the image is incrementally drawn. If the system property has any other value, then the image is not drawn until it has been completely loaded. 
 Also, if incremental drawing is in effect, the value of the system property awt.image.redrawrate is interpreted as an integer to give the maximum redraw rate, in milliseconds. If the system property is missing or cannot be interpreted as an integer, the redraw rate is once every 100ms. 
 The interpretation of the x, y, width, and height arguments depends on the value of the infoflags argument. 
Params:
  • img –   the image being observed
  • infoflags –  see imageUpdate for more information
  • x –   the x coordinate
  • y –   the y coordinate
  • w –   the width
  • h –   the height
See Also:
Returns: false if the infoflags indicate that the image is completely loaded; true otherwise.
Since:  1.0
/**
     * Repaints the component when the image has changed.
     * This {@code imageUpdate} method of an {@code ImageObserver}
     * is called when more information about an
     * image which had been previously requested using an asynchronous
     * routine such as the {@code drawImage} method of
     * {@code Graphics} becomes available.
     * See the definition of {@code imageUpdate} for
     * more information on this method and its arguments.
     * <p>
     * The {@code imageUpdate} method of {@code Component}
     * incrementally draws an image on the component as more of the bits
     * of the image are available.
     * <p>
     * If the system property {@code awt.image.incrementaldraw}
     * is missing or has the value {@code true}, the image is
     * incrementally drawn. If the system property has any other value,
     * then the image is not drawn until it has been completely loaded.
     * <p>
     * Also, if incremental drawing is in effect, the value of the
     * system property {@code awt.image.redrawrate} is interpreted
     * as an integer to give the maximum redraw rate, in milliseconds. If
     * the system property is missing or cannot be interpreted as an
     * integer, the redraw rate is once every 100ms.
     * <p>
     * The interpretation of the {@code x}, {@code y},
     * {@code width}, and {@code height} arguments depends on
     * the value of the {@code infoflags} argument.
     *
     * @param     img   the image being observed
     * @param     infoflags   see {@code imageUpdate} for more information
     * @param     x   the <i>x</i> coordinate
     * @param     y   the <i>y</i> coordinate
     * @param     w   the width
     * @param     h   the height
     * @return    {@code false} if the infoflags indicate that the
     *            image is completely loaded; {@code true} otherwise.
     *
     * @see     java.awt.image.ImageObserver
     * @see     Graphics#drawImage(Image, int, int, Color, java.awt.image.ImageObserver)
     * @see     Graphics#drawImage(Image, int, int, java.awt.image.ImageObserver)
     * @see     Graphics#drawImage(Image, int, int, int, int, Color, java.awt.image.ImageObserver)
     * @see     Graphics#drawImage(Image, int, int, int, int, java.awt.image.ImageObserver)
     * @see     java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int)
     * @since   1.0
     */
    public boolean imageUpdate(Image img, int infoflags,
                               int x, int y, int w, int h) {
        int rate = -1;
        if ((infoflags & (FRAMEBITS|ALLBITS)) != 0) {
            rate = 0;
        } else if ((infoflags & SOMEBITS) != 0) {
            if (isInc) {
                rate = incRate;
                if (rate < 0) {
                    rate = 0;
                }
            }
        }
        if (rate >= 0) {
            repaint(rate, 0, 0, width, height);
        }
        return (infoflags & (ALLBITS|ABORT)) == 0;
    }

    
Creates an image from the specified image producer.

Params:
  • producer –  the image producer
Returns:   the image produced
Since:    1.0
/**
     * Creates an image from the specified image producer.
     * @param     producer  the image producer
     * @return    the image produced
     * @since     1.0
     */
    public Image createImage(ImageProducer producer) {
        ComponentPeer peer = this.peer;
        if ((peer != null) && ! (peer instanceof LightweightPeer)) {
            return peer.createImage(producer);
        }
        return getToolkit().createImage(producer);
    }

    
Creates an off-screen drawable image to be used for double buffering.

Params:
  • width – the specified width
  • height – the specified height
See Also:
Returns:an off-screen drawable image, which can be used for double buffering. The null value if the component is not displayable or GraphicsEnvironment.isHeadless() returns true.
Since:1.0
/**
     * Creates an off-screen drawable image to be used for double buffering.
     *
     * @param  width the specified width
     * @param  height the specified height
     * @return an off-screen drawable image, which can be used for double
     *         buffering. The {@code null} value if the component is not
     *         displayable or {@code GraphicsEnvironment.isHeadless()} returns
     *         {@code true}.
     * @see #isDisplayable
     * @see GraphicsEnvironment#isHeadless
     * @since 1.0
     */
    public Image createImage(int width, int height) {
        ComponentPeer peer = this.peer;
        if (peer instanceof LightweightPeer) {
            if (parent != null) { return parent.createImage(width, height); }
            else { return null;}
        } else {
            return (peer != null) ? peer.createImage(width, height) : null;
        }
    }

    
Creates a volatile off-screen drawable image to be used for double
buffering.

Params:
  • width – the specified width
  • height – the specified height
See Also:
Returns:an off-screen drawable image, which can be used for double buffering. The null value if the component is not displayable or GraphicsEnvironment.isHeadless() returns true.
Since:1.4
/**
     * Creates a volatile off-screen drawable image to be used for double
     * buffering.
     *
     * @param  width the specified width
     * @param  height the specified height
     * @return an off-screen drawable image, which can be used for double
     *         buffering. The {@code null} value if the component is not
     *         displayable or {@code GraphicsEnvironment.isHeadless()} returns
     *         {@code true}.
     * @see java.awt.image.VolatileImage
     * @see #isDisplayable
     * @see GraphicsEnvironment#isHeadless
     * @since 1.4
     */
    public VolatileImage createVolatileImage(int width, int height) {
        ComponentPeer peer = this.peer;
        if (peer instanceof LightweightPeer) {
            if (parent != null) {
                return parent.createVolatileImage(width, height);
            }
            else { return null;}
        } else {
            return (peer != null) ?
                peer.createVolatileImage(width, height) : null;
        }
    }

    
Creates a volatile off-screen drawable image, with the given capabilities. The contents of this image may be lost at any time due to operating system issues, so the image must be managed via the VolatileImage interface. 
Params:
  • width – the specified width
  • height – the specified height
  • caps – the image capabilities
Throws:
  • AWTException – if an image with the specified capabilities cannot
        be created
See Also:
Returns:a VolatileImage object, which can be used to manage surface contents loss and capabilities. The null value if the component is not displayable or GraphicsEnvironment.isHeadless() returns true.
Since:1.4
/**
     * Creates a volatile off-screen drawable image, with the given
     * capabilities. The contents of this image may be lost at any time due to
     * operating system issues, so the image must be managed via the
     * {@code VolatileImage} interface.
     *
     * @param  width the specified width
     * @param  height the specified height
     * @param  caps the image capabilities
     * @return a VolatileImage object, which can be used to manage surface
     *         contents loss and capabilities. The {@code null} value if the
     *         component is not displayable or
     *         {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
     * @throws AWTException if an image with the specified capabilities cannot
     *         be created
     * @see java.awt.image.VolatileImage
     * @since 1.4
     */
    public VolatileImage createVolatileImage(int width, int height,
                                             ImageCapabilities caps)
            throws AWTException {
        // REMIND : check caps
        return createVolatileImage(width, height);
    }

    
Prepares an image for rendering on this component.  The image
data is downloaded asynchronously in another thread and the
appropriate screen representation of the image is generated.

Params:
  • image –  the Image for which to prepare a screen representation
  • observer –  the ImageObserver object to be notified as the image is being prepared
Returns: true if the image has already been fully prepared; false otherwise
Since:    1.0
/**
     * Prepares an image for rendering on this component.  The image
     * data is downloaded asynchronously in another thread and the
     * appropriate screen representation of the image is generated.
     * @param     image   the {@code Image} for which to
     *                    prepare a screen representation
     * @param     observer   the {@code ImageObserver} object
     *                       to be notified as the image is being prepared
     * @return    {@code true} if the image has already been fully
     *           prepared; {@code false} otherwise
     * @since     1.0
     */
    public boolean prepareImage(Image image, ImageObserver observer) {
        return prepareImage(image, -1, -1, observer);
    }

    
Prepares an image for rendering on this component at the
specified width and height.


The image data is downloaded asynchronously in another thread,
and an appropriately scaled screen representation of the image is
generated.

Params:
  • image –  the instance of Image for which to prepare a screen representation
  • width –    the width of the desired screen representation
  • height –   the height of the desired screen representation
  • observer –  the ImageObserver object to be notified as the image is being prepared
See Also:
Returns: true if the image has already been fully prepared; false otherwise
Since:    1.0
/**
     * Prepares an image for rendering on this component at the
     * specified width and height.
     * <p>
     * The image data is downloaded asynchronously in another thread,
     * and an appropriately scaled screen representation of the image is
     * generated.
     * @param     image    the instance of {@code Image}
     *            for which to prepare a screen representation
     * @param     width    the width of the desired screen representation
     * @param     height   the height of the desired screen representation
     * @param     observer   the {@code ImageObserver} object
     *            to be notified as the image is being prepared
     * @return    {@code true} if the image has already been fully
     *          prepared; {@code false} otherwise
     * @see       java.awt.image.ImageObserver
     * @since     1.0
     */
    public boolean prepareImage(Image image, int width, int height,
                                ImageObserver observer) {
        ComponentPeer peer = this.peer;
        if (peer instanceof LightweightPeer) {
            return (parent != null)
                ? parent.prepareImage(image, width, height, observer)
                : getToolkit().prepareImage(image, width, height, observer);
        } else {
            return (peer != null)
                ? peer.prepareImage(image, width, height, observer)
                : getToolkit().prepareImage(image, width, height, observer);
        }
    }

    
Returns the status of the construction of a screen representation
of the specified image.

 This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image. 
 Information on the flags returned by this method can be found with the discussion of the ImageObserver interface. 
Params:
  • image –  the Image object whose status is being checked
  • observer –  the ImageObserver object to be notified as the image is being prepared
See Also:
Returns: the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available
Since:   1.0
/**
     * Returns the status of the construction of a screen representation
     * of the specified image.
     * <p>
     * This method does not cause the image to begin loading. An
     * application must use the {@code prepareImage} method
     * to force the loading of an image.
     * <p>
     * Information on the flags returned by this method can be found
     * with the discussion of the {@code ImageObserver} interface.
     * @param     image   the {@code Image} object whose status
     *            is being checked
     * @param     observer   the {@code ImageObserver}
     *            object to be notified as the image is being prepared
     * @return  the bitwise inclusive <b>OR</b> of
     *            {@code ImageObserver} flags indicating what
     *            information about the image is currently available
     * @see      #prepareImage(Image, int, int, java.awt.image.ImageObserver)
     * @see      Toolkit#checkImage(Image, int, int, java.awt.image.ImageObserver)
     * @see      java.awt.image.ImageObserver
     * @since    1.0
     */
    public int checkImage(Image image, ImageObserver observer) {
        return checkImage(image, -1, -1, observer);
    }

    
Returns the status of the construction of a screen representation
of the specified image.

 This method does not cause the image to begin loading. An application must use the prepareImage method to force the loading of an image. 
 The checkImage method of Component calls its peer's checkImage method to calculate the flags. If this component does not yet have a peer, the component's toolkit's checkImage method is called instead. 
 Information on the flags returned by this method can be found with the discussion of the ImageObserver interface. 
Params:
  • image –  the Image object whose status is being checked
  • width –   the width of the scaled version
                   whose status is to be checked
  • height –  the height of the scaled version
                   whose status is to be checked
  • observer –  the ImageObserver object to be notified as the image is being prepared
See Also:
Returns:   the bitwise inclusive OR of ImageObserver flags indicating what information about the image is currently available
Since:   1.0
/**
     * Returns the status of the construction of a screen representation
     * of the specified image.
     * <p>
     * This method does not cause the image to begin loading. An
     * application must use the {@code prepareImage} method
     * to force the loading of an image.
     * <p>
     * The {@code checkImage} method of {@code Component}
     * calls its peer's {@code checkImage} method to calculate
     * the flags. If this component does not yet have a peer, the
     * component's toolkit's {@code checkImage} method is called
     * instead.
     * <p>
     * Information on the flags returned by this method can be found
     * with the discussion of the {@code ImageObserver} interface.
     * @param     image   the {@code Image} object whose status
     *                    is being checked
     * @param     width   the width of the scaled version
     *                    whose status is to be checked
     * @param     height  the height of the scaled version
     *                    whose status is to be checked
     * @param     observer   the {@code ImageObserver} object
     *                    to be notified as the image is being prepared
     * @return    the bitwise inclusive <b>OR</b> of
     *            {@code ImageObserver} flags indicating what
     *            information about the image is currently available
     * @see      #prepareImage(Image, int, int, java.awt.image.ImageObserver)
     * @see      Toolkit#checkImage(Image, int, int, java.awt.image.ImageObserver)
     * @see      java.awt.image.ImageObserver
     * @since    1.0
     */
    public int checkImage(Image image, int width, int height,
                          ImageObserver observer) {
        ComponentPeer peer = this.peer;
        if (peer instanceof LightweightPeer) {
            return (parent != null)
                ? parent.checkImage(image, width, height, observer)
                : getToolkit().checkImage(image, width, height, observer);
        } else {
            return (peer != null)
                ? peer.checkImage(image, width, height, observer)
                : getToolkit().checkImage(image, width, height, observer);
        }
    }

    
Creates a new strategy for multi-buffering on this component. Multi-buffering is useful for rendering performance. This method attempts to create the best strategy available with the number of buffers supplied. It will always create a BufferStrategy with that number of buffers. A page-flipping strategy is attempted first, then a blitting strategy using accelerated buffers. Finally, an unaccelerated blitting strategy is used. 

Each time this method is called,
the existing buffer strategy for this component is discarded.

Params:
  • numBuffers – number of buffers to create, including the front buffer
Throws:
See Also:
Since:1.4
/**
     * Creates a new strategy for multi-buffering on this component.
     * Multi-buffering is useful for rendering performance.  This method
     * attempts to create the best strategy available with the number of
     * buffers supplied.  It will always create a {@code BufferStrategy}
     * with that number of buffers.
     * A page-flipping strategy is attempted first, then a blitting strategy
     * using accelerated buffers.  Finally, an unaccelerated blitting
     * strategy is used.
     * <p>
     * Each time this method is called,
     * the existing buffer strategy for this component is discarded.
     * @param numBuffers number of buffers to create, including the front buffer
     * @exception IllegalArgumentException if numBuffers is less than 1.
     * @exception IllegalStateException if the component is not displayable
     * @see #isDisplayable
     * @see Window#getBufferStrategy()
     * @see Canvas#getBufferStrategy()
     * @since 1.4
     */
    void createBufferStrategy(int numBuffers) {
        BufferCapabilities bufferCaps;
        if (numBuffers > 1) {
            // Try to create a page-flipping strategy
            bufferCaps = new BufferCapabilities(new ImageCapabilities(true),
                                                new ImageCapabilities(true),
                                                BufferCapabilities.FlipContents.UNDEFINED);
            try {
                createBufferStrategy(numBuffers, bufferCaps);
                return; // Success
            } catch (AWTException e) {
                // Failed
            }
        }
        // Try a blitting (but still accelerated) strategy
        bufferCaps = new BufferCapabilities(new ImageCapabilities(true),
                                            new ImageCapabilities(true),
                                            null);
        try {
            createBufferStrategy(numBuffers, bufferCaps);
            return; // Success
        } catch (AWTException e) {
            // Failed
        }
        // Try an unaccelerated blitting strategy
        bufferCaps = new BufferCapabilities(new ImageCapabilities(false),
                                            new ImageCapabilities(false),
                                            null);
        try {
            createBufferStrategy(numBuffers, bufferCaps);
            return; // Success
        } catch (AWTException e) {
            // Code should never reach here (an unaccelerated blitting
            // strategy should always work)
            throw new InternalError("Could not create a buffer strategy", e);
        }
    }

    
Creates a new strategy for multi-buffering on this component with the
required buffer capabilities.  This is useful, for example, if only
accelerated memory or page flipping is desired (as specified by the
buffer capabilities).

 Each time this method is called, dispose will be invoked on the existing BufferStrategy. 
Params:
  • numBuffers – number of buffers to create
  • caps – the required capabilities for creating the buffer strategy; cannot be null
Throws:
  • AWTException – if the capabilities supplied could not be
supported or met; this may happen, for example, if there is not enough
accelerated memory currently available, or if page flipping is specified
but not possible.
  • IllegalArgumentException – if numBuffers is less than 1, or if caps is null
See Also:
Since:1.4
/**
     * Creates a new strategy for multi-buffering on this component with the
     * required buffer capabilities.  This is useful, for example, if only
     * accelerated memory or page flipping is desired (as specified by the
     * buffer capabilities).
     * <p>
     * Each time this method
     * is called, {@code dispose} will be invoked on the existing
     * {@code BufferStrategy}.
     * @param numBuffers number of buffers to create
     * @param caps the required capabilities for creating the buffer strategy;
     * cannot be {@code null}
     * @exception AWTException if the capabilities supplied could not be
     * supported or met; this may happen, for example, if there is not enough
     * accelerated memory currently available, or if page flipping is specified
     * but not possible.
     * @exception IllegalArgumentException if numBuffers is less than 1, or if
     * caps is {@code null}
     * @see Window#getBufferStrategy()
     * @see Canvas#getBufferStrategy()
     * @since 1.4
     */
    void createBufferStrategy(int numBuffers,
                              BufferCapabilities caps) throws AWTException {
        // Check arguments
        if (numBuffers < 1) {
            throw new IllegalArgumentException(
                "Number of buffers must be at least 1");
        }
        if (caps == null) {
            throw new IllegalArgumentException("No capabilities specified");
        }
        // Destroy old buffers
        if (bufferStrategy != null) {
            bufferStrategy.dispose();
        }
        if (numBuffers == 1) {
            bufferStrategy = new SingleBufferStrategy(caps);
        } else {
            SunGraphicsEnvironment sge = (SunGraphicsEnvironment)
                GraphicsEnvironment.getLocalGraphicsEnvironment();
            if (!caps.isPageFlipping() && sge.isFlipStrategyPreferred(peer)) {
                caps = new ProxyCapabilities(caps);
            }
            // assert numBuffers > 1;
            if (caps.isPageFlipping()) {
                bufferStrategy = new FlipSubRegionBufferStrategy(numBuffers, caps);
            } else {
                bufferStrategy = new BltSubRegionBufferStrategy(numBuffers, caps);
            }
        }
    }

    
This is a proxy capabilities class used when a FlipBufferStrategy
is created instead of the requested Blit strategy.

See Also:
  • isFlipStrategyPreferred.isFlipStrategyPreferred(ComponentPeer)
/**
     * This is a proxy capabilities class used when a FlipBufferStrategy
     * is created instead of the requested Blit strategy.
     *
     * @see sun.java2d.SunGraphicsEnvironment#isFlipStrategyPreferred(ComponentPeer)
     */
    private class ProxyCapabilities extends ExtendedBufferCapabilities {
        private BufferCapabilities orig;
        private ProxyCapabilities(BufferCapabilities orig) {
            super(orig.getFrontBufferCapabilities(),
                  orig.getBackBufferCapabilities(),
                  orig.getFlipContents() ==
                      BufferCapabilities.FlipContents.BACKGROUND ?
                      BufferCapabilities.FlipContents.BACKGROUND :
                      BufferCapabilities.FlipContents.COPIED);
            this.orig = orig;
        }
    }

    
See Also:
Returns:the buffer strategy used by this component
Since:1.4
/**
     * @return the buffer strategy used by this component
     * @see Window#createBufferStrategy
     * @see Canvas#createBufferStrategy
     * @since 1.4
     */
    BufferStrategy getBufferStrategy() {
        return bufferStrategy;
    }

    
Returns:the back buffer currently used by this component's
BufferStrategy.  If there is no BufferStrategy or no
back buffer, this method returns null.
/**
     * @return the back buffer currently used by this component's
     * BufferStrategy.  If there is no BufferStrategy or no
     * back buffer, this method returns null.
     */
    Image getBackBuffer() {
        if (bufferStrategy != null) {
            if (bufferStrategy instanceof BltBufferStrategy) {
                BltBufferStrategy bltBS = (BltBufferStrategy)bufferStrategy;
                return bltBS.getBackBuffer();
            } else if (bufferStrategy instanceof FlipBufferStrategy) {
                FlipBufferStrategy flipBS = (FlipBufferStrategy)bufferStrategy;
                return flipBS.getBackBuffer();
            }
        }
        return null;
    }

    
Inner class for flipping buffers on a component. That component must be a Canvas or Window or Applet. 
Author:Michael Martak
See Also:
Since:1.4
/**
     * Inner class for flipping buffers on a component.  That component must
     * be a {@code Canvas} or {@code Window} or {@code Applet}.
     * @see Canvas
     * @see Window
     * @see Applet
     * @see java.awt.image.BufferStrategy
     * @author Michael Martak
     * @since 1.4
     */
    protected class FlipBufferStrategy extends BufferStrategy {
        
The number of buffers

/**
         * The number of buffers
         */
        protected int numBuffers; // = 0
        
The buffering capabilities

/**
         * The buffering capabilities
         */
        protected BufferCapabilities caps; // = null
        
The drawing buffer

/**
         * The drawing buffer
         */
        protected Image drawBuffer; // = null
        
The drawing buffer as a volatile image

/**
         * The drawing buffer as a volatile image
         */
        protected VolatileImage drawVBuffer; // = null
        
Whether or not the drawing buffer has been recently restored from
a lost state.

/**
         * Whether or not the drawing buffer has been recently restored from
         * a lost state.
         */
        protected boolean validatedContents; // = false

        /**
         * Size of the back buffers.  (Note: these fields were added in 6.0
         * but kept package-private to avoid exposing them in the spec.
         * None of these fields/methods really should have been marked
         * protected when they were introduced in 1.4, but now we just have
         * to live with that decision.)
         */

         
The width of the back buffers

/**
          * The width of the back buffers
          */
        private int width;

        
The height of the back buffers

/**
         * The height of the back buffers
         */
        private int height;

        
Creates a new flipping buffer strategy for this component. The component must be a Canvas or Window or Applet. 
Params:
  • numBuffers – the number of buffers
  • caps – the capabilities of the buffers
Throws:
See Also:
/**
         * Creates a new flipping buffer strategy for this component.
         * The component must be a {@code Canvas} or {@code Window} or
         * {@code Applet}.
         * @see Canvas
         * @see Window
         * @see Applet
         * @param numBuffers the number of buffers
         * @param caps the capabilities of the buffers
         * @exception AWTException if the capabilities supplied could not be
         * supported or met
         * @exception ClassCastException if the component is not a canvas or
         * window.
         * @exception IllegalStateException if the component has no peer
         * @exception IllegalArgumentException if {@code numBuffers} is less than two,
         * or if {@code BufferCapabilities.isPageFlipping} is not
         * {@code true}.
         * @see #createBuffers(int, BufferCapabilities)
         */
        @SuppressWarnings("deprecation")
        protected FlipBufferStrategy(int numBuffers, BufferCapabilities caps)
            throws AWTException
        {
            if (!(Component.this instanceof Window) &&
                !(Component.this instanceof Canvas) &&
                !(Component.this instanceof Applet))
            {
                throw new ClassCastException(
                        "Component must be a Canvas or Window or Applet");
            }
            this.numBuffers = numBuffers;
            this.caps = caps;
            createBuffers(numBuffers, caps);
        }

        
Creates one or more complex, flipping buffers with the given
capabilities.

Params:
  • numBuffers – number of buffers to create; must be greater than
one
  • caps – the capabilities of the buffers. BufferCapabilities.isPageFlipping must be true.
Throws:
See Also:
/**
         * Creates one or more complex, flipping buffers with the given
         * capabilities.
         * @param numBuffers number of buffers to create; must be greater than
         * one
         * @param caps the capabilities of the buffers.
         * {@code BufferCapabilities.isPageFlipping} must be
         * {@code true}.
         * @exception AWTException if the capabilities supplied could not be
         * supported or met
         * @exception IllegalStateException if the component has no peer
         * @exception IllegalArgumentException if numBuffers is less than two,
         * or if {@code BufferCapabilities.isPageFlipping} is not
         * {@code true}.
         * @see java.awt.BufferCapabilities#isPageFlipping()
         */
        protected void createBuffers(int numBuffers, BufferCapabilities caps)
            throws AWTException
        {
            if (numBuffers < 2) {
                throw new IllegalArgumentException(
                    "Number of buffers cannot be less than two");
            } else if (peer == null) {
                throw new IllegalStateException(
                    "Component must have a valid peer");
            } else if (caps == null || !caps.isPageFlipping()) {
                throw new IllegalArgumentException(
                    "Page flipping capabilities must be specified");
            }

            // save the current bounds
            width = getWidth();
            height = getHeight();

            if (drawBuffer != null) {
                // dispose the existing backbuffers
                invalidate();
                // ... then recreate the backbuffers
            }

            if (caps instanceof ExtendedBufferCapabilities) {
                ExtendedBufferCapabilities ebc =
                    (ExtendedBufferCapabilities)caps;
                if (ebc.getVSync() == VSYNC_ON) {
                    // if this buffer strategy is not allowed to be v-synced,
                    // change the caps that we pass to the peer but keep on
                    // trying to create v-synced buffers;
                    // do not throw IAE here in case it is disallowed, see
                    // ExtendedBufferCapabilities for more info
                    if (!VSyncedBSManager.vsyncAllowed(this)) {
                        caps = ebc.derive(VSYNC_DEFAULT);
                    }
                }
            }

            peer.createBuffers(numBuffers, caps);
            updateInternalBuffers();
        }

        
Updates internal buffers (both volatile and non-volatile)
by requesting the back-buffer from the peer.

/**
         * Updates internal buffers (both volatile and non-volatile)
         * by requesting the back-buffer from the peer.
         */
        private void updateInternalBuffers() {
            // get the images associated with the draw buffer
            drawBuffer = getBackBuffer();
            if (drawBuffer instanceof VolatileImage) {
                drawVBuffer = (VolatileImage)drawBuffer;
            } else {
                drawVBuffer = null;
            }
        }

        
Throws:
Returns:direct access to the back buffer, as an image.
/**
         * @return direct access to the back buffer, as an image.
         * @exception IllegalStateException if the buffers have not yet
         * been created
         */
        protected Image getBackBuffer() {
            if (peer != null) {
                return peer.getBackBuffer();
            } else {
                throw new IllegalStateException(
                    "Component must have a valid peer");
            }
        }

        
Flipping moves the contents of the back buffer to the front buffer,
either by copying or by moving the video pointer.

Params:
  • flipAction – an integer value describing the flipping action for the contents of the back buffer. This should be one of the values of the BufferCapabilities.FlipContents property.
Throws:
See Also:
/**
         * Flipping moves the contents of the back buffer to the front buffer,
         * either by copying or by moving the video pointer.
         * @param flipAction an integer value describing the flipping action
         * for the contents of the back buffer.  This should be one of the
         * values of the {@code BufferCapabilities.FlipContents}
         * property.
         * @exception IllegalStateException if the buffers have not yet
         * been created
         * @see java.awt.BufferCapabilities#getFlipContents()
         */
        protected void flip(BufferCapabilities.FlipContents flipAction) {
            if (peer != null) {
                Image backBuffer = getBackBuffer();
                if (backBuffer != null) {
                    peer.flip(0, 0,
                              backBuffer.getWidth(null),
                              backBuffer.getHeight(null), flipAction);
                }
            } else {
                throw new IllegalStateException(
                    "Component must have a valid peer");
            }
        }

        void flipSubRegion(int x1, int y1, int x2, int y2,
                      BufferCapabilities.FlipContents flipAction)
        {
            if (peer != null) {
                peer.flip(x1, y1, x2, y2, flipAction);
            } else {
                throw new IllegalStateException(
                    "Component must have a valid peer");
            }
        }

        
Destroys the buffers and invalidates the state of FlipBufferStrategy.

/**
         * Destroys the buffers and invalidates the state of FlipBufferStrategy.
         */
        private void invalidate() {
            drawBuffer = null;
            drawVBuffer = null;
            destroyBuffers();
        }

        
Destroys the buffers created through this object

/**
         * Destroys the buffers created through this object
         */
        protected void destroyBuffers() {
            VSyncedBSManager.releaseVsync(this);
            if (peer != null) {
                peer.destroyBuffers();
            } else {
                throw new IllegalStateException(
                    "Component must have a valid peer");
            }
        }

        
Returns:the buffering capabilities of this strategy
/**
         * @return the buffering capabilities of this strategy
         */
        public BufferCapabilities getCapabilities() {
            if (caps instanceof ProxyCapabilities) {
                return ((ProxyCapabilities)caps).orig;
            } else {
                return caps;
            }
        }

        
Returns:the graphics on the drawing buffer.  This method may not
be synchronized for performance reasons; use of this method by multiple
threads should be handled at the application level.  Disposal of the
graphics object must be handled by the application.
/**
         * @return the graphics on the drawing buffer.  This method may not
         * be synchronized for performance reasons; use of this method by multiple
         * threads should be handled at the application level.  Disposal of the
         * graphics object must be handled by the application.
         */
        public Graphics getDrawGraphics() {
            revalidate();
            return drawBuffer.getGraphics();
        }

        
Restore the drawing buffer if it has been lost

/**
         * Restore the drawing buffer if it has been lost
         */
        protected void revalidate() {
            validatedContents = false;
            if (getWidth() != width || getHeight() != height
                    || drawBuffer == null) {
                // component has been resized or the peer was recreated;
                // recreate the backbuffers
                try {
                    createBuffers(numBuffers, caps);
                } catch (AWTException e) {
                    // shouldn't be possible
                }
                validatedContents = true;
            }

            // get the buffers from the peer every time since they
            // might have been replaced in response to a display change event
            updateInternalBuffers();

            // now validate the backbuffer
            if (drawVBuffer != null) {
                GraphicsConfiguration gc =
                        getGraphicsConfiguration_NoClientCode();
                int returnCode = drawVBuffer.validate(gc);
                if (returnCode == VolatileImage.IMAGE_INCOMPATIBLE) {
                    try {
                        createBuffers(numBuffers, caps);
                    } catch (AWTException e) {
                        // shouldn't be possible
                    }
                    if (drawVBuffer != null) {
                        // backbuffers were recreated, so validate again
                        drawVBuffer.validate(gc);
                    }
                    validatedContents = true;
                } else if (returnCode == VolatileImage.IMAGE_RESTORED) {
                    validatedContents = true;
                }
            }
        }

        
Returns:whether the drawing buffer was lost since the last call to getDrawGraphics
/**
         * @return whether the drawing buffer was lost since the last call to
         * {@code getDrawGraphics}
         */
        public boolean contentsLost() {
            if (drawVBuffer == null) {
                return false;
            }
            return drawVBuffer.contentsLost();
        }

        
Returns:whether the drawing buffer was recently restored from a lost
state and reinitialized to the default background color (white)
/**
         * @return whether the drawing buffer was recently restored from a lost
         * state and reinitialized to the default background color (white)
         */
        public boolean contentsRestored() {
            return validatedContents;
        }

        
Makes the next available buffer visible by either blitting or
flipping.

/**
         * Makes the next available buffer visible by either blitting or
         * flipping.
         */
        public void show() {
            flip(caps.getFlipContents());
        }

        
Makes specified region of the next available buffer visible
by either blitting or flipping.

