The source code

    /**
     * @class Ext.Window
     * @extends Ext.Panel
     * <p>A specialized panel intended for use as an application window.  Windows are floated, {@link #resizable}, and
     * {@link #draggable} by default.  Windows can be {@link #maximizable maximized} to fill the viewport,
     * restored to their prior size, and can be {@link #minimize}d.</p>
     * <p>Windows can also be linked to a {@link Ext.WindowGroup} or managed by the {@link Ext.WindowMgr} to provide
     * grouping, activation, to front, to back and other application-specific behavior.</p>
     * <p>By default, Windows will be rendered to document.body. To {@link #constrain} a Window to another element
     * specify {@link Ext.Component#renderTo renderTo}.</p>
     * <p><b>Note:</b> By default, the <code>{@link #closable close}</code> header tool <i>destroys</i> the Window resulting in
     * destruction of any child Components. This makes the Window object, and all its descendants <b>unusable</b>. To enable
     * re-use of a Window, use <b><code>{@link #closeAction closeAction: 'hide'}</code></b>.</p>
     * @constructor
     * @param {Object} config The config object
     * @xtype window
     */
    Ext.Window = Ext.extend(Ext.Panel, {
        /**
         * @cfg {Number} x
         * The X position of the left edge of the window on initial showing. Defaults to centering the Window within
         * the width of the Window's container {@link Ext.Element Element) (The Element that the Window is rendered to).
         */
        /**
         * @cfg {Number} y
         * The Y position of the top edge of the window on initial showing. Defaults to centering the Window within
         * the height of the Window's container {@link Ext.Element Element) (The Element that the Window is rendered to).
         */
        /**
         * @cfg {Boolean} modal
         * True to make the window modal and mask everything behind it when displayed, false to display it without
         * restricting access to other UI elements (defaults to false).
         */
        /**
         * @cfg {String/Element} animateTarget
         * Id or element from which the window should animate while opening (defaults to null with no animation).
         */
        /**
         * @cfg {String} resizeHandles
         * A valid {@link Ext.Resizable} handles config string (defaults to 'all').  Only applies when resizable = true.
         */
        /**
         * @cfg {Ext.WindowGroup} manager
         * A reference to the WindowGroup that should manage this window (defaults to {@link Ext.WindowMgr}).
         */
        /**
        * @cfg {String/Number/Component} defaultButton
        * <p>Specifies a Component to receive focus when this Window is focussed.</p>
        * <p>This may be one of:</p><div class="mdetail-params"><ul>
        * <li>The index of a footer Button.</li>
        * <li>The id of a Component.</li>
        * <li>A Component.</li>
        * </ul></div>
        */
        /**
        * @cfg {Function} onEsc
        * Allows override of the built-in processing for the escape key. Default action
        * is to close the Window (performing whatever action is specified in {@link #closeAction}.
        * To prevent the Window closing when the escape key is pressed, specify this as
        * Ext.emptyFn (See {@link Ext#emptyFn}).
        */
        /**
         * @cfg {Boolean} collapsed
         * True to render the window collapsed, false to render it expanded (defaults to false). Note that if
         * {@link #expandOnShow} is true (the default) it will override the <tt>collapsed</tt> config and the window
         * will always be expanded when shown.
         */
        /**
         * @cfg {Boolean} maximized
         * True to initially display the window in a maximized state. (Defaults to false).
         */

