    /**
     * Panel is a container that has specific functionality and structural components that make it the perfect building
     * block for application-oriented user interfaces.
     *
     * Panels are, by virtue of their inheritance from {@link Ext.container.Container}, capable of being configured with a
     * {@link Ext.container.Container#layout layout}, and containing child Components.
     *
     * When either specifying child {@link #cfg-items} of a Panel, or dynamically {@link Ext.container.Container#method-add adding}
     * Components to a Panel, remember to consider how you wish the Panel to arrange those child elements, and whether those
     * child elements need to be sized using one of Ext's built-in `{@link Ext.container.Container#layout layout}`
     * schemes. By default, Panels use the {@link Ext.layout.container.Auto Auto} scheme. This simply renders child
     * components, appending them one after the other inside the Container, and **does not apply any sizing** at all.
     *
     * {@img Ext.panel.Panel/panel.png Panel components}
     *
     * A Panel may also contain {@link #bbar bottom} and {@link #tbar top} toolbars, along with separate {@link
     * Ext.panel.Header header}, {@link #fbar footer} and body sections.
     *
     * Panel also provides built-in {@link #collapsible collapsible, expandable} and {@link #closable} behavior. Panels can
     * be easily dropped into any {@link Ext.container.Container Container} or layout, and the layout and rendering pipeline
     * is {@link Ext.container.Container#method-add completely managed by the framework}.
     *
     * **Note:** By default, the `{@link #closable close}` header tool _destroys_ the Panel resulting in removal of the
     * Panel and the destruction of any descendant Components. This makes the Panel object, and all its descendants
     * **unusable**. To enable the close tool to simply _hide_ a Panel for later re-use, configure the Panel with
     * `{@link #closeAction closeAction}: 'hide'`.
     *
     * Usually, Panels are used as constituents within an application, in which case, they would be used as child items of
     * Containers, and would themselves use Ext.Components as child {@link #cfg-items}. However to illustrate simply rendering a
     * Panel into the document, here's how to do it:
     *
     *     @example
     *     Ext.create('Ext.panel.Panel', {
     *         title: 'Hello',
     *         width: 200,
     *         html: '<p>World!</p>',
     *         renderTo: Ext.getBody()
     *     });
     *
     * A more realistic scenario is a Panel created to house input fields which will not be rendered, but used as a
     * constituent part of a Container:
     *
     *     @example
     *     var filterPanel = Ext.create('Ext.panel.Panel', {
     *         bodyPadding: 5,  // Don't want content to crunch against the borders
     *         width: 300,
     *         title: 'Filters',
     *         items: [{
     *             xtype: 'datefield',
     *             fieldLabel: 'Start date'
     *         }, {
     *             xtype: 'datefield',
     *             fieldLabel: 'End date'
     *         }],
     *         renderTo: Ext.getBody()
     *     });
     *
     * Note that the Panel above is configured to render into the document and assigned a size. In a real world scenario,
     * the Panel will often be added inside a Container which will use a {@link #layout} to render, size and position its
     * child Components.
     *
     * Panels will often use specific {@link #layout}s to provide an application with shape and structure by containing and
     * arranging child Components:
     *
     *     @example
     *     var resultsPanel = Ext.create('Ext.panel.Panel', {
     *         title: 'Results',
     *         width: 600,
     *         height: 400,
     *         renderTo: Ext.getBody(),
     *         layout: {
     *             type: 'vbox',       // Arrange child items vertically
     *             align: 'stretch',    // Each takes up full width
     *             padding: 5
     *         },
     *         items: [{               // Results grid specified as a config object with an xtype of 'grid'
     *             xtype: 'grid',
     *             columns: [{header: 'Column One'}],            // One header just for show. There's no data,
     *             store: Ext.create('Ext.data.ArrayStore', {}), // A dummy empty data store
     *             flex: 1                                       // Use 1/3 of Container's height (hint to Box layout)
     *         }, {
     *             xtype: 'splitter'   // A splitter between the two child items
     *         }, {                    // Details Panel specified as a config object (no xtype defaults to 'panel').
     *             title: 'Details',
     *             bodyPadding: 5,
     *             items: [{
     *                 fieldLabel: 'Data item',
     *                 xtype: 'textfield'
     *             }], // An array of form fields
     *             flex: 2             // Use 2/3 of Container's height (hint to Box layout)
     *         }]
     *     });
     *
     * The example illustrates one possible method of displaying search results. The Panel contains a grid with the
     * resulting data arranged in rows. Each selected row may be displayed in detail in the Panel below. The {@link
     * Ext.layout.container.VBox vbox} layout is used to arrange the two vertically. It is configured to stretch child items
     * horizontally to full width. Child items may either be configured with a numeric height, or with a `flex` value to
     * distribute available space proportionately.
     *
     * This Panel itself may be a child item of, for exaple, a {@link Ext.tab.Panel} which will size its child items to fit
     * within its content area.
     *
     * Using these techniques, as long as the **layout** is chosen and configured correctly, an application may have any
     * level of nested containment, all dynamically sized according to configuration, the user's preference and available
     * browser size.
     */
    Ext.define('Ext.panel.Panel', {
        extend: 'Ext.panel.AbstractPanel',
        requires: [
            'Ext.panel.Header',
            'Ext.fx.Anim',
            'Ext.util.KeyMap',
            'Ext.panel.DD',
            'Ext.XTemplate',
            'Ext.layout.component.Dock',
            'Ext.util.Memento'
        ],
        alias: 'widget.panel',
        alternateClassName: 'Ext.Panel',

        /**
         * @cfg {String} collapsedCls
         * A CSS class to add to the panel's element after it has been collapsed.
         */
        collapsedCls: 'collapsed',

