The source code

    /**
     * @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,
            DETECT_NATIVE = Ext.isGecko || Ext.isWebKit || Ext.isSafari || Ext.isIE10p,
            E = Ext.lib.Event,
            D = Ext.lib.Dom,
            DOC = document,
            WINDOW = window,
            DOMCONTENTLOADED = "DOMContentLoaded",
            COMPLETE = 'complete',
            propRe = /^(?:scope|delay|buffer|single|stopEvent|preventDefault|stopPropagation|normalized|args|delegate)$/,
            /*
             * This cache is used to hold special js objects, the document and window, that don't have an id. We need to keep
             * a reference to them so we can look them up at a later point.
             */
            specialElCache = [];

         function getId(el){
            var id = false,
                i = 0,
                len = specialElCache.length,
                skip = false,
                o;

            if (el) {
                if (el.getElementById || el.navigator) {
                    // look up the id
                    for(; i < len; ++i){
                        o = specialElCache[i];
                        if(o.el === el){
                            id = o.id;
                            break;
                        }
                    }
                    if(!id){
                        // for browsers that support it, ensure that give the el the same id
                        id = Ext.id(el);
                        specialElCache.push({
                            id: id,
                            el: el
                        });
                        skip = true;
                    }
                }else{
                    id = Ext.id(el);
                }
                if(!Ext.elCache[id]){
                    Ext.Element.addToCache(new Ext.Element(el), id);
                    if(skip){
                        Ext.elCache[id].skipGC = true;
                    }
                }
            }
            return id;
         }

        /// There is some jquery work around stuff here that isn't needed in Ext Core.
        function addListener(el, ename, fn, task, wrap, scope){
            el = Ext.getDom(el);
            var id = getId(el),
                es = Ext.elCache[id].events,
                wfn;

            wfn = E.on(el, ename, wrap);
            es[ename] = es[ename] || [];

            /* 0 = Original Function,
               1 = Event Manager Wrapped Function,
               2 = Scope,
               3 = Adapter Wrapped Function,
               4 = Buffered Task
            */
            es[ename].push([fn, wrap, scope, wfn, task]);

            // this is a workaround for jQuery and should somehow be removed from Ext Core in the future
            // without breaking ExtJS.

            // workaround for jQuery
            if(el.addEventListener && ename == "mousewheel"){
                var args = ["DOMMouseScroll", wrap, false];
                el.addEventListener.apply(el, args);
                Ext.EventManager.addListener(WINDOW, 'unload', function(){
                    el.removeEventListener.apply(el, args);
                });
            }

            // fix stopped mousedowns on the document
            if(el == DOC && ename == "mousedown"){
                Ext.EventManager.stoppedMouseDownEvent.addListener(wrap);
            }
        }

        function doScrollChk(){
            /* Notes:
                 'doScroll' will NOT work in a IFRAME/FRAMESET.
                 The method succeeds but, a DOM query done immediately after -- FAILS.
              */
            if(window != top){
                return false;
            }

            try{
                DOC.documentElement.doScroll('left');
            }catch(e){
                 return false;
            }

            fireDocReady();
            return true;
        }
        /**
         * @return {Boolean} True if the document is in a 'complete' state (or was determined to
         * be true by other means). If false, the state is evaluated again until canceled.
         */
        function checkReadyState(e){

            if(Ext.isIE9m && doScrollChk()){
                return true;
            }
            if(DOC.readyState == COMPLETE){
                fireDocReady();
                return true;
            }
            docReadyState || (docReadyProcId = setTimeout(arguments.callee, 2));
            return false;
        }

        var styles;
        function checkStyleSheets(e){
            styles || (styles = Ext.query('style, link[rel=stylesheet]'));
            if(styles.length == DOC.styleSheets.length){
                fireDocReady();
                return true;
            }
            docReadyState || (docReadyProcId = setTimeout(arguments.callee, 2));
            return false;
        }

        function OperaDOMContentLoaded(e){
            DOC.removeEventListener(DOMCONTENTLOADED, arguments.callee, false);
            checkStyleSheets();
        }

