event listener

gistfile1.coffee

	on: (event, callback) ->
		unless event? and callback? then throw Error 'on() event and callback required'
		unless @listener?
			@listener = {}
		unless @listener[event]?
			@listener[event] = []
		if -1 == @listener[event].indexOf(callback)
			@listener[event].push(callback)
	off: (event, callback) ->
		if event? and callback?
			if @listener[event]?
				index = @listener[event].indexOf(callback)
				if index != -1
					@listener[event].splice(index, 1)
		else if event?
			delete @listener[event]
		else if callback?
			for event of @listener
				index = @listener[event].indexOf(callback)
				if index != -1
					@listener[event].splice(index, 1)
		else
			delete @listener
	trigger: (event, args...) ->
		if @listener?[event]?
			for callback in @listener[event]
				setTimeout (-> callback(args)), 0