/**
         * Makes specified region of the next available buffer visible
         * by either blitting or flipping.
         */
        void showSubRegion(int x1, int y1, int x2, int y2) {
            flipSubRegion(x1, y1, x2, y2, caps.getFlipContents());
        }

        
{@inheritDoc}

Since:1.6
/**
         * {@inheritDoc}
         * @since 1.6
         */
        public void dispose() {
            if (Component.this.bufferStrategy == this) {
                Component.this.bufferStrategy = null;
                if (peer != null) {
                    invalidate();
                }
            }
        }

    } // Inner class FlipBufferStrategy

    
Inner class for blitting offscreen surfaces to a component.

Author:Michael Martak
Since:1.4
/**
     * Inner class for blitting offscreen surfaces to a component.
     *
     * @author Michael Martak
     * @since 1.4
     */
    protected class BltBufferStrategy extends BufferStrategy {

        
The buffering capabilities

/**
         * The buffering capabilities
         */
        protected BufferCapabilities caps; // = null
        
The back buffers

/**
         * The back buffers
         */
        protected VolatileImage[] backBuffers; // = null
        
Whether or not the drawing buffer has been recently restored from
a lost state.

/**
         * Whether or not the drawing buffer has been recently restored from
         * a lost state.
         */
        protected boolean validatedContents; // = false
        
Width of the back buffers

/**
         * Width of the back buffers
         */
        protected int width;
        
Height of the back buffers

/**
         * Height of the back buffers
         */
        protected int height;

        
Insets for the hosting Component.  The size of the back buffer
is constrained by these.

/**
         * Insets for the hosting Component.  The size of the back buffer
         * is constrained by these.
         */
        private Insets insets;

        
Creates a new blt buffer strategy around a component

Params:
  • numBuffers – number of buffers to create, including the
front buffer
  • caps – the capabilities of the buffers
/**
         * Creates a new blt buffer strategy around a component
         * @param numBuffers number of buffers to create, including the
         * front buffer
         * @param caps the capabilities of the buffers
         */
        protected BltBufferStrategy(int numBuffers, BufferCapabilities caps) {
            this.caps = caps;
            createBackBuffers(numBuffers - 1);
        }

        
{@inheritDoc}

Since:1.6
/**
         * {@inheritDoc}
         * @since 1.6
         */
        public void dispose() {
            if (backBuffers != null) {
                for (int counter = backBuffers.length - 1; counter >= 0;
                     counter--) {
                    if (backBuffers[counter] != null) {
                        backBuffers[counter].flush();
                        backBuffers[counter] = null;
                    }
                }
            }
            if (Component.this.bufferStrategy == this) {
                Component.this.bufferStrategy = null;
            }
        }

        
Creates the back buffers

Params:
  • numBuffers – the number of buffers to create
/**
         * Creates the back buffers
         *
         * @param numBuffers the number of buffers to create
         */
        protected void createBackBuffers(int numBuffers) {
            if (numBuffers == 0) {
                backBuffers = null;
            } else {
                // save the current bounds
                width = getWidth();
                height = getHeight();
                insets = getInsets_NoClientCode();
                int iWidth = width - insets.left - insets.right;
                int iHeight = height - insets.top - insets.bottom;

                // It is possible for the component's width and/or height
                // to be 0 here.  Force the size of the backbuffers to
                // be > 0 so that creating the image won't fail.
                iWidth = Math.max(1, iWidth);
                iHeight = Math.max(1, iHeight);
                if (backBuffers == null) {
                    backBuffers = new VolatileImage[numBuffers];
                } else {
                    // flush any existing backbuffers
                    for (int i = 0; i < numBuffers; i++) {
                        if (backBuffers[i] != null) {
                            backBuffers[i].flush();
                            backBuffers[i] = null;
                        }
                    }
                }

                // create the backbuffers
                for (int i = 0; i < numBuffers; i++) {
                    backBuffers[i] = createVolatileImage(iWidth, iHeight);
                }
            }
        }

        
Returns:the buffering capabilities of this strategy
/**
         * @return the buffering capabilities of this strategy
         */
        public BufferCapabilities getCapabilities() {
            return caps;
        }

        
Returns:the draw graphics
/**
         * @return the draw graphics
         */
        public Graphics getDrawGraphics() {
            revalidate();
            Image backBuffer = getBackBuffer();
            if (backBuffer == null) {
                return getGraphics();
            }
            SunGraphics2D g = (SunGraphics2D)backBuffer.getGraphics();
            g.constrain(-insets.left, -insets.top,
                        backBuffer.getWidth(null) + insets.left,
                        backBuffer.getHeight(null) + insets.top);
            return g;
        }

        
Returns:direct access to the back buffer, as an image.
If there is no back buffer, returns null.
/**
         * @return direct access to the back buffer, as an image.
         * If there is no back buffer, returns null.
         */
        Image getBackBuffer() {
            if (backBuffers != null) {
                return backBuffers[backBuffers.length - 1];
            } else {
                return null;
            }
        }

        
Makes the next available buffer visible.

/**
         * Makes the next available buffer visible.
         */
        public void show() {
            showSubRegion(insets.left, insets.top,
                          width - insets.right,
                          height - insets.bottom);
        }

        
Package-private method to present a specific rectangular area
of this buffer.  This class currently shows only the entire
buffer, by calling showSubRegion() with the full dimensions of
the buffer.  Subclasses (e.g., BltSubRegionBufferStrategy
and FlipSubRegionBufferStrategy) may have region-specific show
methods that call this method with actual sub regions of the
buffer.

/**
         * Package-private method to present a specific rectangular area
         * of this buffer.  This class currently shows only the entire
         * buffer, by calling showSubRegion() with the full dimensions of
         * the buffer.  Subclasses (e.g., BltSubRegionBufferStrategy
         * and FlipSubRegionBufferStrategy) may have region-specific show
         * methods that call this method with actual sub regions of the
         * buffer.
         */
        void showSubRegion(int x1, int y1, int x2, int y2) {
            if (backBuffers == null) {
                return;
            }
            // Adjust location to be relative to client area.
            x1 -= insets.left;
            x2 -= insets.left;
            y1 -= insets.top;
            y2 -= insets.top;
            Graphics g = getGraphics_NoClientCode();
            if (g == null) {
                // Not showing, bail
                return;
            }
            try {
                // First image copy is in terms of Frame's coordinates, need
                // to translate to client area.
                g.translate(insets.left, insets.top);
                for (int i = 0; i < backBuffers.length; i++) {
                    g.drawImage(backBuffers[i],
                                x1, y1, x2, y2,
                                x1, y1, x2, y2,
                                null);
                    g.dispose();
                    g = null;
                    g = backBuffers[i].getGraphics();
                }
            } finally {
                if (g != null) {
                    g.dispose();
                }
            }
        }

        
Restore the drawing buffer if it has been lost

/**
         * Restore the drawing buffer if it has been lost
         */
        protected void revalidate() {
            revalidate(true);
        }

        void revalidate(boolean checkSize) {
            validatedContents = false;

            if (backBuffers == null) {
                return;
            }

            if (checkSize) {
                Insets insets = getInsets_NoClientCode();
                if (getWidth() != width || getHeight() != height ||
                    !insets.equals(this.insets)) {
                    // component has been resized; recreate the backbuffers
                    createBackBuffers(backBuffers.length);
                    validatedContents = true;
                }
            }

            // now validate the backbuffer
            GraphicsConfiguration gc = getGraphicsConfiguration_NoClientCode();
            int returnCode =
                backBuffers[backBuffers.length - 1].validate(gc);
            if (returnCode == VolatileImage.IMAGE_INCOMPATIBLE) {
                if (checkSize) {
                    createBackBuffers(backBuffers.length);
                    // backbuffers were recreated, so validate again
                    backBuffers[backBuffers.length - 1].validate(gc);
                }
                // else case means we're called from Swing on the toolkit
                // thread, don't recreate buffers as that'll deadlock
                // (creating VolatileImages invokes getting GraphicsConfig
                // which grabs treelock).
                validatedContents = true;
            } else if (returnCode == VolatileImage.IMAGE_RESTORED) {
                validatedContents = true;
            }
        }

        
Returns:whether the drawing buffer was lost since the last call to getDrawGraphics
/**
         * @return whether the drawing buffer was lost since the last call to
         * {@code getDrawGraphics}
         */
        public boolean contentsLost() {
            if (backBuffers == null) {
                return false;
            } else {
                return backBuffers[backBuffers.length - 1].contentsLost();
            }
        }

        
Returns:whether the drawing buffer was recently restored from a lost
state and reinitialized to the default background color (white)
/**
         * @return whether the drawing buffer was recently restored from a lost
         * state and reinitialized to the default background color (white)
         */
        public boolean contentsRestored() {
            return validatedContents;
        }
    } // Inner class BltBufferStrategy

    
Private class to perform sub-region flipping.

/**
     * Private class to perform sub-region flipping.
     */
    private class FlipSubRegionBufferStrategy extends FlipBufferStrategy
        implements SubRegionShowable
    {

        protected FlipSubRegionBufferStrategy(int numBuffers,
                                              BufferCapabilities caps)
            throws AWTException
        {
            super(numBuffers, caps);
        }

        public void show(int x1, int y1, int x2, int y2) {
            showSubRegion(x1, y1, x2, y2);
        }

        // This is invoked by Swing on the toolkit thread.
        public boolean showIfNotLost(int x1, int y1, int x2, int y2) {
            if (!contentsLost()) {
                showSubRegion(x1, y1, x2, y2);
                return !contentsLost();
            }
            return false;
        }
    }

    
Private class to perform sub-region blitting.  Swing will use
this subclass via the SubRegionShowable interface in order to
copy only the area changed during a repaint.
See javax.swing.BufferStrategyPaintManager.

/**
     * Private class to perform sub-region blitting.  Swing will use
     * this subclass via the SubRegionShowable interface in order to
     * copy only the area changed during a repaint.
     * See javax.swing.BufferStrategyPaintManager.
     */
    private class BltSubRegionBufferStrategy extends BltBufferStrategy
        implements SubRegionShowable
    {

        protected BltSubRegionBufferStrategy(int numBuffers,
                                             BufferCapabilities caps)
        {
            super(numBuffers, caps);
        }

        public void show(int x1, int y1, int x2, int y2) {
            showSubRegion(x1, y1, x2, y2);
        }

        // This method is called by Swing on the toolkit thread.
        public boolean showIfNotLost(int x1, int y1, int x2, int y2) {
            if (!contentsLost()) {
                showSubRegion(x1, y1, x2, y2);
                return !contentsLost();
            }
            return false;
        }
    }

    
Inner class for flipping buffers on a component. That component must be a Canvas or Window. 
Author:Michael Martak
See Also:
Since:1.4
/**
     * Inner class for flipping buffers on a component.  That component must
     * be a {@code Canvas} or {@code Window}.
     * @see Canvas
     * @see Window
     * @see java.awt.image.BufferStrategy
     * @author Michael Martak
     * @since 1.4
     */
    private class SingleBufferStrategy extends BufferStrategy {

        private BufferCapabilities caps;

        public SingleBufferStrategy(BufferCapabilities caps) {
            this.caps = caps;
        }
        public BufferCapabilities getCapabilities() {
            return caps;
        }
        public Graphics getDrawGraphics() {
            return getGraphics();
        }
        public boolean contentsLost() {
            return false;
        }
        public boolean contentsRestored() {
            return false;
        }
        public void show() {
            // Do nothing
        }
    } // Inner class SingleBufferStrategy

    
Sets whether or not paint messages received from the operating system
should be ignored.  This does not affect paint events generated in
software by the AWT, unless they are an immediate response to an
OS-level paint message.


This is useful, for example, if running under full-screen mode and
better performance is desired, or if page-flipping is used as the
buffer strategy.

Params:
  • ignoreRepaint – true if the paint messages from the OS should be ignored; otherwise false
See Also:
Since:1.4
/**
     * Sets whether or not paint messages received from the operating system
     * should be ignored.  This does not affect paint events generated in
     * software by the AWT, unless they are an immediate response to an
     * OS-level paint message.
     * <p>
     * This is useful, for example, if running under full-screen mode and
     * better performance is desired, or if page-flipping is used as the
     * buffer strategy.
     *
     * @param ignoreRepaint {@code true} if the paint messages from the OS
     *                      should be ignored; otherwise {@code false}
     *
     * @since 1.4
     * @see #getIgnoreRepaint
     * @see Canvas#createBufferStrategy
     * @see Window#createBufferStrategy
     * @see java.awt.image.BufferStrategy
     * @see GraphicsDevice#setFullScreenWindow
     */
    public void setIgnoreRepaint(boolean ignoreRepaint) {
        this.ignoreRepaint = ignoreRepaint;
    }

    
See Also:
Returns:whether or not paint messages received from the operating system
should be ignored.
Since:1.4
/**
     * @return whether or not paint messages received from the operating system
     * should be ignored.
     *
     * @since 1.4
     * @see #setIgnoreRepaint
     */
    public boolean getIgnoreRepaint() {
        return ignoreRepaint;
    }

    
Checks whether this component "contains" the specified point, where x and y are defined to be relative to the coordinate system of this component. 
Params:
  • x –   the x coordinate of the point
  • y –   the y coordinate of the point
See Also:
Returns:true if the point is within the component; otherwise false
Since:    1.1
/**
     * Checks whether this component "contains" the specified point,
     * where {@code x} and {@code y} are defined to be
     * relative to the coordinate system of this component.
     *
     * @param     x   the <i>x</i> coordinate of the point
     * @param     y   the <i>y</i> coordinate of the point
     * @return {@code true} if the point is within the component;
     *         otherwise {@code false}
     * @see       #getComponentAt(int, int)
     * @since     1.1
     */
    public boolean contains(int x, int y) {
        return inside(x, y);
    }

    
Checks whether the point is inside of this component.

Params:
  • x – the x coordinate of the point
  • y – the y coordinate of the point
Returns:true if the point is within the component; otherwise false
Deprecated:As of JDK version 1.1,
replaced by contains(int, int).
/**
     * Checks whether the point is inside of this component.
     *
     * @param  x the <i>x</i> coordinate of the point
     * @param  y the <i>y</i> coordinate of the point
     * @return {@code true} if the point is within the component;
     *         otherwise {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by contains(int, int).
     */
    @Deprecated
    public boolean inside(int x, int y) {
        return (x >= 0) && (x < width) && (y >= 0) && (y < height);
    }

    
Checks whether this component "contains" the specified point,
where the point's x and y coordinates are defined
to be relative to the coordinate system of this component.

Params:
  • p –     the point
Throws:
See Also:
Returns:true if the point is within the component; otherwise false
Since:    1.1
/**
     * Checks whether this component "contains" the specified point,
     * where the point's <i>x</i> and <i>y</i> coordinates are defined
     * to be relative to the coordinate system of this component.
     *
     * @param     p     the point
     * @return {@code true} if the point is within the component;
     *         otherwise {@code false}
     * @throws    NullPointerException if {@code p} is {@code null}
     * @see       #getComponentAt(Point)
     * @since     1.1
     */
    public boolean contains(Point p) {
        return contains(p.x, p.y);
    }

    
Determines if this component or one of its immediate
subcomponents contains the (x, y) location,
and if so, returns the containing component. This method only
looks one level deep. If the point (x, y) is
inside a subcomponent that itself has subcomponents, it does not
go looking down the subcomponent tree.

 The locate method of Component simply returns the component itself if the (x, y) coordinate location is inside its bounding box, and null otherwise. 
Params:
  • x –   the x coordinate
  • y –   the y coordinate
See Also:
Returns:   the component or subcomponent that contains the
               (x, y) location; null if the location is outside this component
Since:    1.0
/**
     * Determines if this component or one of its immediate
     * subcomponents contains the (<i>x</i>,&nbsp;<i>y</i>) location,
     * and if so, returns the containing component. This method only
     * looks one level deep. If the point (<i>x</i>,&nbsp;<i>y</i>) is
     * inside a subcomponent that itself has subcomponents, it does not
     * go looking down the subcomponent tree.
     * <p>
     * The {@code locate} method of {@code Component} simply
     * returns the component itself if the (<i>x</i>,&nbsp;<i>y</i>)
     * coordinate location is inside its bounding box, and {@code null}
     * otherwise.
     * @param     x   the <i>x</i> coordinate
     * @param     y   the <i>y</i> coordinate
     * @return    the component or subcomponent that contains the
     *                (<i>x</i>,&nbsp;<i>y</i>) location;
     *                {@code null} if the location
     *                is outside this component
     * @see       #contains(int, int)
     * @since     1.0
     */
    public Component getComponentAt(int x, int y) {
        return locate(x, y);
    }

    
Returns the component occupying the position specified (this component,
or immediate child component, or null if neither
of the first two occupies the location).

Params:
  • x – the x coordinate to search for components at
  • y – the y coordinate to search for components at
Returns:the component at the specified location or null
Deprecated:As of JDK version 1.1,
replaced by getComponentAt(int, int).
/**
     * Returns the component occupying the position specified (this component,
     * or immediate child component, or null if neither
     * of the first two occupies the location).
     *
     * @param  x the <i>x</i> coordinate to search for components at
     * @param  y the <i>y</i> coordinate to search for components at
     * @return the component at the specified location or {@code null}
     * @deprecated As of JDK version 1.1,
     * replaced by getComponentAt(int, int).
     */
    @Deprecated
    public Component locate(int x, int y) {
        return contains(x, y) ? this : null;
    }

    
Returns the component or subcomponent that contains the
specified point.

Params:
  • p – the point
See Also:
Returns:the component at the specified location or null
Since:1.1
/**
     * Returns the component or subcomponent that contains the
     * specified point.
     * @param  p the point
     * @return the component at the specified location or {@code null}
     * @see java.awt.Component#contains
     * @since 1.1
     */
    public Component getComponentAt(Point p) {
        return getComponentAt(p.x, p.y);
    }

    
Params:
  • e – the event to deliver
Deprecated:As of JDK version 1.1, replaced by dispatchEvent(AWTEvent e).
/**
     * @param  e the event to deliver
     * @deprecated As of JDK version 1.1,
     * replaced by {@code dispatchEvent(AWTEvent e)}.
     */
    @Deprecated
    public void deliverEvent(Event e) {
        postEvent(e);
    }

    
Dispatches an event to this component or one of its sub components. Calls processEvent before returning for 1.1-style events which have been enabled for the Component. 
Params:
  • e – the event
/**
     * Dispatches an event to this component or one of its sub components.
     * Calls {@code processEvent} before returning for 1.1-style
     * events which have been enabled for the {@code Component}.
     * @param e the event
     */
    public final void dispatchEvent(AWTEvent e) {
        dispatchEventImpl(e);
    }

    @SuppressWarnings("deprecation")
    void dispatchEventImpl(AWTEvent e) {
        int id = e.getID();

        // Check that this component belongs to this app-context
        AppContext compContext = appContext;
        if (compContext != null && !compContext.equals(AppContext.getAppContext())) {
            if (eventLog.isLoggable(PlatformLogger.Level.FINE)) {
                eventLog.fine("Event " + e + " is being dispatched on the wrong AppContext");
            }
        }

        if (eventLog.isLoggable(PlatformLogger.Level.FINEST)) {
            eventLog.finest("{0}", e);
        }

        /*
         * 0. Set timestamp and modifiers of current event.
         */
        if (!(e instanceof KeyEvent)) {
            // Timestamp of a key event is set later in DKFM.preDispatchKeyEvent(KeyEvent).
            EventQueue.setCurrentEventAndMostRecentTime(e);
        }

        /*
         * 1. Pre-dispatchers. Do any necessary retargeting/reordering here
         *    before we notify AWTEventListeners.
         */

        if (e instanceof SunDropTargetEvent) {
            ((SunDropTargetEvent)e).dispatch();
            return;
        }

        if (!e.focusManagerIsDispatching) {
            // Invoke the private focus retargeting method which provides
            // lightweight Component support
            if (e.isPosted) {
                e = KeyboardFocusManager.retargetFocusEvent(e);
                e.isPosted = true;
            }

            // Now, with the event properly targeted to a lightweight
            // descendant if necessary, invoke the public focus retargeting
            // and dispatching function
            if (KeyboardFocusManager.getCurrentKeyboardFocusManager().
                dispatchEvent(e))
            {
                return;
            }
        }
        if ((e instanceof FocusEvent) && focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
            focusLog.finest("" + e);
        }
        // MouseWheel may need to be retargeted here so that
        // AWTEventListener sees the event go to the correct
        // Component.  If the MouseWheelEvent needs to go to an ancestor,
        // the event is dispatched to the ancestor, and dispatching here
        // stops.
        if (id == MouseEvent.MOUSE_WHEEL &&
            (!eventTypeEnabled(id)) &&
            (peer != null && !peer.handlesWheelScrolling()) &&
            (dispatchMouseWheelToAncestor((MouseWheelEvent)e)))
        {
            return;
        }

        /*
         * 2. Allow the Toolkit to pass this to AWTEventListeners.
         */
        Toolkit toolkit = Toolkit.getDefaultToolkit();
        toolkit.notifyAWTEventListeners(e);


        /*
         * 3. If no one has consumed a key event, allow the
         *    KeyboardFocusManager to process it.
         */
        if (!e.isConsumed()) {
            if (e instanceof java.awt.event.KeyEvent) {
                KeyboardFocusManager.getCurrentKeyboardFocusManager().
                    processKeyEvent(this, (KeyEvent)e);
                if (e.isConsumed()) {
                    return;
                }
            }
        }

        /*
         * 4. Allow input methods to process the event
         */
        if (areInputMethodsEnabled()) {
            // We need to pass on InputMethodEvents since some host
            // input method adapters send them through the Java
            // event queue instead of directly to the component,
            // and the input context also handles the Java composition window
            if(((e instanceof InputMethodEvent) && !(this instanceof CompositionArea))
               ||
               // Otherwise, we only pass on input and focus events, because
               // a) input methods shouldn't know about semantic or component-level events
               // b) passing on the events takes time
               // c) isConsumed() is always true for semantic events.
               (e instanceof InputEvent) || (e instanceof FocusEvent)) {
                InputContext inputContext = getInputContext();


                if (inputContext != null) {
                    inputContext.dispatchEvent(e);
                    if (e.isConsumed()) {
                        if ((e instanceof FocusEvent) && focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                            focusLog.finest("3579: Skipping " + e);
                        }
                        return;
                    }
                }
            }
        } else {
            // When non-clients get focus, we need to explicitly disable the native
            // input method. The native input method is actually not disabled when
            // the active/passive/peered clients loose focus.
            if (id == FocusEvent.FOCUS_GAINED) {
                InputContext inputContext = getInputContext();
                if (inputContext != null && inputContext instanceof sun.awt.im.InputContext) {
                    ((sun.awt.im.InputContext)inputContext).disableNativeIM();
                }
            }
        }


        /*
         * 5. Pre-process any special events before delivery
         */
        switch(id) {
            // Handling of the PAINT and UPDATE events is now done in the
            // peer's handleEvent() method so the background can be cleared
            // selectively for non-native components on Windows only.
            // - Fred.Ecks@Eng.sun.com, 5-8-98

          case KeyEvent.KEY_PRESSED:
          case KeyEvent.KEY_RELEASED:
              Container p = (Container)((this instanceof Container) ? this : parent);
              if (p != null) {
                  p.preProcessKeyEvent((KeyEvent)e);
                  if (e.isConsumed()) {
                        if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                            focusLog.finest("Pre-process consumed event");
                        }
                      return;
                  }
              }
              break;

          default:
              break;
        }

        /*
         * 6. Deliver event for normal processing
         */
        if (newEventsOnly) {
            // Filtering needs to really be moved to happen at a lower
            // level in order to get maximum performance gain;  it is
            // here temporarily to ensure the API spec is honored.
            //
            if (eventEnabled(e)) {
                processEvent(e);
            }
        } else if (id == MouseEvent.MOUSE_WHEEL) {
            // newEventsOnly will be false for a listenerless ScrollPane, but
            // MouseWheelEvents still need to be dispatched to it so scrolling
            // can be done.
            autoProcessMouseWheel((MouseWheelEvent)e);
        } else if (!(e instanceof MouseEvent && !postsOldMouseEvents())) {
            //
            // backward compatibility
            //
            Event olde = e.convertToOld();
            if (olde != null) {
                int key = olde.key;
                int modifiers = olde.modifiers;

                postEvent(olde);
                if (olde.isConsumed()) {
                    e.consume();
                }
                // if target changed key or modifier values, copy them
                // back to original event
                //
                switch(olde.id) {
                  case Event.KEY_PRESS:
                  case Event.KEY_RELEASE:
                  case Event.KEY_ACTION:
                  case Event.KEY_ACTION_RELEASE:
                      if (olde.key != key) {
                          ((KeyEvent)e).setKeyChar(olde.getKeyEventChar());
                      }
                      if (olde.modifiers != modifiers) {
                          ((KeyEvent)e).setModifiers(olde.modifiers);
                      }
                      break;
                  default:
                      break;
                }
            }
        }

        /*
         * 9. Allow the peer to process the event.
         * Except KeyEvents, they will be processed by peer after
         * all KeyEventPostProcessors
         * (see DefaultKeyboardFocusManager.dispatchKeyEvent())
         */
        if (!(e instanceof KeyEvent)) {
            ComponentPeer tpeer = peer;
            if (e instanceof FocusEvent && (tpeer == null || tpeer instanceof LightweightPeer)) {
                // if focus owner is lightweight then its native container
                // processes event
                Component source = (Component)e.getSource();
                if (source != null) {
                    Container target = source.getNativeContainer();
                    if (target != null) {
                        tpeer = target.peer;
                    }
                }
            }
            if (tpeer != null) {
                tpeer.handleEvent(e);
            }
        }

        if (SunToolkit.isTouchKeyboardAutoShowEnabled() &&
            (toolkit instanceof SunToolkit) &&
            ((e instanceof MouseEvent) || (e instanceof FocusEvent))) {
            ((SunToolkit)toolkit).showOrHideTouchKeyboard(this, e);
        }
    } // dispatchEventImpl()

    /*
     * If newEventsOnly is false, method is called so that ScrollPane can
     * override it and handle common-case mouse wheel scrolling.  NOP
     * for Component.
     */
    void autoProcessMouseWheel(MouseWheelEvent e) {}

    /*
     * Dispatch given MouseWheelEvent to the first ancestor for which
     * MouseWheelEvents are enabled.
     *
     * Returns whether or not event was dispatched to an ancestor
     */
    @SuppressWarnings("deprecation")
    boolean dispatchMouseWheelToAncestor(MouseWheelEvent e) {
        int newX, newY;
        newX = e.getX() + getX(); // Coordinates take into account at least
        newY = e.getY() + getY(); // the cursor's position relative to this
                                  // Component (e.getX()), and this Component's
                                  // position relative to its parent.
        MouseWheelEvent newMWE;

        if (eventLog.isLoggable(PlatformLogger.Level.FINEST)) {
            eventLog.finest("dispatchMouseWheelToAncestor");
            eventLog.finest("orig event src is of " + e.getSource().getClass());
        }

        /* parent field for Window refers to the owning Window.
         * MouseWheelEvents should NOT be propagated into owning Windows
         */
        synchronized (getTreeLock()) {
            Container anc = getParent();
            while (anc != null && !anc.eventEnabled(e)) {
                // fix coordinates to be relative to new event source
                newX += anc.getX();
                newY += anc.getY();

                if (!(anc instanceof Window)) {
                    anc = anc.getParent();
                }
                else {
                    break;
                }
            }

            if (eventLog.isLoggable(PlatformLogger.Level.FINEST)) {
                eventLog.finest("new event src is " + anc.getClass());
            }

            if (anc != null && anc.eventEnabled(e)) {
                // Change event to be from new source, with new x,y
                // For now, just create a new event - yucky

                newMWE = new MouseWheelEvent(anc, // new source
                                             e.getID(),
                                             e.getWhen(),
                                             e.getModifiers(),
                                             newX, // x relative to new source
                                             newY, // y relative to new source
                                             e.getXOnScreen(),
                                             e.getYOnScreen(),
                                             e.getClickCount(),
                                             e.isPopupTrigger(),
                                             e.getScrollType(),
                                             e.getScrollAmount(),
                                             e.getWheelRotation(),
                                             e.getPreciseWheelRotation());
                ((AWTEvent)e).copyPrivateDataInto(newMWE);
                // When dispatching a wheel event to
                // ancestor, there is no need trying to find descendant
                // lightweights to dispatch event to.
                // If we dispatch the event to toplevel ancestor,
                // this could enclose the loop: 6480024.
                anc.dispatchEventToSelf(newMWE);
                if (newMWE.isConsumed()) {
                    e.consume();
                }
                return true;
            }
        }
        return false;
    }

    boolean areInputMethodsEnabled() {
        // in 1.2, we assume input method support is required for all
        // components that handle key events, but components can turn off
        // input methods by calling enableInputMethods(false).
        return ((eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0) &&
            ((eventMask & AWTEvent.KEY_EVENT_MASK) != 0 || keyListener != null);
    }

    // REMIND: remove when filtering is handled at lower level
    boolean eventEnabled(AWTEvent e) {
        return eventTypeEnabled(e.id);
    }

    boolean eventTypeEnabled(int type) {
        switch(type) {
          case ComponentEvent.COMPONENT_MOVED:
          case ComponentEvent.COMPONENT_RESIZED:
          case ComponentEvent.COMPONENT_SHOWN:
          case ComponentEvent.COMPONENT_HIDDEN:
              if ((eventMask & AWTEvent.COMPONENT_EVENT_MASK) != 0 ||
                  componentListener != null) {
                  return true;
              }
              break;
          case FocusEvent.FOCUS_GAINED:
          case FocusEvent.FOCUS_LOST:
              if ((eventMask & AWTEvent.FOCUS_EVENT_MASK) != 0 ||
                  focusListener != null) {
                  return true;
              }
              break;
          case KeyEvent.KEY_PRESSED:
          case KeyEvent.KEY_RELEASED:
          case KeyEvent.KEY_TYPED:
              if ((eventMask & AWTEvent.KEY_EVENT_MASK) != 0 ||
                  keyListener != null) {
                  return true;
              }
              break;
          case MouseEvent.MOUSE_PRESSED:
          case MouseEvent.MOUSE_RELEASED:
          case MouseEvent.MOUSE_ENTERED:
          case MouseEvent.MOUSE_EXITED:
          case MouseEvent.MOUSE_CLICKED:
              if ((eventMask & AWTEvent.MOUSE_EVENT_MASK) != 0 ||
                  mouseListener != null) {
                  return true;
              }
              break;
          case MouseEvent.MOUSE_MOVED:
          case MouseEvent.MOUSE_DRAGGED:
              if ((eventMask & AWTEvent.MOUSE_MOTION_EVENT_MASK) != 0 ||
                  mouseMotionListener != null) {
                  return true;
              }
              break;
          case MouseEvent.MOUSE_WHEEL:
              if ((eventMask & AWTEvent.MOUSE_WHEEL_EVENT_MASK) != 0 ||
                  mouseWheelListener != null) {
                  return true;
              }
              break;
          case InputMethodEvent.INPUT_METHOD_TEXT_CHANGED:
          case InputMethodEvent.CARET_POSITION_CHANGED:
              if ((eventMask & AWTEvent.INPUT_METHOD_EVENT_MASK) != 0 ||
                  inputMethodListener != null) {
                  return true;
              }
              break;
          case HierarchyEvent.HIERARCHY_CHANGED:
              if ((eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0 ||
                  hierarchyListener != null) {
                  return true;
              }
              break;
          case HierarchyEvent.ANCESTOR_MOVED:
          case HierarchyEvent.ANCESTOR_RESIZED:
              if ((eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0 ||
                  hierarchyBoundsListener != null) {
                  return true;
              }
              break;
          case ActionEvent.ACTION_PERFORMED:
              if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0) {
                  return true;
              }
              break;
          case TextEvent.TEXT_VALUE_CHANGED:
              if ((eventMask & AWTEvent.TEXT_EVENT_MASK) != 0) {
                  return true;
              }
              break;
          case ItemEvent.ITEM_STATE_CHANGED:
              if ((eventMask & AWTEvent.ITEM_EVENT_MASK) != 0) {
                  return true;
              }
              break;
          case AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED:
              if ((eventMask & AWTEvent.ADJUSTMENT_EVENT_MASK) != 0) {
                  return true;
              }
              break;
          default:
              break;
        }
        //
        // Always pass on events defined by external programs.
        //
        if (type > AWTEvent.RESERVED_ID_MAX) {
            return true;
        }
        return false;
    }

    
Deprecated:As of JDK version 1.1,
replaced by dispatchEvent(AWTEvent).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by dispatchEvent(AWTEvent).
     */
    @Deprecated
    public boolean postEvent(Event e) {
        ComponentPeer peer = this.peer;

        if (handleEvent(e)) {
            e.consume();
            return true;
        }

        Component parent = this.parent;
        int eventx = e.x;
        int eventy = e.y;
        if (parent != null) {
            e.translate(x, y);
            if (parent.postEvent(e)) {
                e.consume();
                return true;
            }
            // restore coords
            e.x = eventx;
            e.y = eventy;
        }
        return false;
    }

    // Event source interfaces

    
Adds the specified component listener to receive component events from this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the component listener
See Also:
Since:   1.1
/**
     * Adds the specified component listener to receive component events from
     * this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the component listener
     * @see      java.awt.event.ComponentEvent
     * @see      java.awt.event.ComponentListener
     * @see      #removeComponentListener
     * @see      #getComponentListeners
     * @since    1.1
     */
    public synchronized void addComponentListener(ComponentListener l) {
        if (l == null) {
            return;
        }
        componentListener = AWTEventMulticaster.add(componentListener, l);
        newEventsOnly = true;
    }

    
Removes the specified component listener so that it no longer receives component events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the component listener
See Also:
Since:   1.1
/**
     * Removes the specified component listener so that it no longer
     * receives component events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     * @param    l   the component listener
     * @see      java.awt.event.ComponentEvent
     * @see      java.awt.event.ComponentListener
     * @see      #addComponentListener
     * @see      #getComponentListeners
     * @since    1.1
     */
    public synchronized void removeComponentListener(ComponentListener l) {
        if (l == null) {
            return;
        }
        componentListener = AWTEventMulticaster.remove(componentListener, l);
    }

    
Returns an array of all the component listeners
registered on this component.