        function fireDocReady(e){
            if(!docReadyState){
                docReadyState = true; //only attempt listener removal once

                if(docReadyProcId){
                    clearTimeout(docReadyProcId);
                }
                if(DETECT_NATIVE) {
                    DOC.removeEventListener(DOMCONTENTLOADED, fireDocReady, false);
                }
                if(Ext.isIE9m && checkReadyState.bindIE){  //was this was actually set ??
                    DOC.detachEvent('onreadystatechange', checkReadyState);
                }
                E.un(WINDOW, "load", arguments.callee);
            }
            if(docReadyEvent && !Ext.isReady){
                Ext.isReady = true;
                docReadyEvent.fire();
                docReadyEvent.listeners = [];
            }

        }

        function initDocReady(){
            docReadyEvent || (docReadyEvent = new Ext.util.Event());
            if (DETECT_NATIVE) {
                DOC.addEventListener(DOMCONTENTLOADED, fireDocReady, false);
            }
            /*
             * Handle additional (exceptional) detection strategies here
             */
            if (Ext.isIE9m){
                //Use readystatechange as a backup AND primary detection mechanism for a FRAME/IFRAME
                //See if page is already loaded
                if(!checkReadyState()){
                    checkReadyState.bindIE = true;
                    DOC.attachEvent('onreadystatechange', checkReadyState);
                }

            }else if(Ext.isOpera ){
                /* Notes:
                   Opera needs special treatment needed here because CSS rules are NOT QUITE
                   available after DOMContentLoaded is raised.
                */

                //See if page is already loaded and all styleSheets are in place
                (DOC.readyState == COMPLETE && checkStyleSheets()) ||
                    DOC.addEventListener(DOMCONTENTLOADED, OperaDOMContentLoaded, false);

            }else if (Ext.isWebKit){
                //Fallback for older Webkits without DOMCONTENTLOADED support
                checkReadyState();
            }
            // 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, task){
            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, fn){
            return function(e){
                var task = new Ext.util.DelayedTask(h);
                if(!fn.tasks) {
                    fn.tasks = [];
                }
                fn.tasks.push(task);
                task.delay(o.delay || 10, h, null, [new Ext.EventObjectImpl(e)]);
            };
        }

        function listen(element, ename, opt, fn, scope){
            var o = (!opt || typeof opt == "boolean") ? {} : opt,
                el = Ext.getDom(element), task;

            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 === false) {
                    e = e.browserEvent;
                }

                fn.call(scope || el, e, t, o);
            }
            if(o.target){
                h = createTargeted(h, o);
            }
            if(o.delay){
                h = createDelayed(h, o, fn);
            }
            if(o.single){
                h = createSingle(h, el, ename, fn, scope);
            }
            if(o.buffer){
                task = new Ext.util.DelayedTask(h);
                h = createBuffered(h, o, task);
            }

            addListener(el, ename, fn, task, 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 name of the 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 (<b><code>this</code></b> reference) in which the handler function is executed. <b>Defaults to the Element</b>.
             * @param {Object} options (optional) An object containing handler configuration properties.
             * This may contain any of the following properties:<ul>
             * <li>scope : Object<div class="sub-desc">The scope (<b><code>this</code></b> reference) in which the handler function is executed. <b>Defaults to the Element</b>.</div></li>
             * <li>delegate : String<div class="sub-desc">A simple selector to filter the target or look for a descendant of the target</div></li>
             * <li>stopEvent : Boolean<div class="sub-desc">True to stop the event. That is stop propagation, and prevent the default action.</div></li>
             * <li>preventDefault : Boolean<div class="sub-desc">True to prevent the default action</div></li>
             * <li>stopPropagation : Boolean<div class="sub-desc">True to prevent event propagation</div></li>
             * <li>normalized : Boolean<div class="sub-desc">False to pass a browser event to the handler function instead of an Ext.EventObject</div></li>
             * <li>delay : Number<div class="sub-desc">The number of milliseconds to delay the invocation of the handler after te event fires.</div></li>
             * <li>single : Boolean<div class="sub-desc">True to add a handler to handle just the next firing of the event, and then remove itself.</div></li>
             * <li>buffer : Number<div class="sub-desc">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.</div></li>
             * <li>target : Element<div class="sub-desc">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.</div></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(typeof eventName == 'object'){
                    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 listener.
             * @param {String} eventName The name of the event.
             * @param {Function} fn The handler function to remove. <b>This must be a reference to the function passed into the {@link #addListener} call.</b>
             * @param {Object} scope If a scope (<b><code>this</code></b> reference) was specified when the listener was added,
             * then this must refer to the same object.
             */
            removeListener : function(el, eventName, fn, scope){
                el = Ext.getDom(el);
                var id = getId(el),
                    f = el && (Ext.elCache[id].events)[eventName] || [],
                    wrap, i, l, k, len, fnc;

