mass Framework event模块 v9

本次升级借鉴了jQuery事件模块的许多代码，可谓是jQuery事件模块的改良版。

与原先一样，拆分为两块，event模块是支持新一代的浏览器的，如IE9，chrome5+, opera10+,safari5+；event_fix是对付IE678。

拆分后的好处，在标准浏览器中，我们就不要加载这么多代码，跑这么多注定要跳过的分支，有效地提升性能。

拆分后就有利于我对标准浏览器有一个新的了解，发现firefox成为最拖后腿的一位。它在滚轮事件，focusin, focusout的迟迟不合作，让我们不得不奠出eventSupport等利器。webkit系还需要模拟mouseenter, mouseleave事件。由于标准浏览器的原生属性不能被覆盖，比如我们用mouseover来冒充mouseenter，那么我们还得将它外包一层，这工作为$.Event来做。它本来就是用于摒蔽事件对象在各浏览器的差异性的，让IE也拥有W3C的调用接口。因此$.Event还是不能移到event_fix模块。

在jQuery中还有一个simulate方法，用于让事件对象伪装成另一类事件，根据最后一个参数在本层或整个DOM树中传播。但通过研读源码发现，它的最后参数总是true，并且它也多用于修复IE的事件派发，只有一处是用于FF。因此我把它放到event_fix中去了。

在$.event.fix方法中，我发现jQuery对原事件对象的属性复制是限死的，规定好了某些属性要被复制，因此伪事件对象在一些场合还是要访问originalEvent来干活。这里我做了一些改良。并且针对鼠标事件与键盘事件这两类事件的大补丁，我也分配好它们的归属。一个目标，减少无效的分支判定。jQuery在dispatch这个方法中实在做了许多判定了，因此跑得很慢，这会在一些持续触发的事件，如scroll, resize, mousemove等非常吃力。

即使在event模块中，事件系统还是要对一些事件进行特殊处理，分别是load, focus, blur, click, beforeunload。

再来看event_fix，只要是处理IE的事件代理，change与submit，还有就是事件对象对标准的跟随。这补丁模块总归要入土的，但现在它对大陆人来说还是必不可少。

事件模块是使用wrap方式进行，完全伪装原短对象在DOM的触发行为。许多神一样的代码是jQuery团队写的，偶只是照搬。另一些奇技淫巧虽然是我自创的，但给出足够的链接希望你们能看得懂。这一个框架最重要也是最复杂的一部分，许多框架的事件系统能搞成这样具够扩展性也极让人困惑。

event.js

//=========================================
// 事件系统 v9
//==========================================
define("event", top.dispatchEvent ? ["$node"] : ["$event_fix"], function($) {
    var facade = $.event || ($.event = {
        //对某种事件类型进行特殊处理
        special: {},
        //对Mouse事件这一大类事件类型的事件对象进行特殊处理
        fixMouse: function(event, real) {
            if(event.type === "mousewheel") { //处理滚轮事件
                if("wheelDelta" in real) { //统一为±120，其中正数表示为向上滚动，负数表示向下滚动
                    // http://www.w3help.org/zh-cn/causes/SD9015
                    var delta = real.wheelDelta
                    //opera 9x系列的滚动方向与IE保持一致，10后修正
                    if(window.opera && opera.version() < 10) delta = -delta;
                    event.wheelDelta = Math.round(delta); //修正safari的浮点 bug
                } else if("detail" in real) {
                    event.wheelDelta = -real.detail * 40; //修正FF的detail 为更大众化的wheelDelta
                }
            }
        }
    }),
        eventHooks = facade.special,
        rfocusMorph = /^(?:focusinfocus|focusoutblur)$/,
        rtypenamespace = /^([^.]*)(?:\.(.+)|)$/,
        mouseEvents = "contextmenu,click,dblclick,mouseout,mouseover,mouseenter,mouseleave,mousemove,mousedown,mouseup,mousewheel,",
        eventMap = $.oneObject(mouseEvents, "Mouse"),
        types = mouseEvents + ",keypress,keydown,keyup," + "blur,focus,focusin,focusout," + "abort,error,load,unload,resize,scroll,change,input,select,reset,submit" //input
        $.eventSupport = function(eventName, el) {
            el = el || document.createElement("div");
            eventName = "on" + eventName;
            var ret = eventName in el;
            if(el.setAttribute && !ret) {
                el.setAttribute(eventName, "");
                ret = typeof el[eventName] === "function";
                el.removeAttribute(eventName);
            }
            el = null;
            return ret;
        };

