https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2018, 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 javax.swing;


import java.beans.*;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Vector;
import java.util.EventListener;
import java.util.Set;

import java.awt.*;
import java.awt.event.*;

import java.applet.Applet;

import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.io.ObjectInputValidation;
import java.io.InvalidObjectException;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
import static javax.swing.ClientPropertyKey.*;
import javax.accessibility.*;

import sun.awt.AWTAccessor;
import sun.awt.SunToolkit;
import sun.swing.SwingAccessor;
import sun.swing.SwingUtilities2;


The base class for all Swing components except top-level containers.
To use a component that inherits from JComponent,
you must place the component in a containment hierarchy
whose root is a top-level Swing container.
Top-level Swing containers --
such as JFrame, JDialog,
and JApplet --
are specialized components
that provide a place for other Swing components to paint themselves.
For an explanation of containment hierarchies, see
Swing Components and the Containment Hierarchy,
a section in The Java Tutorial.


The JComponent class provides:

    

  • The base class for both standard and custom components
    that use the Swing architecture.

  • A "pluggable look and feel" (L&F) that can be specified by the
    programmer or (optionally) selected by the user at runtime.
    The look and feel for each component is provided by a
    UI delegate -- an object that descends from ComponentUI. See How
    to Set the Look and Feel
    in The Java Tutorial
    for more information.

  • Comprehensive keystroke handling.
    See the document How to Use Key Bindings,
    an article in The Java Tutorial,
    for more information.

  • Support for tool tips --
    short descriptions that pop up when the cursor lingers
    over a component.
    See How
    to Use Tool Tips
    in The Java Tutorial
    for more information.

  • Support for accessibility.
    JComponent contains all of the methods in the
    Accessible interface,
    but it doesn't actually implement the interface.  That is the
    responsibility of the individual classes
    that extend JComponent.

  • Support for component-specific properties. With the putClientProperty and getClientProperty methods, you can associate name-object pairs with any object that descends from JComponent.

  • An infrastructure for painting
    that includes double buffering and support for borders.
    For more information see Painting and
How
    to Use Borders,
    both of which are sections in The Java Tutorial.

 For more information on these subjects, see the Swing package description and The Java Tutorial section
The JComponent Class.


JComponent and its subclasses document default values
for certain properties.  For example, JTable documents the
default row height as 16.  Each JComponent subclass
that has a ComponentUI will create the
ComponentUI as part of its constructor.  In order
to provide a particular look and feel each
ComponentUI may set properties back on the
JComponent that created it.  For example, a custom
look and feel may require JTables to have a row
height of 24. The documented defaults are the value of a property
BEFORE the ComponentUI has been installed.  If you
need a specific value for a particular property you should
explicitly set it.


In release 1.4, the focus subsystem was rearchitected.
For more information, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.


Warning: Swing is not thread safe. For more
information see Swing's Threading
Policy.


Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:Hans Muller, Arnaud Weber
See Also:
Since:1.2
/**
 * The base class for all Swing components except top-level containers.
 * To use a component that inherits from <code>JComponent</code>,
 * you must place the component in a containment hierarchy
 * whose root is a top-level Swing container.
 * Top-level Swing containers --
 * such as <code>JFrame</code>, <code>JDialog</code>,
 * and <code>JApplet</code> --
 * are specialized components
 * that provide a place for other Swing components to paint themselves.
 * For an explanation of containment hierarchies, see
 * <a
 href="https://docs.oracle.com/javase/tutorial/uiswing/components/toplevel.html">Swing Components and the Containment Hierarchy</a>,
 * a section in <em>The Java Tutorial</em>.
 *
 * <p>
 * The <code>JComponent</code> class provides:
 * <ul>
 * <li>The base class for both standard and custom components
 *     that use the Swing architecture.
 * <li>A "pluggable look and feel" (L&amp;F) that can be specified by the
 *     programmer or (optionally) selected by the user at runtime.
 *     The look and feel for each component is provided by a
 *     <em>UI delegate</em> -- an object that descends from
 *     {@link javax.swing.plaf.ComponentUI}.
 *     See <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html">How
 *     to Set the Look and Feel</a>
 *     in <em>The Java Tutorial</em>
 *     for more information.
 * <li>Comprehensive keystroke handling.
 *     See the document <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/misc/keybinding.html">How to Use Key Bindings</a>,
 *     an article in <em>The Java Tutorial</em>,
 *     for more information.
 * <li>Support for tool tips --
 *     short descriptions that pop up when the cursor lingers
 *     over a component.
 *     See <a
 * href="https://docs.oracle.com/javase/tutorial/uiswing/components/tooltip.html">How
 *     to Use Tool Tips</a>
 *     in <em>The Java Tutorial</em>
 *     for more information.
 * <li>Support for accessibility.
 *     <code>JComponent</code> contains all of the methods in the
 *     <code>Accessible</code> interface,
 *     but it doesn't actually implement the interface.  That is the
 *     responsibility of the individual classes
 *     that extend <code>JComponent</code>.
 * <li>Support for component-specific properties.
 *     With the {@link #putClientProperty}
 *     and {@link #getClientProperty} methods,
 *     you can associate name-object pairs
 *     with any object that descends from <code>JComponent</code>.
 * <li>An infrastructure for painting
 *     that includes double buffering and support for borders.
 *     For more information see <a
 * href="http://www.oracle.com/technetwork/java/painting-140037.html#swing">Painting</a> and
 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/border.html">How
 *     to Use Borders</a>,
 *     both of which are sections in <em>The Java Tutorial</em>.
 * </ul>
 * For more information on these subjects, see the
 * {@link javax.swing Swing package description}
 * and <em>The Java Tutorial</em> section
 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/jcomponent.html">The JComponent Class</a>.
 * <p>
 * <code>JComponent</code> and its subclasses document default values
 * for certain properties.  For example, <code>JTable</code> documents the
 * default row height as 16.  Each <code>JComponent</code> subclass
 * that has a <code>ComponentUI</code> will create the
 * <code>ComponentUI</code> as part of its constructor.  In order
 * to provide a particular look and feel each
 * <code>ComponentUI</code> may set properties back on the
 * <code>JComponent</code> that created it.  For example, a custom
 * look and feel may require <code>JTable</code>s to have a row
 * height of 24. The documented defaults are the value of a property
 * BEFORE the <code>ComponentUI</code> has been installed.  If you
 * need a specific value for a particular property you should
 * explicitly set it.
 * <p>
 * In release 1.4, the focus subsystem was rearchitected.
 * For more information, see
 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
 * How to Use the Focus Subsystem</a>,
 * a section in <em>The Java Tutorial</em>.
 * <p>
 * <strong>Warning:</strong> Swing is not thread safe. For more
 * information see <a
 * href="package-summary.html#threading">Swing's Threading
 * Policy</a>.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @see KeyStroke
 * @see Action
 * @see #setBorder
 * @see #registerKeyboardAction
 * @see JOptionPane
 * @see #setDebugGraphicsOptions
 * @see #setToolTipText
 * @see #setAutoscrolls
 *
 * @author Hans Muller
 * @author Arnaud Weber
 * @since 1.2
 */
@JavaBean(defaultProperty = "UIClassID")
@SuppressWarnings("serial") // Same-version serialization only
public abstract class JComponent extends Container implements Serializable,
                                              TransferHandler.HasGetTransferHandler
{
    
See Also:
/**
     * @see #getUIClassID
     * @see #writeObject
     */
    private static final String uiClassID = "ComponentUI";

    
See Also:
  • readObject
/**
     * @see #readObject
     */
    private static final Hashtable<ObjectInputStream, ReadObjectCallback> readObjectCallbacks =
            new Hashtable<ObjectInputStream, ReadObjectCallback>(1);

    
Keys to use for forward focus traversal when the JComponent is
managing focus.

/**
     * Keys to use for forward focus traversal when the JComponent is
     * managing focus.
     */
    private static Set<KeyStroke> managingFocusForwardTraversalKeys;

    
Keys to use for backward focus traversal when the JComponent is
managing focus.

/**
     * Keys to use for backward focus traversal when the JComponent is
     * managing focus.
     */
    private static Set<KeyStroke> managingFocusBackwardTraversalKeys;

    // Following are the possible return values from getObscuredState.
    private static final int NOT_OBSCURED = 0;
    private static final int PARTIALLY_OBSCURED = 1;
    private static final int COMPLETELY_OBSCURED = 2;

    
Set to true when DebugGraphics has been loaded.

/**
     * Set to true when DebugGraphics has been loaded.
     */
    static boolean DEBUG_GRAPHICS_LOADED;

    
Key used to look up a value from the AppContext to determine the
JComponent the InputVerifier is running for. That is, if
AppContext.get(INPUT_VERIFIER_SOURCE_KEY) returns non-null, it
indicates the EDT is calling into the InputVerifier from the
returned component.

/**
     * Key used to look up a value from the AppContext to determine the
     * JComponent the InputVerifier is running for. That is, if
     * AppContext.get(INPUT_VERIFIER_SOURCE_KEY) returns non-null, it
     * indicates the EDT is calling into the InputVerifier from the
     * returned component.
     */
    private static final Object INPUT_VERIFIER_SOURCE_KEY =
            new StringBuilder("InputVerifierSourceKey");

    /* The following fields support set methods for the corresponding
     * java.awt.Component properties.
     */
    private boolean isAlignmentXSet;
    private float alignmentX;
    private boolean isAlignmentYSet;
    private float alignmentY;

    /**
     * Backing store for JComponent properties and listeners
     */

    
The look and feel delegate for this component. 
/** The look and feel delegate for this component. */
    protected transient ComponentUI ui;
    
A list of event listeners for this component. 
/** A list of event listeners for this component. */
    protected EventListenerList listenerList = new EventListenerList();

    private transient ArrayTable clientProperties;
    private VetoableChangeSupport vetoableChangeSupport;
    
Whether or not autoscroll has been enabled.

/**
     * Whether or not autoscroll has been enabled.
     */
    private boolean autoscrolls;
    private Border border;
    private int flags;

    /* Input verifier for this component */
    private InputVerifier inputVerifier = null;

    private boolean verifyInputWhenFocusTarget = true;

    
Set in _paintImmediately.
Will indicate the child that initiated the painting operation.
If paintingChild is opaque, no need to paint
any child components after paintingChild.
Test used in paintChildren.

/**
     * Set in <code>_paintImmediately</code>.
     * Will indicate the child that initiated the painting operation.
     * If <code>paintingChild</code> is opaque, no need to paint
     * any child components after <code>paintingChild</code>.
     * Test used in <code>paintChildren</code>.
     */
    transient Component         paintingChild;

    
Constant used for registerKeyboardAction that
means that the command should be invoked when
the component has the focus.

/**
     * Constant used for <code>registerKeyboardAction</code> that
     * means that the command should be invoked when
     * the component has the focus.
     */
    public static final int WHEN_FOCUSED = 0;

    
Constant used for registerKeyboardAction that
means that the command should be invoked when the receiving
component is an ancestor of the focused component or is
itself the focused component.

/**
     * Constant used for <code>registerKeyboardAction</code> that
     * means that the command should be invoked when the receiving
     * component is an ancestor of the focused component or is
     * itself the focused component.
     */
    public static final int WHEN_ANCESTOR_OF_FOCUSED_COMPONENT = 1;

    
Constant used for registerKeyboardAction that
means that the command should be invoked when
the receiving component is in the window that has the focus
or is itself the focused component.

/**
     * Constant used for <code>registerKeyboardAction</code> that
     * means that the command should be invoked when
     * the receiving component is in the window that has the focus
     * or is itself the focused component.
     */
    public static final int WHEN_IN_FOCUSED_WINDOW = 2;

    
Constant used by some of the APIs to mean that no condition is defined.

/**
     * Constant used by some of the APIs to mean that no condition is defined.
     */
    public static final int UNDEFINED_CONDITION = -1;

    
The key used by JComponent to access keyboard bindings.

/**
     * The key used by <code>JComponent</code> to access keyboard bindings.
     */
    private static final String KEYBOARD_BINDINGS_KEY = "_KeyboardBindings";

    
An array of KeyStrokes used for
WHEN_IN_FOCUSED_WINDOW are stashed
in the client properties under this string.

/**
     * An array of <code>KeyStroke</code>s used for
     * <code>WHEN_IN_FOCUSED_WINDOW</code> are stashed
     * in the client properties under this string.
     */
    private static final String WHEN_IN_FOCUSED_WINDOW_BINDINGS = "_WhenInFocusedWindow";

    
The comment to display when the cursor is over the component,
also known as a "value tip", "flyover help", or "flyover label".

/**
     * The comment to display when the cursor is over the component,
     * also known as a "value tip", "flyover help", or "flyover label".
     */
    public static final String TOOL_TIP_TEXT_KEY = "ToolTipText";

    private static final String NEXT_FOCUS = "nextFocus";

    
JPopupMenu assigned to this component
and all of its children

/**
     * <code>JPopupMenu</code> assigned to this component
     * and all of its children
     */
    private JPopupMenu popupMenu;

    
Private flags 
/** Private flags **/
    private static final int IS_DOUBLE_BUFFERED                       =  0;
    private static final int ANCESTOR_USING_BUFFER                    =  1;
    private static final int IS_PAINTING_TILE                         =  2;
    private static final int IS_OPAQUE                                =  3;
    private static final int KEY_EVENTS_ENABLED                       =  4;
    private static final int FOCUS_INPUTMAP_CREATED                   =  5;
    private static final int ANCESTOR_INPUTMAP_CREATED                =  6;
    private static final int WIF_INPUTMAP_CREATED                     =  7;
    private static final int ACTIONMAP_CREATED                        =  8;
    private static final int CREATED_DOUBLE_BUFFER                    =  9;
    // bit 10 is free
    private static final int IS_PRINTING                              = 11;
    private static final int IS_PRINTING_ALL                          = 12;
    private static final int IS_REPAINTING                            = 13;
    
Bits 14-21 are used to handle nested writeObject calls. 
/** Bits 14-21 are used to handle nested writeObject calls. **/
    private static final int WRITE_OBJ_COUNTER_FIRST                  = 14;
    private static final int RESERVED_1                               = 15;
    private static final int RESERVED_2                               = 16;
    private static final int RESERVED_3                               = 17;
    private static final int RESERVED_4                               = 18;
    private static final int RESERVED_5                               = 19;
    private static final int RESERVED_6                               = 20;
    private static final int WRITE_OBJ_COUNTER_LAST                   = 21;

    private static final int REQUEST_FOCUS_DISABLED                   = 22;
    private static final int INHERITS_POPUP_MENU                      = 23;
    private static final int OPAQUE_SET                               = 24;
    private static final int AUTOSCROLLS_SET                          = 25;
    private static final int FOCUS_TRAVERSAL_KEYS_FORWARD_SET         = 26;
    private static final int FOCUS_TRAVERSAL_KEYS_BACKWARD_SET        = 27;

    private transient AtomicBoolean revalidateRunnableScheduled = new AtomicBoolean(false);

    
Temporary rectangles.

/**
     * Temporary rectangles.
     */
    private static java.util.List<Rectangle> tempRectangles = new java.util.ArrayList<Rectangle>(11);

    
Used for WHEN_FOCUSED bindings. 
/** Used for <code>WHEN_FOCUSED</code> bindings. */
    private InputMap focusInputMap;
    
Used for WHEN_ANCESTOR_OF_FOCUSED_COMPONENT bindings. 
/** Used for <code>WHEN_ANCESTOR_OF_FOCUSED_COMPONENT</code> bindings. */
    private InputMap ancestorInputMap;
    
Used for WHEN_IN_FOCUSED_KEY bindings. 
/** Used for <code>WHEN_IN_FOCUSED_KEY</code> bindings. */
    private ComponentInputMap windowInputMap;

    
ActionMap. 
/** ActionMap. */
    private ActionMap actionMap;

    
Key used to store the default locale in an AppContext 
/** Key used to store the default locale in an AppContext **/
    private static final String defaultLocale = "JComponent.defaultLocale";

    private static Component componentObtainingGraphicsFrom;
    private static Object componentObtainingGraphicsFromLock = new
            StringBuilder("componentObtainingGraphicsFrom");

    
AA text hints.

/**
     * AA text hints.
     */
    private transient Object aaHint;
    private transient Object lcdRenderingHint;

    static {
        SwingAccessor.setJComponentAccessor(new SwingAccessor.JComponentAccessor() {

            @Override
            public boolean getFlag(JComponent comp, int aFlag) {
                return comp.getFlag(aFlag);
            }

            @Override
            public void compWriteObjectNotify(JComponent comp) {
                comp.compWriteObjectNotify();
            }
        });
    }

    static Graphics safelyGetGraphics(Component c) {
        return safelyGetGraphics(c, SwingUtilities.getRoot(c));
    }

    static Graphics safelyGetGraphics(Component c, Component root) {
        synchronized(componentObtainingGraphicsFromLock) {
            componentObtainingGraphicsFrom = root;
            Graphics g = c.getGraphics();
            componentObtainingGraphicsFrom = null;
            return g;
        }
    }

    static void getGraphicsInvoked(Component root) {
        if (!JComponent.isComponentObtainingGraphicsFrom(root)) {
            JRootPane rootPane = ((RootPaneContainer)root).getRootPane();
            if (rootPane != null) {
                rootPane.disableTrueDoubleBuffering();
            }
        }
    }


    
Returns true if c is the component the graphics is being requested of. This is intended for use when getGraphics is invoked. 
/**
     * Returns true if {@code c} is the component the graphics is being
     * requested of. This is intended for use when getGraphics is invoked.
     */
    private static boolean isComponentObtainingGraphicsFrom(Component c) {
        synchronized(componentObtainingGraphicsFromLock) {
            return (componentObtainingGraphicsFrom == c);
        }
    }

    
Returns the Set of KeyStrokes to use if the component
is managing focus for forward focus traversal.

/**
     * Returns the Set of <code>KeyStroke</code>s to use if the component
     * is managing focus for forward focus traversal.
     */
    @SuppressWarnings("deprecation")
    static Set<KeyStroke> getManagingFocusForwardTraversalKeys() {
        synchronized(JComponent.class) {
            if (managingFocusForwardTraversalKeys == null) {
                managingFocusForwardTraversalKeys = new HashSet<KeyStroke>(1);
                managingFocusForwardTraversalKeys.add(
                    KeyStroke.getKeyStroke(KeyEvent.VK_TAB,
                                           InputEvent.CTRL_MASK));
            }
        }
        return managingFocusForwardTraversalKeys;
    }

    
Returns the Set of KeyStrokes to use if the component
is managing focus for backward focus traversal.

/**
     * Returns the Set of <code>KeyStroke</code>s to use if the component
     * is managing focus for backward focus traversal.
     */
    @SuppressWarnings("deprecation")
    static Set<KeyStroke> getManagingFocusBackwardTraversalKeys() {
        synchronized(JComponent.class) {
            if (managingFocusBackwardTraversalKeys == null) {
                managingFocusBackwardTraversalKeys = new HashSet<KeyStroke>(1);
                managingFocusBackwardTraversalKeys.add(
                    KeyStroke.getKeyStroke(KeyEvent.VK_TAB,
                                           InputEvent.SHIFT_MASK |
                                           InputEvent.CTRL_MASK));
            }
        }
        return managingFocusBackwardTraversalKeys;
    }

    private static Rectangle fetchRectangle() {
        synchronized(tempRectangles) {
            Rectangle rect;
            int size = tempRectangles.size();
            if (size > 0) {
                rect = tempRectangles.remove(size - 1);
            }
            else {
                rect = new Rectangle(0, 0, 0, 0);
            }
            return rect;
        }
    }

    private static void recycleRectangle(Rectangle rect) {
        synchronized(tempRectangles) {
            tempRectangles.add(rect);
        }
    }

    
Sets whether or not getComponentPopupMenu should delegate
to the parent if this component does not have a JPopupMenu
assigned to it.


The default value for this is false, but some JComponent
subclasses that are implemented as a number of JComponents
may set this to true.


This is a bound property.

Params:
  • value – whether or not the JPopupMenu is inherited
See Also:
Since:1.5
/**
     * Sets whether or not <code>getComponentPopupMenu</code> should delegate
     * to the parent if this component does not have a <code>JPopupMenu</code>
     * assigned to it.
     * <p>
     * The default value for this is false, but some <code>JComponent</code>
     * subclasses that are implemented as a number of <code>JComponent</code>s
     * may set this to true.
     * <p>
     * This is a bound property.
     *
     * @param value whether or not the JPopupMenu is inherited
     * @see #setComponentPopupMenu
     * @since 1.5
     */
    @BeanProperty(description
            = "Whether or not the JPopupMenu is inherited")
    public void setInheritsPopupMenu(boolean value) {
        boolean oldValue = getFlag(INHERITS_POPUP_MENU);
        setFlag(INHERITS_POPUP_MENU, value);
        firePropertyChange("inheritsPopupMenu", oldValue, value);
    }

    
Returns true if the JPopupMenu should be inherited from the parent.

See Also:
Returns:true if the JPopupMenu should be inherited from the parent
Since:1.5
/**
     * Returns true if the JPopupMenu should be inherited from the parent.
     *
     * @return true if the JPopupMenu should be inherited from the parent
     * @see #setComponentPopupMenu
     * @since 1.5
     */
    public boolean getInheritsPopupMenu() {
        return getFlag(INHERITS_POPUP_MENU);
    }

    
Sets the JPopupMenu for this JComponent.
The UI is responsible for registering bindings and adding the necessary
listeners such that the JPopupMenu will be shown at
the appropriate time. When the JPopupMenu is shown
depends upon the look and feel: some may show it on a mouse event,
some may enable a key binding.


If popup is null, and getInheritsPopupMenu
returns true, then getComponentPopupMenu will be delegated
to the parent. This provides for a way to make all child components
inherit the popupmenu of the parent.


This is a bound property.

Params:
  • popup – - the popup that will be assigned to this component
               may be null
See Also:
Since:1.5
/**
     * Sets the <code>JPopupMenu</code> for this <code>JComponent</code>.
     * The UI is responsible for registering bindings and adding the necessary
     * listeners such that the <code>JPopupMenu</code> will be shown at
     * the appropriate time. When the <code>JPopupMenu</code> is shown
     * depends upon the look and feel: some may show it on a mouse event,
     * some may enable a key binding.
     * <p>
     * If <code>popup</code> is null, and <code>getInheritsPopupMenu</code>
     * returns true, then <code>getComponentPopupMenu</code> will be delegated
     * to the parent. This provides for a way to make all child components
     * inherit the popupmenu of the parent.
     * <p>
     * This is a bound property.
     *
     * @param popup - the popup that will be assigned to this component
     *                may be null
     * @see #getComponentPopupMenu
     * @since 1.5
     */
    @BeanProperty(preferred = true, description
            = "Popup to show")
    public void setComponentPopupMenu(JPopupMenu popup) {
        if(popup != null) {
            enableEvents(AWTEvent.MOUSE_EVENT_MASK);
        }
        JPopupMenu oldPopup = this.popupMenu;
        this.popupMenu = popup;
        firePropertyChange("componentPopupMenu", oldPopup, popup);
    }

    
Returns JPopupMenu that assigned for this component.
If this component does not have a JPopupMenu assigned
to it and getInheritsPopupMenu is true, this
will return getParent().getComponentPopupMenu() (assuming
the parent is valid.)

See Also:
Returns:JPopupMenu assigned for this component
        or null if no popup assigned
Since:1.5
/**
     * Returns <code>JPopupMenu</code> that assigned for this component.
     * If this component does not have a <code>JPopupMenu</code> assigned
     * to it and <code>getInheritsPopupMenu</code> is true, this
     * will return <code>getParent().getComponentPopupMenu()</code> (assuming
     * the parent is valid.)
     *
     * @return <code>JPopupMenu</code> assigned for this component
     *         or <code>null</code> if no popup assigned
     * @see #setComponentPopupMenu
     * @since 1.5
     */
    @SuppressWarnings("deprecation")
    public JPopupMenu getComponentPopupMenu() {

        if(!getInheritsPopupMenu()) {
            return popupMenu;
        }

        if(popupMenu == null) {
            // Search parents for its popup
            Container parent = getParent();
            while (parent != null) {
                if(parent instanceof JComponent) {
                    return ((JComponent)parent).getComponentPopupMenu();
                }
                if(parent instanceof Window ||
                   parent instanceof Applet) {
                    // Reached toplevel, break and return null
                    break;
                }
                parent = parent.getParent();
            }
            return null;
        }

        return popupMenu;
    }

    
Default JComponent constructor.  This constructor does
very little initialization beyond calling the Container
constructor.  For example, the initial layout manager is
null. It does, however, set the component's locale
property to the value returned by
JComponent.getDefaultLocale.

See Also:
  • getDefaultLocale
/**
     * Default <code>JComponent</code> constructor.  This constructor does
     * very little initialization beyond calling the <code>Container</code>
     * constructor.  For example, the initial layout manager is
     * <code>null</code>. It does, however, set the component's locale
     * property to the value returned by
     * <code>JComponent.getDefaultLocale</code>.
     *
     * @see #getDefaultLocale
     */
    public JComponent() {
        super();
        // We enable key events on all JComponents so that accessibility
        // bindings will work everywhere. This is a partial fix to BugID
        // 4282211.
        enableEvents(AWTEvent.KEY_EVENT_MASK);
        if (isManagingFocus()) {
            LookAndFeel.installProperty(this,
                                        "focusTraversalKeysForward",
                                  getManagingFocusForwardTraversalKeys());
            LookAndFeel.installProperty(this,
                                        "focusTraversalKeysBackward",
                                  getManagingFocusBackwardTraversalKeys());
        }

        super.setLocale( JComponent.getDefaultLocale() );
    }


    
Resets the UI property to a value from the current look and feel.
JComponent subclasses must override this method
like this:

  public void updateUI() {
     setUI((SliderUI)UIManager.getUI(this);
  }
 


See Also:
/**
     * Resets the UI property to a value from the current look and feel.
     * <code>JComponent</code> subclasses must override this method
     * like this:
     * <pre>
     *   public void updateUI() {
     *      setUI((SliderUI)UIManager.getUI(this);
     *   }
     *  </pre>
     *
     * @see #setUI
     * @see UIManager#getLookAndFeel
     * @see UIManager#getUI
     */
    public void updateUI() {}

    
Returns the look and feel delegate that renders this component.

Returns:the ComponentUI object that renders this component
Since:9
/**
     * Returns the look and feel delegate that renders this component.
     *
     * @return the {@code ComponentUI} object that renders this component
     * @since 9
     */
    @Transient
    public ComponentUI getUI() {
        return ui;
    }

    
Sets the look and feel delegate for this component.
JComponent subclasses generally override this method
to narrow the argument type. For example, in JSlider:

public void setUI(SliderUI newUI) {
    super.setUI(newUI);
}
 



Additionally JComponent subclasses must provide a
getUI method that returns the correct type.  For example:

public SliderUI getUI() {
    return (SliderUI)ui;
}



Params:
  • newUI – the new UI delegate
See Also:
/**
     * Sets the look and feel delegate for this component.
     * <code>JComponent</code> subclasses generally override this method
     * to narrow the argument type. For example, in <code>JSlider</code>:
     * <pre>
     * public void setUI(SliderUI newUI) {
     *     super.setUI(newUI);
     * }
     *  </pre>
     * <p>
     * Additionally <code>JComponent</code> subclasses must provide a
     * <code>getUI</code> method that returns the correct type.  For example:
     * <pre>
     * public SliderUI getUI() {
     *     return (SliderUI)ui;
     * }
     * </pre>
     *
     * @param newUI the new UI delegate
     * @see #updateUI
     * @see UIManager#getLookAndFeel
     * @see UIManager#getUI
     */
    @BeanProperty(hidden = true, visualUpdate = true, description
            = "The component's look and feel delegate.")
    protected void setUI(ComponentUI newUI) {
        /* We do not check that the UI instance is different
         * before allowing the switch in order to enable the
         * same UI instance *with different default settings*
         * to be installed.
         */

        uninstallUIAndProperties();

        // aaText shouldn't persist between look and feels, reset it.
        aaHint = UIManager.getDefaults().get(
                RenderingHints.KEY_TEXT_ANTIALIASING);
        lcdRenderingHint = UIManager.getDefaults().get(
                RenderingHints.KEY_TEXT_LCD_CONTRAST);
        ComponentUI oldUI = ui;
        ui = newUI;
        if (ui != null) {
            ui.installUI(this);
        }

        firePropertyChange("UI", oldUI, newUI);
        revalidate();
        repaint();
    }

    
Uninstalls the UI, if any, and any client properties designated as being specific to the installed UI - instances of UIClientPropertyKey. 
/**
     * Uninstalls the UI, if any, and any client properties designated
     * as being specific to the installed UI - instances of
     * {@code UIClientPropertyKey}.
     */
    private void uninstallUIAndProperties() {
        if (ui != null) {
            ui.uninstallUI(this);
            //clean UIClientPropertyKeys from client properties
            if (clientProperties != null) {
                synchronized(clientProperties) {
                    Object[] clientPropertyKeys =
                        clientProperties.getKeys(null);
                    if (clientPropertyKeys != null) {
                        for (Object key : clientPropertyKeys) {
                            if (key instanceof UIClientPropertyKey) {
                                putClientProperty(key, null);
                            }
                        }
                    }
                }
            }
        }
    }

    
Returns the UIDefaults key used to
look up the name of the swing.plaf.ComponentUI
class that defines the look and feel
for this component.  Most applications will never need to
call this method.  Subclasses of JComponent that support
pluggable look and feel should override this method to
return a UIDefaults key that maps to the
ComponentUI subclass that defines their look and feel.