                for (i = 0, len = f.length; i < len; i++) {

                    /* 0 = Original Function,
                       1 = Event Manager Wrapped Function,
                       2 = Scope,
                       3 = Adapter Wrapped Function,
                       4 = Buffered Task
                    */
                    if (Ext.isArray(fnc = f[i]) && fnc[0] == fn && (!scope || fnc[2] == scope)) {
                        if(fnc[4]) {
                            fnc[4].cancel();
                        }
                        k = fn.tasks && fn.tasks.length;
                        if(k) {
                            while(k--) {
                                fn.tasks[k].cancel();
                            }
                            delete fn.tasks;
                        }
                        wrap = fnc[1];
                        E.un(el, eventName, E.extAdapter ? fnc[3] : wrap);

                        // jQuery workaround that should be removed from Ext Core
                        if(wrap && el.addEventListener && eventName == "mousewheel"){
                            el.removeEventListener("DOMMouseScroll", wrap, false);
                        }

                        // fix stopped mousedowns on the document
                        if(wrap && el == DOC && eventName == "mousedown"){
                            Ext.EventManager.stoppedMouseDownEvent.removeListener(wrap);
                        }

                        f.splice(i, 1);
                        if (f.length === 0) {
                            delete Ext.elCache[id].events[eventName];
                        }
                        for (k in Ext.elCache[id].events) {
                            return false;
                        }
                        Ext.elCache[id].events = {};
                        return false;
                    }
                }
            },

            /**
             * 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 all event handlers.
             */
            removeAll : function(el){
                el = Ext.getDom(el);
                var id = getId(el),
                    ec = Ext.elCache[id] || {},
                    es = ec.events || {},
                    f, i, len, ename, fn, k, wrap;

                for(ename in es){
                    if(es.hasOwnProperty(ename)){
                        f = es[ename];
                        /* 0 = Original Function,
                           1 = Event Manager Wrapped Function,
                           2 = Scope,
                           3 = Adapter Wrapped Function,
                           4 = Buffered Task
                        */
                        for (i = 0, len = f.length; i < len; i++) {
                            fn = f[i];
                            if(fn[4]) {
                                fn[4].cancel();
                            }
                            if(fn[0].tasks && (k = fn[0].tasks.length)) {
                                while(k--) {
                                    fn[0].tasks[k].cancel();
                                }
                                delete fn.tasks;
                            }
                            wrap =  fn[1];
                            E.un(el, ename, E.extAdapter ? fn[3] : wrap);

                            // jQuery workaround that should be removed from Ext Core
                            if(el.addEventListener && wrap && ename == "mousewheel"){
                                el.removeEventListener("DOMMouseScroll", wrap, false);
                            }

