AS3 判断双击事件

//双击事件触发的时候不触发单击事件

package {
	import com.greensock.TweenLite;
	
	import flash.display.DisplayObjectContainer;
	import flash.display.Sprite;
	import flash.events.MouseEvent;
	import flash.utils.getTimer;
	
	public class Test1 extends Sprite {
		private var _rect:Sprite;
		
		public function Test1() {
			trace("hello world");
			
			//            this.stage.addEventListener(MouseEvent.CLICK, __onTraceClick);
			
			drawRect();
			_rect.addEventListener(MouseEvent.ROLL_OVER, __onOver);
			_rect.addEventListener(MouseEvent.ROLL_OUT, __onOut);
			_rect.addEventListener(MouseEvent.MOUSE_DOWN, __onDown);
			
		}
		
		
		private function __onOver(evt:MouseEvent):void {
			//trace("over");
		}
		private function __onOut(evt:MouseEvent):void {
			//trace("out");
		}
		
		private var _preDownTime:int = 0;
		private function __onDown(evt:MouseEvent):void {
			trace("down");
			
			TweenLite.killDelayedCallsTo(doClick);
			
			_rect.addEventListener(MouseEvent.MOUSE_UP, __onUp);
			_rect.startDrag();
			
			_preDownTime = getTimer();
		}
		
		
		private const UP_INTER:int = 300;
		private var _preUpTime:int = 0;
		private function __onUp(evt:MouseEvent):void {
			trace("up");
			_rect.removeEventListener(MouseEvent.MOUSE_UP, __onUp);
			_rect.stopDrag();
			
			var now:int = getTimer();
			if((now - _preUpTime) < UP_INTER) {
				trace("----double click");
			} else if((now - _preDownTime) < UP_INTER) {
				TweenLite.delayedCall(0.2, doClick);
			} else {
				trace("drag");
			}
			_preUpTime = now;
		}
		
		private function doClick():void {
			trace("----click");
		}
		
		private function __onTraceClick(evt:MouseEvent):void {
			var str:String = "";
			trace(printTrace(evt.target as DisplayObjectContainer));
		}
		
		private function printTrace(sp:DisplayObjectContainer):String {
			if(null == sp) {
				return "";
			} else {
				
				return sp.toString() + "/" + printTrace(sp.parent);
			}
		}
		private function drawRect():void {
			var rect:Sprite = new Sprite();
			
			// red rect, starting at point 50, 50
			rect.graphics.beginFill(0xFF0000);
			rect.graphics.moveTo(50, 50);
			rect.graphics.lineTo(150,50);
			rect.graphics.lineTo(150,150);
			rect.graphics.lineTo(50,150);
			rect.graphics.endFill();
			_rect = rect;
			this.addChild(_rect);
		}
		
		
		
	}
}