See Also:
Returns:all ComponentListeners of this component or an empty array if no component listeners are currently registered
Since:1.4
/**
     * Returns an array of all the component listeners
     * registered on this component.
     *
     * @return all {@code ComponentListener}s of this component
     *         or an empty array if no component
     *         listeners are currently registered
     *
     * @see #addComponentListener
     * @see #removeComponentListener
     * @since 1.4
     */
    public synchronized ComponentListener[] getComponentListeners() {
        return getListeners(ComponentListener.class);
    }

    
Adds the specified focus listener to receive focus events from this component when this component gains input focus. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the focus listener
See Also:
Since:   1.1
/**
     * Adds the specified focus listener to receive focus events from
     * this component when this component gains input focus.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the focus listener
     * @see      java.awt.event.FocusEvent
     * @see      java.awt.event.FocusListener
     * @see      #removeFocusListener
     * @see      #getFocusListeners
     * @since    1.1
     */
    public synchronized void addFocusListener(FocusListener l) {
        if (l == null) {
            return;
        }
        focusListener = AWTEventMulticaster.add(focusListener, l);
        newEventsOnly = true;

        // if this is a lightweight component, enable focus events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(AWTEvent.FOCUS_EVENT_MASK);
        }
    }

    
Removes the specified focus listener so that it no longer receives focus events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the focus listener
See Also:
Since:   1.1
/**
     * Removes the specified focus listener so that it no longer
     * receives focus events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the focus listener
     * @see      java.awt.event.FocusEvent
     * @see      java.awt.event.FocusListener
     * @see      #addFocusListener
     * @see      #getFocusListeners
     * @since    1.1
     */
    public synchronized void removeFocusListener(FocusListener l) {
        if (l == null) {
            return;
        }
        focusListener = AWTEventMulticaster.remove(focusListener, l);
    }

    
Returns an array of all the focus listeners
registered on this component.

See Also:
Returns:all of this component's FocusListeners or an empty array if no component listeners are currently registered
Since:1.4
/**
     * Returns an array of all the focus listeners
     * registered on this component.
     *
     * @return all of this component's {@code FocusListener}s
     *         or an empty array if no component
     *         listeners are currently registered
     *
     * @see #addFocusListener
     * @see #removeFocusListener
     * @since 1.4
     */
    public synchronized FocusListener[] getFocusListeners() {
        return getListeners(FocusListener.class);
    }

    
Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the hierarchy listener
See Also:
Since:   1.3
/**
     * Adds the specified hierarchy listener to receive hierarchy changed
     * events from this component when the hierarchy to which this container
     * belongs changes.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the hierarchy listener
     * @see      java.awt.event.HierarchyEvent
     * @see      java.awt.event.HierarchyListener
     * @see      #removeHierarchyListener
     * @see      #getHierarchyListeners
     * @since    1.3
     */
    public void addHierarchyListener(HierarchyListener l) {
        if (l == null) {
            return;
        }
        boolean notifyAncestors;
        synchronized (this) {
            notifyAncestors =
                (hierarchyListener == null &&
                 (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) == 0);
            hierarchyListener = AWTEventMulticaster.add(hierarchyListener, l);
            notifyAncestors = (notifyAncestors && hierarchyListener != null);
            newEventsOnly = true;
        }
        if (notifyAncestors) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(AWTEvent.HIERARCHY_EVENT_MASK,
                                                1);
            }
        }
    }

    
Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the hierarchy listener
See Also:
Since:   1.3
/**
     * Removes the specified hierarchy listener so that it no longer
     * receives hierarchy changed events from this component. This method
     * performs no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the hierarchy listener
     * @see      java.awt.event.HierarchyEvent
     * @see      java.awt.event.HierarchyListener
     * @see      #addHierarchyListener
     * @see      #getHierarchyListeners
     * @since    1.3
     */
    public void removeHierarchyListener(HierarchyListener l) {
        if (l == null) {
            return;
        }
        boolean notifyAncestors;
        synchronized (this) {
            notifyAncestors =
                (hierarchyListener != null &&
                 (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) == 0);
            hierarchyListener =
                AWTEventMulticaster.remove(hierarchyListener, l);
            notifyAncestors = (notifyAncestors && hierarchyListener == null);
        }
        if (notifyAncestors) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(AWTEvent.HIERARCHY_EVENT_MASK,
                                                -1);
            }
        }
    }

    
Returns an array of all the hierarchy listeners
registered on this component.

See Also:
Returns:all of this component's HierarchyListeners or an empty array if no hierarchy listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the hierarchy listeners
     * registered on this component.
     *
     * @return all of this component's {@code HierarchyListener}s
     *         or an empty array if no hierarchy
     *         listeners are currently registered
     *
     * @see      #addHierarchyListener
     * @see      #removeHierarchyListener
     * @since    1.4
     */
    public synchronized HierarchyListener[] getHierarchyListeners() {
        return getListeners(HierarchyListener.class);
    }

    
Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the hierarchy bounds listener
See Also:
Since:   1.3
/**
     * Adds the specified hierarchy bounds listener to receive hierarchy
     * bounds events from this component when the hierarchy to which this
     * container belongs changes.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the hierarchy bounds listener
     * @see      java.awt.event.HierarchyEvent
     * @see      java.awt.event.HierarchyBoundsListener
     * @see      #removeHierarchyBoundsListener
     * @see      #getHierarchyBoundsListeners
     * @since    1.3
     */
    public void addHierarchyBoundsListener(HierarchyBoundsListener l) {
        if (l == null) {
            return;
        }
        boolean notifyAncestors;
        synchronized (this) {
            notifyAncestors =
                (hierarchyBoundsListener == null &&
                 (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) == 0);
            hierarchyBoundsListener =
                AWTEventMulticaster.add(hierarchyBoundsListener, l);
            notifyAncestors = (notifyAncestors &&
                               hierarchyBoundsListener != null);
            newEventsOnly = true;
        }
        if (notifyAncestors) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(
                                                AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK, 1);
            }
        }
    }

    
Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the hierarchy bounds listener
See Also:
Since:   1.3
/**
     * Removes the specified hierarchy bounds listener so that it no longer
     * receives hierarchy bounds events from this component. This method
     * performs no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the hierarchy bounds listener
     * @see      java.awt.event.HierarchyEvent
     * @see      java.awt.event.HierarchyBoundsListener
     * @see      #addHierarchyBoundsListener
     * @see      #getHierarchyBoundsListeners
     * @since    1.3
     */
    public void removeHierarchyBoundsListener(HierarchyBoundsListener l) {
        if (l == null) {
            return;
        }
        boolean notifyAncestors;
        synchronized (this) {
            notifyAncestors =
                (hierarchyBoundsListener != null &&
                 (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) == 0);
            hierarchyBoundsListener =
                AWTEventMulticaster.remove(hierarchyBoundsListener, l);
            notifyAncestors = (notifyAncestors &&
                               hierarchyBoundsListener == null);
        }
        if (notifyAncestors) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(
                                                AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK, -1);
            }
        }
    }

    // Should only be called while holding the tree lock
    int numListening(long mask) {
        // One mask or the other, but not neither or both.
        if (eventLog.isLoggable(PlatformLogger.Level.FINE)) {
            if ((mask != AWTEvent.HIERARCHY_EVENT_MASK) &&
                (mask != AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK))
            {
                eventLog.fine("Assertion failed");
            }
        }
        if ((mask == AWTEvent.HIERARCHY_EVENT_MASK &&
             (hierarchyListener != null ||
              (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0)) ||
            (mask == AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK &&
             (hierarchyBoundsListener != null ||
              (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0))) {
            return 1;
        } else {
            return 0;
        }
    }

    // Should only be called while holding tree lock
    int countHierarchyMembers() {
        return 1;
    }
    // Should only be called while holding the tree lock
    int createHierarchyEvents(int id, Component changed,
                              Container changedParent, long changeFlags,
                              boolean enabledOnToolkit) {
        switch (id) {
          case HierarchyEvent.HIERARCHY_CHANGED:
              if (hierarchyListener != null ||
                  (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0 ||
                  enabledOnToolkit) {
                  HierarchyEvent e = new HierarchyEvent(this, id, changed,
                                                        changedParent,
                                                        changeFlags);
                  dispatchEvent(e);
                  return 1;
              }
              break;
          case HierarchyEvent.ANCESTOR_MOVED:
          case HierarchyEvent.ANCESTOR_RESIZED:
              if (eventLog.isLoggable(PlatformLogger.Level.FINE)) {
                  if (changeFlags != 0) {
                      eventLog.fine("Assertion (changeFlags == 0) failed");
                  }
              }
              if (hierarchyBoundsListener != null ||
                  (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0 ||
                  enabledOnToolkit) {
                  HierarchyEvent e = new HierarchyEvent(this, id, changed,
                                                        changedParent);
                  dispatchEvent(e);
                  return 1;
              }
              break;
          default:
              // assert false
              if (eventLog.isLoggable(PlatformLogger.Level.FINE)) {
                  eventLog.fine("This code must never be reached");
              }
              break;
        }
        return 0;
    }

    
Returns an array of all the hierarchy bounds listeners
registered on this component.

See Also:
Returns:all of this component's HierarchyBoundsListeners or an empty array if no hierarchy bounds listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the hierarchy bounds listeners
     * registered on this component.
     *
     * @return all of this component's {@code HierarchyBoundsListener}s
     *         or an empty array if no hierarchy bounds
     *         listeners are currently registered
     *
     * @see      #addHierarchyBoundsListener
     * @see      #removeHierarchyBoundsListener
     * @since    1.4
     */
    public synchronized HierarchyBoundsListener[] getHierarchyBoundsListeners() {
        return getListeners(HierarchyBoundsListener.class);
    }

    /*
     * Should only be called while holding the tree lock.
     * It's added only for overriding in java.awt.Window
     * because parent in Window is owner.
     */
    void adjustListeningChildrenOnParent(long mask, int num) {
        if (parent != null) {
            parent.adjustListeningChildren(mask, num);
        }
    }

    
Adds the specified key listener to receive key events from
this component.
If l is null, no exception is thrown and no action is performed.

Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the key listener.
See Also:
Since:   1.1
/**
     * Adds the specified key listener to receive key events from
     * this component.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the key listener.
     * @see      java.awt.event.KeyEvent
     * @see      java.awt.event.KeyListener
     * @see      #removeKeyListener
     * @see      #getKeyListeners
     * @since    1.1
     */
    public synchronized void addKeyListener(KeyListener l) {
        if (l == null) {
            return;
        }
        keyListener = AWTEventMulticaster.add(keyListener, l);
        newEventsOnly = true;

        // if this is a lightweight component, enable key events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(AWTEvent.KEY_EVENT_MASK);
        }
    }

    
Removes the specified key listener so that it no longer receives key events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the key listener
See Also:
Since:   1.1
/**
     * Removes the specified key listener so that it no longer
     * receives key events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the key listener
     * @see      java.awt.event.KeyEvent
     * @see      java.awt.event.KeyListener
     * @see      #addKeyListener
     * @see      #getKeyListeners
     * @since    1.1
     */
    public synchronized void removeKeyListener(KeyListener l) {
        if (l == null) {
            return;
        }
        keyListener = AWTEventMulticaster.remove(keyListener, l);
    }

    
Returns an array of all the key listeners
registered on this component.

See Also:
Returns:all of this component's KeyListeners or an empty array if no key listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the key listeners
     * registered on this component.
     *
     * @return all of this component's {@code KeyListener}s
     *         or an empty array if no key
     *         listeners are currently registered
     *
     * @see      #addKeyListener
     * @see      #removeKeyListener
     * @since    1.4
     */
    public synchronized KeyListener[] getKeyListeners() {
        return getListeners(KeyListener.class);
    }

    
Adds the specified mouse listener to receive mouse events from this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse listener
See Also:
Since:   1.1
/**
     * Adds the specified mouse listener to receive mouse events from
     * this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse listener
     * @see      java.awt.event.MouseEvent
     * @see      java.awt.event.MouseListener
     * @see      #removeMouseListener
     * @see      #getMouseListeners
     * @since    1.1
     */
    public synchronized void addMouseListener(MouseListener l) {
        if (l == null) {
            return;
        }
        mouseListener = AWTEventMulticaster.add(mouseListener,l);
        newEventsOnly = true;

        // if this is a lightweight component, enable mouse events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(AWTEvent.MOUSE_EVENT_MASK);
        }
    }

    
Removes the specified mouse listener so that it no longer receives mouse events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse listener
See Also:
Since:   1.1
/**
     * Removes the specified mouse listener so that it no longer
     * receives mouse events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse listener
     * @see      java.awt.event.MouseEvent
     * @see      java.awt.event.MouseListener
     * @see      #addMouseListener
     * @see      #getMouseListeners
     * @since    1.1
     */
    public synchronized void removeMouseListener(MouseListener l) {
        if (l == null) {
            return;
        }
        mouseListener = AWTEventMulticaster.remove(mouseListener, l);
    }

    
Returns an array of all the mouse listeners
registered on this component.

See Also:
Returns:all of this component's MouseListeners or an empty array if no mouse listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the mouse listeners
     * registered on this component.
     *
     * @return all of this component's {@code MouseListener}s
     *         or an empty array if no mouse
     *         listeners are currently registered
     *
     * @see      #addMouseListener
     * @see      #removeMouseListener
     * @since    1.4
     */
    public synchronized MouseListener[] getMouseListeners() {
        return getListeners(MouseListener.class);
    }

    
Adds the specified mouse motion listener to receive mouse motion events from this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse motion listener
See Also:
Since:   1.1
/**
     * Adds the specified mouse motion listener to receive mouse motion
     * events from this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse motion listener
     * @see      java.awt.event.MouseEvent
     * @see      java.awt.event.MouseMotionListener
     * @see      #removeMouseMotionListener
     * @see      #getMouseMotionListeners
     * @since    1.1
     */
    public synchronized void addMouseMotionListener(MouseMotionListener l) {
        if (l == null) {
            return;
        }
        mouseMotionListener = AWTEventMulticaster.add(mouseMotionListener,l);
        newEventsOnly = true;

        // if this is a lightweight component, enable mouse events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(AWTEvent.MOUSE_MOTION_EVENT_MASK);
        }
    }

    
Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse motion listener
See Also:
Since:   1.1
/**
     * Removes the specified mouse motion listener so that it no longer
     * receives mouse motion events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse motion listener
     * @see      java.awt.event.MouseEvent
     * @see      java.awt.event.MouseMotionListener
     * @see      #addMouseMotionListener
     * @see      #getMouseMotionListeners
     * @since    1.1
     */
    public synchronized void removeMouseMotionListener(MouseMotionListener l) {
        if (l == null) {
            return;
        }
        mouseMotionListener = AWTEventMulticaster.remove(mouseMotionListener, l);
    }

    
Returns an array of all the mouse motion listeners
registered on this component.

See Also:
Returns:all of this component's MouseMotionListeners or an empty array if no mouse motion listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the mouse motion listeners
     * registered on this component.
     *
     * @return all of this component's {@code MouseMotionListener}s
     *         or an empty array if no mouse motion
     *         listeners are currently registered
     *
     * @see      #addMouseMotionListener
     * @see      #removeMouseMotionListener
     * @since    1.4
     */
    public synchronized MouseMotionListener[] getMouseMotionListeners() {
        return getListeners(MouseMotionListener.class);
    }

    
Adds the specified mouse wheel listener to receive mouse wheel events
from this component.  Containers also receive mouse wheel events from
sub-components.

 For information on how mouse wheel events are dispatched, see the class description for MouseWheelEvent. 
 If l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse wheel listener
See Also:
Since:   1.4
/**
     * Adds the specified mouse wheel listener to receive mouse wheel events
     * from this component.  Containers also receive mouse wheel events from
     * sub-components.
     * <p>
     * For information on how mouse wheel events are dispatched, see
     * the class description for {@link MouseWheelEvent}.
     * <p>
     * If l is {@code null}, no exception is thrown and no
     * action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse wheel listener
     * @see      java.awt.event.MouseWheelEvent
     * @see      java.awt.event.MouseWheelListener
     * @see      #removeMouseWheelListener
     * @see      #getMouseWheelListeners
     * @since    1.4
     */
    public synchronized void addMouseWheelListener(MouseWheelListener l) {
        if (l == null) {
            return;
        }
        mouseWheelListener = AWTEventMulticaster.add(mouseWheelListener,l);
        newEventsOnly = true;

        // if this is a lightweight component, enable mouse events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(AWTEvent.MOUSE_WHEEL_EVENT_MASK);
        }
    }

    
Removes the specified mouse wheel listener so that it no longer
receives mouse wheel events from this component. This method performs
no function, nor does it throw an exception, if the listener
specified by the argument was not previously added to this component.
If l is null, no exception is thrown and no action is performed.

Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the mouse wheel listener.
See Also:
Since:   1.4
/**
     * Removes the specified mouse wheel listener so that it no longer
     * receives mouse wheel events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the mouse wheel listener.
     * @see      java.awt.event.MouseWheelEvent
     * @see      java.awt.event.MouseWheelListener
     * @see      #addMouseWheelListener
     * @see      #getMouseWheelListeners
     * @since    1.4
     */
    public synchronized void removeMouseWheelListener(MouseWheelListener l) {
        if (l == null) {
            return;
        }
        mouseWheelListener = AWTEventMulticaster.remove(mouseWheelListener, l);
    }

    
Returns an array of all the mouse wheel listeners
registered on this component.

See Also:
Returns:all of this component's MouseWheelListeners or an empty array if no mouse wheel listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the mouse wheel listeners
     * registered on this component.
     *
     * @return all of this component's {@code MouseWheelListener}s
     *         or an empty array if no mouse wheel
     *         listeners are currently registered
     *
     * @see      #addMouseWheelListener
     * @see      #removeMouseWheelListener
     * @since    1.4
     */
    public synchronized MouseWheelListener[] getMouseWheelListeners() {
        return getListeners(MouseWheelListener.class);
    }

    
Adds the specified input method listener to receive input method events from this component. A component will only receive input method events from input methods if it also overrides getInputMethodRequests to return an InputMethodRequests instance. If listener l is null, no exception is thrown and no action is performed. 
Refer to
AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the input method listener
See Also:
Since:   1.2
/**
     * Adds the specified input method listener to receive
     * input method events from this component. A component will
     * only receive input method events from input methods
     * if it also overrides {@code getInputMethodRequests} to return an
     * {@code InputMethodRequests} instance.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to
     * <a href="{@docRoot}/java.desktop/java/awt/doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the input method listener
     * @see      java.awt.event.InputMethodEvent
     * @see      java.awt.event.InputMethodListener
     * @see      #removeInputMethodListener
     * @see      #getInputMethodListeners
     * @see      #getInputMethodRequests
     * @since    1.2
     */
    public synchronized void addInputMethodListener(InputMethodListener l) {
        if (l == null) {
            return;
        }
        inputMethodListener = AWTEventMulticaster.add(inputMethodListener, l);
        newEventsOnly = true;
    }

    
Removes the specified input method listener so that it no longer receives input method events from this component. This method performs no function, nor does it throw an exception, if the listener specified by the argument was not previously added to this component. If listener l is null, no exception is thrown and no action is performed. 
Refer to AWT Threading Issues for details on AWT's threading model.

Params:
  • l –   the input method listener
See Also:
Since:   1.2
/**
     * Removes the specified input method listener so that it no longer
     * receives input method events from this component. This method performs
     * no function, nor does it throw an exception, if the listener
     * specified by the argument was not previously added to this component.
     * If listener {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param    l   the input method listener
     * @see      java.awt.event.InputMethodEvent
     * @see      java.awt.event.InputMethodListener
     * @see      #addInputMethodListener
     * @see      #getInputMethodListeners
     * @since    1.2
     */
    public synchronized void removeInputMethodListener(InputMethodListener l) {
        if (l == null) {
            return;
        }
        inputMethodListener = AWTEventMulticaster.remove(inputMethodListener, l);
    }

    
Returns an array of all the input method listeners
registered on this component.

See Also:
Returns:all of this component's InputMethodListeners or an empty array if no input method listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the input method listeners
     * registered on this component.
     *
     * @return all of this component's {@code InputMethodListener}s
     *         or an empty array if no input method
     *         listeners are currently registered
     *
     * @see      #addInputMethodListener
     * @see      #removeInputMethodListener
     * @since    1.4
     */
    public synchronized InputMethodListener[] getInputMethodListeners() {
        return getListeners(InputMethodListener.class);
    }

    
Returns an array of all the objects currently registered
as FooListeners upon this Component. FooListeners are registered using the
addFooListener method.

 You can specify the listenerType argument with a class literal, such as FooListener.class. For example, you can query a Component c for its mouse listeners with the following code: 
MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class));

If no such listeners exist, this method returns an empty array.

Params:
  • listenerType – the type of listeners requested; this parameter should specify an interface that descends from java.util.EventListener
Type parameters:
  • <T> – the type of the listeners
Throws:
See Also:
Returns:an array of all objects registered as
         FooListeners on this component,
         or an empty array if no such listeners have been added
Since:1.3
/**
     * Returns an array of all the objects currently registered
     * as <code><em>Foo</em>Listener</code>s
     * upon this {@code Component}.
     * <code><em>Foo</em>Listener</code>s are registered using the
     * <code>add<em>Foo</em>Listener</code> method.
     *
     * <p>
     * You can specify the {@code listenerType} argument
     * with a class literal, such as
     * <code><em>Foo</em>Listener.class</code>.
     * For example, you can query a
     * {@code Component c}
     * for its mouse listeners with the following code:
     *
     * <pre>MouseListener[] mls = (MouseListener[])(c.getListeners(MouseListener.class));</pre>
     *
     * If no such listeners exist, this method returns an empty array.
     *
     * @param <T> the type of the listeners
     * @param listenerType the type of listeners requested; this parameter
     *          should specify an interface that descends from
     *          {@code java.util.EventListener}
     * @return an array of all objects registered as
     *          <code><em>Foo</em>Listener</code>s on this component,
     *          or an empty array if no such listeners have been added
     * @exception ClassCastException if {@code listenerType}
     *          doesn't specify a class or interface that implements
     *          {@code java.util.EventListener}
     * @throws NullPointerException if {@code listenerType} is {@code null}
     * @see #getComponentListeners
     * @see #getFocusListeners
     * @see #getHierarchyListeners
     * @see #getHierarchyBoundsListeners
     * @see #getKeyListeners
     * @see #getMouseListeners
     * @see #getMouseMotionListeners
     * @see #getMouseWheelListeners
     * @see #getInputMethodListeners
     * @see #getPropertyChangeListeners
     *
     * @since 1.3
     */
    @SuppressWarnings("unchecked")
    public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
        EventListener l = null;
        if  (listenerType == ComponentListener.class) {
            l = componentListener;
        } else if (listenerType == FocusListener.class) {
            l = focusListener;
        } else if (listenerType == HierarchyListener.class) {
            l = hierarchyListener;
        } else if (listenerType == HierarchyBoundsListener.class) {
            l = hierarchyBoundsListener;
        } else if (listenerType == KeyListener.class) {
            l = keyListener;
        } else if (listenerType == MouseListener.class) {
            l = mouseListener;
        } else if (listenerType == MouseMotionListener.class) {
            l = mouseMotionListener;
        } else if (listenerType == MouseWheelListener.class) {
            l = mouseWheelListener;
        } else if (listenerType == InputMethodListener.class) {
            l = inputMethodListener;
        } else if (listenerType == PropertyChangeListener.class) {
            return (T[])getPropertyChangeListeners();
        }
        return AWTEventMulticaster.getListeners(l, listenerType);
    }

    
Gets the input method request handler which supports requests from input methods for this component. A component that supports on-the-spot text input must override this method to return an InputMethodRequests instance. At the same time, it also has to handle input method events. 
See Also:
Returns:the input method request handler for this component, null by default
Since:1.2
/**
     * Gets the input method request handler which supports
     * requests from input methods for this component. A component
     * that supports on-the-spot text input must override this
     * method to return an {@code InputMethodRequests} instance.
     * At the same time, it also has to handle input method events.
     *
     * @return the input method request handler for this component,
     *          {@code null} by default
     * @see #addInputMethodListener
     * @since 1.2
     */
    public InputMethodRequests getInputMethodRequests() {
        return null;
    }

    
Gets the input context used by this component for handling
the communication with input methods when text is entered
in this component. By default, the input context used for
the parent component is returned. Components may
override this to return a private input context.

Returns:the input context used by this component; null if no context can be determined
Since:1.2
/**
     * Gets the input context used by this component for handling
     * the communication with input methods when text is entered
     * in this component. By default, the input context used for
     * the parent component is returned. Components may
     * override this to return a private input context.
     *
     * @return the input context used by this component;
     *          {@code null} if no context can be determined
     * @since 1.2
     */
    public InputContext getInputContext() {
        Container parent = this.parent;
        if (parent == null) {
            return null;
        } else {
            return parent.getInputContext();
        }
    }

    
Enables the events defined by the specified event mask parameter
to be delivered to this component.


Event types are automatically enabled when a listener for
that event type is added to the component.

 This method only needs to be invoked by subclasses of Component which desire to have the specified event types delivered to processEvent regardless of whether or not a listener is registered. 
Params:
  • eventsToEnable –   the event mask defining the event types
See Also:
Since:     1.1
/**
     * Enables the events defined by the specified event mask parameter
     * to be delivered to this component.
     * <p>
     * Event types are automatically enabled when a listener for
     * that event type is added to the component.
     * <p>
     * This method only needs to be invoked by subclasses of
     * {@code Component} which desire to have the specified event
     * types delivered to {@code processEvent} regardless of whether
     * or not a listener is registered.
     * @param      eventsToEnable   the event mask defining the event types
     * @see        #processEvent
     * @see        #disableEvents
     * @see        AWTEvent
     * @since      1.1
     */
    protected final void enableEvents(long eventsToEnable) {
        long notifyAncestors = 0;
        synchronized (this) {
            if ((eventsToEnable & AWTEvent.HIERARCHY_EVENT_MASK) != 0 &&
                hierarchyListener == null &&
                (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) == 0) {
                notifyAncestors |= AWTEvent.HIERARCHY_EVENT_MASK;
            }
            if ((eventsToEnable & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0 &&
                hierarchyBoundsListener == null &&
                (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) == 0) {
                notifyAncestors |= AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK;
            }
            eventMask |= eventsToEnable;
            newEventsOnly = true;
        }

        // if this is a lightweight component, enable mouse events
        // in the native container.
        if (peer instanceof LightweightPeer) {
            parent.proxyEnableEvents(eventMask);
        }
        if (notifyAncestors != 0) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(notifyAncestors, 1);
            }
        }
    }

    
Disables the events defined by the specified event mask parameter
from being delivered to this component.

Params:
  • eventsToDisable –   the event mask defining the event types
See Also:
Since:     1.1
/**
     * Disables the events defined by the specified event mask parameter
     * from being delivered to this component.
     * @param      eventsToDisable   the event mask defining the event types
     * @see        #enableEvents
     * @since      1.1
     */
    protected final void disableEvents(long eventsToDisable) {
        long notifyAncestors = 0;
        synchronized (this) {
            if ((eventsToDisable & AWTEvent.HIERARCHY_EVENT_MASK) != 0 &&
                hierarchyListener == null &&
                (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0) {
                notifyAncestors |= AWTEvent.HIERARCHY_EVENT_MASK;
            }
            if ((eventsToDisable & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK)!=0 &&
                hierarchyBoundsListener == null &&
                (eventMask & AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK) != 0) {
                notifyAncestors |= AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK;
            }
            eventMask &= ~eventsToDisable;
        }
        if (notifyAncestors != 0) {
            synchronized (getTreeLock()) {
                adjustListeningChildrenOnParent(notifyAncestors, -1);
            }
        }
    }

    transient sun.awt.EventQueueItem[] eventCache;

    
See Also:
/**
     * @see #isCoalescingEnabled
     * @see #checkCoalescing
     */
    private transient boolean coalescingEnabled = checkCoalescing();

    
Weak map of known coalesceEvent overriders.
Value indicates whether overriden.
Bootstrap classes are not included.

/**
     * Weak map of known coalesceEvent overriders.
     * Value indicates whether overriden.
     * Bootstrap classes are not included.
     */
    private static final Map<Class<?>, Boolean> coalesceMap =
        new java.util.WeakHashMap<Class<?>, Boolean>();

    
Indicates whether this class overrides coalesceEvents.
It is assumed that all classes that are loaded from the bootstrap
  do not.
The bootstrap class loader is assumed to be represented by null.
We do not check that the method really overrides
  (it might be static, private or package private).

/**
     * Indicates whether this class overrides coalesceEvents.
     * It is assumed that all classes that are loaded from the bootstrap
     *   do not.
     * The bootstrap class loader is assumed to be represented by null.
     * We do not check that the method really overrides
     *   (it might be static, private or package private).
     */
     private boolean checkCoalescing() {
         if (getClass().getClassLoader()==null) {
             return false;
         }
         final Class<? extends Component> clazz = getClass();
         synchronized (coalesceMap) {
             // Check cache.
             Boolean value = coalesceMap.get(clazz);
             if (value != null) {
                 return value;
             }

             // Need to check non-bootstraps.
             Boolean enabled = java.security.AccessController.doPrivileged(
                 new java.security.PrivilegedAction<Boolean>() {
                     public Boolean run() {
                         return isCoalesceEventsOverriden(clazz);
                     }
                 }
                 );
             coalesceMap.put(clazz, enabled);
             return enabled;
         }
     }

    
Parameter types of coalesceEvents(AWTEvent,AWTEVent).

