https://openjdk.java.net/ 
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 * Copyright (c) 1996, 2016, 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).
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 * 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,
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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.Arrays;

import sun.awt.AWTAccessor;
import sun.awt.AWTPermissions;
import sun.util.logging.PlatformLogger;


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 PlatformLogger logger = PlatformLogger.getLogger("java.awt.event.InputEvent");

    
The Shift key modifier constant.

Deprecated:It is recommended that SHIFT_DOWN_MASK and getModifiersEx() be used instead
/**
     * The Shift key modifier constant.
     *
     * @deprecated It is recommended that SHIFT_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int SHIFT_MASK = Event.SHIFT_MASK;

    
The Control key modifier constant.

Deprecated:It is recommended that CTRL_DOWN_MASK and getModifiersEx() be used instead
/**
     * The Control key modifier constant.
     *
     * @deprecated It is recommended that CTRL_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int CTRL_MASK = Event.CTRL_MASK;

    
The Meta key modifier constant.

Deprecated:It is recommended that META_DOWN_MASK and getModifiersEx() be used instead
/**
     * The Meta key modifier constant.
     *
     * @deprecated It is recommended that META_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int META_MASK = Event.META_MASK;

    
The Alt key modifier constant.

Deprecated:It is recommended that ALT_DOWN_MASK and getModifiersEx() be used instead
/**
     * The Alt key modifier constant.
     *
     * @deprecated It is recommended that ALT_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int ALT_MASK = Event.ALT_MASK;

    
The AltGraph key modifier constant.

Deprecated:It is recommended that ALT_GRAPH_DOWN_MASK and getModifiersEx() be used instead
/**
     * The AltGraph key modifier constant.
     *
     * @deprecated It is recommended that ALT_GRAPH_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int ALT_GRAPH_MASK = 1 << 5;

    
The Mouse Button1 modifier constant.

Deprecated:It is recommended that BUTTON1_DOWN_MASK and getModifiersEx() be used instead
/**
     * The Mouse Button1 modifier constant.
     *
     * @deprecated It is recommended that BUTTON1_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public static final int BUTTON1_MASK = 1 << 4;

    
The Mouse Button2 modifier constant.

Deprecated:It is recommended that BUTTON2_DOWN_MASK and getModifiersEx() be used instead. Note that BUTTON2_MASK has the same value as ALT_MASK.
/**
     * The Mouse Button2 modifier constant.
     *
     * @deprecated It is recommended that BUTTON2_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead. Note that
     *             BUTTON2_MASK has the same value as ALT_MASK.
     */
    @Deprecated(since = "9")
    public static final int BUTTON2_MASK = Event.ALT_MASK;

    
The Mouse Button3 modifier constant.

Deprecated:It is recommended that BUTTON3_DOWN_MASK and getModifiersEx() be used instead. Note that BUTTON3_MASK has the same value as META_MASK.
/**
     * The Mouse Button3 modifier constant.
     *
     * @deprecated It is recommended that BUTTON3_DOWN_MASK and
     *             {@link #getModifiersEx()} be used instead. Note that
     *             BUTTON3_MASK has the same value as META_MASK.
     */
    @Deprecated(since = "9")
    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;

    
An array of extended modifiers for additional buttons.

See Also:
  • 
There are twenty buttons fit into 4byte space.
one more bit is reserved for FIRST_HIGH_BIT.
Since:1.7
/**
     * An array of extended modifiers for additional buttons.
     * @see #getButtonDownMasks()
     * There are twenty buttons fit into 4byte space.
     * one more bit is reserved for FIRST_HIGH_BIT.
     * @since 1.7
     */
    private static final int [] BUTTON_DOWN_MASK = new int [] { BUTTON1_DOWN_MASK,
                                                               BUTTON2_DOWN_MASK,
                                                               BUTTON3_DOWN_MASK,
                                                               1<<14, //4th physical button (this is not a wheel!)
                                                               1<<15, //(this is not a wheel!)
                                                               1<<16,
                                                               1<<17,
                                                               1<<18,
                                                               1<<19,
                                                               1<<20,
                                                               1<<21,
                                                               1<<22,
                                                               1<<23,
                                                               1<<24,
                                                               1<<25,
                                                               1<<26,
                                                               1<<27,
                                                               1<<28,
                                                               1<<29,
                                                               1<<30};

    
A method to access an array of extended modifiers for additional buttons.

