core/java/android/view/KeyEvent.java

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.view;

import android.os.Parcel;
import android.os.Parcelable;
import android.text.method.MetaKeyKeyListener;
import android.util.Log;
import android.util.Slog;
import android.util.SparseIntArray;
import android.view.KeyCharacterMap;
import android.view.KeyCharacterMap.KeyData;

/**
 * Object used to report key and button events.
 * <p>
 * Each key press is described by a sequence of key events.  A key press
 * starts with a key event with {@link #ACTION_DOWN}.  If the key is held
 * sufficiently long that it repeats, then the initial down is followed
 * additional key events with {@link #ACTION_DOWN} and a non-zero value for
 * {@link #getRepeatCount()}.  The last key event is a {@link #ACTION_UP}
 * for the key up.  If the key press is canceled, the key up event will have the
 * {@link #FLAG_CANCELED} flag set.
 * </p><p>
 * Key events are generally accompanied by a key code ({@link #getKeyCode()}),
 * scan code ({@link #getScanCode()}) and meta state ({@link #getMetaState()}).
 * Key code constants are defined in this class.  Scan code constants are raw
 * device-specific codes obtained from the OS and so are not generally meaningful
 * to applications unless interpreted using the {@link KeyCharacterMap}.
 * Meta states describe the pressed state of key modifiers
 * such as {@link #META_SHIFT_ON} or {@link #META_ALT_ON}.
 * </p><p>
 * Key codes typically correspond one-to-one with individual keys on an input device.
 * Many keys and key combinations serve quite different functions on different
 * input devices so care must be taken when interpreting them.  Always use the
 * {@link KeyCharacterMap} associated with the input device when mapping keys
 * to characters.  Be aware that there may be multiple key input devices active
 * at the same time and each will have its own key character map.
 * </p><p>
 * When interacting with an IME, the framework may deliver key events
 * with the special action {@link #ACTION_MULTIPLE} that either specifies
 * that single repeated key code or a sequence of characters to insert.
 * </p><p>
 * In general, the framework cannot guarantee that the key events it delivers
 * to a view always constitute complete key sequences since some events may be dropped
 * or modified by containing views before they are delivered.  The view implementation
 * should be prepared to handle {@link #FLAG_CANCELED} and should tolerate anomalous
 * situations such as receiving a new {@link #ACTION_DOWN} without first having
 * received an {@link #ACTION_UP} for the prior key press.
 * </p><p>
 * Refer to {@link InputDevice} for more information about how different kinds of
 * input devices and sources represent keys and buttons.
 * </p>
 */
public class KeyEvent extends InputEvent implements Parcelable {
    /** Key code constant: Unknown key code. */
    public static final int KEYCODE_UNKNOWN         = 0;
    /** Key code constant: Soft Left key.
     * Usually situated below the display on phones and used as a multi-function
     * feature key for selecting a software defined function shown on the bottom left
     * of the display. */
    public static final int KEYCODE_SOFT_LEFT       = 1;
    /** Key code constant: Soft Right key.
     * Usually situated below the display on phones and used as a multi-function
     * feature key for selecting a software defined function shown on the bottom right
     * of the display. */
    public static final int KEYCODE_SOFT_RIGHT      = 2;
    /** Key code constant: Home key.
     * This key is handled by the framework and is never delivered to applications. */
    public static final int KEYCODE_HOME            = 3;
    /** Key code constant: Back key. */
    public static final int KEYCODE_BACK            = 4;
    /** Key code constant: Call key. */
    public static final int KEYCODE_CALL            = 5;
    /** Key code constant: End Call key. */
    public static final int KEYCODE_ENDCALL         = 6;
    /** Key code constant: '0' key. */
    public static final int KEYCODE_0               = 7;
    /** Key code constant: '1' key. */
    public static final int KEYCODE_1               = 8;
    /** Key code constant: '2' key. */
    public static final int KEYCODE_2               = 9;
    /** Key code constant: '3' key. */
    public static final int KEYCODE_3               = 10;
    /** Key code constant: '4' key. */
    public static final int KEYCODE_4               = 11;
    /** Key code constant: '5' key. */
    public static final int KEYCODE_5               = 12;
    /** Key code constant: '6' key. */
    public static final int KEYCODE_6               = 13;
    /** Key code constant: '7' key. */
    public static final int KEYCODE_7               = 14;
    /** Key code constant: '8' key. */
    public static final int KEYCODE_8               = 15;
    /** Key code constant: '9' key. */
    public static final int KEYCODE_9               = 16;
    /** Key code constant: '*' key. */
    public static final int KEYCODE_STAR            = 17;
    /** Key code constant: '#' key. */
    public static final int KEYCODE_POUND           = 18;
    /** Key code constant: Directional Pad Up key.
     * May also be synthesized from trackball motions. */
    public static final int KEYCODE_DPAD_UP         = 19;
    /** Key code constant: Directional Pad Down key.
     * May also be synthesized from trackball motions. */
    public static final int KEYCODE_DPAD_DOWN       = 20;
    /** Key code constant: Directional Pad Left key.
     * May also be synthesized from trackball motions. */
    public static final int KEYCODE_DPAD_LEFT       = 21;
    /** Key code constant: Directional Pad Right key.
     * May also be synthesized from trackball motions. */
    public static final int KEYCODE_DPAD_RIGHT      = 22;
    /** Key code constant: Directional Pad Center key.
     * May also be synthesized from trackball motions. */
    public static final int KEYCODE_DPAD_CENTER     = 23;
    /** Key code constant: Volume Up key.
     * Adjusts the speaker volume up. */
    public static final int KEYCODE_VOLUME_UP       = 24;
    /** Key code constant: Volume Down key.
     * Adjusts the speaker volume down. */
    public static final int KEYCODE_VOLUME_DOWN     = 25;
    /** Key code constant: Power key. */
    public static final int KEYCODE_POWER           = 26;
    /** Key code constant: Camera key.
     * Used to launch a camera application or take pictures. */
    public static final int KEYCODE_CAMERA          = 27;
    /** Key code constant: Clear key. */
    public static final int KEYCODE_CLEAR           = 28;
    /** Key code constant: 'A' key. */
    public static final int KEYCODE_A               = 29;
    /** Key code constant: 'B' key. */
    public static final int KEYCODE_B               = 30;
    /** Key code constant: 'C' key. */
    public static final int KEYCODE_C               = 31;
    /** Key code constant: 'D' key. */
    public static final int KEYCODE_D               = 32;
    /** Key code constant: 'E' key. */
    public static final int KEYCODE_E               = 33;
    /** Key code constant: 'F' key. */
    public static final int KEYCODE_F               = 34;
    /** Key code constant: 'G' key. */
    public static final int KEYCODE_G               = 35;
    /** Key code constant: 'H' key. */
    public static final int KEYCODE_H               = 36;
    /** Key code constant: 'I' key. */
    public static final int KEYCODE_I               = 37;
    /** Key code constant: 'J' key. */
    public static final int KEYCODE_J               = 38;
    /** Key code constant: 'K' key. */
    public static final int KEYCODE_K               = 39;
    /** Key code constant: 'L' key. */
    public static final int KEYCODE_L               = 40;
    /** Key code constant: 'M' key. */
    public static final int KEYCODE_M               = 41;
    /** Key code constant: 'N' key. */
    public static final int KEYCODE_N               = 42;
    /** Key code constant: 'O' key. */
    public static final int KEYCODE_O               = 43;
    /** Key code constant: 'P' key. */
    public static final int KEYCODE_P               = 44;
    /** Key code constant: 'Q' key. */
    public static final int KEYCODE_Q               = 45;
    /** Key code constant: 'R' key. */
    public static final int KEYCODE_R               = 46;
    /** Key code constant: 'S' key. */
    public static final int KEYCODE_S               = 47;
    /** Key code constant: 'T' key. */
    public static final int KEYCODE_T               = 48;
    /** Key code constant: 'U' key. */
    public static final int KEYCODE_U               = 49;
    /** Key code constant: 'V' key. */
    public static final int KEYCODE_V               = 50;
    /** Key code constant: 'W' key. */
    public static final int KEYCODE_W               = 51;
    /** Key code constant: 'X' key. */
    public static final int KEYCODE_X               = 52;
    /** Key code constant: 'Y' key. */
    public static final int KEYCODE_Y               = 53;
    /** Key code constant: 'Z' key. */
    public static final int KEYCODE_Z               = 54;
    /** Key code constant: ',' key. */
    public static final int KEYCODE_COMMA           = 55;
    /** Key code constant: '.' key. */
    public static final int KEYCODE_PERIOD          = 56;
    /** Key code constant: Left Alt modifier key. */
    public static final int KEYCODE_ALT_LEFT        = 57;
    /** Key code constant: Right Alt modifier key. */
    public static final int KEYCODE_ALT_RIGHT       = 58;
    /** Key code constant: Left Shift modifier key. */
    public static final int KEYCODE_SHIFT_LEFT      = 59;
    /** Key code constant: Right Shift modifier key. */
    public static final int KEYCODE_SHIFT_RIGHT     = 60;
    /** Key code constant: Tab key. */
    public static final int KEYCODE_TAB             = 61;
    /** Key code constant: Space key. */
    public static final int KEYCODE_SPACE           = 62;
    /** Key code constant: Symbol modifier key.
     * Used to enter alternate symbols. */
    public static final int KEYCODE_SYM             = 63;
    /** Key code constant: Explorer special function key.
     * Used to launch a browser application. */
    public static final int KEYCODE_EXPLORER        = 64;
    /** Key code constant: Envelope special function key.
     * Used to launch a mail application. */
    public static final int KEYCODE_ENVELOPE        = 65;
    /** Key code constant: Enter key. */
    public static final int KEYCODE_ENTER           = 66;
    /** Key code constant: Backspace key.
     * Deletes characters before the insertion point, unlike {@link #KEYCODE_FORWARD_DEL}. */
    public static final int KEYCODE_DEL             = 67;
    /** Key code constant: '`' (backtick) key. */
    public static final int KEYCODE_GRAVE           = 68;
    /** Key code constant: '-'. */
    public static final int KEYCODE_MINUS           = 69;
    /** Key code constant: '=' key. */
    public static final int KEYCODE_EQUALS          = 70;
    /** Key code constant: '[' key. */
    public static final int KEYCODE_LEFT_BRACKET    = 71;
    /** Key code constant: ']' key. */
    public static final int KEYCODE_RIGHT_BRACKET   = 72;
    /** Key code constant: '\' key. */
    public static final int KEYCODE_BACKSLASH       = 73;
    /** Key code constant: ';' key. */
    public static final int KEYCODE_SEMICOLON       = 74;
    /** Key code constant: ''' (apostrophe) key. */
    public static final int KEYCODE_APOSTROPHE      = 75;
    /** Key code constant: '/' key. */
    public static final int KEYCODE_SLASH           = 76;
    /** Key code constant: '@' key. */
    public static final int KEYCODE_AT              = 77;
    /** Key code constant: Number modifier key.
     * Used to enter numeric symbols.
     * This key is not Num Lock; it is more like {@link #KEYCODE_ALT_LEFT} and is
     * interpreted as an ALT key by {@link android.text.method.MetaKeyKeyListener}. */
    public static final int KEYCODE_NUM             = 78;
    /** Key code constant: Headset Hook key.
     * Used to hang up calls and stop media. */
    public static final int KEYCODE_HEADSETHOOK     = 79;
    /** Key code constant: Camera Focus key.
     * Used to focus the camera. */
    public static final int KEYCODE_FOCUS           = 80;   // *Camera* focus
    /** Key code constant: '+' key. */
    public static final int KEYCODE_PLUS            = 81;
    /** Key code constant: Menu key. */
    public static final int KEYCODE_MENU            = 82;
    /** Key code constant: Notification key. */
    public static final int KEYCODE_NOTIFICATION    = 83;
    /** Key code constant: Search key. */
    public static final int KEYCODE_SEARCH          = 84;
    /** Key code constant: Play/Pause media key. */
    public static final int KEYCODE_MEDIA_PLAY_PAUSE= 85;
    /** Key code constant: Stop media key. */
    public static final int KEYCODE_MEDIA_STOP      = 86;
    /** Key code constant: Play Next media key. */
    public static final int KEYCODE_MEDIA_NEXT      = 87;
    /** Key code constant: Play Previous media key. */
    public static final int KEYCODE_MEDIA_PREVIOUS  = 88;
    /** Key code constant: Rewind media key. */
    public static final int KEYCODE_MEDIA_REWIND    = 89;
    /** Key code constant: Fast Forward media key. */
    public static final int KEYCODE_MEDIA_FAST_FORWARD = 90;
    /** Key code constant: Mute key.
     * Mutes the microphone, unlike {@link #KEYCODE_VOLUME_MUTE}. */
    public static final int KEYCODE_MUTE            = 91;
    /** Key code constant: Page Up key. */
    public static final int KEYCODE_PAGE_UP         = 92;
    /** Key code constant: Page Down key. */
    public static final int KEYCODE_PAGE_DOWN       = 93;
    /** Key code constant: Picture Symbols modifier key.
     * Used to switch symbol sets (Emoji, Kao-moji). */
    public static final int KEYCODE_PICTSYMBOLS     = 94;   // switch symbol-sets (Emoji,Kao-moji)
    /** Key code constant: Switch Charset modifier key.
     * Used to switch character sets (Kanji, Katakana). */
