package index.base.game{
  
  import flash.events.EventDispatcher;
  import flash.events.KeyboardEvent;
  import flash.events.Event;
  import flash.display.InteractiveObject;
  
  import index.base.events.DirectionEvent;
  
  public class Direction extends EventDispatcher{
    
    //方向表示
    public static const UP:uint = 0;
    public static const DOWN:uint = 1;
    public static const LEFT:uint = 2;
    public static const RIGHT:uint = 3;
    
    //作用区域
    public var area:InteractiveObject;
    
    //上下左右键值
    private const directionAr:Array = new Array(4);
    
    //是否上下左右
    private var _up:Boolean = false;
    private var _down:Boolean = false;
    private var _left:Boolean = false;
    private var _right:Boolean = false;
    
    public function Direction(_area:InteractiveObject,_up:uint = 38,_down:uint = 40,_left:uint = 37,_right:uint = 39){
      area = _area;
      directionAr[UP] = _up;
      directionAr[DOWN] = _down;
      directionAr[LEFT] = _left;
      directionAr[RIGHT] = _right;
      start();
    }
    
    //开始获取事件
    public function start():void{
      area.addEventListener(KeyboardEvent.KEY_DOWN,onKeyDown);
      area.addEventListener(KeyboardEvent.KEY_UP,onKeyUp);
      
      area.addEventListener(Event.ENTER_FRAME,onEnterFrame);
    }
    
    //事件帧频繁触发
    private function onEnterFrame(e:Event):void{
      var num:uint = Number(_up) + Number(_down) + Number(_left) + Number(_right);
      if(num == 0){
        return;
      }
      
      var eve:DirectionEvent = new DirectionEvent(DirectionEvent.DO);
      eve.up = _up;
      eve.down = _down;
      eve.left = _left;
      eve.right = _right;
      dispatchEvent(eve);
    }
    
    //停止获取事件
    public function stop():void{
      area.removeEventListener(KeyboardEvent.KEY_DOWN,onKeyDown);
      area.removeEventListener(KeyboardEvent.KEY_UP,onKeyUp);
    }
    
    //鼠标按下去事件
    private function onKeyDown(e:KeyboardEvent):void{
      key(e.keyCode,true)
    }
    
    //鼠标弹上来事件
    private function onKeyUp(e:KeyboardEvent):void{
      key(e.keyCode,false)
    }
    
    //变化状态
    private function key(num:uint,isDown:Boolean):void{
      switch(num){
        case directionAr[UP]:
          _up = isDown;
        break;
        case directionAr[DOWN]:
          _down = isDown;
        break;
        case directionAr[LEFT]:
          _left = isDown;
        break;
        case directionAr[RIGHT]:
          _right = isDown;
        break;
      }
    }
    
    //设置按钮
    public function setKey(num:uint,vars:uint){
      directionAr[num] = vars;
    }
  }
}