// Copyright 2006 Google Inc.
// All Rights Reserved
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 
//  * Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in
//    the documentation and/or other materials provided with the
//    distribution.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE. 

/*
 * @fileoverview Constant declarations for common key codes.
 *
 */

goog.provide('goog.events.KeyCodes');

goog.require('goog.events');


/**
 * Key codes for common characters.
 *
 * This list is not localized and therefor some of the key codes are not correct
 * for non US keyboard layouts. See comments below.
 *
 * @enum {number}
 */
goog.events.KeyCodes = {
  MAC_ENTER: 3,
  BACKSPACE: 8,
  TAB: 9,
  NUM_CENTER: 12,
  ENTER: 13,
  SHIFT: 16,
  CTRL: 17,
  ALT: 18,
  PAUSE: 19,
  CAPS_LOCK: 20,
  ESC: 27,
  SPACE: 32,
  PAGE_UP: 33,     // also NUM_NORTH_EAST
  PAGE_DOWN: 34,   // also NUM_SOUTH_EAST
  END: 35,         // also NUM_SOUTH_WEST
  HOME: 36,        // also NUM_NORTH_WEST
  LEFT: 37,        // also NUM_WEST
  UP: 38,          // also NUM_NORTH
  RIGHT: 39,       // also NUM_EAST
  DOWN: 40,        // also NUM_SOUTH
  PRINT_SCREEN: 44,
  INSERT: 45,      // also NUM_INSERT
  DELETE: 46,      // also NUM_DELETE
  ZERO: 48,
  ONE: 49,
  TWO: 50,
  THREE: 51,
  FOUR: 52,
  FIVE: 53,
  SIX: 54,
  SEVEN: 55,
  EIGHT: 56,
  NINE: 57,
  QUESTION_MARK: 63, // needs localization
  A: 65,
  B: 66,
  C: 67,
  D: 68,
  E: 69,
  F: 70,
  G: 71,
  H: 72,
  I: 73,
  J: 74,
  K: 75,
  L: 76,
  M: 77,
  N: 78,
  O: 79,
  P: 80,
  Q: 81,
  R: 82,
  S: 83,
  T: 84,
  U: 85,
  V: 86,
  W: 87,
  X: 88,
  Y: 89,
  Z: 90,
  META: 91,
  CONTEXT_MENU: 93,
  NUM_ZERO: 96,
  NUM_ONE: 97,
  NUM_TWO: 98,
  NUM_THREE: 99,
  NUM_FOUR: 100,
  NUM_FIVE: 101,
  NUM_SIX: 102,
  NUM_SEVEN: 103,
  NUM_EIGHT: 104,
  NUM_NINE: 105,
  NUM_MULTIPLY: 106,
  NUM_PLUS: 107,
  NUM_MINUS: 109,
  NUM_PERIOD: 110,
  NUM_DIVISION: 111,
  F1: 112,
  F2: 113,
  F3: 114,
  F4: 115,
  F5: 116,
  F6: 117,
  F7: 118,
  F8: 119,
  F9: 120,
  F10: 121,
  F11: 122,
  F12: 123,
  NUMLOCK: 144,
  SEMICOLON: 186,            // needs localization
  DASH: 189,                 // needs localization
  EQUALS: 187,               // needs localization
  COMMA: 188,                // needs localization
  PERIOD: 190,               // needs localization
  SLASH: 191,                // needs localization
  APOSTROPHE: 192,           // needs localization
  SINGLE_QUOTE: 222,         // needs localization
  OPEN_SQUARE_BRACKET: 219,  // needs localization
  BACKSLASH: 220,            // needs localization
  CLOSE_SQUARE_BRACKET: 221, // needs localization
  WIN_KEY: 224,
  MAC_FF_META: 224, // Firefox (Gecko) fires this for the meta key instead of 91
  WIN_IME: 229
};


/**
 * Returns true if the event contains a text modifying key
 * @param {goog.events.BrowserEvent} e A key event.
 * @return {boolean} Whether it's a text modifying key.
 */
goog.events.KeyCodes.isTextModifyingKeyEvent = function(e) {
  if (e.altKey && !e.ctrlKey ||
      e.metaKey ||
      // Function keys don't generate text
      e.keyCode >= goog.events.KeyCodes.F1 &&
      e.keyCode <= goog.events.KeyCodes.F12) {
    return false;
  }

  // The following keys are quite harmless, even in combination with
  // CTRL, ALT or SHIFT.
  switch (e.keyCode) {
    case goog.events.KeyCodes.ALT:
    case goog.events.KeyCodes.SHIFT:
    case goog.events.KeyCodes.CTRL:
    case goog.events.KeyCodes.PAUSE:
    case goog.events.KeyCodes.CAPS_LOCK:
    case goog.events.KeyCodes.ESC:
    case goog.events.KeyCodes.PAGE_UP:
    case goog.events.KeyCodes.PAGE_DOWN:
    case goog.events.KeyCodes.HOME:
    case goog.events.KeyCodes.END:
    case goog.events.KeyCodes.LEFT:
    case goog.events.KeyCodes.RIGHT:
    case goog.events.KeyCodes.UP:
    case goog.events.KeyCodes.DOWN:
    case goog.events.KeyCodes.INSERT:
    case goog.events.KeyCodes.NUMLOCK:
    case goog.events.KeyCodes.CONTEXT_MENU:
    case goog.events.KeyCodes.PRINT_SCREEN:
      return false;
    default:
      return true;
  }
};