        /**
        * @cfg {String} baseCls
        * The base CSS class to apply to this panel's element (defaults to 'x-window').
        */
        baseCls : 'x-window',
        /**
         * @cfg {Boolean} resizable
         * True to allow user resizing at each edge and corner of the window, false to disable resizing (defaults to true).
         */
        resizable : true,
        /**
         * @cfg {Boolean} draggable
         * True to allow the window to be dragged by the header bar, false to disable dragging (defaults to true).  Note
         * that by default the window will be centered in the viewport, so if dragging is disabled the window may need
         * to be positioned programmatically after render (e.g., myWindow.setPosition(100, 100);).
         */
        draggable : true,
        /**
         * @cfg {Boolean} closable
         * <p>True to display the 'close' tool button and allow the user to close the window, false to
         * hide the button and disallow closing the window (defaults to true).</p>
         * <p>By default, when close is requested by either clicking the close button in the header
         * or pressing ESC when the Window has focus, the {@link #close} method will be called. This
         * will <i>{@link Ext.Component#destroy destroy}</i> the Window and its content meaning that
         * it may not be reused.</p>
         * <p>To make closing a Window <i>hide</i> the Window so that it may be reused, set
         * {@link #closeAction} to 'hide'.
         */
        closable : true,
        /**
         * @cfg {String} closeAction
         * <p>The action to take when the close header tool is clicked:
         * <div class="mdetail-params"><ul>
         * <li><b><code>'{@link #close}'</code></b> : <b>Default</b><div class="sub-desc">
         * {@link #close remove} the window from the DOM and {@link Ext.Component#destroy destroy}
         * it and all descendant Components. The window will <b>not</b> be available to be
         * redisplayed via the {@link #show} method.
         * </div></li>
         * <li><b><code>'{@link #hide}'</code></b> : <div class="sub-desc">
         * {@link #hide} the window by setting visibility to hidden and applying negative offsets.
         * The window will be available to be redisplayed via the {@link #show} method.
         * </div></li>
         * </ul></div>
         * <p><b>Note:</b> This setting does not affect the {@link #close} method
         * which will always {@link Ext.Component#destroy destroy} the window. To
         * programatically <i>hide</i> a window, call {@link #hide}.</p>
         */
        closeAction : 'close',
        /**
         * @cfg {Boolean} constrain
         * True to constrain the window within its containing element, false to allow it to fall outside of its
         * containing element. By default the window will be rendered to document.body.  To render and constrain the
         * window within another element specify {@link #renderTo}.
         * (defaults to false).  Optionally the header only can be constrained using {@link #constrainHeader}.
         */
        constrain : false,
        /**
         * @cfg {Boolean} constrainHeader
         * True to constrain the window header within its containing element (allowing the window body to fall outside
         * of its containing element) or false to allow the header to fall outside its containing element (defaults to
         * false). Optionally the entire window can be constrained using {@link #constrain}.
         */
        constrainHeader : false,
        /**
         * @cfg {Boolean} plain
         * True to render the window body with a transparent background so that it will blend into the framing
         * elements, false to add a lighter background color to visually highlight the body element and separate it
         * more distinctly from the surrounding frame (defaults to false).
         */
        plain : false,
        /**
         * @cfg {Boolean} minimizable
         * True to display the 'minimize' tool button and allow the user to minimize the window, false to hide the button
         * and disallow minimizing the window (defaults to false).  Note that this button provides no implementation --
         * the behavior of minimizing a window is implementation-specific, so the minimize event must be handled and a
         * custom minimize behavior implemented for this option to be useful.
         */
        minimizable : false,
        /**
         * @cfg {Boolean} maximizable
         * True to display the 'maximize' tool button and allow the user to maximize the window, false to hide the button
         * and disallow maximizing the window (defaults to false).  Note that when a window is maximized, the tool button
         * will automatically change to a 'restore' button with the appropriate behavior already built-in that will
         * restore the window to its previous size.
         */
        maximizable : false,
        /**
         * @cfg {Number} minHeight
         * The minimum height in pixels allowed for this window (defaults to 100).  Only applies when resizable = true.
         */
        minHeight : 100,
        /**
         * @cfg {Number} minWidth
         * The minimum width in pixels allowed for this window (defaults to 200).  Only applies when resizable = true.
         */
        minWidth : 200,
        /**
         * @cfg {Boolean} expandOnShow
         * True to always expand the window when it is displayed, false to keep it in its current state (which may be
         * {@link #collapsed}) when displayed (defaults to true).
         */
        expandOnShow : true,

        /**
         * @cfg {Number} showAnimDuration The number of seconds that the window show animation takes if enabled.
         * Defaults to 0.25
         */
        showAnimDuration: 0.25,