    function Event(src, props) {
        if(!(this instanceof $.Event)) {
            return new Event(src, props);
        }
        this.originalEvent = {}; //保存原生事件对象
        if(src && src.type) {
            this.originalEvent = src; //重写
            this.type = src.type;
        } else {
            this.type = src;
        }
        this.defaultPrevented = false;
        if(props) {
            $.mix(this, props);
        }
        this.timeStamp = new Date - 0;
    };
    Event.prototype = {
        toString: function() {
            return "[object Event]"
        },
        preventDefault: function() { //阻止默认行为
            this.defaultPrevented = true;
            var e = this.originalEvent
            if(e && e.preventDefault) {
                e.preventDefault();
            }
            e.returnValue = false;
            return this;
        },
        stopPropagation: function() { //阻止事件在DOM树中的传播
            var e = this.originalEvent
            if(e && e.stopPropagation) {
                e.stopPropagation();
            } //propagationStopped的命名出自 http://opera.im/kb/userjs/
            e.cancelBubble = this.propagationStopped = true;
            return this;
        },
        stopImmediatePropagation: function() { //阻止事件在一个元素的同种事件的回调中传播
            this.isImmediatePropagationStopped = true;
            this.stopPropagation();
            return this;
        }
    }
    $.Event = Event;
    $.mix(eventHooks, {
        load: { //此事件不能冒泡
            noBubble: true
        },
        click: { //处理checkbox中的点击事件
            trigger: function() {
                if(this.nodeName == "INPUT" && this.type === "checkbox" && this.click) {
                    this.click();
                    return false;
                }
            }
        },
        focus: { //IE9-在不能聚焦到隐藏元素上,强制触发此事件会抛错
            trigger: function() {
                if(this !== document.activeElement && this.focus) {

                    try {
                        this.focus();
                        return false;
                    } catch(e) {}
                }
            },
            delegateType: "focusin"
        },
        blur: {
            trigger: function() { //blur事件的派发使用原生方法实现
                if(this === document.activeElement && this.blur) {
                    this.blur();
                    return false;
                }
            },
            delegateType: "focusout"
        },
        beforeunload: {
            postDispatch: function(event) {
                if(event.result !== void 0) {
                    event.originalEvent.returnValue = event.result;
                }
            }
        }
    });

    $.mix(facade, {
        //addEventListner API的支持情况:chrome 1+ FF1.6+ IE9+ opera 7+ safari 1+;
        //http://functionsource.com/post/addeventlistener-all-the-way-back-to-ie-6
        add: function(elem, hash) {
            var elemData = $._data(elem),
                //取得对应的缓存体
                types = hash.type,
                //原有的事件类型,可能是复数个
                selector = hash.selector,
                //是否使用事件代理
                handler = hash.handler; //回调函数
            if(elem.nodeType === 3 || elem.nodeType === 8 || !types || !handler) {
                return;
            }
            hash.uniqueNumber = $.getUid(handler); //确保hash.uuid与fn.uuid一致
            var events = elemData.events || (elemData.events = []),
                eventHandle = elemData.handle;
            if(!eventHandle) {
                elemData.handle = eventHandle = function(e) {
                    return typeof $ !== "undefined" && (!e || facade.triggered !== e.type) ? facade.dispatch.apply(eventHandle.elem, arguments) : void 0;
                };
                eventHandle.elem = elem; //由于IE的attachEvent回调中的this不指向绑定元素，需要强制缓存它
            }

            types.replace($.rword, function(t) {
                var tns = rtypenamespace.exec(t) || [],
                    type = tns[1];
                var namespaces = (tns[2] || "").split(".").sort();
                // 看需不需要特殊处理
                var hook = eventHooks[type] || {};
                // 事件代理与事件绑定可以使用不同的冒充事件
                type = (selector ? hook.delegateType : hook.bindType) || type;
                hook = eventHooks[type] || {};
                var handleObj = $.mix({}, hash, {
                    type: type,
                    origType: tns[1],
                    namespace: namespaces.join(".")
                });