See Also:
Returns:the UIDefaults key for a
         ComponentUI subclass
/**
     * Returns the <code>UIDefaults</code> key used to
     * look up the name of the <code>swing.plaf.ComponentUI</code>
     * class that defines the look and feel
     * for this component.  Most applications will never need to
     * call this method.  Subclasses of <code>JComponent</code> that support
     * pluggable look and feel should override this method to
     * return a <code>UIDefaults</code> key that maps to the
     * <code>ComponentUI</code> subclass that defines their look and feel.
     *
     * @return the <code>UIDefaults</code> key for a
     *          <code>ComponentUI</code> subclass
     * @see UIDefaults#getUI
     */
    @BeanProperty(bound = false, expert = true, description
            = "UIClassID")
    public String getUIClassID() {
        return uiClassID;
    }


    
Returns the graphics object used to paint this component.
If DebugGraphics is turned on we create a new
DebugGraphics object if necessary.
Otherwise we just configure the
specified graphics object's foreground and font.

Params:
  • g – the original Graphics object
Returns:a Graphics object configured for this component
/**
     * Returns the graphics object used to paint this component.
     * If <code>DebugGraphics</code> is turned on we create a new
     * <code>DebugGraphics</code> object if necessary.
     * Otherwise we just configure the
     * specified graphics object's foreground and font.
     *
     * @param g the original <code>Graphics</code> object
     * @return a <code>Graphics</code> object configured for this component
     */
    protected Graphics getComponentGraphics(Graphics g) {
        Graphics componentGraphics = g;
        if (ui != null && DEBUG_GRAPHICS_LOADED) {
            if ((DebugGraphics.debugComponentCount() != 0) &&
                    (shouldDebugGraphics() != 0) &&
                    !(g instanceof DebugGraphics)) {
                componentGraphics = new DebugGraphics(g,this);
            }
        }
        componentGraphics.setColor(getForeground());
        componentGraphics.setFont(getFont());

        return componentGraphics;
    }


    
Calls the UI delegate's paint method, if the UI delegate
is non-null.  We pass the delegate a copy of the
Graphics object to protect the rest of the
paint code from irrevocable changes
(for example, Graphics.translate).


If you override this in a subclass you should not make permanent
changes to the passed in Graphics. For example, you
should not alter the clip Rectangle or modify the
transform. If you need to do these operations you may find it
easier to create a new Graphics from the passed in
Graphics and manipulate it. Further, if you do not
invoke super's implementation you must honor the opaque property, that is
if this component is opaque, you must completely fill in the background
in an opaque color. If you do not honor the opaque property you
will likely see visual artifacts.


The passed in Graphics object might
have a transform other than the identify transform
installed on it.  In this case, you might get
unexpected results if you cumulatively apply
another transform.

Params:
  • g – the Graphics object to protect
See Also:
/**
     * Calls the UI delegate's paint method, if the UI delegate
     * is non-<code>null</code>.  We pass the delegate a copy of the
     * <code>Graphics</code> object to protect the rest of the
     * paint code from irrevocable changes
     * (for example, <code>Graphics.translate</code>).
     * <p>
     * If you override this in a subclass you should not make permanent
     * changes to the passed in <code>Graphics</code>. For example, you
     * should not alter the clip <code>Rectangle</code> or modify the
     * transform. If you need to do these operations you may find it
     * easier to create a new <code>Graphics</code> from the passed in
     * <code>Graphics</code> and manipulate it. Further, if you do not
     * invoke super's implementation you must honor the opaque property, that is
     * if this component is opaque, you must completely fill in the background
     * in an opaque color. If you do not honor the opaque property you
     * will likely see visual artifacts.
     * <p>
     * The passed in <code>Graphics</code> object might
     * have a transform other than the identify transform
     * installed on it.  In this case, you might get
     * unexpected results if you cumulatively apply
     * another transform.
     *
     * @param g the <code>Graphics</code> object to protect
     * @see #paint
     * @see ComponentUI
     */
    protected void paintComponent(Graphics g) {
        if (ui != null) {
            Graphics scratchGraphics = (g == null) ? null : g.create();
            try {
                ui.update(scratchGraphics, this);
            }
            finally {
                scratchGraphics.dispose();
            }
        }
    }

    
Paints this component's children.
If shouldUseBuffer is true,
no component ancestor has a buffer and
the component children can use a buffer if they have one.
Otherwise, one ancestor has a buffer currently in use and children
should not use a buffer to paint.

Params:
  • g –  the Graphics context in which to paint
See Also:
/**
     * Paints this component's children.
     * If <code>shouldUseBuffer</code> is true,
     * no component ancestor has a buffer and
     * the component children can use a buffer if they have one.
     * Otherwise, one ancestor has a buffer currently in use and children
     * should not use a buffer to paint.
     * @param g  the <code>Graphics</code> context in which to paint
     * @see #paint
     * @see java.awt.Container#paint
     */
    protected void paintChildren(Graphics g) {
        Graphics sg = g;

        synchronized(getTreeLock()) {
            int i = getComponentCount() - 1;
            if (i < 0) {
                return;
            }
            // If we are only to paint to a specific child, determine
            // its index.
            if (paintingChild != null &&
                (paintingChild instanceof JComponent) &&
                paintingChild.isOpaque()) {
                for (; i >= 0; i--) {
                    if (getComponent(i) == paintingChild){
                        break;
                    }
                }
            }
            Rectangle tmpRect = fetchRectangle();
            boolean checkSiblings = (!isOptimizedDrawingEnabled() &&
                                     checkIfChildObscuredBySibling());
            Rectangle clipBounds = null;
            if (checkSiblings) {
                clipBounds = sg.getClipBounds();
                if (clipBounds == null) {
                    clipBounds = new Rectangle(0, 0, getWidth(),
                                               getHeight());
                }
            }
            boolean printing = getFlag(IS_PRINTING);
            final Window window = SwingUtilities.getWindowAncestor(this);
            final boolean isWindowOpaque = window == null || window.isOpaque();
            for (; i >= 0 ; i--) {
                Component comp = getComponent(i);
                if (comp == null) {
                    continue;
                }

                final boolean isJComponent = comp instanceof JComponent;

                // Enable painting of heavyweights in non-opaque windows.
                // See 6884960
                if ((!isWindowOpaque || isJComponent ||
                            isLightweightComponent(comp)) && comp.isVisible())
                {
                    Rectangle cr;

                    cr = comp.getBounds(tmpRect);
                    Shape clip = g.getClip();
                    boolean hitClip = (clip != null)
                            ? clip.intersects(cr.x, cr.y, cr.width, cr.height)
                            : true;

                    if (hitClip) {
                        if (checkSiblings && i > 0) {
                            int x = cr.x;
                            int y = cr.y;
                            int width = cr.width;
                            int height = cr.height;
                            SwingUtilities.computeIntersection
                                (clipBounds.x, clipBounds.y,
                                 clipBounds.width, clipBounds.height, cr);

                            if(getObscuredState(i, cr.x, cr.y, cr.width,
                                          cr.height) == COMPLETELY_OBSCURED) {
                                continue;
                            }
                            cr.x = x;
                            cr.y = y;
                            cr.width = width;
                            cr.height = height;
                        }
                        Graphics cg = sg.create(cr.x, cr.y, cr.width,
                                                cr.height);
                        cg.setColor(comp.getForeground());
                        cg.setFont(comp.getFont());
                        boolean shouldSetFlagBack = false;
                        try {
                            if(isJComponent) {
                                if(getFlag(ANCESTOR_USING_BUFFER)) {
                                    ((JComponent)comp).setFlag(
                                                 ANCESTOR_USING_BUFFER,true);
                                    shouldSetFlagBack = true;
                                }
                                if(getFlag(IS_PAINTING_TILE)) {
                                    ((JComponent)comp).setFlag(
                                                 IS_PAINTING_TILE,true);
                                    shouldSetFlagBack = true;
                                }
                                if(!printing) {
                                    comp.paint(cg);
                                }
                                else {
                                    if (!getFlag(IS_PRINTING_ALL)) {
                                        comp.print(cg);
                                    }
                                    else {
                                        comp.printAll(cg);
                                    }
                                }
                            } else {
                                // The component is either lightweight, or
                                // heavyweight in a non-opaque window
                                if (!printing) {
                                    comp.paint(cg);
                                }
                                else {
                                    if (!getFlag(IS_PRINTING_ALL)) {
                                        comp.print(cg);
                                    }
                                    else {
                                        comp.printAll(cg);
                                    }
                                }
                            }
                        } finally {
                            cg.dispose();
                            if(shouldSetFlagBack) {
                                ((JComponent)comp).setFlag(
                                             ANCESTOR_USING_BUFFER,false);
                                ((JComponent)comp).setFlag(
                                             IS_PAINTING_TILE,false);
                            }
                        }
                    }
                }

            }
            recycleRectangle(tmpRect);
        }
    }

    
Paints the component's border.


If you override this in a subclass you should not make permanent
changes to the passed in Graphics. For example, you
should not alter the clip Rectangle or modify the
transform. If you need to do these operations you may find it
easier to create a new Graphics from the passed in
Graphics and manipulate it.

Params:
  • g –  the Graphics context in which to paint
See Also:
/**
     * Paints the component's border.
     * <p>
     * If you override this in a subclass you should not make permanent
     * changes to the passed in <code>Graphics</code>. For example, you
     * should not alter the clip <code>Rectangle</code> or modify the
     * transform. If you need to do these operations you may find it
     * easier to create a new <code>Graphics</code> from the passed in
     * <code>Graphics</code> and manipulate it.
     *
     * @param g  the <code>Graphics</code> context in which to paint
     *
     * @see #paint
     * @see #setBorder
     */
    protected void paintBorder(Graphics g) {
        Border border = getBorder();
        if (border != null) {
            border.paintBorder(this, g, 0, 0, getWidth(), getHeight());
        }
    }


    
Calls paint.  Doesn't clear the background but see
ComponentUI.update, which is called by
paintComponent.

Params:
  • g – the Graphics context in which to paint
See Also:
/**
     * Calls <code>paint</code>.  Doesn't clear the background but see
     * <code>ComponentUI.update</code>, which is called by
     * <code>paintComponent</code>.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #paint
     * @see #paintComponent
     * @see javax.swing.plaf.ComponentUI
     */
    public void update(Graphics g) {
        paint(g);
    }


    
Invoked by Swing to draw components.
Applications should not invoke paint directly,
but should instead use the repaint method to
schedule the component for redrawing.


This method actually delegates the work of painting to three
protected methods: paintComponent,
paintBorder,
and paintChildren.  They're called in the order
listed to ensure that children appear on top of component itself.
Generally speaking, the component and its children should not
paint in the insets area allocated to the border. Subclasses can
just override this method, as always.  A subclass that just
wants to specialize the UI (look and feel) delegate's
paint method should just override
paintComponent.

Params:
  • g –  the Graphics context in which to paint
See Also:
/**
     * Invoked by Swing to draw components.
     * Applications should not invoke <code>paint</code> directly,
     * but should instead use the <code>repaint</code> method to
     * schedule the component for redrawing.
     * <p>
     * This method actually delegates the work of painting to three
     * protected methods: <code>paintComponent</code>,
     * <code>paintBorder</code>,
     * and <code>paintChildren</code>.  They're called in the order
     * listed to ensure that children appear on top of component itself.
     * Generally speaking, the component and its children should not
     * paint in the insets area allocated to the border. Subclasses can
     * just override this method, as always.  A subclass that just
     * wants to specialize the UI (look and feel) delegate's
     * <code>paint</code> method should just override
     * <code>paintComponent</code>.
     *
     * @param g  the <code>Graphics</code> context in which to paint
     * @see #paintComponent
     * @see #paintBorder
     * @see #paintChildren
     * @see #getComponentGraphics
     * @see #repaint
     */
    public void paint(Graphics g) {
        boolean shouldClearPaintFlags = false;

        if ((getWidth() <= 0) || (getHeight() <= 0)) {
            return;
        }

        Graphics componentGraphics = getComponentGraphics(g);
        Graphics co = componentGraphics.create();
        try {
            RepaintManager repaintManager = RepaintManager.currentManager(this);
            Rectangle clipRect = co.getClipBounds();
            int clipX;
            int clipY;
            int clipW;
            int clipH;
            if (clipRect == null) {
                clipX = clipY = 0;
                clipW = getWidth();
                clipH = getHeight();
            }
            else {
                clipX = clipRect.x;
                clipY = clipRect.y;
                clipW = clipRect.width;
                clipH = clipRect.height;
            }

            if(clipW > getWidth()) {
                clipW = getWidth();
            }
            if(clipH > getHeight()) {
                clipH = getHeight();
            }

            if(getParent() != null && !(getParent() instanceof JComponent)) {
                adjustPaintFlags();
                shouldClearPaintFlags = true;
            }

            int bw,bh;
            boolean printing = getFlag(IS_PRINTING);
            if (!printing && repaintManager.isDoubleBufferingEnabled() &&
                !getFlag(ANCESTOR_USING_BUFFER) && isDoubleBuffered() &&
                (getFlag(IS_REPAINTING) || repaintManager.isPainting()))
            {
                repaintManager.beginPaint();
                try {
                    repaintManager.paint(this, this, co, clipX, clipY, clipW,
                                         clipH);
                } finally {
                    repaintManager.endPaint();
                }
            }
            else {
                // Will ocassionaly happen in 1.2, especially when printing.
                if (clipRect == null) {
                    co.setClip(clipX, clipY, clipW, clipH);
                }

                if (!rectangleIsObscured(clipX,clipY,clipW,clipH)) {
                    if (!printing) {
                        paintComponent(co);
                        paintBorder(co);
                    }
                    else {
                        printComponent(co);
                        printBorder(co);
                    }
                }
                if (!printing) {
                    paintChildren(co);
                }
                else {
                    printChildren(co);
                }
            }
        } finally {
            co.dispose();
            if(shouldClearPaintFlags) {
                setFlag(ANCESTOR_USING_BUFFER,false);
                setFlag(IS_PAINTING_TILE,false);
                setFlag(IS_PRINTING,false);
                setFlag(IS_PRINTING_ALL,false);
            }
        }
    }

    // paint forcing use of the double buffer.  This is used for historical
    // reasons: JViewport, when scrolling, previously directly invoked paint
    // while turning off double buffering at the RepaintManager level, this
    // codes simulates that.
    void paintForceDoubleBuffered(Graphics g) {
        RepaintManager rm = RepaintManager.currentManager(this);
        Rectangle clip = g.getClipBounds();
        rm.beginPaint();
        setFlag(IS_REPAINTING, true);
        try {
            rm.paint(this, this, g, clip.x, clip.y, clip.width, clip.height);
        } finally {
            rm.endPaint();
            setFlag(IS_REPAINTING, false);
        }
    }

    
Returns true if this component, or any of its ancestors, are in
the processing of painting.

/**
     * Returns true if this component, or any of its ancestors, are in
     * the processing of painting.
     */
    boolean isPainting() {
        Container component = this;
        while (component != null) {
            if (component instanceof JComponent &&
                   ((JComponent)component).getFlag(ANCESTOR_USING_BUFFER)) {
                return true;
            }
            component = component.getParent();
        }
        return false;
    }

    private void adjustPaintFlags() {
        JComponent jparent;
        Container parent;
        for(parent = getParent() ; parent != null ; parent =
            parent.getParent()) {
            if(parent instanceof JComponent) {
                jparent = (JComponent) parent;
                if(jparent.getFlag(ANCESTOR_USING_BUFFER))
                  setFlag(ANCESTOR_USING_BUFFER, true);
                if(jparent.getFlag(IS_PAINTING_TILE))
                  setFlag(IS_PAINTING_TILE, true);
                if(jparent.getFlag(IS_PRINTING))
                  setFlag(IS_PRINTING, true);
                if(jparent.getFlag(IS_PRINTING_ALL))
                  setFlag(IS_PRINTING_ALL, true);
                break;
            }
        }
    }

    
Invoke this method to print the component. This method invokes
print on the component.

Params:
  • g – the Graphics context in which to paint
See Also:
/**
     * Invoke this method to print the component. This method invokes
     * <code>print</code> on the component.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #print
     * @see #printComponent
     * @see #printBorder
     * @see #printChildren
     */
    public void printAll(Graphics g) {
        setFlag(IS_PRINTING_ALL, true);
        try {
            print(g);
        }
        finally {
            setFlag(IS_PRINTING_ALL, false);
        }
    }

    
Invoke this method to print the component to the specified
Graphics. This method will result in invocations
of printComponent, printBorder and
printChildren. It is recommended that you override
one of the previously mentioned methods rather than this one if
your intention is to customize the way printing looks. However,
it can be useful to override this method should you want to prepare
state before invoking the superclass behavior. As an example,
if you wanted to change the component's background color before
printing, you could do the following:

    public void print(Graphics g) {
        Color orig = getBackground();
        setBackground(Color.WHITE);
        // wrap in try/finally so that we always restore the state
        try {
            super.print(g);
        } finally {
            setBackground(orig);
        }
    }




Alternatively, or for components that delegate painting to other objects,
you can query during painting whether or not the component is in the
midst of a print operation. The isPaintingForPrint method provides
this ability and its return value will be changed by this method: to
true immediately before rendering and to false
immediately after. With each change a property change event is fired on
this component with the name "paintingForPrint".


This method sets the component's state such that the double buffer
will not be used: painting will be done directly on the passed in
Graphics.

Params:
  • g – the Graphics context in which to paint
See Also:
/**
     * Invoke this method to print the component to the specified
     * <code>Graphics</code>. This method will result in invocations
     * of <code>printComponent</code>, <code>printBorder</code> and
     * <code>printChildren</code>. It is recommended that you override
     * one of the previously mentioned methods rather than this one if
     * your intention is to customize the way printing looks. However,
     * it can be useful to override this method should you want to prepare
     * state before invoking the superclass behavior. As an example,
     * if you wanted to change the component's background color before
     * printing, you could do the following:
     * <pre>
     *     public void print(Graphics g) {
     *         Color orig = getBackground();
     *         setBackground(Color.WHITE);
     *
     *         // wrap in try/finally so that we always restore the state
     *         try {
     *             super.print(g);
     *         } finally {
     *             setBackground(orig);
     *         }
     *     }
     * </pre>
     * <p>
     * Alternatively, or for components that delegate painting to other objects,
     * you can query during painting whether or not the component is in the
     * midst of a print operation. The <code>isPaintingForPrint</code> method provides
     * this ability and its return value will be changed by this method: to
     * <code>true</code> immediately before rendering and to <code>false</code>
     * immediately after. With each change a property change event is fired on
     * this component with the name <code>"paintingForPrint"</code>.
     * <p>
     * This method sets the component's state such that the double buffer
     * will not be used: painting will be done directly on the passed in
     * <code>Graphics</code>.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #printComponent
     * @see #printBorder
     * @see #printChildren
     * @see #isPaintingForPrint
     */
    public void print(Graphics g) {
        setFlag(IS_PRINTING, true);
        firePropertyChange("paintingForPrint", false, true);
        try {
            paint(g);
        }
        finally {
            setFlag(IS_PRINTING, false);
            firePropertyChange("paintingForPrint", true, false);
        }
    }

    
This is invoked during a printing operation. This is implemented to
invoke paintComponent on the component. Override this
if you wish to add special painting behavior when printing.

Params:
  • g – the Graphics context in which to paint
See Also:
Since:1.3
/**
     * This is invoked during a printing operation. This is implemented to
     * invoke <code>paintComponent</code> on the component. Override this
     * if you wish to add special painting behavior when printing.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #print
     * @since 1.3
     */
    protected void printComponent(Graphics g) {
        paintComponent(g);
    }

    
Prints this component's children. This is implemented to invoke
paintChildren on the component. Override this if you
wish to print the children differently than painting.

Params:
  • g – the Graphics context in which to paint
See Also:
Since:1.3
/**
     * Prints this component's children. This is implemented to invoke
     * <code>paintChildren</code> on the component. Override this if you
     * wish to print the children differently than painting.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #print
     * @since 1.3
     */
    protected void printChildren(Graphics g) {
        paintChildren(g);
    }

    
Prints the component's border. This is implemented to invoke
paintBorder on the component. Override this if you
wish to print the border differently that it is painted.

Params:
  • g – the Graphics context in which to paint
See Also:
Since:1.3
/**
     * Prints the component's border. This is implemented to invoke
     * <code>paintBorder</code> on the component. Override this if you
     * wish to print the border differently that it is painted.
     *
     * @param g the <code>Graphics</code> context in which to paint
     * @see #print
     * @since 1.3
     */
    protected void printBorder(Graphics g) {
        paintBorder(g);
    }

    
 Returns true if the component is currently painting a tile.
 If this method returns true, paint will be called again for another
 tile. This method returns false if you are not painting a tile or
 if the last tile is painted.
 Use this method to keep some state you might need between tiles.
 @return  true if the component is currently painting a tile,
         false otherwise

/**
     *  Returns true if the component is currently painting a tile.
     *  If this method returns true, paint will be called again for another
     *  tile. This method returns false if you are not painting a tile or
     *  if the last tile is painted.
     *  Use this method to keep some state you might need between tiles.
     *
     *  @return  true if the component is currently painting a tile,
     *          false otherwise
     */
    @BeanProperty(bound = false)
    public boolean isPaintingTile() {
        return getFlag(IS_PAINTING_TILE);
    }

    
Returns true if the current painting operation on this
component is part of a print operation. This method is
useful when you want to customize what you print versus what you show
on the screen.


You can detect changes in the value of this property by listening for
property change events on this component with name
"paintingForPrint".

 Note: This method provides complimentary functionality to that provided by other high level Swing printing APIs. However, it deals strictly with painting and should not be confused as providing information on higher level print processes. For example, a JTable.print() operation doesn't necessarily result in a continuous rendering of the full component, and the return value of this method can change multiple times during that operation. It is even possible for the component to be painted to the screen while the printing process is ongoing. In such a case, the return value of this method is true when, and only
when, the table is being painted as part of the printing process.

See Also:
Returns:true if the current painting operation on this component
        is part of a print operation
Since:1.6
/**
     * Returns <code>true</code> if the current painting operation on this
     * component is part of a <code>print</code> operation. This method is
     * useful when you want to customize what you print versus what you show
     * on the screen.
     * <p>
     * You can detect changes in the value of this property by listening for
     * property change events on this component with name
     * <code>"paintingForPrint"</code>.
     * <p>
     * Note: This method provides complimentary functionality to that provided
     * by other high level Swing printing APIs. However, it deals strictly with
     * painting and should not be confused as providing information on higher
     * level print processes. For example, a {@link javax.swing.JTable#print()}
     * operation doesn't necessarily result in a continuous rendering of the
     * full component, and the return value of this method can change multiple
     * times during that operation. It is even possible for the component to be
     * painted to the screen while the printing process is ongoing. In such a
     * case, the return value of this method is <code>true</code> when, and only
     * when, the table is being painted as part of the printing process.
     *
     * @return true if the current painting operation on this component
     *         is part of a print operation
     * @see #print
     * @since 1.6
     */
    @BeanProperty(bound = false)
    public final boolean isPaintingForPrint() {
        return getFlag(IS_PRINTING);
    }

    
In release 1.4, the focus subsystem was rearchitected.
For more information, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.


Changes this JComponent's focus traversal keys to
CTRL+TAB and CTRL+SHIFT+TAB. Also prevents
SortingFocusTraversalPolicy from considering descendants
of this JComponent when computing a focus traversal cycle.

See Also:
Returns:false
Deprecated:As of 1.4, replaced by
  Component.setFocusTraversalKeys(int, Set) and
  Container.setFocusCycleRoot(boolean).
/**
     * In release 1.4, the focus subsystem was rearchitected.
     * For more information, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     * <p>
     * Changes this <code>JComponent</code>'s focus traversal keys to
     * CTRL+TAB and CTRL+SHIFT+TAB. Also prevents
     * <code>SortingFocusTraversalPolicy</code> from considering descendants
     * of this JComponent when computing a focus traversal cycle.
     *
     * @return false
     * @see java.awt.Component#setFocusTraversalKeys
     * @see SortingFocusTraversalPolicy
     * @deprecated As of 1.4, replaced by
     *   <code>Component.setFocusTraversalKeys(int, Set)</code> and
     *   <code>Container.setFocusCycleRoot(boolean)</code>.
     */
    @Deprecated
    @BeanProperty(bound = false)
    public boolean isManagingFocus() {
        return false;
    }

    private void registerNextFocusableComponent() {
        registerNextFocusableComponent(getNextFocusableComponent());
    }

    private void registerNextFocusableComponent(Component
                                                nextFocusableComponent) {
        if (nextFocusableComponent == null) {
            return;
        }

        Container nearestRoot =
            (isFocusCycleRoot()) ? this : getFocusCycleRootAncestor();
        FocusTraversalPolicy policy = nearestRoot.getFocusTraversalPolicy();
        if (!(policy instanceof LegacyGlueFocusTraversalPolicy)) {
            policy = new LegacyGlueFocusTraversalPolicy(policy);
            nearestRoot.setFocusTraversalPolicy(policy);
        }
        ((LegacyGlueFocusTraversalPolicy)policy).
            setNextFocusableComponent(this, nextFocusableComponent);
    }

    private void deregisterNextFocusableComponent() {
        Component nextFocusableComponent = getNextFocusableComponent();
        if (nextFocusableComponent == null) {
            return;
        }

        Container nearestRoot =
            (isFocusCycleRoot()) ? this : getFocusCycleRootAncestor();
        if (nearestRoot == null) {
            return;
        }
        FocusTraversalPolicy policy = nearestRoot.getFocusTraversalPolicy();
        if (policy instanceof LegacyGlueFocusTraversalPolicy) {
            ((LegacyGlueFocusTraversalPolicy)policy).
                unsetNextFocusableComponent(this, nextFocusableComponent);
        }
    }

    
In release 1.4, the focus subsystem was rearchitected.
For more information, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.


Overrides the default FocusTraversalPolicy for this
JComponent's focus traversal cycle by unconditionally
setting the specified Component as the next
Component in the cycle, and this JComponent
as the specified Component's previous
Component in the cycle.