        /**
         * @cfg {Number} hideAnimDuration The number of seconds that the window hide animation takes if enabled.
         * Defaults to 0.25
         */
        hideAnimDuration: 0.25,

        // inherited docs, same default
        collapsible : false,

        /**
         * @cfg {Boolean} initHidden
         * True to hide the window until show() is explicitly called (defaults to true).
         * @deprecated
         */
        initHidden : undefined,

        /**
         * @cfg {Boolean} hidden
         * Render this component hidden (default is <tt>true</tt>). If <tt>true</tt>, the
         * {@link #hide} method will be called internally.
         */
        hidden : true,

        // The following configs are set to provide the basic functionality of a window.
        // Changing them would require additional code to handle correctly and should
        // usually only be done in subclasses that can provide custom behavior.  Changing them
        // may have unexpected or undesirable results.
        /** @cfg {String} elements @hide */
        elements : 'header,body',
        /** @cfg {Boolean} frame @hide */
        frame : true,
        /** @cfg {Boolean} floating @hide */
        floating : true,

        // private
        initComponent : function(){
            this.initTools();
            Ext.Window.superclass.initComponent.call(this);
            this.addEvents(
                /**
                 * @event activate
                 * Fires after the window has been visually activated via {@link #setActive}.
                 * @param {Ext.Window} this
                 */
                /**
                 * @event deactivate
                 * Fires after the window has been visually deactivated via {@link #setActive}.
                 * @param {Ext.Window} this
                 */
                /**
                 * @event resize
                 * Fires after the window has been resized.
                 * @param {Ext.Window} this
                 * @param {Number} width The window's new width
                 * @param {Number} height The window's new height
                 */
                'resize',
                /**
                 * @event maximize
                 * Fires after the window has been maximized.
                 * @param {Ext.Window} this
                 */
                'maximize',
                /**
                 * @event minimize
                 * Fires after the window has been minimized.
                 * @param {Ext.Window} this
                 */
                'minimize',
                /**
                 * @event restore
                 * Fires after the window has been restored to its original size after being maximized.
                 * @param {Ext.Window} this
                 */
                'restore'
            );
            // for backwards compat, this should be removed at some point
            if(Ext.isDefined(this.initHidden)){
                this.hidden = this.initHidden;
            }
            if(this.hidden === false){
                this.hidden = true;
                this.show();
            }
        },

        // private
        getState : function(){
            return Ext.apply(Ext.Window.superclass.getState.call(this) || {}, this.getBox(true));
        },

        // private
        onRender : function(ct, position){
            Ext.Window.superclass.onRender.call(this, ct, position);

            if(this.plain){
                this.el.addClass('x-window-plain');
            }

            // this element allows the Window to be focused for keyboard events
            this.focusEl = this.el.createChild({
                        tag: 'a', href:'#', cls:'x-dlg-focus',
                        tabIndex:'-1', html: '&#160;'});
            this.focusEl.swallowEvent('click', true);

            this.proxy = this.el.createProxy('x-window-proxy');
            this.proxy.enableDisplayMode('block');

            if(this.modal){
                this.mask = this.container.createChild({cls:'ext-el-mask'}, this.el.dom);
                this.mask.enableDisplayMode('block');
                this.mask.hide();
                this.mon(this.mask, 'click', this.focus, this);
            }
            if(this.maximizable){
                this.mon(this.header, 'dblclick', this.toggleMaximize, this);
            }
        },

        // private
        initEvents : function(){
            Ext.Window.superclass.initEvents.call(this);
            if(this.animateTarget){
                this.setAnimateTarget(this.animateTarget);
            }

            if(this.resizable){
                this.resizer = new Ext.Resizable(this.el, {
                    minWidth: this.minWidth,
                    minHeight:this.minHeight,
                    handles: this.resizeHandles || 'all',
                    pinned: true,
                    resizeElement : this.resizerAction,
                    handleCls: 'x-window-handle'
                });
                this.resizer.window = this;
                this.mon(this.resizer, 'beforeresize', this.beforeResize, this);
            }