                var handlers = events[type]; //初始化事件列队
                if(!handlers) {
                    handlers = events[type] = [];
                    handlers.delegateCount = 0;
                    if(!hook.setup || hook.setup.call(elem, namespaces, eventHandle) === false) {
                        if($["@bind"] in elem) {
                            $.bind(elem, type, eventHandle)
                        }
                    }
                }
                if(hook.add) {
                    hook.add.call(elem, handleObj);
                }
                //先处理用事件代理的回调，再处理用普通方式绑定的回调
                if(selector) {
                    handlers.splice(handlers.delegateCount++, 0, handleObj);
                } else {
                    handlers.push(handleObj);
                }
                //用于优化fire方法
                facade.global[type] = true;
            })
            //防止IE内在泄漏
            elem = null;
        },
        //用于优化事件派发
        global: {},
        //移除目标元素绑定的回调
        remove: function(elem, hash) {
            var elemData = $._data(elem),
                events, origType
            if(!(events = elemData.events)) return;

            var types = hash.type || "",
                selector = hash.selector,
                handler = hash.handler;
            types.replace($.rword, function(t) {
                var tns = rtypenamespace.exec(t) || [],
                    type = origType = tns[1],
                    namespaces = tns[2];
                //只传入命名空间,不传入事件类型,则尝试遍历所有事件类型
                if(!type) {
                    for(type in events) {
                        facade.unbind(elem, $.mix({}, hash, {
                            type: type + t
                        }));
                    }
                    return
                }
                var hook = eventHooks[type] || {};
                type = (selector ? hook.delegateType : hook.bindType) || type;
                var handlers = events[type] || [];
                var origCount = handlers.length;
                namespaces = namespaces ? new RegExp("(^|\\.)" + namespaces.split(".").sort().join("\\.(?:.*\\.|)") + "(\\.|$)") : null;

                for(var j = 0, handleObj; j < handlers.length; j++) {
                    handleObj = handlers[j];
                    //如果事件类型相同，回调相同，命名空间相同，选择器相同则移除此handleObj
                    if((origType === handleObj.origType) && (!handler || handler.uniqueNumber === handleObj.uniqueNumber) && (!namespaces || namespaces.test(handleObj.namespace)) && (!selector || selector === handleObj.selector || selector === "**" && handleObj.selector)) {
                        handlers.splice(j--, 1);

                        if(handleObj.selector) {
                            handlers.delegateCount--;
                        }
                        if(hook.remove) {
                            hook.remove.call(elem, handleObj);
                        }
                    }
                }

                if(handlers.length === 0 && origCount !== handlers.length) {
                    if(!hook.teardown || hook.teardown.call(elem, namespaces, elemData.handle) === false) {
                        if($["@bind"] in elem) {
                            $.unbind(elem, type, elemData.handle)
                        }
                    }

                    delete events[type];
                }
            })

            if($.isEmptyObject(events)) {
                delete elemData.handle;
                $._removeData(elem, "events"); //这里会尝试移除缓存体
            }
        },
        //通过传入事件类型或事件对象,触发事件回调,在整个DOM树中执行
        trigger: function(event) {
            var elem = this;
            //跳过文本节点与注释节点，主要是照顾旧式IE
            if(elem && (elem.nodeType === 3 || elem.nodeType === 8)) {
                return;
            }

            var i, cur, old, ontype, handle, eventPath, bubbleType, type = event.type || event,
                namespaces = event.namespace ? event.namespace.split(".") : [];

            // focus/blur morphs to focusin/out; ensure we're not firing them right now
            if(rfocusMorph.test(type + facade.triggered)) {
                return;
            }

            if(type.indexOf(".") >= 0) {
                //分解出命名空间
                namespaces = type.split(".");
                type = namespaces.shift();
                namespaces.sort();
            }
            //如果从来没有绑定过此种事件，也不用继续执行了
            if(!elem && !facade.global[type]) {
                return;
            }