Params:
  • aComponent – the Component that should follow this
       JComponent in the focus traversal cycle
See Also:
Deprecated:As of 1.4, replaced by FocusTraversalPolicy
/**
     * In release 1.4, the focus subsystem was rearchitected.
     * For more information, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     * <p>
     * Overrides the default <code>FocusTraversalPolicy</code> for this
     * <code>JComponent</code>'s focus traversal cycle by unconditionally
     * setting the specified <code>Component</code> as the next
     * <code>Component</code> in the cycle, and this <code>JComponent</code>
     * as the specified <code>Component</code>'s previous
     * <code>Component</code> in the cycle.
     *
     * @param aComponent the <code>Component</code> that should follow this
     *        <code>JComponent</code> in the focus traversal cycle
     *
     * @see #getNextFocusableComponent
     * @see java.awt.FocusTraversalPolicy
     * @deprecated As of 1.4, replaced by <code>FocusTraversalPolicy</code>
     */
    @Deprecated
    public void setNextFocusableComponent(Component aComponent) {
        boolean displayable = isDisplayable();
        if (displayable) {
            deregisterNextFocusableComponent();
        }
        putClientProperty(NEXT_FOCUS, aComponent);
        if (displayable) {
            registerNextFocusableComponent(aComponent);
        }
    }

    
In release 1.4, the focus subsystem was rearchitected.
For more information, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.


Returns the Component set by a prior call to
setNextFocusableComponent(Component) on this
JComponent.

See Also:
Returns:the Component that will follow this
       JComponent in the focus traversal cycle, or
       null if none has been explicitly specified
Deprecated:As of 1.4, replaced by FocusTraversalPolicy.
/**
     * In release 1.4, the focus subsystem was rearchitected.
     * For more information, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     * <p>
     * Returns the <code>Component</code> set by a prior call to
     * <code>setNextFocusableComponent(Component)</code> on this
     * <code>JComponent</code>.
     *
     * @return the <code>Component</code> that will follow this
     *        <code>JComponent</code> in the focus traversal cycle, or
     *        <code>null</code> if none has been explicitly specified
     *
     * @see #setNextFocusableComponent
     * @deprecated As of 1.4, replaced by <code>FocusTraversalPolicy</code>.
     */
    @Deprecated
    public Component getNextFocusableComponent() {
        return (Component)getClientProperty(NEXT_FOCUS);
    }

    
Provides a hint as to whether or not this JComponent
should get focus. This is only a hint, and it is up to consumers that
are requesting focus to honor this property. This is typically honored
for mouse operations, but not keyboard operations. For example, look
and feels could verify this property is true before requesting focus
during a mouse operation. This would often times be used if you did
not want a mouse press on a JComponent to steal focus,
but did want the JComponent to be traversable via the
keyboard. If you do not want this JComponent focusable at
all, use the setFocusable method instead.


Please see

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

Params:
  • requestFocusEnabled – indicates whether you want this
       JComponent to be focusable or not
See Also:
/**
     * Provides a hint as to whether or not this <code>JComponent</code>
     * should get focus. This is only a hint, and it is up to consumers that
     * are requesting focus to honor this property. This is typically honored
     * for mouse operations, but not keyboard operations. For example, look
     * and feels could verify this property is true before requesting focus
     * during a mouse operation. This would often times be used if you did
     * not want a mouse press on a <code>JComponent</code> to steal focus,
     * but did want the <code>JComponent</code> to be traversable via the
     * keyboard. If you do not want this <code>JComponent</code> focusable at
     * all, use the <code>setFocusable</code> method instead.
     * <p>
     * Please see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>,
     * for more information.
     *
     * @param requestFocusEnabled indicates whether you want this
     *        <code>JComponent</code> to be focusable or not
     * @see <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
     * @see java.awt.Component#setFocusable
     */
    public void setRequestFocusEnabled(boolean requestFocusEnabled) {
        setFlag(REQUEST_FOCUS_DISABLED, !requestFocusEnabled);
    }

    
Returns true if this JComponent should
get focus; otherwise returns false.


Please see

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

See Also:
Returns:true if this component should get focus,
    otherwise returns false
/**
     * Returns <code>true</code> if this <code>JComponent</code> should
     * get focus; otherwise returns <code>false</code>.
     * <p>
     * Please see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>,
     * for more information.
     *
     * @return <code>true</code> if this component should get focus,
     *     otherwise returns <code>false</code>
     * @see #setRequestFocusEnabled
     * @see <a href="../../java/awt/doc-files/FocusSpec.html">Focus
     *      Specification</a>
     * @see java.awt.Component#isFocusable
     */
    public boolean isRequestFocusEnabled() {
        return !getFlag(REQUEST_FOCUS_DISABLED);
    }

    
Requests that this Component gets the input focus. Refer to 
Component.requestFocus() for a complete description of this method. 
 Note that the use of this method is discouraged because its behavior is platform dependent. Instead we recommend the use of requestFocusInWindow(). If you would like more information on focus, see 
How to Use the Focus Subsystem,
a section in The Java Tutorial.

See Also:
Since:1.4
/**
     * Requests that this <code>Component</code> gets the input focus.
     * Refer to {@link java.awt.Component#requestFocus()
     * Component.requestFocus()} for a complete description of
     * this method.
     * <p>
     * Note that the use of this method is discouraged because
     * its behavior is platform dependent. Instead we recommend the
     * use of {@link #requestFocusInWindow() requestFocusInWindow()}.
     * If you would like more information on focus, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     *
     * @see java.awt.Component#requestFocusInWindow()
     * @see java.awt.Component#requestFocusInWindow(boolean)
     * @since 1.4
     */
    public void requestFocus() {
        super.requestFocus();
    }

    
Requests that this Component gets the input focus. Refer to 
Component.requestFocus(boolean) for a complete description of this method. 
 Note that the use of this method is discouraged because its behavior is platform dependent. Instead we recommend the use of 
requestFocusInWindow(boolean). If you would like more information on focus, see 
How to Use the Focus Subsystem,
a section in The Java Tutorial.

Params:
  • temporary – boolean indicating if the focus change is temporary
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</code> gets the input focus.
     * Refer to {@link java.awt.Component#requestFocus(boolean)
     * Component.requestFocus(boolean)} for a complete description of
     * this method.
     * <p>
     * Note that the use of this method is discouraged because
     * its behavior is platform dependent. Instead we recommend the
     * use of {@link #requestFocusInWindow(boolean)
     * requestFocusInWindow(boolean)}.
     * If you would like more information on focus, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     *
     * @param temporary boolean indicating if the focus change is temporary
     * @return <code>false</code> if the focus change request is guaranteed to
     *         fail; <code>true</code> if it is likely to succeed
     * @see java.awt.Component#requestFocusInWindow()
     * @see java.awt.Component#requestFocusInWindow(boolean)
     * @since 1.4
     */
    public boolean requestFocus(boolean temporary) {
        return super.requestFocus(temporary);
    }

    
Requests that this Component gets the input focus. Refer to 
Component.requestFocusInWindow() for a complete description of this method. 

If you would like more information on focus, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.

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</code> gets the input focus.
     * Refer to {@link java.awt.Component#requestFocusInWindow()
     * Component.requestFocusInWindow()} for a complete description of
     * this method.
     * <p>
     * If you would like more information on focus, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     *
     * @return <code>false</code> if the focus change request is guaranteed to
     *         fail; <code>true</code> if it is likely to succeed
     * @see java.awt.Component#requestFocusInWindow()
     * @see java.awt.Component#requestFocusInWindow(boolean)
     * @since 1.4
     */
    public boolean requestFocusInWindow() {
        return super.requestFocusInWindow();
    }

    
Requests that this Component gets the input focus. Refer to 
Component.requestFocusInWindow(boolean) for a complete description of this method. 

If you would like more information on focus, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.

Params:
  • temporary – boolean indicating if the focus change is temporary
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</code> gets the input focus.
     * Refer to {@link java.awt.Component#requestFocusInWindow(boolean)
     * Component.requestFocusInWindow(boolean)} for a complete description of
     * this method.
     * <p>
     * If you would like more information on focus, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     *
     * @param temporary boolean indicating if the focus change is temporary
     * @return <code>false</code> if the focus change request is guaranteed to
     *         fail; <code>true</code> if it is likely to succeed
     * @see java.awt.Component#requestFocusInWindow()
     * @see java.awt.Component#requestFocusInWindow(boolean)
     * @since 1.4
     */
    protected boolean requestFocusInWindow(boolean temporary) {
        return super.requestFocusInWindow(temporary);
    }

    
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, visible, and focusable for the request to be
granted.


This method is intended for use by focus implementations. Client code
should not use this method; instead, it should use
requestFocusInWindow().

See Also:
  • requestFocusInWindow()
/**
     * 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, visible, and focusable for the request to be
     * granted.
     * <p>
     * This method is intended for use by focus implementations. Client code
     * should not use this method; instead, it should use
     * <code>requestFocusInWindow()</code>.
     *
     * @see #requestFocusInWindow()
     */
    public void grabFocus() {
        requestFocus();
    }

    
Sets the value to indicate whether input verifier for the
current focus owner will be called before this component requests
focus. The default is true. Set to false on components such as a
Cancel button or a scrollbar, which should activate even if the
input in the current focus owner is not "passed" by the input
verifier for that component.

Params:
  • verifyInputWhenFocusTarget – value for the
       verifyInputWhenFocusTarget property
See Also:
Since:1.3
/**
     * Sets the value to indicate whether input verifier for the
     * current focus owner will be called before this component requests
     * focus. The default is true. Set to false on components such as a
     * Cancel button or a scrollbar, which should activate even if the
     * input in the current focus owner is not "passed" by the input
     * verifier for that component.
     *
     * @param verifyInputWhenFocusTarget value for the
     *        <code>verifyInputWhenFocusTarget</code> property
     * @see InputVerifier
     * @see #setInputVerifier
     * @see #getInputVerifier
     * @see #getVerifyInputWhenFocusTarget
     *
     * @since 1.3
     */
    @BeanProperty(description
            = "Whether the Component verifies input before accepting focus.")
    public void setVerifyInputWhenFocusTarget(boolean
                                              verifyInputWhenFocusTarget) {
        boolean oldVerifyInputWhenFocusTarget =
            this.verifyInputWhenFocusTarget;
        this.verifyInputWhenFocusTarget = verifyInputWhenFocusTarget;
        firePropertyChange("verifyInputWhenFocusTarget",
                           oldVerifyInputWhenFocusTarget,
                           verifyInputWhenFocusTarget);
    }

    
Returns the value that indicates whether the input verifier for the
current focus owner will be called before this component requests
focus.

See Also:
Returns:value of the verifyInputWhenFocusTarget property
Since:1.3
/**
     * Returns the value that indicates whether the input verifier for the
     * current focus owner will be called before this component requests
     * focus.
     *
     * @return value of the <code>verifyInputWhenFocusTarget</code> property
     *
     * @see InputVerifier
     * @see #setInputVerifier
     * @see #getInputVerifier
     * @see #setVerifyInputWhenFocusTarget
     *
     * @since 1.3
     */
    public boolean getVerifyInputWhenFocusTarget() {
        return verifyInputWhenFocusTarget;
    }


    
Gets the FontMetrics for the specified Font.

Params:
  • font – the font for which font metrics is to be
         obtained
Throws:
Returns:the font metrics for font
Since:1.5
/**
     * Gets the <code>FontMetrics</code> for the specified <code>Font</code>.
     *
     * @param font the font for which font metrics is to be
     *          obtained
     * @return the font metrics for <code>font</code>
     * @throws NullPointerException if <code>font</code> is null
     * @since 1.5
     */
    public FontMetrics getFontMetrics(Font font) {
        return SwingUtilities2.getFontMetrics(this, font);
    }


    
Sets the preferred size of this component.
If preferredSize is null, the UI will
be asked for the preferred size.

/**
     * Sets the preferred size of this component.
     * If <code>preferredSize</code> is <code>null</code>, the UI will
     * be asked for the preferred size.
     */
    @BeanProperty(preferred = true, description
            = "The preferred size of the component.")
    public void setPreferredSize(Dimension preferredSize) {
        super.setPreferredSize(preferredSize);
    }


    
If the preferredSize has been set to a
non-null value just returns it.
If the UI delegate's getPreferredSize
method returns a non null value then return that;
otherwise defer to the component's layout manager.

See Also:
Returns:the value of the preferredSize property
/**
     * If the <code>preferredSize</code> has been set to a
     * non-<code>null</code> value just returns it.
     * If the UI delegate's <code>getPreferredSize</code>
     * method returns a non <code>null</code> value then return that;
     * otherwise defer to the component's layout manager.
     *
     * @return the value of the <code>preferredSize</code> property
     * @see #setPreferredSize
     * @see ComponentUI
     */
    @Transient
    public Dimension getPreferredSize() {
        if (isPreferredSizeSet()) {
            return super.getPreferredSize();
        }
        Dimension size = null;
        if (ui != null) {
            size = ui.getPreferredSize(this);
        }
        return (size != null) ? size : super.getPreferredSize();
    }


    
Sets the maximum size of this component to a constant
value.  Subsequent calls to getMaximumSize will always
return this value; the component's UI will not be asked
to compute it.  Setting the maximum size to null
restores the default behavior.

Params:
  • maximumSize – a Dimension containing the
         desired maximum allowable size
See Also:
/**
     * Sets the maximum size of this component to a constant
     * value.  Subsequent calls to <code>getMaximumSize</code> will always
     * return this value; the component's UI will not be asked
     * to compute it.  Setting the maximum size to <code>null</code>
     * restores the default behavior.
     *
     * @param maximumSize a <code>Dimension</code> containing the
     *          desired maximum allowable size
     * @see #getMaximumSize
     */
    @BeanProperty(description
            = "The maximum size of the component.")
    public void setMaximumSize(Dimension maximumSize) {
        super.setMaximumSize(maximumSize);
    }


    
If the maximum size has been set to a non-null value
just returns it.  If the UI delegate's getMaximumSize
method returns a non-null value then return that;
otherwise defer to the component's layout manager.

See Also:
Returns:the value of the maximumSize property
/**
     * If the maximum size has been set to a non-<code>null</code> value
     * just returns it.  If the UI delegate's <code>getMaximumSize</code>
     * method returns a non-<code>null</code> value then return that;
     * otherwise defer to the component's layout manager.
     *
     * @return the value of the <code>maximumSize</code> property
     * @see #setMaximumSize
     * @see ComponentUI
     */
    @Transient
    public Dimension getMaximumSize() {
        if (isMaximumSizeSet()) {
            return super.getMaximumSize();
        }
        Dimension size = null;
        if (ui != null) {
            size = ui.getMaximumSize(this);
        }
        return (size != null) ? size : super.getMaximumSize();
    }


    
Sets the minimum size of this component to a constant
value.  Subsequent calls to getMinimumSize will always
return this value; the component's UI will not be asked
to compute it.  Setting the minimum size to null
restores the default behavior.

Params:
  • minimumSize – the new minimum size of this component
See Also:
/**
     * Sets the minimum size of this component to a constant
     * value.  Subsequent calls to <code>getMinimumSize</code> will always
     * return this value; the component's UI will not be asked
     * to compute it.  Setting the minimum size to <code>null</code>
     * restores the default behavior.
     *
     * @param minimumSize the new minimum size of this component
     * @see #getMinimumSize
     */
    @BeanProperty(description
            = "The minimum size of the component.")
    public void setMinimumSize(Dimension minimumSize) {
        super.setMinimumSize(minimumSize);
    }

    
If the minimum size has been set to a non-null value
just returns it.  If the UI delegate's getMinimumSize
method returns a non-null value then return that; otherwise
defer to the component's layout manager.

See Also:
Returns:the value of the minimumSize property
/**
     * If the minimum size has been set to a non-<code>null</code> value
     * just returns it.  If the UI delegate's <code>getMinimumSize</code>
     * method returns a non-<code>null</code> value then return that; otherwise
     * defer to the component's layout manager.
     *
     * @return the value of the <code>minimumSize</code> property
     * @see #setMinimumSize
     * @see ComponentUI
     */
    @Transient
    public Dimension getMinimumSize() {
        if (isMinimumSizeSet()) {
            return super.getMinimumSize();
        }
        Dimension size = null;
        if (ui != null) {
            size = ui.getMinimumSize(this);
        }
        return (size != null) ? size : super.getMinimumSize();
    }

    
Gives the UI delegate an opportunity to define the precise
shape of this component for the sake of mouse processing.

See Also:
Returns:true if this component logically contains x,y
/**
     * Gives the UI delegate an opportunity to define the precise
     * shape of this component for the sake of mouse processing.
     *
     * @return true if this component logically contains x,y
     * @see java.awt.Component#contains(int, int)
     * @see ComponentUI
     */
    public boolean contains(int x, int y) {
        return (ui != null) ? ui.contains(this, x, y) : super.contains(x, y);
    }

    
Sets the border of this component.  The Border object is
responsible for defining the insets for the component
(overriding any insets set directly on the component) and
for optionally rendering any border decorations within the
bounds of those insets.  Borders should be used (rather
than insets) for creating both decorative and non-decorative
(such as margins and padding) regions for a swing component.
Compound borders can be used to nest multiple borders within a
single component.


Although technically you can set the border on any object
that inherits from JComponent, the look and
feel implementation of many standard Swing components
doesn't work well with user-set borders.  In general,
when you want to set a border on a standard Swing
component other than JPanel or JLabel,
we recommend that you put the component in a JPanel
and set the border on the JPanel.


This is a bound property.

Params:
  • border – the border to be rendered for this component
See Also:
/**
     * Sets the border of this component.  The <code>Border</code> object is
     * responsible for defining the insets for the component
     * (overriding any insets set directly on the component) and
     * for optionally rendering any border decorations within the
     * bounds of those insets.  Borders should be used (rather
     * than insets) for creating both decorative and non-decorative
     * (such as margins and padding) regions for a swing component.
     * Compound borders can be used to nest multiple borders within a
     * single component.
     * <p>
     * Although technically you can set the border on any object
     * that inherits from <code>JComponent</code>, the look and
     * feel implementation of many standard Swing components
     * doesn't work well with user-set borders.  In general,
     * when you want to set a border on a standard Swing
     * component other than <code>JPanel</code> or <code>JLabel</code>,
     * we recommend that you put the component in a <code>JPanel</code>
     * and set the border on the <code>JPanel</code>.
     * <p>
     * This is a bound property.
     *
     * @param border the border to be rendered for this component
     * @see Border
     * @see CompoundBorder
     */
    @BeanProperty(preferred = true, visualUpdate = true, description
            = "The component's border.")
    public void setBorder(Border border) {
        Border         oldBorder = this.border;

        this.border = border;
        firePropertyChange("border", oldBorder, border);
        if (border != oldBorder) {
            if (border == null || oldBorder == null ||
                !(border.getBorderInsets(this).equals(oldBorder.getBorderInsets(this)))) {
                revalidate();
            }
            repaint();
        }
    }

    
Returns the border of this component or null if no
border is currently set.

See Also:
Returns:the border object for this component
/**
     * Returns the border of this component or <code>null</code> if no
     * border is currently set.
     *
     * @return the border object for this component
     * @see #setBorder
     */
    public Border getBorder() {
        return border;
    }

    
If a border has been set on this component, returns the
border's insets; otherwise calls super.getInsets.

See Also:
Returns:the value of the insets property
/**
     * If a border has been set on this component, returns the
     * border's insets; otherwise calls <code>super.getInsets</code>.
     *
     * @return the value of the insets property
     * @see #setBorder
     */
    @BeanProperty(expert = true)
    public Insets getInsets() {
        if (border != null) {
            return border.getBorderInsets(this);
        }
        return super.getInsets();
    }

    
Returns an Insets object containing this component's inset
values.  The passed-in Insets object will be reused
if possible.
Calling methods cannot assume that the same object will be returned,
however.  All existing values within this object are overwritten.
If insets is null, this will allocate a new one.

Params:
  • insets – the Insets object, which can be reused
See Also:
Returns:the Insets object
/**
     * Returns an <code>Insets</code> object containing this component's inset
     * values.  The passed-in <code>Insets</code> object will be reused
     * if possible.
     * Calling methods cannot assume that the same object will be returned,
     * however.  All existing values within this object are overwritten.
     * If <code>insets</code> is null, this will allocate a new one.
     *
     * @param insets the <code>Insets</code> object, which can be reused
     * @return the <code>Insets</code> object
     * @see #getInsets
     */
    public Insets getInsets(Insets insets) {
        if (insets == null) {
            insets = new Insets(0, 0, 0, 0);
        }
        if (border != null) {
            if (border instanceof AbstractBorder) {
                return ((AbstractBorder)border).getBorderInsets(this, insets);
            } else {
                // Can't reuse border insets because the Border interface
                // can't be enhanced.
                return border.getBorderInsets(this);
            }
        } else {
            // super.getInsets() always returns an Insets object with
            // all of its value zeroed.  No need for a new object here.
            insets.left = insets.top = insets.right = insets.bottom = 0;
            return insets;
        }
    }

    
Overrides Container.getAlignmentY to return
the vertical alignment.

See Also:
Returns:the value of the alignmentY property
/**
     * Overrides <code>Container.getAlignmentY</code> to return
     * the vertical alignment.
     *
     * @return the value of the <code>alignmentY</code> property
     * @see #setAlignmentY
     * @see java.awt.Component#getAlignmentY
     */
    public float getAlignmentY() {
        if (isAlignmentYSet) {
            return alignmentY;
        }
        return super.getAlignmentY();
    }

    
Sets the vertical alignment.

Params:
  • alignmentY –  the new vertical alignment
See Also:
/**
     * Sets the vertical alignment.
     *
     * @param alignmentY  the new vertical alignment
     * @see #getAlignmentY
     */
    @BeanProperty(description
            = "The preferred vertical alignment of the component.")
    public void setAlignmentY(float alignmentY) {
        this.alignmentY = validateAlignment(alignmentY);
        isAlignmentYSet = true;
    }


    
Overrides Container.getAlignmentX to return
the horizontal alignment.

See Also:
Returns:the value of the alignmentX property
/**
     * Overrides <code>Container.getAlignmentX</code> to return
     * the horizontal alignment.
     *
     * @return the value of the <code>alignmentX</code> property
     * @see #setAlignmentX
     * @see java.awt.Component#getAlignmentX
     */
    public float getAlignmentX() {
        if (isAlignmentXSet) {
            return alignmentX;
        }
        return super.getAlignmentX();
    }

    
Sets the horizontal alignment.

Params:
  • alignmentX –  the new horizontal alignment
See Also:
/**
     * Sets the horizontal alignment.
     *
     * @param alignmentX  the new horizontal alignment
     * @see #getAlignmentX
     */
    @BeanProperty(description
            = "The preferred horizontal alignment of the component.")
    public void setAlignmentX(float alignmentX) {
        this.alignmentX = validateAlignment(alignmentX);
        isAlignmentXSet = true;
    }

    private float validateAlignment(float alignment) {
        return alignment > 1.0f ? 1.0f : alignment < 0.0f ? 0.0f : alignment;
    }

    
Sets the input verifier for this component.

Params:
  • inputVerifier – the new input verifier
See Also:
Since:1.3
/**
     * Sets the input verifier for this component.
     *
     * @param inputVerifier the new input verifier
     * @since 1.3
     * @see InputVerifier
     */
    @BeanProperty(description
            = "The component's input verifier.")
    public void setInputVerifier(InputVerifier inputVerifier) {
        InputVerifier oldInputVerifier = (InputVerifier)getClientProperty(
                                         JComponent_INPUT_VERIFIER);
        putClientProperty(JComponent_INPUT_VERIFIER, inputVerifier);
        firePropertyChange("inputVerifier", oldInputVerifier, inputVerifier);
    }

    
Returns the input verifier for this component.

See Also:
Returns:the inputVerifier property
Since:1.3
/**
     * Returns the input verifier for this component.
     *
     * @return the <code>inputVerifier</code> property
     * @since 1.3
     * @see InputVerifier
     */
    public InputVerifier getInputVerifier() {
        return (InputVerifier)getClientProperty(JComponent_INPUT_VERIFIER);
    }

    
Returns this component's graphics context, which lets you draw
on a component. Use this method to get a Graphics object and
then invoke operations on that object to draw on the component.

Returns:this components graphics context
/**
     * Returns this component's graphics context, which lets you draw
     * on a component. Use this method to get a <code>Graphics</code> object and
     * then invoke operations on that object to draw on the component.
     * @return this components graphics context
     */
    @BeanProperty(bound = false)
    public Graphics getGraphics() {
        if (DEBUG_GRAPHICS_LOADED && shouldDebugGraphics() != 0) {
            DebugGraphics graphics = new DebugGraphics(super.getGraphics(),
                                                       this);
            return graphics;
        }
        return super.getGraphics();
    }


    
Enables or disables diagnostic information about every graphics
operation performed within the component or one of its children.

Params:
  • debugOptions –  determines how the component should display
        the information;  one of the following options:

      

    • DebugGraphics.LOG_OPTION - causes a text message to be printed.

    • DebugGraphics.FLASH_OPTION - causes the drawing to flash several
times.

    • DebugGraphics.BUFFERED_OPTION - creates an
        ExternalWindow that displays the operations
        performed on the View's offscreen buffer.

    • DebugGraphics.NONE_OPTION disables debugging.

    • A value of 0 causes no changes to the debugging options.

    
debugOptions is bitwise OR'd into the current value
/** Enables or disables diagnostic information about every graphics
      * operation performed within the component or one of its children.
      *
      * @param debugOptions  determines how the component should display
      *         the information;  one of the following options:
      * <ul>
      * <li>DebugGraphics.LOG_OPTION - causes a text message to be printed.
      * <li>DebugGraphics.FLASH_OPTION - causes the drawing to flash several
      * times.
      * <li>DebugGraphics.BUFFERED_OPTION - creates an
      *         <code>ExternalWindow</code> that displays the operations
      *         performed on the View's offscreen buffer.
      * <li>DebugGraphics.NONE_OPTION disables debugging.
      * <li>A value of 0 causes no changes to the debugging options.
      * </ul>
      * <code>debugOptions</code> is bitwise OR'd into the current value
      */
    @BeanProperty(bound = false, preferred = true, enumerationValues = {
            "DebugGraphics.NONE_OPTION",
            "DebugGraphics.LOG_OPTION",
            "DebugGraphics.FLASH_OPTION",
            "DebugGraphics.BUFFERED_OPTION"}, description
            = "Diagnostic options for graphics operations.")
    public void setDebugGraphicsOptions(int debugOptions) {
        DebugGraphics.setDebugOptions(this, debugOptions);
    }

    
Returns the state of graphics debugging.

See Also:
Returns:a bitwise OR'd flag of zero or more of the following options:

    

  • DebugGraphics.LOG_OPTION - causes a text message to be printed.

  • DebugGraphics.FLASH_OPTION - causes the drawing to flash several
times.

  • DebugGraphics.BUFFERED_OPTION - creates an
        ExternalWindow that displays the operations
        performed on the View's offscreen buffer.

  • DebugGraphics.NONE_OPTION disables debugging.

  • A value of 0 causes no changes to the debugging options.

/** Returns the state of graphics debugging.
      *
      * @return a bitwise OR'd flag of zero or more of the following options:
      * <ul>
      * <li>DebugGraphics.LOG_OPTION - causes a text message to be printed.
      * <li>DebugGraphics.FLASH_OPTION - causes the drawing to flash several
      * times.
      * <li>DebugGraphics.BUFFERED_OPTION - creates an
      *         <code>ExternalWindow</code> that displays the operations
      *         performed on the View's offscreen buffer.
      * <li>DebugGraphics.NONE_OPTION disables debugging.
      * <li>A value of 0 causes no changes to the debugging options.
      * </ul>
      * @see #setDebugGraphicsOptions
      */
    public int getDebugGraphicsOptions() {
        return DebugGraphics.getDebugOptions(this);
    }


    
Returns true if debug information is enabled for this
JComponent or one of its parents.

/**
     * Returns true if debug information is enabled for this
     * <code>JComponent</code> or one of its parents.
     */
    int shouldDebugGraphics() {
        return DebugGraphics.shouldComponentDebug(this);
    }

    
This method is now obsolete, please use a combination of
getActionMap() and getInputMap() for
similar behavior. For example, to bind the KeyStroke
aKeyStroke to the Action anAction
now use:

  component.getInputMap().put(aKeyStroke, aCommand);
  component.getActionMap().put(aCommmand, anAction);


The above assumes you want the binding to be applicable for
WHEN_FOCUSED. To register bindings for other focus
states use the getInputMap method that takes an integer.


