keyboard.js

Keyboard = function(){
    this.keys =  {
        'BACKSPACE': 8,
        'TAB': 9,
        'ENTER': 13,
        'PAUSE': 19,
        'CAPS': 20,
        'ESC': 27,
        'SPACE': 32,
        'PAGE_UP': 33,
        'PAGE_DOWN': 34,
        'END': 35,
        'HOME': 36,
        'LEFT_ARROW': 37,
        'UP_ARROW': 38,
        'RIGHT_ARROW': 39,
        'DOWN_ARROW': 40,
        'INSERT': 45,
        'DELETE': 46,
        '0': 48,
        '1': 49,
        '2': 50,
        '3': 51,
        '4': 52,
        '5': 53,
        '6': 54,
        '7': 55,
        '8': 56,
        '9': 57,
        '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,
        'NUMPAD_0': 96,
        'NUMPAD_1': 97,
        'NUMPAD_2': 98,
        'NUMPAD_3': 99,
        'NUMPAD_4': 100,
        'NUMPAD_5': 101,
        'NUMPAD_6': 102,
        'NUMPAD_7': 103,
        'NUMPAD_8': 104,
        'NUMPAD_9': 105,
        'MULTIPLY': 106,
        'ADD': 107,
        'SUBSTRACT': 109,
        'DECIMAL': 110,
        'DIVIDE': 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,
        'SHIFT': 16,
        'CTRL': 17,
        'ALT': 18,
        'PLUS': 187,
        'COMMA': 188,
        'MINUS': 189,
        'PERIOD': 190
    };
    this.keyDown = {};
    this.anyDown = false;
    this.countKeys = 0;
    this.active = true;
}
Keyboard.prototype.disable = function(){
    this.active = false;
}
Keyboard.prototype.enable = function(){
    this.active = true;
}
Keyboard.prototype.enabled = function(){
    return this.active;
}
Keyboard.prototype.isDown = function(key){
    if(!this.active) return false;
    if(!key) return this.anyDown;
    
    if(typeof key === "string") key = this.keys[key];  
    return !!this.keyDown[key];
}


Keyboard.prototype.dispatch = function(e){
    var code = null;
    if (!e) var e = window.event;
    if (e.keyCode) code = e.keyCode;
    else if (e.which) code = e.which;
    else if (e.code) code = e.code;
    
    if(e.type === "keydown"){
        if(!this.keyDown[code]){
            this.keyDown[code] = true;
            this.countKeys++;
        }
    }
    if(e.type === "keyup"){
       
        if(this.keyDown[code]){
            delete this.keyDown[code];
            this.countKeys--;
        }
 
    }
    if(this.countKeys > 0){
        this.anyDown = true;
    }else{
        this.anyDown = false;
    }
}
Keyboard.prototype.preventDefault = function(e){
    if (!e) var e = window.event;
    e.cancelBubble = true;
    if (e.stopPropagation) e.stopPropagation();
}