            if(this.draggable){
                this.header.addClass('x-window-draggable');
            }
            this.mon(this.el, 'mousedown', this.toFront, this);
            this.manager = this.manager || Ext.WindowMgr;
            this.manager.register(this);
            if(this.maximized){
                this.maximized = false;
                this.maximize();
            }
            if(this.closable){
                var km = this.getKeyMap();
                km.on(27, this.onEsc, this);
                km.disable();
            }
        },

        initDraggable : function(){
            /**
             * <p>If this Window is configured {@link #draggable}, this property will contain
             * an instance of {@link Ext.dd.DD} which handles dragging the Window's DOM Element.</p>
             * <p>This has implementations of <code>startDrag</code>, <code>onDrag</code> and <code>endDrag</code>
             * which perform the dragging action. If extra logic is needed at these points, use
             * {@link Function#createInterceptor createInterceptor} or {@link Function#createSequence createSequence} to
             * augment the existing implementations.</p>
             * @type Ext.dd.DD
             * @property dd
             */
            this.dd = new Ext.Window.DD(this);
        },

       // private
        onEsc : function(k, e){
            if (this.activeGhost) {
                this.unghost();
            }
            e.stopEvent();
            this[this.closeAction]();
        },

        // private
        beforeDestroy : function(){
            if(this.rendered){
                this.hide();
                this.clearAnchor();
                Ext.destroy(
                    this.focusEl,
                    this.resizer,
                    this.dd,
                    this.proxy,
                    this.mask
                );
            }
            Ext.Window.superclass.beforeDestroy.call(this);
        },

        // private
        onDestroy : function(){
            if(this.manager){
                this.manager.unregister(this);
            }
            Ext.Window.superclass.onDestroy.call(this);
        },

        // private
        initTools : function(){
            if(this.minimizable){
                this.addTool({
                    id: 'minimize',
                    handler: this.minimize.createDelegate(this, [])
                });
            }
            if(this.maximizable){
                this.addTool({
                    id: 'maximize',
                    handler: this.maximize.createDelegate(this, [])
                });
                this.addTool({
                    id: 'restore',
                    handler: this.restore.createDelegate(this, []),
                    hidden:true
                });
            }
            if(this.closable){
                this.addTool({
                    id: 'close',
                    handler: this[this.closeAction].createDelegate(this, [])
                });
            }
        },

        // private
        resizerAction : function(){
            var box = this.proxy.getBox();
            this.proxy.hide();
            this.window.handleResize(box);
            return box;
        },

        // private
        beforeResize : function(){
            this.resizer.minHeight = Math.max(this.minHeight, this.getFrameHeight() + 40); // 40 is a magic minimum content size?
            this.resizer.minWidth = Math.max(this.minWidth, this.getFrameWidth() + 40);
            this.resizeBox = this.el.getBox();
        },

        // private
        updateHandles : function(){
            if(Ext.isIE9m && this.resizer){
                this.resizer.syncHandleHeight();
                this.el.repaint();
            }
        },

        // private
        handleResize : function(box){
            var rz = this.resizeBox;
            if(rz.x != box.x || rz.y != box.y){
                this.updateBox(box);
            }else{
                this.setSize(box);
                if (Ext.isIE6 && Ext.isStrict) {
                    this.doLayout();
                }
            }
            this.focus();
            this.updateHandles();
            this.saveState();
        },

        /**
         * Focuses the window.  If a defaultButton is set, it will receive focus, otherwise the
         * window itself will receive focus.
         */
        focus : function(){
            var f = this.focusEl,
                db = this.defaultButton,
                t = typeof db,
                el,
                ct;
            if(Ext.isDefined(db)){
                if(Ext.isNumber(db) && this.fbar){
                    f = this.fbar.items.get(db);
                }else if(Ext.isString(db)){
                    f = Ext.getCmp(db);
                }else{
                    f = db;
                }
                el = f.getEl();
                ct = Ext.getDom(this.container);
                if (el && ct) {
                    if (ct != document.body && !Ext.lib.Region.getRegion(ct).contains(Ext.lib.Region.getRegion(el.dom))){
                        return;
                    }
                }
            }
            f = f || this.focusEl;
            f.focus.defer(10, f);
        },