Register a new keyboard action.
anAction will be invoked if a key event matching
aKeyStroke occurs and aCondition is verified.
The KeyStroke object defines a
particular combination of a keyboard key and one or more modifiers
(alt, shift, ctrl, meta).


The aCommand will be set in the delivered event if
specified.


The aCondition can be one of:





WHEN_FOCUSED

The action will be invoked only when the keystroke occurs
    while the component has the focus.

WHEN_IN_FOCUSED_WINDOW

The action will be invoked when the keystroke occurs while
    the component has the focus or if the component is in the
    window that has the focus. Note that the component need not
    be an immediate descendent of the window -- it can be
    anywhere in the window's containment hierarchy. In other
    words, whenever any component in the window has the focus,
    the action registered with this component is invoked.

WHEN_ANCESTOR_OF_FOCUSED_COMPONENT

The action will be invoked when the keystroke occurs while the
    component has the focus or if the component is an ancestor of
    the component that has the focus.






The combination of keystrokes and conditions lets you define high
level (semantic) action events for a specified keystroke+modifier
combination (using the KeyStroke class) and direct to a parent or
child of a component that has the focus, or to the component itself.
In other words, in any hierarchical structure of components, an
arbitrary key-combination can be immediately directed to the
appropriate component in the hierarchy, and cause a specific method
to be invoked (usually by way of adapter objects).


If an action has already been registered for the receiving
container, with the same charCode and the same modifiers,
anAction will replace the action.

Params:
  • anAction –  the Action to be registered
  • aCommand –  the command to be set in the delivered event
  • aKeyStroke – the KeyStroke to bind to the action
  • aCondition – the condition that needs to be met, see above
See Also:
/**
     * This method is now obsolete, please use a combination of
     * <code>getActionMap()</code> and <code>getInputMap()</code> for
     * similar behavior. For example, to bind the <code>KeyStroke</code>
     * <code>aKeyStroke</code> to the <code>Action</code> <code>anAction</code>
     * now use:
     * <pre>
     *   component.getInputMap().put(aKeyStroke, aCommand);
     *   component.getActionMap().put(aCommmand, anAction);
     * </pre>
     * The above assumes you want the binding to be applicable for
     * <code>WHEN_FOCUSED</code>. To register bindings for other focus
     * states use the <code>getInputMap</code> method that takes an integer.
     * <p>
     * Register a new keyboard action.
     * <code>anAction</code> will be invoked if a key event matching
     * <code>aKeyStroke</code> occurs and <code>aCondition</code> is verified.
     * The <code>KeyStroke</code> object defines a
     * particular combination of a keyboard key and one or more modifiers
     * (alt, shift, ctrl, meta).
     * <p>
     * The <code>aCommand</code> will be set in the delivered event if
     * specified.
     * <p>
     * The <code>aCondition</code> can be one of:
     * <blockquote>
     * <DL>
     * <DT>WHEN_FOCUSED
     * <DD>The action will be invoked only when the keystroke occurs
     *     while the component has the focus.
     * <DT>WHEN_IN_FOCUSED_WINDOW
     * <DD>The action will be invoked when the keystroke occurs while
     *     the component has the focus or if the component is in the
     *     window that has the focus. Note that the component need not
     *     be an immediate descendent of the window -- it can be
     *     anywhere in the window's containment hierarchy. In other
     *     words, whenever <em>any</em> component in the window has the focus,
     *     the action registered with this component is invoked.
     * <DT>WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
     * <DD>The action will be invoked when the keystroke occurs while the
     *     component has the focus or if the component is an ancestor of
     *     the component that has the focus.
     * </DL>
     * </blockquote>
     * <p>
     * The combination of keystrokes and conditions lets you define high
     * level (semantic) action events for a specified keystroke+modifier
     * combination (using the KeyStroke class) and direct to a parent or
     * child of a component that has the focus, or to the component itself.
     * In other words, in any hierarchical structure of components, an
     * arbitrary key-combination can be immediately directed to the
     * appropriate component in the hierarchy, and cause a specific method
     * to be invoked (usually by way of adapter objects).
     * <p>
     * If an action has already been registered for the receiving
     * container, with the same charCode and the same modifiers,
     * <code>anAction</code> will replace the action.
     *
     * @param anAction  the <code>Action</code> to be registered
     * @param aCommand  the command to be set in the delivered event
     * @param aKeyStroke the <code>KeyStroke</code> to bind to the action
     * @param aCondition the condition that needs to be met, see above
     * @see KeyStroke
     */
    public void registerKeyboardAction(ActionListener anAction,String aCommand,KeyStroke aKeyStroke,int aCondition) {

        InputMap inputMap = getInputMap(aCondition, true);

        if (inputMap != null) {
            ActionMap actionMap = getActionMap(true);
            ActionStandin action = new ActionStandin(anAction, aCommand);
            inputMap.put(aKeyStroke, action);
            if (actionMap != null) {
                actionMap.put(action, action);
            }
        }
    }

    
Registers any bound WHEN_IN_FOCUSED_WINDOW actions with
the KeyboardManager. If onlyIfNew
is true only actions that haven't been registered are pushed
to the KeyboardManager;
otherwise all actions are pushed to the KeyboardManager.

Params:
  • onlyIfNew –  if true, only actions that haven't been registered
         are pushed to the KeyboardManager
/**
     * Registers any bound <code>WHEN_IN_FOCUSED_WINDOW</code> actions with
     * the <code>KeyboardManager</code>. If <code>onlyIfNew</code>
     * is true only actions that haven't been registered are pushed
     * to the <code>KeyboardManager</code>;
     * otherwise all actions are pushed to the <code>KeyboardManager</code>.
     *
     * @param onlyIfNew  if true, only actions that haven't been registered
     *          are pushed to the <code>KeyboardManager</code>
     */
    private void registerWithKeyboardManager(boolean onlyIfNew) {
        InputMap inputMap = getInputMap(WHEN_IN_FOCUSED_WINDOW, false);
        KeyStroke[] strokes;
        @SuppressWarnings("unchecked")
        Hashtable<KeyStroke, KeyStroke> registered =
                (Hashtable<KeyStroke, KeyStroke>)getClientProperty
                                (WHEN_IN_FOCUSED_WINDOW_BINDINGS);

        if (inputMap != null) {
            // Push any new KeyStrokes to the KeyboardManager.
            strokes = inputMap.allKeys();
            if (strokes != null) {
                for (int counter = strokes.length - 1; counter >= 0;
                     counter--) {
                    if (!onlyIfNew || registered == null ||
                        registered.get(strokes[counter]) == null) {
                        registerWithKeyboardManager(strokes[counter]);
                    }
                    if (registered != null) {
                        registered.remove(strokes[counter]);
                    }
                }
            }
        }
        else {
            strokes = null;
        }
        // Remove any old ones.
        if (registered != null && registered.size() > 0) {
            Enumeration<KeyStroke> keys = registered.keys();

            while (keys.hasMoreElements()) {
                KeyStroke ks = keys.nextElement();
                unregisterWithKeyboardManager(ks);
            }
            registered.clear();
        }
        // Updated the registered Hashtable.
        if (strokes != null && strokes.length > 0) {
            if (registered == null) {
                registered = new Hashtable<KeyStroke, KeyStroke>(strokes.length);
                putClientProperty(WHEN_IN_FOCUSED_WINDOW_BINDINGS, registered);
            }
            for (int counter = strokes.length - 1; counter >= 0; counter--) {
                registered.put(strokes[counter], strokes[counter]);
            }
        }
        else {
            putClientProperty(WHEN_IN_FOCUSED_WINDOW_BINDINGS, null);
        }
    }

    
Unregisters all the previously registered
WHEN_IN_FOCUSED_WINDOW KeyStroke bindings.

/**
     * Unregisters all the previously registered
     * <code>WHEN_IN_FOCUSED_WINDOW</code> <code>KeyStroke</code> bindings.
     */
    private void unregisterWithKeyboardManager() {
        @SuppressWarnings("unchecked")
        Hashtable<KeyStroke, KeyStroke> registered =
                (Hashtable<KeyStroke, KeyStroke>)getClientProperty
                                (WHEN_IN_FOCUSED_WINDOW_BINDINGS);

        if (registered != null && registered.size() > 0) {
            Enumeration<KeyStroke> keys = registered.keys();

            while (keys.hasMoreElements()) {
                KeyStroke ks = keys.nextElement();
                unregisterWithKeyboardManager(ks);
            }
        }
        putClientProperty(WHEN_IN_FOCUSED_WINDOW_BINDINGS, null);
    }

    
Invoked from ComponentInputMap when its bindings change.
If inputMap is the current windowInputMap
(or a parent of the window InputMap)
the KeyboardManager is notified of the new bindings.

Params:
  • inputMap – the map containing the new bindings
/**
     * Invoked from <code>ComponentInputMap</code> when its bindings change.
     * If <code>inputMap</code> is the current <code>windowInputMap</code>
     * (or a parent of the window <code>InputMap</code>)
     * the <code>KeyboardManager</code> is notified of the new bindings.
     *
     * @param inputMap the map containing the new bindings
     */
    void componentInputMapChanged(ComponentInputMap inputMap) {
        InputMap km = getInputMap(WHEN_IN_FOCUSED_WINDOW, false);

        while (km != inputMap && km != null) {
            km = km.getParent();
        }
        if (km != null) {
            registerWithKeyboardManager(false);
        }
    }

    private void registerWithKeyboardManager(KeyStroke aKeyStroke) {
        KeyboardManager.getCurrentManager().registerKeyStroke(aKeyStroke,this);
    }

    private void unregisterWithKeyboardManager(KeyStroke aKeyStroke) {
        KeyboardManager.getCurrentManager().unregisterKeyStroke(aKeyStroke,
                                                                this);
    }

    
This method is now obsolete, please use a combination of
getActionMap() and getInputMap() for
similar behavior.

Params:
  • anAction –  action to be registered to given keystroke and condition
  • aKeyStroke –  a KeyStroke
  • aCondition –  the condition to be associated with given keystroke
                   and action
See Also:
/**
     * This method is now obsolete, please use a combination of
     * <code>getActionMap()</code> and <code>getInputMap()</code> for
     * similar behavior.
     *
     * @param anAction  action to be registered to given keystroke and condition
     * @param aKeyStroke  a {@code KeyStroke}
     * @param aCondition  the condition to be associated with given keystroke
     *                    and action
     * @see #getActionMap
     * @see #getInputMap(int)
     */
    public void registerKeyboardAction(ActionListener anAction,KeyStroke aKeyStroke,int aCondition) {
        registerKeyboardAction(anAction,null,aKeyStroke,aCondition);
    }

    
This method is now obsolete. To unregister an existing binding
you can either remove the binding from the
ActionMap/InputMap, or place a dummy binding the
InputMap. Removing the binding from the
InputMap allows bindings in parent InputMaps
to be active, whereas putting a dummy binding in the
InputMap effectively disables
the binding from ever happening.


Unregisters a keyboard action.
This will remove the binding from the ActionMap
(if it exists) as well as the InputMaps.

Params:
  • aKeyStroke –  the keystroke for which to unregister its
                   keyboard action
/**
     * This method is now obsolete. To unregister an existing binding
     * you can either remove the binding from the
     * <code>ActionMap/InputMap</code>, or place a dummy binding the
     * <code>InputMap</code>. Removing the binding from the
     * <code>InputMap</code> allows bindings in parent <code>InputMap</code>s
     * to be active, whereas putting a dummy binding in the
     * <code>InputMap</code> effectively disables
     * the binding from ever happening.
     * <p>
     * Unregisters a keyboard action.
     * This will remove the binding from the <code>ActionMap</code>
     * (if it exists) as well as the <code>InputMap</code>s.
     *
     * @param aKeyStroke  the keystroke for which to unregister its
     *                    keyboard action
     */
    public void unregisterKeyboardAction(KeyStroke aKeyStroke) {
        ActionMap am = getActionMap(false);
        for (int counter = 0; counter < 3; counter++) {
            InputMap km = getInputMap(counter, false);
            if (km != null) {
                Object actionID = km.get(aKeyStroke);

                if (am != null && actionID != null) {
                    am.remove(actionID);
                }
                km.remove(aKeyStroke);
            }
        }
    }

    
Returns the KeyStrokes that will initiate
registered actions.

See Also:
Returns:an array of KeyStroke objects
/**
     * Returns the <code>KeyStrokes</code> that will initiate
     * registered actions.
     *
     * @return an array of <code>KeyStroke</code> objects
     * @see #registerKeyboardAction
     */
    @BeanProperty(bound = false)
    public KeyStroke[] getRegisteredKeyStrokes() {
        int[] counts = new int[3];
        KeyStroke[][] strokes = new KeyStroke[3][];

        for (int counter = 0; counter < 3; counter++) {
            InputMap km = getInputMap(counter, false);
            strokes[counter] = (km != null) ? km.allKeys() : null;
            counts[counter] = (strokes[counter] != null) ?
                               strokes[counter].length : 0;
        }
        KeyStroke[] retValue = new KeyStroke[counts[0] + counts[1] +
                                            counts[2]];
        for (int counter = 0, last = 0; counter < 3; counter++) {
            if (counts[counter] > 0) {
                System.arraycopy(strokes[counter], 0, retValue, last,
                                 counts[counter]);
                last += counts[counter];
            }
        }
        return retValue;
    }

    
Returns the condition that determines whether a registered action
occurs in response to the specified keystroke.


For Java 2 platform v1.3, a KeyStroke can be associated
with more than one condition.
For example, 'a' could be bound for the two
conditions WHEN_FOCUSED and
WHEN_IN_FOCUSED_WINDOW condition.

Params:
  • aKeyStroke –  the keystroke for which to request an
                   action-keystroke condition
Returns:the action-keystroke condition
/**
     * Returns the condition that determines whether a registered action
     * occurs in response to the specified keystroke.
     * <p>
     * For Java 2 platform v1.3, a <code>KeyStroke</code> can be associated
     * with more than one condition.
     * For example, 'a' could be bound for the two
     * conditions <code>WHEN_FOCUSED</code> and
     * <code>WHEN_IN_FOCUSED_WINDOW</code> condition.
     *
     * @param aKeyStroke  the keystroke for which to request an
     *                    action-keystroke condition
     * @return the action-keystroke condition
     */
    public int getConditionForKeyStroke(KeyStroke aKeyStroke) {
        for (int counter = 0; counter < 3; counter++) {
            InputMap inputMap = getInputMap(counter, false);
            if (inputMap != null && inputMap.get(aKeyStroke) != null) {
                return counter;
            }
        }
        return UNDEFINED_CONDITION;
    }

    
Returns the object that will perform the action registered for a
given keystroke.

Params:
  • aKeyStroke –  the keystroke for which to return a listener
Returns:the ActionListener
         object invoked when the keystroke occurs
/**
     * Returns the object that will perform the action registered for a
     * given keystroke.
     *
     * @param aKeyStroke  the keystroke for which to return a listener
     * @return the <code>ActionListener</code>
     *          object invoked when the keystroke occurs
     */
    public ActionListener getActionForKeyStroke(KeyStroke aKeyStroke) {
        ActionMap am = getActionMap(false);

        if (am == null) {
            return null;
        }
        for (int counter = 0; counter < 3; counter++) {
            InputMap inputMap = getInputMap(counter, false);
            if (inputMap != null) {
                Object actionBinding = inputMap.get(aKeyStroke);

                if (actionBinding != null) {
                    Action action = am.get(actionBinding);
                    if (action instanceof ActionStandin) {
                        return ((ActionStandin)action).actionListener;
                    }
                    return action;
                }
            }
        }
        return null;
    }

    
Unregisters all the bindings in the first tier InputMaps
and ActionMap. This has the effect of removing any
local bindings, and allowing the bindings defined in parent
InputMap/ActionMaps
(the UI is usually defined in the second tier) to persist.

/**
     * Unregisters all the bindings in the first tier <code>InputMaps</code>
     * and <code>ActionMap</code>. This has the effect of removing any
     * local bindings, and allowing the bindings defined in parent
     * <code>InputMap/ActionMaps</code>
     * (the UI is usually defined in the second tier) to persist.
     */
    public void resetKeyboardActions() {
        // Keys
        for (int counter = 0; counter < 3; counter++) {
            InputMap inputMap = getInputMap(counter, false);

            if (inputMap != null) {
                inputMap.clear();
            }
        }

        // Actions
        ActionMap am = getActionMap(false);

        if (am != null) {
            am.clear();
        }
    }

    
Sets the InputMap to use under the condition
condition to
map. A null value implies you
do not want any bindings to be used, even from the UI. This will
not reinstall the UI InputMap (if there was one).
condition has one of the following values:

    

  • WHEN_IN_FOCUSED_WINDOW

  • WHEN_FOCUSED

  • WHEN_ANCESTOR_OF_FOCUSED_COMPONENT


If condition is WHEN_IN_FOCUSED_WINDOW
and map is not a ComponentInputMap, an
IllegalArgumentException will be thrown.
Similarly, if condition is not one of the values
listed, an IllegalArgumentException will be thrown.

Params:
  • condition – one of the values listed above
  • map –  the InputMap to use for the given condition
Throws:
  • IllegalArgumentException – if condition is
         WHEN_IN_FOCUSED_WINDOW and map
         is not an instance of ComponentInputMap; or
         if condition is not one of the legal values
         specified above
Since:1.3
/**
     * Sets the <code>InputMap</code> to use under the condition
     * <code>condition</code> to
     * <code>map</code>. A <code>null</code> value implies you
     * do not want any bindings to be used, even from the UI. This will
     * not reinstall the UI <code>InputMap</code> (if there was one).
     * <code>condition</code> has one of the following values:
     * <ul>
     * <li><code>WHEN_IN_FOCUSED_WINDOW</code>
     * <li><code>WHEN_FOCUSED</code>
     * <li><code>WHEN_ANCESTOR_OF_FOCUSED_COMPONENT</code>
     * </ul>
     * If <code>condition</code> is <code>WHEN_IN_FOCUSED_WINDOW</code>
     * and <code>map</code> is not a <code>ComponentInputMap</code>, an
     * <code>IllegalArgumentException</code> will be thrown.
     * Similarly, if <code>condition</code> is not one of the values
     * listed, an <code>IllegalArgumentException</code> will be thrown.
     *
     * @param condition one of the values listed above
     * @param map  the <code>InputMap</code> to use for the given condition
     * @exception IllegalArgumentException if <code>condition</code> is
     *          <code>WHEN_IN_FOCUSED_WINDOW</code> and <code>map</code>
     *          is not an instance of <code>ComponentInputMap</code>; or
     *          if <code>condition</code> is not one of the legal values
     *          specified above
     * @since 1.3
     */
    public final void setInputMap(int condition, InputMap map) {
        switch (condition) {
        case WHEN_IN_FOCUSED_WINDOW:
            if (map != null && !(map instanceof ComponentInputMap)) {
                throw new IllegalArgumentException("WHEN_IN_FOCUSED_WINDOW InputMaps must be of type ComponentInputMap");
            }
            windowInputMap = (ComponentInputMap)map;
            setFlag(WIF_INPUTMAP_CREATED, true);
            registerWithKeyboardManager(false);
            break;
        case WHEN_ANCESTOR_OF_FOCUSED_COMPONENT:
            ancestorInputMap = map;
            setFlag(ANCESTOR_INPUTMAP_CREATED, true);
            break;
        case WHEN_FOCUSED:
            focusInputMap = map;
            setFlag(FOCUS_INPUTMAP_CREATED, true);
            break;
        default:
            throw new IllegalArgumentException("condition must be one of JComponent.WHEN_IN_FOCUSED_WINDOW, JComponent.WHEN_FOCUSED or JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT");
        }
    }

    
Returns the InputMap that is used during
condition.

Params:
  • condition – one of WHEN_IN_FOCUSED_WINDOW, WHEN_FOCUSED,
       WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
Returns:the InputMap for the specified
         condition
Since:1.3
/**
     * Returns the <code>InputMap</code> that is used during
     * <code>condition</code>.
     *
     * @param condition one of WHEN_IN_FOCUSED_WINDOW, WHEN_FOCUSED,
     *        WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
     * @return the <code>InputMap</code> for the specified
     *          <code>condition</code>
     * @since 1.3
     */
    public final InputMap getInputMap(int condition) {
        return getInputMap(condition, true);
    }

    
Returns the InputMap that is used when the
component has focus.
This is convenience method for getInputMap(WHEN_FOCUSED).

Returns:the InputMap used when the component has focus
Since:1.3
/**
     * Returns the <code>InputMap</code> that is used when the
     * component has focus.
     * This is convenience method for <code>getInputMap(WHEN_FOCUSED)</code>.
     *
     * @return the <code>InputMap</code> used when the component has focus
     * @since 1.3
     */
    public final InputMap getInputMap() {
        return getInputMap(WHEN_FOCUSED, true);
    }

    
Sets the ActionMap to am. This does not set
the parent of the am to be the ActionMap
from the UI (if there was one), it is up to the caller to have done this.

Params:
  • am –  the new ActionMap
Since:1.3
/**
     * Sets the <code>ActionMap</code> to <code>am</code>. This does not set
     * the parent of the <code>am</code> to be the <code>ActionMap</code>
     * from the UI (if there was one), it is up to the caller to have done this.
     *
     * @param am  the new <code>ActionMap</code>
     * @since 1.3
     */
    public final void setActionMap(ActionMap am) {
        actionMap = am;
        setFlag(ACTIONMAP_CREATED, true);
    }

    
Returns the ActionMap used to determine what
Action to fire for particular KeyStroke
binding. The returned ActionMap, unless otherwise
set, will have the ActionMap from the UI set as the parent.

Returns:the ActionMap containing the key/action bindings
Since:1.3
/**
     * Returns the <code>ActionMap</code> used to determine what
     * <code>Action</code> to fire for particular <code>KeyStroke</code>
     * binding. The returned <code>ActionMap</code>, unless otherwise
     * set, will have the <code>ActionMap</code> from the UI set as the parent.
     *
     * @return the <code>ActionMap</code> containing the key/action bindings
     * @since 1.3
     */
    public final ActionMap getActionMap() {
        return getActionMap(true);
    }

    
Returns the InputMap to use for condition
condition.  If the InputMap hasn't
been created, and create is
true, it will be created.

Params:
  • condition – one of the following values:

      

    • JComponent.FOCUS_INPUTMAP_CREATED

    • JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT

    • JComponent.WHEN_IN_FOCUSED_WINDOW

  • create – if true, create the InputMap if it
         is not already created
Throws:
Returns:the InputMap for the given condition;
         if create is false and the InputMap
         hasn't been created, returns null
/**
     * Returns the <code>InputMap</code> to use for condition
     * <code>condition</code>.  If the <code>InputMap</code> hasn't
     * been created, and <code>create</code> is
     * true, it will be created.
     *
     * @param condition one of the following values:
     * <ul>
     * <li>JComponent.FOCUS_INPUTMAP_CREATED
     * <li>JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
     * <li>JComponent.WHEN_IN_FOCUSED_WINDOW
     * </ul>
     * @param create if true, create the <code>InputMap</code> if it
     *          is not already created
     * @return the <code>InputMap</code> for the given <code>condition</code>;
     *          if <code>create</code> is false and the <code>InputMap</code>
     *          hasn't been created, returns <code>null</code>
     * @exception IllegalArgumentException if <code>condition</code>
     *          is not one of the legal values listed above
     */
    final InputMap getInputMap(int condition, boolean create) {
        switch (condition) {
        case WHEN_FOCUSED:
            if (getFlag(FOCUS_INPUTMAP_CREATED)) {
                return focusInputMap;
            }
            // Hasn't been created yet.
            if (create) {
                InputMap km = new InputMap();
                setInputMap(condition, km);
                return km;
            }
            break;
        case WHEN_ANCESTOR_OF_FOCUSED_COMPONENT:
            if (getFlag(ANCESTOR_INPUTMAP_CREATED)) {
                return ancestorInputMap;
            }
            // Hasn't been created yet.
            if (create) {
                InputMap km = new InputMap();
                setInputMap(condition, km);
                return km;
            }
            break;
        case WHEN_IN_FOCUSED_WINDOW:
            if (getFlag(WIF_INPUTMAP_CREATED)) {
                return windowInputMap;
            }
            // Hasn't been created yet.
            if (create) {
                ComponentInputMap km = new ComponentInputMap(this);
                setInputMap(condition, km);
                return km;
            }
            break;
        default:
            throw new IllegalArgumentException("condition must be one of JComponent.WHEN_IN_FOCUSED_WINDOW, JComponent.WHEN_FOCUSED or JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT");
        }
        return null;
    }

    
Finds and returns the appropriate ActionMap.

Params:
  • create – if true, create the ActionMap if it
         is not already created
Returns:the ActionMap for this component; if the
         create flag is false and there is no
         current ActionMap, returns null
/**
     * Finds and returns the appropriate <code>ActionMap</code>.
     *
     * @param create if true, create the <code>ActionMap</code> if it
     *          is not already created
     * @return the <code>ActionMap</code> for this component; if the
     *          <code>create</code> flag is false and there is no
     *          current <code>ActionMap</code>, returns <code>null</code>
     */
    final ActionMap getActionMap(boolean create) {
        if (getFlag(ACTIONMAP_CREATED)) {
            return actionMap;
        }
        // Hasn't been created.
        if (create) {
            ActionMap am = new ActionMap();
            setActionMap(am);
            return am;
        }
        return null;
    }

    
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.


This method calls into the ComponentUI method of the
same name.  If this component does not have a ComponentUI
-1 will be returned.  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.

Throws:
  • IllegalArgumentException – {@inheritDoc}
See Also:
Since:1.6
/**
     * Returns the baseline.  The baseline is measured from the top of
     * the component.  This method is primarily meant for
     * <code>LayoutManager</code>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</code>s should not align this component on
     * its baseline.
     * <p>
     * This method calls into the <code>ComponentUI</code> method of the
     * same name.  If this component does not have a <code>ComponentUI</code>
     * -1 will be returned.  If a value &gt;= 0 is
     * returned, then the component has a valid baseline for any
     * size &gt;= the minimum size and <code>getBaselineResizeBehavior</code>
     * can be used to determine how the baseline changes with size.
     *
     * @throws IllegalArgumentException {@inheritDoc}
     * @see #getBaselineResizeBehavior
     * @see java.awt.FontMetrics
     * @since 1.6
     */
    public int getBaseline(int width, int height) {
        // check size.
        super.getBaseline(width, height);
        if (ui != null) {
            return ui.getBaseline(this, width, height);
        }
        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.


This method calls into the ComponentUI method of
the same name.  If this component does not have a
ComponentUI
BaselineResizeBehavior.OTHER will be
returned.  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:
  • getBaseline(int, int)
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>
     * This method calls into the <code>ComponentUI</code> method of
     * the same name.  If this component does not have a
     * <code>ComponentUI</code>
     * <code>BaselineResizeBehavior.OTHER</code> will be
     * returned.  Subclasses should
     * never return <code>null</code>; if the baseline can not be
     * calculated return <code>BaselineResizeBehavior.OTHER</code>.  Callers
     * should first ask for the baseline using
     * <code>getBaseline</code> 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</code> even if
     * <code>getBaseline</code> returns a value less than 0.
     *
     * @see #getBaseline(int, int)
     * @since 1.6
     */
    @BeanProperty(bound = false)
    public BaselineResizeBehavior getBaselineResizeBehavior() {
        if (ui != null) {
            return ui.getBaselineResizeBehavior(this);
        }
        return BaselineResizeBehavior.OTHER;
    }

    
In release 1.4, the focus subsystem was rearchitected.
For more information, see

How to Use the Focus Subsystem,
a section in The Java Tutorial.


Requests focus on this JComponent's
FocusTraversalPolicy's default Component.
If this JComponent is a focus cycle root, then its
FocusTraversalPolicy is used. Otherwise, the
FocusTraversalPolicy of this JComponent's
focus-cycle-root ancestor is used.

