keyevent.java

JAVA基本类源代码,大家可以学习学习!

/*
 * @(#)KeyEvent.java	1.65 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.awt.event;

import java.awt.Event;
import java.awt.Component;
import java.awt.GraphicsEnvironment;
import java.awt.Toolkit;
import java.io.IOException;
import java.io.ObjectInputStream;

/**
 * An event which indicates that a keystroke occurred in a component.
 * <p>
 * This low-level event is generated by a component object (such as a text 
 * field) when a key is pressed, released, or typed.  
 * The event is passed to every <code>KeyListener</code>
 * or <code>KeyAdapter</code> object which registered to receive such
 * events using the component's <code>addKeyListener</code> method.
 * (<code>KeyAdapter</code> objects implement the 
 * <code>KeyListener</code> interface.)  Each such listener object 
 * gets this <code>KeyEvent</code> when the event occurs.
 *
 * <p>
 * <em>"Key typed" events</em> are higher-level and generally do not depend on 
 * the platform or keyboard layout.  They are generated when a Unicode character 
 * is entered, and are the preferred way to find out about character input.
 * In the simplest case, a key typed event is produced by a single key press 
 * (e.g., 'a').  Often, however, characters are produced by series of key 
 * presses (e.g., 'shift' + 'a'), and the mapping from key pressed events to 
 * key typed events may be many-to-one or many-to-many.  Key releases are not 
 * usually necessary to generate a key typed event, but there are some cases 
 * where the key typed event is not generated until a key is released (e.g., 
 * entering ASCII sequences via the Alt-Numpad method in Windows).  
 * No key typed events are generated for keys that don't generate Unicode 
 * characters (e.g., action keys, modifier keys, etc.).
 * The getKeyChar method always returns a valid Unicode character or 
 * CHAR_UNDEFINED.  
 * For key pressed and key released events, the getKeyCode method returns 
 * the event's keyCode.  For key typed events, the getKeyCode method 
 * always returns VK_UNDEFINED.
 *
 * <p>
 * <em>"Key pressed" and "key released" events</em> are lower-level and depend 
 * on the platform and keyboard layout. They are generated whenever a key is 
 * pressed or released, and are the only way to find out about keys that don't 
 * generate character input (e.g., action keys, modifier keys, etc.). The key 
 * being pressed or released is indicated by the getKeyCode method, which returns 
 * a virtual key code.
 *
 * <p>
 * <em>Virtual key codes</em> are used to report which keyboard key has
 * been pressed, rather than a character generated by the combination
 * of one or more keystrokes (such as "A", which comes from shift and "a").  
 *
 * <p>
 * For example, pressing the Shift key will cause a KEY_PRESSED event 
 * with a VK_SHIFT keyCode, while pressing the 'a' key will result in 
 * a VK_A keyCode.  After the 'a' key is released, a KEY_RELEASED event 
 * will be fired with VK_A. Separately, a KEY_TYPED event with a keyChar 
 * value of 'A' is generated.
 *
 * <p>
 * Notes:
 * <ul>
 * <li>Key combinations which do not result in Unicode characters, such as action 
 * keys like F1 and the HELP key, do not generate KEY_TYPED events.
 * <li>Not all keyboards or systems are capable of generating all
 * virtual key codes.  No attempt is made in Java to generate these keys 
 * artificially. 
 * <li>Virtual key codes do not identify a physical key: they depend on the
 * platform and keyboard layout. For example, the key that generates VK_Q 
 * when using a U.S. keyboard layout will generate VK_A when using a French 
 * keyboard layout.
 * <li>Not all characters have a keycode associated with them.  For example, 
 * there is no keycode for the question mark because there is no keyboard 
 * for which it appears on the primary layer.  
 * <li>In order to support the platform-independent handling of action keys,
 * the Java platform uses a few additional virtual key constants for functions
 * that would otherwise have to be recognized by interpreting virtual key codes
 * and modifiers. For example, for Japanese Windows keyboards, VK_ALL_CANDIDATES
 * is returned instead of VK_CONVERT with the ALT modifier.
 * </ul>
 *
 * <p>
 * WARNING: Aside from those keys that are defined by the Java language
 * (VK_ENTER, VK_BACK_SPACE, and VK_TAB), do not rely on the values of the VK_
 * constants.  Sun reserves the right to change these values as needed
 * to accomodate a wider range of keyboards in the future.  
 *
 * @author Carl Quinn
 * @author Amy Fowler
 * @author Norbert Lindenberg
 * @version 1.65 01/23/03
 *
 * @see KeyAdapter
 * @see KeyListener
 * @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/keylistener.html">Tutorial: Writing a Key Listener</a>
 * @see <a href="http://www.awl.com/cp/javaseries/jcl1_2.html">Reference: The Java Class Libraries (update file)</a>
 *
 * @since 1.1
 */
public class KeyEvent extends InputEvent {

