todomvc/examples/canjs_require/bower_components/canjs/amd/can/util/event.js

> Helping you select an MV\* framework

/*!
 * CanJS - 2.0.3
 * http://canjs.us/
 * Copyright (c) 2013 Bitovi
 * Tue, 26 Nov 2013 18:21:22 GMT
 * Licensed MIT
 * Includes: CanJS default build
 * Download from: http://canjs.us/
 */
define(["can/util/can"], function(can){



	// event.js
	// ---------
	// _Basic event wrapper._
can.addEvent = function( event, fn ) {
	var allEvents = this.__bindEvents || (this.__bindEvents = {}),
		eventList = allEvents[event] || (allEvents[event] = []);

	eventList.push({
		handler: fn,
		name: event
	});
	return this;
};

// can.listenTo works without knowing how bind works
// the API was heavily influenced by BackboneJS:
// http://backbonejs.org/
can.listenTo = function(other, event, handler){


	var idedEvents = this.__listenToEvents;
	if(!idedEvents){
		idedEvents = this.__listenToEvents = {};
	}
	var otherId = can.cid(other);
	var othersEvents = idedEvents[otherId];
	if(!othersEvents){
		othersEvents = idedEvents[otherId] = {
			obj: other,
			events: {}
		};
	}
	var eventsEvents = othersEvents.events[event]
	if(!eventsEvents){
		eventsEvents = othersEvents.events[event] = []
	}
	eventsEvents.push(handler);
	can.bind.call(other, event, handler);
}

can.stopListening = function(other, event, handler){
	var idedEvents = this.__listenToEvents,
		iterIdedEvents = idedEvents,
		i = 0;
	if(!idedEvents) {
		return this;
	}
	if( other ) {
		var othercid = can.cid(other);
		(iterIdedEvents = {})[othercid] = idedEvents[othercid];
		// you might be trying to listen to something that is not there
		if(!idedEvents[othercid]){
			return this;
		}
	}


	for(var cid in iterIdedEvents) {
		var othersEvents = iterIdedEvents[cid],
			eventsEvents;
		other = idedEvents[cid].obj;
		if( ! event ) {
			eventsEvents = othersEvents.events;
		} else {
			(eventsEvents = {})[event] = othersEvents.events[event]
		}
		for(var eventName in eventsEvents) {
			var handlers = eventsEvents[eventName] || [];
			i = 0;
			while(i < handlers.length){
				if( (handler && handler === handlers[i]) || (! handler ) ) {
					can.unbind.call(other, eventName, handlers[i])
					handlers.splice(i, 1);

				} else {
					i++;
				}
			}
			// no more handlers?
			if( !handlers.length ){
				delete othersEvents.events[eventName]
			}
		}
		if( can.isEmptyObject(othersEvents.events )){
			delete idedEvents[cid]
		}
	}
	return this;
}

can.removeEvent = function(event, fn){
	if(!this.__bindEvents){
		return this;
	}

	var events = this.__bindEvents[event] || [],
		i =0,
		ev,
		isFunction = typeof fn == 'function';

	while(i < events.length){
		ev = events[i]
		if( (isFunction && ev.handler === fn) || (!isFunction && ev.cid === fn ) ) {
			events.splice(i, 1);
		} else {
			i++;
		}
	}


	return this;
};

can.dispatch = function(event, args){
	if(!this.__bindEvents){
		return;
	}
	if(typeof event == "string"){
		event = {type: event}
	}
	var eventName = event.type,
		handlers = (this.__bindEvents[eventName] || []).slice(0),
		args = [event].concat(args||[]);

	for(var i =0, len = handlers.length; i < len; i++) {
		ev = handlers[i];
		ev.handler.apply(this, args);
	};
}

return can;

});