Since:1.7
/**
     * A method to access an array of extended modifiers for additional buttons.
     * @since 1.7
     */
    private static int [] getButtonDownMasks(){
        return Arrays.copyOf(BUTTON_DOWN_MASK, BUTTON_DOWN_MASK.length);
    }


    
A method to obtain a mask for any existing mouse button.
The returned mask may be used for different purposes. Following are some of them:


Params:
  • button – is a number to represent a button starting from 1.
For example,

    int button = InputEvent.getMaskForButton(1);

    
will have the same meaning as

    int button = InputEvent.getMaskForButton(MouseEvent.BUTTON1);

     because MouseEvent.BUTTON1 equals to 1. If a mouse has three enabled buttons(see MouseInfo.getNumberOfButtons()) then the values from the left column passed into the method will return corresponding values from the right column: 
       button    returned mask BUTTON1 BUTTON1_DOWN_MASK BUTTON2 BUTTON2_DOWN_MASK BUTTON3 BUTTON3_DOWN_MASK 
    
If a mouse has more than three enabled buttons then more values
are admissible (4, 5, etc.). There is no assigned constants for these extended buttons.
The button masks for the extra buttons returned by this method have no assigned names like the
first three button masks.

     This method has the following implementation restriction. It returns masks for a limited number of buttons only. The maximum number is implementation dependent and may vary. This limit is defined by the relevant number of buttons that may hypothetically exist on the mouse but it is greater than the MouseInfo.getNumberOfButtons().
Throws:
  • IllegalArgumentException – if button is less than zero or greater than the number of button masks reserved for buttons
See Also:
Returns:a mask for an existing mouse button.
Since:1.7
/**
     * A method to obtain a mask for any existing mouse button.
     * The returned mask may be used for different purposes. Following are some of them:
     * <ul>
     * <li> {@link java.awt.Robot#mousePress(int) mousePress(buttons)} and
     *      {@link java.awt.Robot#mouseRelease(int) mouseRelease(buttons)}
     * <li> as a {@code modifiers} parameter when creating a new {@link MouseEvent} instance
     * <li> to check {@link MouseEvent#getModifiersEx() modifiersEx} of existing {@code MouseEvent}
     * </ul>
     * @param button is a number to represent a button starting from 1.
     * For example,
     * <pre>
     * int button = InputEvent.getMaskForButton(1);
     * </pre>
     * will have the same meaning as
     * <pre>
     * int button = InputEvent.getMaskForButton(MouseEvent.BUTTON1);
     * </pre>
     * because {@link MouseEvent#BUTTON1 MouseEvent.BUTTON1} equals to 1.
     * If a mouse has three enabled buttons(see {@link java.awt.MouseInfo#getNumberOfButtons() MouseInfo.getNumberOfButtons()})
     * then the values from the left column passed into the method will return
     * corresponding values from the right column:
     * <PRE>
     *    <b>button </b>   <b>returned mask</b>
     *    {@link MouseEvent#BUTTON1 BUTTON1}  {@link MouseEvent#BUTTON1_DOWN_MASK BUTTON1_DOWN_MASK}
     *    {@link MouseEvent#BUTTON2 BUTTON2}  {@link MouseEvent#BUTTON2_DOWN_MASK BUTTON2_DOWN_MASK}
     *    {@link MouseEvent#BUTTON3 BUTTON3}  {@link MouseEvent#BUTTON3_DOWN_MASK BUTTON3_DOWN_MASK}
     * </PRE>
     * If a mouse has more than three enabled buttons then more values
     * are admissible (4, 5, etc.). There is no assigned constants for these extended buttons.
     * The button masks for the extra buttons returned by this method have no assigned names like the
     * first three button masks.
     * <p>
     * This method has the following implementation restriction.
     * It returns masks for a limited number of buttons only. The maximum number is
     * implementation dependent and may vary.
     * This limit is defined by the relevant number
     * of buttons that may hypothetically exist on the mouse but it is greater than the
     * {@link java.awt.MouseInfo#getNumberOfButtons() MouseInfo.getNumberOfButtons()}.
     *
     * @return a mask for an existing mouse button.
     * @throws IllegalArgumentException if {@code button} is less than zero or greater than the number
     *         of button masks reserved for buttons
     * @since 1.7
     * @see java.awt.MouseInfo#getNumberOfButtons()
     * @see Toolkit#areExtraMouseButtonsEnabled()
     * @see MouseEvent#getModifiers()
     * @see MouseEvent#getModifiersEx()
     */
    public static int getMaskForButton(int button) {
        if (button <= 0 || button > BUTTON_DOWN_MASK.length) {
            throw new IllegalArgumentException("button doesn't exist " + button);
        }
        return BUTTON_DOWN_MASK[button - 1];
    }