/**
     * Parameter types of coalesceEvents(AWTEvent,AWTEVent).
     */
    private static final Class<?>[] coalesceEventsParams = {
        AWTEvent.class, AWTEvent.class
    };

    
Indicates whether a class or its superclasses override coalesceEvents.
Must be called with lock on coalesceMap and privileged.

See Also:
  • checkCoalescing
/**
     * Indicates whether a class or its superclasses override coalesceEvents.
     * Must be called with lock on coalesceMap and privileged.
     * @see #checkCoalescing
     */
    private static boolean isCoalesceEventsOverriden(Class<?> clazz) {
        assert Thread.holdsLock(coalesceMap);

        // First check superclass - we may not need to bother ourselves.
        Class<?> superclass = clazz.getSuperclass();
        if (superclass == null) {
            // Only occurs on implementations that
            //   do not use null to represent the bootstrap class loader.
            return false;
        }
        if (superclass.getClassLoader() != null) {
            Boolean value = coalesceMap.get(superclass);
            if (value == null) {
                // Not done already - recurse.
                if (isCoalesceEventsOverriden(superclass)) {
                    coalesceMap.put(superclass, true);
                    return true;
                }
            } else if (value) {
                return true;
            }
        }

        try {
            // Throws if not overriden.
            clazz.getDeclaredMethod(
                "coalesceEvents", coalesceEventsParams
                );
            return true;
        } catch (NoSuchMethodException e) {
            // Not present in this class.
            return false;
        }
    }

    
Indicates whether coalesceEvents may do something.

/**
     * Indicates whether coalesceEvents may do something.
     */
    final boolean isCoalescingEnabled() {
        return coalescingEnabled;
     }


    
Potentially coalesce an event being posted with an existing event. This method is called by EventQueue.postEvent if an event with the same ID as the event to be posted is found in the queue (both events must have this component as their source). This method either returns a coalesced event which replaces the existing event (and the new event is then discarded), or null to indicate that no combining should be done (add the second event to the end of the queue). Either event parameter may be modified and returned, as the other one is discarded unless null is returned. 
 This implementation of coalesceEvents coalesces two event types: mouse move (and drag) events, and paint (and update) events. For mouse move events the last event is always returned, causing intermediate moves to be discarded. For paint events, the new event is coalesced into a complex RepaintArea in the peer. The new AWTEvent is always returned. 
Params:
  • existingEvent –  the event already on the EventQueue
  • newEvent –  the event being posted to the EventQueue
Returns:a coalesced event, or null indicating that no coalescing was done
/**
     * Potentially coalesce an event being posted with an existing
     * event.  This method is called by {@code EventQueue.postEvent}
     * if an event with the same ID as the event to be posted is found in
     * the queue (both events must have this component as their source).
     * This method either returns a coalesced event which replaces
     * the existing event (and the new event is then discarded), or
     * {@code null} to indicate that no combining should be done
     * (add the second event to the end of the queue).  Either event
     * parameter may be modified and returned, as the other one is discarded
     * unless {@code null} is returned.
     * <p>
     * This implementation of {@code coalesceEvents} coalesces
     * two event types: mouse move (and drag) events,
     * and paint (and update) events.
     * For mouse move events the last event is always returned, causing
     * intermediate moves to be discarded.  For paint events, the new
     * event is coalesced into a complex {@code RepaintArea} in the peer.
     * The new {@code AWTEvent} is always returned.
     *
     * @param  existingEvent  the event already on the {@code EventQueue}
     * @param  newEvent       the event being posted to the
     *          {@code EventQueue}
     * @return a coalesced event, or {@code null} indicating that no
     *          coalescing was done
     */
    protected AWTEvent coalesceEvents(AWTEvent existingEvent,
                                      AWTEvent newEvent) {
        return null;
    }

    
Processes events occurring on this component. By default this
method calls the appropriate
process<event type>Event
method for the given class of event.

Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the event
See Also:
Since:    1.1
/**
     * Processes events occurring on this component. By default this
     * method calls the appropriate
     * <code>process&lt;event&nbsp;type&gt;Event</code>
     * method for the given class of event.
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param     e the event
     * @see       #processComponentEvent
     * @see       #processFocusEvent
     * @see       #processKeyEvent
     * @see       #processMouseEvent
     * @see       #processMouseMotionEvent
     * @see       #processInputMethodEvent
     * @see       #processHierarchyEvent
     * @see       #processMouseWheelEvent
     * @since     1.1
     */
    protected void processEvent(AWTEvent e) {
        if (e instanceof FocusEvent) {
            processFocusEvent((FocusEvent)e);

        } else if (e instanceof MouseEvent) {
            switch(e.getID()) {
              case MouseEvent.MOUSE_PRESSED:
              case MouseEvent.MOUSE_RELEASED:
              case MouseEvent.MOUSE_CLICKED:
              case MouseEvent.MOUSE_ENTERED:
              case MouseEvent.MOUSE_EXITED:
                  processMouseEvent((MouseEvent)e);
                  break;
              case MouseEvent.MOUSE_MOVED:
              case MouseEvent.MOUSE_DRAGGED:
                  processMouseMotionEvent((MouseEvent)e);
                  break;
              case MouseEvent.MOUSE_WHEEL:
                  processMouseWheelEvent((MouseWheelEvent)e);
                  break;
            }

        } else if (e instanceof KeyEvent) {
            processKeyEvent((KeyEvent)e);

        } else if (e instanceof ComponentEvent) {
            processComponentEvent((ComponentEvent)e);
        } else if (e instanceof InputMethodEvent) {
            processInputMethodEvent((InputMethodEvent)e);
        } else if (e instanceof HierarchyEvent) {
            switch (e.getID()) {
              case HierarchyEvent.HIERARCHY_CHANGED:
                  processHierarchyEvent((HierarchyEvent)e);
                  break;
              case HierarchyEvent.ANCESTOR_MOVED:
              case HierarchyEvent.ANCESTOR_RESIZED:
                  processHierarchyBoundsEvent((HierarchyEvent)e);
                  break;
            }
        }
    }

    
Processes component events occurring on this component by dispatching them to any registered ComponentListener objects. 

This method is not called unless component events are
enabled for this component. Component events are enabled
when one of the following occurs:

    

  • A ComponentListener object is registered via addComponentListener. 
  • Component events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the component event
See Also:
Since:      1.1
/**
     * Processes component events occurring on this component by
     * dispatching them to any registered
     * {@code ComponentListener} objects.
     * <p>
     * This method is not called unless component events are
     * enabled for this component. Component events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code ComponentListener} object is registered
     * via {@code addComponentListener}.
     * <li>Component events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the component event
     * @see         java.awt.event.ComponentEvent
     * @see         java.awt.event.ComponentListener
     * @see         #addComponentListener
     * @see         #enableEvents
     * @since       1.1
     */
    protected void processComponentEvent(ComponentEvent e) {
        ComponentListener listener = componentListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case ComponentEvent.COMPONENT_RESIZED:
                  listener.componentResized(e);
                  break;
              case ComponentEvent.COMPONENT_MOVED:
                  listener.componentMoved(e);
                  break;
              case ComponentEvent.COMPONENT_SHOWN:
                  listener.componentShown(e);
                  break;
              case ComponentEvent.COMPONENT_HIDDEN:
                  listener.componentHidden(e);
                  break;
            }
        }
    }

    
Processes focus events occurring on this component by dispatching them to any registered FocusListener objects. 

This method is not called unless focus events are
enabled for this component. Focus events are enabled
when one of the following occurs:

    

  • A FocusListener object is registered via addFocusListener. 
  • Focus events are enabled via enableEvents. 


 If focus events are enabled for a Component, the current KeyboardFocusManager determines whether or not a focus event should be dispatched to registered FocusListener objects. If the events are to be dispatched, the KeyboardFocusManager calls the Component's dispatchEvent method, which results in a call to the Component's processFocusEvent method. 
 If focus events are enabled for a Component, calling the Component's dispatchEvent method with a FocusEvent as the argument will result in a call to the Component's processFocusEvent method regardless of the current KeyboardFocusManager. 
Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the focus event
See Also:
Since:      1.1
/**
     * Processes focus events occurring on this component by
     * dispatching them to any registered
     * {@code FocusListener} objects.
     * <p>
     * This method is not called unless focus events are
     * enabled for this component. Focus events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code FocusListener} object is registered
     * via {@code addFocusListener}.
     * <li>Focus events are enabled via {@code enableEvents}.
     * </ul>
     * <p>
     * If focus events are enabled for a {@code Component},
     * the current {@code KeyboardFocusManager} determines
     * whether or not a focus event should be dispatched to
     * registered {@code FocusListener} objects.  If the
     * events are to be dispatched, the {@code KeyboardFocusManager}
     * calls the {@code Component}'s {@code dispatchEvent}
     * method, which results in a call to the {@code Component}'s
     * {@code processFocusEvent} method.
     * <p>
     * If focus events are enabled for a {@code Component}, calling
     * the {@code Component}'s {@code dispatchEvent} method
     * with a {@code FocusEvent} as the argument will result in a
     * call to the {@code Component}'s {@code processFocusEvent}
     * method regardless of the current {@code KeyboardFocusManager}.
     *
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the focus event
     * @see         java.awt.event.FocusEvent
     * @see         java.awt.event.FocusListener
     * @see         java.awt.KeyboardFocusManager
     * @see         #addFocusListener
     * @see         #enableEvents
     * @see         #dispatchEvent
     * @since       1.1
     */
    protected void processFocusEvent(FocusEvent e) {
        FocusListener listener = focusListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case FocusEvent.FOCUS_GAINED:
                  listener.focusGained(e);
                  break;
              case FocusEvent.FOCUS_LOST:
                  listener.focusLost(e);
                  break;
            }
        }
    }

    
Processes key events occurring on this component by dispatching them to any registered KeyListener objects. 

This method is not called unless key events are
enabled for this component. Key events are enabled
when one of the following occurs:

    

  • A KeyListener object is registered via addKeyListener. 
  • Key events are enabled via enableEvents. 


 If key events are enabled for a Component, the current KeyboardFocusManager determines whether or not a key event should be dispatched to registered KeyListener objects. The DefaultKeyboardFocusManager will not dispatch key events to a Component that is not the focus owner or is not showing. 
 As of J2SE 1.4, KeyEvents are redirected to the focus owner. Please see the Focus Specification
for further information.

 Calling a Component's dispatchEvent method with a KeyEvent as the argument will result in a call to the Component's processKeyEvent method regardless of the current KeyboardFocusManager as long as the component is showing, focused, and enabled, and key events are enabled on it. 
If the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the key event
See Also:
Since:      1.1
/**
     * Processes key events occurring on this component by
     * dispatching them to any registered
     * {@code KeyListener} objects.
     * <p>
     * This method is not called unless key events are
     * enabled for this component. Key events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code KeyListener} object is registered
     * via {@code addKeyListener}.
     * <li>Key events are enabled via {@code enableEvents}.
     * </ul>
     *
     * <p>
     * If key events are enabled for a {@code Component},
     * the current {@code KeyboardFocusManager} determines
     * whether or not a key event should be dispatched to
     * registered {@code KeyListener} objects.  The
     * {@code DefaultKeyboardFocusManager} will not dispatch
     * key events to a {@code Component} that is not the focus
     * owner or is not showing.
     * <p>
     * As of J2SE 1.4, {@code KeyEvent}s are redirected to
     * the focus owner. Please see the
     * <a href="doc-files/FocusSpec.html">Focus Specification</a>
     * for further information.
     * <p>
     * Calling a {@code Component}'s {@code dispatchEvent}
     * method with a {@code KeyEvent} as the argument will
     * result in a call to the {@code Component}'s
     * {@code processKeyEvent} method regardless of the
     * current {@code KeyboardFocusManager} as long as the
     * component is showing, focused, and enabled, and key events
     * are enabled on it.
     * <p>If the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the key event
     * @see         java.awt.event.KeyEvent
     * @see         java.awt.event.KeyListener
     * @see         java.awt.KeyboardFocusManager
     * @see         java.awt.DefaultKeyboardFocusManager
     * @see         #processEvent
     * @see         #dispatchEvent
     * @see         #addKeyListener
     * @see         #enableEvents
     * @see         #isShowing
     * @since       1.1
     */
    protected void processKeyEvent(KeyEvent e) {
        KeyListener listener = keyListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case KeyEvent.KEY_TYPED:
                  listener.keyTyped(e);
                  break;
              case KeyEvent.KEY_PRESSED:
                  listener.keyPressed(e);
                  break;
              case KeyEvent.KEY_RELEASED:
                  listener.keyReleased(e);
                  break;
            }
        }
    }

    
Processes mouse events occurring on this component by dispatching them to any registered MouseListener objects. 

This method is not called unless mouse events are
enabled for this component. Mouse events are enabled
when one of the following occurs:

    

  • A MouseListener object is registered via addMouseListener. 
  • Mouse events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the mouse event
See Also:
Since:      1.1
/**
     * Processes mouse events occurring on this component by
     * dispatching them to any registered
     * {@code MouseListener} objects.
     * <p>
     * This method is not called unless mouse events are
     * enabled for this component. Mouse events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code MouseListener} object is registered
     * via {@code addMouseListener}.
     * <li>Mouse events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the mouse event
     * @see         java.awt.event.MouseEvent
     * @see         java.awt.event.MouseListener
     * @see         #addMouseListener
     * @see         #enableEvents
     * @since       1.1
     */
    protected void processMouseEvent(MouseEvent e) {
        MouseListener listener = mouseListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case MouseEvent.MOUSE_PRESSED:
                  listener.mousePressed(e);
                  break;
              case MouseEvent.MOUSE_RELEASED:
                  listener.mouseReleased(e);
                  break;
              case MouseEvent.MOUSE_CLICKED:
                  listener.mouseClicked(e);
                  break;
              case MouseEvent.MOUSE_EXITED:
                  listener.mouseExited(e);
                  break;
              case MouseEvent.MOUSE_ENTERED:
                  listener.mouseEntered(e);
                  break;
            }
        }
    }

    
Processes mouse motion events occurring on this component by dispatching them to any registered MouseMotionListener objects. 

This method is not called unless mouse motion events are
enabled for this component. Mouse motion events are enabled
when one of the following occurs:

    

  • A MouseMotionListener object is registered via addMouseMotionListener. 
  • Mouse motion events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the mouse motion event
See Also:
Since:      1.1
/**
     * Processes mouse motion events occurring on this component by
     * dispatching them to any registered
     * {@code MouseMotionListener} objects.
     * <p>
     * This method is not called unless mouse motion events are
     * enabled for this component. Mouse motion events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code MouseMotionListener} object is registered
     * via {@code addMouseMotionListener}.
     * <li>Mouse motion events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the mouse motion event
     * @see         java.awt.event.MouseEvent
     * @see         java.awt.event.MouseMotionListener
     * @see         #addMouseMotionListener
     * @see         #enableEvents
     * @since       1.1
     */
    protected void processMouseMotionEvent(MouseEvent e) {
        MouseMotionListener listener = mouseMotionListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case MouseEvent.MOUSE_MOVED:
                  listener.mouseMoved(e);
                  break;
              case MouseEvent.MOUSE_DRAGGED:
                  listener.mouseDragged(e);
                  break;
            }
        }
    }

    
Processes mouse wheel events occurring on this component by dispatching them to any registered MouseWheelListener objects. 

This method is not called unless mouse wheel events are
enabled for this component. Mouse wheel events are enabled
when one of the following occurs:

    

  • A MouseWheelListener object is registered via addMouseWheelListener. 
  • Mouse wheel events are enabled via enableEvents. 


 For information on how mouse wheel events are dispatched, see the class description for MouseWheelEvent. 
 Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the mouse wheel event
See Also:
Since:      1.4
/**
     * Processes mouse wheel events occurring on this component by
     * dispatching them to any registered
     * {@code MouseWheelListener} objects.
     * <p>
     * This method is not called unless mouse wheel events are
     * enabled for this component. Mouse wheel events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>A {@code MouseWheelListener} object is registered
     * via {@code addMouseWheelListener}.
     * <li>Mouse wheel events are enabled via {@code enableEvents}.
     * </ul>
     * <p>
     * For information on how mouse wheel events are dispatched, see
     * the class description for {@link MouseWheelEvent}.
     * <p>
     * Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the mouse wheel event
     * @see         java.awt.event.MouseWheelEvent
     * @see         java.awt.event.MouseWheelListener
     * @see         #addMouseWheelListener
     * @see         #enableEvents
     * @since       1.4
     */
    protected void processMouseWheelEvent(MouseWheelEvent e) {
        MouseWheelListener listener = mouseWheelListener;
        if (listener != null) {
            int id = e.getID();
            switch(id) {
              case MouseEvent.MOUSE_WHEEL:
                  listener.mouseWheelMoved(e);
                  break;
            }
        }
    }

    boolean postsOldMouseEvents() {
        return false;
    }

    
Processes input method events occurring on this component by dispatching them to any registered InputMethodListener objects. 

This method is not called unless input method events
are enabled for this component. Input method events are enabled
when one of the following occurs:

    

  • An InputMethodListener object is registered via addInputMethodListener. 
  • Input method events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the input method event
See Also:
Since:      1.2
/**
     * Processes input method events occurring on this component by
     * dispatching them to any registered
     * {@code InputMethodListener} objects.
     * <p>
     * This method is not called unless input method events
     * are enabled for this component. Input method events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>An {@code InputMethodListener} object is registered
     * via {@code addInputMethodListener}.
     * <li>Input method events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the input method event
     * @see         java.awt.event.InputMethodEvent
     * @see         java.awt.event.InputMethodListener
     * @see         #addInputMethodListener
     * @see         #enableEvents
     * @since       1.2
     */
    protected void processInputMethodEvent(InputMethodEvent e) {
        InputMethodListener listener = inputMethodListener;
        if (listener != null) {
            int id = e.getID();
            switch (id) {
              case InputMethodEvent.INPUT_METHOD_TEXT_CHANGED:
                  listener.inputMethodTextChanged(e);
                  break;
              case InputMethodEvent.CARET_POSITION_CHANGED:
                  listener.caretPositionChanged(e);
                  break;
            }
        }
    }

    
Processes hierarchy events occurring on this component by dispatching them to any registered HierarchyListener objects. 

This method is not called unless hierarchy events
are enabled for this component. Hierarchy events are enabled
when one of the following occurs:

    

  • An HierarchyListener object is registered via addHierarchyListener. 
  • Hierarchy events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the hierarchy event
See Also:
Since:      1.3
/**
     * Processes hierarchy events occurring on this component by
     * dispatching them to any registered
     * {@code HierarchyListener} objects.
     * <p>
     * This method is not called unless hierarchy events
     * are enabled for this component. Hierarchy events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>An {@code HierarchyListener} object is registered
     * via {@code addHierarchyListener}.
     * <li>Hierarchy events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the hierarchy event
     * @see         java.awt.event.HierarchyEvent
     * @see         java.awt.event.HierarchyListener
     * @see         #addHierarchyListener
     * @see         #enableEvents
     * @since       1.3
     */
    protected void processHierarchyEvent(HierarchyEvent e) {
        HierarchyListener listener = hierarchyListener;
        if (listener != null) {
            int id = e.getID();
            switch (id) {
              case HierarchyEvent.HIERARCHY_CHANGED:
                  listener.hierarchyChanged(e);
                  break;
            }
        }
    }

    
Processes hierarchy bounds events occurring on this component by dispatching them to any registered HierarchyBoundsListener objects. 

This method is not called unless hierarchy bounds events
are enabled for this component. Hierarchy bounds events are enabled
when one of the following occurs:

    

  • An HierarchyBoundsListener object is registered via addHierarchyBoundsListener. 
  • Hierarchy bounds events are enabled via enableEvents. 


Note that if the event parameter is null the behavior is unspecified and may result in an exception. 
Params:
  • e – the hierarchy event
See Also:
Since:      1.3
/**
     * Processes hierarchy bounds events occurring on this component by
     * dispatching them to any registered
     * {@code HierarchyBoundsListener} objects.
     * <p>
     * This method is not called unless hierarchy bounds events
     * are enabled for this component. Hierarchy bounds events are enabled
     * when one of the following occurs:
     * <ul>
     * <li>An {@code HierarchyBoundsListener} object is registered
     * via {@code addHierarchyBoundsListener}.
     * <li>Hierarchy bounds events are enabled via {@code enableEvents}.
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param       e the hierarchy event
     * @see         java.awt.event.HierarchyEvent
     * @see         java.awt.event.HierarchyBoundsListener
     * @see         #addHierarchyBoundsListener
     * @see         #enableEvents
     * @since       1.3
     */
    protected void processHierarchyBoundsEvent(HierarchyEvent e) {
        HierarchyBoundsListener listener = hierarchyBoundsListener;
        if (listener != null) {
            int id = e.getID();
            switch (id) {
              case HierarchyEvent.ANCESTOR_MOVED:
                  listener.ancestorMoved(e);
                  break;
              case HierarchyEvent.ANCESTOR_RESIZED:
                  listener.ancestorResized(e);
                  break;
            }
        }
    }

    
Params:
  • evt – the event to handle
Returns:true if the event was handled, false otherwise
Deprecated:As of JDK version 1.1
replaced by processEvent(AWTEvent).
/**
     * @param  evt the event to handle
     * @return {@code true} if the event was handled, {@code false} otherwise
     * @deprecated As of JDK version 1.1
     * replaced by processEvent(AWTEvent).
     */
    @Deprecated
    public boolean handleEvent(Event evt) {
        switch (evt.id) {
          case Event.MOUSE_ENTER:
              return mouseEnter(evt, evt.x, evt.y);

          case Event.MOUSE_EXIT:
              return mouseExit(evt, evt.x, evt.y);

          case Event.MOUSE_MOVE:
              return mouseMove(evt, evt.x, evt.y);

          case Event.MOUSE_DOWN:
              return mouseDown(evt, evt.x, evt.y);

          case Event.MOUSE_DRAG:
              return mouseDrag(evt, evt.x, evt.y);

          case Event.MOUSE_UP:
              return mouseUp(evt, evt.x, evt.y);

          case Event.KEY_PRESS:
          case Event.KEY_ACTION:
              return keyDown(evt, evt.key);

          case Event.KEY_RELEASE:
          case Event.KEY_ACTION_RELEASE:
              return keyUp(evt, evt.key);

          case Event.ACTION_EVENT:
              return action(evt, evt.arg);
          case Event.GOT_FOCUS:
              return gotFocus(evt, evt.arg);
          case Event.LOST_FOCUS:
              return lostFocus(evt, evt.arg);
        }
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseDown(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseMotionEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseMotionEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseDrag(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseUp(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseMotionEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseMotionEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseMove(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseEnter(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • x – the x coordinate
  • y – the y coordinate
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processMouseEvent(MouseEvent).
/**
     * @param  evt the event to handle
     * @param  x the x coordinate
     * @param  y the y coordinate
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processMouseEvent(MouseEvent).
     */
    @Deprecated
    public boolean mouseExit(Event evt, int x, int y) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • key – the key pressed
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processKeyEvent(KeyEvent).
/**
     * @param  evt the event to handle
     * @param  key the key pressed
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processKeyEvent(KeyEvent).
     */
    @Deprecated
    public boolean keyDown(Event evt, int key) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • key – the key pressed
Returns:false
Deprecated:As of JDK version 1.1,
replaced by processKeyEvent(KeyEvent).
/**
     * @param  evt the event to handle
     * @param  key the key pressed
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processKeyEvent(KeyEvent).
     */
    @Deprecated
    public boolean keyUp(Event evt, int key) {
        return false;
    }

    
Params:
  • evt – the event to handle
  • what – the object acted on
Returns:false
Deprecated:As of JDK version 1.1,
should register this component as ActionListener on component
which fires action events.
/**
     * @param  evt the event to handle
     * @param  what the object acted on
     * @return {@code false}
     * @deprecated As of JDK version 1.1,
     * should register this component as ActionListener on component
     * which fires action events.
     */
    @Deprecated
    public boolean action(Event evt, Object what) {
        return false;
    }

    
Makes this Component displayable by connecting it to a native screen resource. This method is called internally by the toolkit and should not be called directly by programs. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

See Also:
Since:1.0
/**
     * Makes this {@code Component} displayable by connecting it to a
     * native screen resource.
     * This method is called internally by the toolkit and should
     * not be called directly by programs.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @see       #isDisplayable
     * @see       #removeNotify
     * @see #invalidate
     * @since 1.0
     */
    public void addNotify() {
        synchronized (getTreeLock()) {
            ComponentPeer peer = this.peer;
            if (peer == null || peer instanceof LightweightPeer){
                if (peer == null) {
                    // Update both the Component's peer variable and the local
                    // variable we use for thread safety.
                    this.peer = peer = getComponentFactory().createComponent(this);
                }

                // This is a lightweight component which means it won't be
                // able to get window-related events by itself.  If any
                // have been enabled, then the nearest native container must
                // be enabled.
                if (parent != null) {
                    long mask = 0;
                    if ((mouseListener != null) || ((eventMask & AWTEvent.MOUSE_EVENT_MASK) != 0)) {
                        mask |= AWTEvent.MOUSE_EVENT_MASK;
                    }
                    if ((mouseMotionListener != null) ||
                        ((eventMask & AWTEvent.MOUSE_MOTION_EVENT_MASK) != 0)) {
                        mask |= AWTEvent.MOUSE_MOTION_EVENT_MASK;
                    }
                    if ((mouseWheelListener != null ) ||
                        ((eventMask & AWTEvent.MOUSE_WHEEL_EVENT_MASK) != 0)) {
                        mask |= AWTEvent.MOUSE_WHEEL_EVENT_MASK;
                    }
                    if (focusListener != null || (eventMask & AWTEvent.FOCUS_EVENT_MASK) != 0) {
                        mask |= AWTEvent.FOCUS_EVENT_MASK;
                    }
                    if (keyListener != null || (eventMask & AWTEvent.KEY_EVENT_MASK) != 0) {
                        mask |= AWTEvent.KEY_EVENT_MASK;
                    }
                    if (mask != 0) {
                        parent.proxyEnableEvents(mask);
                    }
                }
            } else {
                // It's native. If the parent is lightweight it will need some
                // help.
                Container parent = getContainer();
                if (parent != null && parent.isLightweight()) {
                    relocateComponent();
                    if (!parent.isRecursivelyVisibleUpToHeavyweightContainer())
                    {
                        peer.setVisible(false);
                    }
                }
            }
            invalidate();

            int npopups = (popups != null? popups.size() : 0);
            for (int i = 0 ; i < npopups ; i++) {
                PopupMenu popup = popups.elementAt(i);
                popup.addNotify();
            }

            if (dropTarget != null) dropTarget.addNotify();

            peerFont = getFont();

            if (getContainer() != null && !isAddNotifyComplete) {
                getContainer().increaseComponentCount(this);
            }


            // Update stacking order
            updateZOrder();

            if (!isAddNotifyComplete) {
                mixOnShowing();
            }

            isAddNotifyComplete = true;

            if (hierarchyListener != null ||
                (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0 ||
                Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK)) {
                HierarchyEvent e =
                    new HierarchyEvent(this, HierarchyEvent.HIERARCHY_CHANGED,
                                       this, parent,
                                       HierarchyEvent.DISPLAYABILITY_CHANGED |
                                       ((isRecursivelyVisible())
                                        ? HierarchyEvent.SHOWING_CHANGED
                                        : 0));
                dispatchEvent(e);
            }
        }
    }

    
Makes this Component undisplayable by destroying it native screen resource. 
 This method is called by the toolkit internally and should not be called directly by programs. Code overriding this method should call super.removeNotify as the first line of the overriding method. 
See Also:
Since:1.0
/**
     * Makes this {@code Component} undisplayable by destroying it native
     * screen resource.
     * <p>
     * This method is called by the toolkit internally and should
     * not be called directly by programs. Code overriding
     * this method should call {@code super.removeNotify} as
     * the first line of the overriding method.
     *
     * @see       #isDisplayable
     * @see       #addNotify
     * @since 1.0
     */
    public void removeNotify() {
        KeyboardFocusManager.clearMostRecentFocusOwner(this);
        if (KeyboardFocusManager.getCurrentKeyboardFocusManager().
            getPermanentFocusOwner() == this)
        {
            KeyboardFocusManager.getCurrentKeyboardFocusManager().
                setGlobalPermanentFocusOwner(null);
        }

        synchronized (getTreeLock()) {
            if (isFocusOwner() && KeyboardFocusManager.isAutoFocusTransferEnabledFor(this)) {
                transferFocus(true);
            }

            if (getContainer() != null && isAddNotifyComplete) {
                getContainer().decreaseComponentCount(this);
            }

            int npopups = (popups != null? popups.size() : 0);
            for (int i = 0 ; i < npopups ; i++) {
                PopupMenu popup = popups.elementAt(i);
                popup.removeNotify();
            }
            // If there is any input context for this component, notify
            // that this component is being removed. (This has to be done
            // before hiding peer.)
            if ((eventMask & AWTEvent.INPUT_METHODS_ENABLED_MASK) != 0) {
                InputContext inputContext = getInputContext();
                if (inputContext != null) {
                    inputContext.removeNotify(this);
                }
            }

            ComponentPeer p = peer;
            if (p != null) {
                boolean isLightweight = isLightweight();

                if (bufferStrategy instanceof FlipBufferStrategy) {
                    ((FlipBufferStrategy)bufferStrategy).invalidate();
                }

                if (dropTarget != null) dropTarget.removeNotify();

                // Hide peer first to stop system events such as cursor moves.
                if (visible) {
                    p.setVisible(false);
                }

                peer = null; // Stop peer updates.
                peerFont = null;

                Toolkit.getEventQueue().removeSourceEvents(this, false);
                KeyboardFocusManager.getCurrentKeyboardFocusManager().
                    discardKeyEvents(this);

                p.dispose();

                mixOnHiding(isLightweight);

                isAddNotifyComplete = false;
                // Nullifying compoundShape means that the component has normal shape
                // (or has no shape at all).
                this.compoundShape = null;
            }

            if (hierarchyListener != null ||
                (eventMask & AWTEvent.HIERARCHY_EVENT_MASK) != 0 ||
                Toolkit.enabledOnToolkit(AWTEvent.HIERARCHY_EVENT_MASK)) {
                HierarchyEvent e =
                    new HierarchyEvent(this, HierarchyEvent.HIERARCHY_CHANGED,
                                       this, parent,
                                       HierarchyEvent.DISPLAYABILITY_CHANGED |
                                       ((isRecursivelyVisible())
                                        ? HierarchyEvent.SHOWING_CHANGED
                                        : 0));
                dispatchEvent(e);
            }
        }
    }

    
Params:
  • evt – the event to handle
  • what – the object focused
Returns: false
Deprecated:As of JDK version 1.1,
replaced by processFocusEvent(FocusEvent).
/**
     * @param  evt the event to handle
     * @param  what the object focused
     * @return  {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processFocusEvent(FocusEvent).
     */
    @Deprecated
    public boolean gotFocus(Event evt, Object what) {
        return false;
    }

    
Params:
  • evt –  the event to handle
  • what – the object focused
Returns: false
Deprecated:As of JDK version 1.1,
replaced by processFocusEvent(FocusEvent).
/**
     * @param evt  the event to handle
     * @param what the object focused
     * @return  {@code false}
     * @deprecated As of JDK version 1.1,
     * replaced by processFocusEvent(FocusEvent).
     */
    @Deprecated
    public boolean lostFocus(Event evt, Object what) {
        return false;
    }

    
Returns whether this Component can become the focus owner. 
See Also:
Returns:true if this Component is focusable; false otherwise
Since:1.1
Deprecated:As of 1.4, replaced by isFocusable().
/**
     * Returns whether this {@code Component} can become the focus
     * owner.
     *
     * @return {@code true} if this {@code Component} is
     * focusable; {@code false} otherwise
     * @see #setFocusable
     * @since 1.1
     * @deprecated As of 1.4, replaced by {@code isFocusable()}.
     */
    @Deprecated
    public boolean isFocusTraversable() {
        if (isFocusTraversableOverridden == FOCUS_TRAVERSABLE_UNKNOWN) {
            isFocusTraversableOverridden = FOCUS_TRAVERSABLE_DEFAULT;
        }
        return focusable;
    }

    
Returns whether this Component can be focused.