        /**
         * @cfg {Boolean} animCollapse
         * `true` to animate the transition when the panel is collapsed, `false` to skip the animation (defaults to `true`
         * if the {@link Ext.fx.Anim} class is available, otherwise `false`). May also be specified as the animation
         * duration in milliseconds.
         */
        animCollapse: Ext.enableFx,

        /**
         * @cfg {Number} minButtonWidth
         * Minimum width of all footer toolbar buttons in pixels. If set, this will be used as the default
         * value for the {@link Ext.button.Button#minWidth} config of each Button added to the **footer toolbar** via the
         * {@link #fbar} or {@link #buttons} configurations. It will be ignored for buttons that have a minWidth configured
         * some other way, e.g. in their own config object or via the {@link Ext.container.Container#defaults defaults} of
         * their parent container.
         */
        minButtonWidth: 75,

        /**
         * @cfg {Boolean} collapsed
         * `true` to render the panel collapsed, `false` to render it expanded.
         */
        collapsed: false,

        /**
         * @cfg {Boolean} collapseFirst
         * `true` to make sure the collapse/expand toggle button always renders first (to the left of) any other tools in
         * the panel's title bar, `false` to render it last.
         */
        collapseFirst: true,

        /**
         * @cfg {Boolean} hideCollapseTool
         * `true` to hide the expand/collapse toggle button when `{@link #collapsible} == true`, `false` to display it.
         */
        hideCollapseTool: false,

        /**
         * @cfg {Boolean} titleCollapse
         * `true` to allow expanding and collapsing the panel (when `{@link #collapsible} = true`) by clicking anywhere in
         * the header bar, `false`) to allow it only by clicking to tool button).
         */
        titleCollapse: false,

        /**
         * @cfg {String} collapseMode
         * **Important: this config is only effective for {@link #collapsible} Panels which are direct child items of a
         * {@link Ext.layout.container.Border border layout}.**
         *
         * When _not_ a direct child item of a {@link Ext.layout.container.Border border layout}, then the Panel's header
         * remains visible, and the body is collapsed to zero dimensions. If the Panel has no header, then a new header
         * (orientated correctly depending on the {@link #collapseDirection}) will be inserted to show a the title and a re-
         * expand tool.
         *
         * When a child item of a {@link Ext.layout.container.Border border layout}, this config has three possible values:
         *
         * - `undefined` - When collapsed, a placeholder {@link Ext.panel.Header Header} is injected into the layout to
         *   represent the Panel and to provide a UI with a Tool to allow the user to re-expand the Panel.
         *
         * - `"header"` - The Panel collapses to leave its header visible as when not inside a
         *   {@link Ext.layout.container.Border border layout}.
         *
         * - `"mini"` - The Panel collapses without a visible header.
         */

        /**
         * @cfg {Ext.Component/Object} placeholder
         * **Important: This config is only effective for {@link #collapsible} Panels which are direct child items of a
         * {@link Ext.layout.container.Border border layout} when not using the `'header'` {@link #collapseMode}.**
         *
         * **Optional.** A Component (or config object for a Component) to show in place of this Panel when this Panel is
         * collapsed by a {@link Ext.layout.container.Border border layout}. Defaults to a generated {@link Ext.panel.Header
         * Header} containing a {@link Ext.panel.Tool Tool} to re-expand the Panel.
         */

        /**
         * @cfg {Boolean} floatable
         * **Important: This config is only effective for {@link #collapsible} Panels which are direct child items of a
         * {@link Ext.layout.container.Border border layout}.**
         *
         * true to allow clicking a collapsed Panel's {@link #placeholder} to display the Panel floated above the layout,
         * false to force the user to fully expand a collapsed region by clicking the expand button to see it again.
         */
        floatable: true,

        /**
         * @cfg {Boolean} overlapHeader
         * True to overlap the header in a panel over the framing of the panel itself. This is needed when frame:true (and
         * is done automatically for you). Otherwise it is undefined. If you manually add rounded corners to a panel header
         * which does not have frame:true, this will need to be set to true.
         */

        /**
         * @cfg {Boolean} collapsible
         * True to make the panel collapsible and have an expand/collapse toggle Tool added into the header tool button
         * area. False to keep the panel sized either statically, or by an owning layout manager, with no toggle Tool.
         *
         * See {@link #collapseMode} and {@link #collapseDirection}
         */
        collapsible: false,

        /**
         * @cfg {String} collapseDirection
         * The direction to collapse the Panel when the toggle button is clicked.
         *
         * Defaults to the {@link #headerPosition}
         *
         * **Important: This config is _ignored_ for {@link #collapsible} Panels which are direct child items of a {@link
         * Ext.layout.container.Border border layout}.**
         *
         * Specify as `'top'`, `'bottom'`, `'left'` or `'right'`.
         */

        /**
         * @cfg {Boolean} closable
         * 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.
         *
         * By default, when close is requested by clicking the close button in the header, the {@link #method-close} method will be
         * called. This will _{@link Ext.Component#method-destroy destroy}_ the Panel and its content meaning that it may not be
         * reused.
         *
         * To make closing a Panel _hide_ the Panel so that it may be reused, set {@link #closeAction} to 'hide'.
         */
        closable: false,

        /**
         * @cfg {String} closeAction
         * The action to take when the close header tool is clicked:
         *
         * - **`'{@link #method-destroy}'`** :
         *
         *   {@link #method-remove remove} the window from the DOM and {@link Ext.Component#method-destroy destroy} it and all descendant
         *   Components. The window will **not** be available to be redisplayed via the {@link #method-show} method.
         *
         * - **`'{@link #method-hide}'`** :
         *
         *   {@link #method-hide} the window by setting visibility to hidden and applying negative offsets. The window will be
         *   available to be redisplayed via the {@link #method-show} method.
         *
         * **Note:** This behavior has changed! setting *does* affect the {@link #method-close} method which will invoke the
         * approriate closeAction.
         */
        closeAction: 'destroy',

