Phaser.Key = function (game, keycode){ 
this.game = game; 
this.isDown = false ; 
this.isUp = false ; 
this.altKey = false ; 
this.ctrlKey = false ; 
this.shiftKey = false ; 
this.timeDown = 0; 
this.duration = 0; 
this.timeUp = 0; 
this.repeats = 0; 
this.keyCode = keycode; 
this.onDown = new Phaser.Signal(); 
this.onUp = new Phaser.Signal(); 
} 
; 
Phaser.Key.prototype = { 
processKeyDown: function (event){ 
this.altKey = event.altKey; 
this.ctrlKey = event.ctrlKey; 
this.shiftKey = event.shiftKey; 
if (this.isDown) { 
this.duration = event.timeStamp - this.timeDown; 
this.repeats++ ; 
} 
 else { 
this.isDown = true ; 
this.isUp = false ; 
this.timeDown = event.timeStamp; 
this.duration = 0; 
this.repeats = 0; 
this.onDown.dispatch(this); 
} 
} 
,
processKeyUp: function (event){ 
this.isDown = false ; 
this.isUp = true ; 
this.timeUp = event.timeStamp; 
this.onUp.dispatch(this); 
} 
,
justPressed: function (duration){ 
if (typeof duration === "undefined") { 
duration = 250; 
} 
return (this.isDown && this.duration < duration); 
} 
,
justReleased: function (duration){ 
if (typeof duration === "undefined") { 
duration = 250; 
} 
return (this.isDown === false  && (this.game.time.now - this.timeUp < duration)); 
} 
}
;