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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
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 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package java.awt.event;

import java.awt.Event;
import java.awt.Component;
import java.awt.GraphicsEnvironment;
import java.awt.Toolkit;
import java.util.logging.Logger;
import java.util.logging.Level;


The root event class for all component-level input events.
Input events are delivered to listeners before they are
processed normally by the source where they originated.
This allows listeners and component subclasses to "consume"
the event so that the source will not process them in their
default manner.  For example, consuming mousePressed events
on a Button component will prevent the Button from being
activated.

Author:Carl Quinn
See Also:
Since:1.1
/**
 * The root event class for all component-level input events.
 *
 * Input events are delivered to listeners before they are
 * processed normally by the source where they originated.
 * This allows listeners and component subclasses to "consume"
 * the event so that the source will not process them in their
 * default manner.  For example, consuming mousePressed events
 * on a Button component will prevent the Button from being
 * activated.
 *
 * @author Carl Quinn
 *
 * @see KeyEvent
 * @see KeyAdapter
 * @see MouseEvent
 * @see MouseAdapter
 * @see MouseMotionAdapter
 *
 * @since 1.1
 */
public abstract class InputEvent extends ComponentEvent {
    private static final Logger log = Logger.getLogger("java.awt.event.InputEvent");

    
The Shift key modifier constant.
It is recommended that SHIFT_DOWN_MASK be used instead.

/**
     * The Shift key modifier constant.
     * It is recommended that SHIFT_DOWN_MASK be used instead.
     */
    public static final int SHIFT_MASK = Event.SHIFT_MASK;

    
The Control key modifier constant.
It is recommended that CTRL_DOWN_MASK be used instead.

/**
     * The Control key modifier constant.
     * It is recommended that CTRL_DOWN_MASK be used instead.
     */
    public static final int CTRL_MASK = Event.CTRL_MASK;

    
The Meta key modifier constant.
It is recommended that META_DOWN_MASK be used instead.

/**
     * The Meta key modifier constant.
     * It is recommended that META_DOWN_MASK be used instead.
     */
    public static final int META_MASK = Event.META_MASK;

    
The Alt key modifier constant.
It is recommended that ALT_DOWN_MASK be used instead.

/**
     * The Alt key modifier constant.
     * It is recommended that ALT_DOWN_MASK be used instead.
     */
    public static final int ALT_MASK = Event.ALT_MASK;

    
The AltGraph key modifier constant.

/**
     * The AltGraph key modifier constant.
     */
    public static final int ALT_GRAPH_MASK = 1 << 5;

    
The Mouse Button1 modifier constant.
It is recommended that BUTTON1_DOWN_MASK be used instead.

/**
     * The Mouse Button1 modifier constant.
     * It is recommended that BUTTON1_DOWN_MASK be used instead.
     */
    public static final int BUTTON1_MASK = 1 << 4;

    
The Mouse Button2 modifier constant.
It is recommended that BUTTON2_DOWN_MASK be used instead.
Note that BUTTON2_MASK has the same value as ALT_MASK.

/**
     * The Mouse Button2 modifier constant.
     * It is recommended that BUTTON2_DOWN_MASK be used instead.
     * Note that BUTTON2_MASK has the same value as ALT_MASK.
     */
    public static final int BUTTON2_MASK = Event.ALT_MASK;

    
The Mouse Button3 modifier constant.
It is recommended that BUTTON3_DOWN_MASK be used instead.
Note that BUTTON3_MASK has the same value as META_MASK.

/**
     * The Mouse Button3 modifier constant.
     * It is recommended that BUTTON3_DOWN_MASK be used instead.
     * Note that BUTTON3_MASK has the same value as META_MASK.
     */
    public static final int BUTTON3_MASK = Event.META_MASK;

    
The Shift key extended modifier constant.

Since:1.4
/**
     * The Shift key extended modifier constant.
     * @since 1.4
     */
    public static final int SHIFT_DOWN_MASK = 1 << 6;

    
The Control key extended modifier constant.

Since:1.4
/**
     * The Control key extended modifier constant.
     * @since 1.4
     */
    public static final int CTRL_DOWN_MASK = 1 << 7;

    
The Meta key extended modifier constant.

Since:1.4
/**
     * The Meta key extended modifier constant.
     * @since 1.4
     */
    public static final int META_DOWN_MASK = 1 << 8;

    
The Alt key extended modifier constant.

Since:1.4
/**
     * The Alt key extended modifier constant.
     * @since 1.4
     */
    public static final int ALT_DOWN_MASK = 1 << 9;

    
The Mouse Button1 extended modifier constant.

Since:1.4
/**
     * The Mouse Button1 extended modifier constant.
     * @since 1.4
     */
    public static final int BUTTON1_DOWN_MASK = 1 << 10;

    
The Mouse Button2 extended modifier constant.

Since:1.4
/**
     * The Mouse Button2 extended modifier constant.
     * @since 1.4
     */
    public static final int BUTTON2_DOWN_MASK = 1 << 11;

    
The Mouse Button3 extended modifier constant.