                            // fix stopped mousedowns on the document
                            if(wrap && el == DOC &&  ename == "mousedown"){
                                Ext.EventManager.stoppedMouseDownEvent.removeListener(wrap);
                            }
                        }
                    }
                }
                if (Ext.elCache[id]) {
                    Ext.elCache[id].events = {};
                }
            },

            getListeners : function(el, eventName) {
                el = Ext.getDom(el);
                var id = getId(el),
                    ec = Ext.elCache[id] || {},
                    es = ec.events || {},
                    results = [];
                if (es && es[eventName]) {
                    return es[eventName];
                } else {
                    return null;
                }
            },

            removeFromSpecialCache: function(o) {
                var i = 0,
                    len = specialElCache.length;

                for (; i < len; ++i) {
                    if (specialElCache[i].el == o) {
                        specialElCache.splice(i, 1);
                    }
                }
            },

            purgeElement : function(el, recurse, eventName) {
                el = Ext.getDom(el);
                var id = getId(el),
                    ec = Ext.elCache[id] || {},
                    es = ec.events || {},
                    i, f, len;
                if (eventName) {
                    if (es && es.hasOwnProperty(eventName)) {
                        f = es[eventName];
                        for (i = 0, len = f.length; i < len; i++) {
                            Ext.EventManager.removeListener(el, eventName, f[i][0]);
                        }
                    }
                } else {
                    Ext.EventManager.removeAll(el);
                }
                if (recurse && el && el.childNodes) {
                    for (i = 0, len = el.childNodes.length; i < len; i++) {
                        Ext.EventManager.purgeElement(el.childNodes[i], recurse, eventName);
                    }
                }
            },

            _unload : function() {
                var el;
                for (el in Ext.elCache) {
                    Ext.EventManager.removeAll(el);
                }
                delete Ext.elCache;
                delete Ext.Element._flyweights;

                // Abort any outstanding Ajax requests
                var c,
                    conn,
                    tid,
                    ajax = Ext.lib.Ajax;
                (typeof ajax.conn == 'object') ? conn = ajax.conn : conn = {};
                for (tid in conn) {
                    c = conn[tid];
                    if (c) {
                        ajax.abort({conn: c, tId: tid});
                    }
                }
            },
            /**
             * Adds a listener to be notified 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) The scope (<code>this</code> reference) in which the handler function executes. Defaults to the browser window.
             * @param {boolean} options (optional) Options object as passed to {@link Ext.Element#addListener}. It is recommended that the options
             * <code>{single: true}</code> be used so that the handler is removed on first invocation.
             */
            onDocumentReady : function(fn, scope, options){
                if (Ext.isReady) { // if it already fired or document.body is present
                    docReadyEvent || (docReadyEvent = new Ext.util.Event());
                    docReadyEvent.addListener(fn, scope, options);
                    docReadyEvent.fire();
                    docReadyEvent.listeners = [];
                } else {
                    if (!docReadyEvent) {
                        initDocReady();
                    }
                    options = options || {};
                    options.delay = options.delay || 1;
                    docReadyEvent.addListener(fn, scope, options);
                }
            },

            /**
             * Forces a document ready state transition for the framework.  Used when Ext is loaded
             * into a DOM structure AFTER initial page load (Google API or other dynamic load scenario.
             * Any pending 'onDocumentReady' handlers will be fired (if not already handled).
             */
            fireDocReady  : fireDocReady
        };
         /**
         * 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 name of the event to listen for.
         * @param {Function} handler The handler function the event invokes.
         * @param {Object} scope (optional) (<code>this</code> reference) in which the handler function executes. <b>Defaults to the Element</b>.
         * @param {Object} options (optional) An object containing standard {@link #addListener} options
         * @member Ext.EventManager
         * @method on
         */
        pub.on = pub.addListener;
        /**
         * Removes an event handler from an element.  Shorthand for {@link #removeListener}.
         * @param {String/HTMLElement} el The id or html element from which to remove the listener.
         * @param {String} eventName The name of the event.
         * @param {Function} fn The handler function to remove. <b>This must be a reference to the function passed into the {@link #on} call.</b>
         * @param {Object} scope If a scope (<b><code>this</code></b> reference) was specified when the listener was added,
         * then this must refer to the same object.
         * @member Ext.EventManager
         * @method un
         */
        pub.un = pub.removeListener;

        pub.stoppedMouseDownEvent = new Ext.util.Event();
        return pub;
    }();
    /**
      * Adds a listener to be notified when the document is ready (before onload and before images are loaded). Shorthand of {@link Ext.EventManager#onDocumentReady}.
      * @param {Function} fn The method the event invokes.
      * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the handler function executes. Defaults to the browser window.
      * @param {boolean} options (optional) Options object as passed to {@link Ext.Element#addListener}. It is recommended that the options
      * <code>{single: true}</code> be used so that the handler is removed on first invocation.
      * @member Ext
      * @method onReady
     */
    Ext.onReady = Ext.EventManager.onDocumentReady;