        /**
         * Sets the target element from which the window should animate while opening.
         * @param {String/Element} el The target element or id
         */
        setAnimateTarget : function(el){
            el = Ext.get(el);
            this.animateTarget = el;
        },

        // private
        beforeShow : function(){
            delete this.el.lastXY;
            delete this.el.lastLT;
            if(this.x === undefined || this.y === undefined){
                var xy = this.el.getAlignToXY(this.container, 'c-c');
                var pos = this.el.translatePoints(xy[0], xy[1]);
                this.x = this.x === undefined? pos.left : this.x;
                this.y = this.y === undefined? pos.top : this.y;
            }
            this.el.setLeftTop(this.x, this.y);

            if(this.expandOnShow){
                this.expand(false);
            }

            if(this.modal){
                Ext.getBody().addClass('x-body-masked');
                this.mask.setSize(Ext.lib.Dom.getViewWidth(true), Ext.lib.Dom.getViewHeight(true));
                this.mask.show();
            }
        },

        /**
         * Shows the window, rendering it first if necessary, or activates it and brings it to front if hidden.
         * @param {String/Element} animateTarget (optional) The target element or id from which the window should
         * animate while opening (defaults to null with no animation)
         * @param {Function} callback (optional) A callback function to call after the window is displayed
         * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the callback is executed. Defaults to this Window.
         * @return {Ext.Window} this
         */
        show : function(animateTarget, cb, scope){
            if(!this.rendered){
                this.render(Ext.getBody());
            }
            if(this.hidden === false){
                this.toFront();
                return this;
            }
            if(this.fireEvent('beforeshow', this) === false){
                return this;
            }
            if(cb){
                this.on('show', cb, scope, {single:true});
            }
            this.hidden = false;
            if(Ext.isDefined(animateTarget)){
                this.setAnimateTarget(animateTarget);
            }
            this.beforeShow();
            if(this.animateTarget){
                this.animShow();
            }else{
                this.afterShow();
            }
            return this;
        },

        // private
        afterShow : function(isAnim){
            if (this.isDestroyed){
                return false;
            }
            this.proxy.hide();
            this.el.setStyle('display', 'block');
            this.el.show();
            if(this.maximized){
                this.fitContainer();
            }
            if(Ext.isMac && Ext.isGecko2){ // work around stupid FF 2.0/Mac scroll bar bug
                this.cascade(this.setAutoScroll);
            }

            if(this.monitorResize || this.modal || this.constrain || this.constrainHeader){
                Ext.EventManager.onWindowResize(this.onWindowResize, this);
            }
            this.doConstrain();
            this.doLayout();
            if(this.keyMap){
                this.keyMap.enable();
            }
            this.toFront();
            this.updateHandles();
            if(isAnim && (Ext.isIE || Ext.isWebKit)){
                var sz = this.getSize();
                this.onResize(sz.width, sz.height);
            }
            this.onShow();
            this.fireEvent('show', this);
        },

        // private
        animShow : function(){
            this.proxy.show();
            this.proxy.setBox(this.animateTarget.getBox());
            this.proxy.setOpacity(0);
            var b = this.getBox();
            this.el.setStyle('display', 'none');
            this.proxy.shift(Ext.apply(b, {
                callback: this.afterShow.createDelegate(this, [true], false),
                scope: this,
                easing: 'easeNone',
                duration: this.showAnimDuration,
                opacity: 0.5
            }));
        },

        /**
         * Hides the window, setting it to invisible and applying negative offsets.
         * @param {String/Element} animateTarget (optional) The target element or id to which the window should
         * animate while hiding (defaults to null with no animation)
         * @param {Function} callback (optional) A callback function to call after the window is hidden
         * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the callback is executed. Defaults to this Window.
         * @return {Ext.Window} this
         */
        hide : function(animateTarget, cb, scope){
            if(this.hidden || this.fireEvent('beforehide', this) === false){
                return this;
            }
            if(cb){
                this.on('hide', cb, scope, {single:true});
            }
            this.hidden = true;
            if(animateTarget !== undefined){
                this.setAnimateTarget(animateTarget);
            }
            if(this.modal){
                this.mask.hide();
                Ext.getBody().removeClass('x-body-masked');
            }
            if(this.animateTarget){
                this.animHide();
            }else{
                this.el.hide();
                this.afterHide();
            }
            return this;
        },

