AS3 双击管理工具

package
{
	import flash.display.InteractiveObject;
	import flash.events.MouseEvent;
	import flash.utils.getTimer;
	
	/**
	 * 双击工具（不使用Flash源生的方式，源生的方式是：第二下up时才触发，而这种方式是，第二次down时就触发）
	 * http://blog.csdn.net/linjf520/article/details/9314095
	 * @author jave.lin
	 * @date 2013-7-2
	 */	
	public class DoubleClickUtil{
		
		private static const DOUBLE_CLICK_INTNERVAL:int = 500;
		
		private static var before_double_click_time:int = -1;
		private static var isDoubleClick:Boolean = false;
		private static var lastObj:InteractiveObject;
		
		public static function registerDoubleClick(obj:InteractiveObject):void{
			obj.addEventListener(MouseEvent.CLICK, onClick, false, int.MAX_VALUE);
			obj.addEventListener(MouseEvent.MOUSE_DOWN, onDown, false, int.MAX_VALUE);
			//			obj.addEventListener(MouseEvent.DOUBLE_CLICK, onDoubleClick, false, int.MAX_VALUE);
			obj.doubleClickEnabled = false;
		}
		
		public static function unRegisterDoubleClick(obj:InteractiveObject):void{
			obj.removeEventListener(MouseEvent.CLICK, onClick, false);
			obj.removeEventListener(MouseEvent.MOUSE_DOWN, onDown, false);
		}
		
		//		private static function onDoubleClick(e:MouseEvent):void{
		//			trace("onDoubleClick");
		//		}
		
		private static function onDown(e:MouseEvent):void{
			//			trace("onDown");
			var timer:int = getTimer();
			if(lastObj == e.currentTarget && before_double_click_time != -1){
				//				trace("minus:" + (timer - before_double_click_time));
				//				trace("can double?:" + ((timer - before_double_click_time)