    public static final int KEYCODE_SWITCH_CHARSET  = 95;   // switch char-sets (Kanji,Katakana)
    /** Key code constant: A Button key.
     * On a game controller, the A button should be either the button labeled A
     * or the first button on the upper row of controller buttons. */
    public static final int KEYCODE_BUTTON_A        = 96;
    /** Key code constant: B Button key.
     * On a game controller, the B button should be either the button labeled B
     * or the second button on the upper row of controller buttons. */
    public static final int KEYCODE_BUTTON_B        = 97;
    /** Key code constant: C Button key.
     * On a game controller, the C button should be either the button labeled C
     * or the third button on the upper row of controller buttons. */
    public static final int KEYCODE_BUTTON_C        = 98;
    /** Key code constant: X Button key.
     * On a game controller, the X button should be either the button labeled X
     * or the first button on the lower row of controller buttons. */
    public static final int KEYCODE_BUTTON_X        = 99;
    /** Key code constant: Y Button key.
     * On a game controller, the Y button should be either the button labeled Y
     * or the second button on the lower row of controller buttons. */
    public static final int KEYCODE_BUTTON_Y        = 100;
    /** Key code constant: Z Button key.
     * On a game controller, the Z button should be either the button labeled Z
     * or the third button on the lower row of controller buttons. */
    public static final int KEYCODE_BUTTON_Z        = 101;
    /** Key code constant: L1 Button key.
     * On a game controller, the L1 button should be either the button labeled L1 (or L)
     * or the top left trigger button. */
    public static final int KEYCODE_BUTTON_L1       = 102;
    /** Key code constant: R1 Button key.
     * On a game controller, the R1 button should be either the button labeled R1 (or R)
     * or the top right trigger button. */
    public static final int KEYCODE_BUTTON_R1       = 103;
    /** Key code constant: L2 Button key.
     * On a game controller, the L2 button should be either the button labeled L2
     * or the bottom left trigger button. */
    public static final int KEYCODE_BUTTON_L2       = 104;
    /** Key code constant: R2 Button key.
     * On a game controller, the R2 button should be either the button labeled R2
     * or the bottom right trigger button. */
    public static final int KEYCODE_BUTTON_R2       = 105;
    /** Key code constant: Left Thumb Button key.
     * On a game controller, the left thumb button indicates that the left (or only)
     * joystick is pressed. */
    public static final int KEYCODE_BUTTON_THUMBL   = 106;
    /** Key code constant: Right Thumb Button key.
     * On a game controller, the right thumb button indicates that the right
     * joystick is pressed. */
    public static final int KEYCODE_BUTTON_THUMBR   = 107;
    /** Key code constant: Start Button key.
     * On a game controller, the button labeled Start. */
    public static final int KEYCODE_BUTTON_START    = 108;
    /** Key code constant: Select Button key.
     * On a game controller, the button labeled Select. */
    public static final int KEYCODE_BUTTON_SELECT   = 109;
    /** Key code constant: Mode Button key.
     * On a game controller, the button labeled Mode. */
    public static final int KEYCODE_BUTTON_MODE     = 110;
    /** Key code constant: Escape key. */
    public static final int KEYCODE_ESCAPE          = 111;
    /** Key code constant: Forward Delete key.
     * Deletes characters ahead of the insertion point, unlike {@link #KEYCODE_DEL}. */
    public static final int KEYCODE_FORWARD_DEL     = 112;
    /** Key code constant: Left Control modifier key. */
    public static final int KEYCODE_CTRL_LEFT       = 113;
    /** Key code constant: Right Control modifier key. */
    public static final int KEYCODE_CTRL_RIGHT      = 114;
    /** Key code constant: Caps Lock key. */
    public static final int KEYCODE_CAPS_LOCK       = 115;
    /** Key code constant: Scroll Lock key. */
    public static final int KEYCODE_SCROLL_LOCK     = 116;
    /** Key code constant: Left Meta modifier key. */
    public static final int KEYCODE_META_LEFT       = 117;
    /** Key code constant: Right Meta modifier key. */
    public static final int KEYCODE_META_RIGHT      = 118;
    /** Key code constant: Function modifier key. */
    public static final int KEYCODE_FUNCTION        = 119;
    /** Key code constant: System Request / Print Screen key. */
    public static final int KEYCODE_SYSRQ           = 120;
    /** Key code constant: Break / Pause key. */
    public static final int KEYCODE_BREAK           = 121;
    /** Key code constant: Home Movement key.
     * Used for scrolling or moving the cursor around to the start of a line
     * or to the top of a list. */
    public static final int KEYCODE_MOVE_HOME       = 122;
    /** Key code constant: End Movement key.
     * Used for scrolling or moving the cursor around to the end of a line
     * or to the bottom of a list. */
    public static final int KEYCODE_MOVE_END        = 123;
    /** Key code constant: Insert key.
     * Toggles insert / overwrite edit mode. */
    public static final int KEYCODE_INSERT          = 124;
    /** Key code constant: Forward key.
     * Navigates forward in the history stack.  Complement of {@link #KEYCODE_BACK}. */
    public static final int KEYCODE_FORWARD         = 125;
    /** Key code constant: Play media key. */
    public static final int KEYCODE_MEDIA_PLAY      = 126;
    /** Key code constant: Pause media key. */
    public static final int KEYCODE_MEDIA_PAUSE     = 127;
    /** Key code constant: Close media key.
     * May be used to close a CD tray, for example. */
    public static final int KEYCODE_MEDIA_CLOSE     = 128;
    /** Key code constant: Eject media key.
     * May be used to eject a CD tray, for example. */
    public static final int KEYCODE_MEDIA_EJECT     = 129;
    /** Key code constant: Record media key. */
    public static final int KEYCODE_MEDIA_RECORD    = 130;
    /** Key code constant: F1 key. */
    public static final int KEYCODE_F1              = 131;
    /** Key code constant: F2 key. */
    public static final int KEYCODE_F2              = 132;
    /** Key code constant: F3 key. */
    public static final int KEYCODE_F3              = 133;
    /** Key code constant: F4 key. */
    public static final int KEYCODE_F4              = 134;
    /** Key code constant: F5 key. */
    public static final int KEYCODE_F5              = 135;
    /** Key code constant: F6 key. */
    public static final int KEYCODE_F6              = 136;
    /** Key code constant: F7 key. */
    public static final int KEYCODE_F7              = 137;
    /** Key code constant: F8 key. */
    public static final int KEYCODE_F8              = 138;
    /** Key code constant: F9 key. */
    public static final int KEYCODE_F9              = 139;
    /** Key code constant: F10 key. */
    public static final int KEYCODE_F10             = 140;
    /** Key code constant: F11 key. */
    public static final int KEYCODE_F11             = 141;
    /** Key code constant: F12 key. */
    public static final int KEYCODE_F12             = 142;
    /** Key code constant: Num Lock key.
     * This is the Num Lock key; it is different from {@link #KEYCODE_NUM}.
     * This key alters the behavior of other keys on the numeric keypad. */
    public static final int KEYCODE_NUM_LOCK        = 143;
    /** Key code constant: Numeric keypad '0' key. */
    public static final int KEYCODE_NUMPAD_0        = 144;
    /** Key code constant: Numeric keypad '1' key. */
    public static final int KEYCODE_NUMPAD_1        = 145;
    /** Key code constant: Numeric keypad '2' key. */
    public static final int KEYCODE_NUMPAD_2        = 146;
    /** Key code constant: Numeric keypad '3' key. */
    public static final int KEYCODE_NUMPAD_3        = 147;
    /** Key code constant: Numeric keypad '4' key. */
    public static final int KEYCODE_NUMPAD_4        = 148;
    /** Key code constant: Numeric keypad '5' key. */
    public static final int KEYCODE_NUMPAD_5        = 149;
    /** Key code constant: Numeric keypad '6' key. */
    public static final int KEYCODE_NUMPAD_6        = 150;
    /** Key code constant: Numeric keypad '7' key. */
    public static final int KEYCODE_NUMPAD_7        = 151;
    /** Key code constant: Numeric keypad '8' key. */
    public static final int KEYCODE_NUMPAD_8        = 152;
    /** Key code constant: Numeric keypad '9' key. */
    public static final int KEYCODE_NUMPAD_9        = 153;
    /** Key code constant: Numeric keypad '/' key (for division). */
    public static final int KEYCODE_NUMPAD_DIVIDE   = 154;
    /** Key code constant: Numeric keypad '*' key (for multiplication). */
    public static final int KEYCODE_NUMPAD_MULTIPLY = 155;
    /** Key code constant: Numeric keypad '-' key (for subtraction). */
    public static final int KEYCODE_NUMPAD_SUBTRACT = 156;
    /** Key code constant: Numeric keypad '+' key (for addition). */
    public static final int KEYCODE_NUMPAD_ADD      = 157;
    /** Key code constant: Numeric keypad '.' key (for decimals or digit grouping). */
    public static final int KEYCODE_NUMPAD_DOT      = 158;
    /** Key code constant: Numeric keypad ',' key (for decimals or digit grouping). */
    public static final int KEYCODE_NUMPAD_COMMA    = 159;
    /** Key code constant: Numeric keypad Enter key. */
    public static final int KEYCODE_NUMPAD_ENTER    = 160;
    /** Key code constant: Numeric keypad '=' key. */
    public static final int KEYCODE_NUMPAD_EQUALS   = 161;
    /** Key code constant: Numeric keypad '(' key. */
    public static final int KEYCODE_NUMPAD_LEFT_PAREN = 162;
    /** Key code constant: Numeric keypad ')' key. */
    public static final int KEYCODE_NUMPAD_RIGHT_PAREN = 163;
    /** Key code constant: Volume Mute key.
     * Mutes the speaker, unlike {@link #KEYCODE_MUTE}.
     * This key should normally be implemented as a toggle such that the first press
     * mutes the speaker and the second press restores the original volume. */
    public static final int KEYCODE_VOLUME_MUTE     = 164;
    /** Key code constant: Info key.
     * Common on TV remotes to show additional information related to what is
     * currently being viewed. */
    public static final int KEYCODE_INFO            = 165;
    /** Key code constant: Channel up key.
     * On TV remotes, increments the television channel. */
    public static final int KEYCODE_CHANNEL_UP      = 166;
    /** Key code constant: Channel down key.
     * On TV remotes, decrements the television channel. */
    public static final int KEYCODE_CHANNEL_DOWN    = 167;
    /** Key code constant: Zoom in key. */
    public static final int KEYCODE_ZOOM_IN         = 168;
    /** Key code constant: Zoom out key. */
    public static final int KEYCODE_ZOOM_OUT        = 169;
    /** Key code constant: TV key.
     * On TV remotes, switches to viewing live TV. */
    public static final int KEYCODE_TV              = 170;
    /** Key code constant: Window key.
     * On TV remotes, toggles picture-in-picture mode or other windowing functions. */
    public static final int KEYCODE_WINDOW          = 171;
    /** Key code constant: Guide key.
     * On TV remotes, shows a programming guide. */
    public static final int KEYCODE_GUIDE           = 172;
    /** Key code constant: DVR key.
     * On some TV remotes, switches to a DVR mode for recorded shows. */
    public static final int KEYCODE_DVR             = 173;
    /** Key code constant: Bookmark key.
     * On some TV remotes, bookmarks content or web pages. */
    public static final int KEYCODE_BOOKMARK        = 174;
    /** Key code constant: Toggle captions key.
     * Switches the mode for closed-captioning text, for example during television shows. */
    public static final int KEYCODE_CAPTIONS        = 175;
    /** Key code constant: Settings key.
     * Starts the system settings activity. */
    public static final int KEYCODE_SETTINGS        = 176;
    /** Key code constant: TV power key.
     * On TV remotes, toggles the power on a television screen. */
    public static final int KEYCODE_TV_POWER        = 177;
    /** Key code constant: TV input key.
     * On TV remotes, switches the input on a television screen. */
    public static final int KEYCODE_TV_INPUT        = 178;
    /** Key code constant: Set-top-box power key.
     * On TV remotes, toggles the power on an external Set-top-box. */
    public static final int KEYCODE_STB_POWER       = 179;
    /** Key code constant: Set-top-box input key.
     * On TV remotes, switches the input mode on an external Set-top-box. */
    public static final int KEYCODE_STB_INPUT       = 180;
    /** Key code constant: A/V Receiver power key.
     * On TV remotes, toggles the power on an external A/V Receiver. */
    public static final int KEYCODE_AVR_POWER       = 181;
    /** Key code constant: A/V Receiver input key.
     * On TV remotes, switches the input mode on an external A/V Receiver. */
    public static final int KEYCODE_AVR_INPUT       = 182;
    /** Key code constant: Red "programmable" key.
     * On TV remotes, acts as a contextual/programmable key. */
    public static final int KEYCODE_PROG_RED        = 183;
    /** Key code constant: Green "programmable" key.
     * On TV remotes, actsas a contextual/programmable key. */
    public static final int KEYCODE_PROG_GREEN      = 184;
    /** Key code constant: Yellow "programmable" key.
     * On TV remotes, acts as a contextual/programmable key. */
    public static final int KEYCODE_PROG_YELLOW     = 185;
    /** Key code constant: Blue "programmable" key.
     * On TV remotes, acts as a contextual/programmable key. */
    public static final int KEYCODE_PROG_BLUE       = 186;
    /** Key code constant: App switch key.
     * Should bring up the application switcher dialog. */
    public static final int KEYCODE_APP_SWITCH      = 187;