        // private
        afterHide : function(){
            this.proxy.hide();
            if(this.monitorResize || this.modal || this.constrain || this.constrainHeader){
                Ext.EventManager.removeResizeListener(this.onWindowResize, this);
            }
            if(this.keyMap){
                this.keyMap.disable();
            }
            this.onHide();
            this.fireEvent('hide', this);
        },

        // private
        animHide : function(){
            this.proxy.setOpacity(0.5);
            this.proxy.show();
            var tb = this.getBox(false);
            this.proxy.setBox(tb);
            this.el.hide();
            this.proxy.shift(Ext.apply(this.animateTarget.getBox(), {
                callback: this.afterHide,
                scope: this,
                duration: this.hideAnimDuration,
                easing: 'easeNone',
                opacity: 0
            }));
        },

        /**
         * Method that is called immediately before the <code>show</code> event is fired.
         * Defaults to <code>Ext.emptyFn</code>.
         */
        onShow : Ext.emptyFn,

        /**
         * Method that is called immediately before the <code>hide</code> event is fired.
         * Defaults to <code>Ext.emptyFn</code>.
         */
        onHide : Ext.emptyFn,

        // private
        onWindowResize : function(){
            if(this.maximized){
                this.fitContainer();
            }
            if(this.modal){
                this.mask.setSize('100%', '100%');
                var force = this.mask.dom.offsetHeight;
                this.mask.setSize(Ext.lib.Dom.getViewWidth(true), Ext.lib.Dom.getViewHeight(true));
            }
            this.doConstrain();
        },

        // private
        doConstrain : function(){
            if(this.constrain || this.constrainHeader){
                var offsets;
                if(this.constrain){
                    offsets = {
                        right:this.el.shadowOffset,
                        left:this.el.shadowOffset,
                        bottom:this.el.shadowOffset
                    };
                }else {
                    var s = this.getSize();
                    offsets = {
                        right:-(s.width - 100),
                        bottom:-(s.height - 25 + this.el.getConstrainOffset())
                    };
                }

                var xy = this.el.getConstrainToXY(this.container, true, offsets);
                if(xy){
                    this.setPosition(xy[0], xy[1]);
                }
            }
        },

        // private - used for dragging
        ghost : function(cls){
            var ghost = this.createGhost(cls);
            var box = this.getBox(true);
            ghost.setLeftTop(box.x, box.y);
            ghost.setWidth(box.width);
            this.el.hide();
            this.activeGhost = ghost;
            return ghost;
        },

        // private
        unghost : function(show, matchPosition){
            if(!this.activeGhost) {
                return;
            }
            if(show !== false){
                this.el.show();
                this.focus.defer(10, this);
                if(Ext.isMac && Ext.isGecko2){ // work around stupid FF 2.0/Mac scroll bar bug
                    this.cascade(this.setAutoScroll);
                }
            }
            if(matchPosition !== false){
                this.setPosition(this.activeGhost.getLeft(true), this.activeGhost.getTop(true));
            }
            this.activeGhost.hide();
            this.activeGhost.remove();
            delete this.activeGhost;
        },

        /**
         * Placeholder method for minimizing the window.  By default, this method simply fires the {@link #minimize} event
         * since the behavior of minimizing a window is application-specific.  To implement custom minimize behavior,
         * either the minimize event can be handled or this method can be overridden.
         * @return {Ext.Window} this
         */
        minimize : function(){
            this.fireEvent('minimize', this);
            return this;
        },

