eventmanager.js

Ext JS是一个创建丰富互联网应用程序的跨浏览器的JavaScrip库。它包含：高效率

/*
 * Ext JS Library 3.0 Pre-alpha
 * Copyright(c) 2006-2008, Ext JS, LLC.
 * [e-mail]
 * 
 * http://extjs.com/license
 */

/**
 * @class Ext.EventManager
 * Registers event handlers that want to receive a normalized EventObject instead of the standard browser event and provides
 * several useful events directly.
 * See {@link Ext.EventObject} for more details on normalized event objects.
 * @singleton
 */
Ext.EventManager = function(){
    var docReadyEvent, 
    	docReadyProcId, 
    	docReadyState = false,    	
    	E = Ext.lib.Event,
    	D = Ext.lib.Dom,
    	DOC = document,
    	WINDOW = window,
    	IEDEFERED = "ie-deferred-loader",
    	DOMCONTENTLOADED = "DOMContentLoaded",
    	elHash = {},
    	propRe = /^(?:scope|delay|buffer|single|stopEvent|preventDefault|stopPropagation|normalized|args|delegate)$/;

    /// There is some jquery work around stuff here that isn't needed in Ext Core.
    function addListener(el, ename, fn, wrap, scope){	    
        var id = Ext.id(el),
        	es = elHash[id] = elHash[id] || {};     	
       
        (es[ename] = es[ename] || []).push([fn, wrap, scope]);
        E.on(el, ename, wrap);

        // this is a workaround for jQuery and should somehow be removed from Ext Core in the future
        // without breaking ExtJS.
        if(ename == "mousewheel" && el.addEventListener){ // workaround for jQuery
        	var args = ["DOMMouseScroll", wrap, false];
        	el.addEventListener.apply(el, args);
            E.on(window, 'unload', function(){
	            el.removeEventListener.apply(el, args);                
            });
        }
        if(ename == "mousedown" && el == document){ // fix stopped mousedowns on the document
            Ext.EventManager.stoppedMouseDownEvent.addListener(wrap);
        }
    };
    
    function fireDocReady(){
        if(!docReadyState){            
            Ext.isReady = docReadyState = true;
            if(docReadyProcId){
                clearInterval(docReadyProcId);
            }
            if(Ext.isGecko || Ext.isOpera) {
                DOC.removeEventListener(DOMCONTENTLOADED, fireDocReady, false);
            }
            if(Ext.isIE){
                var defer = DOC.getElementById(IEDEFERED);
                if(defer){
                    defer.onreadystatechange = null;
                    defer.parentNode.removeChild(defer);
                }
            }
            if(docReadyEvent){
                docReadyEvent.fire();
                docReadyEvent.clearListeners();
            }
        }
    };

    function initDocReady(){
	    var COMPLETE = "complete";
	    	
        docReadyEvent = new Ext.util.Event();
        if (Ext.isGecko || Ext.isOpera) {
            DOC.addEventListener(DOMCONTENTLOADED, fireDocReady, false);
        } else if (Ext.isIE){
            DOC.write("<s"+'cript id=' + IEDEFERED + ' defer="defer" src="/'+'/:"></s'+"cript>");            
            DOC.getElementById(IEDEFERED).onreadystatechange = function(){
                if(this.readyState == COMPLETE){
                    fireDocReady();
                }
            };
        } else if (Ext.isWebKit){
            docReadyProcId = setInterval(function(){                
                if(DOC.readyState == COMPLETE) {
                    fireDocReady();
                 }
            }, 10);
        }
        // no matter what, make sure it fires on load
        E.on(WINDOW, "load", fireDocReady);
    };

    function createTargeted(h, o){
        return function(){
	        var args = Ext.toArray(arguments);
            if(o.target == Ext.EventObject.setEvent(args[0]).target){
                h.apply(this, args);
            }
        };
    };    
    