    //Initialize doc classes
    (function(){
        var initExtCss = function() {
            // find the body element
            var bd = document.body || document.getElementsByTagName('body')[0];
            if (!bd) {
                return false;
            }

            var cls = [];

            if (Ext.isIE) {
                // Only treat IE9 and less like IE in the css
                if (!Ext.isIE10p) {
                    cls.push('ext-ie');
                }
                if (Ext.isIE6) {
                    cls.push('ext-ie6');
                } else if (Ext.isIE7) {
                    cls.push('ext-ie7', 'ext-ie7m');
                } else if (Ext.isIE8) {
                    cls.push('ext-ie8', 'ext-ie8m');
                } else if (Ext.isIE9) {
                    cls.push('ext-ie9', 'ext-ie9m');
                } else if (Ext.isIE10) {
                    cls.push('ext-ie10');
                }
            }

            if (Ext.isGecko) {
                if (Ext.isGecko2) {
                    cls.push('ext-gecko2');
                } else {
                    cls.push('ext-gecko3');
                }
            }

            if (Ext.isOpera) {
                cls.push('ext-opera');
            }

            if (Ext.isWebKit) {
                cls.push('ext-webkit');
            }

            if (Ext.isSafari) {
                cls.push("ext-safari " + (Ext.isSafari2 ? 'ext-safari2' : (Ext.isSafari3 ? 'ext-safari3' : 'ext-safari4')));
            } else if(Ext.isChrome) {
                cls.push("ext-chrome");
            }

            if (Ext.isMac) {
                cls.push("ext-mac");
            }
            if (Ext.isLinux) {
                cls.push("ext-linux");
            }

            // add to the parent to allow for selectors like ".ext-strict .ext-ie"
            if (Ext.isStrict || Ext.isBorderBox) {
                var p = bd.parentNode;
                if (p) {
                    if (!Ext.isStrict) {
                        Ext.fly(p, '_internal').addClass('x-quirks');
                        if (Ext.isIE9m && !Ext.isStrict) {
                            Ext.isIEQuirks = true;
                        }
                    }
                    Ext.fly(p, '_internal').addClass(((Ext.isStrict && Ext.isIE ) || (!Ext.enableForcedBoxModel && !Ext.isIE)) ? ' ext-strict' : ' ext-border-box');
                }
            }
            // Forced border box model class applied to all elements. Bypassing javascript based box model adjustments
            // in favor of css.  This is for non-IE browsers.
            if (Ext.enableForcedBoxModel && !Ext.isIE) {
                Ext.isForcedBorderBox = true;
                cls.push("ext-forced-border-box");
            }

            Ext.fly(bd, '_internal').addClass(cls);
            return true;
        };

        if (!initExtCss()) {
            Ext.onReady(initExtCss);
        }
    })();

    // Code used to detect certain browser feature/quirks/bugs at startup.
    (function(){
        /**
         * @class Ext.supports
         * @ignore
         */
        var supports = Ext.apply(Ext.supports, {
            /**
             * In Webkit, there is an issue with getting the margin right property, see
             * https://bugs.webkit.org/show_bug.cgi?id=13343
             */
            correctRightMargin: true,

            /**
             * Webkit browsers return rgba(0, 0, 0) when a transparent color is used
             */
            correctTransparentColor: true,

