EventDispatcher Interface in AS3

Cody Snider — Sat, 06 Dec 2008 19:17:02 +0000

When you’re faced with the task of firing events from within a class and you can’t extend EventDispatcher, you need to implement the IEventDispatcher interface. It’s a straightforward approach to keeping your classes loosely coupled, well-encapsulated and capable of firing their own events:

View Code ACTIONSCRIPT

class YourClass implements IEventDispatcher {
 
   private var eventDispatcher:EventDispatcher = new EventDispatcher();
 
   public function YourClass() {
      // do constructor stuff here
   }
 
   public function addEventListener(type:String, listener:Function, useCapture:Boolean=false, priority:int=0, useWeakReference:Boolean=false):void {
	eventDispatcher.addEventListener(type, listener, useCapture, priority, useWeakReference);
   }
 
   public function removeEventListener(type:String, listener:Function, useCapture:Boolean=false):void {
	eventDispatcher.removeEventListener(type, listener, useCapture);
   }
 
   public function dispatchEvent(event:Event):Boolean {
	return eventDispatcher.dispatchEvent(event);
   }
 
   public function hasEventListener(type:String):Boolean {
	return eventDispatcher.hasEventListener(type);
   }
 
   public function willTrigger(type:String):Boolean {
	return eventDispatcher.willTrigger(type);
   }
}

All we’re really doing here is creating a private EventDispatcher object and hooking all its methods through public methods of your custom class.

Coding With Cody » custom events

EventDispatcher Interface in AS3