See Also:
Returns:true if this Component is focusable; false otherwise.
Since:1.4
/**
     * Returns whether this Component can be focused.
     *
     * @return {@code true} if this Component is focusable;
     *         {@code false} otherwise.
     * @see #setFocusable
     * @since 1.4
     */
    public boolean isFocusable() {
        return isFocusTraversable();
    }

    
Sets the focusable state of this Component to the specified value. This
value overrides the Component's default focusability.

Params:
  • focusable – indicates whether this Component is focusable
See Also:
Since:1.4
/**
     * Sets the focusable state of this Component to the specified value. This
     * value overrides the Component's default focusability.
     *
     * @param focusable indicates whether this Component is focusable
     * @see #isFocusable
     * @since 1.4
     */
    public void setFocusable(boolean focusable) {
        boolean oldFocusable;
        synchronized (this) {
            oldFocusable = this.focusable;
            this.focusable = focusable;
        }
        isFocusTraversableOverridden = FOCUS_TRAVERSABLE_SET;

        firePropertyChange("focusable", oldFocusable, focusable);
        if (oldFocusable && !focusable) {
            if (isFocusOwner() && KeyboardFocusManager.isAutoFocusTransferEnabled()) {
                transferFocus(true);
            }
            KeyboardFocusManager.clearMostRecentFocusOwner(this);
        }
    }

    final boolean isFocusTraversableOverridden() {
        return (isFocusTraversableOverridden != FOCUS_TRAVERSABLE_DEFAULT);
    }

    
Sets the focus traversal keys for a given traversal operation for this
Component.


The default values for a Component's focus traversal keys are
implementation-dependent. Sun recommends that all implementations for a
particular native platform use the same default values. The
recommendations for Windows and Unix are listed below. These
recommendations are used in the Sun AWT implementations.


Recommended default values for a Component's focus traversal
keys

  

    Identifier
    Meaning
    Default



  

    KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS
    Normal forward keyboard traversal
    TAB on KEY_PRESSED, CTRL-TAB on KEY_PRESSED
  

    KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS
    Normal reverse keyboard traversal
    SHIFT-TAB on KEY_PRESSED, CTRL-SHIFT-TAB on KEY_PRESSED
  

    KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
    Go up one focus traversal cycle
    none




To disable a traversal key, use an empty Set; Collections.EMPTY_SET is
recommended.


Using the AWTKeyStroke API, client code can specify on which of two
specific KeyEvents, KEY_PRESSED or KEY_RELEASED, the focus traversal
operation will occur. Regardless of which KeyEvent is specified,
however, all KeyEvents related to the focus traversal key, including the
associated KEY_TYPED event, will be consumed, and will not be dispatched
to any Component. It is a runtime error to specify a KEY_TYPED event as
mapping to a focus traversal operation, or to map the same event to
multiple default focus traversal operations.


If a value of null is specified for the Set, this Component inherits the
Set from its parent. If all ancestors of this Component have null
specified for the Set, then the current KeyboardFocusManager's default
Set is used.

 This method may throw a ClassCastException if any Object in keystrokes is not an AWTKeyStroke. 
Params:
  • id – one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
       KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
       KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
  • keystrokes – the Set of AWTKeyStroke for the specified operation
Throws:
  • IllegalArgumentException – if id is not one of
        KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or if keystrokes
        contains null, or if any keystroke represents a KEY_TYPED event,
        or if any keystroke already maps to another focus traversal
        operation for this Component
See Also:
Since:1.4
/**
     * Sets the focus traversal keys for a given traversal operation for this
     * Component.
     * <p>
     * The default values for a Component's focus traversal keys are
     * implementation-dependent. Sun recommends that all implementations for a
     * particular native platform use the same default values. The
     * recommendations for Windows and Unix are listed below. These
     * recommendations are used in the Sun AWT implementations.
     *
     * <table class="striped">
     * <caption>Recommended default values for a Component's focus traversal
     * keys</caption>
     * <thead>
     *   <tr>
     *     <th scope="col">Identifier
     *     <th scope="col">Meaning
     *     <th scope="col">Default
     * </thead>
     * <tbody>
     *   <tr>
     *     <th scope="row">KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS
     *     <td>Normal forward keyboard traversal
     *     <td>TAB on KEY_PRESSED, CTRL-TAB on KEY_PRESSED
     *   <tr>
     *     <th scope="row">KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS
     *     <td>Normal reverse keyboard traversal
     *     <td>SHIFT-TAB on KEY_PRESSED, CTRL-SHIFT-TAB on KEY_PRESSED
     *   <tr>
     *     <th scope="row">KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     *     <td>Go up one focus traversal cycle
     *     <td>none
     * </tbody>
     * </table>
     *
     * To disable a traversal key, use an empty Set; Collections.EMPTY_SET is
     * recommended.
     * <p>
     * Using the AWTKeyStroke API, client code can specify on which of two
     * specific KeyEvents, KEY_PRESSED or KEY_RELEASED, the focus traversal
     * operation will occur. Regardless of which KeyEvent is specified,
     * however, all KeyEvents related to the focus traversal key, including the
     * associated KEY_TYPED event, will be consumed, and will not be dispatched
     * to any Component. It is a runtime error to specify a KEY_TYPED event as
     * mapping to a focus traversal operation, or to map the same event to
     * multiple default focus traversal operations.
     * <p>
     * If a value of null is specified for the Set, this Component inherits the
     * Set from its parent. If all ancestors of this Component have null
     * specified for the Set, then the current KeyboardFocusManager's default
     * Set is used.
     * <p>
     * This method may throw a {@code ClassCastException} if any {@code Object}
     * in {@code keystrokes} is not an {@code AWTKeyStroke}.
     *
     * @param id one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     * @param keystrokes the Set of AWTKeyStroke for the specified operation
     * @see #getFocusTraversalKeys
     * @see KeyboardFocusManager#FORWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#BACKWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#UP_CYCLE_TRAVERSAL_KEYS
     * @throws IllegalArgumentException if id is not one of
     *         KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *         KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or if keystrokes
     *         contains null, or if any keystroke represents a KEY_TYPED event,
     *         or if any keystroke already maps to another focus traversal
     *         operation for this Component
     * @since 1.4
     */
    public void setFocusTraversalKeys(int id,
                                      Set<? extends AWTKeyStroke> keystrokes)
    {
        if (id < 0 || id >= KeyboardFocusManager.TRAVERSAL_KEY_LENGTH - 1) {
            throw new IllegalArgumentException("invalid focus traversal key identifier");
        }

        setFocusTraversalKeys_NoIDCheck(id, keystrokes);
    }

    
Returns the Set of focus traversal keys for a given traversal operation for this Component. (See setFocusTraversalKeys for a full description of each key.) 

If a Set of traversal keys has not been explicitly defined for this
Component, then this Component's parent's Set is returned. If no Set
has been explicitly defined for any of this Component's ancestors, then
the current KeyboardFocusManager's default Set is returned.

Params:
  • id – one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
       KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
       KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
Throws:
  • IllegalArgumentException – if id is not one of
        KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
See Also:
Returns:the Set of AWTKeyStrokes for the specified operation. The Set
        will be unmodifiable, and may be empty. null will never be
        returned.
Since:1.4
/**
     * Returns the Set of focus traversal keys for a given traversal operation
     * for this Component. (See
     * {@code setFocusTraversalKeys} for a full description of each key.)
     * <p>
     * If a Set of traversal keys has not been explicitly defined for this
     * Component, then this Component's parent's Set is returned. If no Set
     * has been explicitly defined for any of this Component's ancestors, then
     * the current KeyboardFocusManager's default Set is returned.
     *
     * @param id one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     * @return the Set of AWTKeyStrokes for the specified operation. The Set
     *         will be unmodifiable, and may be empty. null will never be
     *         returned.
     * @see #setFocusTraversalKeys
     * @see KeyboardFocusManager#FORWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#BACKWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#UP_CYCLE_TRAVERSAL_KEYS
     * @throws IllegalArgumentException if id is not one of
     *         KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *         KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     * @since 1.4
     */
    public Set<AWTKeyStroke> getFocusTraversalKeys(int id) {
        if (id < 0 || id >= KeyboardFocusManager.TRAVERSAL_KEY_LENGTH - 1) {
            throw new IllegalArgumentException("invalid focus traversal key identifier");
        }

        return getFocusTraversalKeys_NoIDCheck(id);
    }

    // We define these methods so that Container does not need to repeat this
    // code. Container cannot call super.<method> because Container allows
    // DOWN_CYCLE_TRAVERSAL_KEY while Component does not. The Component method
    // would erroneously generate an IllegalArgumentException for
    // DOWN_CYCLE_TRAVERSAL_KEY.
    final void setFocusTraversalKeys_NoIDCheck(int id, Set<? extends AWTKeyStroke> keystrokes) {
        Set<AWTKeyStroke> oldKeys;

        synchronized (this) {
            if (focusTraversalKeys == null) {
                initializeFocusTraversalKeys();
            }

            if (keystrokes != null) {
                for (AWTKeyStroke keystroke : keystrokes ) {

                    if (keystroke == null) {
                        throw new IllegalArgumentException("cannot set null focus traversal key");
                    }

                    if (keystroke.getKeyChar() != KeyEvent.CHAR_UNDEFINED) {
                        throw new IllegalArgumentException("focus traversal keys cannot map to KEY_TYPED events");
                    }

                    for (int i = 0; i < focusTraversalKeys.length; i++) {
                        if (i == id) {
                            continue;
                        }

                        if (getFocusTraversalKeys_NoIDCheck(i).contains(keystroke))
                        {
                            throw new IllegalArgumentException("focus traversal keys must be unique for a Component");
                        }
                    }
                }
            }

            oldKeys = focusTraversalKeys[id];
            focusTraversalKeys[id] = (keystrokes != null)
                ? Collections.unmodifiableSet(new HashSet<AWTKeyStroke>(keystrokes))
                : null;
        }

        firePropertyChange(focusTraversalKeyPropertyNames[id], oldKeys,
                           keystrokes);
    }
    final Set<AWTKeyStroke> getFocusTraversalKeys_NoIDCheck(int id) {
        // Okay to return Set directly because it is an unmodifiable view
        @SuppressWarnings("unchecked")
        Set<AWTKeyStroke> keystrokes = (focusTraversalKeys != null)
            ? focusTraversalKeys[id]
            : null;

        if (keystrokes != null) {
            return keystrokes;
        } else {
            Container parent = this.parent;
            if (parent != null) {
                return parent.getFocusTraversalKeys(id);
            } else {
                return KeyboardFocusManager.getCurrentKeyboardFocusManager().
                    getDefaultFocusTraversalKeys(id);
            }
        }
    }

    
Returns whether the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Component. If this method returns false, this Component is inheriting the Set from an ancestor, or from the current KeyboardFocusManager. 
Params:
  • id – one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
       KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
       KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
Throws:
  • IllegalArgumentException – if id is not one of
        KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
Returns:true if the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Component; false otherwise.
Since:1.4
/**
     * Returns whether the Set of focus traversal keys for the given focus
     * traversal operation has been explicitly defined for this Component. If
     * this method returns {@code false}, this Component is inheriting the
     * Set from an ancestor, or from the current KeyboardFocusManager.
     *
     * @param id one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *        KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *        KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     * @return {@code true} if the Set of focus traversal keys for the
     *         given focus traversal operation has been explicitly defined for
     *         this Component; {@code false} otherwise.
     * @throws IllegalArgumentException if id is not one of
     *         KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, or
     *         KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS
     * @since 1.4
     */
    public boolean areFocusTraversalKeysSet(int id) {
        if (id < 0 || id >= KeyboardFocusManager.TRAVERSAL_KEY_LENGTH - 1) {
            throw new IllegalArgumentException("invalid focus traversal key identifier");
        }

        return (focusTraversalKeys != null && focusTraversalKeys[id] != null);
    }

    
Sets whether focus traversal keys are enabled for this Component.
Components for which focus traversal keys are disabled receive key
events for focus traversal keys. Components for which focus traversal
keys are enabled do not see these events; instead, the events are
automatically converted to traversal operations.

Params:
  • focusTraversalKeysEnabled – whether focus traversal keys are
       enabled for this Component
See Also:
Since:1.4
/**
     * Sets whether focus traversal keys are enabled for this Component.
     * Components for which focus traversal keys are disabled receive key
     * events for focus traversal keys. Components for which focus traversal
     * keys are enabled do not see these events; instead, the events are
     * automatically converted to traversal operations.
     *
     * @param focusTraversalKeysEnabled whether focus traversal keys are
     *        enabled for this Component
     * @see #getFocusTraversalKeysEnabled
     * @see #setFocusTraversalKeys
     * @see #getFocusTraversalKeys
     * @since 1.4
     */
    public void setFocusTraversalKeysEnabled(boolean
                                             focusTraversalKeysEnabled) {
        boolean oldFocusTraversalKeysEnabled;
        synchronized (this) {
            oldFocusTraversalKeysEnabled = this.focusTraversalKeysEnabled;
            this.focusTraversalKeysEnabled = focusTraversalKeysEnabled;
        }
        firePropertyChange("focusTraversalKeysEnabled",
                           oldFocusTraversalKeysEnabled,
                           focusTraversalKeysEnabled);
    }

    
Returns whether focus traversal keys are enabled for this Component.
Components for which focus traversal keys are disabled receive key
events for focus traversal keys. Components for which focus traversal
keys are enabled do not see these events; instead, the events are
automatically converted to traversal operations.

See Also:
Returns:whether focus traversal keys are enabled for this Component
Since:1.4
/**
     * Returns whether focus traversal keys are enabled for this Component.
     * Components for which focus traversal keys are disabled receive key
     * events for focus traversal keys. Components for which focus traversal
     * keys are enabled do not see these events; instead, the events are
     * automatically converted to traversal operations.
     *
     * @return whether focus traversal keys are enabled for this Component
     * @see #setFocusTraversalKeysEnabled
     * @see #setFocusTraversalKeys
     * @see #getFocusTraversalKeys
     * @since 1.4
     */
    public boolean getFocusTraversalKeysEnabled() {
        return focusTraversalKeysEnabled;
    }

    
Requests that this Component get the input focus, and that this
Component's top-level ancestor become the focused Window. This
component must be displayable, focusable, visible and all of
its ancestors (with the exception of the top-level Window) must
be visible for the request to be granted. Every effort will be
made to honor the request; however, in some cases it may be
impossible to do so. Developers must never assume that this
Component is the focus owner until this Component receives a
FOCUS_GAINED event. If this request is denied because this
Component's top-level Window cannot become the focused Window,
the request will be remembered and will be granted when the
Window is later focused by the user.

 This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead. 
 Because the focus behavior of this method is platform-dependent, developers are strongly encouraged to use requestFocusInWindow when possible. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
See Also:
Since:1.0
/**
     * Requests that this Component get the input focus, and that this
     * Component's top-level ancestor become the focused Window. This
     * component must be displayable, focusable, visible and all of
     * its ancestors (with the exception of the top-level Window) must
     * be visible for the request to be granted. Every effort will be
     * made to honor the request; however, in some cases it may be
     * impossible to do so. Developers must never assume that this
     * Component is the focus owner until this Component receives a
     * FOCUS_GAINED event. If this request is denied because this
     * Component's top-level Window cannot become the focused Window,
     * the request will be remembered and will be granted when the
     * Window is later focused by the user.
     * <p>
     * This method cannot be used to set the focus owner to no Component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner()}
     * instead.
     * <p>
     * Because the focus behavior of this method is platform-dependent,
     * developers are strongly encouraged to use
     * {@code requestFocusInWindow} when possible.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @see #requestFocusInWindow
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 1.0
     */
    public void requestFocus() {
        requestFocusHelper(false, true);
    }


    
Requests by the reason of cause that this Component get the input focus, and that this Component's top-level ancestor become the focused Window. This component must be displayable, focusable, visible and all of its ancestors (with the exception of the top-level Window) must be visible for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event. 
 The focus request effect may also depend on the provided cause value. If this request is succeed the FocusEvent generated in the result will receive the cause value specified as the argument of method. If this request is denied because this Component's top-level Window cannot become the focused Window, the request will be remembered and will be granted when the Window is later focused by the user. 
 This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead. 
 Because the focus behavior of this method is platform-dependent, developers are strongly encouraged to use requestFocusInWindow(FocusEvent.Cause) when possible. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
Params:
  • cause – the cause why the focus is requested
See Also:
Since:9
/**
     * Requests by the reason of {@code cause} that this Component get the input
     * focus, and that this Component's top-level ancestor become the
     * focused Window. This component must be displayable, focusable, visible
     * and all of its ancestors (with the exception of the top-level Window)
     * must be visible for the request to be granted. Every effort will be
     * made to honor the request; however, in some cases it may be
     * impossible to do so. Developers must never assume that this
     * Component is the focus owner until this Component receives a
     * FOCUS_GAINED event.
     * <p>
     * The focus request effect may also depend on the provided
     * cause value. If this request is succeed the {@code FocusEvent}
     * generated in the result will receive the cause value specified as the
     * argument of method. If this request is denied because this Component's
     * top-level Window cannot become the focused Window, the request will be
     * remembered and will be granted when the Window is later focused by the
     * user.
     * <p>
     * This method cannot be used to set the focus owner to no Component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner()}
     * instead.
     * <p>
     * Because the focus behavior of this method is platform-dependent,
     * developers are strongly encouraged to use
     * {@code requestFocusInWindow(FocusEvent.Cause)} when possible.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @param  cause the cause why the focus is requested
     * @see FocusEvent
     * @see FocusEvent.Cause
     * @see #requestFocusInWindow(FocusEvent.Cause)
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 9
     */
    public void requestFocus(FocusEvent.Cause cause) {
        requestFocusHelper(false, true, cause);
    }

    
Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window. This component must be displayable, focusable, visible and all of its ancestors (with the exception of the top-level Window) must be visible for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. If this request is denied because this component's top-level window cannot become the focused window, the request will be remembered and will be granted when the window is later focused by the user. 
 This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. 
 This method cannot be used to set the focus owner to no component at all. Use KeyboardFocusManager.clearGlobalFocusOwner instead. 
 Because the focus behavior of this method is platform-dependent, developers are strongly encouraged to use requestFocusInWindow when possible. 
 Every effort will be made to ensure that FocusEvents generated as a result of this request will have the specified temporary value. However, because specifying an arbitrary temporary state may not be implementable on all native windowing systems, correct behavior for this method can be guaranteed only for lightweight Components. This method is not intended for general use, but exists instead as a hook for lightweight component libraries, such as Swing. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
Params:
  • temporary – true if the focus change is temporary,
       such as when the window loses the focus; for
       more information on temporary focus changes see the
Focus Specification
See Also:
Returns:false if the focus change request is guaranteed to fail; true if it is likely to succeed
Since:1.4
/**
     * Requests that this {@code Component} get the input focus,
     * and that this {@code Component}'s top-level ancestor
     * become the focused {@code Window}. This component must be
     * displayable, focusable, visible and all of its ancestors (with
     * the exception of the top-level Window) must be visible for the
     * request to be granted. Every effort will be made to honor the
     * request; however, in some cases it may be impossible to do
     * so. Developers must never assume that this component is the
     * focus owner until this component receives a FOCUS_GAINED
     * event. If this request is denied because this component's
     * top-level window cannot become the focused window, the request
     * will be remembered and will be granted when the window is later
     * focused by the user.
     * <p>
     * This method returns a boolean value. If {@code false} is returned,
     * the request is <b>guaranteed to fail</b>. If {@code true} is
     * returned, the request will succeed <b>unless</b> it is vetoed, or an
     * extraordinary event, such as disposal of the component's peer, occurs
     * before the request can be granted by the native windowing system. Again,
     * while a return value of {@code true} indicates that the request is
     * likely to succeed, developers must never assume that this component is
     * the focus owner until this component receives a FOCUS_GAINED event.
     * <p>
     * This method cannot be used to set the focus owner to no component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner}
     * instead.
     * <p>
     * Because the focus behavior of this method is platform-dependent,
     * developers are strongly encouraged to use
     * {@code requestFocusInWindow} when possible.
     * <p>
     * Every effort will be made to ensure that {@code FocusEvent}s
     * generated as a
     * result of this request will have the specified temporary value. However,
     * because specifying an arbitrary temporary state may not be implementable
     * on all native windowing systems, correct behavior for this method can be
     * guaranteed only for lightweight {@code Component}s.
     * This method is not intended
     * for general use, but exists instead as a hook for lightweight component
     * libraries, such as Swing.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @param temporary true if the focus change is temporary,
     *        such as when the window loses the focus; for
     *        more information on temporary focus changes see the
     *<a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
     * @return {@code false} if the focus change request is guaranteed to
     *         fail; {@code true} if it is likely to succeed
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 1.4
     */
    protected boolean requestFocus(boolean temporary) {
        return requestFocusHelper(temporary, true);
    }

    
Requests by the reason of cause that this Component get the input focus, and that this Component's top-level ancestor become the focused Window. This component must be displayable, focusable, visible and all of its ancestors (with the exception of the top-level Window) must be visible for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. If this request is denied because this component's top-level window cannot become the focused window, the request will be remembered and will be granted when the window is later focused by the user. 
 This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. 

The focus request effect may also depend on the provided
cause value. If this request is succeed the {FocusEvent}
generated in the result will receive the cause value specified as the
argument of the method.

 This method cannot be used to set the focus owner to no component at all. Use KeyboardFocusManager.clearGlobalFocusOwner instead. 
 Because the focus behavior of this method is platform-dependent, developers are strongly encouraged to use requestFocusInWindow when possible. 
 Every effort will be made to ensure that FocusEvents generated as a result of this request will have the specified temporary value. However, because specifying an arbitrary temporary state may not be implementable on all native windowing systems, correct behavior for this method can be guaranteed only for lightweight Components. This method is not intended for general use, but exists instead as a hook for lightweight component libraries, such as Swing. 
 Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
Params:
  • temporary – true if the focus change is temporary,
       such as when the window loses the focus; for
       more information on temporary focus changes see the
Focus Specification
  • cause – the cause why the focus is requested
See Also:
Returns:false if the focus change request is guaranteed to fail; true if it is likely to succeed
Since:9
/**
     * Requests by the reason of {@code cause} that this {@code Component} get
     * the input focus, and that this {@code Component}'s top-level ancestor
     * become the focused {@code Window}. This component must be
     * displayable, focusable, visible and all of its ancestors (with
     * the exception of the top-level Window) must be visible for the
     * request to be granted. Every effort will be made to honor the
     * request; however, in some cases it may be impossible to do
     * so. Developers must never assume that this component is the
     * focus owner until this component receives a FOCUS_GAINED
     * event. If this request is denied because this component's
     * top-level window cannot become the focused window, the request
     * will be remembered and will be granted when the window is later
     * focused by the user.
     * <p>
     * This method returns a boolean value. If {@code false} is returned,
     * the request is <b>guaranteed to fail</b>. If {@code true} is
     * returned, the request will succeed <b>unless</b> it is vetoed, or an
     * extraordinary event, such as disposal of the component's peer, occurs
     * before the request can be granted by the native windowing system. Again,
     * while a return value of {@code true} indicates that the request is
     * likely to succeed, developers must never assume that this component is
     * the focus owner until this component receives a FOCUS_GAINED event.
     * <p>
     * The focus request effect may also depend on the provided
     * cause value. If this request is succeed the {FocusEvent}
     * generated in the result will receive the cause value specified as the
     * argument of the method.
     * <p>
     * This method cannot be used to set the focus owner to no component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner}
     * instead.
     * <p>
     * Because the focus behavior of this method is platform-dependent,
     * developers are strongly encouraged to use
     * {@code requestFocusInWindow} when possible.
     * <p>
     * Every effort will be made to ensure that {@code FocusEvent}s
     * generated as a
     * result of this request will have the specified temporary value. However,
     * because specifying an arbitrary temporary state may not be implementable
     * on all native windowing systems, correct behavior for this method can be
     * guaranteed only for lightweight {@code Component}s.
     * This method is not intended
     * for general use, but exists instead as a hook for lightweight component
     * libraries, such as Swing.
     * <p>
     * Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @param temporary true if the focus change is temporary,
     *        such as when the window loses the focus; for
     *        more information on temporary focus changes see the
     *<a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
     *
     * @param  cause the cause why the focus is requested
     * @return {@code false} if the focus change request is guaranteed to
     *         fail; {@code true} if it is likely to succeed
     * @see FocusEvent
     * @see FocusEvent.Cause
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 9
     */
    protected boolean requestFocus(boolean temporary, FocusEvent.Cause cause) {
        return requestFocusHelper(temporary, true, cause);
    }

    
Requests that this Component get the input focus, if this
Component's top-level ancestor is already the focused
Window. This component must be displayable, focusable, visible
and all of its ancestors (with the exception of the top-level
Window) must be visible for the request to be granted. Every
effort will be made to honor the request; however, in some
cases it may be impossible to do so. Developers must never
assume that this Component is the focus owner until this
Component receives a FOCUS_GAINED event.

 This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the Component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event. 
 This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead. 
 The focus behavior of this method can be implemented uniformly across platforms, and thus developers are strongly encouraged to use this method over requestFocus when possible. Code which relies on requestFocus may exhibit different focus behavior on different platforms. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
See Also:
Returns:false if the focus change request is guaranteed to fail; true if it is likely to succeed
Since:1.4
/**
     * Requests that this Component get the input focus, if this
     * Component's top-level ancestor is already the focused
     * Window. This component must be displayable, focusable, visible
     * and all of its ancestors (with the exception of the top-level
     * Window) must be visible for the request to be granted. Every
     * effort will be made to honor the request; however, in some
     * cases it may be impossible to do so. Developers must never
     * assume that this Component is the focus owner until this
     * Component receives a FOCUS_GAINED event.
     * <p>
     * This method returns a boolean value. If {@code false} is returned,
     * the request is <b>guaranteed to fail</b>. If {@code true} is
     * returned, the request will succeed <b>unless</b> it is vetoed, or an
     * extraordinary event, such as disposal of the Component's peer, occurs
     * before the request can be granted by the native windowing system. Again,
     * while a return value of {@code true} indicates that the request is
     * likely to succeed, developers must never assume that this Component is
     * the focus owner until this Component receives a FOCUS_GAINED event.
     * <p>
     * This method cannot be used to set the focus owner to no Component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner()}
     * instead.
     * <p>
     * The focus behavior of this method can be implemented uniformly across
     * platforms, and thus developers are strongly encouraged to use this
     * method over {@code requestFocus} when possible. Code which relies
     * on {@code requestFocus} may exhibit different focus behavior on
     * different platforms.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @return {@code false} if the focus change request is guaranteed to
     *         fail; {@code true} if it is likely to succeed
     * @see #requestFocus
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 1.4
     */
    public boolean requestFocusInWindow() {
        return requestFocusHelper(false, false);
    }

    
Requests by the reason of cause that this Component get the input focus, if this Component's top-level ancestor is already the focused Window. This component must be displayable, focusable, visible and all of its ancestors (with the exception of the top-level Window) must be visible for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event. 
 This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the Component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this Component is the focus owner until this Component receives a FOCUS_GAINED event. 
 The focus request effect may also depend on the provided cause value. If this request is succeed the FocusEvent generated in the result will receive the cause value specified as the argument of the method. 
 This method cannot be used to set the focus owner to no Component at all. Use KeyboardFocusManager.clearGlobalFocusOwner() instead. 
 The focus behavior of this method can be implemented uniformly across platforms, and thus developers are strongly encouraged to use this method over requestFocus(FocusEvent.Cause) when possible. Code which relies on requestFocus(FocusEvent.Cause) may exhibit different focus behavior on different platforms. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
Params:
  • cause – the cause why the focus is requested
See Also:
Returns:false if the focus change request is guaranteed to fail; true if it is likely to succeed
Since:9
/**
     * Requests by the reason of {@code cause} that this Component get the input
     * focus, if this Component's top-level ancestor is already the focused
     * Window. This component must be displayable, focusable, visible
     * and all of its ancestors (with the exception of the top-level
     * Window) must be visible for the request to be granted. Every
     * effort will be made to honor the request; however, in some
     * cases it may be impossible to do so. Developers must never
     * assume that this Component is the focus owner until this
     * Component receives a FOCUS_GAINED event.
     * <p>
     * This method returns a boolean value. If {@code false} is returned,
     * the request is <b>guaranteed to fail</b>. If {@code true} is
     * returned, the request will succeed <b>unless</b> it is vetoed, or an
     * extraordinary event, such as disposal of the Component's peer, occurs
     * before the request can be granted by the native windowing system. Again,
     * while a return value of {@code true} indicates that the request is
     * likely to succeed, developers must never assume that this Component is
     * the focus owner until this Component receives a FOCUS_GAINED event.
     * <p>
     * The focus request effect may also depend on the provided
     * cause value. If this request is succeed the {@code FocusEvent}
     * generated in the result will receive the cause value specified as the
     * argument of the method.
     * <p>
     * This method cannot be used to set the focus owner to no Component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner()}
     * instead.
     * <p>
     * The focus behavior of this method can be implemented uniformly across
     * platforms, and thus developers are strongly encouraged to use this
     * method over {@code requestFocus(FocusEvent.Cause)} when possible.
     * Code which relies on {@code requestFocus(FocusEvent.Cause)} may exhibit
     * different focus behavior on different platforms.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @param  cause the cause why the focus is requested
     * @return {@code false} if the focus change request is guaranteed to
     *         fail; {@code true} if it is likely to succeed
     * @see #requestFocus(FocusEvent.Cause)
     * @see FocusEvent
     * @see FocusEvent.Cause
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 9
     */
    public boolean requestFocusInWindow(FocusEvent.Cause cause) {
        return requestFocusHelper(false, false, cause);
    }