    private static final int LAST_KEYCODE           = KEYCODE_APP_SWITCH;

    // NOTE: If you add a new keycode here you must also add it to:
    //  isSystem()
    //  native/include/android/keycodes.h
    //  frameworks/base/include/ui/KeycodeLabels.h
    //  external/webkit/WebKit/android/plugins/ANPKeyCodes.h
    //  frameworks/base/core/res/res/values/attrs.xml
    //  emulator?
    //
    //  Also Android currently does not reserve code ranges for vendor-
    //  specific key codes.  If you have new key codes to have, you
    //  MUST contribute a patch to the open source project to define
    //  those new codes.  This is intended to maintain a consistent
    //  set of key code definitions across all Android devices.

    // Symbolic names of all keys indexed by keycode.
    // There should be exactly LAST_KEYCODE + 1 entries in this table.
    private static final String[] KEYCODE_SYMBOLIC_NAMES = new String[] {
        "KEYCODE_UNKNOWN",
        "KEYCODE_SOFT_LEFT",
        "KEYCODE_SOFT_RIGHT",
        "KEYCODE_HOME",
        "KEYCODE_BACK",
        "KEYCODE_CALL",
        "KEYCODE_ENDCALL",
        "KEYCODE_0",
        "KEYCODE_1",
        "KEYCODE_2",
        "KEYCODE_3",
        "KEYCODE_4",
        "KEYCODE_5",
        "KEYCODE_6",
        "KEYCODE_7",
        "KEYCODE_8",
        "KEYCODE_9",
        "KEYCODE_STAR",
        "KEYCODE_POUND",
        "KEYCODE_DPAD_UP",
        "KEYCODE_DPAD_DOWN",
        "KEYCODE_DPAD_LEFT",
        "KEYCODE_DPAD_RIGHT",
        "KEYCODE_DPAD_CENTER",
        "KEYCODE_VOLUME_UP",
        "KEYCODE_VOLUME_DOWN",
        "KEYCODE_POWER",
        "KEYCODE_CAMERA",
        "KEYCODE_CLEAR",
        "KEYCODE_A",
        "KEYCODE_B",
        "KEYCODE_C",
        "KEYCODE_D",
        "KEYCODE_E",
        "KEYCODE_F",
        "KEYCODE_G",
        "KEYCODE_H",
        "KEYCODE_I",
        "KEYCODE_J",
        "KEYCODE_K",
        "KEYCODE_L",
        "KEYCODE_M",
        "KEYCODE_N",
        "KEYCODE_O",
        "KEYCODE_P",
        "KEYCODE_Q",
        "KEYCODE_R",
        "KEYCODE_S",
        "KEYCODE_T",
        "KEYCODE_U",
        "KEYCODE_V",
        "KEYCODE_W",
        "KEYCODE_X",
        "KEYCODE_Y",
        "KEYCODE_Z",
        "KEYCODE_COMMA",
        "KEYCODE_PERIOD",
        "KEYCODE_ALT_LEFT",
        "KEYCODE_ALT_RIGHT",
        "KEYCODE_SHIFT_LEFT",
        "KEYCODE_SHIFT_RIGHT",
        "KEYCODE_TAB",
        "KEYCODE_SPACE",
        "KEYCODE_SYM",
        "KEYCODE_EXPLORER",
        "KEYCODE_ENVELOPE",
        "KEYCODE_ENTER",
        "KEYCODE_DEL",
        "KEYCODE_GRAVE",
        "KEYCODE_MINUS",
        "KEYCODE_EQUALS",
        "KEYCODE_LEFT_BRACKET",
        "KEYCODE_RIGHT_BRACKET",
        "KEYCODE_BACKSLASH",
        "KEYCODE_SEMICOLON",
        "KEYCODE_APOSTROPHE",
        "KEYCODE_SLASH",
        "KEYCODE_AT",
        "KEYCODE_NUM",
        "KEYCODE_HEADSETHOOK",
        "KEYCODE_FOCUS",
        "KEYCODE_PLUS",
        "KEYCODE_MENU",
        "KEYCODE_NOTIFICATION",
        "KEYCODE_SEARCH",
        "KEYCODE_MEDIA_PLAY_PAUSE",
        "KEYCODE_MEDIA_STOP",
        "KEYCODE_MEDIA_NEXT",
        "KEYCODE_MEDIA_PREVIOUS",
        "KEYCODE_MEDIA_REWIND",
        "KEYCODE_MEDIA_FAST_FORWARD",
        "KEYCODE_MUTE",
        "KEYCODE_PAGE_UP",
        "KEYCODE_PAGE_DOWN",
        "KEYCODE_PICTSYMBOLS",
        "KEYCODE_SWITCH_CHARSET",
        "KEYCODE_BUTTON_A",
        "KEYCODE_BUTTON_B",
        "KEYCODE_BUTTON_C",
        "KEYCODE_BUTTON_X",
        "KEYCODE_BUTTON_Y",
        "KEYCODE_BUTTON_Z",
        "KEYCODE_BUTTON_L1",
        "KEYCODE_BUTTON_R1",
        "KEYCODE_BUTTON_L2",
        "KEYCODE_BUTTON_R2",
        "KEYCODE_BUTTON_THUMBL",
        "KEYCODE_BUTTON_THUMBR",
        "KEYCODE_BUTTON_START",
        "KEYCODE_BUTTON_SELECT",
        "KEYCODE_BUTTON_MODE",
        "KEYCODE_ESCAPE",
        "KEYCODE_FORWARD_DEL",
        "KEYCODE_CTRL_LEFT",
        "KEYCODE_CTRL_RIGHT",
        "KEYCODE_CAPS_LOCK",
        "KEYCODE_SCROLL_LOCK",
        "KEYCODE_META_LEFT",
        "KEYCODE_META_RIGHT",
        "KEYCODE_FUNCTION",
        "KEYCODE_SYSRQ",
        "KEYCODE_BREAK",
        "KEYCODE_MOVE_HOME",
        "KEYCODE_MOVE_END",
        "KEYCODE_INSERT",
        "KEYCODE_FORWARD",
        "KEYCODE_MEDIA_PLAY",
        "KEYCODE_MEDIA_PAUSE",
        "KEYCODE_MEDIA_CLOSE",
        "KEYCODE_MEDIA_EJECT",
        "KEYCODE_MEDIA_RECORD",
        "KEYCODE_F1",
        "KEYCODE_F2",
        "KEYCODE_F3",
        "KEYCODE_F4",
        "KEYCODE_F5",
        "KEYCODE_F6",
        "KEYCODE_F7",
        "KEYCODE_F8",
        "KEYCODE_F9",
        "KEYCODE_F10",
        "KEYCODE_F11",
        "KEYCODE_F12",
        "KEYCODE_NUM_LOCK",
        "KEYCODE_NUMPAD_0",
        "KEYCODE_NUMPAD_1",
        "KEYCODE_NUMPAD_2",
        "KEYCODE_NUMPAD_3",
        "KEYCODE_NUMPAD_4",
        "KEYCODE_NUMPAD_5",
        "KEYCODE_NUMPAD_6",
        "KEYCODE_NUMPAD_7",
        "KEYCODE_NUMPAD_8",
        "KEYCODE_NUMPAD_9",
        "KEYCODE_NUMPAD_DIVIDE",
        "KEYCODE_NUMPAD_MULTIPLY",
        "KEYCODE_MUMPAD_SUBTRACT",
        "KEYCODE_NUMPAD_ADD",
        "KEYCODE_NUMPAD_DOT",
        "KEYCODE_NUMPAD_COMMA",
        "KEYCODE_NUMPAD_ENTER",
        "KEYCODE_NUMPAD_EQUALS",
        "KEYCODE_NUMPAD_LEFT_PAREN",
        "KEYCODE_NUMPAD_RIGHT_PAREN",
        "KEYCODE_VOLUME_MUTE",
        "KEYCODE_INFO",
        "KEYCODE_CHANNEL_UP",
        "KEYCODE_CHANNEL_DOWN",
        "KEYCODE_ZOOM_IN",
        "KEYCODE_ZOOM_OUT",
        "KEYCODE_TV",
        "KEYCODE_WINDOW",
        "KEYCODE_GUIDE",
        "KEYCODE_DVR",
        "KEYCODE_BOOKMARK",
        "KEYCODE_CAPTIONS",
        "KEYCODE_SETTINGS",
        "KEYCODE_TV_POWER",
        "KEYCODE_TV_INPUT",
        "KEYCODE_STB_INPUT",
        "KEYCODE_STB_POWER",
        "KEYCODE_AVR_POWER",
        "KEYCODE_AVR_INPUT",
        "KEYCODE_PROG_RED",
        "KEYCODE_PROG_GREEN",
        "KEYCODE_PROG_YELLOW",
        "KEYCODE_PROG_BLUE",
        "KEYCODE_APP_SWITCH",
    };

    // Symbolic names of all metakeys in bit order from least significant to most significant.
    // Accordingly there are exactly 32 values in this table.
    private static final String[] META_SYMBOLIC_NAMES = new String[] {
        "META_SHIFT_ON",
        "META_ALT_ON",
        "META_SYM_ON",
        "META_FUNCTION_ON",
        "META_ALT_LEFT_ON",
        "META_ALT_RIGHT_ON",
        "META_SHIFT_LEFT_ON",
        "META_SHIFT_RIGHT_ON",
        "META_CAP_LOCKED",
        "META_ALT_LOCKED",
        "META_SYM_LOCKED",
        "0x00000800",
        "META_CTRL_ON",
        "META_CTRL_LEFT_ON",
        "META_CTRL_RIGHT_ON",
        "0x00008000",
        "META_META_ON",
        "META_META_LEFT_ON",
        "META_META_RIGHT_ON",
        "0x00080000",
        "META_CAPS_LOCK_ON",
        "META_NUM_LOCK_ON",
        "META_SCROLL_LOCK_ON",
        "0x00800000",
        "0x01000000",
        "0x02000000",
        "0x04000000",
        "0x08000000",
        "0x10000000",
        "0x20000000",
        "0x40000000",
        "0x80000000",
    };

    /**
     * @deprecated There are now more than MAX_KEYCODE keycodes.
     * Use {@link #getMaxKeyCode()} instead.
     */
    @Deprecated
    public static final int MAX_KEYCODE             = 84;