            // Caller can pass in an Event, Object, or just an event type string
            event = typeof event === "object" ?
            // 如果是$.Event实例
            event.originalEvent ? event :
            // Object literal
            new $.Event(type, event) :
            // Just the event type (string)
            new $.Event(type);

            event.type = type;
            event.isTrigger = true;
            event.namespace = namespaces.join(".");
            event.namespace_re = event.namespace ? new RegExp("(^|\\.)" + namespaces.join("\\.(?:.*\\.|)") + "(\\.|$)") : null;
            ontype = type.indexOf(":") < 0 ? "on" + type : "";
            //清除result，方便重用
            event.result = void 0;
            if(!event.target) {
                event.target = elem;
            }
            //取得额外的参数
            var data = $.slice(arguments);
            data[0] = event;
            //判定是否需要用到事件冒充
            var hook = eventHooks[type] || {};
            if(hook.trigger && hook.trigger.apply(elem, data) === false) {
                return;
            }

            //铺设往上冒泡的路径，每小段都包括处理对象与事件类型
            eventPath = [
                [elem, hook.bindType || type]
            ];
            if(!hook.noBubble && !$.type(elem, "Window")) {

                bubbleType = hook.delegateType || type;
                cur = rfocusMorph.test(bubbleType + type) ? elem : elem.parentNode;
                for(old = elem; cur; cur = cur.parentNode) {
                    eventPath.push([cur, bubbleType]);
                    old = cur;
                }
                //一直冒泡到window
                if(old === (elem.ownerDocument || document)) {
                    eventPath.push([old.defaultView || old.parentWindow || window, bubbleType]);
                }
            }

            //沿着之前铺好的路触发事件
            for(i = 0; i < eventPath.length && !event.propagationStopped; i++) {

                cur = eventPath[i][0];
                event.type = eventPath[i][1];

                handle = ($._data(cur, "events") || {})[event.type] && $._data(cur, "handle");
                if(handle) {
                    handle.apply(cur, data);
                }
                //处理直接写在标签中的内联事件或DOM0事件
                handle = ontype && cur[ontype];
                if(handle && handle.apply && handle.apply(cur, data) === false) {
                    event.preventDefault();
                }
            }
            event.type = type;
            //如果没有阻止默认行为
            if(!event.defaultPrevented) {

                if((!hook._default || hook._default.apply(elem.ownerDocument, data) === false) && !(type === "click" && elem.nodeName == "A")) {
                    if(ontype && $.isFunction(elem[type]) && elem.nodeType) {

                        old = elem[ontype];

                        if(old) {
                            elem[ontype] = null;
                        }
                        //防止二次trigger，elem.click会再次触发addEventListener中绑定的事件
                        facade.triggered = type;
                        try {
                            //IE6-8在触发隐藏元素的focus/blur事件时会抛出异常
                            elem[type]();
                        } catch(e) {}
                        delete facade.triggered;

                        if(old) {
                            elem[ontype] = old;
                        }
                    }
                }
            }

            return event.result;
        },
        //执行用户回调,只在当前元素中执行
        dispatch: function(e) {
            //如果不存在事件回调就没有必要继续进行下去
            var eventType = e.type,
                handlers = (($._data(this, "events") || {})[eventType] || [])
                if(!handlers.length) {
                    return;
                }
                //摒蔽事件对象在各浏览器下的差异性
            var event = $.event.fix(e),
                delegateCount = handlers.delegateCount,
                args = $.slice(arguments),
                hook = eventHooks[eventType] || {},
                handlerQueue = [],
                ret, selMatch, matched, matches, handleObj, sel
                //重置第一个参数
                args[0] = event;
            event.delegateTarget = this;

            // 经典的AOP模式
            if(hook.preDispatch && hook.preDispatch.call(this, event) === false) {
                return;
            }
            //收集阶段
            //如果使用了事件代理，则先执行事件代理的回调, FF的右键会触发点击事件，与标签不符
            if(delegateCount && !(event.button && eventType === "click")) {
                for(var cur = event.target; cur != this; cur = cur.parentNode || this) {
                    //disabled元素不能触发点击事件
                    if(cur.disabled !== true || eventType !== "click") {
                        selMatch = {};
                        matches = [];
                        for(var i = 0; i < delegateCount; i++) {
                            handleObj = handlers[i];
                            sel = handleObj.selector;
                            //判定目标元素(this)的孩子(cur)是否匹配（sel）
                            if(selMatch[sel] === void 0) {
                                selMatch[sel] = $(sel, this).index(cur) >= 0
                            }
                            if(selMatch[sel]) {
                                matches.push(handleObj);
                            }
                        }
                        if(matches.length) {
                            handlerQueue.push({
                                elem: cur,
                                matches: matches
                            });
                        }
                    }
                }
            }