/**
 * Returns true if the key fires a keypress event in the current browser.
 *
 * Accoridng to MSDN [1] IE only fires keypress events for the following keys:
 * - Letters: A - Z (uppercase and lowercase)
 * - Numerals: 0 - 9
 * - Symbols: ! @ # $ % ^ & * ( ) _ - + = < [ ] { } , . / ? \ | ' ` " ~
 * - System: ESC, SPACEBAR, ENTER
 *
 * That's not entirely correct though, for instance there's no distinction
 * between upper and lower case letters.
 *
 * [1] http://msdn2.microsoft.com/en-us/library/ms536939(VS.85).aspx)
 *
 * Safari is similar to IE, but does not fire keypress for ESC.
 *
 * Additionally, IE6 does not fire keydown or keypress events for letters when
 * the control or alt keys are held down and the shift key is not. IE7 does
 * fire keydown in these cases, though, but not keypress.
 *
 * @param {number} keyCode A key code.
 * @param {number} opt_heldKeyCode Key code of a currently-held key.
 * @param {boolean} opt_shiftKey Whether the shift key is held down.
 * @return {boolean} Whether it's a key that fires a keypress event.
 */
goog.events.KeyCodes.firesKeyPressEvent = function(keyCode, opt_heldKeyCode,
    opt_shiftKey) {
  if (!goog.userAgent.IE &&
      !(goog.userAgent.WEBKIT && goog.userAgent.isVersion('525'))) {
    return true;
  }

  // Saves Ctrl or Alt + key for IE7, which won't fire keypress.
  if (goog.userAgent.IE &&
      !opt_shiftKey &&
      (opt_heldKeyCode == goog.events.KeyCodes.CTRL ||
       opt_heldKeyCode == goog.events.KeyCodes.ALT)) {
    return false;
  }

  if (keyCode >= goog.events.KeyCodes.ZERO &&
      keyCode <= goog.events.KeyCodes.NINE) {
    return true;
  }

  if (keyCode >= goog.events.KeyCodes.NUM_ZERO &&
      keyCode <= goog.events.KeyCodes.NUM_MULTIPLY) {
    return true;
  }

  if (keyCode >= goog.events.KeyCodes.A &&
      keyCode <= goog.events.KeyCodes.Z) {
    return true;
  }

  if (keyCode == goog.events.KeyCodes.ESC &&
      goog.userAgent.WEBKIT) {
    return false;
  }

  switch (keyCode) {
    case goog.events.KeyCodes.ENTER:
    case goog.events.KeyCodes.ESC:
    case goog.events.KeyCodes.SPACE:
    case goog.events.KeyCodes.QUESTION_MARK:
    case goog.events.KeyCodes.NUM_PLUS:
    case goog.events.KeyCodes.NUM_MINUS:
    case goog.events.KeyCodes.NUM_PERIOD:
    case goog.events.KeyCodes.NUM_DIVISION:
    case goog.events.KeyCodes.SEMICOLON:
    case goog.events.KeyCodes.DASH:
    case goog.events.KeyCodes.EQUALS:
    case goog.events.KeyCodes.COMMA:
    case goog.events.KeyCodes.PERIOD:
    case goog.events.KeyCodes.SLASH:
    case goog.events.KeyCodes.APOSTROPHE:
    case goog.events.KeyCodes.SINGLE_QUOTE:
    case goog.events.KeyCodes.OPEN_SQUARE_BRACKET:
    case goog.events.KeyCodes.BACKSLASH:
    case goog.events.KeyCodes.CLOSE_SQUARE_BRACKET:
      return true;
    default:
      return false;
  }
};


/**
 * Returns true if the key produces a character.
 *
 * @param {number} keyCode A key code.
 * @return {boolean} Whether it's a character key.
 */
goog.events.KeyCodes.isCharacterKey = function(keyCode) {
  if (keyCode >= goog.events.KeyCodes.ZERO &&
      keyCode <= goog.events.KeyCodes.NINE) {
    return true;
  }

  if (keyCode >= goog.events.KeyCodes.NUM_ZERO &&
      keyCode <= goog.events.KeyCodes.NUM_MULTIPLY) {
    return true;
  }

  if (keyCode >= goog.events.KeyCodes.A &&
      keyCode <= goog.events.KeyCodes.Z) {
    return true;
  }

  switch (keyCode) {
    case goog.events.KeyCodes.SPACE:
    case goog.events.KeyCodes.QUESTION_MARK:
    case goog.events.KeyCodes.NUM_PLUS:
    case goog.events.KeyCodes.NUM_MINUS:
    case goog.events.KeyCodes.NUM_PERIOD:
    case goog.events.KeyCodes.NUM_DIVISION:
    case goog.events.KeyCodes.SEMICOLON:
    case goog.events.KeyCodes.DASH:
    case goog.events.KeyCodes.EQUALS:
    case goog.events.KeyCodes.COMMA:
    case goog.events.KeyCodes.PERIOD:
    case goog.events.KeyCodes.SLASH:
    case goog.events.KeyCodes.APOSTROPHE:
    case goog.events.KeyCodes.SINGLE_QUOTE:
    case goog.events.KeyCodes.OPEN_SQUARE_BRACKET:
    case goog.events.KeyCodes.BACKSLASH:
    case goog.events.KeyCodes.CLOSE_SQUARE_BRACKET:
      return true;
    default:
      return false;
  }
};