    /**
     * {@link #getAction} value: the key has been pressed down.
     */
    public static final int ACTION_DOWN             = 0;
    /**
     * {@link #getAction} value: the key has been released.
     */
    public static final int ACTION_UP               = 1;
    /**
     * {@link #getAction} value: multiple duplicate key events have
     * occurred in a row, or a complex string is being delivered.  If the
     * key code is not {#link {@link #KEYCODE_UNKNOWN} then the
     * {#link {@link #getRepeatCount()} method returns the number of times
     * the given key code should be executed.
     * Otherwise, if the key code is {@link #KEYCODE_UNKNOWN}, then
     * this is a sequence of characters as returned by {@link #getCharacters}.
     */
    public static final int ACTION_MULTIPLE         = 2;

    /**
     * SHIFT key locked in CAPS mode.
     * Reserved for use by {@link MetaKeyKeyListener} for a published constant in its API.
     * @hide
     */
    public static final int META_CAP_LOCKED = 0x100;

    /**
     * ALT key locked.
     * Reserved for use by {@link MetaKeyKeyListener} for a published constant in its API.
     * @hide
     */
    public static final int META_ALT_LOCKED = 0x200;

    /**
     * SYM key locked.
     * Reserved for use by {@link MetaKeyKeyListener} for a published constant in its API.
     * @hide
     */
    public static final int META_SYM_LOCKED = 0x400;

    /**
     * Text is in selection mode.
     * Reserved for use by {@link MetaKeyKeyListener} for a private unpublished constant
     * in its API that is currently being retained for legacy reasons.
     * @hide
     */
    public static final int META_SELECTING = 0x800;

    /**
     * <p>This mask is used to check whether one of the ALT meta keys is pressed.</p>
     *
     * @see #isAltPressed()
     * @see #getMetaState()
     * @see #KEYCODE_ALT_LEFT
     * @see #KEYCODE_ALT_RIGHT
     */
    public static final int META_ALT_ON = 0x02;

    /**
     * <p>This mask is used to check whether the left ALT meta key is pressed.</p>
     *
     * @see #isAltPressed()
     * @see #getMetaState()
     * @see #KEYCODE_ALT_LEFT
     */
    public static final int META_ALT_LEFT_ON = 0x10;

    /**
     * <p>This mask is used to check whether the right the ALT meta key is pressed.</p>
     *
     * @see #isAltPressed()
     * @see #getMetaState()
     * @see #KEYCODE_ALT_RIGHT
     */
    public static final int META_ALT_RIGHT_ON = 0x20;

    /**
     * <p>This mask is used to check whether one of the SHIFT meta keys is pressed.</p>
     *
     * @see #isShiftPressed()
     * @see #getMetaState()
     * @see #KEYCODE_SHIFT_LEFT
     * @see #KEYCODE_SHIFT_RIGHT
     */
    public static final int META_SHIFT_ON = 0x1;

    /**
     * <p>This mask is used to check whether the left SHIFT meta key is pressed.</p>
     *
     * @see #isShiftPressed()
     * @see #getMetaState()
     * @see #KEYCODE_SHIFT_LEFT
     */
    public static final int META_SHIFT_LEFT_ON = 0x40;

    /**
     * <p>This mask is used to check whether the right SHIFT meta key is pressed.</p>
     *
     * @see #isShiftPressed()
     * @see #getMetaState()
     * @see #KEYCODE_SHIFT_RIGHT
     */
    public static final int META_SHIFT_RIGHT_ON = 0x80;

    /**
     * <p>This mask is used to check whether the SYM meta key is pressed.</p>
     *
     * @see #isSymPressed()
     * @see #getMetaState()
     */
    public static final int META_SYM_ON = 0x4;

    /**
     * <p>This mask is used to check whether the FUNCTION meta key is pressed.</p>
     *
     * @see #isFunctionPressed()
     * @see #getMetaState()
     */
    public static final int META_FUNCTION_ON = 0x8;

    /**
     * <p>This mask is used to check whether one of the CTRL meta keys is pressed.</p>
     *
     * @see #isCtrlPressed()
     * @see #getMetaState()
     * @see #KEYCODE_CTRL_LEFT
     * @see #KEYCODE_CTRL_RIGHT
     */
    public static final int META_CTRL_ON = 0x1000;

    /**
     * <p>This mask is used to check whether the left CTRL meta key is pressed.</p>
     *
     * @see #isCtrlPressed()
     * @see #getMetaState()
     * @see #KEYCODE_CTRL_LEFT
     */
    public static final int META_CTRL_LEFT_ON = 0x2000;

    /**
     * <p>This mask is used to check whether the right CTRL meta key is pressed.</p>
     *
     * @see #isCtrlPressed()
     * @see #getMetaState()
     * @see #KEYCODE_CTRL_RIGHT
     */
    public static final int META_CTRL_RIGHT_ON = 0x4000;

    /**
     * <p>This mask is used to check whether one of the META meta keys is pressed.</p>
     *
     * @see #isMetaPressed()
     * @see #getMetaState()
     * @see #KEYCODE_META_LEFT
     * @see #KEYCODE_META_RIGHT
     */
    public static final int META_META_ON = 0x10000;

    /**
     * <p>This mask is used to check whether the left META meta key is pressed.</p>
     *
     * @see #isMetaPressed()
     * @see #getMetaState()
     * @see #KEYCODE_META_LEFT
     */
    public static final int META_META_LEFT_ON = 0x20000;

    /**
     * <p>This mask is used to check whether the right META meta key is pressed.</p>
     *
     * @see #isMetaPressed()
     * @see #getMetaState()
     * @see #KEYCODE_META_RIGHT
     */
    public static final int META_META_RIGHT_ON = 0x40000;

    /**
     * <p>This mask is used to check whether the CAPS LOCK meta key is on.</p>
     *
     * @see #isCapsLockOn()
     * @see #getMetaState()
     * @see #KEYCODE_CAPS_LOCK
     */
    public static final int META_CAPS_LOCK_ON = 0x100000;

    /**
     * <p>This mask is used to check whether the NUM LOCK meta key is on.</p>
     *
     * @see #isNumLockOn()
     * @see #getMetaState()
     * @see #KEYCODE_NUM_LOCK
     */
    public static final int META_NUM_LOCK_ON = 0x200000;

    /**
     * <p>This mask is used to check whether the SCROLL LOCK meta key is on.</p>
     *
     * @see #isScrollLockOn()
     * @see #getMetaState()
     * @see #KEYCODE_SCROLL_LOCK
     */
    public static final int META_SCROLL_LOCK_ON = 0x400000;

    /** {@hide} */
    public static final int META_SHIFT_MASK = META_SHIFT_ON
            | META_SHIFT_LEFT_ON | META_SHIFT_RIGHT_ON;

    /** {@hide} */
    public static final int META_ALT_MASK = META_ALT_ON
            | META_ALT_LEFT_ON | META_ALT_RIGHT_ON;

    /** {@hide} */
    public static final int META_CTRL_MASK = META_CTRL_ON
            | META_CTRL_LEFT_ON | META_CTRL_RIGHT_ON;

    /** {@hide} */
    public static final int META_META_MASK = META_ALT_ON
            | META_META_LEFT_ON | META_META_RIGHT_ON;

    /**
     * This mask is set if the device woke because of this key event.
     */
    public static final int FLAG_WOKE_HERE = 0x1;
    
    /**
     * This mask is set if the key event was generated by a software keyboard.
     */
    public static final int FLAG_SOFT_KEYBOARD = 0x2;
    
    /**
     * This mask is set if we don't want the key event to cause us to leave
     * touch mode.
     */
    public static final int FLAG_KEEP_TOUCH_MODE = 0x4;
    
    /**
     * This mask is set if an event was known to come from a trusted part
     * of the system.  That is, the event is known to come from the user,
     * and could not have been spoofed by a third party component.
     */
    public static final int FLAG_FROM_SYSTEM = 0x8;
    
    /**
     * This mask is used for compatibility, to identify enter keys that are
     * coming from an IME whose enter key has been auto-labelled "next" or
     * "done".  This allows TextView to dispatch these as normal enter keys
     * for old applications, but still do the appropriate action when
     * receiving them.
     */
    public static final int FLAG_EDITOR_ACTION = 0x10;
    
    /**
     * When associated with up key events, this indicates that the key press
     * has been canceled.  Typically this is used with virtual touch screen
     * keys, where the user can slide from the virtual key area on to the
     * display: in that case, the application will receive a canceled up
     * event and should not perform the action normally associated with the
     * key.  Note that for this to work, the application can not perform an
     * action for a key until it receives an up or the long press timeout has
     * expired. 
     */
    public static final int FLAG_CANCELED = 0x20;
    
    /**
     * This key event was generated by a virtual (on-screen) hard key area.
     * Typically this is an area of the touchscreen, outside of the regular
     * display, dedicated to "hardware" buttons.
     */
    public static final int FLAG_VIRTUAL_HARD_KEY = 0x40;
    
    /**
     * This flag is set for the first key repeat that occurs after the
     * long press timeout.
     */
    public static final int FLAG_LONG_PRESS = 0x80;
    
    /**
     * Set when a key event has {@link #FLAG_CANCELED} set because a long
     * press action was executed while it was down. 
     */
    public static final int FLAG_CANCELED_LONG_PRESS = 0x100;
    
    /**
     * Set for {@link #ACTION_UP} when this event's key code is still being
     * tracked from its initial down.  That is, somebody requested that tracking
     * started on the key down and a long press has not caused
     * the tracking to be canceled.
     */
    public static final int FLAG_TRACKING = 0x200;

    /**
     * Set when a key event has been synthesized to implement default behavior
     * for an event that the application did not handle.
     * Fallback key events are generated by unhandled trackball motions
     * (to emulate a directional keypad) and by certain unhandled key presses
     * that are declared in the key map (such as special function numeric keypad
     * keys when numlock is off).
     */
    public static final int FLAG_FALLBACK = 0x400;

    /**
     * Private control to determine when an app is tracking a key sequence.
     * @hide
     */
    public static final int FLAG_START_TRACKING = 0x40000000;
    
    /**
     * Returns the maximum keycode.
     */
    public static int getMaxKeyCode() {
        return LAST_KEYCODE;
    }

    /**
     * Get the character that is produced by putting accent on the character
     * c.
     * For example, getDeadChar('`', 'e') returns &egrave;.
     */
    public static int getDeadChar(int accent, int c) {
        return KeyCharacterMap.getDeadChar(accent, c);
    }
    
    static final boolean DEBUG = false;
    static final String TAG = "KeyEvent";

    private static final int MAX_RECYCLED = 10;
    private static final Object gRecyclerLock = new Object();
    private static int gRecyclerUsed;
    private static KeyEvent gRecyclerTop;

    private KeyEvent mNext;
    private boolean mRecycled;

    private int mMetaState;
    private int mAction;
    private int mKeyCode;
    private int mScanCode;
    private int mRepeatCount;
    private int mFlags;
    private long mDownTime;
    private long mEventTime;
    private String mCharacters;

    public interface Callback {
        /**
         * Called when a key down event has occurred.  If you return true,
         * you can first call {@link KeyEvent#startTracking()
         * KeyEvent.startTracking()} to have the framework track the event
         * through its {@link #onKeyUp(int, KeyEvent)} and also call your
         * {@link #onKeyLongPress(int, KeyEvent)} if it occurs.
         * 
         * @param keyCode The value in event.getKeyCode().
         * @param event Description of the key event.
         * 
         * @return If you handled the event, return true.  If you want to allow
         *         the event to be handled by the next receiver, return false.
         */
        boolean onKeyDown(int keyCode, KeyEvent event);

        /**
         * Called when a long press has occurred.  If you return true,
         * the final key up will have {@link KeyEvent#FLAG_CANCELED} and
         * {@link KeyEvent#FLAG_CANCELED_LONG_PRESS} set.  Note that in
         * order to receive this callback, someone in the event change
         * <em>must</em> return true from {@link #onKeyDown} <em>and</em>
         * call {@link KeyEvent#startTracking()} on the event.
         * 
         * @param keyCode The value in event.getKeyCode().
         * @param event Description of the key event.
         * 
         * @return If you handled the event, return true.  If you want to allow
         *         the event to be handled by the next receiver, return false.
         */
        boolean onKeyLongPress(int keyCode, KeyEvent event);

        /**
         * Called when a key up event has occurred.
         * 
         * @param keyCode The value in event.getKeyCode().
         * @param event Description of the key event.
         * 
         * @return If you handled the event, return true.  If you want to allow
         *         the event to be handled by the next receiver, return false.
         */
        boolean onKeyUp(int keyCode, KeyEvent event);