            // 这是事件绑定的回调
            if(handlers.length > delegateCount) {
                handlerQueue.push({
                    elem: this,
                    matches: handlers.slice(delegateCount)
                });
            }

            // 如果没有阻止事件传播，则执行它们
            for(i = 0; i < handlerQueue.length && !event.propagationStopped; i++) {
                matched = handlerQueue[i];
                event.currentTarget = matched.elem;
                for(var j = 0; j < matched.matches.length && !event.isImmediatePropagationStopped; j++) {
                    handleObj = matched.matches[j];
                    //namespace，.namespace_re属性只出现在trigger方法中
                    if(!event.namespace || event.namespace_re && event.namespace_re.test(handleObj.namespace)) {

                        event.data = handleObj.data;
                        event.handleObj = handleObj;
                        ret = ((eventHooks[handleObj.origType] || {}).handle || handleObj.handler).apply(matched.elem, args);
                        handleObj.times--;
                        if(handleObj.times === 0) { //如果有次数限制并到用光所有次数，则移除它
                            facade.unbind(matched.elem, handleObj)
                        }
                        if(ret !== void 0) {
                            event.result = ret;
                            if(ret === false) {
                                event.preventDefault();
                                event.stopPropagation();
                            }
                        }
                    }
                }
            }

            if(hook.postDispatch) {
                hook.postDispatch.call(this, event);
            }

            return event.result;
        },

        //修正事件对象,摒蔽差异性
        fix: function(event) {
            if(!event.originalEvent) {
                var real = event;
                event = $.Event(real);
                //复制真实事件对象的成员
                for(var p in real) {
                    if(!(p in event)) {
                        event[p] = real[p]
                    }
                }
                //如果不存在target属性，为它添加一个
                if(!event.target) {
                    event.target = event.srcElement || document;
                }
                //safari的事件源对象可能为文本节点，应代入其父节点
                if(event.target.nodeType === 3) {
                    event.target = event.target.parentNode;
                }
                event.metaKey = !! event.ctrlKey; // 处理IE678的组合键
                var callback = facade["fix" + eventMap[event.type]]
                if(typeof callback == "function") {
                    callback(event, real)
                }
            }
            return event;
        }
    });
    facade.bind = facade.add;
    facade.unbind = facade.remove;
    //以下是用户使用的API
    $.implement({
        hover: function(fnIn, fnOut) {
            return this.mouseenter(fnIn).mouseleave(fnOut || fnIn);
        },
        delegate: function(selector, types, fn, times) {
            return this.on(types, selector, fn, times);
        },
        live: function(types, fn, times) {
            $.log("$.fn.live() is deprecated")
            $(this.ownerDocument).on(types, this.selector, fn, times);
            return this;
        },
        one: function(types, fn) {
            return this.on(types, fn, 1);
        },
        undelegate: function(selector, types, fn) { /*顺序不能乱*/
            return arguments.length == 1 ? this.off(selector, "**") : this.off(types, fn, selector);
        },
        die: function(types, fn) {
            $.log("$.fn.die() is deprecated")
            $(this.ownerDocument).off(types, fn, this.selector || "**", fn);
            return this;
        },
        fire: function() {
            var args = arguments;
            return this.each(function() {
                facade.trigger.apply(this, args);
            });
        }
    });
    //这个迭代器产生四个重要的事件绑定API on off bind unbind
    var rtypes = /^[a-z0-9_\-\.\s\,]+$/i
    "on_bind,off_unbind".replace($.rmapper, function(_, method, mapper) {
        $.fn[method] = function(types, selector, fn) {
            if(typeof types === "object") {
                for(var type in types) {
                    $.fn[method](this, type, selector, types[type], fn);
                }
                return this;
            }
            var hash = {};
            for(var i = 0; i < arguments.length; i++) {
                var el = arguments[i];
                if(typeof el == "number") {
                    hash.times = el;
                } else if(typeof el == "function") {
                    hash.handler = el
                }
                if(typeof el === "string") {
                    if(hash.type != null) {
                        hash.selector = el.trim();
                    } else {
                        hash.type = el.trim(); //只能为字母数字-_.空格
                        if(!rtypes.test(hash.type)) {
                            throw new Error("事件类型格式不正确")
                        }
                    }
                }
            }
            if(!hash.type) {
                throw new Error("必须指明事件类型")
            }
            if(method === "on" && !hash.handler) {
                throw new Error("必须指明事件回调")
            }
            hash.times = hash.times > 0 ? hash.times : Infinity;
            return this.each(function() {
                facade[mapper](this, hash);
            });
        }
        $.fn[mapper] = function() { // $.fn.bind $.fn.unbind
            return $.fn[method].apply(this, arguments);
        }
    });