    /**
     * Stores the state of native event dispatching system
     * - true, if when the event was created event proxying 
     *         mechanism was active
     * - false, if it was inactive
     * Used in Component.dispatchEventImpl to correctly dispatch
     * events when proxy is active
     */
    private boolean isProxyActive = false;

    /**
     * The first number in the range of ids used for key events.
     */
    public static final int KEY_FIRST = 400;

    /**
     * The last number in the range of ids used for key events.
     */
    public static final int KEY_LAST  = 402;

    /**
     * The "key typed" event.  This event is generated when a character is
     * entered.  In the simplest case, it is produced by a single key press.  
     * Often, however, characters are produced by series of key presses, and 
     * the mapping from key pressed events to key typed events may be 
     * many-to-one or many-to-many.  
     */
    public static final int KEY_TYPED = KEY_FIRST;

    /**
     * The "key pressed" event. This event is generated when a key
     * is pushed down.
     */
    public static final int KEY_PRESSED = 1 + KEY_FIRST; //Event.KEY_PRESS

    /**
     * The "key released" event. This event is generated when a key
     * is let up.
     */
    public static final int KEY_RELEASED = 2 + KEY_FIRST; //Event.KEY_RELEASE

    /* Virtual key codes. */

    public static final int VK_ENTER          = '\n';
    public static final int VK_BACK_SPACE     = '\b';
    public static final int VK_TAB            = '\t';
    public static final int VK_CANCEL         = 0x03;
    public static final int VK_CLEAR          = 0x0C;
    public static final int VK_SHIFT          = 0x10;
    public static final int VK_CONTROL        = 0x11;
    public static final int VK_ALT            = 0x12;
    public static final int VK_PAUSE          = 0x13;
    public static final int VK_CAPS_LOCK      = 0x14;
    public static final int VK_ESCAPE         = 0x1B;
    public static final int VK_SPACE          = 0x20;
    public static final int VK_PAGE_UP        = 0x21;
    public static final int VK_PAGE_DOWN      = 0x22;
    public static final int VK_END            = 0x23;
    public static final int VK_HOME           = 0x24;

    /**
     * Constant for the non-numpad <b>left</b> arrow key.
     * @see #VK_KP_LEFT
     */
    public static final int VK_LEFT           = 0x25;

    /**
     * Constant for the non-numpad <b>up</b> arrow key.
     * @see #VK_KP_UP
     */
    public static final int VK_UP             = 0x26;

    /**
     * Constant for the non-numpad <b>right</b> arrow key.
     * @see #VK_KP_RIGHT
     */
    public static final int VK_RIGHT          = 0x27;

    /**
     * Constant for the non-numpad <b>down</b> arrow key.
     * @see #VK_KP_DOWN
     */
    public static final int VK_DOWN           = 0x28;

    public static final int VK_COMMA          = 0x2C;

    /**
     * Constant for the "-" key.
     * @since 1.2
     */
    public static final int VK_MINUS          = 0x2D;

    public static final int VK_PERIOD         = 0x2E;
    public static final int VK_SLASH          = 0x2F;

    /** VK_0 thru VK_9 are the same as ASCII '0' thru '9' (0x30 - 0x39) */
    public static final int VK_0              = 0x30;
    public static final int VK_1              = 0x31;
    public static final int VK_2              = 0x32;
    public static final int VK_3              = 0x33;
    public static final int VK_4              = 0x34;
    public static final int VK_5              = 0x35;
    public static final int VK_6              = 0x36;
    public static final int VK_7              = 0x37;
    public static final int VK_8              = 0x38;
    public static final int VK_9              = 0x39;

    public static final int VK_SEMICOLON      = 0x3B;
    public static final int VK_EQUALS         = 0x3D;