        /**
         * Called when multiple down/up pairs of the same key have occurred
         * in a row.
         * 
         * @param keyCode The value in event.getKeyCode().
         * @param count Number of pairs as returned by event.getRepeatCount().
         * @param event Description of the key event.
         * 
         * @return If you handled the event, return true.  If you want to allow
         *         the event to be handled by the next receiver, return false.
         */
        boolean onKeyMultiple(int keyCode, int count, KeyEvent event);
    }

    static {
        if (META_SYMBOLIC_NAMES.length != 32) {
            throw new IllegalStateException(
                    "META_SYMBOLIC_NAMES array should contain exactly 32 entries.");
        }
        if (KEYCODE_SYMBOLIC_NAMES.length != LAST_KEYCODE + 1) {
            throw new IllegalStateException(
                    "KEYCODE_SYMBOLIC_NAMES array is out of sync with the keycode constants.");
        }
    }

    private KeyEvent() {
    }

    /**
     * Create a new key event.
     * 
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     */
    public KeyEvent(int action, int code) {
        mAction = action;
        mKeyCode = code;
        mRepeatCount = 0;
        mDeviceId = KeyCharacterMap.VIRTUAL_KEYBOARD;
    }

    /**
     * Create a new key event.
     * 
     * @param downTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this key code originally went down.
     * @param eventTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event happened.
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     * @param repeat A repeat count for down events (> 0 if this is after the
     * initial down) or event count for multiple events.
     */
    public KeyEvent(long downTime, long eventTime, int action,
                    int code, int repeat) {
        mDownTime = downTime;
        mEventTime = eventTime;
        mAction = action;
        mKeyCode = code;
        mRepeatCount = repeat;
        mDeviceId = KeyCharacterMap.VIRTUAL_KEYBOARD;
    }

    /**
     * Create a new key event.
     * 
     * @param downTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this key code originally went down.
     * @param eventTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event happened.
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     * @param repeat A repeat count for down events (> 0 if this is after the
     * initial down) or event count for multiple events.
     * @param metaState Flags indicating which meta keys are currently pressed.
     */
    public KeyEvent(long downTime, long eventTime, int action,
                    int code, int repeat, int metaState) {
        mDownTime = downTime;
        mEventTime = eventTime;
        mAction = action;
        mKeyCode = code;
        mRepeatCount = repeat;
        mMetaState = metaState;
        mDeviceId = KeyCharacterMap.VIRTUAL_KEYBOARD;
    }

    /**
     * Create a new key event.
     * 
     * @param downTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this key code originally went down.
     * @param eventTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event happened.
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     * @param repeat A repeat count for down events (> 0 if this is after the
     * initial down) or event count for multiple events.
     * @param metaState Flags indicating which meta keys are currently pressed.
     * @param deviceId The device ID that generated the key event.
     * @param scancode Raw device scan code of the event.
     */
    public KeyEvent(long downTime, long eventTime, int action,
                    int code, int repeat, int metaState,
                    int deviceId, int scancode) {
        mDownTime = downTime;
        mEventTime = eventTime;
        mAction = action;
        mKeyCode = code;
        mRepeatCount = repeat;
        mMetaState = metaState;
        mDeviceId = deviceId;
        mScanCode = scancode;
    }

    /**
     * Create a new key event.
     * 
     * @param downTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this key code originally went down.
     * @param eventTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event happened.
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     * @param repeat A repeat count for down events (> 0 if this is after the
     * initial down) or event count for multiple events.
     * @param metaState Flags indicating which meta keys are currently pressed.
     * @param deviceId The device ID that generated the key event.
     * @param scancode Raw device scan code of the event.
     * @param flags The flags for this key event
     */
    public KeyEvent(long downTime, long eventTime, int action,
                    int code, int repeat, int metaState,
                    int deviceId, int scancode, int flags) {
        mDownTime = downTime;
        mEventTime = eventTime;
        mAction = action;
        mKeyCode = code;
        mRepeatCount = repeat;
        mMetaState = metaState;
        mDeviceId = deviceId;
        mScanCode = scancode;
        mFlags = flags;
    }

    /**
     * Create a new key event.
     * 
     * @param downTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this key code originally went down.
     * @param eventTime The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event happened.
     * @param action Action code: either {@link #ACTION_DOWN},
     * {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * @param code The key code.
     * @param repeat A repeat count for down events (> 0 if this is after the
     * initial down) or event count for multiple events.
     * @param metaState Flags indicating which meta keys are currently pressed.
     * @param deviceId The device ID that generated the key event.
     * @param scancode Raw device scan code of the event.
     * @param flags The flags for this key event
     * @param source The input source such as {@link InputDevice#SOURCE_KEYBOARD}.
     */
    public KeyEvent(long downTime, long eventTime, int action,
                    int code, int repeat, int metaState,
                    int deviceId, int scancode, int flags, int source) {
        mDownTime = downTime;
        mEventTime = eventTime;
        mAction = action;
        mKeyCode = code;
        mRepeatCount = repeat;
        mMetaState = metaState;
        mDeviceId = deviceId;
        mScanCode = scancode;
        mFlags = flags;
        mSource = source;
    }

    /**
     * Create a new key event for a string of characters.  The key code,
     * action, repeat count and source will automatically be set to
     * {@link #KEYCODE_UNKNOWN}, {@link #ACTION_MULTIPLE}, 0, and
     * {@link InputDevice#SOURCE_KEYBOARD} for you.
     * 
     * @param time The time (in {@link android.os.SystemClock#uptimeMillis})
     * at which this event occured.
     * @param characters The string of characters.
     * @param deviceId The device ID that generated the key event.
     * @param flags The flags for this key event
     */
    public KeyEvent(long time, String characters, int deviceId, int flags) {
        mDownTime = time;
        mEventTime = time;
        mCharacters = characters;
        mAction = ACTION_MULTIPLE;
        mKeyCode = KEYCODE_UNKNOWN;
        mRepeatCount = 0;
        mDeviceId = deviceId;
        mFlags = flags;
        mSource = InputDevice.SOURCE_KEYBOARD;
    }

    /**
     * Make an exact copy of an existing key event.
     */
    public KeyEvent(KeyEvent origEvent) {
        mDownTime = origEvent.mDownTime;
        mEventTime = origEvent.mEventTime;
        mAction = origEvent.mAction;
        mKeyCode = origEvent.mKeyCode;
        mRepeatCount = origEvent.mRepeatCount;
        mMetaState = origEvent.mMetaState;
        mDeviceId = origEvent.mDeviceId;
        mSource = origEvent.mSource;
        mScanCode = origEvent.mScanCode;
        mFlags = origEvent.mFlags;
        mCharacters = origEvent.mCharacters;
    }

    /**
     * Copy an existing key event, modifying its time and repeat count.
     * 
     * @deprecated Use {@link #changeTimeRepeat(KeyEvent, long, int)}
     * instead.
     * 
     * @param origEvent The existing event to be copied.
     * @param eventTime The new event time
     * (in {@link android.os.SystemClock#uptimeMillis}) of the event.
     * @param newRepeat The new repeat count of the event.
     */
    @Deprecated
    public KeyEvent(KeyEvent origEvent, long eventTime, int newRepeat) {
        mDownTime = origEvent.mDownTime;
        mEventTime = eventTime;
        mAction = origEvent.mAction;
        mKeyCode = origEvent.mKeyCode;
        mRepeatCount = newRepeat;
        mMetaState = origEvent.mMetaState;
        mDeviceId = origEvent.mDeviceId;
        mSource = origEvent.mSource;
        mScanCode = origEvent.mScanCode;
        mFlags = origEvent.mFlags;
        mCharacters = origEvent.mCharacters;
    }

    private static KeyEvent obtain() {
        final KeyEvent ev;
        synchronized (gRecyclerLock) {
            ev = gRecyclerTop;
            if (ev == null) {
                return new KeyEvent();
            }
            gRecyclerTop = ev.mNext;
            gRecyclerUsed -= 1;
        }
        ev.mRecycled = false;
        ev.mNext = null;
        return ev;
    }

    /**
     * Obtains a (potentially recycled) key event.
     *
     * @hide
     */
    public static KeyEvent obtain(long downTime, long eventTime, int action,
                    int code, int repeat, int metaState,
                    int deviceId, int scancode, int flags, int source, String characters) {
        KeyEvent ev = obtain();
        ev.mDownTime = downTime;
        ev.mEventTime = eventTime;
        ev.mAction = action;
        ev.mKeyCode = code;
        ev.mRepeatCount = repeat;
        ev.mMetaState = metaState;
        ev.mDeviceId = deviceId;
        ev.mScanCode = scancode;
        ev.mFlags = flags;
        ev.mSource = source;
        ev.mCharacters = characters;
        return ev;
    }

    /**
     * Recycles a key event.
     * Key events should only be recycled if they are owned by the system since user
     * code expects them to be essentially immutable, "tracking" notwithstanding.
     *
     * @hide
     */
    public final void recycle() {
        if (mRecycled) {
            throw new RuntimeException(toString() + " recycled twice!");
        }
        mRecycled = true;
        mCharacters = null;

        synchronized (gRecyclerLock) {
            if (gRecyclerUsed < MAX_RECYCLED) {
                gRecyclerUsed++;
                mNext = gRecyclerTop;
                gRecyclerTop = this;
            }
        }
    }

    /**
     * Create a new key event that is the same as the given one, but whose
     * event time and repeat count are replaced with the given value.
     * 
     * @param event The existing event to be copied.  This is not modified.
     * @param eventTime The new event time
     * (in {@link android.os.SystemClock#uptimeMillis}) of the event.
     * @param newRepeat The new repeat count of the event.
     */
    public static KeyEvent changeTimeRepeat(KeyEvent event, long eventTime,
            int newRepeat) {
        return new KeyEvent(event, eventTime, newRepeat);
    }
    
    /**
     * Create a new key event that is the same as the given one, but whose
     * event time and repeat count are replaced with the given value.
     * 
     * @param event The existing event to be copied.  This is not modified.
     * @param eventTime The new event time
     * (in {@link android.os.SystemClock#uptimeMillis}) of the event.
     * @param newRepeat The new repeat count of the event.
     * @param newFlags New flags for the event, replacing the entire value
     * in the original event.
     */
    public static KeyEvent changeTimeRepeat(KeyEvent event, long eventTime,
            int newRepeat, int newFlags) {
        KeyEvent ret = new KeyEvent(event);
        ret.mEventTime = eventTime;
        ret.mRepeatCount = newRepeat;
        ret.mFlags = newFlags;
        return ret;
    }
    
    /**
     * Copy an existing key event, modifying its action.
     * 
     * @param origEvent The existing event to be copied.
     * @param action The new action code of the event.
     */
    private KeyEvent(KeyEvent origEvent, int action) {
        mDownTime = origEvent.mDownTime;
        mEventTime = origEvent.mEventTime;
        mAction = action;
        mKeyCode = origEvent.mKeyCode;
        mRepeatCount = origEvent.mRepeatCount;
        mMetaState = origEvent.mMetaState;
        mDeviceId = origEvent.mDeviceId;
        mSource = origEvent.mSource;
        mScanCode = origEvent.mScanCode;
        mFlags = origEvent.mFlags;
        // Don't copy mCharacters, since one way or the other we'll lose it
        // when changing the action.
    }

    /**
     * Create a new key event that is the same as the given one, but whose
     * action is replaced with the given value.
     * 
     * @param event The existing event to be copied.  This is not modified.
     * @param action The new action code of the event.
     */
    public static KeyEvent changeAction(KeyEvent event, int action) {
        return new KeyEvent(event, action);
    }
    
    /**
     * Create a new key event that is the same as the given one, but whose
     * flags are replaced with the given value.
     * 
     * @param event The existing event to be copied.  This is not modified.
     * @param flags The new flags constant.
     */
    public static KeyEvent changeFlags(KeyEvent event, int flags) {
        event = new KeyEvent(event);
        event.mFlags = flags;
        return event;
    }
    
    /**
     * Don't use in new code, instead explicitly check
     * {@link #getAction()}.
     * 
     * @return If the action is ACTION_DOWN, returns true; else false.
     *
     * @deprecated
     * @hide
     */
    @Deprecated public final boolean isDown() {
        return mAction == ACTION_DOWN;
    }