    
Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window. This component must be displayable, focusable, visible and all of its ancestors (with the exception of the top-level Window) must be visible for the request to be granted. Every effort will be made to honor the request; however, in some cases it may be impossible to do so. Developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. 
 This method returns a boolean value. If false is returned, the request is guaranteed to fail. If true is returned, the request will succeed unless it is vetoed, or an extraordinary event, such as disposal of the component's peer, occurs before the request can be granted by the native windowing system. Again, while a return value of true indicates that the request is likely to succeed, developers must never assume that this component is the focus owner until this component receives a FOCUS_GAINED event. 
 This method cannot be used to set the focus owner to no component at all. Use KeyboardFocusManager.clearGlobalFocusOwner instead. 
 The focus behavior of this method can be implemented uniformly across platforms, and thus developers are strongly encouraged to use this method over requestFocus when possible. Code which relies on requestFocus may exhibit different focus behavior on different platforms. 
 Every effort will be made to ensure that FocusEvents generated as a result of this request will have the specified temporary value. However, because specifying an arbitrary temporary state may not be implementable on all native windowing systems, correct behavior for this method can be guaranteed only for lightweight components. This method is not intended for general use, but exists instead as a hook for lightweight component libraries, such as Swing. 
Note: Not all focus transfers result from invoking this method. As such, a component may receive focus without this or any of the other requestFocus methods of Component being invoked. 
Params:
  • temporary – true if the focus change is temporary,
       such as when the window loses the focus; for
       more information on temporary focus changes see the
Focus Specification
See Also:
Returns:false if the focus change request is guaranteed to fail; true if it is likely to succeed
Since:1.4
/**
     * Requests that this {@code Component} get the input focus,
     * if this {@code Component}'s top-level ancestor is already
     * the focused {@code Window}.  This component must be
     * displayable, focusable, visible and all of its ancestors (with
     * the exception of the top-level Window) must be visible for the
     * request to be granted. Every effort will be made to honor the
     * request; however, in some cases it may be impossible to do
     * so. Developers must never assume that this component is the
     * focus owner until this component receives a FOCUS_GAINED event.
     * <p>
     * This method returns a boolean value. If {@code false} is returned,
     * the request is <b>guaranteed to fail</b>. If {@code true} is
     * returned, the request will succeed <b>unless</b> it is vetoed, or an
     * extraordinary event, such as disposal of the component's peer, occurs
     * before the request can be granted by the native windowing system. Again,
     * while a return value of {@code true} indicates that the request is
     * likely to succeed, developers must never assume that this component is
     * the focus owner until this component receives a FOCUS_GAINED event.
     * <p>
     * This method cannot be used to set the focus owner to no component at
     * all. Use {@code KeyboardFocusManager.clearGlobalFocusOwner}
     * instead.
     * <p>
     * The focus behavior of this method can be implemented uniformly across
     * platforms, and thus developers are strongly encouraged to use this
     * method over {@code requestFocus} when possible. Code which relies
     * on {@code requestFocus} may exhibit different focus behavior on
     * different platforms.
     * <p>
     * Every effort will be made to ensure that {@code FocusEvent}s
     * generated as a
     * result of this request will have the specified temporary value. However,
     * because specifying an arbitrary temporary state may not be implementable
     * on all native windowing systems, correct behavior for this method can be
     * guaranteed only for lightweight components. This method is not intended
     * for general use, but exists instead as a hook for lightweight component
     * libraries, such as Swing.
     *
     * <p>Note: Not all focus transfers result from invoking this method. As
     * such, a component may receive focus without this or any of the other
     * {@code requestFocus} methods of {@code Component} being invoked.
     *
     * @param temporary true if the focus change is temporary,
     *        such as when the window loses the focus; for
     *        more information on temporary focus changes see the
     *<a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
     * @return {@code false} if the focus change request is guaranteed to
     *         fail; {@code true} if it is likely to succeed
     * @see #requestFocus
     * @see java.awt.event.FocusEvent
     * @see #addFocusListener
     * @see #isFocusable
     * @see #isDisplayable
     * @see KeyboardFocusManager#clearGlobalFocusOwner
     * @since 1.4
     */
    protected boolean requestFocusInWindow(boolean temporary) {
        return requestFocusHelper(temporary, false);
    }

    boolean requestFocusInWindow(boolean temporary, FocusEvent.Cause cause) {
        return requestFocusHelper(temporary, false, cause);
    }

    final boolean requestFocusHelper(boolean temporary,
                                     boolean focusedWindowChangeAllowed) {
        return requestFocusHelper(temporary, focusedWindowChangeAllowed, FocusEvent.Cause.UNKNOWN);
    }

    final boolean requestFocusHelper(boolean temporary,
                                     boolean focusedWindowChangeAllowed,
                                     FocusEvent.Cause cause)
    {
        // 1) Check if the event being dispatched is a system-generated mouse event.
        AWTEvent currentEvent = EventQueue.getCurrentEvent();
        if (currentEvent instanceof MouseEvent &&
            SunToolkit.isSystemGenerated(currentEvent))
        {
            // 2) Sanity check: if the mouse event component source belongs to the same containing window.
            Component source = ((MouseEvent)currentEvent).getComponent();
            if (source == null || source.getContainingWindow() == getContainingWindow()) {
                focusLog.finest("requesting focus by mouse event \"in window\"");

                // If both the conditions are fulfilled the focus request should be strictly
                // bounded by the toplevel window. It's assumed that the mouse event activates
                // the window (if it wasn't active) and this makes it possible for a focus
                // request with a strong in-window requirement to change focus in the bounds
                // of the toplevel. If, by any means, due to asynchronous nature of the event
                // dispatching mechanism, the window happens to be natively inactive by the time
                // this focus request is eventually handled, it should not re-activate the
                // toplevel. Otherwise the result may not meet user expectations. See 6981400.
                focusedWindowChangeAllowed = false;
            }
        }
        if (!isRequestFocusAccepted(temporary, focusedWindowChangeAllowed, cause)) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("requestFocus is not accepted");
            }
            return false;
        }
        // Update most-recent map
        KeyboardFocusManager.setMostRecentFocusOwner(this);

        Component window = this;
        while ( (window != null) && !(window instanceof Window)) {
            if (!window.isVisible()) {
                if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                    focusLog.finest("component is recursively invisible");
                }
                return false;
            }
            window = window.parent;
        }

        ComponentPeer peer = this.peer;
        Component heavyweight = (peer instanceof LightweightPeer)
            ? getNativeContainer() : this;
        if (heavyweight == null || !heavyweight.isVisible()) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Component is not a part of visible hierarchy");
            }
            return false;
        }
        peer = heavyweight.peer;
        if (peer == null) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Peer is null");
            }
            return false;
        }

        // Focus this Component
        long time = 0;
        if (EventQueue.isDispatchThread()) {
            time = Toolkit.getEventQueue().getMostRecentKeyEventTime();
        } else {
            // A focus request made from outside EDT should not be associated with any event
            // and so its time stamp is simply set to the current time.
            time = System.currentTimeMillis();
        }

        boolean success = peer.requestFocus
            (this, temporary, focusedWindowChangeAllowed, time, cause);
        if (!success) {
            KeyboardFocusManager.getCurrentKeyboardFocusManager
                (appContext).dequeueKeyEvents(time, this);
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Peer request failed");
            }
        } else {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Pass for " + this);
            }
        }
        return success;
    }

    private boolean isRequestFocusAccepted(boolean temporary,
                                           boolean focusedWindowChangeAllowed,
                                           FocusEvent.Cause cause)
    {
        if (!isFocusable() || !isVisible()) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Not focusable or not visible");
            }
            return false;
        }

        ComponentPeer peer = this.peer;
        if (peer == null) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("peer is null");
            }
            return false;
        }

        Window window = getContainingWindow();
        if (window == null || !window.isFocusableWindow()) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("Component doesn't have toplevel");
            }
            return false;
        }

        // We have passed all regular checks for focus request,
        // now let's call RequestFocusController and see what it says.
        Component focusOwner = KeyboardFocusManager.getMostRecentFocusOwner(window);
        if (focusOwner == null) {
            // sometimes most recent focus owner may be null, but focus owner is not
            // e.g. we reset most recent focus owner if user removes focus owner
            focusOwner = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
            if (focusOwner != null && focusOwner.getContainingWindow() != window) {
                focusOwner = null;
            }
        }

        if (focusOwner == this || focusOwner == null) {
            // Controller is supposed to verify focus transfers and for this it
            // should know both from and to components.  And it shouldn't verify
            // transfers from when these components are equal.
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("focus owner is null or this");
            }
            return true;
        }

        if (FocusEvent.Cause.ACTIVATION == cause) {
            // we shouldn't call RequestFocusController in case we are
            // in activation.  We do request focus on component which
            // has got temporary focus lost and then on component which is
            // most recent focus owner.  But most recent focus owner can be
            // changed by requestFocusXXX() call only, so this transfer has
            // been already approved.
            if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
                focusLog.finest("cause is activation");
            }
            return true;
        }

        boolean ret = Component.requestFocusController.acceptRequestFocus(focusOwner,
                                                                          this,
                                                                          temporary,
                                                                          focusedWindowChangeAllowed,
                                                                          cause);
        if (focusLog.isLoggable(PlatformLogger.Level.FINEST)) {
            focusLog.finest("RequestFocusController returns {0}", ret);
        }

        return ret;
    }

    private static RequestFocusController requestFocusController = new DummyRequestFocusController();

    // Swing access this method through reflection to implement InputVerifier's functionality.
    // Perhaps, we should make this method public (later ;)
    private static class DummyRequestFocusController implements RequestFocusController {
        public boolean acceptRequestFocus(Component from, Component to,
                                          boolean temporary, boolean focusedWindowChangeAllowed,
                                          FocusEvent.Cause cause)
        {
            return true;
        }
    };

    static synchronized void setRequestFocusController(RequestFocusController requestController)
    {
        if (requestController == null) {
            requestFocusController = new DummyRequestFocusController();
        } else {
            requestFocusController = requestController;
        }
    }

    
Returns the Container which is the focus cycle root of this Component's
focus traversal cycle. Each focus traversal cycle has only a single
focus cycle root and each Component which is not a Container belongs to
only a single focus traversal cycle. Containers which are focus cycle
roots belong to two cycles: one rooted at the Container itself, and one
rooted at the Container's nearest focus-cycle-root ancestor. For such
Containers, this method will return the Container's nearest focus-cycle-
root ancestor.

See Also:
Returns:this Component's nearest focus-cycle-root ancestor
Since:1.4
/**
     * Returns the Container which is the focus cycle root of this Component's
     * focus traversal cycle. Each focus traversal cycle has only a single
     * focus cycle root and each Component which is not a Container belongs to
     * only a single focus traversal cycle. Containers which are focus cycle
     * roots belong to two cycles: one rooted at the Container itself, and one
     * rooted at the Container's nearest focus-cycle-root ancestor. For such
     * Containers, this method will return the Container's nearest focus-cycle-
     * root ancestor.
     *
     * @return this Component's nearest focus-cycle-root ancestor
     * @see Container#isFocusCycleRoot()
     * @since 1.4
     */
    public Container getFocusCycleRootAncestor() {
        Container rootAncestor = this.parent;
        while (rootAncestor != null && !rootAncestor.isFocusCycleRoot()) {
            rootAncestor = rootAncestor.parent;
        }
        return rootAncestor;
    }

    
Returns whether the specified Container is the focus cycle root of this
Component's focus traversal cycle. Each focus traversal cycle has only
a single focus cycle root and each Component which is not a Container
belongs to only a single focus traversal cycle.

Params:
  • container – the Container to be tested
See Also:
Returns:true if the specified Container is a focus-cycle- root of this Component; false otherwise
Since:1.4
/**
     * Returns whether the specified Container is the focus cycle root of this
     * Component's focus traversal cycle. Each focus traversal cycle has only
     * a single focus cycle root and each Component which is not a Container
     * belongs to only a single focus traversal cycle.
     *
     * @param container the Container to be tested
     * @return {@code true} if the specified Container is a focus-cycle-
     *         root of this Component; {@code false} otherwise
     * @see Container#isFocusCycleRoot()
     * @since 1.4
     */
    public boolean isFocusCycleRoot(Container container) {
        Container rootAncestor = getFocusCycleRootAncestor();
        return (rootAncestor == container);
    }

    Container getTraversalRoot() {
        return getFocusCycleRootAncestor();
    }

    
Transfers the focus to the next component, as though this Component were
the focus owner.

See Also:
  • requestFocus()
Since:    1.1
/**
     * Transfers the focus to the next component, as though this Component were
     * the focus owner.
     * @see       #requestFocus()
     * @since     1.1
     */
    public void transferFocus() {
        nextFocus();
    }

    
Deprecated:As of JDK version 1.1,
replaced by transferFocus().
/**
     * @deprecated As of JDK version 1.1,
     * replaced by transferFocus().
     */
    @Deprecated
    public void nextFocus() {
        transferFocus(false);
    }

    boolean transferFocus(boolean clearOnFailure) {
        if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
            focusLog.finer("clearOnFailure = " + clearOnFailure);
        }
        Component toFocus = getNextFocusCandidate();
        boolean res = false;
        if (toFocus != null && !toFocus.isFocusOwner() && toFocus != this) {
            res = toFocus.requestFocusInWindow(FocusEvent.Cause.TRAVERSAL_FORWARD);
        }
        if (clearOnFailure && !res) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
                focusLog.finer("clear global focus owner");
            }
            KeyboardFocusManager.getCurrentKeyboardFocusManager().clearGlobalFocusOwnerPriv();
        }
        if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
            focusLog.finer("returning result: " + res);
        }
        return res;
    }

    @SuppressWarnings("deprecation")
    final Component getNextFocusCandidate() {
        Container rootAncestor = getTraversalRoot();
        Component comp = this;
        while (rootAncestor != null &&
               !(rootAncestor.isShowing() && rootAncestor.canBeFocusOwner()))
        {
            comp = rootAncestor;
            rootAncestor = comp.getFocusCycleRootAncestor();
        }
        if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
            focusLog.finer("comp = " + comp + ", root = " + rootAncestor);
        }
        Component candidate = null;
        if (rootAncestor != null) {
            FocusTraversalPolicy policy = rootAncestor.getFocusTraversalPolicy();
            Component toFocus = policy.getComponentAfter(rootAncestor, comp);
            if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
                focusLog.finer("component after is " + toFocus);
            }
            if (toFocus == null) {
                toFocus = policy.getDefaultComponent(rootAncestor);
                if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
                    focusLog.finer("default component is " + toFocus);
                }
            }
            if (toFocus == null) {
                Applet applet = EmbeddedFrame.getAppletIfAncestorOf(this);
                if (applet != null) {
                    toFocus = applet;
                }
            }
            candidate = toFocus;
        }
        if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
            focusLog.finer("Focus transfer candidate: " + candidate);
        }
        return candidate;
    }

    
Transfers the focus to the previous component, as though this Component
were the focus owner.

See Also:
  • requestFocus()
Since:    1.4
/**
     * Transfers the focus to the previous component, as though this Component
     * were the focus owner.
     * @see       #requestFocus()
     * @since     1.4
     */
    public void transferFocusBackward() {
        transferFocusBackward(false);
    }

    boolean transferFocusBackward(boolean clearOnFailure) {
        Container rootAncestor = getTraversalRoot();
        Component comp = this;
        while (rootAncestor != null &&
               !(rootAncestor.isShowing() && rootAncestor.canBeFocusOwner()))
        {
            comp = rootAncestor;
            rootAncestor = comp.getFocusCycleRootAncestor();
        }
        boolean res = false;
        if (rootAncestor != null) {
            FocusTraversalPolicy policy = rootAncestor.getFocusTraversalPolicy();
            Component toFocus = policy.getComponentBefore(rootAncestor, comp);
            if (toFocus == null) {
                toFocus = policy.getDefaultComponent(rootAncestor);
            }
            if (toFocus != null) {
                res = toFocus.requestFocusInWindow(FocusEvent.Cause.TRAVERSAL_BACKWARD);
            }
        }
        if (clearOnFailure && !res) {
            if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
                focusLog.finer("clear global focus owner");
            }
            KeyboardFocusManager.getCurrentKeyboardFocusManager().clearGlobalFocusOwnerPriv();
        }
        if (focusLog.isLoggable(PlatformLogger.Level.FINER)) {
            focusLog.finer("returning result: " + res);
        }
        return res;
    }

    
Transfers the focus up one focus traversal cycle. Typically, the focus
owner is set to this Component's focus cycle root, and the current focus
cycle root is set to the new focus owner's focus cycle root. If,
however, this Component's focus cycle root is a Window, then the focus
owner is set to the focus cycle root's default Component to focus, and
the current focus cycle root is unchanged.

See Also:
Since:    1.4
/**
     * Transfers the focus up one focus traversal cycle. Typically, the focus
     * owner is set to this Component's focus cycle root, and the current focus
     * cycle root is set to the new focus owner's focus cycle root. If,
     * however, this Component's focus cycle root is a Window, then the focus
     * owner is set to the focus cycle root's default Component to focus, and
     * the current focus cycle root is unchanged.
     *
     * @see       #requestFocus()
     * @see       Container#isFocusCycleRoot()
     * @see       Container#setFocusCycleRoot(boolean)
     * @since     1.4
     */
    public void transferFocusUpCycle() {
        Container rootAncestor;
        for (rootAncestor = getFocusCycleRootAncestor();
             rootAncestor != null && !(rootAncestor.isShowing() &&
                                       rootAncestor.isFocusable() &&
                                       rootAncestor.isEnabled());
             rootAncestor = rootAncestor.getFocusCycleRootAncestor()) {
        }

        if (rootAncestor != null) {
            Container rootAncestorRootAncestor =
                rootAncestor.getFocusCycleRootAncestor();
            Container fcr = (rootAncestorRootAncestor != null) ?
                rootAncestorRootAncestor : rootAncestor;

            KeyboardFocusManager.getCurrentKeyboardFocusManager().
                setGlobalCurrentFocusCycleRootPriv(fcr);
            rootAncestor.requestFocus(FocusEvent.Cause.TRAVERSAL_UP);
        } else {
            Window window = getContainingWindow();

            if (window != null) {
                Component toFocus = window.getFocusTraversalPolicy().
                    getDefaultComponent(window);
                if (toFocus != null) {
                    KeyboardFocusManager.getCurrentKeyboardFocusManager().
                        setGlobalCurrentFocusCycleRootPriv(window);
                    toFocus.requestFocus(FocusEvent.Cause.TRAVERSAL_UP);
                }
            }
        }
    }

    
Returns true if this Component is the focus owner. This method is obsolete, and has been replaced by isFocusOwner(). 
Returns:true if this Component is the focus owner; false otherwise
Since:1.2
/**
     * Returns {@code true} if this {@code Component} is the
     * focus owner.  This method is obsolete, and has been replaced by
     * {@code isFocusOwner()}.
     *
     * @return {@code true} if this {@code Component} is the
     *         focus owner; {@code false} otherwise
     * @since 1.2
     */
    public boolean hasFocus() {
        return (KeyboardFocusManager.getCurrentKeyboardFocusManager().
                getFocusOwner() == this);
    }

    
Returns true if this Component is the focus owner. 
Returns:true if this Component is the focus owner; false otherwise
Since:1.4
/**
     * Returns {@code true} if this {@code Component} is the
     *    focus owner.
     *
     * @return {@code true} if this {@code Component} is the
     *     focus owner; {@code false} otherwise
     * @since 1.4
     */
    public boolean isFocusOwner() {
        return hasFocus();
    }

    /*
     * Used to disallow auto-focus-transfer on disposal of the focus owner
     * in the process of disposing its parent container.
     */
    private boolean autoFocusTransferOnDisposal = true;

    void setAutoFocusTransferOnDisposal(boolean value) {
        autoFocusTransferOnDisposal = value;
    }

    boolean isAutoFocusTransferOnDisposal() {
        return autoFocusTransferOnDisposal;
    }

    
Adds the specified popup menu to the component.

Params:
  • popup – the popup menu to be added to the component.
Throws:
See Also:
Since:    1.1
/**
     * Adds the specified popup menu to the component.
     * @param     popup the popup menu to be added to the component.
     * @see       #remove(MenuComponent)
     * @exception NullPointerException if {@code popup} is {@code null}
     * @since     1.1
     */
    public void add(PopupMenu popup) {
        synchronized (getTreeLock()) {
            if (popup.parent != null) {
                popup.parent.remove(popup);
            }
            if (popups == null) {
                popups = new Vector<PopupMenu>();
            }
            popups.addElement(popup);
            popup.parent = this;

            if (peer != null) {
                if (popup.peer == null) {
                    popup.addNotify();
                }
            }
        }
    }

    
Removes the specified popup menu from the component.

Params:
  • popup – the popup menu to be removed
See Also:
Since:    1.1
/**
     * Removes the specified popup menu from the component.
     * @param     popup the popup menu to be removed
     * @see       #add(PopupMenu)
     * @since     1.1
     */
    @SuppressWarnings("unchecked")
    public void remove(MenuComponent popup) {
        synchronized (getTreeLock()) {
            if (popups == null) {
                return;
            }
            int index = popups.indexOf(popup);
            if (index >= 0) {
                PopupMenu pmenu = (PopupMenu)popup;
                if (pmenu.peer != null) {
                    pmenu.removeNotify();
                }
                pmenu.parent = null;
                popups.removeElementAt(index);
                if (popups.size() == 0) {
                    popups = null;
                }
            }
        }
    }

    
Returns a string representing the state of this component. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null. 
Returns: a string representation of this component's state
Since:    1.0
/**
     * Returns a string representing the state of this component. This
     * method is intended to be used only for debugging purposes, and the
     * content and format of the returned string may vary between
     * implementations. The returned string may be empty but may not be
     * {@code null}.
     *
     * @return  a string representation of this component's state
     * @since     1.0
     */
    protected String paramString() {
        final String thisName = Objects.toString(getName(), "");
        final String invalid = isValid() ? "" : ",invalid";
        final String hidden = visible ? "" : ",hidden";
        final String disabled = enabled ? "" : ",disabled";
        return thisName + ',' + x + ',' + y + ',' + width + 'x' + height
                + invalid + hidden + disabled;
    }

    
Returns a string representation of this component and its values.

Returns:   a string representation of this component
Since:    1.0
/**
     * Returns a string representation of this component and its values.
     * @return    a string representation of this component
     * @since     1.0
     */
    public String toString() {
        return getClass().getName() + '[' + paramString() + ']';
    }

    
Prints a listing of this component to the standard system output stream System.out. 
See Also:
Since:    1.0
/**
     * Prints a listing of this component to the standard system output
     * stream {@code System.out}.
     * @see       java.lang.System#out
     * @since     1.0
     */
    public void list() {
        list(System.out, 0);
    }

    
Prints a listing of this component to the specified output
stream.

Params:
  • out –   a print stream
Throws:
Since:   1.0
/**
     * Prints a listing of this component to the specified output
     * stream.
     * @param    out   a print stream
     * @throws   NullPointerException if {@code out} is {@code null}
     * @since    1.0
     */
    public void list(PrintStream out) {
        list(out, 0);
    }

    
Prints out a list, starting at the specified indentation, to the
specified print stream.

Params:
  • out –      a print stream
  • indent –   number of spaces to indent
Throws:
See Also:
Since:    1.0
/**
     * Prints out a list, starting at the specified indentation, to the
     * specified print stream.
     * @param     out      a print stream
     * @param     indent   number of spaces to indent
     * @see       java.io.PrintStream#println(java.lang.Object)
     * @throws    NullPointerException if {@code out} is {@code null}
     * @since     1.0
     */
    public void list(PrintStream out, int indent) {
        for (int i = 0 ; i < indent ; i++) {
            out.print(" ");
        }
        out.println(this);
    }

    
Prints a listing to the specified print writer.

Params:
  • out –  the print writer to print to
Throws:
Since:1.1
/**
     * Prints a listing to the specified print writer.
     * @param  out  the print writer to print to
     * @throws NullPointerException if {@code out} is {@code null}
     * @since 1.1
     */
    public void list(PrintWriter out) {
        list(out, 0);
    }

    
Prints out a list, starting at the specified indentation, to
the specified print writer.

Params:
  • out – the print writer to print to
  • indent – the number of spaces to indent
Throws:
See Also:
Since:1.1
/**
     * Prints out a list, starting at the specified indentation, to
     * the specified print writer.
     * @param out the print writer to print to
     * @param indent the number of spaces to indent
     * @throws NullPointerException if {@code out} is {@code null}
     * @see       java.io.PrintStream#println(java.lang.Object)
     * @since 1.1
     */
    public void list(PrintWriter out, int indent) {
        for (int i = 0 ; i < indent ; i++) {
            out.print(" ");
        }
        out.println(this);
    }

    /*
     * Fetches the native container somewhere higher up in the component
     * tree that contains this component.
     */
    final Container getNativeContainer() {
        Container p = getContainer();
        while (p != null && p.peer instanceof LightweightPeer) {
            p = p.getContainer();
        }
        return p;
    }

    
Adds a PropertyChangeListener to the listener list. The listener is
registered for all bound properties of this class, including the
following:

    
   
  • this Component's font ("font")
    • 
   
  • this Component's background color ("background")
    • 
   
  • this Component's foreground color ("foreground")
    • 
   
  • this Component's focusability ("focusable")
    • 
   
  • this Component's focus traversal keys enabled state
       ("focusTraversalKeysEnabled")
    • 
   
  • this Component's Set of FORWARD_TRAVERSAL_KEYS
       ("forwardFocusTraversalKeys")
    • 
   
  • this Component's Set of BACKWARD_TRAVERSAL_KEYS
       ("backwardFocusTraversalKeys")
    • 
   
  • this Component's Set of UP_CYCLE_TRAVERSAL_KEYS
       ("upCycleFocusTraversalKeys")
    • 
   
  • this Component's preferred size ("preferredSize")
    • 
   
  • this Component's minimum size ("minimumSize")
    • 
   
  • this Component's maximum size ("maximumSize")
    • 
   
  • this Component's name ("name")
    • 

 Note that if this Component is inheriting a bound property, then no event will be fired in response to a change in the inherited property. 
 If listener is null, no exception is thrown and no action is performed. 
Params:
  • listener –  the property change listener to be added
See Also:
/**
     * Adds a PropertyChangeListener to the listener list. The listener is
     * registered for all bound properties of this class, including the
     * following:
     * <ul>
     *    <li>this Component's font ("font")</li>
     *    <li>this Component's background color ("background")</li>
     *    <li>this Component's foreground color ("foreground")</li>
     *    <li>this Component's focusability ("focusable")</li>
     *    <li>this Component's focus traversal keys enabled state
     *        ("focusTraversalKeysEnabled")</li>
     *    <li>this Component's Set of FORWARD_TRAVERSAL_KEYS
     *        ("forwardFocusTraversalKeys")</li>
     *    <li>this Component's Set of BACKWARD_TRAVERSAL_KEYS
     *        ("backwardFocusTraversalKeys")</li>
     *    <li>this Component's Set of UP_CYCLE_TRAVERSAL_KEYS
     *        ("upCycleFocusTraversalKeys")</li>
     *    <li>this Component's preferred size ("preferredSize")</li>
     *    <li>this Component's minimum size ("minimumSize")</li>
     *    <li>this Component's maximum size ("maximumSize")</li>
     *    <li>this Component's name ("name")</li>
     * </ul>
     * Note that if this {@code Component} is inheriting a bound property, then no
     * event will be fired in response to a change in the inherited property.
     * <p>
     * If {@code listener} is {@code null},
     * no exception is thrown and no action is performed.
     *
     * @param    listener  the property change listener to be added
     *
     * @see #removePropertyChangeListener
     * @see #getPropertyChangeListeners
     * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     */
    public void addPropertyChangeListener(
                                                       PropertyChangeListener listener) {
        synchronized (getObjectLock()) {
            if (listener == null) {
                return;
            }
            if (changeSupport == null) {
                changeSupport = new PropertyChangeSupport(this);
            }
            changeSupport.addPropertyChangeListener(listener);
        }
    }

    
Removes a PropertyChangeListener from the listener list. This method
should be used to remove PropertyChangeListeners that were registered
for all bound properties of this class.


If listener is null, no exception is thrown and no action is performed.

Params:
  • listener – the PropertyChangeListener to be removed
See Also:
/**
     * Removes a PropertyChangeListener from the listener list. This method
     * should be used to remove PropertyChangeListeners that were registered
     * for all bound properties of this class.
     * <p>
     * If listener is null, no exception is thrown and no action is performed.
     *
     * @param listener the PropertyChangeListener to be removed
     *
     * @see #addPropertyChangeListener
     * @see #getPropertyChangeListeners
     * @see #removePropertyChangeListener(java.lang.String,java.beans.PropertyChangeListener)
     */
    public void removePropertyChangeListener(
                                                          PropertyChangeListener listener) {
        synchronized (getObjectLock()) {
            if (listener == null || changeSupport == null) {
                return;
            }
            changeSupport.removePropertyChangeListener(listener);
        }
    }

    
Returns an array of all the property change listeners
registered on this component.

See Also:
Returns:all of this component's PropertyChangeListeners or an empty array if no property change listeners are currently registered
Since:   1.4
/**
     * Returns an array of all the property change listeners
     * registered on this component.
     *
     * @return all of this component's {@code PropertyChangeListener}s
     *         or an empty array if no property change
     *         listeners are currently registered
     *
     * @see      #addPropertyChangeListener
     * @see      #removePropertyChangeListener
     * @see      #getPropertyChangeListeners(java.lang.String)
     * @see      java.beans.PropertyChangeSupport#getPropertyChangeListeners
     * @since    1.4
     */
    public PropertyChangeListener[] getPropertyChangeListeners() {
        synchronized (getObjectLock()) {
            if (changeSupport == null) {
                return new PropertyChangeListener[0];
            }
            return changeSupport.getPropertyChangeListeners();
        }
    }

    
Adds a PropertyChangeListener to the listener list for a specific
property. The specified property may be user-defined, or one of the
following:

    
   
  • this Component's font ("font")
    • 
   
  • this Component's background color ("background")
    • 
   
  • this Component's foreground color ("foreground")
    • 
   
  • this Component's focusability ("focusable")
    • 
   
  • this Component's focus traversal keys enabled state
       ("focusTraversalKeysEnabled")
    • 
   
  • this Component's Set of FORWARD_TRAVERSAL_KEYS
       ("forwardFocusTraversalKeys")
    • 
   
  • this Component's Set of BACKWARD_TRAVERSAL_KEYS
       ("backwardFocusTraversalKeys")
    • 
   
  • this Component's Set of UP_CYCLE_TRAVERSAL_KEYS
       ("upCycleFocusTraversalKeys")
    • 

 Note that if this Component is inheriting a bound property, then no event will be fired in response to a change in the inherited property. 
 If propertyName or listener is null, no exception is thrown and no action is taken. 
Params:
  • propertyName – one of the property names listed above
  • listener – the property change listener to be added
See Also:
/**
     * Adds a PropertyChangeListener to the listener list for a specific
     * property. The specified property may be user-defined, or one of the
     * following:
     * <ul>
     *    <li>this Component's font ("font")</li>
     *    <li>this Component's background color ("background")</li>
     *    <li>this Component's foreground color ("foreground")</li>
     *    <li>this Component's focusability ("focusable")</li>
     *    <li>this Component's focus traversal keys enabled state
     *        ("focusTraversalKeysEnabled")</li>
     *    <li>this Component's Set of FORWARD_TRAVERSAL_KEYS
     *        ("forwardFocusTraversalKeys")</li>
     *    <li>this Component's Set of BACKWARD_TRAVERSAL_KEYS
     *        ("backwardFocusTraversalKeys")</li>
     *    <li>this Component's Set of UP_CYCLE_TRAVERSAL_KEYS
     *        ("upCycleFocusTraversalKeys")</li>
     * </ul>
     * Note that if this {@code Component} is inheriting a bound property, then no
     * event will be fired in response to a change in the inherited property.
     * <p>
     * If {@code propertyName} or {@code listener} is {@code null},
     * no exception is thrown and no action is taken.
     *
     * @param propertyName one of the property names listed above
     * @param listener the property change listener to be added
     *
     * @see #removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     * @see #getPropertyChangeListeners(java.lang.String)
     * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     */
    public void addPropertyChangeListener(
                                                       String propertyName,
                                                       PropertyChangeListener listener) {
        synchronized (getObjectLock()) {
            if (listener == null) {
                return;
            }
            if (changeSupport == null) {
                changeSupport = new PropertyChangeSupport(this);
            }
            changeSupport.addPropertyChangeListener(propertyName, listener);
        }
    }

    
Removes a PropertyChangeListener from the listener list for a specific property. This method should be used to remove PropertyChangeListeners that were registered for a specific bound property. 
 If propertyName or listener is null, no exception is thrown and no action is taken. 
Params:
  • propertyName – a valid property name
  • listener – the PropertyChangeListener to be removed
See Also:
/**
     * Removes a {@code PropertyChangeListener} from the listener
     * list for a specific property. This method should be used to remove
     * {@code PropertyChangeListener}s
     * that were registered for a specific bound property.
     * <p>
     * If {@code propertyName} or {@code listener} is {@code null},
     * no exception is thrown and no action is taken.
     *
     * @param propertyName a valid property name
     * @param listener the PropertyChangeListener to be removed
     *
     * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     * @see #getPropertyChangeListeners(java.lang.String)
     * @see #removePropertyChangeListener(java.beans.PropertyChangeListener)
     */
    public void removePropertyChangeListener(
                                                          String propertyName,
                                                          PropertyChangeListener listener) {
        synchronized (getObjectLock()) {
            if (listener == null || changeSupport == null) {
                return;
            }
            changeSupport.removePropertyChangeListener(propertyName, listener);
        }
    }

    
Returns an array of all the listeners which have been associated
with the named property.