    /** VK_A thru VK_Z are the same as ASCII 'A' thru 'Z' (0x41 - 0x5A) */
    public static final int VK_A              = 0x41;
    public static final int VK_B              = 0x42;
    public static final int VK_C              = 0x43;
    public static final int VK_D              = 0x44;
    public static final int VK_E              = 0x45;
    public static final int VK_F              = 0x46;
    public static final int VK_G              = 0x47;
    public static final int VK_H              = 0x48;
    public static final int VK_I              = 0x49;
    public static final int VK_J              = 0x4A;
    public static final int VK_K              = 0x4B;
    public static final int VK_L              = 0x4C;
    public static final int VK_M              = 0x4D;
    public static final int VK_N              = 0x4E;
    public static final int VK_O              = 0x4F;
    public static final int VK_P              = 0x50;
    public static final int VK_Q              = 0x51;
    public static final int VK_R              = 0x52;
    public static final int VK_S              = 0x53;
    public static final int VK_T              = 0x54;
    public static final int VK_U              = 0x55;
    public static final int VK_V              = 0x56;
    public static final int VK_W              = 0x57;
    public static final int VK_X              = 0x58;
    public static final int VK_Y              = 0x59;
    public static final int VK_Z              = 0x5A;

    public static final int VK_OPEN_BRACKET   = 0x5B;
    public static final int VK_BACK_SLASH     = 0x5C;
    public static final int VK_CLOSE_BRACKET  = 0x5D;

    public static final int VK_NUMPAD0        = 0x60;
    public static final int VK_NUMPAD1        = 0x61;
    public static final int VK_NUMPAD2        = 0x62;
    public static final int VK_NUMPAD3        = 0x63;
    public static final int VK_NUMPAD4        = 0x64;
    public static final int VK_NUMPAD5        = 0x65;
    public static final int VK_NUMPAD6        = 0x66;
    public static final int VK_NUMPAD7        = 0x67;
    public static final int VK_NUMPAD8        = 0x68;
    public static final int VK_NUMPAD9        = 0x69;
    public static final int VK_MULTIPLY       = 0x6A;
    public static final int VK_ADD            = 0x6B;

    /** 
     * This constant is obsolete, and is included only for backwards
     * compatibility.
     * @see #VK_SEPARATOR
     */
    public static final int VK_SEPARATER      = 0x6C;

    /** 
     * Constant for the Numpad Separator key. 
     * @since 1.4
     */
    public static final int VK_SEPARATOR      = VK_SEPARATER;

    public static final int VK_SUBTRACT       = 0x6D;
    public static final int VK_DECIMAL        = 0x6E;
    public static final int VK_DIVIDE         = 0x6F;
    public static final int VK_DELETE         = 0x7F; /* ASCII DEL */
    public static final int VK_NUM_LOCK       = 0x90;
    public static final int VK_SCROLL_LOCK    = 0x91;

    /** Constant for the F1 function key. */
    public static final int VK_F1             = 0x70;

    /** Constant for the F2 function key. */
    public static final int VK_F2             = 0x71;

    /** Constant for the F3 function key. */
    public static final int VK_F3             = 0x72;

    /** Constant for the F4 function key. */
    public static final int VK_F4             = 0x73;

    /** Constant for the F5 function key. */
    public static final int VK_F5             = 0x74;

    /** Constant for the F6 function key. */
    public static final int VK_F6             = 0x75;

    /** Constant for the F7 function key. */
    public static final int VK_F7             = 0x76;

    /** Constant for the F8 function key. */
    public static final int VK_F8             = 0x77;

    /** Constant for the F9 function key. */
    public static final int VK_F9             = 0x78;

    /** Constant for the F10 function key. */
    public static final int VK_F10            = 0x79;

    /** Constant for the F11 function key. */
    public static final int VK_F11            = 0x7A;

    /** Constant for the F12 function key. */
    public static final int VK_F12            = 0x7B;

    /**
     * Constant for the F13 function key.
     * @since 1.2
     */
    /* F13 - F24 are used on IBM 3270 keyboard; use random range for constants. */
    public static final int VK_F13            = 0xF000;
 
    /**
     * Constant for the F14 function key.
     * @since 1.2
     */
    public static final int VK_F14            = 0xF001;
 
    /**
     * Constant for the F15 function key.
     * @since 1.2
     */
    public static final int VK_F15            = 0xF002;
 
    /**
     * Constant for the F16 function key.
     * @since 1.2
     */
    public static final int VK_F16            = 0xF003;
 
    /**
     * Constant for the F17 function key.
     * @since 1.2
     */
    public static final int VK_F17            = 0xF004;
 
    /**
     * Constant for the F18 function key.
     * @since 1.2
     */
    public static final int VK_F18            = 0xF005;
 
    /**
     * Constant for the F19 function key.
     * @since 1.2
     */
    public static final int VK_F19            = 0xF006;
 
    /**
     * Constant for the F20 function key.
     * @since 1.2
     */
    public static final int VK_F20            = 0xF007;
 
    /**