    /**
     * Is this a system key?  System keys can not be used for menu shortcuts.
     * 
     * TODO: this information should come from a table somewhere.
     * TODO: should the dpad keys be here?  arguably, because they also shouldn't be menu shortcuts
     */
    public final boolean isSystem() {
        return native_isSystemKey(mKeyCode);
    }

    /** @hide */
    public final boolean hasDefaultAction() {
        return native_hasDefaultAction(mKeyCode);
    }


    /**
     * <p>Returns the state of the meta keys.</p>
     *
     * @return an integer in which each bit set to 1 represents a pressed
     *         meta key
     *
     * @see #isAltPressed()
     * @see #isShiftPressed()
     * @see #isSymPressed()
     * @see #isCtrlPressed()
     * @see #isMetaPressed()
     * @see #isFunctionPressed()
     * @see #isCapsLockOn()
     * @see #isNumLockOn()
     * @see #isScrollLockOn()
     * @see #META_ALT_ON
     * @see #META_ALT_LEFT_ON
     * @see #META_ALT_RIGHT_ON
     * @see #META_SHIFT_ON
     * @see #META_SHIFT_LEFT_ON
     * @see #META_SHIFT_RIGHT_ON
     * @see #META_SYM_ON
     * @see #META_FUNCTION_ON
     * @see #META_CTRL_ON
     * @see #META_CTRL_LEFT_ON
     * @see #META_CTRL_RIGHT_ON
     * @see #META_META_ON
     * @see #META_META_LEFT_ON
     * @see #META_META_RIGHT_ON
     * @see #META_CAPS_LOCK_ON
     * @see #META_NUM_LOCK_ON
     * @see #META_SCROLL_LOCK_ON
     */
    public final int getMetaState() {
        return mMetaState;
    }

    /**
     * Returns the flags for this key event.
     *
     * @see #FLAG_WOKE_HERE
     */
    public final int getFlags() {
        return mFlags;
    }

    // Mask of all modifier key meta states.  Specifically excludes locked keys like caps lock.
    private static final int META_MODIFIER_MASK =
            META_SHIFT_ON | META_SHIFT_LEFT_ON | META_SHIFT_RIGHT_ON
            | META_ALT_ON | META_ALT_LEFT_ON | META_ALT_RIGHT_ON
            | META_CTRL_ON | META_CTRL_LEFT_ON | META_CTRL_RIGHT_ON
            | META_META_ON | META_META_LEFT_ON | META_META_RIGHT_ON
            | META_SYM_ON | META_FUNCTION_ON;

    // Mask of all lock key meta states.
    private static final int META_LOCK_MASK =
            META_CAPS_LOCK_ON | META_NUM_LOCK_ON | META_SCROLL_LOCK_ON;

    // Mask of all valid meta states.
    private static final int META_ALL_MASK = META_MODIFIER_MASK | META_LOCK_MASK;

    // Mask of all synthetic meta states that are reserved for API compatibility with
    // historical uses in MetaKeyKeyListener.
    private static final int META_SYNTHETIC_MASK =
            META_CAP_LOCKED | META_ALT_LOCKED | META_SYM_LOCKED | META_SELECTING;

    // Mask of all meta states that are not valid use in specifying a modifier key.
    // These bits are known to be used for purposes other than specifying modifiers.
    private static final int META_INVALID_MODIFIER_MASK =
            META_LOCK_MASK | META_SYNTHETIC_MASK;

    /**
     * Gets a mask that includes all valid modifier key meta state bits.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, the mask specifically excludes
     * {@link #META_CAPS_LOCK_ON}, {@link #META_SCROLL_LOCK_ON} and {@link #META_NUM_LOCK_ON}.
     * </p>
     *
     * @return The modifier meta state mask which is a combination of
     * {@link #META_SHIFT_ON}, {@link #META_SHIFT_LEFT_ON}, {@link #META_SHIFT_RIGHT_ON},
     * {@link #META_ALT_ON}, {@link #META_ALT_LEFT_ON}, {@link #META_ALT_RIGHT_ON},
     * {@link #META_CTRL_ON}, {@link #META_CTRL_LEFT_ON}, {@link #META_CTRL_RIGHT_ON},
     * {@link #META_META_ON}, {@link #META_META_LEFT_ON}, {@link #META_META_RIGHT_ON},
     * {@link #META_SYM_ON}, {@link #META_FUNCTION_ON}.
     */
    public static int getModifierMetaStateMask() {
        return META_MODIFIER_MASK;
    }

    /**
     * Returns true if this key code is a modifier key.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, this function return false
     * for those keys.
     * </p>
     *
     * @return True if the key code is one of
     * {@link #KEYCODE_SHIFT_LEFT} {@link #KEYCODE_SHIFT_RIGHT},
     * {@link #KEYCODE_ALT_LEFT}, {@link #KEYCODE_ALT_RIGHT},
     * {@link #KEYCODE_CTRL_LEFT}, {@link #KEYCODE_CTRL_RIGHT},
     * {@link #KEYCODE_META_LEFT}, or {@link #KEYCODE_META_RIGHT},
     * {@link #KEYCODE_SYM}, {@link #KEYCODE_NUM}, {@link #KEYCODE_FUNCTION}.
     */
    public static boolean isModifierKey(int keyCode) {
        switch (keyCode) {
            case KEYCODE_SHIFT_LEFT:
            case KEYCODE_SHIFT_RIGHT:
            case KEYCODE_ALT_LEFT:
            case KEYCODE_ALT_RIGHT:
            case KEYCODE_CTRL_LEFT:
            case KEYCODE_CTRL_RIGHT:
            case KEYCODE_META_LEFT:
            case KEYCODE_META_RIGHT:
            case KEYCODE_SYM:
            case KEYCODE_NUM:
            case KEYCODE_FUNCTION:
                return true;
            default:
                return false;
        }
    }

    /**
     * Normalizes the specified meta state.
     * <p>
     * The meta state is normalized such that if either the left or right modifier meta state
     * bits are set then the result will also include the universal bit for that modifier.
     * </p><p>
     * If the specified meta state contains {@link #META_ALT_LEFT_ON} then
     * the result will also contain {@link #META_ALT_ON} in addition to {@link #META_ALT_LEFT_ON}
     * and the other bits that were specified in the input.  The same is process is
     * performed for shift, control and meta.
     * </p><p>
     * If the specified meta state contains synthetic meta states defined by
     * {@link MetaKeyKeyListener}, then those states are translated here and the original
     * synthetic meta states are removed from the result.
     * {@link MetaKeyKeyListener#META_CAP_LOCKED} is translated to {@link #META_CAPS_LOCK_ON}.
     * {@link MetaKeyKeyListener#META_ALT_LOCKED} is translated to {@link #META_ALT_ON}.
     * {@link MetaKeyKeyListener#META_SYM_LOCKED} is translated to {@link #META_SYM_ON}.
     * </p><p>
     * Undefined meta state bits are removed.
     * </p>
     *
     * @param metaState The meta state.
     * @return The normalized meta state.
     */
    public static int normalizeMetaState(int metaState) {
        if ((metaState & (META_SHIFT_LEFT_ON | META_SHIFT_RIGHT_ON)) != 0) {
            metaState |= META_SHIFT_ON;
        }
        if ((metaState & (META_ALT_LEFT_ON | META_ALT_RIGHT_ON)) != 0) {
            metaState |= META_ALT_ON;
        }
        if ((metaState & (META_CTRL_LEFT_ON | META_CTRL_RIGHT_ON)) != 0) {
            metaState |= META_CTRL_ON;
        }
        if ((metaState & (META_META_LEFT_ON | META_META_RIGHT_ON)) != 0) {
            metaState |= META_META_ON;
        }
        if ((metaState & MetaKeyKeyListener.META_CAP_LOCKED) != 0) {
            metaState |= META_CAPS_LOCK_ON;
        }
        if ((metaState & MetaKeyKeyListener.META_ALT_LOCKED) != 0) {
            metaState |= META_ALT_ON;
        }
        if ((metaState & MetaKeyKeyListener.META_SYM_LOCKED) != 0) {
            metaState |= META_SYM_ON;
        }
        return metaState & META_ALL_MASK;
    }

    /**
     * Returns true if no modifiers keys are pressed according to the specified meta state.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, this function ignores
     * {@link #META_CAPS_LOCK_ON}, {@link #META_SCROLL_LOCK_ON} and {@link #META_NUM_LOCK_ON}.
     * </p><p>
     * The meta state is normalized prior to comparison using {@link #normalizeMetaState(int)}.
     * </p>
     *
     * @param metaState The meta state to consider.
     * @return True if no modifier keys are pressed.
     * @see #hasNoModifiers()
     */
    public static boolean metaStateHasNoModifiers(int metaState) {
        return (normalizeMetaState(metaState) & META_MODIFIER_MASK) == 0;
    }

    /**
     * Returns true if only the specified modifier keys are pressed according to
     * the specified meta state.  Returns false if a different combination of modifier
     * keys are pressed.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, this function ignores
     * {@link #META_CAPS_LOCK_ON}, {@link #META_SCROLL_LOCK_ON} and {@link #META_NUM_LOCK_ON}.
     * </p><p>
     * If the specified modifier mask includes directional modifiers, such as
     * {@link #META_SHIFT_LEFT_ON}, then this method ensures that the
     * modifier is pressed on that side.
     * If the specified modifier mask includes non-directional modifiers, such as
     * {@link #META_SHIFT_ON}, then this method ensures that the modifier
     * is pressed on either side.
     * If the specified modifier mask includes both directional and non-directional modifiers
     * for the same type of key, such as {@link #META_SHIFT_ON} and {@link #META_SHIFT_LEFT_ON},
     * then this method throws an illegal argument exception.
     * </p>
     *
     * @param metaState The meta state to consider.
     * @param modifiers The meta state of the modifier keys to check.  May be a combination
     * of modifier meta states as defined by {@link #getModifierMetaStateMask()}.  May be 0 to
     * ensure that no modifier keys are pressed.
     * @return True if only the specified modifier keys are pressed.
     * @throws IllegalArgumentException if the modifiers parameter contains invalid modifiers
     * @see #hasModifiers
     */
    public static boolean metaStateHasModifiers(int metaState, int modifiers) {
        // Note: For forward compatibility, we allow the parameter to contain meta states
        //       that we do not recognize but we explicitly disallow meta states that
        //       are not valid modifiers.
        if ((modifiers & META_INVALID_MODIFIER_MASK) != 0) {
            throw new IllegalArgumentException("modifiers must not contain "
                    + "META_CAPS_LOCK_ON, META_NUM_LOCK_ON, META_SCROLL_LOCK_ON, "
                    + "META_CAP_LOCKED, META_ALT_LOCKED, META_SYM_LOCKED, "
                    + "or META_SELECTING");
        }

        metaState = normalizeMetaState(metaState) & META_MODIFIER_MASK;
        metaState = metaStateFilterDirectionalModifiers(metaState, modifiers,
                META_SHIFT_ON, META_SHIFT_LEFT_ON, META_SHIFT_RIGHT_ON);
        metaState = metaStateFilterDirectionalModifiers(metaState, modifiers,
                META_ALT_ON, META_ALT_LEFT_ON, META_ALT_RIGHT_ON);
        metaState = metaStateFilterDirectionalModifiers(metaState, modifiers,
                META_CTRL_ON, META_CTRL_LEFT_ON, META_CTRL_RIGHT_ON);
        metaState = metaStateFilterDirectionalModifiers(metaState, modifiers,
                META_META_ON, META_META_LEFT_ON, META_META_RIGHT_ON);
        return metaState == modifiers;
    }

    private static int metaStateFilterDirectionalModifiers(int metaState,
            int modifiers, int basic, int left, int right) {
        final boolean wantBasic = (modifiers & basic) != 0;
        final int directional = left | right;
        final boolean wantLeftOrRight = (modifiers & directional) != 0;

        if (wantBasic) {
            if (wantLeftOrRight) {
                throw new IllegalArgumentException("modifiers must not contain "
                        + metaStateToString(basic) + " combined with "
                        + metaStateToString(left) + " or " + metaStateToString(right));
            }
            return metaState & ~directional;
        } else if (wantLeftOrRight) {
            return metaState & ~basic;
        } else {
            return metaState;
        }
    }

