event.js

这是YUI的源码及相关示例。里面有很多很炫的Javascript效果。

            /**
             * Removes a blur event listener
             *
             * @method removeBlurListener
             *
             * @param {String|HTMLElement|Array|NodeList} el An id, an element 
             *  reference, or a collection of ids and/or elements to remove
             *  the listener from.
             * @param {Function} fn the method the event invokes.  If fn is
             *  undefined, then all event handlers for the type of event are 
             *  removed.
             * @return {boolean} true if the unbind was successful, false 
             *  otherwise.
             * @static
             */
            removeBlurListener: function (el, fn) { 
            
                return this._removeListener(el, _BLUR, fn, true);
            
            },

            /**
             * When using legacy events, the handler is routed to this object
             * so we can fire our custom listener stack.
             * @method fireLegacyEvent
             * @static
             * @private
             */
            fireLegacyEvent: function(e, legacyIndex) {
                var ok=true, le, lh, li, scope, ret;
                
                lh = legacyHandlers[legacyIndex].slice();
                for (var i=0, len=lh.length; i<len; ++i) {
                // for (var i in lh.length) {
                    li = lh[i];
                    if ( li && li[this.WFN] ) {
                        scope = li[this.ADJ_SCOPE];
                        ret = li[this.WFN].call(scope, e);
                        ok = (ok && ret);
                    }
                }

                // Fire the original handler if we replaced one.  We fire this
                // after the other events to keep stopPropagation/preventDefault
                // that happened in the DOM0 handler from touching our DOM2
                // substitute
                le = legacyEvents[legacyIndex];
                if (le && le[2]) {
                    le[2](e);
                }
                
                return ok;
            },

            /**
             * Returns the legacy event index that matches the supplied 
             * signature
             * @method getLegacyIndex
             * @static
             * @private
             */
            getLegacyIndex: function(el, sType) {
                var key = this.generateId(el) + sType;
                if (typeof legacyMap[key] == "undefined") { 
                    return -1;
                } else {
                    return legacyMap[key];
                }
            },

            /**
             * Logic that determines when we should automatically use legacy
             * events instead of DOM2 events.  Currently this is limited to old
             * Safari browsers with a broken preventDefault
             * @method useLegacyEvent
             * @static
             * @private
             */
            useLegacyEvent: function(el, sType) {
return (this.webkit && this.webkit < 419 && ("click"==sType || "dblclick"==sType));
            },
                    
            /**
             * Removes an event listener
             *
             * @method _removeListener
             *
             * @param {String|HTMLElement|Array|NodeList} el An id, an element 
             *  reference, or a collection of ids and/or elements to remove
             *  the listener from.
             * @param {String} sType the type of event to remove.
             * @param {Function} fn the method the event invokes.  If fn is
             *  undefined, then all event handlers for the type of event are 
             *  removed.
             * @param {boolen}      capture capture or bubble phase             
             * @return {boolean} true if the unbind was successful, false 
             *  otherwise.
             * @static
             * @private
             */
            _removeListener: function(el, sType, fn, capture) {
                var i, len, li;

                // The el argument can be a string
                if (typeof el == "string") {
                    el = this.getEl(el);
                // The el argument can be an array of elements or element ids.
                } else if ( this._isValidCollection(el)) {
                    var ok = true;
                    for (i=el.length-1; i>-1; i--) {
                        ok = ( this._removeListener(el[i], sType, fn, capture) && ok );
                    }
                    return ok;
                }

                if (!fn || !fn.call) {
                    //return false;
                    return this.purgeElement(el, false, sType);
                }

                if ("unload" == sType) {

                    for (i=unloadListeners.length-1; i>-1; i--) {
                        li = unloadListeners[i];
                        if (li && 
                            li[0] == el && 
                            li[1] == sType && 
                            li[2] == fn) {
                                unloadListeners.splice(i, 1);
                                // unloadListeners[i]=null;
                                return true;
                        }
                    }

                    return false;
                }

                var cacheItem = null;

                // The index is a hidden parameter; needed to remove it from
                // the method signature because it was tempting users to
                // try and take advantage of it, which is not possible.
                var index = arguments[4];
  
                if ("undefined" === typeof index) {
                    index = this._getCacheIndex(el, sType, fn);
                }

                if (index >= 0) {
                    cacheItem = listeners[index];
                }

                if (!el || !cacheItem) {
                    return false;
                }


                if (this.useLegacyEvent(el, sType)) {
                    var legacyIndex = this.getLegacyIndex(el, sType);
                    var llist = legacyHandlers[legacyIndex];
                    if (llist) {
                        for (i=0, len=llist.length; i<len; ++i) {
                        // for (i in llist.length) {
                            li = llist[i];
                            if (li && 
                                li[this.EL] == el && 
                                li[this.TYPE] == sType && 
                                li[this.FN] == fn) {
                                    llist.splice(i, 1);
                                    // llist[i]=null;
                                    break;
                            }
                        }
                    }