        /**
         * @cfg {Object/Object[]} dockedItems
         * A component or series of components to be added as docked items to this panel. The docked items can be docked to
         * either the top, right, left or bottom of a panel. This is typically used for things like toolbars or tab bars:
         *
         *     var panel = new Ext.panel.Panel({
         *         dockedItems: [{
         *             xtype: 'toolbar',
         *             dock: 'top',
         *             items: [{
         *                 text: 'Docked to the top'
         *             }]
         *         }]
         *     });
         */

        /**
         * @cfg {Number} placeholderCollapseHideMode
         * The {@link Ext.dom.Element#setVisibilityMode mode} for hiding collapsed panels when
         * using {@link #collapseMode} "placeholder".
         */
        placeholderCollapseHideMode: Ext.Element.VISIBILITY,

        /**
         * @cfg {Boolean} preventHeader
         * @deprecated 4.1.0 Use {@link #header} instead.
         * Prevent a Header from being created and shown.
         */
         preventHeader: false,

        /**
         * @cfg {Boolean/Object} header
         * Pass as `false` to prevent a Header from being created and shown.
         *
         * Pass as a config object (optionally containing an `xtype`) to custom-configure this Panel's header.
         *
         */
        header: undefined,

        /**
         * @cfg {String} headerPosition
         * Specify as `'top'`, `'bottom'`, `'left'` or `'right'`.
         */
        headerPosition: 'top',

        /**
         * @cfg {Boolean} frame
         * True to apply a frame to the panel.
         */
        frame: false,

        /**
         * @cfg {Boolean} frameHeader
         * True to apply a frame to the panel panels header (if 'frame' is true).
         */
        frameHeader: true,

        /**
         * @cfg {Object[]/Ext.panel.Tool[]} tools
         * An array of {@link Ext.panel.Tool} configs/instances to be added to the header tool area. The tools are stored as
         * child components of the header container. They can be accessed using {@link #down} and {#query}, as well as the
         * other component methods. The toggle tool is automatically created if {@link #collapsible} is set to true.
         *
         * Note that, apart from the toggle tool which is provided when a panel is collapsible, these tools only provide the
         * visual button. Any required functionality must be provided by adding handlers that implement the necessary
         * behavior.
         *
         * Example usage:
         *
         *     tools:[{
         *         type:'refresh',
         *         tooltip: 'Refresh form Data',
         *         // hidden:true,
         *         handler: function(event, toolEl, panel){
         *             // refresh logic
         *         }
         *     },
         *     {
         *         type:'help',
         *         tooltip: 'Get Help',
         *         handler: function(event, toolEl, panel){
         *             // show help here
         *         }
         *     }]
         */

        /**
         * @cfg {String} [title='']
         * The title text to be used to display in the {@link Ext.panel.Header panel header}. When a
         * `title` is specified the {@link Ext.panel.Header} will automatically be created and displayed unless
         * {@link #header} is set to `false`.
         */

        /**
         * @cfg {String} [titleAlign='left']
         * May be `"left"`, `"right"` or `"center"`.
         *
         * The alignment of the title text within the available space between the icon and the tools.
         */
        titleAlign: 'left',

        /**
         * @cfg {Boolean} [manageHeight=true]: When true, the dock component layout writes
         * height information to the panel's DOM elements based on its shrink wrap height
         * calculation. This ensures that the browser respects the calculated height.
         * When false, the dock component layout will not write heights on the panel or its
         * body element. In some simple layout cases, not writing the heights to the DOM may
         * be desired because this allows the browser to respond to direct DOM manipulations
         * (like animations).
         */
        manageHeight: true,

        /**
         * @cfg {String} iconCls
         * CSS class for an icon in the header. Used for displaying an icon to the left of a title.
         */

        /**
         * @cfg {String} icon
         * Path to image for an icon in the header. Used for displaying an icon to the left of a title.
         */

        initComponent: function() {
            var me = this;

            me.addEvents(

                /**
                 * @event beforeclose
                 * Fires before the user closes the panel. Return false from any listener to stop the close event being
                 * fired
                 * @param {Ext.panel.Panel} panel The Panel object
                 */
                'beforeclose',

                /**
                 * @event close
                 * Fires when the user closes the panel.
                 * @param {Ext.panel.Panel} panel The Panel object
                 */
                'close',

                /**
                 * @event beforeexpand
                 * Fires before this panel is expanded. Return false to prevent the expand.
                 * @param {Ext.panel.Panel} p The Panel being expanded.
                 * @param {Boolean} animate True if the expand is animated, else false.
                 */
                "beforeexpand",

                /**
                 * @event beforecollapse
                 * Fires before this panel is collapsed. Return false to prevent the collapse.
                 * @param {Ext.panel.Panel} p The Panel being collapsed.
                 * @param {String} direction . The direction of the collapse. One of
                 *
                 *   - Ext.Component.DIRECTION_TOP
                 *   - Ext.Component.DIRECTION_RIGHT
                 *   - Ext.Component.DIRECTION_BOTTOM
                 *   - Ext.Component.DIRECTION_LEFT
                 *
                 * @param {Boolean} animate True if the collapse is animated, else false.
                 */
                "beforecollapse",

                /**
                 * @event expand
                 * Fires after this Panel has expanded.
                 * @param {Ext.panel.Panel} p The Panel that has been expanded.
                 */
                "expand",

                /**
                 * @event collapse
                 * Fires after this Panel hass collapsed.
                 * @param {Ext.panel.Panel} p The Panel that has been collapsed.
                 */
                "collapse",

