jQuery的事件模型

(function(s){
        var addEvent = (function(){
            if(window.addEventListener){
                return function (el,type,fn) {
                    el.addEventListener(type,fn,false);
                }
            }else{
                return function(el,type,fn){
                    el.attachEvent(‘on‘+type,fn);
                }
            }
        })();
        var removeEvent = (function (){
            if(window.removeEventListener){
                return function(el,type,fn){
                    el.removeEventListener(type,fn,false);
                }
            }else{
                return function(el,type,fn){
                    el.detachEvent(‘on‘+type,fn);
                }
            }
        })();

        // HandlerObject constructor
        function Handler(config){
            this.handler = config.handler;
            this.special = config.special; //特殊的回调，ex. once函数，throggle函数等等，原回调放在此处，handler放包裹后的回调
            this.type = config.type;
            this.namespace = config.namespace;
            this.data = config.data;
            this.once = config.once;
            this.delay = config.delay;
            this.throttle = config.throttle;
            this.stop = config.stop;  //  取消默认和冒泡
            this.stopBubble = config.stopBubble;
            this.preventDefalut = config.preventDefalut;
        }
        //typeEvents=[handlerObj1,handlerObj2,...]
        function execHandlers(el,event,args,context){  // 若args不为空，则为自定义事件出发，trigger
            if(el.nodeValue == 3 || el.nodeValue == 8) return;
            var elData,events,handlers,typeEvents,ret,
                flag = true;
            context = context || el;
            //获取缓存对象
            elData= S._data(el);
            if(!elData || !elData[‘events‘])return;
            events = elData[‘events‘];
            handlers = elData[‘handlers‘];
            if(!events[event.type])return;
            typeEvents = events[event.type];

            for(var i= 0,len=typeEvents.length;i<len;i++){
                ret = execHandler(el,event,typeEvents[i],args,context);
                if(ret == false){
                    flag = false
                }
            }
            if(!flag){
                event.preventDefalut();
                event.stopPropagation();
            }
            return;
        }
        function execHandler(el,event,handlerObj,args,context){
            var handler = handlerObj.handler,
                type = event.type,
                special = handlerObj.special,
                stop = handlerObj.stop,
                preventDefault = handlerObj.preventDefalut,
                stopBubble = handlerObj.stopBubble,
                data = handlerObj.data,
                once = handlerObj.once,
                delay = handlerObj.delay,  // 时延
                throttle = handlerObj.throttle; //最小间隔时间
            if(handlerObj.type && type !== handlerObj.type) return;

            if(!handler || !S.isFunction(handler))return;

            if(stop){
                event.preventDefalut();
                event.stopPropagation();
            }
            if(preventDefault){
                event.preventDefalut();
            }
            if(stopBubble){
                event.stopPropagation();
            }


            if(once){
                var onceHandler = function(event,args){
                    return S.once(handler,context,event,args);
                };
                return onceHandler.call(context,event,args);
            }
            if(delay && S.isNumber(delay)){
                var delayHandler = function(event,args){
                    return S.delay(handler,context,delay,event,args);
                }
                return delayHandler.call(context,event,args);
            }
            if(throttle && S.isNumber(throttle)){
                var throttleHandler = function(event,args){
                    return S.throttle(handler,context,throttle,event,args);
                }
                return throttleHandler.call(context,event,args);
            }

            if(handler){
                return handler.call(context,event,args);
            }
            return;
        }

        function returnTrue(){
            return true;
        }
        function returnFalse(){
            return false;
        }
        //Event constructor
        function Event(e){ //传入事件参数
            this.originalEvent = e;
            var type = e.type;
            if(/^(\w+)\.(\w+)$/.test(type)){
                this.type = RegExp.$1;
                this.namespace = RegExp.$2
            }else{
                this.type = type;
                this.namespace = ‘‘;
            }
        }

        Event.prototype = {
            preventDefault: function(){
                var e = this.originalEvent;
                if(e.preventDefalut){
                    return e.preventDefault();
                }
                e.returnValue = false;
                this.isPreventDefault = returnTrue;
                return;
            },
            stopPropagation: function(){
                var e = this.originalEvent;
                if(e.stopPropagation){
                    return e.stopPropagation();
                }
                e.stopBubble = true;
                this.isStopPropagation = returnTrue;
                return;
            },
            stopImmediatePropagation: function(){
                this.stopPropagation();
                this.isImmediatePropagationStopped = returnTrue;
            },
            isPreventDefault: returnFalse,
            isStopPropagation: returnFalse
        };
        //事件修复
        function fixEvent(event){
            var i, prop, props = [], originalEvent = event.originalEvent;

            props = props.concat(‘altKey bubbles button cancelable charCode clientX clientY ctrlKey currentTarget‘.split(‘ ‘));
            props = props.concat(‘data detail eventPhase fromElement handler keyCode layerX layerY metaKey‘.split(‘ ‘));
            props = props.concat(‘newValue offsetX offsetY originalTarget pageX pageY prevValue relatedTarget‘.split(‘ ‘));
            props = props.concat(‘screenX screenY shiftKey target toElement view wheelDelta which‘.split(‘ ‘));
            for(i=props.length;--i;){
                event[props[i]] = originalEvent[props[i]];
            }