                } else {
                    try {
                        this._simpleRemove(el, sType, cacheItem[this.WFN], capture);
                    } catch(ex) {
                        this.lastError = ex;
                        return false;
                    }
                }

                // removed the wrapped handler
                delete listeners[index][this.WFN];
                delete listeners[index][this.FN];
                listeners.splice(index, 1);
                // listeners[index]=null;

                return true;

            },


            /**
             * Removes an event listener
             *
             * @method removeListener
             *
             * @param {String|HTMLElement|Array|NodeList} el An id, an element 
             *  reference, or a collection of ids and/or elements to remove
             *  the listener from.
             * @param {String} sType the type of event to remove.
             * @param {Function} fn the method the event invokes.  If fn is
             *  undefined, then all event handlers for the type of event are 
             *  removed.
             * @return {boolean} true if the unbind was successful, false 
             *  otherwise.
             * @static
             */
            removeListener: function(el, sType, fn) {

				return this._removeListener(el, sType, fn, false);

            },


            /**
             * Returns the event's target element.  Safari sometimes provides
             * a text node, and this is automatically resolved to the text
             * node's parent so that it behaves like other browsers.
             * @method getTarget
             * @param {Event} ev the event
             * @param {boolean} resolveTextNode when set to true the target's
             *                  parent will be returned if the target is a 
             *                  text node.  @deprecated, the text node is
             *                  now resolved automatically
             * @return {HTMLElement} the event's target
             * @static
             */
            getTarget: function(ev, resolveTextNode) {
                var t = ev.target || ev.srcElement;
                return this.resolveTextNode(t);
            },

            /**
             * In some cases, some browsers will return a text node inside
             * the actual element that was targeted.  This normalizes the
             * return value for getTarget and getRelatedTarget.
             * @method resolveTextNode
             * @param {HTMLElement} node node to resolve
             * @return {HTMLElement} the normized node
             * @static
             */
            resolveTextNode: function(n) {
                try {
                    if (n && 3 == n.nodeType) {
                        return n.parentNode;
                    }
                } catch(e) { }

                return n;
            },

            /**
             * Returns the event's pageX
             * @method getPageX
             * @param {Event} ev the event
             * @return {int} the event's pageX
             * @static
             */
            getPageX: function(ev) {
                var x = ev.pageX;
                if (!x && 0 !== x) {
                    x = ev.clientX || 0;

                    if ( this.isIE ) {
                        x += this._getScrollLeft();
                    }
                }

                return x;
            },

            /**
             * Returns the event's pageY
             * @method getPageY
             * @param {Event} ev the event
             * @return {int} the event's pageY
             * @static
             */
            getPageY: function(ev) {
                var y = ev.pageY;
                if (!y && 0 !== y) {
                    y = ev.clientY || 0;

                    if ( this.isIE ) {
                        y += this._getScrollTop();
                    }
                }


                return y;
            },

            /**
             * Returns the pageX and pageY properties as an indexed array.
             * @method getXY
             * @param {Event} ev the event
             * @return {[x, y]} the pageX and pageY properties of the event
             * @static
             */
            getXY: function(ev) {
                return [this.getPageX(ev), this.getPageY(ev)];
            },

            /**
             * Returns the event's related target 
             * @method getRelatedTarget
             * @param {Event} ev the event
             * @return {HTMLElement} the event's relatedTarget
             * @static
             */
            getRelatedTarget: function(ev) {
                var t = ev.relatedTarget;
                if (!t) {
                    if (ev.type == "mouseout") {
                        t = ev.toElement;
                    } else if (ev.type == "mouseover") {
                        t = ev.fromElement;
                    }
                }

                return this.resolveTextNode(t);
            },

            /**
             * Returns the time of the event.  If the time is not included, the
             * event is modified using the current time.
             * @method getTime
             * @param {Event} ev the event
             * @return {Date} the time of the event
             * @static
             */
            getTime: function(ev) {
                if (!ev.time) {
                    var t = new Date().getTime();
                    try {
                        ev.time = t;
                    } catch(ex) { 
                        this.lastError = ex;
                        return t;
                    }
                }

                return ev.time;
            },

            /**
             * Convenience method for stopPropagation + preventDefault
             * @method stopEvent
             * @param {Event} ev the event
             * @static
             */
            stopEvent: function(ev) {
                this.stopPropagation(ev);
                this.preventDefault(ev);
            },

            /**
             * Stops event propagation
             * @method stopPropagation
             * @param {Event} ev the event
             * @static
             */