            /**
             * IE uses styleFloat, not cssFloat for the float property.
             */
            cssFloat: true
        });

        var supportTests = function(){
                var div = document.createElement('div'),
                    doc = document,
                    view,
                    last;

                div.innerHTML = '<div style="height:30px;width:50px;"><div style="height:20px;width:20px;"></div></div><div style="float:left;background-color:transparent;">';
                doc.body.appendChild(div);
                last = div.lastChild;

                if((view = doc.defaultView)){
                    if(view.getComputedStyle(div.firstChild.firstChild, null).marginRight != '0px'){
                        supports.correctRightMargin = false;
                    }
                    if(view.getComputedStyle(last, null).backgroundColor != 'transparent'){
                        supports.correctTransparentColor = false;
                    }
                }
                supports.cssFloat = !!last.style.cssFloat;
                doc.body.removeChild(div);
        };

        if (Ext.isReady) {
            supportTests();
        } else {
            Ext.onReady(supportTests);
        }
    })();

    /**
     * @class Ext.EventObject
     * Just as {@link Ext.Element} wraps around a native DOM node, Ext.EventObject
     * wraps the browser's native event-object normalizing cross-browser differences,
     * such as which mouse button is clicked, keys pressed, mechanisms to stop
     * event-propagation along with a method to prevent default actions from taking place.
     * <p>For example:</p>
     * <pre><code>
    function handleClick(e, t){ // e is not a standard event object, it is a Ext.EventObject
        e.preventDefault();
        var target = e.getTarget(); // same as t (the target HTMLElement)
        ...
    }
    var myDiv = {@link Ext#get Ext.get}("myDiv");  // get reference to an {@link Ext.Element}
    myDiv.on(         // 'on' is shorthand for addListener
        "click",      // perform an action on click of myDiv
        handleClick   // reference to the action handler
    );
    // other methods to do the same:
    Ext.EventManager.on("myDiv", 'click', handleClick);
    Ext.EventManager.addListener("myDiv", 'click', handleClick);
     </code></pre>
     * @singleton
     */
    Ext.EventObject = function(){
        var E = Ext.lib.Event,
            clickRe = /(dbl)?click/,
            // safari keypress events for special keys return bad keycodes
            safariKeys = {
                3 : 13, // enter
                63234 : 37, // left
                63235 : 39, // right
                63232 : 38, // up
                63233 : 40, // down
                63276 : 33, // page up
                63277 : 34, // page down
                63272 : 46, // delete
                63273 : 36, // home
                63275 : 35  // end
            },
            // normalize button clicks
            btnMap = Ext.isIE ? {1:0,4:1,2:2} : {0:0,1:1,2:2};

        Ext.EventObjectImpl = function(e){
            if(e){
                this.setEvent(e.browserEvent || e);
            }
        };

        Ext.EventObjectImpl.prototype = {
               /** @private */
            setEvent : function(e){
                var me = this;
                if(e == me || (e && e.browserEvent)){ // already wrapped
                    return e;
                }
                me.browserEvent = e;
                if(e){
                    // normalize buttons
                    me.button = e.button ? btnMap[e.button] : (e.which ? e.which - 1 : -1);
                    if(clickRe.test(e.type) && me.button == -1){
                        me.button = 0;
                    }
                    me.type = e.type;
                    me.shiftKey = e.shiftKey;
                    // mac metaKey behaves like ctrlKey
                    me.ctrlKey = e.ctrlKey || e.metaKey || false;
                    me.altKey = e.altKey;
                    // in getKey these will be normalized for the mac
                    me.keyCode = e.keyCode;
                    me.charCode = e.charCode;
                    // cache the target for the delayed and or buffered events
                    me.target = E.getTarget(e);
                    // same for XY
                    me.xy = E.getXY(e);
                }else{
                    me.button = -1;
                    me.shiftKey = false;
                    me.ctrlKey = false;
                    me.altKey = false;
                    me.keyCode = 0;
                    me.charCode = 0;
                    me.target = null;
                    me.xy = [0, 0];
                }
                return me;
            },