    types.replace($.rword, function(type) { //这里产生以事件名命名的快捷方法
        eventMap[type] = eventMap[type] || (/key/.test(type) ? "Keyboard" : "HTML")
        $.fn[type] = function(callback) {
            return callback ? this.bind(type, callback) : this.fire(type);
        }
    });
    /* mouseenter/mouseleave/focusin/focusout已为标准事件，经测试IE5+，opera11,FF10+都支持它们
详见http://www.filehippo.com/pl/download_opera/changelog/9476/
         */
    if(!+"\v1" || !$.eventSupport("mouseenter")) { //IE6789不能实现捕获与safari chrome不支持
        "mouseenter_mouseover,mouseleave_mouseout".replace($.rmapper, function(_, type, fix) {
            eventHooks[type] = {
                delegateType: fix,
                bindType: fix,
                handle: function(event) {
                    var ret, target = this,
                        related = event.relatedTarget,
                        handleObj = event.handleObj;
                    // For mousenter/leave call the handler if related is outside the target.
                    // NB: No relatedTarget if the mouse left/entered the browser window
                    if(!related || (related !== target && !$.contains(target, related))) {
                        event.type = handleObj.origType;
                        ret = handleObj.handler.apply(this, arguments);
                        event.type = fix;
                    }
                    return ret;
                }
            }
        });
    }
    //现在只有firefox不支持focusin,focusout事件,并且它也不支持DOMFocusIn,DOMFocusOut,不能像DOMMouseScroll那样简单冒充,Firefox 17+
    if(!$.support.focusin) {
        "focusin_focus,focusout_blur".replace($.rmapper, function(_, orig, fix) {
            var attaches = 0,
                handler = function(event) {
                    event = facade.fix(event);
                    $.mix(event, {
                        type: orig,
                        isSimulated: true
                    });
                    facade.trigger.call(event.target, event);
                };
            eventHooks[orig] = {
                setup: function() {
                    if(attaches++ === 0) {
                        document.addEventListener(fix, handler, true);
                    }
                },
                teardown: function() {
                    if(--attaches === 0) {
                        document.removeEventListener(fix, handler, true);
                    }
                }
            };
        });
    }
    try {
        //FF需要用DOMMouseScroll事件模拟mousewheel事件
        document.createEvent("MouseScrollEvents");
        eventHooks.mousewheel = {
            bindType: "DOMMouseScroll",
            delegateType: "DOMMouseScroll"
        }
        if($.eventSupport("mousewheel")) {
            delete eventHooks.mousewheel;
        }
    } catch(e) {};

    return $;
})