    // 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 << 31;

    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();
        }
        AWTAccessor.setInputEventAccessor(
            new AWTAccessor.InputEventAccessor() {
                public int[] getButtonDownMasks() {
                    return InputEvent.getButtonDownMasks();
                }

                public boolean canAccessSystemClipboard(InputEvent event) {
                    return event.canAccessSystemClipboard;
                }

                @Override
                public void setCanAccessSystemClipboard(InputEvent event,
                        boolean canAccessSystemClipboard) {
                    event.canAccessSystemClipboard = canAccessSystemClipboard;
                }
            });
    }

    
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.

 This method throws an IllegalArgumentException if source is null. 
Params:
  • source – the object where the event originated
  • id –  the integer that identifies the event type. It is allowed to pass as parameter any value that allowed for some subclass of InputEvent class. Passing in the value different from those values result in unspecified behavior
  • when –         a long int that gives the time the event occurred.
                    Passing negative or zero value
                    is not recommended
  • modifiers –  a modifier mask describing the modifier keys and mouse buttons (for example, shift, ctrl, alt, and meta) that are down during the event. Only extended modifiers are allowed to be used as a value for this parameter (see the getModifiersEx class for the description of extended modifiers). Passing negative parameter is not recommended. Zero value means that no modifiers were passed
Throws:
See Also:
/**
     * Constructs an InputEvent object with the specified source component,
     * modifiers, and type.
     * <p> This method throws an
     * {@code IllegalArgumentException} if {@code source}
     * is {@code null}.
     *
     * @param source the object where the event originated
     * @param id           the integer that identifies the event type.
     *                     It is allowed to pass as parameter any value that
     *                     allowed for some subclass of {@code InputEvent} class.
     *                     Passing in the value different from those values result
     *                     in unspecified behavior
     * @param when         a long int that gives the time the event occurred.
     *                     Passing negative or zero value
     *                     is not recommended
     * @param modifiers    a modifier mask describing the modifier keys and mouse
     *                     buttons (for example, shift, ctrl, alt, and meta) that
     *                     are down during the event.
     *                     Only extended modifiers are allowed to be used as a
     *                     value for this parameter (see the {@link InputEvent#getModifiersEx}
     *                     class for the description of extended modifiers).
     *                     Passing negative parameter
     *                     is not recommended.
     *                     Zero value means that no modifiers were passed
     * @throws IllegalArgumentException if {@code source} is null
     * @see #getSource()
     * @see #getID()
     * @see #getWhen()
     * @see #getModifiers()
     */
    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.checkPermission(AWTPermissions.ACCESS_CLIPBOARD_PERMISSION);
                    b = true;
                } catch (SecurityException se) {
                    if (logger.isLoggable(PlatformLogger.Level.FINE)) {
                        logger.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
/**
     * Returns whether or not the Shift modifier is down on this event.
     * @return whether or not the Shift modifier is down on this event
     */
    public boolean isShiftDown() {
        return (modifiers & SHIFT_DOWN_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
/**
     * Returns whether or not the Control modifier is down on this event.
     * @return whether or not the Control modifier is down on this event
     */
    public boolean isControlDown() {
        return (modifiers & CTRL_DOWN_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
/**
     * Returns whether or not the Meta modifier is down on this event.
     * @return whether or not the Meta modifier is down on this event
     */
    public boolean isMetaDown() {
        return (modifiers & META_DOWN_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
/**
     * Returns whether or not the Alt modifier is down on this event.
     * @return whether or not the Alt modifier is down on this event
     */
    public boolean isAltDown() {
        return (modifiers & ALT_DOWN_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
/**
     * Returns whether or not the AltGraph modifier is down on this event.
     * @return whether or not the AltGraph modifier is down on this event
     */
    public boolean isAltGraphDown() {
        return (modifiers & ALT_GRAPH_DOWN_MASK) != 0;
    }