See Also:
Returns:true if this component can request to get the input focus,
             false if it can not
Deprecated:As of 1.4, replaced by
FocusTraversalPolicy.getDefaultComponent(Container).requestFocus()
/**
     * In release 1.4, the focus subsystem was rearchitected.
     * For more information, see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
     * How to Use the Focus Subsystem</a>,
     * a section in <em>The Java Tutorial</em>.
     * <p>
     * Requests focus on this <code>JComponent</code>'s
     * <code>FocusTraversalPolicy</code>'s default <code>Component</code>.
     * If this <code>JComponent</code> is a focus cycle root, then its
     * <code>FocusTraversalPolicy</code> is used. Otherwise, the
     * <code>FocusTraversalPolicy</code> of this <code>JComponent</code>'s
     * focus-cycle-root ancestor is used.
     *
     * @return true if this component can request to get the input focus,
     *              false if it can not
     * @see java.awt.FocusTraversalPolicy#getDefaultComponent
     * @deprecated As of 1.4, replaced by
     * <code>FocusTraversalPolicy.getDefaultComponent(Container).requestFocus()</code>
     */
    @Deprecated
    public boolean requestDefaultFocus() {
        Container nearestRoot =
            (isFocusCycleRoot()) ? this : getFocusCycleRootAncestor();
        if (nearestRoot == null) {
            return false;
        }
        Component comp = nearestRoot.getFocusTraversalPolicy().
            getDefaultComponent(nearestRoot);
        if (comp != null) {
            comp.requestFocus();
            return true;
        } else {
            return false;
        }
    }

    
Makes the component visible or invisible.
Overrides Component.setVisible.

Params:
  • aFlag –  true to make the component visible; false to
         make it invisible
/**
     * Makes the component visible or invisible.
     * Overrides <code>Component.setVisible</code>.
     *
     * @param aFlag  true to make the component visible; false to
     *          make it invisible
     */
    @BeanProperty(hidden = true, visualUpdate = true)
    public void setVisible(boolean aFlag) {
        if (aFlag != isVisible()) {
            super.setVisible(aFlag);
            if (aFlag) {
                Container parent = getParent();
                if (parent != null) {
                    Rectangle r = getBounds();
                    parent.repaint(r.x, r.y, r.width, r.height);
                }
                revalidate();
            }
        }
    }

    
Sets whether or not this component is enabled.
A component that is enabled may respond to user input,
while a component that is not enabled cannot respond to
user input.  Some components may alter their visual
representation when they are disabled in order to
provide feedback to the user that they cannot take input.

Note: Disabling a component does not disable its children.

Note: Disabling a lightweight component does not prevent it from
receiving MouseEvents.

Params:
  • enabled – true if this component should be enabled, false otherwise
See Also:
/**
     * Sets whether or not this component is enabled.
     * A component that is enabled may respond to user input,
     * while a component that is not enabled cannot respond to
     * user input.  Some components may alter their visual
     * representation when they are disabled in order to
     * provide feedback to the user that they cannot take input.
     * <p>Note: Disabling a component does not disable its children.
     *
     * <p>Note: Disabling a lightweight component does not prevent it from
     * receiving MouseEvents.
     *
     * @param enabled true if this component should be enabled, false otherwise
     * @see java.awt.Component#isEnabled
     * @see java.awt.Component#isLightweight
     */
    @BeanProperty(expert = true, preferred = true, visualUpdate = true, description
            = "The enabled state of the component.")
    public void setEnabled(boolean enabled) {
        boolean oldEnabled = isEnabled();
        super.setEnabled(enabled);
        firePropertyChange("enabled", oldEnabled, enabled);
        if (enabled != oldEnabled) {
            repaint();
        }
    }

    
Sets the foreground color of this component.  It is up to the
look and feel to honor this property, some may choose to ignore
it.

Params:
  • fg –  the desired foreground Color
See Also:
/**
     * Sets the foreground color of this component.  It is up to the
     * look and feel to honor this property, some may choose to ignore
     * it.
     *
     * @param fg  the desired foreground <code>Color</code>
     * @see java.awt.Component#getForeground
     */
    @BeanProperty(preferred = true, visualUpdate = true, description
            = "The foreground color of the component.")
    public void setForeground(Color fg) {
        Color oldFg = getForeground();
        super.setForeground(fg);
        if ((oldFg != null) ? !oldFg.equals(fg) : ((fg != null) && !fg.equals(oldFg))) {
            // foreground already bound in AWT1.2
            repaint();
        }
    }

    
Sets the background color of this component.  The background
color is used only if the component is opaque, and only
by subclasses of JComponent or
ComponentUI implementations.  Direct subclasses of
JComponent must override
paintComponent to honor this property.


It is up to the look and feel to honor this property, some may
choose to ignore it.

Params:
  • bg – the desired background Color
See Also:
/**
     * Sets the background color of this component.  The background
     * color is used only if the component is opaque, and only
     * by subclasses of <code>JComponent</code> or
     * <code>ComponentUI</code> implementations.  Direct subclasses of
     * <code>JComponent</code> must override
     * <code>paintComponent</code> to honor this property.
     * <p>
     * It is up to the look and feel to honor this property, some may
     * choose to ignore it.
     *
     * @param bg the desired background <code>Color</code>
     * @see java.awt.Component#getBackground
     * @see #setOpaque
     */
    @BeanProperty(preferred = true, visualUpdate = true, description
            = "The background color of the component.")
    public void setBackground(Color bg) {
        Color oldBg = getBackground();
        super.setBackground(bg);
        if ((oldBg != null) ? !oldBg.equals(bg) : ((bg != null) && !bg.equals(oldBg))) {
            // background already bound in AWT1.2
            repaint();
        }
    }

    
Sets the font for this component.

Params:
  • font – the desired Font for this component
See Also:
/**
     * Sets the font for this component.
     *
     * @param font the desired <code>Font</code> for this component
     * @see java.awt.Component#getFont
     */
    @BeanProperty(preferred = true, visualUpdate = true, description
            = "The font for the component.")
    public void setFont(Font font) {
        Font oldFont = getFont();
        super.setFont(font);
        // font already bound in AWT1.2
        if (font != oldFont) {
            revalidate();
            repaint();
        }
    }

    
Returns the default locale used to initialize each JComponent's
locale property upon creation.
The default locale has "AppContext" scope so that applets (and
potentially multiple lightweight applications running in a single VM)
can have their own setting. An applet can safely alter its default
locale because it will have no affect on other applets (or the browser).

See Also:
Returns:the default Locale.
Since:1.4
/**
     * Returns the default locale used to initialize each JComponent's
     * locale property upon creation.
     *
     * The default locale has "AppContext" scope so that applets (and
     * potentially multiple lightweight applications running in a single VM)
     * can have their own setting. An applet can safely alter its default
     * locale because it will have no affect on other applets (or the browser).
     *
     * @return the default <code>Locale</code>.
     * @see #setDefaultLocale
     * @see java.awt.Component#getLocale
     * @see #setLocale
     * @since 1.4
     */
    public static Locale getDefaultLocale() {
        Locale l = (Locale) SwingUtilities.appContextGet(defaultLocale);
        if( l == null ) {
            //REMIND(bcb) choosing the default value is more complicated
            //than this.
            l = Locale.getDefault();
            JComponent.setDefaultLocale( l );
        }
        return l;
    }


    
Sets the default locale used to initialize each JComponent's locale
property upon creation.  The initial value is the VM's default locale.
The default locale has "AppContext" scope so that applets (and
potentially multiple lightweight applications running in a single VM)
can have their own setting. An applet can safely alter its default
locale because it will have no affect on other applets (or the browser).

Params:
  • l – the desired default Locale for new components.
See Also:
Since:1.4
/**
     * Sets the default locale used to initialize each JComponent's locale
     * property upon creation.  The initial value is the VM's default locale.
     *
     * The default locale has "AppContext" scope so that applets (and
     * potentially multiple lightweight applications running in a single VM)
     * can have their own setting. An applet can safely alter its default
     * locale because it will have no affect on other applets (or the browser).
     *
     * @param l the desired default <code>Locale</code> for new components.
     * @see #getDefaultLocale
     * @see java.awt.Component#getLocale
     * @see #setLocale
     * @since 1.4
     */
    public static void setDefaultLocale( Locale l ) {
        SwingUtilities.appContextPut(defaultLocale, l);
    }


    
Processes any key events that the component itself
recognizes.  This is called after the focus
manager and any interested listeners have been
given a chance to steal away the event.  This
method is called only if the event has not
yet been consumed.  This method is called prior
to the keyboard UI logic.


This method is implemented to do nothing.  Subclasses would
normally override this method if they process some
key events themselves.  If the event is processed,
it should be consumed.

Params:
  • e – the event to be processed
/**
     * Processes any key events that the component itself
     * recognizes.  This is called after the focus
     * manager and any interested listeners have been
     * given a chance to steal away the event.  This
     * method is called only if the event has not
     * yet been consumed.  This method is called prior
     * to the keyboard UI logic.
     * <p>
     * This method is implemented to do nothing.  Subclasses would
     * normally override this method if they process some
     * key events themselves.  If the event is processed,
     * it should be consumed.
     *
     * @param e the event to be processed
     */
    protected void processComponentKeyEvent(KeyEvent e) {
    }

    
Overrides processKeyEvent to process events. 
/** Overrides <code>processKeyEvent</code> to process events. **/
    protected void processKeyEvent(KeyEvent e) {
      boolean result;
      boolean shouldProcessKey;

      // This gives the key event listeners a crack at the event
      super.processKeyEvent(e);

      // give the component itself a crack at the event
      if (! e.isConsumed()) {
          processComponentKeyEvent(e);
      }

      shouldProcessKey = KeyboardState.shouldProcess(e);

      if(e.isConsumed()) {
        return;
      }

      if (shouldProcessKey && processKeyBindings(e, e.getID() ==
                                                 KeyEvent.KEY_PRESSED)) {
          e.consume();
      }
    }

    
Invoked to process the key bindings for ks as the result
of the KeyEvent e. This obtains
the appropriate InputMap,
gets the binding, gets the action from the ActionMap,
and then (if the action is found and the component
is enabled) invokes notifyAction to notify the action.

Params:
  • ks –  the KeyStroke queried
  • e – the KeyEvent
  • condition – one of the following values:

      

    • JComponent.WHEN_FOCUSED

    • JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT

    • JComponent.WHEN_IN_FOCUSED_WINDOW

  • pressed – true if the key is pressed
Returns:true if there was a binding to an action, and the action
        was enabled
Since:1.3
/**
     * Invoked to process the key bindings for <code>ks</code> as the result
     * of the <code>KeyEvent</code> <code>e</code>. This obtains
     * the appropriate <code>InputMap</code>,
     * gets the binding, gets the action from the <code>ActionMap</code>,
     * and then (if the action is found and the component
     * is enabled) invokes <code>notifyAction</code> to notify the action.
     *
     * @param ks  the <code>KeyStroke</code> queried
     * @param e the <code>KeyEvent</code>
     * @param condition one of the following values:
     * <ul>
     * <li>JComponent.WHEN_FOCUSED
     * <li>JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
     * <li>JComponent.WHEN_IN_FOCUSED_WINDOW
     * </ul>
     * @param pressed true if the key is pressed
     * @return true if there was a binding to an action, and the action
     *         was enabled
     *
     * @since 1.3
     */
    @SuppressWarnings("deprecation")
    protected boolean processKeyBinding(KeyStroke ks, KeyEvent e,
                                        int condition, boolean pressed) {
        InputMap map = getInputMap(condition, false);
        ActionMap am = getActionMap(false);

        if(map != null && am != null && isEnabled()) {
            Object binding = map.get(ks);
            Action action = (binding == null) ? null : am.get(binding);
            if (action != null) {
                return SwingUtilities.notifyAction(action, ks, e, this,
                                                   e.getModifiers());
            }
        }
        return false;
    }

    
This is invoked as the result of a KeyEvent
that was not consumed by the FocusManager,
KeyListeners, or the component. It will first try
WHEN_FOCUSED bindings,
then WHEN_ANCESTOR_OF_FOCUSED_COMPONENT bindings,
and finally WHEN_IN_FOCUSED_WINDOW bindings.

Params:
  • e – the unconsumed KeyEvent
  • pressed – true if the key is pressed
Returns:true if there is a key binding for e
/**
     * This is invoked as the result of a <code>KeyEvent</code>
     * that was not consumed by the <code>FocusManager</code>,
     * <code>KeyListeners</code>, or the component. It will first try
     * <code>WHEN_FOCUSED</code> bindings,
     * then <code>WHEN_ANCESTOR_OF_FOCUSED_COMPONENT</code> bindings,
     * and finally <code>WHEN_IN_FOCUSED_WINDOW</code> bindings.
     *
     * @param e the unconsumed <code>KeyEvent</code>
     * @param pressed true if the key is pressed
     * @return true if there is a key binding for <code>e</code>
     */
    @SuppressWarnings("deprecation")
    boolean processKeyBindings(KeyEvent e, boolean pressed) {
      if (!SwingUtilities.isValidKeyEventForKeyBindings(e)) {
          return false;
      }
      // Get the KeyStroke
      // There may be two keystrokes associated with a low-level key event;
      // in this case a keystroke made of an extended key code has a priority.
      KeyStroke ks;
      KeyStroke ksE = null;

      if (e.getID() == KeyEvent.KEY_TYPED) {
          ks = KeyStroke.getKeyStroke(e.getKeyChar());
      }
      else {
          ks = KeyStroke.getKeyStroke(e.getKeyCode(),e.getModifiers(),
                                    (pressed ? false:true));
          if (e.getKeyCode() != e.getExtendedKeyCode()) {
              ksE = KeyStroke.getKeyStroke(e.getExtendedKeyCode(),e.getModifiers(),
                                    (pressed ? false:true));
          }
      }

      // Do we have a key binding for e?
      // If we have a binding by an extended code, use it.
      // If not, check for regular code binding.
      if(ksE != null && processKeyBinding(ksE, e, WHEN_FOCUSED, pressed)) {
          return true;
      }
      if(processKeyBinding(ks, e, WHEN_FOCUSED, pressed))
          return true;

      /* We have no key binding. Let's try the path from our parent to the
       * window excluded. We store the path components so we can avoid
       * asking the same component twice.
       */
      Container parent = this;
      while (parent != null && !(parent instanceof Window) &&
             !(parent instanceof Applet)) {
          if(parent instanceof JComponent) {
              if(ksE != null && ((JComponent)parent).processKeyBinding(ksE, e,
                               WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, pressed))
                  return true;
              if(((JComponent)parent).processKeyBinding(ks, e,
                               WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, pressed))
                  return true;
          }
          // This is done so that the children of a JInternalFrame are
          // given precedence for WHEN_IN_FOCUSED_WINDOW bindings before
          // other components WHEN_IN_FOCUSED_WINDOW bindings. This also gives
          // more precedence to the WHEN_IN_FOCUSED_WINDOW bindings of the
          // JInternalFrame's children vs the
          // WHEN_ANCESTOR_OF_FOCUSED_COMPONENT bindings of the parents.
          // maybe generalize from JInternalFrame (like isFocusCycleRoot).
          if ((parent instanceof JInternalFrame) &&
              JComponent.processKeyBindingsForAllComponents(e,parent,pressed)){
              return true;
          }
          parent = parent.getParent();
      }

      /* No components between the focused component and the window is
       * actually interested by the key event. Let's try the other
       * JComponent in this window.
       */
      if(parent != null) {
        return JComponent.processKeyBindingsForAllComponents(e,parent,pressed);
      }
      return false;
    }

    static boolean processKeyBindingsForAllComponents(KeyEvent e,
                                      Container container, boolean pressed) {
        while (true) {
            if (KeyboardManager.getCurrentManager().fireKeyboardAction(
                                e, pressed, container)) {
                return true;
            }
            if (container instanceof Popup.HeavyWeightWindow) {
                container = ((Window)container).getOwner();
            }
            else {
                return false;
            }
        }
    }

    
Registers the text to display in a tool tip.
The text displays when the cursor lingers over the component.


See How to Use Tool Tips
in The Java Tutorial
for further documentation.

Params:
  • text –  the string to display; if the text is null,
             the tool tip is turned off for this component
See Also:
/**
     * Registers the text to display in a tool tip.
     * The text displays when the cursor lingers over the component.
     * <p>
     * See <a href="https://docs.oracle.com/javase/tutorial/uiswing/components/tooltip.html">How to Use Tool Tips</a>
     * in <em>The Java Tutorial</em>
     * for further documentation.
     *
     * @param text  the string to display; if the text is <code>null</code>,
     *              the tool tip is turned off for this component
     * @see #TOOL_TIP_TEXT_KEY
     */
    @BeanProperty(bound = false, preferred = true, description
            = "The text to display in a tool tip.")
    public void setToolTipText(String text) {
        String oldText = getToolTipText();
        putClientProperty(TOOL_TIP_TEXT_KEY, text);
        ToolTipManager toolTipManager = ToolTipManager.sharedInstance();
        if (text != null) {
            if (oldText == null) {
                toolTipManager.registerComponent(this);
            }
        } else {
            toolTipManager.unregisterComponent(this);
        }
    }

    
Returns the tooltip string that has been set with
setToolTipText.

See Also:
Returns:the text of the tool tip
/**
     * Returns the tooltip string that has been set with
     * <code>setToolTipText</code>.
     *
     * @return the text of the tool tip
     * @see #TOOL_TIP_TEXT_KEY
     */
    public String getToolTipText() {
        return (String)getClientProperty(TOOL_TIP_TEXT_KEY);
    }


    
Returns the string to be used as the tooltip for event.
By default this returns any string set using
setToolTipText.  If a component provides
more extensive API to support differing tooltips at different locations,
this method should be overridden.

Params:
  • event – the MouseEvent that initiated the ToolTip display
Returns:a string containing the  tooltip
/**
     * Returns the string to be used as the tooltip for <i>event</i>.
     * By default this returns any string set using
     * <code>setToolTipText</code>.  If a component provides
     * more extensive API to support differing tooltips at different locations,
     * this method should be overridden.
     *
     * @param event the {@code MouseEvent} that initiated the
     *              {@code ToolTip} display
     * @return a string containing the  tooltip
     */
    public String getToolTipText(MouseEvent event) {
        return getToolTipText();
    }

    
Returns the tooltip location in this component's coordinate system.
If null is returned, Swing will choose a location.
The default implementation returns null.

Params:
  • event –  the MouseEvent that caused the
         ToolTipManager to show the tooltip
Returns:always returns null
/**
     * Returns the tooltip location in this component's coordinate system.
     * If <code>null</code> is returned, Swing will choose a location.
     * The default implementation returns <code>null</code>.
     *
     * @param event  the <code>MouseEvent</code> that caused the
     *          <code>ToolTipManager</code> to show the tooltip
     * @return always returns <code>null</code>
     */
    public Point getToolTipLocation(MouseEvent event) {
        return null;
    }

    
Returns the preferred location to display the popup menu in this component's coordinate system. It is up to the look and feel to honor this property, some may choose to ignore it. If null, the look and feel will choose a suitable location. 
Params:
  • event – the MouseEvent that triggered the popup to be shown, or null if the popup is not being shown as the result of a mouse event
Returns:location to display the JPopupMenu, or null
Since:1.5
/**
     * Returns the preferred location to display the popup menu in this
     * component's coordinate system. It is up to the look and feel to
     * honor this property, some may choose to ignore it.
     * If {@code null}, the look and feel will choose a suitable location.
     *
     * @param event the {@code MouseEvent} that triggered the popup to be
     *        shown, or {@code null} if the popup is not being shown as the
     *        result of a mouse event
     * @return location to display the {@code JPopupMenu}, or {@code null}
     * @since 1.5
     */
    public Point getPopupLocation(MouseEvent event) {
        return null;
    }


    
Returns the instance of JToolTip that should be used
to display the tooltip.
Components typically would not override this method,
but it can be used to
cause different tooltips to be displayed differently.

Returns:the JToolTip used to display this toolTip
/**
     * Returns the instance of <code>JToolTip</code> that should be used
     * to display the tooltip.
     * Components typically would not override this method,
     * but it can be used to
     * cause different tooltips to be displayed differently.
     *
     * @return the <code>JToolTip</code> used to display this toolTip
     */
    public JToolTip createToolTip() {
        JToolTip tip = new JToolTip();
        tip.setComponent(this);
        return tip;
    }

    
Forwards the scrollRectToVisible() message to the
JComponent's parent. Components that can service
the request, such as JViewport,
override this method and perform the scrolling.

Params:
  • aRect – the visible Rectangle
See Also:
/**
     * Forwards the <code>scrollRectToVisible()</code> message to the
     * <code>JComponent</code>'s parent. Components that can service
     * the request, such as <code>JViewport</code>,
     * override this method and perform the scrolling.
     *
     * @param aRect the visible <code>Rectangle</code>
     * @see JViewport
     */
    public void scrollRectToVisible(Rectangle aRect) {
        Container parent;
        int dx = getX(), dy = getY();

        for (parent = getParent();
                 !(parent == null) &&
                 !(parent instanceof JComponent) &&
                 !(parent instanceof CellRendererPane);
             parent = parent.getParent()) {
             Rectangle bounds = parent.getBounds();

             dx += bounds.x;
             dy += bounds.y;
        }

        if (!(parent == null) && !(parent instanceof CellRendererPane)) {
            aRect.x += dx;
            aRect.y += dy;

            ((JComponent)parent).scrollRectToVisible(aRect);
            aRect.x -= dx;
            aRect.y -= dy;
        }
    }

    
Sets the autoscrolls property.
If true mouse dragged events will be
synthetically generated when the mouse is dragged
outside of the component's bounds and mouse motion
has paused (while the button continues to be held
down). The synthetic events make it appear that the
drag gesture has resumed in the direction established when
the component's boundary was crossed.  Components that
support autoscrolling must handle mouseDragged
events by calling scrollRectToVisible with a
rectangle that contains the mouse event's location.  All of
the Swing components that support item selection and are
typically displayed in a JScrollPane
(JTable, JList, JTree,
JTextArea, and JEditorPane)
already handle mouse dragged events in this way.  To enable
autoscrolling in any other component, add a mouse motion
listener that calls scrollRectToVisible.
For example, given a JPanel, myPanel:

MouseMotionListener doScrollRectToVisible = new MouseMotionAdapter() {
    public void mouseDragged(MouseEvent e) {
       Rectangle r = new Rectangle(e.getX(), e.getY(), 1, 1);
       ((JPanel)e.getSource()).scrollRectToVisible(r);
   }
};
myPanel.addMouseMotionListener(doScrollRectToVisible);


The default value of the autoScrolls
property is false.

Params:
  • autoscrolls – if true, synthetic mouse dragged events
  are generated when the mouse is dragged outside of a component's
  bounds and the mouse button continues to be held down; otherwise
  false
See Also:
/**
     * Sets the <code>autoscrolls</code> property.
     * If <code>true</code> mouse dragged events will be
     * synthetically generated when the mouse is dragged
     * outside of the component's bounds and mouse motion
     * has paused (while the button continues to be held
     * down). The synthetic events make it appear that the
     * drag gesture has resumed in the direction established when
     * the component's boundary was crossed.  Components that
     * support autoscrolling must handle <code>mouseDragged</code>
     * events by calling <code>scrollRectToVisible</code> with a
     * rectangle that contains the mouse event's location.  All of
     * the Swing components that support item selection and are
     * typically displayed in a <code>JScrollPane</code>
     * (<code>JTable</code>, <code>JList</code>, <code>JTree</code>,
     * <code>JTextArea</code>, and <code>JEditorPane</code>)
     * already handle mouse dragged events in this way.  To enable
     * autoscrolling in any other component, add a mouse motion
     * listener that calls <code>scrollRectToVisible</code>.
     * For example, given a <code>JPanel</code>, <code>myPanel</code>:
     * <pre>
     * MouseMotionListener doScrollRectToVisible = new MouseMotionAdapter() {
     *     public void mouseDragged(MouseEvent e) {
     *        Rectangle r = new Rectangle(e.getX(), e.getY(), 1, 1);
     *        ((JPanel)e.getSource()).scrollRectToVisible(r);
     *    }
     * };
     * myPanel.addMouseMotionListener(doScrollRectToVisible);
     * </pre>
     * The default value of the <code>autoScrolls</code>
     * property is <code>false</code>.
     *
     * @param autoscrolls if true, synthetic mouse dragged events
     *   are generated when the mouse is dragged outside of a component's
     *   bounds and the mouse button continues to be held down; otherwise
     *   false
     * @see #getAutoscrolls
     * @see JViewport
     * @see JScrollPane
     */
    @BeanProperty(bound = false, expert = true, description
            = "Determines if this component automatically scrolls its contents when dragged.")
    public void setAutoscrolls(boolean autoscrolls) {
        setFlag(AUTOSCROLLS_SET, true);
        if (this.autoscrolls != autoscrolls) {
            this.autoscrolls = autoscrolls;
            if (autoscrolls) {
                enableEvents(AWTEvent.MOUSE_EVENT_MASK);
                enableEvents(AWTEvent.MOUSE_MOTION_EVENT_MASK);
            }
            else {
                Autoscroller.stop(this);
            }
        }
    }

    
Gets the autoscrolls property.

See Also:
Returns:the value of the autoscrolls property
/**
     * Gets the <code>autoscrolls</code> property.
     *
     * @return the value of the <code>autoscrolls</code> property
     * @see JViewport
     * @see #setAutoscrolls
     */
    public boolean getAutoscrolls() {
        return autoscrolls;
    }

    
Sets the TransferHandler, which provides support for transfer of data into and out of this component via cut/copy/paste and drag and drop. This may be null if the component does not support data transfer operations. 
 If the new TransferHandler is not null, this method also installs a new DropTarget on the component to activate drop handling through the TransferHandler and activate any built-in support (such as calculating and displaying potential drop locations). If you do not wish for this component to respond in any way to drops, you can disable drop support entirely either by removing the drop target (setDropTarget(null)) or by de-activating it (getDropTaget().setActive(false)). 
 If the new TransferHandler is null, this method removes the drop target. 
 Under two circumstances, this method does not modify the drop target: First, if the existing drop target on this component was explicitly set by the developer to a non-null value. Second, if the system property suppressSwingDropSupport is true. The default value for the system property is false. 

Please see

How to Use Drag and Drop and Data Transfer,
a section in The Java Tutorial, for more information.

Params:
  • newHandler – the new TransferHandler
See Also:
Since:1.4
/**
     * Sets the {@code TransferHandler}, which provides support for transfer
     * of data into and out of this component via cut/copy/paste and drag
     * and drop. This may be {@code null} if the component does not support
     * data transfer operations.
     * <p>
     * If the new {@code TransferHandler} is not {@code null}, this method
     * also installs a <b>new</b> {@code DropTarget} on the component to
     * activate drop handling through the {@code TransferHandler} and activate
     * any built-in support (such as calculating and displaying potential drop
     * locations). If you do not wish for this component to respond in any way
     * to drops, you can disable drop support entirely either by removing the
     * drop target ({@code setDropTarget(null)}) or by de-activating it
     * ({@code getDropTaget().setActive(false)}).
     * <p>
     * If the new {@code TransferHandler} is {@code null}, this method removes
     * the drop target.
     * <p>
     * Under two circumstances, this method does not modify the drop target:
     * First, if the existing drop target on this component was explicitly
     * set by the developer to a {@code non-null} value. Second, if the
     * system property {@code suppressSwingDropSupport} is {@code true}. The
     * default value for the system property is {@code false}.
     * <p>
     * Please see
     * <a href="https://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html">
     * How to Use Drag and Drop and Data Transfer</a>,
     * a section in <em>The Java Tutorial</em>, for more information.
     *
     * @param newHandler the new {@code TransferHandler}
     *
     * @see TransferHandler
     * @see #getTransferHandler
     * @since 1.4
     */
    @BeanProperty(hidden = true, description
            = "Mechanism for transfer of data to and from the component")
    public void setTransferHandler(TransferHandler newHandler) {
        TransferHandler oldHandler = (TransferHandler)getClientProperty(
                                      JComponent_TRANSFER_HANDLER);
        putClientProperty(JComponent_TRANSFER_HANDLER, newHandler);

        SwingUtilities.installSwingDropTargetAsNecessary(this, newHandler);
        firePropertyChange("transferHandler", oldHandler, newHandler);
    }

    
Gets the transferHandler property.