            if(!event.target){
                event.target = event.srcElement;
            }

            if(event.target.nodeType == 3){
                event.target = event.target.parentNode;
            }

            if(!event.relatedTarget){
                event.relatedTarget = event.fromElement === event.target? event.toElement : event.fromElement;
            }

            if(!event.which && (event.charCode || event.keyCode)){
                event.which = event.charCode ? event.charCode : event.keyCode ? event.keyCode : null;
            }

            if(!event.pageX || !event.pageY){
                event.pageX = event.clientX + (doc.documentElement && doc.documentElement.scrollLeft || doc.body && doc.body.scrollLeft || 0)
                - (doc.documentElement && doc.documentElement.clientLeft || doc.body && doc.body.clientLeft || 0);
                event.pageY = event.clientY + (doc.documentElement && doc.documentElement.scrollTop || doc.body && doc.body.scrollTop || 0)
                    - (doc.documentElement && doc.documentElement.clientTop || doc.body && doc.body.clientTop || 0);
            }

            if(!event.which && event.button != undefined){ //ie下 0 无动作, 1 左键 ,2 右键, 4 中间键
                event.which = (event.button & 1) ? 1 : (event.button & 2) ? 3 : (event.button & 4) ? 2 : 0;
            }
            return event;
        }

        function bind(el,type,fn){
            if(el.nodeType && el.nodeType == 3 || el.nodeType == 8) return;

            var elData= S._data(el),events,handlers,typeEvents;
            if(!elData) {
                S._lockData(el);  //开辟缓存
                elData = S._data(el);
            }
            if(!elData[‘events‘]){
                elData[‘events‘]  = {};
            }
            events = elData[‘events‘];
            handlers = elData[‘handlers‘];  // 目前先不对其赋值
            if(!events[type]){
                events[type] = [];
            }
            typeEvents = events[type];

            var handlerObj;
            if(S.isFunction(fn)){
                handlerObj = new Handler({handler: fn});
            }else if(S.isObject(fn)){
                handlerObj = new Handler(fn);
            }else{
                return;
            }

            handlerObj.handlerHook = function(event,args){  // 函数钩子，用于unbind删除回调函数
                event = event || window.event;
                var e = new Event(event);
                e = fixEvent(e);
                execHandlers(el,e,args,el);
            };

            typeEvents.push(handlerObj);

            addEvent(el,type,handlerObj.handlerHook);
        }

        function unbind(el,type,fn){
            if(el.nodeType && el.nodeType == 3 || el.nodeType == 8) return;

            var elData= S._data(el),events,handlers,typeEvents;

            if(!elData || !elData[‘events‘])return;

            if(arguments.length == 1){  // 删除该元素所有缓存 事件
                for(var i in elData[‘events‘]){
                    if(elData[‘events‘].hasOwnProperty(i)){
                        for(var j=0,len=elData[‘events‘][i].length;j<len;j++){
                            removeEvent(el,i,elData[‘events‘][i][j].handlerHook);
                        }
                    }
                }
                S._unData(el);
            }

            events = elData[‘events‘][type];
            if(arguments.length == 2 && events){
                try{
                    for(var i= 0,len=events.length;i<len;i++){
                        removeEvent(el,type,events[i].handlerHook);
                    }
                }catch(e){
                    throw new TypeError(‘哎呀啊，解除回调出现意外‘)
                }

                events = {};
                delete elData[type];
            }

            if(arguments.length == 3){
                for(var i= 0,len=events.length;i<len;i++){
                    if(events[i].handler === fn){
                        try{
                            removeEvent(el,type,events[i].handlerHook);
                        }catch(e){
                            throw new TypeError(‘哎呀啊，解除回调出现意外‘)
                        }
                        events.splice(i,1);
                    }
                }
            }
        }

        function trigger(el,type,args){
            if(el.nodeType && el.nodeType == 3 || el.nodeType == 8) return;

            var elData= S._data(el),events,handlers,typeEvents;

            if(!elData || !elData[‘events‘] || !elData[‘events‘][type])return;
            events = elData[‘events‘][type];

            var handlerObj,event;
            event = {
                target: el,
                type: type,
                data: args
            };
            for(var len=events.length;--len>=0;){
                handlerObj = events[len];
                handlerObj.handlerHook(event,args);
            }
        }

        S.fn.extend({
            bind: function(type,fn){
                this.each(function(el){
                    bind.call(el,el,type,fn);
                })

            },
            unbind: function(type,fn){
                var args = arguments;
                this.each(function(el){
                    args.length == 0 ? unbind.call(el,el) : args.length == 1 ?
                        unbind.call(el,el,type) : unbind.call(el,el,type,fn);

                })

            },
            trigger: function(type,args){
                this.each(function(el){
                    trigger.call(el,el,type,args);
                })
            }
        })
    })(Screen);