/////////////////////////////////////////////////////////////////////////////////////////////////////
//
//	Created: 		14-Oct-2008
//	Last Modified:  14-Nov-2008
//	Author:			Taka Kojima
//
/////////////////////////////////////////////////////////////////////////////////////////////////////

package ayz.managers{

	/**
	* The EventManager clas is used to propogate events across an entire application/site.
	* <p/>
	* It does not extend or append native event handling in any way, so as not to confuse the two, it is its own thing.
	* <p/>
	* The way EventManager works is quite simple actually. All it does is maintain a multidimensional array of events/components.
	*/

	import flash.utils.Dictionary;

    public class EventManager{

		public static var interestsList:Dictionary = new Dictionary(true);

		/**
		* Lets the EventManager know that this component/module is interested in these events.
		* <p/>
		* Thereafter, when EventManager.fireEvent gets called for any correlating event, it will let the component know.
		*
		* @param	component			The component that is interested in the event.
		* @param	interests			An array of interests. All events/interests are in this case are strings. Although it is very common/standard to set up an Events class with static vars for easy referenece/rememberance.
		*/

		public static function registerInterests(component:*, interests:Array):void{
			for(var i:int = 0; i < interests.length; i ++){
				if(EventManager.interestsList[interests[i]] == undefined){EventManager.interestsList[interests[i]] = new Dictionary(true);}

				if(EventManager.interestsList[interests[i]][component] == undefined){
					EventManager.interestsList[interests[i]][component] = interests[i];
				}
				else{throw new Error("Trying to add duplicate interest (" + interests[i] + ") on " + component);}
			}
		}

		/**
		* Lets the EventManager know that this component/module is no longer interested in these events.
		* <p/>
		* Thereafter, when EventManager.fireEvent gets called for any correlating event, it will no longer let the component know.
		*
		* @param	component			The component to unregister for listed events/interests.
		* @param	interests			An array of interests. All events/interests are in this case are strings. Although it is very common/standard to set up an Events class with static vars for easy referenece/rememberance.
		*/

		public static function unregisterInterests(component:*, interests:Array):void{
			for(var i:int = 0; i < interests.length; i ++){
				if(EventManager.interestsList[interests[i]] is Dictionary){
					if(EventManager.interestsList[interests[i]][component] != undefined){delete EventManager.interestsList[interests[i]][component];}
				}
			}
		}

		/**
		* Fire an event, letting all interested components know of said event.
		*
		* @param	event				The event that is being fired.
		* @param	args				An Object of arguments. It's an Object so as to be flexible/dynamic.
		*/

		public static function fireEvent(interest:String, args:Object = null):void{
			if(EventManager.interestsList[interest] is Dictionary){

				var interestedComponents:Dictionary = EventManager.interestsList[interest];

				for(var component:Object in interestedComponents){
					if(component.catchEvent != null){
						component.catchEvent(interest, args);
					}
					else{
						throw new Error("catchEvent Function not found on " + component);
					}
				}

			}
		}
	}
}