                /**
                 * @event titlechange
                 * Fires after the Panel title has been set or changed.
                 * @param {Ext.panel.Panel} p the Panel which has been resized.
                 * @param {String} newTitle The new title.
                 * @param {String} oldTitle The previous panel title.
                 */
                'titlechange',

                /**
                 * @event iconchange
                 * Fires after the Panel icon has been set or changed.
                 * @param {Ext.panel.Panel} p The Panel which has the icon changed.
                 * @param {String} newIcon The path to the new icon image.
                 * @param {String} oldIcon The path to the previous panel icon image.
                 */
                'iconchange',

                /**
                 * @event iconclschange
                 * Fires after the Panel iconCls has been set or changed.
                 * @param {Ext.panel.Panel} p The Panel which has the iconCls changed.
                 * @param {String} newIconCls The new iconCls.
                 * @param {String} oldIconCls The previous panel iconCls.
                 */
                'iconclschange'
            );

            if (me.collapsible) {
            // Save state on these two events.
                this.addStateEvents(['expand', 'collapse']);
            }
            if (me.unstyled) {
                me.setUI('plain');
            }

            if (me.frame) {
                me.setUI(me.ui + '-framed');
            }

            // Backwards compatibility
            me.bridgeToolbars();

            me.callParent();
            me.collapseDirection = me.collapseDirection || me.headerPosition || Ext.Component.DIRECTION_TOP;

            // Used to track hidden content elements during collapsed state
            me.hiddenOnCollapse = new Ext.dom.CompositeElement();

        },

        beforeDestroy: function() {
            var me = this;
            Ext.destroy(
                me.placeholder,
                me.ghostPanel,
                me.dd
            );
            me.callParent();
        },

        initAria: function() {
            this.callParent();
            this.initHeaderAria();
        },

        getFocusEl: function() {
            return  this.el;
        },

        initHeaderAria: function() {
            var me = this,
                el = me.el,
                header = me.header;
            if (el && header) {
                el.dom.setAttribute('aria-labelledby', header.titleCmp.id);
            }
        },

        /**
         * Gets the {@link Ext.panel.Header Header} for this panel.
         */
        getHeader: function() {
            return this.header;
        },

        /**
         * Set a title for the panel's header. See {@link Ext.panel.Header#title}.
         * @param {String} newTitle
         */
        setTitle: function(newTitle) {
            var me = this,
                oldTitle = me.title,
                header = me.header,
                reExpander = me.reExpander,
                placeholder = me.placeholder;

            me.title = newTitle;

            if (header) {
                if (header.isHeader) {
                    header.setTitle(newTitle);
                } else {
                    header.title = newTitle;
                }
            } else {
                me.updateHeader();
            }

            if (reExpander) {
                reExpander.setTitle(newTitle);
            }

            if (placeholder && placeholder.setTitle) {
                placeholder.setTitle(newTitle);
            }

            me.fireEvent('titlechange', me, newTitle, oldTitle);
        },

        /**
         * Set the iconCls for the panel's header. See {@link Ext.panel.Header#iconCls}. It will fire the
         * {@link #iconclschange} event after completion.
         * @param {String} newIconCls The new CSS class name
         */
        setIconCls: function(newIconCls) {
            var me = this,
                oldIconCls = me.iconCls,
                header = me.header,
                placeholder = me.placeholder;

            me.iconCls = newIconCls;

            if (header) {
                if (header.isHeader) {
                    header.setIconCls(newIconCls);
                } else {
                    header.iconCls = newIconCls;
                }
            } else {
                me.updateHeader();
            }

            if (placeholder && placeholder.setIconCls) {
                placeholder.setIconCls(newIconCls);
            }

            me.fireEvent('iconclschange', me, newIconCls, oldIconCls);
        },

        /**
         * Set the icon for the panel's header. See {@link Ext.panel.Header#icon}. It will fire the
         * {@link #iconchange} event after completion.
         * @param {String} newIcon The new icon path
         */
        setIcon: function(newIcon) {
            var me = this,
                oldIcon = me.icon,
                header = me.header,
                placeholder = me.placeholder;

            me.icon = newIcon;

            if (header) {
                if (header.isHeader) {
                    header.setIcon(newIcon);
                } else {
                    header.icon = newIcon;
                }
            } else {
                me.updateHeader();
            }

            if (placeholder && placeholder.setIcon) {
                placeholder.setIcon(newIcon);
            }

            me.fireEvent('iconchange', me, newIcon, oldIcon);
        },

        bridgeToolbars: function() {
            var me = this,
                docked = [],
                fbar,
                fbarDefaults,
                minButtonWidth = me.minButtonWidth;

            function initToolbar (toolbar, pos, useButtonAlign) {
                if (Ext.isArray(toolbar)) {
                    toolbar = {
                        xtype: 'toolbar',
                        items: toolbar
                    };
                }
                else if (!toolbar.xtype) {
                    toolbar.xtype = 'toolbar';
                }
                toolbar.dock = pos;
                if (pos == 'left' || pos == 'right') {
                    toolbar.vertical = true;
                }

                // Legacy support for buttonAlign (only used by buttons/fbar)
                if (useButtonAlign) {
                    toolbar.layout = Ext.applyIf(toolbar.layout || {}, {
                        // default to 'end' (right-aligned) if me.buttonAlign is undefined or invalid
                        pack: { left:'start', center:'center' }[me.buttonAlign] || 'end'
                    });
                }
                return toolbar;
            }

            // Short-hand toolbars (tbar, bbar and fbar plus new lbar and rbar):