            /**
             * Stop the event (preventDefault and stopPropagation)
             */
            stopEvent : function(){
                var me = this;
                if(me.browserEvent){
                    if(me.browserEvent.type == 'mousedown'){
                        Ext.EventManager.stoppedMouseDownEvent.fire(me);
                    }
                    E.stopEvent(me.browserEvent);
                }
            },

            /**
             * Prevents the browsers default handling of the event.
             */
            preventDefault : function(){
                if(this.browserEvent){
                    E.preventDefault(this.browserEvent);
                }
            },

            /**
             * Cancels bubbling of the event.
             */
            stopPropagation : function(){
                var me = this;
                if(me.browserEvent){
                    if(me.browserEvent.type == 'mousedown'){
                        Ext.EventManager.stoppedMouseDownEvent.fire(me);
                    }
                    E.stopPropagation(me.browserEvent);
                }
            },

            /**
             * Gets the character code for the event.
             * @return {Number}
             */
            getCharCode : function(){
                return this.charCode || this.keyCode;
            },

            /**
             * Returns a normalized keyCode for the event.
             * @return {Number} The key code
             */
            getKey : function(){
                return this.normalizeKey(this.keyCode || this.charCode);
            },

            // private
            normalizeKey: function(k){
                return Ext.isSafari ? (safariKeys[k] || k) : k;
            },

            /**
             * Gets the x coordinate of the event.
             * @return {Number}
             */
            getPageX : function(){
                return this.xy[0];
            },

            /**
             * Gets the y coordinate of the event.
             * @return {Number}
             */
            getPageY : function(){
                return this.xy[1];
            },

            /**
             * Gets the page coordinates of the event.
             * @return {Array} The xy values like [x, y]
             */
            getXY : function(){
                return this.xy;
            },

            /**
             * Gets the target for the event.
             * @param {String} selector (optional) A simple selector to filter the target or look for an ancestor of the target
             * @param {Number/Mixed} maxDepth (optional) The max depth to
                    search as a number or element (defaults to 10 || document.body)
             * @param {Boolean} returnEl (optional) True to return a Ext.Element object instead of DOM node
             * @return {HTMLelement}
             */
            getTarget : function(selector, maxDepth, returnEl){
                return selector ? Ext.fly(this.target).findParent(selector, maxDepth, returnEl) : (returnEl ? Ext.get(this.target) : this.target);
            },

            /**
             * Gets the related target.
             * @return {HTMLElement}
             */
            getRelatedTarget : function(){
                return this.browserEvent ? E.getRelatedTarget(this.browserEvent) : null;
            },

            /**
             * Normalizes mouse wheel delta across browsers
             * @return {Number} The delta
             */
            getWheelDelta : function(){
                var e = this.browserEvent;
                var delta = 0;
                if(e.wheelDelta){ /* IE/Opera. */
                    delta = e.wheelDelta/120;
                }else if(e.detail){ /* Mozilla case. */
                    delta = -e.detail/3;
                }
                return delta;
            },

            /**
            * Returns true if the target of this event is a child of el.  Unless the allowEl parameter is set, it will return false if if the target is el.
            * Example usage:<pre><code>
            // Handle click on any child of an element
            Ext.getBody().on('click', function(e){
                if(e.within('some-el')){
                    alert('Clicked on a child of some-el!');
                }
            });

            // Handle click directly on an element, ignoring clicks on child nodes
            Ext.getBody().on('click', function(e,t){
                if((t.id == 'some-el') && !e.within(t, true)){
                    alert('Clicked directly on some-el!');
                }
            });
            </code></pre>
             * @param {Mixed} el The id, DOM element or Ext.Element to check
             * @param {Boolean} related (optional) true to test if the related target is within el instead of the target
             * @param {Boolean} allowEl (optional) true to also check if the passed element is the target or related target
             * @return {Boolean}
             */
            within : function(el, related, allowEl){
                if(el){
                    var t = this[related ? "getRelatedTarget" : "getTarget"]();
                    return t && ((allowEl ? (t == Ext.getDom(el)) : false) || Ext.fly(el).contains(t));
                }
                return false;
            }
         };

        return new Ext.EventObjectImpl();
    }();