See Also:
Returns: the value of the transferHandler property
Since:1.4
/**
     * Gets the <code>transferHandler</code> property.
     *
     * @return  the value of the <code>transferHandler</code> property
     *
     * @see TransferHandler
     * @see #setTransferHandler
     * @since 1.4
     */
    public TransferHandler getTransferHandler() {
        return (TransferHandler)getClientProperty(JComponent_TRANSFER_HANDLER);
    }

    
Calculates a custom drop location for this type of component,
representing where a drop at the given point should insert data.
null is returned if this component doesn't calculate
custom drop locations. In this case, TransferHandler
will provide a default DropLocation containing just
the point.

Params:
  • p – the point to calculate a drop location for
Returns:the drop location, or null
/**
     * Calculates a custom drop location for this type of component,
     * representing where a drop at the given point should insert data.
     * <code>null</code> is returned if this component doesn't calculate
     * custom drop locations. In this case, <code>TransferHandler</code>
     * will provide a default <code>DropLocation</code> containing just
     * the point.
     *
     * @param p the point to calculate a drop location for
     * @return the drop location, or <code>null</code>
     */
    TransferHandler.DropLocation dropLocationForPoint(Point p) {
        return null;
    }

    
Called to set or clear the drop location during a DnD operation.
In some cases, the component may need to use its internal selection
temporarily to indicate the drop location. To help facilitate this,
this method returns and accepts as a parameter a state object.
This state object can be used to store, and later restore, the selection
state. Whatever this method returns will be passed back to it in
future calls, as the state parameter. If it wants the DnD system to
continue storing the same state, it must pass it back every time.
Here's how this is used:


Let's say that on the first call to this method the component decides
to save some state (because it is about to use the selection to show
a drop index). It can return a state object to the caller encapsulating
any saved selection state. On a second call, let's say the drop location
is being changed to something else. The component doesn't need to
restore anything yet, so it simply passes back the same state object
to have the DnD system continue storing it. Finally, let's say this
method is messaged with null. This means DnD
is finished with this component for now, meaning it should restore
state. At this point, it can use the state parameter to restore
said state, and of course return null since there's
no longer anything to store.

Params:
  • location – the drop location (as calculated by
       dropLocationForPoint) or null
       if there's no longer a valid drop location
  • state – the state object saved earlier for this component,
       or null
  • forDrop – whether or not the method is being called because an
       actual drop occurred
Returns:any saved state for this component, or null if none
/**
     * Called to set or clear the drop location during a DnD operation.
     * In some cases, the component may need to use its internal selection
     * temporarily to indicate the drop location. To help facilitate this,
     * this method returns and accepts as a parameter a state object.
     * This state object can be used to store, and later restore, the selection
     * state. Whatever this method returns will be passed back to it in
     * future calls, as the state parameter. If it wants the DnD system to
     * continue storing the same state, it must pass it back every time.
     * Here's how this is used:
     * <p>
     * Let's say that on the first call to this method the component decides
     * to save some state (because it is about to use the selection to show
     * a drop index). It can return a state object to the caller encapsulating
     * any saved selection state. On a second call, let's say the drop location
     * is being changed to something else. The component doesn't need to
     * restore anything yet, so it simply passes back the same state object
     * to have the DnD system continue storing it. Finally, let's say this
     * method is messaged with <code>null</code>. This means DnD
     * is finished with this component for now, meaning it should restore
     * state. At this point, it can use the state parameter to restore
     * said state, and of course return <code>null</code> since there's
     * no longer anything to store.
     *
     * @param location the drop location (as calculated by
     *        <code>dropLocationForPoint</code>) or <code>null</code>
     *        if there's no longer a valid drop location
     * @param state the state object saved earlier for this component,
     *        or <code>null</code>
     * @param forDrop whether or not the method is being called because an
     *        actual drop occurred
     * @return any saved state for this component, or <code>null</code> if none
     */
    Object setDropLocation(TransferHandler.DropLocation location,
                           Object state,
                           boolean forDrop) {

        return null;
    }

    
Called to indicate to this component that DnD is done.
Needed by JTree.

/**
     * Called to indicate to this component that DnD is done.
     * Needed by <code>JTree</code>.
     */
    void dndDone() {
    }

    
Processes mouse events occurring on this component by
dispatching them to any registered
MouseListener objects, refer to Component.processMouseEvent(MouseEvent) for a complete description of this method. 
Params:
  • e – the mouse event
See Also:
Since:      1.5
/**
     * Processes mouse events occurring on this component by
     * dispatching them to any registered
     * <code>MouseListener</code> objects, refer to
     * {@link java.awt.Component#processMouseEvent(MouseEvent)}
     * for a complete description of this method.
     *
     * @param       e the mouse event
     * @see         java.awt.Component#processMouseEvent
     * @since       1.5
     */
    protected void processMouseEvent(MouseEvent e) {
        if (autoscrolls && e.getID() == MouseEvent.MOUSE_RELEASED) {
            Autoscroller.stop(this);
        }
        super.processMouseEvent(e);
    }

    
Processes mouse motion events, such as MouseEvent.MOUSE_DRAGGED.

Params:
  • e – the MouseEvent
See Also:
/**
     * Processes mouse motion events, such as MouseEvent.MOUSE_DRAGGED.
     *
     * @param e the <code>MouseEvent</code>
     * @see MouseEvent
     */
    protected void processMouseMotionEvent(MouseEvent e) {
        boolean dispatch = true;
        if (autoscrolls && e.getID() == MouseEvent.MOUSE_DRAGGED) {
            // We don't want to do the drags when the mouse moves if we're
            // autoscrolling.  It makes it feel spastic.
            dispatch = !Autoscroller.isRunning(this);
            Autoscroller.processMouseDragged(e);
        }
        if (dispatch) {
            super.processMouseMotionEvent(e);
        }
    }

    // Inner classes can't get at this method from a super class
    void superProcessMouseMotionEvent(MouseEvent e) {
        super.processMouseMotionEvent(e);
    }

    
This is invoked by the RepaintManager if
createImage is called on the component.

Params:
  • newValue – true if the double buffer image was created from this component
/**
     * This is invoked by the <code>RepaintManager</code> if
     * <code>createImage</code> is called on the component.
     *
     * @param newValue true if the double buffer image was created from this component
     */
    void setCreatedDoubleBuffer(boolean newValue) {
        setFlag(CREATED_DOUBLE_BUFFER, newValue);
    }

    
Returns true if the RepaintManager
created the double buffer image from the component.

Returns:true if this component had a double buffer image, false otherwise
/**
     * Returns true if the <code>RepaintManager</code>
     * created the double buffer image from the component.
     *
     * @return true if this component had a double buffer image, false otherwise
     */
    boolean getCreatedDoubleBuffer() {
        return getFlag(CREATED_DOUBLE_BUFFER);
    }

    
ActionStandin is used as a standin for
ActionListeners that are
added via registerKeyboardAction.

/**
     * <code>ActionStandin</code> is used as a standin for
     * <code>ActionListeners</code> that are
     * added via <code>registerKeyboardAction</code>.
     */
    final class ActionStandin implements Action {
        private final ActionListener actionListener;
        private final String command;
        // This will be non-null if actionListener is an Action.
        private final Action action;

        ActionStandin(ActionListener actionListener, String command) {
            this.actionListener = actionListener;
            if (actionListener instanceof Action) {
                this.action = (Action)actionListener;
            }
            else {
                this.action = null;
            }
            this.command = command;
        }

        public Object getValue(String key) {
            if (key != null) {
                if (key.equals(Action.ACTION_COMMAND_KEY)) {
                    return command;
                }
                if (action != null) {
                    return action.getValue(key);
                }
                if (key.equals(NAME)) {
                    return "ActionStandin";
                }
            }
            return null;
        }

        public boolean isEnabled() {
            if (actionListener == null) {
                // This keeps the old semantics where
                // registerKeyboardAction(null) would essentialy remove
                // the binding. We don't remove the binding from the
                // InputMap as that would still allow parent InputMaps
                // bindings to be accessed.
                return false;
            }
            if (action == null) {
                return true;
            }
            return action.isEnabled();
        }

        public void actionPerformed(ActionEvent ae) {
            if (actionListener != null) {
                actionListener.actionPerformed(ae);
            }
        }

        // We don't allow any values to be added.
        public void putValue(String key, Object value) {}

        // Does nothing, our enabledness is determiend from our asociated
        // action.
        public void setEnabled(boolean b) { }

        public void addPropertyChangeListener
                    (PropertyChangeListener listener) {}
        public void removePropertyChangeListener
                          (PropertyChangeListener listener) {}
    }


    // This class is used by the KeyboardState class to provide a single
    // instance that can be stored in the AppContext.
    static final class IntVector {
        int[] array = null;
        int count = 0;
        int capacity = 0;

        int size() {
            return count;
        }

        int elementAt(int index) {
            return array[index];
        }

        void addElement(int value) {
            if (count == capacity) {
                capacity = (capacity + 2) * 2;
                int[] newarray = new int[capacity];
                if (count > 0) {
                    System.arraycopy(array, 0, newarray, 0, count);
                }
                array = newarray;
            }
            array[count++] = value;
        }

        void setElementAt(int value, int index) {
            array[index] = value;
        }
    }

    @SuppressWarnings("serial")
    static class KeyboardState implements Serializable {
        private static final Object keyCodesKey =
            JComponent.KeyboardState.class;

        // Get the array of key codes from the AppContext.
        static IntVector getKeyCodeArray() {
            IntVector iv =
                (IntVector)SwingUtilities.appContextGet(keyCodesKey);
            if (iv == null) {
                iv = new IntVector();
                SwingUtilities.appContextPut(keyCodesKey, iv);
            }
            return iv;
        }

        static void registerKeyPressed(int keyCode) {
            IntVector kca = getKeyCodeArray();
            int count = kca.size();
            int i;
            for(i=0;i<count;i++) {
                if(kca.elementAt(i) == -1){
                    kca.setElementAt(keyCode, i);
                    return;
                }
            }
            kca.addElement(keyCode);
        }

        static void registerKeyReleased(int keyCode) {
            IntVector kca = getKeyCodeArray();
            int count = kca.size();
            int i;
            for(i=0;i<count;i++) {
                if(kca.elementAt(i) == keyCode) {
                    kca.setElementAt(-1, i);
                    return;
                }
            }
        }

        static boolean keyIsPressed(int keyCode) {
            IntVector kca = getKeyCodeArray();
            int count = kca.size();
            int i;
            for(i=0;i<count;i++) {
                if(kca.elementAt(i) == keyCode) {
                    return true;
                }
            }
            return false;
        }

        
Updates internal state of the KeyboardState and returns true
if the event should be processed further.

/**
         * Updates internal state of the KeyboardState and returns true
         * if the event should be processed further.
         */
        static boolean shouldProcess(KeyEvent e) {
            switch (e.getID()) {
            case KeyEvent.KEY_PRESSED:
                if (!keyIsPressed(e.getKeyCode())) {
                    registerKeyPressed(e.getKeyCode());
                }
                return true;
            case KeyEvent.KEY_RELEASED:
                // We are forced to process VK_PRINTSCREEN separately because
                // the Windows doesn't generate the key pressed event for
                // printscreen and it block the processing of key release
                // event for printscreen.
                if (keyIsPressed(e.getKeyCode()) || e.getKeyCode()==KeyEvent.VK_PRINTSCREEN) {
                    registerKeyReleased(e.getKeyCode());
                    return true;
                }
                return false;
            case KeyEvent.KEY_TYPED:
                return true;
            default:
                // Not a known KeyEvent type, bail.
                return false;
            }
      }
    }

    static final sun.awt.RequestFocusController focusController =
        new sun.awt.RequestFocusController() {
            public boolean acceptRequestFocus(Component from, Component to,
                                              boolean temporary, boolean focusedWindowChangeAllowed,
                                              FocusEvent.Cause cause)
            {
                if ((to == null) || !(to instanceof JComponent)) {
                    return true;
                }

                if ((from == null) || !(from instanceof JComponent)) {
                    return true;
                }

                JComponent target = (JComponent) to;
                if (!target.getVerifyInputWhenFocusTarget()) {
                    return true;
                }

                JComponent jFocusOwner = (JComponent)from;
                InputVerifier iv = jFocusOwner.getInputVerifier();

                if (iv == null) {
                    return true;
                } else {
                    Object currentSource = SwingUtilities.appContextGet(
                            INPUT_VERIFIER_SOURCE_KEY);
                    if (currentSource == jFocusOwner) {
                        // We're currently calling into the InputVerifier
                        // for this component, so allow the focus change.
                        return true;
                    }
                    SwingUtilities.appContextPut(INPUT_VERIFIER_SOURCE_KEY,
                                                 jFocusOwner);
                    try {
                        return iv.shouldYieldFocus(jFocusOwner, target);
                    } finally {
                        if (currentSource != null) {
                            // We're already in the InputVerifier for
                            // currentSource. By resetting the currentSource
                            // we ensure that if the InputVerifier for
                            // currentSource does a requestFocus, we don't
                            // try and run the InputVerifier again.
                            SwingUtilities.appContextPut(
                                INPUT_VERIFIER_SOURCE_KEY, currentSource);
                        } else {
                            SwingUtilities.appContextRemove(
                                INPUT_VERIFIER_SOURCE_KEY);
                        }
                    }
                }
            }
        };

    /*
     * --- Accessibility Support ---
     */

    
Deprecated:As of JDK version 1.1,
replaced by java.awt.Component.setEnabled(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>java.awt.Component.setEnabled(boolean)</code>.
     */
    @Deprecated
    public void enable() {
        if (isEnabled() != true) {
            super.enable();
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                    AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                    null, AccessibleState.ENABLED);
            }
        }
    }

    
Deprecated:As of JDK version 1.1,
replaced by java.awt.Component.setEnabled(boolean).
/**
     * @deprecated As of JDK version 1.1,
     * replaced by <code>java.awt.Component.setEnabled(boolean)</code>.
     */
    @Deprecated
    public void disable() {
        if (isEnabled() != false) {
            super.disable();
            if (accessibleContext != null) {
                accessibleContext.firePropertyChange(
                    AccessibleContext.ACCESSIBLE_STATE_PROPERTY,
                    AccessibleState.ENABLED, null);
            }
        }
    }

    
Inner class of JComponent 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.


Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
/**
     * Inner class of JComponent 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>
     * <strong>Warning:</strong>
     * Serialized objects of this class will not be compatible with
     * future Swing releases. The current serialization support is
     * appropriate for short term storage or RMI between applications running
     * the same version of Swing.  As of 1.4, support for long term storage
     * of all JavaBeans&trade;
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     */
    @SuppressWarnings("serial") // Same-version serialization only
    public abstract class AccessibleJComponent extends AccessibleAWTContainer
       implements AccessibleExtendedComponent
    {
        
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 AccessibleJComponent() {
            super();
        }

        
Number of PropertyChangeListener objects registered. It's used
to add/remove ContainerListener and FocusListener to track
target JComponent's state

/**
         * Number of PropertyChangeListener objects registered. It's used
         * to add/remove ContainerListener and FocusListener to track
         * target JComponent's state
         */
        private transient volatile int propertyListenersCount = 0;

        
This field duplicates the function of the accessibleAWTFocusHandler field
in java.awt.Component.AccessibleAWTComponent, so it has been deprecated.

/**
         * This field duplicates the function of the accessibleAWTFocusHandler field
         * in java.awt.Component.AccessibleAWTComponent, so it has been deprecated.
         */
        @Deprecated
        protected FocusListener accessibleFocusHandler = null;

        
Fire PropertyChange listener, if one is registered,
when children added/removed.

/**
         * Fire PropertyChange listener, if one is registered,
         * when children added/removed.
         */
        protected class AccessibleContainerHandler
            implements ContainerListener {
            public void componentAdded(ContainerEvent e) {
                Component c = e.getChild();
                if (c != null && c instanceof Accessible) {
                    AccessibleJComponent.this.firePropertyChange(
                        AccessibleContext.ACCESSIBLE_CHILD_PROPERTY,
                        null, c.getAccessibleContext());
                }
            }
            public void componentRemoved(ContainerEvent e) {
                Component c = e.getChild();
                if (c != null && c instanceof Accessible) {
                    AccessibleJComponent.this.firePropertyChange(
                        AccessibleContext.ACCESSIBLE_CHILD_PROPERTY,
                        c.getAccessibleContext(), null);
                }
            }
        }

        
Fire PropertyChange listener, if one is registered,
when focus events happen

Since:1.3
Deprecated:This class is no longer used or needed. java.awt.Component.AccessibleAWTComponent provides the same functionality and it is handled in Component.
/**
         * Fire PropertyChange listener, if one is registered,
         * when focus events happen
         * @since 1.3
         * @deprecated This class is no longer used or needed.
         * {@code java.awt.Component.AccessibleAWTComponent} provides
         * the same functionality and it is handled in {@code Component}.
         */
        @Deprecated
        protected class AccessibleFocusHandler implements FocusListener {
           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 AccessibleFocusHandler


        
Adds a PropertyChangeListener to the listener list.

Params:
  • listener –  the PropertyChangeListener to be added
/**
         * Adds a PropertyChangeListener to the listener list.
         *
         * @param listener  the PropertyChangeListener to be added
         */
        public void addPropertyChangeListener(PropertyChangeListener listener) {
            super.addPropertyChangeListener(listener);
        }

        
Removes a PropertyChangeListener from the listener list.
This removes a PropertyChangeListener that was registered
for all properties.

Params:
  • listener –  the PropertyChangeListener to be removed
/**
         * Removes 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) {
            super.removePropertyChangeListener(listener);
        }



        
Recursively search through the border hierarchy (if it exists)
for a TitledBorder with a non-null title.  This does a depth
first search on first the inside borders then the outside borders.
The assumption is that titles make really pretty inside borders
but not very pretty outside borders in compound border situations.
It's rather arbitrary, but hopefully decent UI programmers will
not create multiple titled borders for the same component.

Params:
  • b –  the Border for which to retrieve its title
Returns:the border's title as a String, null if it has no title
/**
         * Recursively search through the border hierarchy (if it exists)
         * for a TitledBorder with a non-null title.  This does a depth
         * first search on first the inside borders then the outside borders.
         * The assumption is that titles make really pretty inside borders
         * but not very pretty outside borders in compound border situations.
         * It's rather arbitrary, but hopefully decent UI programmers will
         * not create multiple titled borders for the same component.
         *
         * @param b  the {@code Border} for which to retrieve its title
         * @return the border's title as a {@code String}, null if it has
         *         no title
         */
        protected String getBorderTitle(Border b) {
            String s;
            if (b instanceof TitledBorder) {
                return ((TitledBorder) b).getTitle();
            } else if (b instanceof CompoundBorder) {
                s = getBorderTitle(((CompoundBorder) b).getInsideBorder());
                if (s == null) {
                    s = getBorderTitle(((CompoundBorder) b).getOutsideBorder());
                }
                return s;
            } else {
                return null;
            }
        }

        // 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 (such as a menu item), the
accessible name should be the text of the object (for example,
"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 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 (such as a menu item), the
         * accessible name should be the text of the object (for example,
         * "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 null if this
         *         object does not have a name
         * @see AccessibleContext#setAccessibleName
         */
        public String getAccessibleName() {
            String name = accessibleName;

            // fallback to the client name property
            //
            if (name == null) {
                name = (String)getClientProperty(AccessibleContext.ACCESSIBLE_NAME_PROPERTY);
            }

            // fallback to the titled border if it exists
            //
            if (name == null) {
                name = getBorderTitle(getBorder());
            }

            // fallback to the label labeling us if it exists
            //
            if (name == null) {
                Object o = getClientProperty(JLabel.LABELED_BY_PROPERTY);
                if (o instanceof Accessible) {
                    AccessibleContext ac = ((Accessible) o).getAccessibleContext();
                    if (ac != null) {
                        name = ac.getAccessibleName();
                    }
                }
            }
            return name;
        }

        
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 - for example 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 - for example 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 null if
         * this object does not have a description
         * @see AccessibleContext#setAccessibleDescription
         */
        public String getAccessibleDescription() {
            String description = accessibleDescription;

            // fallback to the client description property
            //
            if (description == null) {
                description = (String)getClientProperty(AccessibleContext.ACCESSIBLE_DESCRIPTION_PROPERTY);
            }

            // fallback to the tool tip text if it exists
            //
            if (description == null) {
                try {
                    description = getToolTipText();
                } catch (Exception e) {
                    // Just in case the subclass overrode the
                    // getToolTipText method and actually
                    // requires a MouseEvent.
                    // [[[FIXME:  WDW - we probably should require this
                    // method to take a MouseEvent and just pass it on
                    // to getToolTipText.  The swing-feedback traffic
                    // leads me to believe getToolTipText might change,
                    // though, so I was hesitant to make this change at
                    // this time.]]]
                }
            }

            // fallback to the label labeling us if it exists
            //
            if (description == null) {
                Object o = getClientProperty(JLabel.LABELED_BY_PROPERTY);
                if (o instanceof Accessible) {
                    AccessibleContext ac = ((Accessible) o).getAccessibleContext();
                    if (ac != null) {
                        description = ac.getAccessibleDescription();
                    }
                }
            }

            return description;
        }

        
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 AccessibleRole describing the role of the
         * object
         * @see AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.SWING_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 AccessibleStateSet containing the current
         * state set of the object
         * @see AccessibleState
         */
        public AccessibleStateSet getAccessibleStateSet() {
            AccessibleStateSet states = super.getAccessibleStateSet();
            if (JComponent.this.isOpaque()) {
                states.add(AccessibleState.OPAQUE);
            }
            return states;
        }

        
Returns the number of accessible children in the object.  If all
of the children of this object implement Accessible, than 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 Accessible, than this
         * method should return the number of children of this object.
         *
         * @return the number of accessible children in the object.
         */
        public int getAccessibleChildrenCount() {
            return super.getAccessibleChildrenCount();
        }

        
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 Accessible child of the object.
         *
         * @param i zero-based index of child
         * @return the nth Accessible child of the object
         */
        public Accessible getAccessibleChild(int i) {
            return super.getAccessibleChild(i);
        }

        // ----- AccessibleExtendedComponent

        
Returns the AccessibleExtendedComponent

Returns:the AccessibleExtendedComponent
/**
         * Returns the AccessibleExtendedComponent
         *
         * @return the AccessibleExtendedComponent
         */
        AccessibleExtendedComponent getAccessibleExtendedComponent() {
            return this;
        }

        
Returns the tool tip text

Returns:the tool tip text, if supported, of the object;
otherwise, null
Since:1.4
/**
         * Returns the tool tip text
         *
         * @return the tool tip text, if supported, of the object;
         * otherwise, null
         * @since 1.4
         */
        public String getToolTipText() {
            return JComponent.this.getToolTipText();
        }

        
Returns the titled border text

Returns:the titled border text, if supported, of the object;
otherwise, null
Since:1.4
/**
         * Returns the titled border text
         *
         * @return the titled border text, if supported, of the object;
         * otherwise, null
         * @since 1.4
         */
        public String getTitledBorderText() {
            Border border = JComponent.this.getBorder();
            if (border instanceof TitledBorder) {
                return ((TitledBorder)border).getTitle();
            } else {
                return null;
            }
        }

        
Returns key bindings associated with this object

See Also:
Returns:the key bindings, if supported, of the object;
otherwise, null
Since:1.4
/**
         * Returns key bindings associated with this object
         *
         * @return the key bindings, if supported, of the object;
         * otherwise, null
         * @see AccessibleKeyBinding
         * @since 1.4
         */
        public AccessibleKeyBinding getAccessibleKeyBinding(){
            // Try to get the linked label's mnemonic if it exists
            Object o = getClientProperty(JLabel.LABELED_BY_PROPERTY);
            if (o instanceof Accessible){
                AccessibleContext ac = ((Accessible) o).getAccessibleContext();
                if (ac != null){
                    AccessibleComponent comp = ac.getAccessibleComponent();
                    if (! (comp instanceof AccessibleExtendedComponent))
                        return null;
                    return ((AccessibleExtendedComponent)comp).getAccessibleKeyBinding();
                }
            }
            return null;
        }
    } // inner class AccessibleJComponent


    
Returns an ArrayTable used for
key/value "client properties" for this component. If the
clientProperties table doesn't exist, an empty one
will be created.

See Also:
Returns:an ArrayTable
/**
     * Returns an <code>ArrayTable</code> used for
     * key/value "client properties" for this component. If the
     * <code>clientProperties</code> table doesn't exist, an empty one
     * will be created.
     *
     * @return an ArrayTable
     * @see #putClientProperty
     * @see #getClientProperty
     */
    private ArrayTable getClientProperties() {
        if (clientProperties == null) {
            clientProperties = new ArrayTable();
        }
        return clientProperties;
    }


    
Returns the value of the property with the specified key.  Only
properties added with putClientProperty will return
a non-null value.

Params:
  • key – the being queried
See Also:
Returns:the value of this property or null
/**
     * Returns the value of the property with the specified key.  Only
     * properties added with <code>putClientProperty</code> will return
     * a non-<code>null</code> value.
     *
     * @param key the being queried
     * @return the value of this property or <code>null</code>
     * @see #putClientProperty
     */
    public final Object getClientProperty(Object key) {
        if (key == RenderingHints.KEY_TEXT_ANTIALIASING) {
            return aaHint;
        } else if (key == RenderingHints.KEY_TEXT_LCD_CONTRAST) {
            return lcdRenderingHint;
        }
         if(clientProperties == null) {
            return null;
        } else {
            synchronized(clientProperties) {
                return clientProperties.get(key);
            }
        }
    }

    
Adds an arbitrary key/value "client property" to this component.


The get/putClientProperty methods provide access to
a small per-instance hashtable. Callers can use get/putClientProperty
to annotate components that were created by another module.
For example, a
layout manager might store per child constraints this way. For example:

componentA.putClientProperty("to the left of", componentB);


If value is null this method will remove the property.
Changes to client properties are reported with
PropertyChange events.
The name of the property (for the sake of PropertyChange
events) is key.toString().


The clientProperty dictionary is not intended to
support large
scale extensions to JComponent nor should be it considered an
alternative to subclassing when designing a new component.