            /**
             * @cfg {String} buttonAlign
             * The alignment of any buttons added to this panel. Valid values are 'right', 'left' and 'center' (defaults to
             * 'right' for buttons/fbar, 'left' for other toolbar types).
             *
             * **NOTE:** The prefered way to specify toolbars is to use the dockedItems config. Instead of buttonAlign you
             * would add the layout: { pack: 'start' | 'center' | 'end' } option to the dockedItem config.
             */

            /**
             * @cfg {Object/Object[]} tbar
             * Convenience config. Short for 'Top Bar'.
             *
             *     tbar: [
             *       { xtype: 'button', text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'top',
             *         items: [
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             */
            if (me.tbar) {
                docked.push(initToolbar(me.tbar, 'top'));
                me.tbar = null;
            }

            /**
             * @cfg {Object/Object[]} bbar
             * Convenience config. Short for 'Bottom Bar'.
             *
             *     bbar: [
             *       { xtype: 'button', text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'bottom',
             *         items: [
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             */
            if (me.bbar) {
                docked.push(initToolbar(me.bbar, 'bottom'));
                me.bbar = null;
            }

            /**
             * @cfg {Object/Object[]} buttons
             * Convenience config used for adding buttons docked to the bottom of the panel. This is a
             * synonym for the {@link #fbar} config.
             *
             *     buttons: [
             *       { text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'bottom',
             *         ui: 'footer',
             *         defaults: {minWidth: {@link #minButtonWidth}},
             *         items: [
             *             { xtype: 'component', flex: 1 },
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             *
             * The {@link #minButtonWidth} is used as the default {@link Ext.button.Button#minWidth minWidth} for
             * each of the buttons in the buttons toolbar.
             */
            if (me.buttons) {
                me.fbar = me.buttons;
                me.buttons = null;
            }

            /**
             * @cfg {Object/Object[]} fbar
             * Convenience config used for adding items to the bottom of the panel. Short for Footer Bar.
             *
             *     fbar: [
             *       { type: 'button', text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'bottom',
             *         ui: 'footer',
             *         defaults: {minWidth: {@link #minButtonWidth}},
             *         items: [
             *             { xtype: 'component', flex: 1 },
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             *
             * The {@link #minButtonWidth} is used as the default {@link Ext.button.Button#minWidth minWidth} for
             * each of the buttons in the fbar.
             */
            if (me.fbar) {
                fbar = initToolbar(me.fbar, 'bottom', true); // only we useButtonAlign
                fbar.ui = 'footer';

                // Apply the minButtonWidth config to buttons in the toolbar
                if (minButtonWidth) {
                    fbarDefaults = fbar.defaults;
                    fbar.defaults = function(config) {
                        var defaults = fbarDefaults || {};
                        if ((!config.xtype || config.xtype === 'button' || (config.isComponent && config.isXType('button'))) &&
                                !('minWidth' in defaults)) {
                            defaults = Ext.apply({minWidth: minButtonWidth}, defaults);
                        }
                        return defaults;
                    };
                }

                docked.push(fbar);
                me.fbar = null;
            }

            /**
             * @cfg {Object/Object[]} lbar
             * Convenience config. Short for 'Left Bar' (left-docked, vertical toolbar).
             *
             *     lbar: [
             *       { xtype: 'button', text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'left',
             *         items: [
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             */
            if (me.lbar) {
                docked.push(initToolbar(me.lbar, 'left'));
                me.lbar = null;
            }

            /**
             * @cfg {Object/Object[]} rbar
             * Convenience config. Short for 'Right Bar' (right-docked, vertical toolbar).
             *
             *     rbar: [
             *       { xtype: 'button', text: 'Button 1' }
             *     ]
             *
             * is equivalent to
             *
             *     dockedItems: [{
             *         xtype: 'toolbar',
             *         dock: 'right',
             *         items: [
             *             { xtype: 'button', text: 'Button 1' }
             *         ]
             *     }]
             */
            if (me.rbar) {
                docked.push(initToolbar(me.rbar, 'right'));
                me.rbar = null;
            }

            if (me.dockedItems) {
                if (!Ext.isArray(me.dockedItems)) {
                    me.dockedItems = [me.dockedItems];
                }
                me.dockedItems = me.dockedItems.concat(docked);
            } else {
                me.dockedItems = docked;
            }
        },

        isPlaceHolderCollapse: function(){
            return this.collapseMode == 'placeholder';
        },

        onBoxReady: function(){
            this.callParent();
            if (this.collapsed) {
                this.setHiddenDocked();
            }
        },

        beforeRender: function() {
            var me = this,
                wasCollapsed;

            me.callParent();

            // Add class-specific header tools.
            // Panel adds collapsible and closable.
            me.initTools();

            // Dock the header/title unless we are configured specifically not to create a header
            if (!(me.preventHeader || (me.header === false))) {
                me.updateHeader();
            }

            // If we are rendering collapsed, we still need to save and modify various configs
            if (me.collapsed) {
                if (me.isPlaceHolderCollapse()) {
                    me.hidden = true;

                    // This will insert the placeholder Component into the ownerCt's child collection
                    // Its getRenderTree call which is calling this will then iterate again and
                    // recreate the child items array to include the new Component.
                    me.placeholderCollapse();
                    wasCollapsed = me.collapsed;

                    // Temporarily clear the flag so that the header is rendered with a collapse tool in it.
                    // Placeholder collapse panels never really collapse, they just hide. The tool is always
                    // a collapse tool.
                    me.collapsed = false;
                } else {
                    me.beginCollapse();
                    me.addClsWithUI(me.collapsedCls);
                }
            }

            // Restore the flag if we are being rendered initially placeholder collapsed.
            if (wasCollapsed) {
                me.collapsed = wasCollapsed;
            }
        },