event_fix.js

define("event_fix", !! document.dispatchEvent, ["$node"], function($) {
    //模拟IE678的reset,submit,change的事件代理
    var rformElems = /^(?:input|select|textarea)$/i
    var facade = $.event = {
        special: {},
        fixMouse: function(event) {
            // 处理鼠标事件 http://www.w3help.org/zh-cn/causes/BX9008
            var doc = event.target.ownerDocument || document; //safari与chrome下，滚动条，视窗相关的东西是放在body上
            var box = document.compatMode == "BackCompat" ? doc.body : doc.documentElement
            event.pageX = event.clientX + (box.scrollLeft >> 0) - (box.clientLeft >> 0);
            event.pageY = event.clientY + (box.scrollTop >> 0) - (box.clientTop >> 0);
            //如果不存在relatedTarget属性，为它添加一个
            if(!event.relatedTarget && event.fromElement) { //mouseover mouseout
                event.relatedTarget = event.fromElement === event.target ? event.toElement : event.fromElement;
            }
            //标准浏览判定按下鼠标哪个键，左1中2右3
            var button = event.button
            //IE event.button的意义 0：没有键被按下 1：按下左键 2：按下右键 3：左键与右键同时被按下 4：按下中键 5：左键与中键同时被按下 6：中键与右键同时被按下 7：三个键同时被按下
            event.which = [0, 1, 3, 0, 2, 0, 0, 0][button]; //0现在代表没有意义
        },
        fixKeyboard: function(event) {
            event.which = event.charCode != null ? event.charCode : event.keyCode;
        }
    };
    var special = facade.special

    function simulate(type, elem, event) {
        event = new $.Event(event);
        $.mix({
            type: type,
            isSimulated: true
        });
        $.event.trigger.call(elem, event);
        if(event.defaultPrevented) {
            event.preventDefault();
        }
    }
    special.change = {
        setup: function() {
            if(rformElems.test(this.nodeName)) {
                // IE doesn't fire change on a check/radio until blur; trigger it on click
                // after a propertychange. Eat the blur-change in special.change.handle.
                // This still fires onchange a second time for check/radio after blur.
                if(this.type === "checkbox" || this.type === "radio") {
                    $(this).bind("propertychange._change", function(event) {
                        if(event.originalEvent.propertyName === "checked") {
                            this._just_changed = true;
                        }
                    });
                    $(this).bind("click._change", function(event) {
                        if(this._just_changed && !event.isTrigger) {
                            this._just_changed = false;
                        }
                        // Allow triggered, simulated change events (#11500)
                        simulate("change", this, event);
                    });
                }
                return false;
            }
            // Delegated event; lazy-add a change handler on descendant inputs
            $(this).bind("beforeactivate._change", function(e) {
                var elem = e.target;
                if(rformElems.test(elem.nodeName) && !$._data(elem, "_change_attached")) {
                    $(elem).bind("change._change", function(event) {
                        if(this.parentNode && !event.isSimulated && !event.isTrigger) {
                            simulate("change", this.parentNode, event);
                        }
                        $._data(elem, "_change_attached", true);
                    })
                }
            });
        },
        handle: function(event) {
            var elem = event.target;
            // Swallow native change events from checkbox/radio, we already triggered them above
            if(this !== elem || event.isSimulated || event.isTrigger || (elem.type !== "radio" && elem.type !== "checkbox")) {
                return event.handleObj.handler.apply(this, arguments);
            }
        },
        teardown: function() {
            facade.remove(this, "._change");
            return !rformElems.test(this.nodeName);
        }
    }
    special.submit = {
        setup: function() {
            // Only need this for delegated form submit events
            if(this.tagName === "FORM") {
                return false;
            }
            // Lazy-add a submit handler when a descendant form may potentially be submitted
            $(this).bind("click._submit keypress._submit", function(e) {
                // Node name check avoids a VML-related crash in IE (#9807)
                var elem = e.target,
                form = /input|button/i.test(elem.tagName) ? elem.form : undefined;
                if(form && !$._data(form, "_submit_attached")) {
                    facade.bind(form, {
                        type: "submit._submit",
                        callback: function(event) {
                            event._submit_bubble = true;
                        }
                    });
                    $._data(form, "_submit_attached", true);
                }
            });
        // return undefined since we don't need an event listener
        },

        postDispatch: function(event) {
            // If form was submitted by the user, bubble the event up the tree
            if(event._submit_bubble) {
                delete event._submit_bubble;
                if(this.parentNode && !event.isTrigger) {
                    simulate("submit", this.parentNode, event);
                }
            }
        },

        teardown: function() {
            if(this.tagName == "FORM") {
                return false;
            }
            facade.remove(this, "._submit");
        }
    }
    return $;
})