    
Returns the difference in milliseconds between the timestamp of when this event occurred and
midnight, January 1, 1970 UTC.

Returns:the difference in milliseconds between the timestamp and midnight, January 1, 1970 UTC
/**
     * Returns the difference in milliseconds between the timestamp of when this event occurred and
     * midnight, January 1, 1970 UTC.
     * @return the difference in milliseconds between the timestamp and midnight, January 1, 1970 UTC
     */
    public long getWhen() {
        return when;
    }

    
Returns the modifier mask for this event.

Returns:the modifier mask for this event
Deprecated:It is recommended that extended modifier keys and getModifiersEx() be used instead
/**
     * Returns the modifier mask for this event.
     *
     * @return the modifier mask for this event
     * @deprecated It is recommended that extended modifier keys and
     *             {@link #getModifiersEx()} be used instead
     */
    @Deprecated(since = "9")
    public int getModifiers() {
        return modifiers & (JDK_1_3_MODIFIERS | HIGH_MODIFIERS);
    }

    
Returns the extended modifier mask for this event.


Extended modifiers are the modifiers that ends with the _DOWN_MASK suffix,
such as ALT_DOWN_MASK, BUTTON1_DOWN_MASK, and others.


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.

Returns:the extended modifier mask for this event
Since:1.4
/**
     * Returns the extended modifier mask for this event.
     * <P>
     * Extended modifiers are the modifiers that ends with the _DOWN_MASK suffix,
     * such as ALT_DOWN_MASK, BUTTON1_DOWN_MASK, and others.
     * <P>
     * 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 BUTTON1_DOWN_MASK}
     *    {@code MOUSE_PRESSED}:  {@code BUTTON1_DOWN_MASK | BUTTON2_DOWN_MASK}
     *    {@code MOUSE_RELEASED}: {@code BUTTON2_DOWN_MASK}
     *    {@code MOUSE_CLICKED}:  {@code BUTTON2_DOWN_MASK}
     *    {@code MOUSE_RELEASED}:
     *    {@code MOUSE_CLICKED}:
     * </PRE>
     * <P>
     * It is not recommended to compare the return value of this method
     * using {@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() &amp; (onmask | offmask)) == onmask) {
     *        ...
     *    }
     * </PRE>
     * The above code will work even if new modifiers are added.
     *
     * @return the extended modifier mask for this event
     * @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:
Returns:whether or not this event has been consumed
/**
     * Returns whether or not this event has been consumed.
     * @return 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. 

Note that passing negative parameter is incorrect,
and will cause the returning an unspecified string.
Zero parameter means that no modifiers were passed and will
cause the returning an empty string.

Params:
  • modifiers – a modifier mask describing the extended
               modifier keys and mouse buttons for the event
Returns:a String describing the extended modifier keys and
mouse buttons
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
     * {@code awt.properties} file.
     * <p>
     * Note that passing negative parameter is incorrect,
     * and will cause the returning an unspecified string.
     * Zero parameter means that no modifiers were passed and will
     * cause the returning an empty string.
     *
     * @return a String describing the extended modifier keys and
     * mouse buttons
     *
     * @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("+");
        }

        int buttonNumber = 1;
        for (int mask : InputEvent.BUTTON_DOWN_MASK){
            if ((modifiers & mask) != 0) {
                buf.append(Toolkit.getProperty("AWT.button"+buttonNumber, "Button"+buttonNumber));
                buf.append("+");
            }
            buttonNumber++;
        }
        if (buf.length() > 0) {
            buf.setLength(buf.length()-1); // remove trailing '+'
        }
        return buf.toString();
    }
}