        /**
         * @private
         * Tools are a Panel-specific capabilty.
         * Panel uses initTools. Subclasses may contribute tools by implementing addTools.
         */
        initTools: function() {
            var me = this;

            me.tools = me.tools ? Ext.Array.clone(me.tools) : [];

            // Add a collapse tool unless configured to not show a collapse tool
            // or to not even show a header.
            if (me.collapsible && !(me.hideCollapseTool || me.header === false || me.preventHeader)) {
                me.collapseDirection = me.collapseDirection || me.headerPosition || 'top';
                me.collapseTool = me.expandTool = Ext.widget({
                    xtype: 'tool',
                    type: (me.collapsed && !me.isPlaceHolderCollapse()) ? ('expand-' + me.getOppositeDirection(me.collapseDirection)) : ('collapse-' + me.collapseDirection),
                    handler: me.toggleCollapse,
                    scope: me
                });

                // Prepend collapse tool is configured to do so.
                if (me.collapseFirst) {
                    me.tools.unshift(me.collapseTool);
                }
            }

            // Add subclass-specific tools.
            me.addTools();

            // Make Panel closable.
            if (me.closable) {
                me.addClsWithUI('closable');
                me.addTool({
                    type: 'close',
                    handler: Ext.Function.bind(me.close, me, [])
                });
            }

            // Append collapse tool if needed.
            if (me.collapseTool && !me.collapseFirst) {
                me.addTool(me.collapseTool);
            }
        },

        /**
         * @private
         * @template
         * Template method to be implemented in subclasses to add their tools after the collapsible tool.
         */
        addTools: Ext.emptyFn,

        /**
         * Closes the Panel. By default, this method, removes it from the DOM, {@link Ext.Component#method-destroy destroy}s the
         * Panel object and all its descendant Components. The {@link #beforeclose beforeclose} event is fired before the
         * close happens and will cancel the close action if it returns false.
         *
         * **Note:** This method is also affected by the {@link #closeAction} setting. For more explicit control use
         * {@link #method-destroy} and {@link #method-hide} methods.
         */
        close: function() {
            if (this.fireEvent('beforeclose', this) !== false) {
                this.doClose();
            }
        },

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

        /**
         * Create, hide, or show the header component as appropriate based on the current config.
         * @private
         * @param {Boolean} force True to force the header to be created
         */
        updateHeader: function(force) {
            var me = this,
                header = me.header,
                title = me.title,
                tools = me.tools,
                icon = me.icon || me.iconCls,
                vertical = me.headerPosition == 'left' || me.headerPosition == 'right';

            if ((header !== false) && (force || (title || icon) || (tools && tools.length) || (me.collapsible && !me.titleCollapse))) {
                if (header && header.isHeader) {
                    header.show();
                } else {
                    // Apply the header property to the header config
                    header = me.header = Ext.widget(Ext.apply({
                        xtype       : 'header',
                        title       : title,
                        titleAlign  : me.titleAlign,
                        orientation : vertical ? 'vertical' : 'horizontal',
                        dock        : me.headerPosition || 'top',
                        textCls     : me.headerTextCls,
                        iconCls     : me.iconCls,
                        icon        : me.icon,
                        baseCls     : me.baseCls + '-header',
                        tools       : tools,
                        ui          : me.ui,
                        id          : me.id + '_header',
                        indicateDrag: me.draggable,
                        frame       : (me.frame || me.alwaysFramed) && me.frameHeader,
                        ignoreParentFrame : me.frame || me.overlapHeader,
                        ignoreBorderManagement: me.frame || me.ignoreHeaderBorderManagement,
                        listeners   : me.collapsible && me.titleCollapse ? {
                            click: me.toggleCollapse,
                            scope: me
                        } : null
                    }, me.header));
                    me.addDocked(header, 0);

                    // Reference the Header's tool array.
                    // Header injects named references.
                    me.tools = header.tools;
                }
                me.initHeaderAria();
            } else if (header) {
                header.hide();
            }
        },

        // inherit docs
        setUI: function(ui) {
            var me = this;

            me.callParent(arguments);

            if (me.header && me.header.rendered) {
                me.header.setUI(ui);
            }
        },

        // private
        getContentTarget: function() {
            return this.body;
        },

        getTargetEl: function() {
            var me = this;
            return me.body || me.protoBody || me.frameBody || me.el;
        },

        // the overrides below allow for collapsed regions inside the border layout to be hidden

        // inherit docs
        isVisible: function(deep){
            var me = this;
            if (me.collapsed && me.placeholder) {
                return me.placeholder.isVisible(deep);
            }
            return me.callParent(arguments);
        },

        // inherit docs
        onHide: function(){
            var me = this;
            if (me.collapsed && me.placeholder) {
                me.placeholder.hide();
            } else {
                me.callParent(arguments);
            }
        },

        // inherit docs
        onShow: function(){
            var me = this;
            if (me.collapsed && me.placeholder) {
                // force hidden back to true, since this gets set by the layout
                me.hidden = true;
                me.placeholder.show();
            } else {
                me.callParent(arguments);
            }
        },

        onRemoved: function(destroying) {
            var me = this;

            me.callParent(arguments);