Params:
  • propertyName – the property name
See Also:
Returns:all of the PropertyChangeListeners associated with the named property; if no such listeners have been added or if propertyName is null, an empty array is returned
Since:1.4
/**
     * Returns an array of all the listeners which have been associated
     * with the named property.
     *
     * @param  propertyName the property name
     * @return all of the {@code PropertyChangeListener}s associated with
     *         the named property; if no such listeners have been added or
     *         if {@code propertyName} is {@code null}, an empty
     *         array is returned
     *
     * @see #addPropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     * @see #removePropertyChangeListener(java.lang.String, java.beans.PropertyChangeListener)
     * @see #getPropertyChangeListeners
     * @since 1.4
     */
    public PropertyChangeListener[] getPropertyChangeListeners(String propertyName) {
        synchronized (getObjectLock()) {
            if (changeSupport == null) {
                return new PropertyChangeListener[0];
            }
            return changeSupport.getPropertyChangeListeners(propertyName);
        }
    }

    
Support for reporting bound property changes for Object properties.
This method can be called when a bound property has changed and it will
send the appropriate PropertyChangeEvent to any registered
PropertyChangeListeners.

Params:
  • propertyName – the property whose value has changed
  • oldValue – the property's previous value
  • newValue – the property's new value
/**
     * Support for reporting bound property changes for Object properties.
     * This method can be called when a bound property has changed and it will
     * send the appropriate PropertyChangeEvent to any registered
     * PropertyChangeListeners.
     *
     * @param propertyName the property whose value has changed
     * @param oldValue the property's previous value
     * @param newValue the property's new value
     */
    protected void firePropertyChange(String propertyName,
                                      Object oldValue, Object newValue) {
        PropertyChangeSupport changeSupport;
        synchronized (getObjectLock()) {
            changeSupport = this.changeSupport;
        }
        if (changeSupport == null ||
            (oldValue != null && newValue != null && oldValue.equals(newValue))) {
            return;
        }
        changeSupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    
Support for reporting bound property changes for boolean properties.
This method can be called when a bound property has changed and it will
send the appropriate PropertyChangeEvent to any registered
PropertyChangeListeners.

Params:
  • propertyName – the property whose value has changed
  • oldValue – the property's previous value
  • newValue – the property's new value
Since:1.4
/**
     * Support for reporting bound property changes for boolean properties.
     * This method can be called when a bound property has changed and it will
     * send the appropriate PropertyChangeEvent to any registered
     * PropertyChangeListeners.
     *
     * @param propertyName the property whose value has changed
     * @param oldValue the property's previous value
     * @param newValue the property's new value
     * @since 1.4
     */
    protected void firePropertyChange(String propertyName,
                                      boolean oldValue, boolean newValue) {
        PropertyChangeSupport changeSupport = this.changeSupport;
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        changeSupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    
Support for reporting bound property changes for integer properties.
This method can be called when a bound property has changed and it will
send the appropriate PropertyChangeEvent to any registered
PropertyChangeListeners.

Params:
  • propertyName – the property whose value has changed
  • oldValue – the property's previous value
  • newValue – the property's new value
Since:1.4
/**
     * Support for reporting bound property changes for integer properties.
     * This method can be called when a bound property has changed and it will
     * send the appropriate PropertyChangeEvent to any registered
     * PropertyChangeListeners.
     *
     * @param propertyName the property whose value has changed
     * @param oldValue the property's previous value
     * @param newValue the property's new value
     * @since 1.4
     */
    protected void firePropertyChange(String propertyName,
                                      int oldValue, int newValue) {
        PropertyChangeSupport changeSupport = this.changeSupport;
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        changeSupport.firePropertyChange(propertyName, oldValue, newValue);
    }

    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a byte)
  • newValue – the new value of the property (as a byte)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a byte)
     * @param newValue the new value of the property (as a byte)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, byte oldValue, byte newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Byte.valueOf(oldValue), Byte.valueOf(newValue));
    }

    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a char)
  • newValue – the new value of the property (as a char)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a char)
     * @param newValue the new value of the property (as a char)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, char oldValue, char newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Character.valueOf(oldValue), Character.valueOf(newValue));
    }

    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a short)
  • newValue – the new value of the property (as a short)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a short)
     * @param newValue the new value of the property (as a short)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, short oldValue, short newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Short.valueOf(oldValue), Short.valueOf(newValue));
    }


    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a long)
  • newValue – the new value of the property (as a long)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a long)
     * @param newValue the new value of the property (as a long)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, long oldValue, long newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Long.valueOf(oldValue), Long.valueOf(newValue));
    }

    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a float)
  • newValue – the new value of the property (as a float)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a float)
     * @param newValue the new value of the property (as a float)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, float oldValue, float newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Float.valueOf(oldValue), Float.valueOf(newValue));
    }

    
Reports a bound property change.

Params:
  • propertyName – the programmatic name of the property
         that was changed
  • oldValue – the old value of the property (as a double)
  • newValue – the new value of the property (as a double)
See Also:
Since:1.5
/**
     * Reports a bound property change.
     *
     * @param propertyName the programmatic name of the property
     *          that was changed
     * @param oldValue the old value of the property (as a double)
     * @param newValue the new value of the property (as a double)
     * @see #firePropertyChange(java.lang.String, java.lang.Object,
     *          java.lang.Object)
     * @since 1.5
     */
    public void firePropertyChange(String propertyName, double oldValue, double newValue) {
        if (changeSupport == null || oldValue == newValue) {
            return;
        }
        firePropertyChange(propertyName, Double.valueOf(oldValue), Double.valueOf(newValue));
    }


    // Serialization support.

    
Component Serialized Data Version.

@serial
/**
     * Component Serialized Data Version.
     *
     * @serial
     */
    private int componentSerializedDataVersion = 4;

    
This hack is for Swing serialization. It will invoke the Swing package private method compWriteObjectNotify. 
/**
     * This hack is for Swing serialization. It will invoke
     * the Swing package private method {@code compWriteObjectNotify}.
     */
    private void doSwingSerialization() {
        if (!(this instanceof JComponent)) {
            return;
        }
        @SuppressWarnings("deprecation")
        Package swingPackage = Package.getPackage("javax.swing");
        // For Swing serialization to correctly work Swing needs to
        // be notified before Component does it's serialization.  This
        // hack accommodates this.
        //
        // Swing classes MUST be loaded by the bootstrap class loader,
        // otherwise we don't consider them.
        for (Class<?> klass = Component.this.getClass(); klass != null;
                   klass = klass.getSuperclass()) {
            if (klass.getPackage() == swingPackage &&
                      klass.getClassLoader() == null) {

                SwingAccessor.getJComponentAccessor()
                        .compWriteObjectNotify((JComponent) this);
                return;
            }
        }
    }

    
Writes default serializable fields to stream.  Writes
a variety of serializable listeners as optional data.
The non-serializable listeners are detected and
no attempt is made to serialize them.

Params:
  • s – the ObjectOutputStream to write
See Also:
@serialDatanull terminated sequence of 0 or more pairs; the pair consists of a String and an Object; the String indicates the type of object and is one of the following (as of 1.4): componentListenerK indicating an ComponentListener object; focusListenerK indicating an FocusListener object; keyListenerK indicating an KeyListener object; mouseListenerK indicating an MouseListener object; mouseMotionListenerK indicating an MouseMotionListener object; inputMethodListenerK indicating an InputMethodListener object; hierarchyListenerK indicating an HierarchyListener object; hierarchyBoundsListenerK indicating an HierarchyBoundsListener object; mouseWheelListenerK indicating an MouseWheelListener object
@serialDataan optional ComponentOrientation (after inputMethodListener, as of 1.2)
/**
     * Writes default serializable fields to stream.  Writes
     * a variety of serializable listeners as optional data.
     * The non-serializable listeners are detected and
     * no attempt is made to serialize them.
     *
     * @param s the {@code ObjectOutputStream} to write
     * @serialData {@code null} terminated sequence of
     *   0 or more pairs; the pair consists of a {@code String}
     *   and an {@code Object}; the {@code String} indicates
     *   the type of object and is one of the following (as of 1.4):
     *   {@code componentListenerK} indicating an
     *     {@code ComponentListener} object;
     *   {@code focusListenerK} indicating an
     *     {@code FocusListener} object;
     *   {@code keyListenerK} indicating an
     *     {@code KeyListener} object;
     *   {@code mouseListenerK} indicating an
     *     {@code MouseListener} object;
     *   {@code mouseMotionListenerK} indicating an
     *     {@code MouseMotionListener} object;
     *   {@code inputMethodListenerK} indicating an
     *     {@code InputMethodListener} object;
     *   {@code hierarchyListenerK} indicating an
     *     {@code HierarchyListener} object;
     *   {@code hierarchyBoundsListenerK} indicating an
     *     {@code HierarchyBoundsListener} object;
     *   {@code mouseWheelListenerK} indicating an
     *     {@code MouseWheelListener} object
     * @serialData an optional {@code ComponentOrientation}
     *    (after {@code inputMethodListener}, as of 1.2)
     *
     * @see AWTEventMulticaster#save(java.io.ObjectOutputStream, java.lang.String, java.util.EventListener)
     * @see #componentListenerK
     * @see #focusListenerK
     * @see #keyListenerK
     * @see #mouseListenerK
     * @see #mouseMotionListenerK
     * @see #inputMethodListenerK
     * @see #hierarchyListenerK
     * @see #hierarchyBoundsListenerK
     * @see #mouseWheelListenerK
     * @see #readObject(ObjectInputStream)
     */
    private void writeObject(ObjectOutputStream s)
      throws IOException
    {
        doSwingSerialization();

        s.defaultWriteObject();

        AWTEventMulticaster.save(s, componentListenerK, componentListener);
        AWTEventMulticaster.save(s, focusListenerK, focusListener);
        AWTEventMulticaster.save(s, keyListenerK, keyListener);
        AWTEventMulticaster.save(s, mouseListenerK, mouseListener);
        AWTEventMulticaster.save(s, mouseMotionListenerK, mouseMotionListener);
        AWTEventMulticaster.save(s, inputMethodListenerK, inputMethodListener);

        s.writeObject(null);
        s.writeObject(componentOrientation);

        AWTEventMulticaster.save(s, hierarchyListenerK, hierarchyListener);
        AWTEventMulticaster.save(s, hierarchyBoundsListenerK,
                                 hierarchyBoundsListener);
        s.writeObject(null);

        AWTEventMulticaster.save(s, mouseWheelListenerK, mouseWheelListener);
        s.writeObject(null);

    }

    
Reads the ObjectInputStream and if it isn't null adds a listener to receive a variety of events fired by the component. Unrecognized keys or values will be ignored. 
Params:
  • s – the ObjectInputStream to read
See Also:
/**
     * Reads the {@code ObjectInputStream} and if it isn't
     * {@code null} adds a listener to receive a variety
     * of events fired by the component.
     * Unrecognized keys or values will be ignored.
     *
     * @param s the {@code ObjectInputStream} to read
     * @see #writeObject(ObjectOutputStream)
     */
    private void readObject(ObjectInputStream s)
      throws ClassNotFoundException, IOException
    {
        objectLock = new Object();

        acc = AccessController.getContext();

        s.defaultReadObject();

        appContext = AppContext.getAppContext();
        coalescingEnabled = checkCoalescing();
        if (componentSerializedDataVersion < 4) {
            // These fields are non-transient and rely on default
            // serialization. However, the default values are insufficient,
            // so we need to set them explicitly for object data streams prior
            // to 1.4.
            focusable = true;
            isFocusTraversableOverridden = FOCUS_TRAVERSABLE_UNKNOWN;
            initializeFocusTraversalKeys();
            focusTraversalKeysEnabled = true;
        }

        Object keyOrNull;
        while(null != (keyOrNull = s.readObject())) {
            String key = ((String)keyOrNull).intern();

            if (componentListenerK == key)
                addComponentListener((ComponentListener)(s.readObject()));

            else if (focusListenerK == key)
                addFocusListener((FocusListener)(s.readObject()));

            else if (keyListenerK == key)
                addKeyListener((KeyListener)(s.readObject()));

            else if (mouseListenerK == key)
                addMouseListener((MouseListener)(s.readObject()));

            else if (mouseMotionListenerK == key)
                addMouseMotionListener((MouseMotionListener)(s.readObject()));

            else if (inputMethodListenerK == key)
                addInputMethodListener((InputMethodListener)(s.readObject()));

            else // skip value for unrecognized key
                s.readObject();

        }

        // Read the component's orientation if it's present
        Object orient = null;

        try {
            orient = s.readObject();
        } catch (java.io.OptionalDataException e) {
            // JDK 1.1 instances will not have this optional data.
            // e.eof will be true to indicate that there is no more
            // data available for this object.
            // If e.eof is not true, throw the exception as it
            // might have been caused by reasons unrelated to
            // componentOrientation.

            if (!e.eof)  {
                throw (e);
            }
        }

        if (orient != null) {
            componentOrientation = (ComponentOrientation)orient;
        } else {
            componentOrientation = ComponentOrientation.UNKNOWN;
        }

        try {
            while(null != (keyOrNull = s.readObject())) {
                String key = ((String)keyOrNull).intern();

                if (hierarchyListenerK == key) {
                    addHierarchyListener((HierarchyListener)(s.readObject()));
                }
                else if (hierarchyBoundsListenerK == key) {
                    addHierarchyBoundsListener((HierarchyBoundsListener)
                                               (s.readObject()));
                }
                else {
                    // skip value for unrecognized key
                    s.readObject();
                }
            }
        } catch (java.io.OptionalDataException e) {
            // JDK 1.1/1.2 instances will not have this optional data.
            // e.eof will be true to indicate that there is no more
            // data available for this object.
            // If e.eof is not true, throw the exception as it
            // might have been caused by reasons unrelated to
            // hierarchy and hierarchyBounds listeners.

            if (!e.eof)  {
                throw (e);
            }
        }

        try {
            while (null != (keyOrNull = s.readObject())) {
                String key = ((String)keyOrNull).intern();

                if (mouseWheelListenerK == key) {
                    addMouseWheelListener((MouseWheelListener)(s.readObject()));
                }
                else {
                    // skip value for unrecognized key
                    s.readObject();
                }
            }
        } catch (java.io.OptionalDataException e) {
            // pre-1.3 instances will not have this optional data.
            // e.eof will be true to indicate that there is no more
            // data available for this object.
            // If e.eof is not true, throw the exception as it
            // might have been caused by reasons unrelated to
            // mouse wheel listeners

            if (!e.eof)  {
                throw (e);
            }
        }

        if (popups != null) {
            int npopups = popups.size();
            for (int i = 0 ; i < npopups ; i++) {
                PopupMenu popup = popups.elementAt(i);
                popup.parent = this;
            }
        }
    }

    
Sets the language-sensitive orientation that is to be used to order the elements or text within this component. Language-sensitive LayoutManager and Component subclasses will use this property to determine how to lay out and draw components. 
 At construction time, a component's orientation is set to ComponentOrientation.UNKNOWN, indicating that it has not been specified explicitly. The UNKNOWN orientation behaves the same as ComponentOrientation.LEFT_TO_RIGHT. 
 To set the orientation of a single component, use this method. To set the orientation of an entire component hierarchy, use applyComponentOrientation. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Author:Laura Werner, IBM
Params:
  • o – the orientation to be set
See Also:
/**
     * Sets the language-sensitive orientation that is to be used to order
     * the elements or text within this component.  Language-sensitive
     * {@code LayoutManager} and {@code Component}
     * subclasses will use this property to
     * determine how to lay out and draw components.
     * <p>
     * At construction time, a component's orientation is set to
     * {@code ComponentOrientation.UNKNOWN},
     * indicating that it has not been specified
     * explicitly.  The UNKNOWN orientation behaves the same as
     * {@code ComponentOrientation.LEFT_TO_RIGHT}.
     * <p>
     * To set the orientation of a single component, use this method.
     * To set the orientation of an entire component
     * hierarchy, use
     * {@link #applyComponentOrientation applyComponentOrientation}.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     * @param  o the orientation to be set
     *
     * @see ComponentOrientation
     * @see #invalidate
     *
     * @author Laura Werner, IBM
     */
    public void setComponentOrientation(ComponentOrientation o) {
        ComponentOrientation oldValue = componentOrientation;
        componentOrientation = o;

        // This is a bound property, so report the change to
        // any registered listeners.  (Cheap if there are none.)
        firePropertyChange("componentOrientation", oldValue, o);

        // This could change the preferred size of the Component.
        invalidateIfValid();
    }

    
Retrieves the language-sensitive orientation that is to be used to order the elements or text within this component. LayoutManager and Component subclasses that wish to respect orientation should call this method to get the component's orientation before performing layout or drawing. 
Author:Laura Werner, IBM
See Also:
Returns:the orientation to order the elements or text
/**
     * Retrieves the language-sensitive orientation that is to be used to order
     * the elements or text within this component.  {@code LayoutManager}
     * and {@code Component}
     * subclasses that wish to respect orientation should call this method to
     * get the component's orientation before performing layout or drawing.
     *
     * @return the orientation to order the elements or text
     * @see ComponentOrientation
     *
     * @author Laura Werner, IBM
     */
    public ComponentOrientation getComponentOrientation() {
        return componentOrientation;
    }

    
Sets the ComponentOrientation property of this component and all components contained within it. 

This method changes layout-related information, and therefore,
invalidates the component hierarchy.

Params:
  • orientation – the new component orientation of this component and
       the components contained within it.
Throws:
See Also:
Since:1.4
/**
     * Sets the {@code ComponentOrientation} property of this component
     * and all components contained within it.
     * <p>
     * This method changes layout-related information, and therefore,
     * invalidates the component hierarchy.
     *
     *
     * @param orientation the new component orientation of this component and
     *        the components contained within it.
     * @exception NullPointerException if {@code orientation} is null.
     * @see #setComponentOrientation
     * @see #getComponentOrientation
     * @see #invalidate
     * @since 1.4
     */
    public void applyComponentOrientation(ComponentOrientation orientation) {
        if (orientation == null) {
            throw new NullPointerException();
        }
        setComponentOrientation(orientation);
    }

    final boolean canBeFocusOwner() {
        // It is enabled, visible, focusable.
        if (isEnabled() && isDisplayable() && isVisible() && isFocusable()) {
            return true;
        }
        return false;
    }

    
Checks that this component meets the prerequisites to be focus owner:
- it is enabled, visible, focusable
- it's parents are all enabled and showing
- top-level window is focusable
- if focus cycle root has DefaultFocusTraversalPolicy then it also checks that this policy accepts
this component as focus owner

Since:1.5
/**
     * Checks that this component meets the prerequisites to be focus owner:
     * - it is enabled, visible, focusable
     * - it's parents are all enabled and showing
     * - top-level window is focusable
     * - if focus cycle root has DefaultFocusTraversalPolicy then it also checks that this policy accepts
     * this component as focus owner
     * @since 1.5
     */
    final boolean canBeFocusOwnerRecursively() {
        // - it is enabled, visible, focusable
        if (!canBeFocusOwner()) {
            return false;
        }

        // - it's parents are all enabled and showing
        synchronized(getTreeLock()) {
            if (parent != null) {
                return parent.canContainFocusOwner(this);
            }
        }
        return true;
    }

    
Fix the location of the HW component in a LW container hierarchy.

/**
     * Fix the location of the HW component in a LW container hierarchy.
     */
    final void relocateComponent() {
        synchronized (getTreeLock()) {
            if (peer == null) {
                return;
            }
            int nativeX = x;
            int nativeY = y;
            for (Component cont = getContainer();
                    cont != null && cont.isLightweight();
                    cont = cont.getContainer())
            {
                nativeX += cont.x;
                nativeY += cont.y;
            }
            peer.setBounds(nativeX, nativeY, width, height,
                    ComponentPeer.SET_LOCATION);
        }
    }

    
Returns the Window ancestor of the component. 
Returns:Window ancestor of the component or component by itself if it is Window;
        null, if component is not a part of window hierarchy
/**
     * Returns the {@code Window} ancestor of the component.
     * @return Window ancestor of the component or component by itself if it is Window;
     *         null, if component is not a part of window hierarchy
     */
    Window getContainingWindow() {
        return SunToolkit.getContainingWindow(this);
    }

    
Initialize JNI field and method IDs

/**
     * Initialize JNI field and method IDs
     */
    private static native void initIDs();

    /*
     * --- Accessibility Support ---
     *
     *  Component will contain all of the methods in interface Accessible,
     *  though it won't actually implement the interface - that will be up
     *  to the individual objects which extend Component.
     */

    
The AccessibleContext associated with this Component. 
/**
     * The {@code AccessibleContext} associated with this {@code Component}.
     */
    protected AccessibleContext accessibleContext = null;

    
Gets the AccessibleContext associated with this Component. The method implemented by this base class returns null. Classes that extend Component should implement this method to return the AccessibleContext associated with the subclass. 
Returns:the AccessibleContext of this Component
Since:1.3
/**
     * Gets the {@code AccessibleContext} associated
     * with this {@code Component}.
     * The method implemented by this base
     * class returns null.  Classes that extend {@code Component}
     * should implement this method to return the
     * {@code AccessibleContext} associated with the subclass.
     *
     *
     * @return the {@code AccessibleContext} of this
     *    {@code Component}
     * @since 1.3
     */
    public AccessibleContext getAccessibleContext() {
        return accessibleContext;
    }

    
Inner class of Component used to provide default support for
accessibility.  This class is not meant to be used directly by
application developers, but is instead meant only to be
subclassed by component developers.


The class used to obtain the accessible role for this object.

Since:1.3
/**
     * Inner class of Component used to provide default support for
     * accessibility.  This class is not meant to be used directly by
     * application developers, but is instead meant only to be
     * subclassed by component developers.
     * <p>
     * The class used to obtain the accessible role for this object.
     * @since 1.3
     */
    protected abstract class AccessibleAWTComponent extends AccessibleContext
        implements Serializable, AccessibleComponent {

        private static final long serialVersionUID = 642321655757800191L;

        
Though the class is abstract, this should be called by
all sub-classes.

/**
         * Though the class is abstract, this should be called by
         * all sub-classes.
         */
        protected AccessibleAWTComponent() {
        }

        
Number of PropertyChangeListener objects registered. It's used
to add/remove ComponentListener and FocusListener to track
target Component's state.

/**
         * Number of PropertyChangeListener objects registered. It's used
         * to add/remove ComponentListener and FocusListener to track
         * target Component's state.
         */
        private transient volatile int propertyListenersCount = 0;

        
A component listener to track show/hide/resize events
and convert them to PropertyChange events.

/**
         * A component listener to track show/hide/resize events
         * and convert them to PropertyChange events.
         */
        protected ComponentListener accessibleAWTComponentHandler = null;

        
A listener to track focus events
and convert them to PropertyChange events.

/**
         * A listener to track focus events
         * and convert them to PropertyChange events.
         */
        protected FocusListener accessibleAWTFocusHandler = null;

        
Fire PropertyChange listener, if one is registered,
when shown/hidden..

Since:1.3
/**
         * Fire PropertyChange listener, if one is registered,
         * when shown/hidden..
         * @since 1.3
         */
        protected class AccessibleAWTComponentHandler implements ComponentListener, Serializable {
            private static final long serialVersionUID = -1009684107426231869L;

            public void componentHidden(ComponentEvent e)  {
                if (accessibleContext != null) {
                    accessibleContext.firePropertyChange(
                                                         AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                         AccessibleState.VISIBLE, null);
                }
            }

            public void componentShown(ComponentEvent e)  {
                if (accessibleContext != null) {
                    accessibleContext.firePropertyChange(
                                                         AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                         null, AccessibleState.VISIBLE);
                }
            }

            public void componentMoved(ComponentEvent e)  {
            }

            public void componentResized(ComponentEvent e)  {
            }
        } // inner class AccessibleAWTComponentHandler


        
Fire PropertyChange listener, if one is registered,
when focus events happen

Since:1.3
/**
         * Fire PropertyChange listener, if one is registered,
         * when focus events happen
         * @since 1.3
         */
        protected class AccessibleAWTFocusHandler implements FocusListener, Serializable {
            private static final long serialVersionUID = 3150908257351582233L;

            public void focusGained(FocusEvent event) {
                if (accessibleContext != null) {
                    accessibleContext.firePropertyChange(
                                                         AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                         null, AccessibleState.FOCUSED);
                }
            }
            public void focusLost(FocusEvent event) {
                if (accessibleContext != null) {
                    accessibleContext.firePropertyChange(
                                                         AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                         AccessibleState.FOCUSED, null);
                }
            }
        }  // inner class AccessibleAWTFocusHandler


        
Adds a PropertyChangeListener to the listener list. 
Params:
  • listener –  the property change listener to be added
/**
         * Adds a {@code PropertyChangeListener} to the listener list.
         *
         * @param listener  the property change listener to be added
         */
        public void addPropertyChangeListener(PropertyChangeListener listener) {
            if (accessibleAWTComponentHandler == null) {
                accessibleAWTComponentHandler = new AccessibleAWTComponentHandler();
            }
            if (accessibleAWTFocusHandler == null) {
                accessibleAWTFocusHandler = new AccessibleAWTFocusHandler();
            }
            if (propertyListenersCount++ == 0) {
                Component.this.addComponentListener(accessibleAWTComponentHandler);
                Component.this.addFocusListener(accessibleAWTFocusHandler);
            }
            super.addPropertyChangeListener(listener);
        }

        
Remove a PropertyChangeListener from the listener list.
This removes a PropertyChangeListener that was registered
for all properties.

Params:
  • listener –  The PropertyChangeListener to be removed
/**
         * Remove a PropertyChangeListener from the listener list.
         * This removes a PropertyChangeListener that was registered
         * for all properties.
         *
         * @param listener  The PropertyChangeListener to be removed
         */
        public void removePropertyChangeListener(PropertyChangeListener listener) {
            if (--propertyListenersCount == 0) {
                Component.this.removeComponentListener(accessibleAWTComponentHandler);
                Component.this.removeFocusListener(accessibleAWTFocusHandler);
            }
            super.removePropertyChangeListener(listener);
        }

        // AccessibleContext methods
        //
        
Gets the accessible name of this object. This should almost never return java.awt.Component.getName(), as that generally isn't a localized name, and doesn't have meaning for the user. If the object is fundamentally a text object (e.g. a menu item), the accessible name should be the text of the object (e.g. "save"). If the object has a tooltip, the tooltip text may also be an appropriate String to return. 
See Also:
Returns:the localized name of the object -- can be null if this object does not have a name
/**
         * Gets the accessible name of this object.  This should almost never
         * return {@code java.awt.Component.getName()},
         * as that generally isn't a localized name,
         * and doesn't have meaning for the user.  If the
         * object is fundamentally a text object (e.g. a menu item), the
         * accessible name should be the text of the object (e.g. "save").
         * If the object has a tooltip, the tooltip text may also be an
         * appropriate String to return.
         *
         * @return the localized name of the object -- can be
         *         {@code null} if this
         *         object does not have a name
         * @see javax.accessibility.AccessibleContext#setAccessibleName
         */
        public String getAccessibleName() {
            return accessibleName;
        }

        
Gets the accessible description of this object.  This should be
a concise, localized description of what this object is - what
is its meaning to the user.  If the object has a tooltip, the
tooltip text may be an appropriate string to return, assuming
it contains a concise description of the object (instead of just
the name of the object - e.g. a "Save" icon on a toolbar that
had "save" as the tooltip text shouldn't return the tooltip
text as the description, but something like "Saves the current
text document" instead).

See Also:
Returns:the localized description of the object -- can be null if this object does not have a description
/**
         * Gets the accessible description of this object.  This should be
         * a concise, localized description of what this object is - what
         * is its meaning to the user.  If the object has a tooltip, the
         * tooltip text may be an appropriate string to return, assuming
         * it contains a concise description of the object (instead of just
         * the name of the object - e.g. a "Save" icon on a toolbar that
         * had "save" as the tooltip text shouldn't return the tooltip
         * text as the description, but something like "Saves the current
         * text document" instead).
         *
         * @return the localized description of the object -- can be
         *        {@code null} if this object does not have a description
         * @see javax.accessibility.AccessibleContext#setAccessibleDescription
         */
        public String getAccessibleDescription() {
            return accessibleDescription;
        }

        
Gets the role of this object.

See Also:
Returns:an instance of AccessibleRole describing the role of the object
/**
         * Gets the role of this object.
         *
         * @return an instance of {@code AccessibleRole}
         *      describing the role of the object
         * @see javax.accessibility.AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.AWT_COMPONENT;
        }

        
Gets the state of this object.

See Also:
Returns:an instance of AccessibleStateSet containing the current state set of the object
/**
         * Gets the state of this object.
         *
         * @return an instance of {@code AccessibleStateSet}
         *       containing the current state set of the object
         * @see javax.accessibility.AccessibleState
         */
        public AccessibleStateSet getAccessibleStateSet() {
            return Component.this.getAccessibleStateSet();
        }

        
Gets the Accessible parent of this object. If the parent of this object implements Accessible, this method should simply return getParent. 
Returns:the Accessible parent of this object -- can be null if this object does not have an Accessible parent
/**
         * Gets the {@code Accessible} parent of this object.
         * If the parent of this object implements {@code Accessible},
         * this method should simply return {@code getParent}.
         *
         * @return the {@code Accessible} parent of this
         *      object -- can be {@code null} if this
         *      object does not have an {@code Accessible} parent
         */
        public Accessible getAccessibleParent() {
            if (accessibleParent != null) {
                return accessibleParent;
            } else {
                Container parent = getParent();
                if (parent instanceof Accessible) {
                    return (Accessible) parent;
                }
            }
            return null;
        }

        
Gets the index of this object in its accessible parent.

See Also:
Returns:the index of this object in its parent; or -1 if this
   object does not have an accessible parent
/**
         * Gets the index of this object in its accessible parent.
         *
         * @return the index of this object in its parent; or -1 if this
         *    object does not have an accessible parent
         * @see #getAccessibleParent
         */
        public int getAccessibleIndexInParent() {
            return Component.this.getAccessibleIndexInParent();
        }

        
Returns the number of accessible children in the object. If all of the children of this object implement Accessible, then this method should return the number of children of this object. 
Returns:the number of accessible children in the object
/**
         * Returns the number of accessible children in the object.  If all
         * of the children of this object implement {@code Accessible},
         * then this method should return the number of children of this object.
         *
         * @return the number of accessible children in the object
         */
        public int getAccessibleChildrenCount() {
            return 0; // Components don't have children
        }

        
Returns the nth Accessible child of the object. 
Params:
  • i – zero-based index of child
Returns:the nth Accessible child of the object
/**
         * Returns the nth {@code Accessible} child of the object.
         *
         * @param i zero-based index of child
         * @return the nth {@code Accessible} child of the object
         */
        public Accessible getAccessibleChild(int i) {
            return null; // Components don't have children
        }

        
Returns the locale of this object.

