Example file of a an event connection system

on_example.js

(function(b){
// NOTE: "b" is the main library, "bv" (BetterVideo)

	var cons = {}, aListeners = {};
	var fns = [];
	var theOne;
	var topics = {};
	var d_topics = {};
	var DEFAULT_TIMER = 30;
	var WKADJUST = (b.is_chrome && b.is_chrome()) ? -20 : -120; // don't break if sniff.js is not incl

	var tch = 'ontouchstart' in window.document;

	var eventMap = {
		'click': tch ? 'touchend' : 'click',
		'mouseup': tch ? 'touchend' : 'mouseup',
		'mousedown': tch ? 'touchstart' : 'mousedown',
		'mousemove': tch ? 'touchmove' : 'mousemove'
	};


	var normalize = function(evt){
		evt.explicitOriginalTarget = evt.currentTarget = evt.toElement;
		evt.target = evt.srcElement;
		return evt;
	}

	var standardsScroll = function(evt){
		//console.log("scroll", evt.wheelDelta/120, " - - ", evt.wheelDeltaX, evt.wheelDeltaY)
		var o = {
			type:"scroll"
		}
		if(evt.wheelDelta){
			//console.log("WHEELDELTA");
			// Safari
			if(evt.wheelDeltaX){
				o.horizontal = true;
				o.vertical = false;
				o.scrollX = evt.wheelDeltaX/WKADJUST;
				o.scrollY = 0;
			}else{
				o.horizontal = false;
				o.vertical = true;
				o.scrollX = 0;
				o.scrollY = evt.wheelDeltaY/WKADJUST; // Saf is backwards!
			}
		}else{
			//console.log("SCROLL");
			if(evt.axis == evt.HORIZONTAL_AXIS){
				o.horizontal = true;
				o.vertical = false;
				o.scrollX = evt.detail;
				o.scrollY = 0;
			}else{
				o.horizontal = false;
				o.vertical = true;
				o.scrollX = 0;
				o.scrollY = evt.detail;
			}
		}
		return o;
	}

	var groupHandles = {};
	var groups = {
		add: function(type, handle){
			if(!groupHandles[type]) groupHandles[type] = [];
			groupHandles[type].push(handle);
		},
		remove: function(type){
			groupHandles[type].forEach(function(handle){
				handle.remove();
			});
		},
		pause: function(type){
			groupHandles[type].forEach(function(handle){
				handle.remove();
			});
		},
		resume: function(type){
			groupHandles[type].forEach(function(handle){
				handle.remove();
			});
		}
	};


	//var log = b.log('ON', 1);

	b.mix({
		multi:{
			sub: function(obj, ctx){
				var subs = [];
				for(var nm in obj){
					subs.push(b.sub(nm, ctx, obj[nm]));
				}
				return {
					remove: function(){
						b.each(subs, function(s){ s.remove(); });
					},
					pause: function(){
						b.each(subs, function(s){ s.pause(); });
					},
					resume: function(){
						b.each(subs, function(s){ s.resume(); });
					}
				}
			},

			on: function(obj, source, ctx, type){
				var subs = [];
				ctx = ctx || null;
				for(var nm in obj){
					subs.push(b.on(source, nm, !!ctx?ctx:obj[nm], !!ctx?obj[nm]:null, type));
				}
				return {
					remove: function(){
						b.each(subs, function(s){ s.remove(); });
					},
					pause: function(){
						b.each(subs, function(s){ s.pause(); });
					},
					resume: function(){
						b.each(subs, function(s){ s.resume(); });
					}
				}
			}
		},


		sub: function(channel, ctx, method, type){

			if(!topics[channel]){
				topics[channel] = {}; d_topics[channel] = {};
			}
			var cb = this.bind(ctx, method);
			var uid = this.uid("sub");
			topics[channel][uid] = cb;
			var handle = {
				remove: function(){
					delete topics[channel][uid];
				},
				pause: function(){
					this.cb = topics[channel][uid];
					topics[channel][uid] = function(){}
				},
				resume: function(){
					if(!this.cb) return;
					topics[channel][uid] = this.cb;
				}
			};
			if(type) groups.add(handle);
			return handle;
		},

		pub: function(channel){
			//console.log('pub:', channel, topics[channel])
			if(!topics[channel]) return;
			var args = Array.prototype.slice.call(arguments);
			args.shift();
			for(var nm in topics[channel]){
				topics[channel][nm].apply(null, args);
			}
		},

		on: function(object, name, ctx, method, type){
			//if(name == "unload") return this.unload(ctx, method, type);
			//log('on', name)
			var _o = object;
			if(object === "timer" || object === "timeout" || object === "interval"){
				console.error('on.timer removed', object, name, method);
				//console.trace();
			}
			name = eventMap[name] || name;
			if(typeof(object) == "string") object = this.byId(object);
			if(!object){
				console.error("no 'on' object found:", _o, "(", "event:", name, "method:", method, ")");
				console.trace();
				return null;
			}
			if(type == "once"){
				return this.once(object, name, ctx, method);
			}