    function createBuffered(h, o){
        var task = new Ext.util.DelayedTask(h);
        return function(e){
            // create new event object impl so new events don't wipe out properties            
            task.delay(o.buffer, h, null, [new Ext.EventObjectImpl(e)]);
        };
    };

    function createSingle(h, el, ename, fn, scope){
        return function(e){
            Ext.EventManager.removeListener(el, ename, fn, scope);
            h(e);
        };
    };

    function createDelayed(h, o){
        return function(e){
            // create new event object impl so new events don't wipe out properties   
            e = new Ext.EventObjectImpl(e);
            setTimeout(function(){
                h(e);
            }, o.delay || 10);
        };
    };

    function listen(element, ename, opt, fn, scope){
        var o = !Ext.isObject(opt) ? {} : opt,
        	el = Ext.getDom(element);
        	
        fn = fn || o.fn; 
        scope = scope || o.scope;
        
        if(!el){
            throw "Error listening for \"" + ename + '\". Element "' + element + '" doesn\'t exist.';
        }
        function h(e){
            // prevent errors while unload occurring
            if(!Ext){// !window[xname]){  ==> can't we do this? 
                return;
            }
            e = Ext.EventObject.setEvent(e);
            var t;
            if (o.delegate) {
                if(!(t = e.getTarget(o.delegate, el))){
                    return;
                }
            } else {
                t = e.target;
            }            
            if (o.stopEvent) {
                e.stopEvent();
            }
            if (o.preventDefault) {
               e.preventDefault();
            }
            if (o.stopPropagation) {
                e.stopPropagation();
            }
            if (o.normalized) {
                e = e.browserEvent;
            }
            
            fn.call(scope || el, e, t, o);
        };
        if(o.target){
            h = createTargeted(h, o);
        }
        if(o.delay){
            h = createDelayed(h, o);
        }
        if(o.single){
            h = createSingle(h, el, ename, fn, scope);
        }
        if(o.buffer){
            h = createBuffered(h, o);
        }

        addListener(el, ename, fn, h, scope);
        return h;
    };

    var pub = {
	    /**
	     * Appends an event handler to an element.  The shorthand version {@link #on} is equivalent.  Typically you will
	     * use {@link Ext.Element#addListener} directly on an Element in favor of calling this version.
	     * @param {String/HTMLElement} el The html element or id to assign the event handler to
	     * @param {String} eventName The type of event to listen for
	     * @param {Function} handler The handler function the event invokes This function is passed
	     * the following parameters:<ul>
	     * <li>evt : EventObject<div class="sub-desc">The {@link Ext.EventObject EventObject} describing the event.</div></li>
	     * <li>t : Element<div class="sub-desc">The {@link Ext.Element Element} which was the target of the event.
	     * Note that this may be filtered by using the <tt>delegate</tt> option.</div></li>
	     * <li>o : Object<div class="sub-desc">The options object from the addListener call.</div></li>
	     * </ul>
	     * @param {Object} scope (optional) The scope in which to execute the handler
	     * function (the handler function's "this" context)
	     * @param {Object} options (optional) An object containing handler configuration properties.
	     * This may contain any of the following properties:<ul>
	     * <li>scope {Object} : The scope in which to execute the handler function. The handler function's "this" context.</li>
	     * <li>delegate {String} : A simple selector to filter the target or look for a descendant of the target</li>
	     * <li>stopEvent {Boolean} : True to stop the event. That is stop propagation, and prevent the default action.</li>
	     * <li>preventDefault {Boolean} : True to prevent the default action</li>
	     * <li>stopPropagation {Boolean} : True to prevent event propagation</li>
	     * <li>normalized {Boolean} : False to pass a browser event to the handler function instead of an Ext.EventObject</li>
	     * <li>delay {Number} : The number of milliseconds to delay the invocation of the handler after te event fires.</li>
	     * <li>single {Boolean} : True to add a handler to handle just the next firing of the event, and then remove itself.</li>
	     * <li>buffer {Number} : Causes the handler to be scheduled to run in an {@link Ext.util.DelayedTask} delayed
	     * by the specified number of milliseconds. If the event fires again within that time, the original
	     * handler is <em>not</em> invoked, but the new handler is scheduled in its place.</li>
	     * <li>target {Element} : Only call the handler if the event was fired on the target Element, <i>not</i>
	     * if the event was bubbled up from a child node.</li>
	     * </ul><br>
	     * <p>See {@link Ext.Element#addListener} for examples of how to use these options.</p>
	     */
		addListener : function(element, eventName, fn, scope, options){		     		     		     
            if(Ext.isObject(eventName)){                
	            var o = eventName, e, val;
                for(e in o){
	                val = o[e];
                    if(!propRe.test(e)){                            		         
	                    if(Ext.isFunction(val)){
	                        // shared options
	                        listen(element, e, o, val, o.scope);
	                    }else{
	                        // individual options
	                        listen(element, e, val);
	                    }
                    }
                }
            } else {
            	listen(element, eventName, options, fn, scope);
        	}
        },
        