    /**
     * Returns true if no modifier keys are pressed.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, this function ignores
     * {@link #META_CAPS_LOCK_ON}, {@link #META_SCROLL_LOCK_ON} and {@link #META_NUM_LOCK_ON}.
     * </p><p>
     * The meta state is normalized prior to comparison using {@link #normalizeMetaState(int)}.
     * </p>
     *
     * @return True if no modifier keys are pressed.
     * @see #metaStateHasNoModifiers
     */
    public final boolean hasNoModifiers() {
        return metaStateHasNoModifiers(mMetaState);
    }

    /**
     * Returns true if only the specified modifiers keys are pressed.
     * Returns false if a different combination of modifier keys are pressed.
     * <p>
     * For the purposes of this function, {@link #KEYCODE_CAPS_LOCK},
     * {@link #KEYCODE_SCROLL_LOCK}, and {@link #KEYCODE_NUM_LOCK} are
     * not considered modifier keys.  Consequently, this function ignores
     * {@link #META_CAPS_LOCK_ON}, {@link #META_SCROLL_LOCK_ON} and {@link #META_NUM_LOCK_ON}.
     * </p><p>
     * If the specified modifier mask includes directional modifiers, such as
     * {@link #META_SHIFT_LEFT_ON}, then this method ensures that the
     * modifier is pressed on that side.
     * If the specified modifier mask includes non-directional modifiers, such as
     * {@link #META_SHIFT_ON}, then this method ensures that the modifier
     * is pressed on either side.
     * If the specified modifier mask includes both directional and non-directional modifiers
     * for the same type of key, such as {@link #META_SHIFT_ON} and {@link #META_SHIFT_LEFT_ON},
     * then this method throws an illegal argument exception.
     * </p>
     *
     * @param modifiers The meta state of the modifier keys to check.  May be a combination
     * of modifier meta states as defined by {@link #getModifierMetaStateMask()}.  May be 0 to
     * ensure that no modifier keys are pressed.
     * @return True if only the specified modifier keys are pressed.
     * @throws IllegalArgumentException if the modifiers parameter contains invalid modifiers
     * @see #metaStateHasModifiers
     */
    public final boolean hasModifiers(int modifiers) {
        return metaStateHasModifiers(mMetaState, modifiers);
    }

    /**
     * <p>Returns the pressed state of the ALT meta key.</p>
     *
     * @return true if the ALT key is pressed, false otherwise
     *
     * @see #KEYCODE_ALT_LEFT
     * @see #KEYCODE_ALT_RIGHT
     * @see #META_ALT_ON
     */
    public final boolean isAltPressed() {
        return (mMetaState & META_ALT_ON) != 0;
    }

    /**
     * <p>Returns the pressed state of the SHIFT meta key.</p>
     *
     * @return true if the SHIFT key is pressed, false otherwise
     *
     * @see #KEYCODE_SHIFT_LEFT
     * @see #KEYCODE_SHIFT_RIGHT
     * @see #META_SHIFT_ON
     */
    public final boolean isShiftPressed() {
        return (mMetaState & META_SHIFT_ON) != 0;
    }

    /**
     * <p>Returns the pressed state of the SYM meta key.</p>
     *
     * @return true if the SYM key is pressed, false otherwise
     *
     * @see #KEYCODE_SYM
     * @see #META_SYM_ON
     */
    public final boolean isSymPressed() {
        return (mMetaState & META_SYM_ON) != 0;
    }

    /**
     * <p>Returns the pressed state of the CTRL meta key.</p>
     *
     * @return true if the CTRL key is pressed, false otherwise
     *
     * @see #KEYCODE_CTRL_LEFT
     * @see #KEYCODE_CTRL_RIGHT
     * @see #META_CTRL_ON
     */
    public final boolean isCtrlPressed() {
        return (mMetaState & META_CTRL_ON) != 0;
    }

    /**
     * <p>Returns the pressed state of the META meta key.</p>
     *
     * @return true if the META key is pressed, false otherwise
     *
     * @see #KEYCODE_META_LEFT
     * @see #KEYCODE_META_RIGHT
     * @see #META_META_ON
     */
    public final boolean isMetaPressed() {
        return (mMetaState & META_META_ON) != 0;
    }

    /**
     * <p>Returns the pressed state of the FUNCTION meta key.</p>
     *
     * @return true if the FUNCTION key is pressed, false otherwise
     *
     * @see #KEYCODE_FUNCTION
     * @see #META_FUNCTION_ON
     */
    public final boolean isFunctionPressed() {
        return (mMetaState & META_FUNCTION_ON) != 0;
    }

    /**
     * <p>Returns the locked state of the CAPS LOCK meta key.</p>
     *
     * @return true if the CAPS LOCK key is on, false otherwise
     *
     * @see #KEYCODE_CAPS_LOCK
     * @see #META_CAPS_LOCK_ON
     */
    public final boolean isCapsLockOn() {
        return (mMetaState & META_CAPS_LOCK_ON) != 0;
    }

    /**
     * <p>Returns the locked state of the NUM LOCK meta key.</p>
     *
     * @return true if the NUM LOCK key is on, false otherwise
     *
     * @see #KEYCODE_NUM_LOCK
     * @see #META_NUM_LOCK_ON
     */
    public final boolean isNumLockOn() {
        return (mMetaState & META_NUM_LOCK_ON) != 0;
    }

    /**
     * <p>Returns the locked state of the SCROLL LOCK meta key.</p>
     *
     * @return true if the SCROLL LOCK key is on, false otherwise
     *
     * @see #KEYCODE_SCROLL_LOCK
     * @see #META_SCROLL_LOCK_ON
     */
    public final boolean isScrollLockOn() {
        return (mMetaState & META_SCROLL_LOCK_ON) != 0;
    }

    /**
     * Retrieve the action of this key event.  May be either
     * {@link #ACTION_DOWN}, {@link #ACTION_UP}, or {@link #ACTION_MULTIPLE}.
     * 
     * @return The event action: ACTION_DOWN, ACTION_UP, or ACTION_MULTIPLE.
     */
    public final int getAction() {
        return mAction;
    }

    /**
     * For {@link #ACTION_UP} events, indicates that the event has been
     * canceled as per {@link #FLAG_CANCELED}.
     */
    public final boolean isCanceled() {
        return (mFlags&FLAG_CANCELED) != 0;
    }
    
    /**
     * Call this during {@link Callback#onKeyDown} to have the system track
     * the key through its final up (possibly including a long press).  Note
     * that only one key can be tracked at a time -- if another key down
     * event is received while a previous one is being tracked, tracking is
     * stopped on the previous event.
     */
    public final void startTracking() {
        mFlags |= FLAG_START_TRACKING;
    }
    
    /**
     * For {@link #ACTION_UP} events, indicates that the event is still being
     * tracked from its initial down event as per
     * {@link #FLAG_TRACKING}.
     */
    public final boolean isTracking() {
        return (mFlags&FLAG_TRACKING) != 0;
    }
    
    /**
     * For {@link #ACTION_DOWN} events, indicates that the event has been
     * canceled as per {@link #FLAG_LONG_PRESS}.
     */
    public final boolean isLongPress() {
        return (mFlags&FLAG_LONG_PRESS) != 0;
    }
    
    /**
     * Retrieve the key code of the key event.  This is the physical key that
     * was pressed, <em>not</em> the Unicode character.
     * 
     * @return The key code of the event.
     */
    public final int getKeyCode() {
        return mKeyCode;
    }

    /**
     * For the special case of a {@link #ACTION_MULTIPLE} event with key
     * code of {@link #KEYCODE_UNKNOWN}, this is a raw string of characters
     * associated with the event.  In all other cases it is null.
     * 
     * @return Returns a String of 1 or more characters associated with
     * the event.
     */
    public final String getCharacters() {
        return mCharacters;
    }
    
    /**
     * Retrieve the hardware key id of this key event.  These values are not
     * reliable and vary from device to device.
     *
     * {@more}
     * Mostly this is here for debugging purposes.
     */
    public final int getScanCode() {
        return mScanCode;
    }

    /**
     * Retrieve the repeat count of the event.  For both key up and key down
     * events, this is the number of times the key has repeated with the first
     * down starting at 0 and counting up from there.  For multiple key
     * events, this is the number of down/up pairs that have occurred.
     * 
     * @return The number of times the key has repeated.
     */
    public final int getRepeatCount() {
        return mRepeatCount;
    }

    /**
     * Retrieve the time of the most recent key down event,
     * in the {@link android.os.SystemClock#uptimeMillis} time base.  If this
     * is a down event, this will be the same as {@link #getEventTime()}.
     * Note that when chording keys, this value is the down time of the
     * most recently pressed key, which may <em>not</em> be the same physical
     * key of this event.
     * 
     * @return Returns the most recent key down time, in the
     * {@link android.os.SystemClock#uptimeMillis} time base
     */
    public final long getDownTime() {
        return mDownTime;
    }

    /**
     * Retrieve the time this event occurred, 
     * in the {@link android.os.SystemClock#uptimeMillis} time base.
     * 
     * @return Returns the time this event occurred, 
     * in the {@link android.os.SystemClock#uptimeMillis} time base.
     */
    public final long getEventTime() {
        return mEventTime;
    }

    /**
     * Renamed to {@link #getDeviceId}.
     * 
     * @hide
     * @deprecated use {@link #getDeviceId()} instead.
     */
    @Deprecated
    public final int getKeyboardDevice() {
        return mDeviceId;
    }

    /**
     * Gets the {@link KeyCharacterMap} associated with the keyboard device.
     *
     * @return The associated key character map.
     * @throws {@link KeyCharacterMapUnavailableException} if the key character map
     * could not be loaded because it was malformed or the default key character map
     * is missing from the system.
     *
     * @see {@link KeyCharacterMap#load}
     */
    public final KeyCharacterMap getKeyCharacterMap() {
        return KeyCharacterMap.load(mDeviceId);
    }

    /**
     * Gets the primary character for this key.
     * In other words, the label that is physically printed on it.
     *
     * @return The display label character, or 0 if none (eg. for non-printing keys).
     */
    public char getDisplayLabel() {
        return getKeyCharacterMap().getDisplayLabel(mKeyCode);
    }
    
    /**
     * Gets the Unicode character generated by the specified key and meta
     * key state combination.
     * <p>
     * Returns the Unicode character that the specified key would produce
     * when the specified meta bits (see {@link MetaKeyKeyListener})
     * were active.
     * </p><p>
     * Returns 0 if the key is not one that is used to type Unicode
     * characters.
     * </p><p>
     * If the return value has bit {@link KeyCharacterMap#COMBINING_ACCENT} set, the
     * key is a "dead key" that should be combined with another to
     * actually produce a character -- see {@link KeyCharacterMap#getDeadChar} --
     * after masking with {@link KeyCharacterMap#COMBINING_ACCENT_MASK}.
     * </p>
     *
     * @return The associated character or combining accent, or 0 if none.
     */
    public int getUnicodeChar() {
        return getUnicodeChar(mMetaState);
    }
    
    /**
     * Gets the Unicode character generated by the specified key and meta
     * key state combination.
     * <p>
     * Returns the Unicode character that the specified key would produce
     * when the specified meta bits (see {@link MetaKeyKeyListener})
     * were active.
     * </p><p>
     * Returns 0 if the key is not one that is used to type Unicode
     * characters.
     * </p><p>
     * If the return value has bit {@link KeyCharacterMap#COMBINING_ACCENT} set, the
     * key is a "dead key" that should be combined with another to
     * actually produce a character -- see {@link KeyCharacterMap#getDeadChar} --
     * after masking with {@link KeyCharacterMap#COMBINING_ACCENT_MASK}.
     * </p>
     *
     * @param metaState The meta key modifier state.
     * @return The associated character or combining accent, or 0 if none.
     */
    public int getUnicodeChar(int metaState) {
        return getKeyCharacterMap().get(mKeyCode, metaState);
    }
    
    /**
     * Get the character conversion data for a given key code.
     *
     * @param results A {@link KeyCharacterMap.KeyData} instance that will be
     * filled with the results.
     * @return True if the key was mapped.  If the key was not mapped, results is not modified.
     *
     * @deprecated instead use {@link #getDisplayLabel()},
     * {@link #getNumber()} or {@link #getUnicodeChar(int)}.
     */
    @Deprecated
    public boolean getKeyData(KeyData results) {
        return getKeyCharacterMap().getKeyData(mKeyCode, results);
    }
    