Since:1.4
/**
     * The Mouse Button3 extended modifier constant.
     * @since 1.4
     */
    public static final int BUTTON3_DOWN_MASK = 1 << 12;

    
The AltGraph key extended modifier constant.

Since:1.4
/**
     * The AltGraph key extended modifier constant.
     * @since 1.4
     */
    public static final int ALT_GRAPH_DOWN_MASK = 1 << 13;

    // the constant below MUST be updated if any extra modifier
    // bits are to be added!
    // in fact, it is undesirable to add modifier bits
    // to the same field as this may break applications
    // see bug# 5066958

    static final int FIRST_HIGH_BIT = 1 << 14;

    static final int JDK_1_3_MODIFIERS = SHIFT_DOWN_MASK - 1;
    static final int HIGH_MODIFIERS = ~( FIRST_HIGH_BIT - 1 );

    
The input event's Time stamp in UTC format.  The time stamp
indicates when the input event was created.

See Also:
@serial
/**
     * The input event's Time stamp in UTC format.  The time stamp
     * indicates when the input event was created.
     *
     * @serial
     * @see #getWhen()
     */
    long when;

    
The state of the modifier mask at the time the input
event was fired.

See Also:
@serial
/**
     * The state of the modifier mask at the time the input
     * event was fired.
     *
     * @serial
     * @see #getModifiers()
     * @see #getModifiersEx()
     * @see java.awt.event.KeyEvent
     * @see java.awt.event.MouseEvent
     */
    int modifiers;

    /*
     * A flag that indicates that this instance can be used to access
     * the system clipboard.
     */
    private transient boolean canAccessSystemClipboard;

    static {
        /* ensure that the necessary native libraries are loaded */
        NativeLibLoader.loadLibraries();
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }
    }

    
Initialize JNI field and method IDs for fields that may be
accessed from C.

/**
     * Initialize JNI field and method IDs for fields that may be
       accessed from C.
     */
    private static native void initIDs();

    
Constructs an InputEvent object with the specified source component,
modifiers, and type.

Note that passing in an invalid id results in
unspecified behavior. This method throws an
IllegalArgumentException if source
is null.

Params:
  • source – the object where the event originated
  • id – the event type
  • when – the time the event occurred
  • modifiers – represents the modifier keys and mouse buttons down
                 while the event occurred
Throws:
/**
     * Constructs an InputEvent object with the specified source component,
     * modifiers, and type.
     * <p>Note that passing in an invalid <code>id</code> results in
     * unspecified behavior. This method throws an
     * <code>IllegalArgumentException</code> if <code>source</code>
     * is <code>null</code>.
     *
     * @param source the object where the event originated
     * @param id the event type
     * @param when the time the event occurred
     * @param modifiers represents the modifier keys and mouse buttons down
     *                  while the event occurred
     * @throws IllegalArgumentException if <code>source</code> is null
     */
    InputEvent(Component source, int id, long when, int modifiers) {
        super(source, id);
        this.when = when;
        this.modifiers = modifiers;
        canAccessSystemClipboard = canAccessSystemClipboard();
    }

    private boolean canAccessSystemClipboard() {
        boolean b = false;

        if (!GraphicsEnvironment.isHeadless()) {
            SecurityManager sm = System.getSecurityManager();
            if (sm != null) {
                try {
                    sm.checkSystemClipboardAccess();
                    b = true;
                } catch (SecurityException se) {
                    if (log.isLoggable(Level.FINE)) {
                        log.log(Level.FINE, "InputEvent.canAccessSystemClipboard() got SecurityException ", se);
                    }
                }
            } else {
                b = true;
            }
        }

        return b;
    }

    
Returns whether or not the Shift modifier is down on this event.

/**
     * Returns whether or not the Shift modifier is down on this event.
     */
    public boolean isShiftDown() {
        return (modifiers & SHIFT_MASK) != 0;
    }

    
Returns whether or not the Control modifier is down on this event.

/**
     * Returns whether or not the Control modifier is down on this event.
     */
    public boolean isControlDown() {
        return (modifiers & CTRL_MASK) != 0;
    }

    
Returns whether or not the Meta modifier is down on this event.

/**
     * Returns whether or not the Meta modifier is down on this event.
     */
    public boolean isMetaDown() {
        return (modifiers & META_MASK) != 0;
    }

    
Returns whether or not the Alt modifier is down on this event.

/**
     * Returns whether or not the Alt modifier is down on this event.
     */
    public boolean isAltDown() {
        return (modifiers & ALT_MASK) != 0;
    }

    
Returns whether or not the AltGraph modifier is down on this event.

/**
     * Returns whether or not the AltGraph modifier is down on this event.
     */
    public boolean isAltGraphDown() {
        return (modifiers & ALT_GRAPH_MASK) != 0;
    }

    
Returns the timestamp of when this event occurred.

/**
     * Returns the timestamp of when this event occurred.
     */
    public long getWhen() {
        return when;
    }

    
Returns the modifier mask for this event.