			if(typeof(name) != "string"){ // ctx is 2nd, name 3rd
				var c = ctx; ctx = name; name = c;
			}
			if(typeof(name) != "string"){ // name is an object of name/methods
				for(var nm in name){
					this.on(object, nm, ctx, name[nm]);
				}
				return 0; // no handle for this.
			}

			var fn = !!method ? this.bind(ctx, method) : ctx;
			var paused = function(){}
			var resumed = fn;
			var realFn;
			var newFn = object[name];

			if(object.addEventListener){ // Silverlight?
				//console.log("object.addEventListener:", name);

				if(name == "scroll"){
					name = b.is_ff() ? "DOMMouseScroll" : "mousewheel";
					var _fn = fn;
					fn = function(evt){
						//console.log("onscroll");
						_fn(standardsScroll(evt), evt);
					}
					// FIXME:
					// fn is used for pause, so _fn breaks it
					// maybe addEventListener should be duplicated here
				}

				if(name == "mouseenter" || name == "mouseleave"){
					name = name == "mouseenter" ? "mouseover" : "mouseout";
					realFn = function(evt){
						if(!b.isDescendant(evt.relatedTarget, object)){
							fn(evt);
						}
					}
					object.addEventListener(name, realFn, false);
				}else{
					realFn = function(evt){
						fn(evt);
					}
					object.addEventListener(name, realFn, false);
				}



			}else if(object.attachEvent){
				//console.log("object.attachEvent", name);
				if(name == "scroll") name = "mousewheel";
				var realFn = function(){
					fn(normalize(window.event));
				}
				object.attachEvent("on"+name, realFn);

			}else{ // AOP
				//console.log("object.AOP", name);
				object[name] = function(){
					// the 'before' looks backwards, but it works
					if(type!="before") newFn.apply(object, arguments);
					fn.apply(null, arguments);
					if(type=="before") newFn.apply(object, arguments);
				}
			}
			var handle = {
				remove: function(){
					fn = paused;
					// does not work with AOP: object.removeEventListener(name, realFn, false);
				},
				pause: function(){
					fn = paused;
				},
				resume: function(){
					fn = resumed;
				}
			};
			if(type) groups.add(type, handle);
			return handle;
		},

		once: function(object, name, ctx, method){
			var fn = this.bind(ctx, method);
			var handle = this.on(object, name, function(){
				handle.remove();
				fn.apply(null, arguments);
			});
		},

		press: function(node, source, method, arg){
			var fn = this.bind(source, method);
			var passArg = arg;
			var handle, offHandle, downHandle;
			var tch =  bv.supports.touch();
			var fire = function(){
				handle = setInterval(function(){
					fn(passArg);
				}, 20);
			}
			var stop = function(evt){
				offHandle.pause();
				clearInterval(handle);
			}
			downHandle = this.on(node, tch ? "touchstart" : "mousedown", function(evt){
				//console.log("PRESS");
				b.stopEvent(evt);
				offHandle.resume();
				fire();
			});
			offHandle = this.on(document, tch ? "touchend" : "mouseup", function(evt){
				//console.log("RELEASE CANCEL")
				b.stopEvent(evt);
				stop();
			});
			stop();

			return downHandle;
		},



		bind: function(ctx, func, dbg){
			// NON-DEBUG
			//if(dbg)
			//return b.bindX(ctx, func, dbg);
			if(typeof(func) == "string"){
				if(!func){ func = ctx; ctx = window; }
				return function(){
					ctx[func].apply(ctx, arguments); }
			}else{
				var method = !!func ? ctx.func || func : ctx;
				var scope = !!func ? ctx : null;
				return function(){ method.apply(scope, arguments); }
			}
		},

		partial: function(o, f){
			f = typeof(f)=="string" ? o[f] : !o.f ? this.bind(o, f) : o.f;
			return function(args){
				f.apply(o, args);
			}
		},

		mouse: function(e, noscroll){
			var posx = 0;
			var posy = 0;
			var d = document;
			if (e.pageX || e.pageY){
				posx = e.pageX;
				posy = e.pageY;
				if(noscroll){
					posx -= d.body.scrollLeft + d.documentElement.scrollLeft
					posy -= d.body.scrollTop + d.documentElement.scrollTop;
				}
				//console.info("pageY:", posy);
			}else if (e.clientX || e.clientY){
				posx = e.clientX;
				posy = e.clientY;
				//console.info("clientY:", posy);
				if(!noscroll){
					posx += d.body.scrollLeft + d.documentElement.scrollLeft
					posy += d.body.scrollTop + d.documentElement.scrollTop;
				}
			}
			return {
				x:posx,
				y:posy
			};
		},

		stopEvent: function(evt){
			evt = evt || window.event;
			if(!evt) return false;
			if(evt.preventDefault){
				evt.preventDefault();
				evt.stopPropagation();
			}else{
				evt.cancelBubble = true;
				evt.returnValue = false;
			}
			return false;
		}
	});

	b.sub.debug = function(){
		//console.dir(d_topics);
	}

	b.on.remove = groups.remove;
	b.on.pause = groups.pause;
	b.on.resume = groups.resume;

})(window.bv);