Weblabor

(function ()
{
	var observableMap=new HashMap();
	Object.override(
	{
		listeners: function (event,build)
		{
			var observerMap=observableMap.get(this) || (build && observableMap.put(this,new Map()));
			if (observerMap)
			{
				var listeners=observerMap.get(event);
				if (!listeners && build)
				{
					listeners=observerMap.put(event,new HashSet());
					this.fire("eventset",event,listeners);
				}
				return listeners;
			}
		},
		on: function (event,listener)
		{
			this.listeners(event,true).add(listener);
			this.fire("eventappend",event,listener);
			return this;
		},
		un: function (event,listener)
		{
			var listeners=this.listeners(event,false);
			if (listeners)
			{
				this.fire("eventremove",event,listener);
				listeners.remove(listener);
				if (listeners.empty())
				{
					this.fire("eventdestroy",event,listeners);
					observableMap.get(this).removeKey(event);
				}
			}
			return this;
		},
		fire: function (event)
		{
			var params=arguments.callee.argumentList();
			params.shift();
			if (event!="eventfire")
			{
				this.fire("eventfire",event,params);
			}
			var listeners=this.listeners(event,false);
			if (listeners)
			{
				listeners.each(function (listener)
				{
					listener.apply(this,params);
				},this);
			}
			return this;
		}
	});
})();

function prepareCallback(func) {
    // Olyan függvényt állítunk elő amiben a this már az esemény célpontja.
    return function (event) {
      var target = normalizeEvent(event),
          returnValue = func.call(target, event);
 
      if (returnValue === false) {
        event.preventDefault();
        event.stopPropagation();
      }
 
      return returnValue;
    };
  }

func.call(target, event);