        /**
         * <p>Closes the Window, removes it from the DOM, {@link Ext.Component#destroy destroy}s
         * the Window object and all its descendant Components. The {@link Ext.Panel#beforeclose beforeclose}
         * event is fired before the close happens and will cancel the close action if it returns false.<p>
         * <p><b>Note:</b> This method is not affected by the {@link #closeAction} setting which
         * only affects the action triggered when clicking the {@link #closable 'close' tool in the header}.
         * To hide the Window without destroying it, call {@link #hide}.</p>
         */
        close : function(){
            if(this.fireEvent('beforeclose', this) !== false){
                if(this.hidden){
                    this.doClose();
                }else{
                    this.hide(null, this.doClose, this);
                }
            }
        },

        // private
        doClose : function(){
            this.fireEvent('close', this);
            this.destroy();
        },

        /**
         * Fits the window within its current container and automatically replaces
         * the {@link #maximizable 'maximize' tool button} with the 'restore' tool button.
         * Also see {@link #toggleMaximize}.
         * @return {Ext.Window} this
         */
        maximize : function(){
            if(!this.maximized){
                this.expand(false);
                this.restoreSize = this.getSize();
                this.restorePos = this.getPosition(true);
                if (this.maximizable){
                    this.tools.maximize.hide();
                    this.tools.restore.show();
                }
                this.maximized = true;
                this.el.disableShadow();

                if(this.dd){
                    this.dd.lock();
                }
                if(this.collapsible){
                    this.tools.toggle.hide();
                }
                this.el.addClass('x-window-maximized');
                this.container.addClass('x-window-maximized-ct');

                this.setPosition(0, 0);
                this.fitContainer();
                this.fireEvent('maximize', this);
            }
            return this;
        },

        /**
         * Restores a {@link #maximizable maximized}  window back to its original
         * size and position prior to being maximized and also replaces
         * the 'restore' tool button with the 'maximize' tool button.
         * Also see {@link #toggleMaximize}.
         * @return {Ext.Window} this
         */
        restore : function(){
            if(this.maximized){
                var t = this.tools;
                this.el.removeClass('x-window-maximized');
                if(t.restore){
                    t.restore.hide();
                }
                if(t.maximize){
                    t.maximize.show();
                }
                this.setPosition(this.restorePos[0], this.restorePos[1]);
                this.setSize(this.restoreSize.width, this.restoreSize.height);
                delete this.restorePos;
                delete this.restoreSize;
                this.maximized = false;
                this.el.enableShadow(true);

                if(this.dd){
                    this.dd.unlock();
                }
                if(this.collapsible && t.toggle){
                    t.toggle.show();
                }
                this.container.removeClass('x-window-maximized-ct');

                this.doConstrain();
                this.fireEvent('restore', this);
            }
            return this;
        },

        /**
         * A shortcut method for toggling between {@link #maximize} and {@link #restore} based on the current maximized
         * state of the window.
         * @return {Ext.Window} this
         */
        toggleMaximize : function(){
            return this[this.maximized ? 'restore' : 'maximize']();
        },

        // private
        fitContainer : function(){
            var vs = this.container.getViewSize(false);
            this.setSize(vs.width, vs.height);
        },

        // private
        // z-index is managed by the WindowManager and may be overwritten at any time
        setZIndex : function(index){
            if(this.modal){
                this.mask.setStyle('z-index', index);
            }
            this.el.setZIndex(++index);
            index += 5;

            if(this.resizer){
                this.resizer.proxy.setStyle('z-index', ++index);
            }

            this.lastZIndex = index;
        },

        /**
         * Aligns the window to the specified element
         * @param {Mixed} element The element to align to.
         * @param {String} position (optional, defaults to "tl-bl?") The position to align to (see {@link Ext.Element#alignTo} for more details).
         * @param {Array} offsets (optional) Offset the positioning by [x, y]
         * @return {Ext.Window} this
         */
        alignTo : function(element, position, offsets){
            var xy = this.el.getAlignToXY(element, position, offsets);
            this.setPagePosition(xy[0], xy[1]);
            return this;
        },