Params:
  • key – the new client property key
  • value – the new client property value; if null
         this method will remove the property
See Also:
/**
     * Adds an arbitrary key/value "client property" to this component.
     * <p>
     * The <code>get/putClientProperty</code> methods provide access to
     * a small per-instance hashtable. Callers can use get/putClientProperty
     * to annotate components that were created by another module.
     * For example, a
     * layout manager might store per child constraints this way. For example:
     * <pre>
     * componentA.putClientProperty("to the left of", componentB);
     * </pre>
     * If value is <code>null</code> this method will remove the property.
     * Changes to client properties are reported with
     * <code>PropertyChange</code> events.
     * The name of the property (for the sake of PropertyChange
     * events) is <code>key.toString()</code>.
     * <p>
     * The <code>clientProperty</code> dictionary is not intended to
     * support large
     * scale extensions to JComponent nor should be it considered an
     * alternative to subclassing when designing a new component.
     *
     * @param key the new client property key
     * @param value the new client property value; if <code>null</code>
     *          this method will remove the property
     * @see #getClientProperty
     * @see #addPropertyChangeListener
     */
    public final void putClientProperty(Object key, Object value) {
        if (key == RenderingHints.KEY_TEXT_ANTIALIASING) {
            aaHint = value;
            return;
        } else if (key == RenderingHints.KEY_TEXT_LCD_CONTRAST) {
            lcdRenderingHint = value;
            return;
        }
        if (value == null && clientProperties == null) {
            // Both the value and ArrayTable are null, implying we don't
            // have to do anything.
            return;
        }
        ArrayTable clientProperties = getClientProperties();
        Object oldValue;
        synchronized(clientProperties) {
            oldValue = clientProperties.get(key);
            if (value != null) {
                clientProperties.put(key, value);
            } else if (oldValue != null) {
                clientProperties.remove(key);
            } else {
                // old == new == null
                return;
            }
        }
        clientPropertyChanged(key, oldValue, value);
        firePropertyChange(key.toString(), oldValue, value);
    }

    // Invoked from putClientProperty.  This is provided for subclasses
    // in Swing.
    void clientPropertyChanged(Object key, Object oldValue,
                               Object newValue) {
    }


    /*
     * Sets the property with the specified name to the specified value if
     * the property has not already been set by the client program.
     * This method is used primarily to set UI defaults for properties
     * with primitive types, where the values cannot be marked with
     * UIResource.
     * @see LookAndFeel#installProperty
     * @param propertyName String containing the name of the property
     * @param value Object containing the property value
     */
    void setUIProperty(String propertyName, Object value) {
        if (propertyName == "opaque") {
            if (!getFlag(OPAQUE_SET)) {
                setOpaque(((Boolean)value).booleanValue());
                setFlag(OPAQUE_SET, false);
            }
        } else if (propertyName == "autoscrolls") {
            if (!getFlag(AUTOSCROLLS_SET)) {
                setAutoscrolls(((Boolean)value).booleanValue());
                setFlag(AUTOSCROLLS_SET, false);
            }
        } else if (propertyName == "focusTraversalKeysForward") {
            @SuppressWarnings("unchecked")
            Set<AWTKeyStroke> strokeSet = (Set<AWTKeyStroke>) value;
            if (!getFlag(FOCUS_TRAVERSAL_KEYS_FORWARD_SET)) {
                super.setFocusTraversalKeys(KeyboardFocusManager.
                                            FORWARD_TRAVERSAL_KEYS,
                                            strokeSet);
            }
        } else if (propertyName == "focusTraversalKeysBackward") {
            @SuppressWarnings("unchecked")
            Set<AWTKeyStroke> strokeSet = (Set<AWTKeyStroke>) value;
            if (!getFlag(FOCUS_TRAVERSAL_KEYS_BACKWARD_SET)) {
                super.setFocusTraversalKeys(KeyboardFocusManager.
                                            BACKWARD_TRAVERSAL_KEYS,
                                            strokeSet);
            }
        } else {
            throw new IllegalArgumentException("property \""+
                                               propertyName+ "\" cannot be set using this method");
        }
    }


    
Sets the focus traversal keys for a given traversal operation for this Component. Refer to Component.setFocusTraversalKeys for a complete description of this method. 
 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:1.5
/**
     * Sets the focus traversal keys for a given traversal operation for this
     * Component.
     * Refer to
     * {@link java.awt.Component#setFocusTraversalKeys}
     * for a complete description of this method.
     * <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 java.awt.KeyboardFocusManager#FORWARD_TRAVERSAL_KEYS
     * @see java.awt.KeyboardFocusManager#BACKWARD_TRAVERSAL_KEYS
     * @see java.awt.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 1.5
     */
    public void
        setFocusTraversalKeys(int id, Set<? extends AWTKeyStroke> keystrokes)
    {
        if (id == KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS) {
            setFlag(FOCUS_TRAVERSAL_KEYS_FORWARD_SET,true);
        } else if (id == KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS) {
            setFlag(FOCUS_TRAVERSAL_KEYS_BACKWARD_SET,true);
        }
        super.setFocusTraversalKeys(id,keystrokes);
    }

    /* --- Transitional java.awt.Component Support ---
     * The methods and fields in this section will migrate to
     * java.awt.Component in the next JDK release.
     */

    
Returns true if this component is lightweight, that is, if it doesn't
have a native window system peer.

Params:
  • c –  the Component to be checked
Returns:true if this component is lightweight
/**
     * Returns true if this component is lightweight, that is, if it doesn't
     * have a native window system peer.
     *
     * @param c  the {@code Component} to be checked
     * @return true if this component is lightweight
     */
    public static boolean isLightweightComponent(Component c) {
        // TODO we cannot call c.isLightweight() because it is incorrectly
        // overriden in DelegateContainer on osx.
        return AWTAccessor.getComponentAccessor().isLightweight(c);
    }


    
Params:
  • x –  the new horizontal location
  • y –  the new vertical location
  • w –  the new width
  • h –  the new height
See Also:
Deprecated:As of JDK 5,
replaced by Component.setBounds(int, int, int, int).


Moves and resizes this component.
/**
     * @deprecated As of JDK 5,
     * replaced by <code>Component.setBounds(int, int, int, int)</code>.
     * <p>
     * Moves and resizes this component.
     *
     * @param x  the new horizontal location
     * @param y  the new vertical location
     * @param w  the new width
     * @param h  the new height
     * @see java.awt.Component#setBounds
     */
    @Deprecated
    public void reshape(int x, int y, int w, int h) {
        super.reshape(x, y, w, h);
    }


    
Stores the bounds of this component into "return value"
rv and returns 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 component's bounds
Returns:rv; if rv is null
         return a newly created Rectangle with this
         component's bounds
/**
     * Stores the bounds of this component into "return value"
     * <code>rv</code> and returns <code>rv</code>.
     * If <code>rv</code> is <code>null</code> a new <code>Rectangle</code>
     * is allocated.  This version of <code>getBounds</code> is useful
     * if the caller wants to avoid allocating a new <code>Rectangle</code>
     * object on the heap.
     *
     * @param rv the return value, modified to the component's bounds
     * @return <code>rv</code>; if <code>rv</code> is <code>null</code>
     *          return a newly created <code>Rectangle</code> with this
     *          component's bounds
     */
    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 returns 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 component's size
Returns:rv
/**
     * Stores the width/height of this component into "return value"
     * <code>rv</code> and returns <code>rv</code>.
     * If <code>rv</code> is <code>null</code> a new <code>Dimension</code>
     * object is allocated.  This version of <code>getSize</code>
     * is useful if the caller wants to avoid allocating a new
     * <code>Dimension</code> object on the heap.
     *
     * @param rv the return value, modified to the component's size
     * @return <code>rv</code>
     */
    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 returns 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 component's location
Returns:rv
/**
     * Stores the x,y origin of this component into "return value"
     * <code>rv</code> and returns <code>rv</code>.
     * If <code>rv</code> is <code>null</code> a new <code>Point</code>
     * is allocated.  This version of <code>getLocation</code> is useful
     * if the caller wants to avoid allocating a new <code>Point</code>
     * object on the heap.
     *
     * @param rv the return value, modified to the component's location
     * @return <code>rv</code>
     */
    public Point getLocation(Point rv) {
        if (rv == null) {
            return new Point(getX(), getY());
        }
        else {
            rv.setLocation(getX(), getY());
            return rv;
        }
    }


    
Returns the current x coordinate of the component's 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 component's origin
/**
     * Returns the current x coordinate of the component's origin.
     * This method is preferable to writing
     * <code>component.getBounds().x</code>, or
     * <code>component.getLocation().x</code> because it doesn't cause any
     * heap allocations.
     *
     * @return the current x coordinate of the component's origin
     */
    @BeanProperty(bound = false)
    public int getX() { return super.getX(); }


    
Returns the current y coordinate of the component's 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 component's origin
/**
     * Returns the current y coordinate of the component's origin.
     * This method is preferable to writing
     * <code>component.getBounds().y</code>, or
     * <code>component.getLocation().y</code> because it doesn't cause any
     * heap allocations.
     *
     * @return the current y coordinate of the component's origin
     */
    @BeanProperty(bound = false)
    public int getY() { return super.getY(); }


    
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
/**
     * Returns the current width of this component.
     * This method is preferable to writing
     * <code>component.getBounds().width</code>, or
     * <code>component.getSize().width</code> because it doesn't cause any
     * heap allocations.
     *
     * @return the current width of this component
     */
    @BeanProperty(bound = false)
    public int getWidth() { return super.getWidth(); }


    
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
/**
     * Returns the current height of this component.
     * This method is preferable to writing
     * <code>component.getBounds().height</code>, or
     * <code>component.getSize().height</code> because it doesn't cause any
     * heap allocations.
     *
     * @return the current height of this component
     */
    @BeanProperty(bound = false)
    public int getHeight() { return super.getHeight(); }

    
Returns true if this component is completely opaque.


An opaque component paints every pixel within its
rectangular bounds. A non-opaque component paints only a subset of
its pixels or none at all, allowing the pixels underneath it to
"show through".  Therefore, a component that does not fully paint
its pixels 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
/**
     * Returns true if this component is completely opaque.
     * <p>
     * An opaque component paints every pixel within its
     * rectangular bounds. A non-opaque component paints only a subset of
     * its pixels or none at all, allowing the pixels underneath it to
     * "show through".  Therefore, a component that does not fully paint
     * its pixels 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 #setOpaque
     */
    public boolean isOpaque() {
        return getFlag(IS_OPAQUE);
    }

    
If true the component paints every pixel within its bounds.
Otherwise, the component may not paint some or all of its
pixels, allowing the underlying pixels to show through.


The default value of this property is false for JComponent.
However, the default value for this property on most standard
JComponent subclasses (such as JButton and
JTree) is look-and-feel dependent.

Params:
  • isOpaque –  true if this component should be opaque
See Also:
/**
     * If true the component paints every pixel within its bounds.
     * Otherwise, the component may not paint some or all of its
     * pixels, allowing the underlying pixels to show through.
     * <p>
     * The default value of this property is false for <code>JComponent</code>.
     * However, the default value for this property on most standard
     * <code>JComponent</code> subclasses (such as <code>JButton</code> and
     * <code>JTree</code>) is look-and-feel dependent.
     *
     * @param isOpaque  true if this component should be opaque
     * @see #isOpaque
     */
    @BeanProperty(expert = true, description
            = "The component's opacity")
    public void setOpaque(boolean isOpaque) {
        boolean oldValue = getFlag(IS_OPAQUE);
        setFlag(IS_OPAQUE, isOpaque);
        setFlag(OPAQUE_SET, true);
        firePropertyChange("opaque", oldValue, isOpaque);
    }


    
If the specified rectangle is completely obscured by any of this
component's opaque children then returns true.  Only direct children
are considered, more distant descendants are ignored.  A
JComponent is opaque if
JComponent.isOpaque() returns true, other lightweight
components are always considered transparent, and heavyweight components
are always considered opaque.

Params:
  • x –  x value of specified rectangle
  • y –  y value of specified rectangle
  • width –  width of specified rectangle
  • height – height of specified rectangle
Returns:true if the specified rectangle is obscured by an opaque child
/**
     * If the specified rectangle is completely obscured by any of this
     * component's opaque children then returns true.  Only direct children
     * are considered, more distant descendants are ignored.  A
     * <code>JComponent</code> is opaque if
     * <code>JComponent.isOpaque()</code> returns true, other lightweight
     * components are always considered transparent, and heavyweight components
     * are always considered opaque.
     *
     * @param x  x value of specified rectangle
     * @param y  y value of specified rectangle
     * @param width  width of specified rectangle
     * @param height height of specified rectangle
     * @return true if the specified rectangle is obscured by an opaque child
     */
    boolean rectangleIsObscured(int x,int y,int width,int height)
    {
        int numChildren = getComponentCount();

        for(int i = 0; i < numChildren; i++) {
            Component child = getComponent(i);
            int cx, cy, cw, ch;

            cx = child.getX();
            cy = child.getY();
            cw = child.getWidth();
            ch = child.getHeight();

            if (x >= cx && (x + width) <= (cx + cw) &&
                y >= cy && (y + height) <= (cy + ch) && child.isVisible()) {

                if(child instanceof JComponent) {
//                  System.out.println("A) checking opaque: " + ((JComponent)child).isOpaque() + "  " + child);
//                  System.out.print("B) ");
//                  Thread.dumpStack();
                    return child.isOpaque();
                } else {
                    /** Sometimes a heavy weight can have a bound larger than its peer size
                     *  so we should always draw under heavy weights
                     */
                    return false;
                }
            }
        }

        return false;
    }


    
Returns the Component's "visible rect rectangle" -  the
intersection of the visible rectangles for the component c
and all of its ancestors.  The return value is stored in
visibleRect.

Params:
  • c –  the component
  • visibleRect –  a Rectangle computed as the
         intersection of all visible rectangles for the component
         c and all of its ancestors -- this is the
         return value for this method
See Also:
/**
     * Returns the <code>Component</code>'s "visible rect rectangle" -  the
     * intersection of the visible rectangles for the component <code>c</code>
     * and all of its ancestors.  The return value is stored in
     * <code>visibleRect</code>.
     *
     * @param c  the component
     * @param visibleRect  a <code>Rectangle</code> computed as the
     *          intersection of all visible rectangles for the component
     *          <code>c</code> and all of its ancestors -- this is the
     *          return value for this method
     * @see #getVisibleRect
     */
    @SuppressWarnings("deprecation")
    static final void computeVisibleRect(Component c, Rectangle visibleRect) {
        Container p = c.getParent();
        Rectangle bounds = c.getBounds();

        if (p == null || p instanceof Window || p instanceof Applet) {
            visibleRect.setBounds(0, 0, bounds.width, bounds.height);
        } else {
            computeVisibleRect(p, visibleRect);
            visibleRect.x -= bounds.x;
            visibleRect.y -= bounds.y;
            SwingUtilities.computeIntersection(0,0,bounds.width,bounds.height,visibleRect);
        }
    }


    
Returns the Component's "visible rect rectangle" -  the
intersection of the visible rectangles for this component
and all of its ancestors.  The return value is stored in
visibleRect.

Params:
  • visibleRect – a Rectangle computed as the
         intersection of all visible rectangles for this
         component and all of its ancestors -- this is the return
         value for this method
See Also:
/**
     * Returns the <code>Component</code>'s "visible rect rectangle" -  the
     * intersection of the visible rectangles for this component
     * and all of its ancestors.  The return value is stored in
     * <code>visibleRect</code>.
     *
     * @param visibleRect a <code>Rectangle</code> computed as the
     *          intersection of all visible rectangles for this
     *          component and all of its ancestors -- this is the return
     *          value for this method
     * @see #getVisibleRect
     */
    public void computeVisibleRect(Rectangle visibleRect) {
        computeVisibleRect(this, visibleRect);
    }


    
Returns the Component's "visible rectangle" -  the
intersection of this component's visible rectangle,
new Rectangle(0, 0, getWidth(), getHeight()),
and all of its ancestors' visible rectangles.

Returns:the visible rectangle
/**
     * Returns the <code>Component</code>'s "visible rectangle" -  the
     * intersection of this component's visible rectangle,
     * <code>new Rectangle(0, 0, getWidth(), getHeight())</code>,
     * and all of its ancestors' visible rectangles.
     *
     * @return the visible rectangle
     */
    @BeanProperty(bound = false)
    public Rectangle getVisibleRect() {
        Rectangle visibleRect = new Rectangle();

        computeVisibleRect(visibleRect);
        return visibleRect;
    }

    
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
/**
     * 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
     */
    public void firePropertyChange(String propertyName,
                                   boolean oldValue, boolean newValue) {
        super.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
/**
     * 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
     */
    public void firePropertyChange(String propertyName,
                                      int oldValue, int newValue) {
        super.firePropertyChange(propertyName, oldValue, newValue);
    }

    // XXX This method is implemented as a workaround to a JLS issue with ambiguous
    // methods. This should be removed once 4758654 is resolved.
    public void firePropertyChange(String propertyName, char oldValue, char newValue) {
        super.firePropertyChange(propertyName, oldValue, newValue);
    }

    
Supports reporting constrained property changes.
This method can be called when a constrained property has changed
and it will send the appropriate PropertyChangeEvent
to any registered VetoableChangeListeners.

Params:
  • propertyName –  the name of the property that was listened on
  • oldValue –  the old value of the property
  • newValue –  the new value of the property
Throws:
/**
     * Supports reporting constrained property changes.
     * This method can be called when a constrained property has changed
     * and it will send the appropriate <code>PropertyChangeEvent</code>
     * to any registered <code>VetoableChangeListeners</code>.
     *
     * @param propertyName  the name of the property that was listened on
     * @param oldValue  the old value of the property
     * @param newValue  the new value of the property
     * @exception java.beans.PropertyVetoException when the attempt to set the
     *          property is vetoed by the component
     */
    protected void fireVetoableChange(String propertyName, Object oldValue, Object newValue)
        throws java.beans.PropertyVetoException
    {
        if (vetoableChangeSupport == null) {
            return;
        }
        vetoableChangeSupport.fireVetoableChange(propertyName, oldValue, newValue);
    }


    
Adds a VetoableChangeListener to the listener list.
The listener is registered for all properties.

Params:
  • listener –  the VetoableChangeListener to be added
/**
     * Adds a <code>VetoableChangeListener</code> to the listener list.
     * The listener is registered for all properties.
     *
     * @param listener  the <code>VetoableChangeListener</code> to be added
     */
    public synchronized void addVetoableChangeListener(VetoableChangeListener listener) {
        if (vetoableChangeSupport == null) {
            vetoableChangeSupport = new java.beans.VetoableChangeSupport(this);
        }
        vetoableChangeSupport.addVetoableChangeListener(listener);
    }


    
Removes a VetoableChangeListener from the listener list.
This removes a VetoableChangeListener that was registered
for all properties.

Params:
  • listener –  the VetoableChangeListener to be removed
/**
     * Removes a <code>VetoableChangeListener</code> from the listener list.
     * This removes a <code>VetoableChangeListener</code> that was registered
     * for all properties.
     *
     * @param listener  the <code>VetoableChangeListener</code> to be removed
     */
    public synchronized void removeVetoableChangeListener(VetoableChangeListener listener) {
        if (vetoableChangeSupport == null) {
            return;
        }
        vetoableChangeSupport.removeVetoableChangeListener(listener);
    }


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

See Also:
Returns:all of the component's VetoableChangeListeners
        or an empty
        array if no vetoable change listeners are currently registered
Since:1.4
/**
     * Returns an array of all the vetoable change listeners
     * registered on this component.
     *
     * @return all of the component's <code>VetoableChangeListener</code>s
     *         or an empty
     *         array if no vetoable change listeners are currently registered
     *
     * @see #addVetoableChangeListener
     * @see #removeVetoableChangeListener
     *
     * @since 1.4
     */
    @BeanProperty(bound = false)
    public synchronized VetoableChangeListener[] getVetoableChangeListeners() {
        if (vetoableChangeSupport == null) {
            return new VetoableChangeListener[0];
        }
        return vetoableChangeSupport.getVetoableChangeListeners();
    }


    
Returns the top-level ancestor of this component (either the
containing Window or Applet),
or null if this component has not
been added to any container.

Returns:the top-level Container that this component is in,
         or null if not in any container
/**
     * Returns the top-level ancestor of this component (either the
     * containing <code>Window</code> or <code>Applet</code>),
     * or <code>null</code> if this component has not
     * been added to any container.
     *
     * @return the top-level <code>Container</code> that this component is in,
     *          or <code>null</code> if not in any container
     */
    @BeanProperty(bound = false)
    @SuppressWarnings("deprecation")
    public Container getTopLevelAncestor() {
        for(Container p = this; p != null; p = p.getParent()) {
            if(p instanceof Window || p instanceof Applet) {
                return p;
            }
        }
        return null;
    }

    private AncestorNotifier getAncestorNotifier() {
        return (AncestorNotifier)
            getClientProperty(JComponent_ANCESTOR_NOTIFIER);
    }

    
Registers listener so that it will receive
AncestorEvents when it or any of its ancestors
move or are made visible or invisible.
Events are also sent when the component or its ancestors are added
or removed from the containment hierarchy.

Params:
  • listener –  the AncestorListener to register
See Also:
/**
     * Registers <code>listener</code> so that it will receive
     * <code>AncestorEvents</code> when it or any of its ancestors
     * move or are made visible or invisible.
     * Events are also sent when the component or its ancestors are added
     * or removed from the containment hierarchy.
     *
     * @param listener  the <code>AncestorListener</code> to register
     * @see AncestorEvent
     */
    public void addAncestorListener(AncestorListener listener) {
        AncestorNotifier ancestorNotifier = getAncestorNotifier();
        if (ancestorNotifier == null) {
            ancestorNotifier = new AncestorNotifier(this);
            putClientProperty(JComponent_ANCESTOR_NOTIFIER,
                              ancestorNotifier);
        }
        ancestorNotifier.addAncestorListener(listener);
    }

    
Unregisters listener so that it will no longer receive
AncestorEvents.

Params:
  • listener –  the AncestorListener to be removed
See Also:
/**
     * Unregisters <code>listener</code> so that it will no longer receive
     * <code>AncestorEvents</code>.
     *
     * @param listener  the <code>AncestorListener</code> to be removed
     * @see #addAncestorListener
     */
    public void removeAncestorListener(AncestorListener listener) {
        AncestorNotifier ancestorNotifier = getAncestorNotifier();
        if (ancestorNotifier == null) {
            return;
        }
        ancestorNotifier.removeAncestorListener(listener);
        if (ancestorNotifier.listenerList.getListenerList().length == 0) {
            ancestorNotifier.removeAllListeners();
            putClientProperty(JComponent_ANCESTOR_NOTIFIER, null);
        }
    }

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

See Also:
Returns:all of the component's AncestorListeners
        or an empty
        array if no ancestor listeners are currently registered
Since:1.4
/**
     * Returns an array of all the ancestor listeners
     * registered on this component.
     *
     * @return all of the component's <code>AncestorListener</code>s
     *         or an empty
     *         array if no ancestor listeners are currently registered
     *
     * @see #addAncestorListener
     * @see #removeAncestorListener
     *
     * @since 1.4
     */
    @BeanProperty(bound = false)
    public AncestorListener[] getAncestorListeners() {
        AncestorNotifier ancestorNotifier = getAncestorNotifier();
        if (ancestorNotifier == null) {
            return new AncestorListener[0];
        }
        return ancestorNotifier.getAncestorListeners();
    }

    
Returns an array of all the objects currently registered
as FooListeners
upon this JComponent.
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
JComponent 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
Throws:
  • ClassCastException – if listenerType
         doesn't specify a class or interface that implements
         java.util.EventListener
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>JComponent</code>.
     * <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</code> argument
     * with a class literal,
     * such as
     * <code><em>Foo</em>Listener.class</code>.
     * For example, you can query a
     * <code>JComponent</code> <code>c</code>
     * 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 listenerType the type of listeners requested; this parameter
     *          should specify an interface that descends from
     *          <code>java.util.EventListener</code>
     * @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</code>
     *          doesn't specify a class or interface that implements
     *          <code>java.util.EventListener</code>
     *
     * @since 1.3
     *
     * @see #getVetoableChangeListeners
     * @see #getAncestorListeners
     */
    @SuppressWarnings("unchecked") // Casts to (T[])
    public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
        T[] result;
        if (listenerType == AncestorListener.class) {
            // AncestorListeners are handled by the AncestorNotifier
            result = (T[])getAncestorListeners();
        }
        else if (listenerType == VetoableChangeListener.class) {
            // VetoableChangeListeners are handled by VetoableChangeSupport
            result = (T[])getVetoableChangeListeners();
        }
        else if (listenerType == PropertyChangeListener.class) {
            // PropertyChangeListeners are handled by PropertyChangeSupport
            result = (T[])getPropertyChangeListeners();
        }
        else {
            result = listenerList.getListeners(listenerType);
        }

        if (result.length == 0) {
            return super.getListeners(listenerType);
        }
        return result;
    }

    
Notifies this component that it now has a parent component.
When this method is invoked, the chain of parent components is
set up with KeyboardAction event listeners.
This method is called by the toolkit internally and should
not be called directly by programs.

See Also:
  • registerKeyboardAction
/**
     * Notifies this component that it now has a parent component.
     * When this method is invoked, the chain of parent components is
     * set up with <code>KeyboardAction</code> event listeners.
     * This method is called by the toolkit internally and should
     * not be called directly by programs.
     *
     * @see #registerKeyboardAction
     */
    public void addNotify() {
        super.addNotify();
        firePropertyChange("ancestor", null, getParent());

        registerWithKeyboardManager(false);
        registerNextFocusableComponent();
    }


    
Notifies this component that it no longer has a parent component.
When this method is invoked, any KeyboardActions
set up in the chain of parent components are removed.
This method is called by the toolkit internally and should
not be called directly by programs.

See Also:
  • registerKeyboardAction
/**
     * Notifies this component that it no longer has a parent component.
     * When this method is invoked, any <code>KeyboardAction</code>s
     * set up in the chain of parent components are removed.
     * This method is called by the toolkit internally and should
     * not be called directly by programs.
     *
     * @see #registerKeyboardAction
     */
    public void removeNotify() {
        super.removeNotify();
        // This isn't strictly correct.  The event shouldn't be
        // fired until *after* the parent is set to null.  But
        // we only get notified before that happens
        firePropertyChange("ancestor", getParent(), null);

        unregisterWithKeyboardManager();
        deregisterNextFocusableComponent();

        if (getCreatedDoubleBuffer()) {
            RepaintManager.currentManager(this).resetDoubleBuffer();
            setCreatedDoubleBuffer(false);
        }
        if (autoscrolls) {
            Autoscroller.stop(this);
        }
    }


    
Adds the specified region to the dirty region list if the component
is showing.  The component will be repainted after all of the
currently pending events have been dispatched.

Params:
  • tm –  this parameter is not used
  • x –  the x value of the dirty region
  • y –  the y value of the dirty region
  • width –  the width of the dirty region
  • height –  the height of the dirty region
See Also:
/**
     * Adds the specified region to the dirty region list if the component
     * is showing.  The component will be repainted after all of the
     * currently pending events have been dispatched.
     *
     * @param tm  this parameter is not used
     * @param x  the x value of the dirty region
     * @param y  the y value of the dirty region
     * @param width  the width of the dirty region
     * @param height  the height of the dirty region
     * @see #isPaintingOrigin()
     * @see java.awt.Component#isShowing
     * @see RepaintManager#addDirtyRegion
     */
    public void repaint(long tm, int x, int y, int width, int height) {
        RepaintManager.currentManager(SunToolkit.targetToAppContext(this))
                      .addDirtyRegion(this, x, y, width, height);
    }


    
Adds the specified region to the dirty region list if the component
is showing.  The component will be repainted after all of the
currently pending events have been dispatched.

Params:
  • r – a Rectangle containing the dirty region
See Also:
/**
     * Adds the specified region to the dirty region list if the component
     * is showing.  The component will be repainted after all of the
     * currently pending events have been dispatched.
     *
     * @param  r a <code>Rectangle</code> containing the dirty region
     * @see #isPaintingOrigin()
     * @see java.awt.Component#isShowing
     * @see RepaintManager#addDirtyRegion
     */
    public void repaint(Rectangle r) {
        repaint(0,r.x,r.y,r.width,r.height);
    }


    
Supports deferred automatic layout.


Calls invalidate and then adds this component's
validateRoot to a list of components that need to be
validated.  Validation will occur after all currently pending
events have been dispatched.  In other words after this method
is called,  the first validateRoot (if any) found when walking
up the containment hierarchy of this component will be validated.
By default, JRootPane, JScrollPane,
and JTextField return true
from isValidateRoot.


This method will automatically be called on this component
when a property value changes such that size, location, or
internal layout of this component has been affected.  This automatic
updating differs from the AWT because programs generally no
longer need to invoke validate to get the contents of the
GUI to update.