Returns:the locale of this object
/**
         * Returns the locale of this object.
         *
         * @return the locale of this object
         */
        public Locale getLocale() {
            return Component.this.getLocale();
        }

        
Gets the AccessibleComponent associated with this object if one exists. Otherwise return null. 
Returns:the component
/**
         * Gets the {@code AccessibleComponent} associated
         * with this object if one exists.
         * Otherwise return {@code null}.
         *
         * @return the component
         */
        public AccessibleComponent getAccessibleComponent() {
            return this;
        }


        // AccessibleComponent methods
        //
        
Gets the background color of this object.

Returns:the background color, if supported, of the object; otherwise, null
/**
         * Gets the background color of this object.
         *
         * @return the background color, if supported, of the object;
         *      otherwise, {@code null}
         */
        public Color getBackground() {
            return Component.this.getBackground();
        }

        
Sets the background color of this object. (For transparency, see isOpaque.) 
Params:
  • c – the new Color for the background
See Also:
/**
         * Sets the background color of this object.
         * (For transparency, see {@code isOpaque}.)
         *
         * @param c the new {@code Color} for the background
         * @see Component#isOpaque
         */
        public void setBackground(Color c) {
            Component.this.setBackground(c);
        }

        
Gets the foreground color of this object.

Returns:the foreground color, if supported, of the object; otherwise, null
/**
         * Gets the foreground color of this object.
         *
         * @return the foreground color, if supported, of the object;
         *     otherwise, {@code null}
         */
        public Color getForeground() {
            return Component.this.getForeground();
        }

        
Sets the foreground color of this object.

Params:
  • c – the new Color for the foreground
/**
         * Sets the foreground color of this object.
         *
         * @param c the new {@code Color} for the foreground
         */
        public void setForeground(Color c) {
            Component.this.setForeground(c);
        }

        
Gets the Cursor of this object. 
Returns:the Cursor, if supported, of the object; otherwise, null
/**
         * Gets the {@code Cursor} of this object.
         *
         * @return the {@code Cursor}, if supported,
         *     of the object; otherwise, {@code null}
         */
        public Cursor getCursor() {
            return Component.this.getCursor();
        }

        
Sets the Cursor of this object. 

The method may have no visual effect if the Java platform
implementation and/or the native system do not support
changing the mouse cursor shape.

Params:
  • cursor – the new Cursor for the object
/**
         * Sets the {@code Cursor} of this object.
         * <p>
         * The method may have no visual effect if the Java platform
         * implementation and/or the native system do not support
         * changing the mouse cursor shape.
         * @param cursor the new {@code Cursor} for the object
         */
        public void setCursor(Cursor cursor) {
            Component.this.setCursor(cursor);
        }

        
Gets the Font of this object. 
Returns:the Font, if supported, for the object; otherwise, null
/**
         * Gets the {@code Font} of this object.
         *
         * @return the {@code Font}, if supported,
         *    for the object; otherwise, {@code null}
         */
        public Font getFont() {
            return Component.this.getFont();
        }

        
Sets the Font of this object. 
Params:
  • f – the new Font for the object
/**
         * Sets the {@code Font} of this object.
         *
         * @param f the new {@code Font} for the object
         */
        public void setFont(Font f) {
            Component.this.setFont(f);
        }

        
Gets the FontMetrics of this object. 
Params:
  • f – the Font
See Also:
Returns:the FontMetrics, if supported, the object; otherwise, null
/**
         * Gets the {@code FontMetrics} of this object.
         *
         * @param f the {@code Font}
         * @return the {@code FontMetrics}, if supported,
         *     the object; otherwise, {@code null}
         * @see #getFont
         */
        public FontMetrics getFontMetrics(Font f) {
            if (f == null) {
                return null;
            } else {
                return Component.this.getFontMetrics(f);
            }
        }

        
Determines if the object is enabled.

Returns:true if object is enabled; otherwise, false
/**
         * Determines if the object is enabled.
         *
         * @return true if object is enabled; otherwise, false
         */
        public boolean isEnabled() {
            return Component.this.isEnabled();
        }

        
Sets the enabled state of the object.

Params:
  • b – if true, enables this object; otherwise, disables it
/**
         * Sets the enabled state of the object.
         *
         * @param b if true, enables this object; otherwise, disables it
         */
        public void setEnabled(boolean b) {
            boolean old = Component.this.isEnabled();
            Component.this.setEnabled(b);
            if (b != old) {
                if (accessibleContext != null) {
                    if (b) {
                        accessibleContext.firePropertyChange(
                                                             AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                             null, AccessibleState.ENABLED);
                    } else {
                        accessibleContext.firePropertyChange(
                                                             AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                             AccessibleState.ENABLED, null);
                    }
                }
            }
        }

        
Determines if the object is visible. Note: this means that the object intends to be visible; however, it may not in fact be showing on the screen because one of the objects that this object is contained by is not visible. To determine if an object is showing on the screen, use isShowing. 
Returns:true if object is visible; otherwise, false
/**
         * Determines if the object is visible.  Note: this means that the
         * object intends to be visible; however, it may not in fact be
         * showing on the screen because one of the objects that this object
         * is contained by is not visible.  To determine if an object is
         * showing on the screen, use {@code isShowing}.
         *
         * @return true if object is visible; otherwise, false
         */
        public boolean isVisible() {
            return Component.this.isVisible();
        }

        
Sets the visible state of the object.

Params:
  • b – if true, shows this object; otherwise, hides it
/**
         * Sets the visible state of the object.
         *
         * @param b if true, shows this object; otherwise, hides it
         */
        public void setVisible(boolean b) {
            boolean old = Component.this.isVisible();
            Component.this.setVisible(b);
            if (b != old) {
                if (accessibleContext != null) {
                    if (b) {
                        accessibleContext.firePropertyChange(
                                                             AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                             null, AccessibleState.VISIBLE);
                    } else {
                        accessibleContext.firePropertyChange(
                                                             AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                                                             AccessibleState.VISIBLE, null);
                    }
                }
            }
        }

        
Determines if the object is showing.  This is determined by checking
the visibility of the object and ancestors of the object.  Note:
this will return true even if the object is obscured by another
(for example, it happens to be underneath a menu that was pulled
down).

Returns:true if object is showing; otherwise, false
/**
         * Determines if the object is showing.  This is determined by checking
         * the visibility of the object and ancestors of the object.  Note:
         * this will return true even if the object is obscured by another
         * (for example, it happens to be underneath a menu that was pulled
         * down).
         *
         * @return true if object is showing; otherwise, false
         */
        public boolean isShowing() {
            return Component.this.isShowing();
        }

        
Checks whether the specified point is within this object's bounds,
where the point's x and y coordinates are defined to be relative to
the coordinate system of the object.

Params:
  • p – the Point relative to the coordinate system of the object
Returns:true if object contains Point; otherwise false
/**
         * Checks whether the specified point is within this object's bounds,
         * where the point's x and y coordinates are defined to be relative to
         * the coordinate system of the object.
         *
         * @param p the {@code Point} relative to the
         *     coordinate system of the object
         * @return true if object contains {@code Point}; otherwise false
         */
        public boolean contains(Point p) {
            return Component.this.contains(p);
        }

        
Returns the location of the object on the screen.

Returns:location of object on screen -- can be null if this object is not on the screen
/**
         * Returns the location of the object on the screen.
         *
         * @return location of object on screen -- can be
         *    {@code null} if this object is not on the screen
         */
        public Point getLocationOnScreen() {
            synchronized (Component.this.getTreeLock()) {
                if (Component.this.isShowing()) {
                    return Component.this.getLocationOnScreen();
                } else {
                    return null;
                }
            }
        }

        
Gets the location of the object relative to the parent in the form
of a point specifying the object's top-left corner in the screen's
coordinate space.

Returns:an instance of Point representing the top-left corner of the object's bounds in the coordinate space of the screen; null if this object or its parent are not on the screen
/**
         * Gets the location of the object relative to the parent in the form
         * of a point specifying the object's top-left corner in the screen's
         * coordinate space.
         *
         * @return an instance of Point representing the top-left corner of
         * the object's bounds in the coordinate space of the screen;
         * {@code null} if this object or its parent are not on the screen
         */
        public Point getLocation() {
            return Component.this.getLocation();
        }

        
Sets the location of the object relative to the parent.

Params:
  • p –  the coordinates of the object
/**
         * Sets the location of the object relative to the parent.
         * @param p  the coordinates of the object
         */
        public void setLocation(Point p) {
            Component.this.setLocation(p);
        }

        
Gets the bounds of this object in the form of a Rectangle object.
The bounds specify this object's width, height, and location
relative to its parent.

Returns:a rectangle indicating this component's bounds; null if this object is not on the screen
/**
         * Gets the bounds of this object in the form of a Rectangle object.
         * The bounds specify this object's width, height, and location
         * relative to its parent.
         *
         * @return a rectangle indicating this component's bounds;
         *   {@code null} if this object is not on the screen
         */
        public Rectangle getBounds() {
            return Component.this.getBounds();
        }

        
Sets the bounds of this object in the form of a Rectangle object. The bounds specify this object's width, height, and location relative to its parent. 
Params:
  • r – a rectangle indicating this component's bounds
/**
         * Sets the bounds of this object in the form of a
         * {@code Rectangle} object.
         * The bounds specify this object's width, height, and location
         * relative to its parent.
         *
         * @param r a rectangle indicating this component's bounds
         */
        public void setBounds(Rectangle r) {
            Component.this.setBounds(r);
        }

        
Returns the size of this object in the form of a Dimension object. The height field of the Dimension object contains this object's height, and the width field of the Dimension object contains this object's width. 
Returns:a Dimension object that indicates the size of this component; null if this object is not on the screen
/**
         * Returns the size of this object in the form of a
         * {@code Dimension} object. The height field of the
         * {@code Dimension} object contains this object's
         * height, and the width field of the {@code Dimension}
         * object contains this object's width.
         *
         * @return a {@code Dimension} object that indicates
         *     the size of this component; {@code null} if
         *     this object is not on the screen
         */
        public Dimension getSize() {
            return Component.this.getSize();
        }

        
Resizes this object so that it has width and height.

Params:
  • d – the dimension specifying the new size of the object
/**
         * Resizes this object so that it has width and height.
         *
         * @param d the dimension specifying the new size of the object
         */
        public void setSize(Dimension d) {
            Component.this.setSize(d);
        }

        
Returns the Accessible child, if one exists, contained at the local coordinate Point. Otherwise returns null. 
Params:
  • p – the point defining the top-left corner of the Accessible, given in the coordinate space of the object's parent
Returns:the Accessible, if it exists, at the specified location; else null
/**
         * Returns the {@code Accessible} child,
         * if one exists, contained at the local
         * coordinate {@code Point}.  Otherwise returns
         * {@code null}.
         *
         * @param p the point defining the top-left corner of
         *      the {@code Accessible}, given in the
         *      coordinate space of the object's parent
         * @return the {@code Accessible}, if it exists,
         *      at the specified location; else {@code null}
         */
        public Accessible getAccessibleAt(Point p) {
            return null; // Components don't have children
        }

        
Returns whether this object can accept focus or not.

Returns:true if object can accept focus; otherwise false
/**
         * Returns whether this object can accept focus or not.
         *
         * @return true if object can accept focus; otherwise false
         */
        public boolean isFocusTraversable() {
            return Component.this.isFocusTraversable();
        }

        
Requests focus for this object.

/**
         * Requests focus for this object.
         */
        public void requestFocus() {
            Component.this.requestFocus();
        }

        
Adds the specified focus listener to receive focus events from this
component.

Params:
  • l – the focus listener
/**
         * Adds the specified focus listener to receive focus events from this
         * component.
         *
         * @param l the focus listener
         */
        public void addFocusListener(FocusListener l) {
            Component.this.addFocusListener(l);
        }

        
Removes the specified focus listener so it no longer receives focus
events from this component.

Params:
  • l – the focus listener
/**
         * Removes the specified focus listener so it no longer receives focus
         * events from this component.
         *
         * @param l the focus listener
         */
        public void removeFocusListener(FocusListener l) {
            Component.this.removeFocusListener(l);
        }

    } // inner class AccessibleAWTComponent


    
Gets the index of this object in its accessible parent.
If this object does not have an accessible parent, returns
-1.

Returns:the index of this object in its accessible parent
/**
     * Gets the index of this object in its accessible parent.
     * If this object does not have an accessible parent, returns
     * -1.
     *
     * @return the index of this object in its accessible parent
     */
    int getAccessibleIndexInParent() {
        synchronized (getTreeLock()) {

            AccessibleContext accContext = getAccessibleContext();
            if (accContext == null) {
                return -1;
            }

            Accessible parent = accContext.getAccessibleParent();
            if (parent == null) {
                return -1;
            }

            accContext = parent.getAccessibleContext();
            for (int i = 0; i < accContext.getAccessibleChildrenCount(); i++) {
                if (this.equals(accContext.getAccessibleChild(i))) {
                    return i;
                }
            }

            return -1;
        }
    }

    
Gets the current state set of this object.

See Also:
Returns:an instance of AccessibleStateSet containing the current state set of the object
/**
     * Gets the current state set of this object.
     *
     * @return an instance of {@code AccessibleStateSet}
     *    containing the current state set of the object
     * @see AccessibleState
     */
    AccessibleStateSet getAccessibleStateSet() {
        synchronized (getTreeLock()) {
            AccessibleStateSet states = new AccessibleStateSet();
            if (this.isEnabled()) {
                states.add(AccessibleState.ENABLED);
            }
            if (this.isFocusTraversable()) {
                states.add(AccessibleState.FOCUSABLE);
            }
            if (this.isVisible()) {
                states.add(AccessibleState.VISIBLE);
            }
            if (this.isShowing()) {
                states.add(AccessibleState.SHOWING);
            }
            if (this.isFocusOwner()) {
                states.add(AccessibleState.FOCUSED);
            }
            if (this instanceof Accessible) {
                AccessibleContext ac = ((Accessible) this).getAccessibleContext();
                if (ac != null) {
                    Accessible ap = ac.getAccessibleParent();
                    if (ap != null) {
                        AccessibleContext pac = ap.getAccessibleContext();
                        if (pac != null) {
                            AccessibleSelection as = pac.getAccessibleSelection();
                            if (as != null) {
                                states.add(AccessibleState.SELECTABLE);
                                int i = ac.getAccessibleIndexInParent();
                                if (i >= 0) {
                                    if (as.isAccessibleChildSelected(i)) {
                                        states.add(AccessibleState.SELECTED);
                                    }
                                }
                            }
                        }
                    }
                }
            }
            if (Component.isInstanceOf(this, "javax.swing.JComponent")) {
                if (((javax.swing.JComponent) this).isOpaque()) {
                    states.add(AccessibleState.OPAQUE);
                }
            }
            return states;
        }
    }

    
Checks that the given object is instance of the given class.

Params:
  • obj – Object to be checked
  • className – The name of the class. Must be fully-qualified class name.
Returns:true, if this object is instanceof given class,
        false, otherwise, or if obj or className is null
/**
     * Checks that the given object is instance of the given class.
     * @param obj Object to be checked
     * @param className The name of the class. Must be fully-qualified class name.
     * @return true, if this object is instanceof given class,
     *         false, otherwise, or if obj or className is null
     */
    static boolean isInstanceOf(Object obj, String className) {
        if (obj == null) return false;
        if (className == null) return false;

        Class<?> cls = obj.getClass();
        while (cls != null) {
            if (cls.getName().equals(className)) {
                return true;
            }
            cls = cls.getSuperclass();
        }
        return false;
    }


    // ************************** MIXING CODE *******************************

    
Check whether we can trust the current bounds of the component.
The return value of false indicates that the container of the
component is invalid, and therefore needs to be laid out, which would
probably mean changing the bounds of its children.
Null-layout of the container or absence of the container mean
the bounds of the component are final and can be trusted.

/**
     * Check whether we can trust the current bounds of the component.
     * The return value of false indicates that the container of the
     * component is invalid, and therefore needs to be laid out, which would
     * probably mean changing the bounds of its children.
     * Null-layout of the container or absence of the container mean
     * the bounds of the component are final and can be trusted.
     */
    final boolean areBoundsValid() {
        Container cont = getContainer();
        return cont == null || cont.isValid() || cont.getLayout() == null;
    }

    
Applies the shape to the component

Params:
  • shape – Shape to be applied to the component
/**
     * Applies the shape to the component
     * @param shape Shape to be applied to the component
     */
    void applyCompoundShape(Region shape) {
        checkTreeLock();

        if (!areBoundsValid()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this + "; areBoundsValid = " + areBoundsValid());
            }
            return;
        }

        if (!isLightweight()) {
            ComponentPeer peer = this.peer;
            if (peer != null) {
                // The Region class has some optimizations. That's why
                // we should manually check whether it's empty and
                // substitute the object ourselves. Otherwise we end up
                // with some incorrect Region object with loX being
                // greater than the hiX for instance.
                if (shape.isEmpty()) {
                    shape = Region.EMPTY_REGION;
                }


                // Note: the shape is not really copied/cloned. We create
                // the Region object ourselves, so there's no any possibility
                // to modify the object outside of the mixing code.
                // Nullifying compoundShape means that the component has normal shape
                // (or has no shape at all).
                if (shape.equals(getNormalShape())) {
                    if (this.compoundShape == null) {
                        return;
                    }
                    this.compoundShape = null;
                    peer.applyShape(null);
                } else {
                    if (shape.equals(getAppliedShape())) {
                        return;
                    }
                    this.compoundShape = shape;
                    Point compAbsolute = getLocationOnWindow();
                    if (mixingLog.isLoggable(PlatformLogger.Level.FINER)) {
                        mixingLog.fine("this = " + this +
                                "; compAbsolute=" + compAbsolute + "; shape=" + shape);
                    }
                    peer.applyShape(shape.getTranslatedRegion(-compAbsolute.x, -compAbsolute.y));
                }
            }
        }
    }

    
Returns the shape previously set with applyCompoundShape().
If the component is LW or no shape was applied yet,
the method returns the normal shape.

/**
     * Returns the shape previously set with applyCompoundShape().
     * If the component is LW or no shape was applied yet,
     * the method returns the normal shape.
     */
    private Region getAppliedShape() {
        checkTreeLock();
        //XXX: if we allow LW components to have a shape, this must be changed
        return (this.compoundShape == null || isLightweight()) ? getNormalShape() : this.compoundShape;
    }

    Point getLocationOnWindow() {
        checkTreeLock();
        Point curLocation = getLocation();

        for (Container parent = getContainer();
                parent != null && !(parent instanceof Window);
                parent = parent.getContainer())
        {
            curLocation.x += parent.getX();
            curLocation.y += parent.getY();
        }

        return curLocation;
    }

    
Returns the full shape of the component located in window coordinates

/**
     * Returns the full shape of the component located in window coordinates
     */
    final Region getNormalShape() {
        checkTreeLock();
        //XXX: we may take into account a user-specified shape for this component
        Point compAbsolute = getLocationOnWindow();
        return
            Region.getInstanceXYWH(
                    compAbsolute.x,
                    compAbsolute.y,
                    getWidth(),
                    getHeight()
            );
    }

    
Returns the "opaque shape" of the component.
The opaque shape of a lightweight components is the actual shape that
needs to be cut off of the heavyweight components in order to mix this
lightweight component correctly with them.
The method is overriden in the java.awt.Container to handle non-opaque
containers containing opaque children.
See 6637655 for details.

/**
     * Returns the "opaque shape" of the component.
     *
     * The opaque shape of a lightweight components is the actual shape that
     * needs to be cut off of the heavyweight components in order to mix this
     * lightweight component correctly with them.
     *
     * The method is overriden in the java.awt.Container to handle non-opaque
     * containers containing opaque children.
     *
     * See 6637655 for details.
     */
    Region getOpaqueShape() {
        checkTreeLock();
        if (mixingCutoutRegion != null) {
            return mixingCutoutRegion;
        } else {
            return getNormalShape();
        }
    }

    final int getSiblingIndexAbove() {
        checkTreeLock();
        Container parent = getContainer();
        if (parent == null) {
            return -1;
        }

        int nextAbove = parent.getComponentZOrder(this) - 1;

        return nextAbove < 0 ? -1 : nextAbove;
    }

    final ComponentPeer getHWPeerAboveMe() {
        checkTreeLock();

        Container cont = getContainer();
        int indexAbove = getSiblingIndexAbove();

        while (cont != null) {
            for (int i = indexAbove; i > -1; i--) {
                Component comp = cont.getComponent(i);
                if (comp != null && comp.isDisplayable() && !comp.isLightweight()) {
                    return comp.peer;
                }
            }
            // traversing the hierarchy up to the closest HW container;
            // further traversing may return a component that is not actually
            // a native sibling of this component and this kind of z-order
            // request may not be allowed by the underlying system (6852051).
            if (!cont.isLightweight()) {
                break;
            }

            indexAbove = cont.getSiblingIndexAbove();
            cont = cont.getContainer();
        }

        return null;
    }

    final int getSiblingIndexBelow() {
        checkTreeLock();
        Container parent = getContainer();
        if (parent == null) {
            return -1;
        }

        int nextBelow = parent.getComponentZOrder(this) + 1;

        return nextBelow >= parent.getComponentCount() ? -1 : nextBelow;
    }

    final boolean isNonOpaqueForMixing() {
        return mixingCutoutRegion != null &&
            mixingCutoutRegion.isEmpty();
    }

    private Region calculateCurrentShape() {
        checkTreeLock();
        Region s = getNormalShape();

        if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
            mixingLog.fine("this = " + this + "; normalShape=" + s);
        }

        if (getContainer() != null) {
            Component comp = this;
            Container cont = comp.getContainer();

            while (cont != null) {
                for (int index = comp.getSiblingIndexAbove(); index != -1; --index) {
                    /* It is assumed that:
                     *
                     *    getComponent(getContainer().getComponentZOrder(comp)) == comp
                     *
                     * The assumption has been made according to the current
                     * implementation of the Container class.
                     */
                    Component c = cont.getComponent(index);
                    if (c.isLightweight() && c.isShowing()) {
                        s = s.getDifference(c.getOpaqueShape());
                    }
                }

                if (cont.isLightweight()) {
                    s = s.getIntersection(cont.getNormalShape());
                } else {
                    break;
                }

                comp = cont;
                cont = cont.getContainer();
            }
        }

        if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
            mixingLog.fine("currentShape=" + s);
        }

        return s;
    }

    void applyCurrentShape() {
        checkTreeLock();
        if (!areBoundsValid()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this + "; areBoundsValid = " + areBoundsValid());
            }
            return; // Because applyCompoundShape() ignores such components anyway
        }
        if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
            mixingLog.fine("this = " + this);
        }
        applyCompoundShape(calculateCurrentShape());
    }

    final void subtractAndApplyShape(Region s) {
        checkTreeLock();

        if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
            mixingLog.fine("this = " + this + "; s=" + s);
        }

        applyCompoundShape(getAppliedShape().getDifference(s));
    }

    private void applyCurrentShapeBelowMe() {
        checkTreeLock();
        Container parent = getContainer();
        if (parent != null && parent.isShowing()) {
            // First, reapply shapes of my siblings
            parent.recursiveApplyCurrentShape(getSiblingIndexBelow());

            // Second, if my container is non-opaque, reapply shapes of siblings of my container
            Container parent2 = parent.getContainer();
            while (!parent.isOpaque() && parent2 != null) {
                parent2.recursiveApplyCurrentShape(parent.getSiblingIndexBelow());

                parent = parent2;
                parent2 = parent.getContainer();
            }
        }
    }

    final void subtractAndApplyShapeBelowMe() {
        checkTreeLock();
        Container parent = getContainer();
        if (parent != null && isShowing()) {
            Region opaqueShape = getOpaqueShape();

            // First, cut my siblings
            parent.recursiveSubtractAndApplyShape(opaqueShape, getSiblingIndexBelow());

            // Second, if my container is non-opaque, cut siblings of my container
            Container parent2 = parent.getContainer();
            while (!parent.isOpaque() && parent2 != null) {
                parent2.recursiveSubtractAndApplyShape(opaqueShape, parent.getSiblingIndexBelow());

                parent = parent2;
                parent2 = parent.getContainer();
            }
        }
    }

    void mixOnShowing() {
        synchronized (getTreeLock()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this);
            }
            if (!isMixingNeeded()) {
                return;
            }
            if (isLightweight()) {
                subtractAndApplyShapeBelowMe();
            } else {
                applyCurrentShape();
            }
        }
    }

    void mixOnHiding(boolean isLightweight) {
        // We cannot be sure that the peer exists at this point, so we need the argument
        //    to find out whether the hiding component is (well, actually was) a LW or a HW.
        synchronized (getTreeLock()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this + "; isLightweight = " + isLightweight);
            }
            if (!isMixingNeeded()) {
                return;
            }
            if (isLightweight) {
                applyCurrentShapeBelowMe();
            }
        }
    }

    void mixOnReshaping() {
        synchronized (getTreeLock()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this);
            }
            if (!isMixingNeeded()) {
                return;
            }
            if (isLightweight()) {
                applyCurrentShapeBelowMe();
            } else {
                applyCurrentShape();
            }
        }
    }

    void mixOnZOrderChanging(int oldZorder, int newZorder) {
        synchronized (getTreeLock()) {
            boolean becameHigher = newZorder < oldZorder;
            Container parent = getContainer();

            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this +
                    "; oldZorder=" + oldZorder + "; newZorder=" + newZorder + "; parent=" + parent);
            }
            if (!isMixingNeeded()) {
                return;
            }
            if (isLightweight()) {
                if (becameHigher) {
                    if (parent != null && isShowing()) {
                        parent.recursiveSubtractAndApplyShape(getOpaqueShape(), getSiblingIndexBelow(), oldZorder);
                    }
                } else {
                    if (parent != null) {
                        parent.recursiveApplyCurrentShape(oldZorder, newZorder);
                    }
                }
            } else {
                if (becameHigher) {
                    applyCurrentShape();
                } else {
                    if (parent != null) {
                        Region shape = getAppliedShape();

                        for (int index = oldZorder; index < newZorder; index++) {
                            Component c = parent.getComponent(index);
                            if (c.isLightweight() && c.isShowing()) {
                                shape = shape.getDifference(c.getOpaqueShape());
                            }
                        }
                        applyCompoundShape(shape);
                    }
                }
            }
        }
    }

    void mixOnValidating() {
        // This method gets overriden in the Container. Obviously, a plain
        // non-container components don't need to handle validation.
    }

    final boolean isMixingNeeded() {
        if (SunToolkit.getSunAwtDisableMixing()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINEST)) {
                mixingLog.finest("this = " + this + "; Mixing disabled via sun.awt.disableMixing");
            }
            return false;
        }
        if (!areBoundsValid()) {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this + "; areBoundsValid = " + areBoundsValid());
            }
            return false;
        }
        Window window = getContainingWindow();
        if (window != null) {
            if (!window.hasHeavyweightDescendants() || !window.hasLightweightDescendants() || window.isDisposing()) {
                if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                    mixingLog.fine("containing window = " + window +
                            "; has h/w descendants = " + window.hasHeavyweightDescendants() +
                            "; has l/w descendants = " + window.hasLightweightDescendants() +
                            "; disposing = " + window.isDisposing());
                }
                return false;
            }
        } else {
            if (mixingLog.isLoggable(PlatformLogger.Level.FINE)) {
                mixingLog.fine("this = " + this + "; containing window is null");
            }
            return false;
        }
        return true;
    }

    
Sets a 'mixing-cutout' shape for this lightweight component.
This method is used exclusively for the purposes of the
Heavyweight/Lightweight Components Mixing feature and will
have no effect if applied to a heavyweight component.
By default a lightweight component is treated as an opaque rectangle for
the purposes of the Heavyweight/Lightweight Components Mixing feature.
This method enables developers to set an arbitrary shape to be cut out
from heavyweight components positioned underneath the lightweight
component in the z-order.

 The shape argument may have the following values: 
    

  • null - reverts the default cutout shape (the rectangle equal to the component's getBounds()) 
  • empty-shape - does not cut out anything from heavyweight
components. This makes this lightweight component effectively
transparent. Note that descendants of the lightweight component still
affect the shapes of heavyweight components.  An example of an
empty-shape is new Rectangle(). 
  • non-empty-shape - the given shape will be cut out from
heavyweight components.



 The most common example when the 'mixing-cutout' shape is needed is a glass pane component. The JRootPane.setGlassPane method automatically sets the empty-shape as the 'mixing-cutout' shape
for the given glass pane component.  If a developer needs some other
'mixing-cutout' shape for the glass pane (which is rare), this must be
changed manually after installing the glass pane to the root pane.

Params:
  • shape – the new 'mixing-cutout' shape
Since:9
/**
     * Sets a 'mixing-cutout' shape for this lightweight component.
     *
     * This method is used exclusively for the purposes of the
     * Heavyweight/Lightweight Components Mixing feature and will
     * have no effect if applied to a heavyweight component.
     *
     * By default a lightweight component is treated as an opaque rectangle for
     * the purposes of the Heavyweight/Lightweight Components Mixing feature.
     * This method enables developers to set an arbitrary shape to be cut out
     * from heavyweight components positioned underneath the lightweight
     * component in the z-order.
     * <p>
     * The {@code shape} argument may have the following values:
     * <ul>
     * <li>{@code null} - reverts the default cutout shape (the rectangle equal
     * to the component's {@code getBounds()})
     * <li><i>empty-shape</i> - does not cut out anything from heavyweight
     * components. This makes this lightweight component effectively
     * transparent. Note that descendants of the lightweight component still
     * affect the shapes of heavyweight components.  An example of an
     * <i>empty-shape</i> is {@code new Rectangle()}.
     * <li><i>non-empty-shape</i> - the given shape will be cut out from
     * heavyweight components.
     * </ul>
     * <p>
     * The most common example when the 'mixing-cutout' shape is needed is a
     * glass pane component. The {@link JRootPane#setGlassPane} method
     * automatically sets the <i>empty-shape</i> as the 'mixing-cutout' shape
     * for the given glass pane component.  If a developer needs some other
     * 'mixing-cutout' shape for the glass pane (which is rare), this must be
     * changed manually after installing the glass pane to the root pane.
     *
     * @param shape the new 'mixing-cutout' shape
     * @since 9
     */
    public void setMixingCutoutShape(Shape shape) {
        Region region = shape == null ? null : Region.getInstance(shape, null);

        synchronized (getTreeLock()) {
            boolean needShowing = false;
            boolean needHiding = false;

            if (!isNonOpaqueForMixing()) {
                needHiding = true;
            }

            mixingCutoutRegion = region;

            if (!isNonOpaqueForMixing()) {
                needShowing = true;
            }

            if (isMixingNeeded()) {
                if (needHiding) {
                    mixOnHiding(isLightweight());
                }
                if (needShowing) {
                    mixOnShowing();
                }
            }
        }
    }

    // ****************** END OF MIXING CODE ********************************

    // Note that the method is overriden in the Window class,
    // a window doesn't need to be updated in the Z-order.
    void updateZOrder() {
        peer.setZOrder(getHWPeerAboveMe());
    }

}