flex eventBus

package com.wks.util
{
?import flash.events.Event;
?import flash.events.EventDispatcher;

?public class EventBus extends EventDispatcher ?{ ??public function EventBus() ??{ ??} ??private static var manager:EventBus; ?? ??public static const CHANGEVIEW:String = "changeViewStackIndex"; ?? ??public static function getInstance():EventBus ??{ ???if(!manager)manager = new EventBus; ???return manager; ??} ??public function dispatch(type:String):Boolean ??{ ???return dispatchEvent(new Event(type)); ??} ?} }