See Also:
/**
     * Supports deferred automatic layout.
     * <p>
     * Calls <code>invalidate</code> and then adds this component's
     * <code>validateRoot</code> to a list of components that need to be
     * validated.  Validation will occur after all currently pending
     * events have been dispatched.  In other words after this method
     * is called,  the first validateRoot (if any) found when walking
     * up the containment hierarchy of this component will be validated.
     * By default, <code>JRootPane</code>, <code>JScrollPane</code>,
     * and <code>JTextField</code> return true
     * from <code>isValidateRoot</code>.
     * <p>
     * This method will automatically be called on this component
     * when a property value changes such that size, location, or
     * internal layout of this component has been affected.  This automatic
     * updating differs from the AWT because programs generally no
     * longer need to invoke <code>validate</code> to get the contents of the
     * GUI to update.
     *
     * @see java.awt.Component#invalidate
     * @see java.awt.Container#validate
     * @see #isValidateRoot
     * @see RepaintManager#addInvalidComponent
     */
    public void revalidate() {
        if (getParent() == null) {
            // Note: We don't bother invalidating here as once added
            // to a valid parent invalidate will be invoked (addImpl
            // invokes addNotify which will invoke invalidate on the
            // new Component). Also, if we do add a check to isValid
            // here it can potentially be called before the constructor
            // which was causing some people grief.
            return;
        }
        if (SunToolkit.isDispatchThreadForAppContext(this)) {
            invalidate();
            RepaintManager.currentManager(this).addInvalidComponent(this);
        }
        else {
            // To avoid a flood of Runnables when constructing GUIs off
            // the EDT, a flag is maintained as to whether or not
            // a Runnable has been scheduled.
            if (revalidateRunnableScheduled.getAndSet(true)) {
                return;
            }
            SunToolkit.executeOnEventHandlerThread(this, () -> {
                revalidateRunnableScheduled.set(false);
                revalidate();
            });
        }
    }

    
If this method returns true, revalidate calls by
descendants of this component will cause the entire tree
beginning with this root to be validated.
Returns false by default.  JScrollPane overrides
this method and returns true.

See Also:
Returns:always returns false
/**
     * If this method returns true, <code>revalidate</code> calls by
     * descendants of this component will cause the entire tree
     * beginning with this root to be validated.
     * Returns false by default.  <code>JScrollPane</code> overrides
     * this method and returns true.
     *
     * @return always returns false
     * @see #revalidate
     * @see java.awt.Component#invalidate
     * @see java.awt.Container#validate
     * @see java.awt.Container#isValidateRoot
     */
    @Override
    public boolean isValidateRoot() {
        return false;
    }


    
Returns true if this component tiles its children -- that is, if
it can guarantee that the children will not overlap.  The
repainting system is substantially more efficient in this
common case.  JComponent subclasses that can't make this
guarantee, such as JLayeredPane,
should override this method to return false.

Returns:always returns true
/**
     * Returns true if this component tiles its children -- that is, if
     * it can guarantee that the children will not overlap.  The
     * repainting system is substantially more efficient in this
     * common case.  <code>JComponent</code> subclasses that can't make this
     * guarantee, such as <code>JLayeredPane</code>,
     * should override this method to return false.
     *
     * @return always returns true
     */
    @BeanProperty(bound = false)
    public boolean isOptimizedDrawingEnabled() {
        return true;
    }

    
Returns true if a paint triggered on a child component should cause painting to originate from this Component, or one of its ancestors. 
 Calling Component.repaint or paintImmediately(int, int, int, int) on a Swing component will result in calling the paintImmediately(int, int, int, int) method of the first ancestor which isPaintingOrigin() returns true, if there are any. 
 JComponent subclasses that need to be painted when any of their children are repainted should override this method to return true. 
See Also:
Returns:always returns false
/**
     * Returns {@code true} if a paint triggered on a child component should cause
     * painting to originate from this Component, or one of its ancestors.
     * <p>
     * Calling {@link #repaint} or {@link #paintImmediately(int, int, int, int)}
     * on a Swing component will result in calling
     * the {@link JComponent#paintImmediately(int, int, int, int)} method of
     * the first ancestor which {@code isPaintingOrigin()} returns {@code true}, if there are any.
     * <p>
     * {@code JComponent} subclasses that need to be painted when any of their
     * children are repainted should override this method to return {@code true}.
     *
     * @return always returns {@code false}
     *
     * @see #paintImmediately(int, int, int, int)
     */
    protected boolean isPaintingOrigin() {
        return false;
    }

    
Paints the specified region in this component and all of its
descendants that overlap the region, immediately.


It's rarely necessary to call this method.  In most cases it's
more efficient to call repaint, which defers the actual painting
and can collapse redundant requests into a single paint call.
This method is useful if one needs to update the display while
the current event is being dispatched.


This method is to be overridden when the dirty region needs to be changed
for components that are painting origins.

Params:
  • x –  the x value of the region to be painted
  • y –  the y value of the region to be painted
  • w –  the width of the region to be painted
  • h –  the height of the region to be painted
See Also:
/**
     * Paints the specified region in this component and all of its
     * descendants that overlap the region, immediately.
     * <p>
     * It's rarely necessary to call this method.  In most cases it's
     * more efficient to call repaint, which defers the actual painting
     * and can collapse redundant requests into a single paint call.
     * This method is useful if one needs to update the display while
     * the current event is being dispatched.
     * <p>
     * This method is to be overridden when the dirty region needs to be changed
     * for components that are painting origins.
     *
     * @param x  the x value of the region to be painted
     * @param y  the y value of the region to be painted
     * @param w  the width of the region to be painted
     * @param h  the height of the region to be painted
     * @see #repaint
     * @see #isPaintingOrigin()
     */
    public void paintImmediately(int x,int y,int w, int h) {
        Component c = this;
        Component parent;

        if(!isShowing()) {
            return;
        }

        JComponent paintingOigin = SwingUtilities.getPaintingOrigin(this);
        if (paintingOigin != null) {
            Rectangle rectangle = SwingUtilities.convertRectangle(
                    c, new Rectangle(x, y, w, h), paintingOigin);
            paintingOigin.paintImmediately(rectangle.x, rectangle.y, rectangle.width, rectangle.height);
            return;
        }

        while(!c.isOpaque()) {
            parent = c.getParent();
            if(parent != null) {
                x += c.getX();
                y += c.getY();
                c = parent;
            } else {
                break;
            }

            if(!(c instanceof JComponent)) {
                break;
            }
        }
        if(c instanceof JComponent) {
            ((JComponent)c)._paintImmediately(x,y,w,h);
        } else {
            c.repaint(x,y,w,h);
        }
    }

    
Paints the specified region now.

Params:
  • r – a Rectangle containing the region to be painted
/**
     * Paints the specified region now.
     *
     * @param r a <code>Rectangle</code> containing the region to be painted
     */
    public void paintImmediately(Rectangle r) {
        paintImmediately(r.x,r.y,r.width,r.height);
    }

    
Returns whether this component should be guaranteed to be on top.
For example, it would make no sense for Menus to pop up
under another component, so they would always return true.
Most components will want to return false, hence that is the default.

Returns:always returns false
/**
     * Returns whether this component should be guaranteed to be on top.
     * For example, it would make no sense for <code>Menu</code>s to pop up
     * under another component, so they would always return true.
     * Most components will want to return false, hence that is the default.
     *
     * @return always returns false
     */
    // package private
    boolean alwaysOnTop() {
        return false;
    }

    void setPaintingChild(Component paintingChild) {
        this.paintingChild = paintingChild;
    }

    @SuppressWarnings("deprecation")
    void _paintImmediately(int x, int y, int w, int h) {
        Graphics g;
        Container c;
        Rectangle b;

        int tmpX, tmpY, tmpWidth, tmpHeight;
        int offsetX=0,offsetY=0;

        boolean hasBuffer = false;

        JComponent bufferedComponent = null;
        JComponent paintingComponent = this;

        RepaintManager repaintManager = RepaintManager.currentManager(this);
        // parent Container's up to Window or Applet. First container is
        // the direct parent. Note that in testing it was faster to
        // alloc a new Vector vs keeping a stack of them around, and gc
        // seemed to have a minimal effect on this.
        java.util.List<Component> path = new java.util.ArrayList<Component>(7);
        int pIndex = -1;
        int pCount = 0;

        tmpX = tmpY = tmpWidth = tmpHeight = 0;

        Rectangle paintImmediatelyClip = fetchRectangle();
        paintImmediatelyClip.x = x;
        paintImmediatelyClip.y = y;
        paintImmediatelyClip.width = w;
        paintImmediatelyClip.height = h;


        // System.out.println("1) ************* in _paintImmediately for " + this);

        boolean ontop = alwaysOnTop() && isOpaque();
        if (ontop) {
            SwingUtilities.computeIntersection(0, 0, getWidth(), getHeight(),
                                               paintImmediatelyClip);
            if (paintImmediatelyClip.width == 0) {
                recycleRectangle(paintImmediatelyClip);
                return;
            }
        }
        Component child;
        for (c = this, child = null;
             c != null && !(c instanceof Window) && !(c instanceof Applet);
             child = c, c = c.getParent()) {
                JComponent jc = (c instanceof JComponent) ? (JComponent)c :
                                null;
                path.add(c);
                if(!ontop && jc != null && !jc.isOptimizedDrawingEnabled()) {
                    boolean resetPC;

                    // Children of c may overlap, three possible cases for the
                    // painting region:
                    // . Completely obscured by an opaque sibling, in which
                    //   case there is no need to paint.
                    // . Partially obscured by a sibling: need to start
                    //   painting from c.
                    // . Otherwise we aren't obscured and thus don't need to
                    //   start painting from parent.
                    if (c != this) {
                        if (jc.isPaintingOrigin()) {
                            resetPC = true;
                        }
                        else {
                            Component[] children = c.getComponents();
                            int i = 0;
                            for (; i<children.length; i++) {
                                if (children[i] == child) break;
                            }
                            switch (jc.getObscuredState(i,
                                            paintImmediatelyClip.x,
                                            paintImmediatelyClip.y,
                                            paintImmediatelyClip.width,
                                            paintImmediatelyClip.height)) {
                            case NOT_OBSCURED:
                                resetPC = false;
                                break;
                            case COMPLETELY_OBSCURED:
                                recycleRectangle(paintImmediatelyClip);
                                return;
                            default:
                                resetPC = true;
                                break;
                            }
                        }
                    }
                    else {
                        resetPC = false;
                    }

                    if (resetPC) {
                        // Get rid of any buffer since we draw from here and
                        // we might draw something larger
                        paintingComponent = jc;
                        pIndex = pCount;
                        offsetX = offsetY = 0;
                        hasBuffer = false;
                    }
                }
                pCount++;

                // look to see if the parent (and therefor this component)
                // is double buffered
                if(repaintManager.isDoubleBufferingEnabled() && jc != null &&
                                  jc.isDoubleBuffered()) {
                    hasBuffer = true;
                    bufferedComponent = jc;
                }

                // if we aren't on top, include the parent's clip
                if (!ontop) {
                    int bx = c.getX();
                    int by = c.getY();
                    tmpWidth = c.getWidth();
                    tmpHeight = c.getHeight();
                    SwingUtilities.computeIntersection(tmpX,tmpY,tmpWidth,tmpHeight,paintImmediatelyClip);
                    paintImmediatelyClip.x += bx;
                    paintImmediatelyClip.y += by;
                    offsetX += bx;
                    offsetY += by;
                }
        }

        // If the clip width or height is negative, don't bother painting
        if(c == null || !c.isDisplayable() ||
                        paintImmediatelyClip.width <= 0 ||
                        paintImmediatelyClip.height <= 0) {
            recycleRectangle(paintImmediatelyClip);
            return;
        }

        paintingComponent.setFlag(IS_REPAINTING, true);

        paintImmediatelyClip.x -= offsetX;
        paintImmediatelyClip.y -= offsetY;

        // Notify the Components that are going to be painted of the
        // child component to paint to.
        if(paintingComponent != this) {
            Component comp;
            int i = pIndex;
            for(; i > 0 ; i--) {
                comp = path.get(i);
                if(comp instanceof JComponent) {
                    ((JComponent)comp).setPaintingChild(path.get(i-1));
                }
            }
        }
        try {
            if ((g = safelyGetGraphics(paintingComponent, c)) != null) {
                try {
                    if (hasBuffer) {
                        RepaintManager rm = RepaintManager.currentManager(
                                bufferedComponent);
                        rm.beginPaint();
                        try {
                            rm.paint(paintingComponent, bufferedComponent, g,
                                    paintImmediatelyClip.x,
                                    paintImmediatelyClip.y,
                                    paintImmediatelyClip.width,
                                    paintImmediatelyClip.height);
                        } finally {
                            rm.endPaint();
                        }
                    } else {
                        g.setClip(paintImmediatelyClip.x, paintImmediatelyClip.y,
                                paintImmediatelyClip.width, paintImmediatelyClip.height);
                        paintingComponent.paint(g);
                    }
                } finally {
                    g.dispose();
                }
            }
        }
        finally {
            // Reset the painting child for the parent components.
            if(paintingComponent != this) {
                Component comp;
                int i = pIndex;
                for(; i > 0 ; i--) {
                    comp = path.get(i);
                    if(comp instanceof JComponent) {
                        ((JComponent)comp).setPaintingChild(null);
                    }
                }
            }
            paintingComponent.setFlag(IS_REPAINTING, false);
        }
        recycleRectangle(paintImmediatelyClip);
    }

    
Paints to the specified graphics.  This does not set the clip and it
does not adjust the Graphics in anyway, callers must do that first.
This method is package-private for RepaintManager.PaintManager and
its subclasses to call, it is NOT intended for general use outside
of that.

/**
     * Paints to the specified graphics.  This does not set the clip and it
     * does not adjust the Graphics in anyway, callers must do that first.
     * This method is package-private for RepaintManager.PaintManager and
     * its subclasses to call, it is NOT intended for general use outside
     * of that.
     */
    void paintToOffscreen(Graphics g, int x, int y, int w, int h, int maxX,
                          int maxY) {
        try {
            setFlag(ANCESTOR_USING_BUFFER, true);
            if ((y + h) < maxY || (x + w) < maxX) {
                setFlag(IS_PAINTING_TILE, true);
            }
            if (getFlag(IS_REPAINTING)) {
                // Called from paintImmediately (RepaintManager) to fill
                // repaint request
                paint(g);
            } else {
                // Called from paint() (AWT) to repair damage
                if(!rectangleIsObscured(x, y, w, h)) {
                    paintComponent(g);
                    paintBorder(g);
                }
                paintChildren(g);
            }
        } finally {
            setFlag(ANCESTOR_USING_BUFFER, false);
            setFlag(IS_PAINTING_TILE, false);
        }
    }

    
Returns whether or not the region of the specified component is
obscured by a sibling.

Returns:NOT_OBSCURED if non of the siblings above the Component obscure
        it, COMPLETELY_OBSCURED if one of the siblings completely
        obscures the Component or PARTIALLY_OBSCURED if the Component is
        only partially obscured.
/**
     * Returns whether or not the region of the specified component is
     * obscured by a sibling.
     *
     * @return NOT_OBSCURED if non of the siblings above the Component obscure
     *         it, COMPLETELY_OBSCURED if one of the siblings completely
     *         obscures the Component or PARTIALLY_OBSCURED if the Component is
     *         only partially obscured.
     */
    private int getObscuredState(int compIndex, int x, int y, int width,
                                 int height) {
        int retValue = NOT_OBSCURED;
        Rectangle tmpRect = fetchRectangle();

        for (int i = compIndex - 1 ; i >= 0 ; i--) {
            Component sibling = getComponent(i);
            if (!sibling.isVisible()) {
                continue;
            }
            Rectangle siblingRect;
            boolean opaque;
            if (sibling instanceof JComponent) {
                opaque = sibling.isOpaque();
                if (!opaque) {
                    if (retValue == PARTIALLY_OBSCURED) {
                        continue;
                    }
                }
            }
            else {
                opaque = true;
            }
            siblingRect = sibling.getBounds(tmpRect);
            if (opaque && x >= siblingRect.x && (x + width) <=
                     (siblingRect.x + siblingRect.width) &&
                     y >= siblingRect.y && (y + height) <=
                     (siblingRect.y + siblingRect.height)) {
                recycleRectangle(tmpRect);
                return COMPLETELY_OBSCURED;
            }
            else if (retValue == NOT_OBSCURED &&
                     !((x + width <= siblingRect.x) ||
                       (y + height <= siblingRect.y) ||
                       (x >= siblingRect.x + siblingRect.width) ||
                       (y >= siblingRect.y + siblingRect.height))) {
                retValue = PARTIALLY_OBSCURED;
            }
        }
        recycleRectangle(tmpRect);
        return retValue;
    }

    
Returns true, which implies that before checking if a child should
be painted it is first check that the child is not obscured by another
sibling. This is only checked if isOptimizedDrawingEnabled
returns false.

Returns:always returns true
/**
     * Returns true, which implies that before checking if a child should
     * be painted it is first check that the child is not obscured by another
     * sibling. This is only checked if <code>isOptimizedDrawingEnabled</code>
     * returns false.
     *
     * @return always returns true
     */
    boolean checkIfChildObscuredBySibling() {
        return true;
    }


    private void setFlag(int aFlag, boolean aValue) {
        if(aValue) {
            flags |= (1 << aFlag);
        } else {
            flags &= ~(1 << aFlag);
        }
    }
    private boolean getFlag(int aFlag) {
        int mask = (1 << aFlag);
        return ((flags & mask) == mask);
    }
    // These functions must be static so that they can be called from
    // subclasses inside the package, but whose inheritance hierarhcy includes
    // classes outside of the package below JComponent (e.g., JTextArea).
    static void setWriteObjCounter(JComponent comp, byte count) {
        comp.flags = (comp.flags & ~(0xFF << WRITE_OBJ_COUNTER_FIRST)) |
                     (count << WRITE_OBJ_COUNTER_FIRST);
    }
    static byte getWriteObjCounter(JComponent comp) {
        return (byte)((comp.flags >> WRITE_OBJ_COUNTER_FIRST) & 0xFF);
    }

    /** Buffering **/

    
 Sets whether this component should use a buffer to paint.
 If set to true, all the drawing from this component will be done
 in an offscreen painting buffer. The offscreen painting buffer will
 the be copied onto the screen.
 If a Component is buffered and one of its ancestor
 is also buffered, the ancestor buffer will be used.
 @param aFlag if true, set this component to be double buffered

/**
     *  Sets whether this component should use a buffer to paint.
     *  If set to true, all the drawing from this component will be done
     *  in an offscreen painting buffer. The offscreen painting buffer will
     *  the be copied onto the screen.
     *  If a <code>Component</code> is buffered and one of its ancestor
     *  is also buffered, the ancestor buffer will be used.
     *
     *  @param aFlag if true, set this component to be double buffered
     */
    public void setDoubleBuffered(boolean aFlag) {
        setFlag(IS_DOUBLE_BUFFERED,aFlag);
    }

    
Returns whether this component should use a buffer to paint.

Returns:true if this component is double buffered, otherwise false
/**
     * Returns whether this component should use a buffer to paint.
     *
     * @return true if this component is double buffered, otherwise false
     */
    public boolean isDoubleBuffered() {
        return getFlag(IS_DOUBLE_BUFFERED);
    }

    
Returns the JRootPane ancestor for this component.

Returns:the JRootPane that contains this component,
         or null if no JRootPane is found
/**
     * Returns the <code>JRootPane</code> ancestor for this component.
     *
     * @return the <code>JRootPane</code> that contains this component,
     *          or <code>null</code> if no <code>JRootPane</code> is found
     */
    @BeanProperty(bound = false)
    public JRootPane getRootPane() {
        return SwingUtilities.getRootPane(this);
    }


    /** Serialization **/

    
This is called from Component by way of reflection. Do NOT change
the name unless you change the code in Component as well.

/**
     * This is called from Component by way of reflection. Do NOT change
     * the name unless you change the code in Component as well.
     */
    void compWriteObjectNotify() {
        byte count = JComponent.getWriteObjCounter(this);
        JComponent.setWriteObjCounter(this, (byte)(count + 1));
        if (count != 0) {
            return;
        }

        uninstallUIAndProperties();

        /* JTableHeader is in a separate package, which prevents it from
         * being able to override this package-private method the way the
         * other components can.  We don't want to make this method protected
         * because it would introduce public-api for a less-than-desirable
         * serialization scheme, so we compromise with this 'instanceof' hack
         * for now.
         */
        if (getToolTipText() != null ||
            this instanceof javax.swing.table.JTableHeader) {
            ToolTipManager.sharedInstance().unregisterComponent(JComponent.this);
        }
    }

    
This object is the ObjectInputStream callback
that's called after a complete graph of objects (including at least
one JComponent) has been read.
 It sets the UI property of each Swing component
that was read to the current default with updateUI.


As each  component is read in we keep track of the current set of
root components here, in the roots vector.  Note that there's only one
ReadObjectCallback per ObjectInputStream,
they're stored in the static readObjectCallbacks
hashtable.

See Also:
/**
     * This object is the <code>ObjectInputStream</code> callback
     * that's called after a complete graph of objects (including at least
     * one <code>JComponent</code>) has been read.
     *  It sets the UI property of each Swing component
     * that was read to the current default with <code>updateUI</code>.
     * <p>
     * As each  component is read in we keep track of the current set of
     * root components here, in the roots vector.  Note that there's only one
     * <code>ReadObjectCallback</code> per <code>ObjectInputStream</code>,
     * they're stored in the static <code>readObjectCallbacks</code>
     * hashtable.
     *
     * @see java.io.ObjectInputStream#registerValidation
     * @see SwingUtilities#updateComponentTreeUI
     */
    private class ReadObjectCallback implements ObjectInputValidation
    {
        private final Vector<JComponent> roots = new Vector<JComponent>(1);
        private final ObjectInputStream inputStream;

        ReadObjectCallback(ObjectInputStream s) throws Exception {
            inputStream = s;
            s.registerValidation(this, 0);
        }

        
This is the method that's called after the entire graph
of objects has been read in.  It initializes
the UI property of all of the copmonents with
SwingUtilities.updateComponentTreeUI.

/**
         * This is the method that's called after the entire graph
         * of objects has been read in.  It initializes
         * the UI property of all of the copmonents with
         * <code>SwingUtilities.updateComponentTreeUI</code>.
         */
        public void validateObject() throws InvalidObjectException {
            try {
                for (JComponent root : roots) {
                    SwingUtilities.updateComponentTreeUI(root);
                }
            }
            finally {
                readObjectCallbacks.remove(inputStream);
            }
        }

        
If c isn't a descendant of a component we've already
seen, then add it to the roots Vector.

Params:
  • c – the JComponent to add
/**
         * If <code>c</code> isn't a descendant of a component we've already
         * seen, then add it to the roots <code>Vector</code>.
         *
         * @param c the <code>JComponent</code> to add
         */
        private void registerComponent(JComponent c)
        {
            /* If the Component c is a descendant of one of the
             * existing roots (or it IS an existing root), we're done.
             */
            for (JComponent root : roots) {
                for(Component p = c; p != null; p = p.getParent()) {
                    if (p == root) {
                        return;
                    }
                }
            }

            /* Otherwise: if Component c is an ancestor of any of the
             * existing roots then remove them and add c (the "new root")
             * to the roots vector.
             */
            for(int i = 0; i < roots.size(); i++) {
                JComponent root = roots.elementAt(i);
                for(Component p = root.getParent(); p != null; p = p.getParent()) {
                    if (p == c) {
                        roots.removeElementAt(i--); // !!
                        break;
                    }
                }
            }

            roots.addElement(c);
        }
    }


    
We use the ObjectInputStream "registerValidation"
callback to update the UI for the entire tree of components
after they've all been read in.

Params:
  • s –  the ObjectInputStream from which to read
/**
     * We use the <code>ObjectInputStream</code> "registerValidation"
     * callback to update the UI for the entire tree of components
     * after they've all been read in.
     *
     * @param s  the <code>ObjectInputStream</code> from which to read
     */
    private void readObject(ObjectInputStream s)
        throws IOException, ClassNotFoundException
    {
        ObjectInputStream.GetField f = s.readFields();

        isAlignmentXSet = f.get("isAlignmentXSet", false);
        alignmentX = validateAlignment(f.get("alignmentX", 0f));
        isAlignmentYSet = f.get("isAlignmentYSet", false);
        alignmentY = validateAlignment(f.get("alignmentY", 0f));
        listenerList = (EventListenerList) f.get("listenerList", null);
        vetoableChangeSupport = (VetoableChangeSupport) f.get("vetoableChangeSupport", null);
        autoscrolls = f.get("autoscrolls", false);
        border = (Border) f.get("border", null);
        flags = f.get("flags", 0);
        inputVerifier = (InputVerifier) f.get("inputVerifier", null);
        verifyInputWhenFocusTarget = f.get("verifyInputWhenFocusTarget", false);
        popupMenu = (JPopupMenu) f.get("popupMenu", null);
        focusInputMap = (InputMap) f.get("focusInputMap", null);
        ancestorInputMap = (InputMap) f.get("ancestorInputMap", null);
        windowInputMap = (ComponentInputMap) f.get("windowInputMap", null);
        actionMap = (ActionMap) f.get("actionMap", null);

        /* If there's no ReadObjectCallback for this stream yet, that is, if
         * this is the first call to JComponent.readObject() for this
         * graph of objects, then create a callback and stash it
         * in the readObjectCallbacks table.  Note that the ReadObjectCallback
         * constructor takes care of calling s.registerValidation().
         */
        ReadObjectCallback cb = readObjectCallbacks.get(s);
        if (cb == null) {
            try {
                readObjectCallbacks.put(s, cb = new ReadObjectCallback(s));
            }
            catch (Exception e) {
                throw new IOException(e.toString());
            }
        }
        cb.registerComponent(this);

        // Read back the client properties.
        int cpCount = s.readInt();
        if (cpCount > 0) {
            clientProperties = new ArrayTable();
            for (int counter = 0; counter < cpCount; counter++) {
                clientProperties.put(s.readObject(),
                                     s.readObject());
            }
        }
        if (getToolTipText() != null) {
            ToolTipManager.sharedInstance().registerComponent(this);
        }
        setWriteObjCounter(this, (byte)0);
        revalidateRunnableScheduled = new AtomicBoolean(false);
    }


    
Before writing a JComponent to an
ObjectOutputStream we temporarily uninstall its UI.
This is tricky to do because we want to uninstall
the UI before any of the JComponent's children
(or its LayoutManager etc.) are written,
and we don't want to restore the UI until the most derived
JComponent subclass has been stored.

Params:
  • s – the ObjectOutputStream in which to write
/**
     * Before writing a <code>JComponent</code> to an
     * <code>ObjectOutputStream</code> we temporarily uninstall its UI.
     * This is tricky to do because we want to uninstall
     * the UI before any of the <code>JComponent</code>'s children
     * (or its <code>LayoutManager</code> etc.) are written,
     * and we don't want to restore the UI until the most derived
     * <code>JComponent</code> subclass has been stored.
     *
     * @param s the <code>ObjectOutputStream</code> in which to write
     */
    private void writeObject(ObjectOutputStream s) throws IOException {
        s.defaultWriteObject();
        if (getUIClassID().equals(uiClassID)) {
            byte count = JComponent.getWriteObjCounter(this);
            JComponent.setWriteObjCounter(this, --count);
            if (count == 0 && ui != null) {
                ui.installUI(this);
            }
        }
        ArrayTable.writeArrayTable(s, clientProperties);
    }


    
Returns a string representation of this JComponent.
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 JComponent
/**
     * Returns a string representation of this <code>JComponent</code>.
     * 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</code>.
     *
     * @return  a string representation of this <code>JComponent</code>
     */
    protected String paramString() {
        String preferredSizeString = (isPreferredSizeSet() ?
                                      getPreferredSize().toString() : "");
        String minimumSizeString = (isMinimumSizeSet() ?
                                    getMinimumSize().toString() : "");
        String maximumSizeString = (isMaximumSizeSet() ?
                                    getMaximumSize().toString() : "");
        String borderString = (border == null ? ""
                               : (border == this ? "this" : border.toString()));

        return super.paramString() +
        ",alignmentX=" + alignmentX +
        ",alignmentY=" + alignmentY +
        ",border=" + borderString +
        ",flags=" + flags +             // should beef this up a bit
        ",maximumSize=" + maximumSizeString +
        ",minimumSize=" + minimumSizeString +
        ",preferredSize=" + preferredSizeString;
    }

    
{@inheritDoc}

/**
     * {@inheritDoc}
     */
    @Override
    @Deprecated
    public void hide() {
        boolean showing = isShowing();
        super.hide();
        if (showing) {
            Container parent = getParent();
            if (parent != null) {
                Rectangle r = getBounds();
                parent.repaint(r.x, r.y, r.width, r.height);
            }
            revalidate();
        }
    }

}