/**
     * Returns the modifier mask for this event.
     */
    public int getModifiers() {
        return modifiers & (JDK_1_3_MODIFIERS | HIGH_MODIFIERS);
    }

    
Returns the extended modifier mask for this event.
Extended modifiers represent the state of all modal keys,
such as ALT, CTRL, META, and the mouse buttons just after
the event occurred


For example, if the user presses button 1 followed by
button 2, and then releases them in the same order,
the following sequence of events is generated:

   MOUSE_PRESSED:  BUTTON1_DOWN_MASK
   MOUSE_PRESSED:  BUTTON1_DOWN_MASK | BUTTON2_DOWN_MASK
   MOUSE_RELEASED: BUTTON2_DOWN_MASK
   MOUSE_CLICKED:  BUTTON2_DOWN_MASK
   MOUSE_RELEASED:
   MOUSE_CLICKED:




It is not recommended to compare the return value of this method
using == because new modifiers can be added in the future.
For example, the appropriate way to check that SHIFT and BUTTON1 are
down, but CTRL is up is demonstrated by the following code:

   int onmask = SHIFT_DOWN_MASK | BUTTON1_DOWN_MASK;
   int offmask = CTRL_DOWN_MASK;
   if ((event.getModifiersEx() & (onmask | offmask)) == onmask) {
       ...
   }


The above code will work even if new modifiers are added.

Since:1.4
/**
     * Returns the extended modifier mask for this event.
     * Extended modifiers represent the state of all modal keys,
     * such as ALT, CTRL, META, and the mouse buttons just after
     * the event occurred
     * <P>
     * For example, if the user presses <b>button 1</b> followed by
     * <b>button 2</b>, and then releases them in the same order,
     * the following sequence of events is generated:
     * <PRE>
     *    <code>MOUSE_PRESSED</code>:  <code>BUTTON1_DOWN_MASK</code>
     *    <code>MOUSE_PRESSED</code>:  <code>BUTTON1_DOWN_MASK | BUTTON2_DOWN_MASK</code>
     *    <code>MOUSE_RELEASED</code>: <code>BUTTON2_DOWN_MASK</code>
     *    <code>MOUSE_CLICKED</code>:  <code>BUTTON2_DOWN_MASK</code>
     *    <code>MOUSE_RELEASED</code>:
     *    <code>MOUSE_CLICKED</code>:
     * </PRE>
     * <P>
     * It is not recommended to compare the return value of this method
     * using <code>==</code> because new modifiers can be added in the future.
     * For example, the appropriate way to check that SHIFT and BUTTON1 are
     * down, but CTRL is up is demonstrated by the following code:
     * <PRE>
     *    int onmask = SHIFT_DOWN_MASK | BUTTON1_DOWN_MASK;
     *    int offmask = CTRL_DOWN_MASK;
     *    if ((event.getModifiersEx() & (onmask | offmask)) == onmask) {
     *        ...
     *    }
     * </PRE>
     * The above code will work even if new modifiers are added.
     *
     * @since 1.4
     */
    public int getModifiersEx() {
        return modifiers & ~JDK_1_3_MODIFIERS;
    }

    
Consumes this event so that it will not be processed
in the default manner by the source which originated it.

/**
     * Consumes this event so that it will not be processed
     * in the default manner by the source which originated it.
     */
    public void consume() {
        consumed = true;
    }

    
Returns whether or not this event has been consumed.

See Also:
  • consume
/**
     * Returns whether or not this event has been consumed.
     * @see #consume
     */
    public boolean isConsumed() {
        return consumed;
    }

    // state serialization compatibility with JDK 1.1
    static final long serialVersionUID = -2482525981698309786L;

    
Returns a String describing the extended modifier keys and
mouse buttons, such as "Shift", "Button1", or "Ctrl+Shift".
These strings can be localized by changing the
awt.properties file.

Params:
  • modifiers – a modifier mask describing the extended
               modifier keys and mouse buttons for the event
Returns:a text description of the combination of extended
        modifier keys and mouse buttons that were held down
        during the event.
Since:1.4
/**
     * Returns a String describing the extended modifier keys and
     * mouse buttons, such as "Shift", "Button1", or "Ctrl+Shift".
     * These strings can be localized by changing the
     * awt.properties file.
     *
     * @param modifiers a modifier mask describing the extended
       *                modifier keys and mouse buttons for the event
     * @return a text description of the combination of extended
     *         modifier keys and mouse buttons that were held down
     *         during the event.
     * @since 1.4
     */
    public static String getModifiersExText(int modifiers) {
        StringBuilder buf = new StringBuilder();
        if ((modifiers & InputEvent.META_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.meta", "Meta"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.CTRL_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.control", "Ctrl"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.ALT_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.alt", "Alt"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.SHIFT_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.shift", "Shift"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.ALT_GRAPH_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.altGraph", "Alt Graph"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON1_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button1", "Button1"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON2_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button2", "Button2"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON3_DOWN_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button3", "Button3"));
            buf.append("+");
        }
        if (buf.length() > 0) {
            buf.setLength(buf.length()-1); // remove trailing '+'
        }
        return buf.toString();
    }
}