        /**
         * Removes an event handler from an element.  The shorthand version {@link #un} is equivalent.  Typically
         * you will use {@link Ext.Element#removeListener} directly on an Element in favor of calling this version.
         * @param {String/HTMLElement} el The id or html element from which to remove the event
         * @param {String} eventName The type of event
         * @param {Function} fn The handler function to remove
         */
        removeListener : function(element, eventName, fn, scope){            
            var el = Ext.getDom(element),
                id = Ext.id(el),
        	    wrap;      
	        
	        Ext.each((elHash[id] || {})[eventName], function (v,i,a) {
			    if (Ext.isArray(v) && v[0] == fn && (!scope || v[2] == scope)) {		        			        
			        E.un(el, eventName, wrap = v[1]);
			        a.splice(i,1);
			        return false;			        
		        }
	        });	

            // jQuery workaround that should be removed from Ext Core
	        if(eventName == "mousewheel" && el.addEventListener && wrap){
	            el.removeEventListener("DOMMouseScroll", wrap, false);
	        }
            	        
	        if(eventName == "mousedown" && el == DOC && wrap){ // fix stopped mousedowns on the document
	            Ext.EventManager.stoppedMouseDownEvent.removeListener(wrap);
	        }
        },
        
        /**
         * Removes all event handers from an element.  Typically you will use {@link Ext.Element#removeAllListeners}
         * directly on an Element in favor of calling this version.
         * @param {String/HTMLElement} el The id or html element from which to remove the event
         */
        removeAll : function(el){
	        var id = Ext.id(el = Ext.getDom(el)), 
				es = elHash[id], 				
				ename;
	       
	        for(ename in es){
	            if(es.hasOwnProperty(ename)){	                    
	                Ext.each(es[ename], function(v) {
	                    E.un(el, ename, v.wrap);                    
	                });
	            }            
	        }
	        elHash[id] = null;       
        },

        /**
         * Fires when the document is ready (before onload and before images are loaded). Can be
         * accessed shorthanded as Ext.onReady().
         * @param {Function} fn The method the event invokes
         * @param {Object} scope (optional) An object that becomes the scope of the handler
         * @param {boolean} options (optional) An object containing standard {@link #addListener} options
         */
        onDocumentReady : function(fn, scope, options){
            if(docReadyState){ // if it already fired
                docReadyEvent.addListener(fn, scope, options);
                docReadyEvent.fire();
                docReadyEvent.clearListeners();               
            } else {
                if(!docReadyEvent) initDocReady();
                options = options || {};
	            options.delay = options.delay || 1;	            
	            docReadyEvent.addListener(fn, scope, options);
            }
        },
        
        elHash : elHash   
    };
     /**
     * Appends an event handler to an element.  Shorthand for {@link #addListener}.
     * @param {String/HTMLElement} el The html element or id to assign the event handler to
     * @param {String} eventName The type of event to listen for
     * @param {Function} handler The handler function the event invokes