            // If we are removed but not being destroyed, ensure our placeholder is also removed but not destroyed
            // If we are being destroyed, our destroy processing will destroy the placeholder.
            if (me.placeholder && !destroying) {
                me.ownerCt.remove(me.placeholder, false);
            }
        },

        addTool: function(tools) {
            tools = [].concat(tools);

            var me     = this,
                header = me.header,
                t,
                tLen   = tools.length,
                tool;

            for (t = 0; t < tLen; t++) {
                tool = tools[t];

                me.tools.push(tool);

                if (header && header.isHeader) {
                    header.addTool(tool);
                }
            }

            me.updateHeader();
        },

        getOppositeDirection: function(d) {
            var c = Ext.Component;
            switch (d) {
                case c.DIRECTION_TOP:
                    return c.DIRECTION_BOTTOM;
                case c.DIRECTION_RIGHT:
                    return c.DIRECTION_LEFT;
                case c.DIRECTION_BOTTOM:
                    return c.DIRECTION_TOP;
                case c.DIRECTION_LEFT:
                    return c.DIRECTION_RIGHT;
            }
        },

        getWidthAuthority: function() {
            if (this.collapsed && this.collapsedHorizontal()) {
                return 1; // the panel determine's its own width
            }

            return this.callParent();
        },

        getHeightAuthority: function() {
            if (this.collapsed && this.collapsedVertical()) {
                return 1; // the panel determine's its own height
            }

            return this.callParent();
        },

        collapsedHorizontal: function () {
            var dir = this.getCollapsed();
            return dir == 'left' || dir == 'right';
        },

        collapsedVertical: function () {
            var dir = this.getCollapsed();
            return dir == 'top' || dir == 'bottom';
        },

        restoreDimension: function(){
            var dir = this.collapseDirection;
            // If we're collapsing top/bottom, we want to restore the height
            // If we're collapsing left/right, we want to restore the width
            return (dir === 'top' || dir === 'bottom') ? 'height' : 'width';
        },

        /**
         * Returns the current collapsed state of the panel.
         * @return {Boolean/String} False when not collapsed, otherwise the value of {@link #collapseDirection}.
         */
        getCollapsed: function() {
            var me = this;
            // The collapsed flag, when the Panel is collapsed acts as the direction in which the collapse took
            // place. It can still be tested as truthy/falsy if only a truth value is required.
            if (me.collapsed === true) {
                return me.collapseDirection;
            }
            return me.collapsed;
        },

        getState: function() {
            var me = this,
                state = me.callParent(),
                memento;

            state = me.addPropertyToState(state, 'collapsed');

            // If a collapse has taken place, use remembered values as the dimensions.
            if (me.collapsed) {
                memento = me.collapseMemento;
                memento = memento && memento.data;

                if (me.collapsedVertical()) {
                    if (state) {
                        delete state.height;
                    }
                    if (memento) {
                        state = me.addPropertyToState(state, 'height', memento.height);
                    }
                } else {
                    if (state) {
                        delete state.width;
                    }
                    if (memento) {
                        state = me.addPropertyToState(state, 'width', memento.width);
                    }
                }
            }

            return state;
        },

        findReExpander: function (direction) {
            var me = this,
                c = Ext.Component,
                dockedItems = me.dockedItems.items,
                dockedItemCount = dockedItems.length,
                comp, i;

            // never use the header if we're in collapseMode mini
            if (me.collapseMode == 'mini') {
                return;
            }

            switch (direction) {
                case c.DIRECTION_TOP:
                case c.DIRECTION_BOTTOM:

                    // Attempt to find a reExpander Component (docked in a horizontal orientation)
                    // Also, collect all other docked items which we must hide after collapse.
                    for (i = 0; i < dockedItemCount; i++) {
                        comp = dockedItems[i];
                        if (!comp.hidden) {
                            if (comp.isHeader && (!comp.dock || comp.dock == 'top' || comp.dock == 'bottom')) {
                                return comp;
                            }
                        }
                    }
                    break;

                case c.DIRECTION_LEFT:
                case c.DIRECTION_RIGHT:

                    // Attempt to find a reExpander Component (docked in a vecrtical orientation)
                    // Also, collect all other docked items which we must hide after collapse.
                    for (i = 0; i < dockedItemCount; i++) {
                        comp = dockedItems[i];
                        if (!comp.hidden) {
                            if (comp.isHeader && (comp.dock == 'left' || comp.dock == 'right')) {
                                return comp;
                            }
                        }
                    }
                    break;

                default:
                    throw('Panel#findReExpander must be passed a valid collapseDirection');
            }
        },

        getReExpander: function (direction) {
            var me = this,
                collapseDir = direction || me.collapseDirection,
                reExpander = me.reExpander || me.findReExpander(collapseDir);

            me.expandDirection = me.getOppositeDirection(collapseDir);

            if (!reExpander) {
            // We did not find a Header of the required orientation: create one.
                me.reExpander = reExpander = me.createReExpander(collapseDir, {
                    dock: collapseDir,
                    cls: Ext.baseCSSPrefix + 'docked ' + me.baseCls + '-' + me.ui + '-collapsed',
                    ownerCt: me,
                    ownerLayout: me.componentLayout
                });

                me.dockedItems.insert(0, reExpander);
            }
            return reExpander;
        },

        createReExpander: function(direction, defaults) {
            var me = this,
                isLeft = direction == 'left',
                isRight = direction == 'right',
                isVertical = isLeft || isRight,
                toolAtTop,
                result = Ext.apply({
                    hideMode: 'offsets',
                    title: me.title,
                    orientation: isVertical ? 'vertical' : 'horizontal',
                    textCls: me.headerTextCls,
                    icon: me.icon,
                    iconCls: me.iconCls,
                    baseCls: me.baseCls + '-header',
                    ui: me.ui,
                    frame: me.frame && me.frameHeader,
                    ignoreParentFrame: me.frame || me.overlapHeader,
                    indicateDrag: me.draggable
                }, defaults);

                // If we're in mini mode, set the placeholder size to only 1px since
                // we don't need it to show up.
                if (me.collapseMode == 'mini') {
                    if (isVertical) {
                        result.width = 1;
                    } else {
                        result.height = 1;
                    }
                }