        /**
         * Anchors this window to another element and realigns it when the window is resized or scrolled.
         * @param {Mixed} element The element to align to.
         * @param {String} position The position to align to (see {@link Ext.Element#alignTo} for more details)
         * @param {Array} offsets (optional) Offset the positioning by [x, y]
         * @param {Boolean/Number} monitorScroll (optional) true to monitor body scroll and reposition. If this parameter
         * is a number, it is used as the buffer delay (defaults to 50ms).
         * @return {Ext.Window} this
         */
        anchorTo : function(el, alignment, offsets, monitorScroll){
            this.clearAnchor();
            this.anchorTarget = {
                el: el,
                alignment: alignment,
                offsets: offsets
            };

            Ext.EventManager.onWindowResize(this.doAnchor, this);
            var tm = typeof monitorScroll;
            if(tm != 'undefined'){
                Ext.EventManager.on(window, 'scroll', this.doAnchor, this,
                    {buffer: tm == 'number' ? monitorScroll : 50});
            }
            return this.doAnchor();
        },

        /**
         * Performs the anchor, using the saved anchorTarget property.
         * @return {Ext.Window} this
         * @private
         */
        doAnchor : function(){
            var o = this.anchorTarget;
            this.alignTo(o.el, o.alignment, o.offsets);
            return this;
        },

        /**
         * Removes any existing anchor from this window. See {@link #anchorTo}.
         * @return {Ext.Window} this
         */
        clearAnchor : function(){
            if(this.anchorTarget){
                Ext.EventManager.removeResizeListener(this.doAnchor, this);
                Ext.EventManager.un(window, 'scroll', this.doAnchor, this);
                delete this.anchorTarget;
            }
            return this;
        },

        /**
         * Brings this window to the front of any other visible windows
         * @param {Boolean} e (optional) Specify <tt>false</tt> to prevent the window from being focused.
         * @return {Ext.Window} this
         */
        toFront : function(e){
            if(this.manager.bringToFront(this)){
                if(!e || !e.getTarget().focus){
                    this.focus();
                }
            }
            return this;
        },

        /**
         * Makes this the active window by showing its shadow, or deactivates it by hiding its shadow.  This method also
         * fires the {@link #activate} or {@link #deactivate} event depending on which action occurred. This method is
         * called internally by {@link Ext.WindowMgr}.
         * @param {Boolean} active True to activate the window, false to deactivate it (defaults to false)
         */
        setActive : function(active){
            if(active){
                if(!this.maximized){
                    this.el.enableShadow(true);
                }
                this.fireEvent('activate', this);
            }else{
                this.el.disableShadow();
                this.fireEvent('deactivate', this);
            }
        },

        /**
         * Sends this window to the back of (lower z-index than) any other visible windows
         * @return {Ext.Window} this
         */
        toBack : function(){
            this.manager.sendToBack(this);
            return this;
        },

        /**
         * Centers this window in the viewport
         * @return {Ext.Window} this
         */
        center : function(){
            var xy = this.el.getAlignToXY(this.container, 'c-c');
            this.setPagePosition(xy[0], xy[1]);
            return this;
        }

        /**
         * @cfg {Boolean} autoWidth @hide
         **/
    });
    Ext.reg('window', Ext.Window);

    // private - custom Window DD implementation
    Ext.Window.DD = Ext.extend(Ext.dd.DD, {

        constructor : function(win){
            this.win = win;
            Ext.Window.DD.superclass.constructor.call(this, win.el.id, 'WindowDD-'+win.id);
            this.setHandleElId(win.header.id);
            this.scroll = false;
        },

        moveOnly:true,
        headerOffsets:[100, 25],
        startDrag : function(){
            var w = this.win;
            this.proxy = w.ghost(w.initialConfig.cls);
            if(w.constrain !== false){
                var so = w.el.shadowOffset;
                this.constrainTo(w.container, {right: so, left: so, bottom: so});
            }else if(w.constrainHeader !== false){
                var s = this.proxy.getSize();
                this.constrainTo(w.container, {right: -(s.width-this.headerOffsets[0]), bottom: -(s.height-this.headerOffsets[1])});
            }
        },
        b4Drag : Ext.emptyFn,

        onDrag : function(e){
            this.alignElWithMouse(this.proxy, e.getPageX(), e.getPageY());
        },

        endDrag : function(e){
            this.win.unghost();
            this.win.saveState();
        }
    });