event.js

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

                        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;

            },

            /**
             * 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(node) {
                if (node && 3 == node.nodeType) {
                    return node.parentNode;
                } else {
                    return node;
                }
            },

            /**
             * 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
             */
            stopPropagation: function(ev) {
                if (ev.stopPropagation) {
                    ev.stopPropagation();
                } else {
                    ev.cancelBubble = true;
                }
            },

            /**
             * Prevents the default behavior of the event
             * @method preventDefault
             * @param {Event} ev the event
             * @static
             */
            preventDefault: function(ev) {
                if (ev.preventDefault) {
                    ev.preventDefault();
                } else {
                    ev.returnValue = false;
                }
            },
             
            /**
             * Finds the event in the window object, the caller's arguments, or
             * in the arguments of another method in the callstack.  This is
             * executed automatically for events registered through the event
             * manager, so the implementer should not normally need to execute
             * this function at all.
             * @method getEvent
             * @param {Event} e the event parameter from the handler
             * @param {HTMLElement} boundEl the element the listener is attached to
             * @return {Event} the event 
             * @static
             */
            getEvent: function(e, boundEl) {
                var ev = e || window.event;

                if (!ev) {
                    var c = this.getEvent.caller;
                    while (c) {
                        ev = c.arguments[0];
                        if (ev && Event == ev.constructor) {
                            break;
                        }
                        c = c.caller;
                    }
                }

                // IE events that target non-browser objects (e.g., VML
                // canvas) will sometimes throw errors when you try to
                // inspect the properties of the event target.  We try to
                // detect this condition, and provide a dummy target (the bound
                // element) to eliminate spurious errors.  

                // the implementation caused unexpected results in some 
                // implementations, so this has been rolled back for now
                /* 
                if (ev && this.isIE) {

                    try {

                        var el = ev.srcElement;

                    } catch(ex) {

                         
                        ev.target = boundEl;
                    }

                }
                */

                return ev;
            },

            /**
             * Returns the charcode for an event
             * @method getCharCode
             * @param {Event} ev the event
             * @return {int} the event's charCode
             * @static
             */
            getCharCode: function(ev) {
                var code = ev.keyCode || ev.charCode || 0;

                // webkit normalization
                if (YAHOO.env.ua.webkit && (code in webkitKeymap)) {
                    code = webkitKeymap[code];
                }
                return code;
            },

            /**
             * Locating the saved event handler data by function ref
             *
             * @method _getCacheIndex
             * @static
             * @private
             */
            _getCacheIndex: function(el, sType, fn) {
                for (var i=0,len=listeners.length; i<len; ++i) {
                    var li = listeners[i];
                    if ( li                 && 
                         li[this.FN] == fn  && 
                         li[this.EL] == el  && 
                         li[this.TYPE] == sType ) {
                        return i;
                    }
                }

                return -1;
            },

            /**
             * Generates an unique ID for the element if it does not already 
             * have one.
             * @method generateId
             * @param el the element to create the id for
             * @return {string} the resulting id of the element
             * @static
             */
            generateId: function(el) {
                var id = el.id;

                if (!id) {
                    id = "yuievtautoid-" + counter;
                    ++counter;
                    el.id = id;
                }

                return id;
            },


            /**
             * We want to be able to use getElementsByTagName as a collection
             * to attach a group of events to.  Unfortunately, different 
             * browsers return different types of collections.  This function
             * tests to determine if the object is array-like.  It will also 
             * fail if the object is an array, but is empty.
             * @method _isValidCollection
             * @param o the object to test
             * @return {boolean} true if the object is array-like and populated
             * @static
             * @private
             */
            _isValidCollection: function(o) {
                try {
                    return ( o                     && // o is something
                             typeof o !== "string" && // o is not a string
                             o.length              && // o is indexed
                             !o.tagName            && // o is not an HTML element
                             !o.alert              && // o is not a window
                             typeof o[0] !== "undefined" );
                } catch(ex) {
                    return false;
                }

            },

            /**
             * @private
             * @property elCache
             * DOM element cache
             * @static
             * @deprecated Elements are not cached due to issues that arise when
             * elements are removed and re-added
             */
            elCache: {},

            /**
             * We cache elements bound by id because when the unload event 
             * fires, we can no longer use document.getElementById
             * @method getEl
             * @static
             * @private
             * @deprecated Elements are not cached any longer
             */
            getEl: function(id) {
                return (typeof id === "string") ? document.getElementById(id) : id;
            },

            /**
             * Clears the element cache
             * @deprecated Elements are not cached any longer
             * @method clearCache
             * @static
             * @private
             */
            clearCache: function() { },

            /**
             * Custom event the fires when the dom is initially usable
             * @event DOMReadyEvent
             */
            DOMReadyEvent: new YAHOO.util.CustomEvent("DOMReady", this),

            /**
             * hook up any deferred listeners
             * @method _load
             * @static
             * @private
             */
            _load: function(e) {

                if (!loadComplete) {
                    loadComplete = true;
                    var EU = YAHOO.util.Event;

                    // Just in case DOMReady did not go off for some reason
                    EU._ready();

                    // Available elements may not have been detected before the
                    // window load event fires. Try to find them now so that the
                    // the user is more likely to get the onAvailable notifications