    /**
     * Gets the first character in the character array that can be generated
     * by the specified key code.
     * <p>
     * This is a convenience function that returns the same value as
     * {@link #getMatch(char[],int) getMatch(chars, 0)}.
     * </p>
     *
     * @param chars The array of matching characters to consider.
     * @return The matching associated character, or 0 if none.
     */
    public char getMatch(char[] chars) {
        return getMatch(chars, 0);
    }
    
    /**
     * Gets the first character in the character array that can be generated
     * by the specified key code.  If there are multiple choices, prefers
     * the one that would be generated with the specified meta key modifier state.
     *
     * @param chars The array of matching characters to consider.
     * @param metaState The preferred meta key modifier state.
     * @return The matching associated character, or 0 if none.
     */
    public char getMatch(char[] chars, int metaState) {
        return getKeyCharacterMap().getMatch(mKeyCode, chars, metaState);
    }
    
    /**
     * Gets the number or symbol associated with the key.
     * <p>
     * The character value is returned, not the numeric value.
     * If the key is not a number, but is a symbol, the symbol is retuned.
     * </p><p>
     * This method is intended to to support dial pads and other numeric or
     * symbolic entry on keyboards where certain keys serve dual function
     * as alphabetic and symbolic keys.  This method returns the number
     * or symbol associated with the key independent of whether the user
     * has pressed the required modifier.
     * </p><p>
     * For example, on one particular keyboard the keys on the top QWERTY row generate
     * numbers when ALT is pressed such that ALT-Q maps to '1'.  So for that keyboard
     * when {@link #getNumber} is called with {@link KeyEvent#KEYCODE_Q} it returns '1'
     * so that the user can type numbers without pressing ALT when it makes sense.
     * </p>
     *
     * @return The associated numeric or symbolic character, or 0 if none.
     */
    public char getNumber() {
        return getKeyCharacterMap().getNumber(mKeyCode);
    }
    
    /**
     * Returns true if this key produces a glyph.
     *
     * @return True if the key is a printing key.
     */
    public boolean isPrintingKey() {
        return getKeyCharacterMap().isPrintingKey(mKeyCode);
    }
    
    /**
     * @deprecated Use {@link #dispatch(Callback, DispatcherState, Object)} instead.
     */
    @Deprecated
    public final boolean dispatch(Callback receiver) {
        return dispatch(receiver, null, null);
    }
    
    /**
     * Deliver this key event to a {@link Callback} interface.  If this is
     * an ACTION_MULTIPLE event and it is not handled, then an attempt will
     * be made to deliver a single normal event.
     * 
     * @param receiver The Callback that will be given the event.
     * @param state State information retained across events.
     * @param target The target of the dispatch, for use in tracking.
     * 
     * @return The return value from the Callback method that was called.
     */
    public final boolean dispatch(Callback receiver, DispatcherState state,
            Object target) {
        switch (mAction) {
            case ACTION_DOWN: {
                mFlags &= ~FLAG_START_TRACKING;
                if (DEBUG) Log.v(TAG, "Key down to " + target + " in " + state
                        + ": " + this);
                boolean res = receiver.onKeyDown(mKeyCode, this);
                if (state != null) {
                    if (res && mRepeatCount == 0 && (mFlags&FLAG_START_TRACKING) != 0) {
                        if (DEBUG) Log.v(TAG, "  Start tracking!");
                        state.startTracking(this, target);
                    } else if (isLongPress() && state.isTracking(this)) {
                        try {
                            if (receiver.onKeyLongPress(mKeyCode, this)) {
                                if (DEBUG) Log.v(TAG, "  Clear from long press!");
                                state.performedLongPress(this);
                                res = true;
                            }
                        } catch (AbstractMethodError e) {
                        }
                    }
                }
                return res;
            }
            case ACTION_UP:
                if (DEBUG) Log.v(TAG, "Key up to " + target + " in " + state
                        + ": " + this);
                if (state != null) {
                    state.handleUpEvent(this);
                }
                return receiver.onKeyUp(mKeyCode, this);
            case ACTION_MULTIPLE:
                final int count = mRepeatCount;
                final int code = mKeyCode;
                if (receiver.onKeyMultiple(code, count, this)) {
                    return true;
                }
                if (code != KeyEvent.KEYCODE_UNKNOWN) {
                    mAction = ACTION_DOWN;
                    mRepeatCount = 0;
                    boolean handled = receiver.onKeyDown(code, this);
                    if (handled) {
                        mAction = ACTION_UP;
                        receiver.onKeyUp(code, this);
                    }
                    mAction = ACTION_MULTIPLE;
                    mRepeatCount = count;
                    return handled;
                }
                return false;
        }
        return false;
    }

    /**
     * Use with {@link KeyEvent#dispatch(Callback, DispatcherState, Object)}
     * for more advanced key dispatching, such as long presses.
     */
    public static class DispatcherState {
        int mDownKeyCode;
        Object mDownTarget;
        SparseIntArray mActiveLongPresses = new SparseIntArray();
        
        /**
         * Reset back to initial state.
         */
        public void reset() {
            if (DEBUG) Log.v(TAG, "Reset: " + this);
            mDownKeyCode = 0;
            mDownTarget = null;
            mActiveLongPresses.clear();
        }
        
        /**
         * Stop any tracking associated with this target.
         */
        public void reset(Object target) {
            if (mDownTarget == target) {
                if (DEBUG) Log.v(TAG, "Reset in " + target + ": " + this);
                mDownKeyCode = 0;
                mDownTarget = null;
            }
        }
        
        /**
         * Start tracking the key code associated with the given event.  This
         * can only be called on a key down.  It will allow you to see any
         * long press associated with the key, and will result in
         * {@link KeyEvent#isTracking} return true on the long press and up
         * events.
         * 
         * <p>This is only needed if you are directly dispatching events, rather
         * than handling them in {@link Callback#onKeyDown}.
         */
        public void startTracking(KeyEvent event, Object target) {
            if (event.getAction() != ACTION_DOWN) {
                throw new IllegalArgumentException(
                        "Can only start tracking on a down event");
            }
            if (DEBUG) Log.v(TAG, "Start trackingt in " + target + ": " + this);
            mDownKeyCode = event.getKeyCode();
            mDownTarget = target;
        }
        
        /**
         * Return true if the key event is for a key code that is currently
         * being tracked by the dispatcher.
         */
        public boolean isTracking(KeyEvent event) {
            return mDownKeyCode == event.getKeyCode();
        }
        
        /**
         * Keep track of the given event's key code as having performed an
         * action with a long press, so no action should occur on the up.
         * <p>This is only needed if you are directly dispatching events, rather
         * than handling them in {@link Callback#onKeyLongPress}.
         */
        public void performedLongPress(KeyEvent event) {
            mActiveLongPresses.put(event.getKeyCode(), 1);
        }
        
        /**
         * Handle key up event to stop tracking.  This resets the dispatcher state,
         * and updates the key event state based on it.
         * <p>This is only needed if you are directly dispatching events, rather
         * than handling them in {@link Callback#onKeyUp}.
         */
        public void handleUpEvent(KeyEvent event) {
            final int keyCode = event.getKeyCode();
            if (DEBUG) Log.v(TAG, "Handle key up " + event + ": " + this);
            int index = mActiveLongPresses.indexOfKey(keyCode);
            if (index >= 0) {
                if (DEBUG) Log.v(TAG, "  Index: " + index);
                event.mFlags |= FLAG_CANCELED | FLAG_CANCELED_LONG_PRESS;
                mActiveLongPresses.removeAt(index);
            }
            if (mDownKeyCode == keyCode) {
                if (DEBUG) Log.v(TAG, "  Tracking!");
                event.mFlags |= FLAG_TRACKING;
                mDownKeyCode = 0;
                mDownTarget = null;
            }
        }
    }

    @Override
    public String toString() {
        return "KeyEvent{action=" + actionToString(mAction)
                + " keycode=" + keyCodeToString(mKeyCode)
                + " scancode=" + mScanCode
                + " metaState=" + metaStateToString(mMetaState)
                + " flags=0x" + Integer.toHexString(mFlags)
                + " repeat=" + mRepeatCount
                + " device=" + mDeviceId
                + " source=0x" + Integer.toHexString(mSource)
                + "}";
    }

    /**
     * Returns a string that represents the symbolic name of the specified action
     * such as "ACTION_DOWN", or "35" (if unknown).
     *
     * @param action The action.
     * @return The symbolic name of the specified action.
     * @hide
     */
    public static String actionToString(int action) {
        switch (action) {
            case ACTION_DOWN:
                return "ACTION_DOWN";
            case ACTION_UP:
                return "ACTION_UP";
            case ACTION_MULTIPLE:
                return "ACTION_MULTIPLE";
            default:
                return Integer.toString(action);
        }
    }

    /**
     * Returns a string that represents the symbolic name of the specified keycode
     * such as "KEYCODE_A", "KEYCODE_DPAD_UP", or "1001" (if unknown).
     *
     * @param keyCode The key code.
     * @return The symbolic name of the specified keycode.
     *
     * @see KeyCharacterMap#getDisplayLabel
     * @hide
     */
    public static String keyCodeToString(int keyCode) {
        if (keyCode >= 0 && keyCode < KEYCODE_SYMBOLIC_NAMES.length) {
            return KEYCODE_SYMBOLIC_NAMES[keyCode];
        }
        return Integer.toString(keyCode);
    }

    /**
     * Gets a keycode by its symbolic name such as "KEYCODE_A" or "1001" (if unknown).
     *
     * @param symbolicName The symbolic name of the keycode.
     * @return The keycode or -1 if not found.
     * @see #keycodeToString
     * @hide
     */
    public static int keyCodeFromString(String symbolicName) {
        if (symbolicName == null) {
            throw new IllegalArgumentException("symbolicName must not be null");
        }

        final int count = KEYCODE_SYMBOLIC_NAMES.length;
        for (int i = 0; i < count; i++) {
            if (symbolicName.equals(KEYCODE_SYMBOLIC_NAMES[i])) {
                return i;
            }
        }

        try {
            return Integer.parseInt(symbolicName,10);
        } catch (NumberFormatException ex) {
            return -1;
        }
    }

    /**
     * Returns a string that represents the symbolic name of the specified combined meta
     * key modifier state flags such as "0", "META_SHIFT_ON",
     * "META_ALT_ON|META_SHIFT_ON" or "0x10000000" (if unknown).
     *
     * @param metaState The meta state.
     * @return The symbolic name of the specified combined meta state flags.
     * @hide
     */
    public static String metaStateToString(int metaState) {
        if (metaState == 0) {
            return "0";
        }
        StringBuilder result = null;
        int i = 0;
        while (metaState != 0) {
            final boolean isSet = (metaState & 1) != 0;
            metaState >>>= 1; // unsigned shift!
            if (isSet) {
                final String name = META_SYMBOLIC_NAMES[i];
                if (result == null) {
                    if (metaState == 0) {
                        return name;
                    }
                    result = new StringBuilder(name);
                } else {
                    result.append('|');
                    result.append(name);
                }
            }
            i += 1;
        }
        return result.toString();
    }

    public static final Parcelable.Creator<KeyEvent> CREATOR
            = new Parcelable.Creator<KeyEvent>() {
        public KeyEvent createFromParcel(Parcel in) {
            in.readInt(); // skip token, we already know this is a KeyEvent
            return KeyEvent.createFromParcelBody(in);
        }

        public KeyEvent[] newArray(int size) {
            return new KeyEvent[size];
        }
    };
    
    /** @hide */
    public static KeyEvent createFromParcelBody(Parcel in) {
        return new KeyEvent(in);
    }
    
    private KeyEvent(Parcel in) {
        readBaseFromParcel(in);
        
        mAction = in.readInt();
        mKeyCode = in.readInt();
        mRepeatCount = in.readInt();
        mMetaState = in.readInt();
        mScanCode = in.readInt();
        mFlags = in.readInt();
        mDownTime = in.readLong();
        mEventTime = in.readLong();
    }

    public void writeToParcel(Parcel out, int flags) {
        out.writeInt(PARCEL_TOKEN_KEY_EVENT);
        
        writeBaseToParcel(out);
        
        out.writeInt(mAction);
        out.writeInt(mKeyCode);
        out.writeInt(mRepeatCount);
        out.writeInt(mMetaState);
        out.writeInt(mScanCode);
        out.writeInt(mFlags);
        out.writeLong(mDownTime);
        out.writeLong(mEventTime);
    }

    private native boolean native_isSystemKey(int keyCode);
    private native boolean native_hasDefaultAction(int keyCode);
}