            // Create the re expand tool
            // For UI consistency reasons, collapse:left reExpanders, and region: 'west' placeHolders
            // have the re expand tool at the *top* with a bit of space.
            if (!me.hideCollapseTool) {
                toolAtTop = isLeft || (isRight && me.isPlaceHolderCollapse());
                result[toolAtTop ? 'items' : 'tools'] = [{
                    xtype: 'tool',
                    type: 'expand-' + me.getOppositeDirection(direction),
                    uiCls: ['top'],
                    handler: me.toggleCollapse,
                    scope: me
                }];
            }
            result = new Ext.panel.Header(result);
            result.addClsWithUI(me.getHeaderCollapsedClasses(result));
            return result;
        },

        // private
        // Create the class array to add to the Header when collpsed.
        getHeaderCollapsedClasses: function(header) {
            var me = this,
                collapsedCls = me.collapsedCls,
                collapsedClasses;

            collapsedClasses = [ collapsedCls, collapsedCls + '-' + header.dock];
            if (me.border && (!me.frame || (me.frame && Ext.supports.CSS3BorderRadius))) {
                collapsedClasses.push(collapsedCls + '-border-' + header.dock);
            }
            return collapsedClasses;
        },

        /**
         * @private
         * Called before the change from default, configured state into the collapsed state.
         * This method may be called at render time to enable rendering in an initially collapsed state,
         * or at runtime when an existing, fully layed out Panel may be collapsed.
         * It basically saves configs which need to be clobbered for the duration of the collapsed state.
         */
        beginCollapse: function() {
            var me = this,
                lastBox = me.lastBox,
                rendered = me.rendered,
                collapseMemento = me.collapseMemento || (me.collapseMemento = new Ext.util.Memento(me)),
                sizeModel = me.getSizeModel(),
                reExpander;

            // When we collapse a panel, the panel is in control of one dimension (depending on
            // collapse direction) and sets that on the component. We must restore the user's
            // original value (including non-existance) when we expand. Using this technique, we
            // mimic setCalculatedSize for the dimension we do not control and setSize for the
            // one we do (only while collapsed).
            // Additionally, the panel may have a shrink wrapped width and/or height. For shrinkWrapped
            // panels this can be problematic, since a collapsed, shrink-wrapped panel has no way
            // of determining its width (or height if the collapse direction is horizontal). It is
            // therefore necessary to capture both the width and height regardless of collapse direction.
            // This allows us to set a configured width or height on the panel when it is collapsed,
            // and it will be restored to an unconfigured-width shrinkWrapped state on expand.
            collapseMemento.capture(['height', 'minHeight', 'width', 'minWidth']);
            if (lastBox) {
                collapseMemento.capture(me.restoreDimension(), lastBox, 'last.');
            }
            // If the panel has a shrinkWrapped height/width and is already rendered, configure its width/height as its calculated width/height,
            // so that the collapsed header will have the same width or height as the panel did before it was collapsed.
            // If the shrinkWrapped panel has not yet been rendered, as will be the case when a panel is initially configured with
            // collapsed:true, we attempt to use the configured width/height, and fall back to minWidth or minHeight if
            // width/height has not been configured, and fall back to a value of 100 if a minWidth/minHeight has not been configured.
            if (me.collapsedVertical()) {
                if (sizeModel.width.shrinkWrap) {
                    me.width = rendered ? me.getWidth() : me.width || me.minWidth || 100;
                }
                delete me.height;
                me.minHeight = 0;
            } else if (me.collapsedHorizontal()) {
                if (sizeModel.height.shrinkWrap) {
                    me.height = rendered ? me.getHeight() : me.height || me.minHeight || 100;
                }
                delete me.width;
                me.minWidth = 0;
            }

            if (me.ownerCt) {
                me.ownerCt.getLayout().beginCollapse(me);
            }

            // Get a reExpander header. This will return the Panel Header if the Header is in the correct orientation
            // If we are using the Header as the reExpander, change its UI to collapsed state
            if (!me.isPlaceHolderCollapse()) {
                if (me.header === (reExpander = me.getReExpander())) {
                    me.header.addClsWithUI(me.getHeaderCollapsedClasses(me.header));

                    // Ensure that the reExpander has the correct framing applied.
                    if (me.header.rendered) {
                        me.header.updateFrame();
                    }
                }
                // We're going to use a temporary reExpander: show it.
                else {
                    if (reExpander.el) {
                        reExpander.el.show();
                        reExpander.hidden = false;
                    }
                }
            }
            if (me.resizer) {
                me.resizer.disable();
            }
        },

        beginExpand: function() {
            var me = this,
                lastBox = me.lastBox,
                collapseMemento = me.collapseMemento,
                restoreDimension = this.restoreDimension(),
                reExpander;

            collapseMemento.restore(['minHeight', 'minWidth', restoreDimension]);
            if (lastBox) {
                collapseMemento.restore(restoreDimension, true, lastBox, 'last.');
            }

            if (me.ownerCt) {
                me.ownerCt.getLayout().beginExpand(me);
            }

            if (!me.isPlaceHolderCollapse()) {
                // If we have been using our Header as the reExpander then restore the Header to expanded UI
                if (me.header === (reExpander = me.getReExpander())) {
                    me.header.removeClsWithUI(me.getHeaderCollapsedClasses(me.header));

                    // Ensure that the reExpander has the correct framing applied.
                    if (me.header.rendered) {
                        me.header.updateFrame();
                    }
                }
                // We've been using a temporary reExpander: hide it.
                else {
                    reExpander.hidden = true;
                    reExpander.el.hide();
                }
            }
            if (me.resizer) {
                me.resizer.enable();
            }
        },

        /**
         * Collapses the panel body so that the body becomes hidden. Docked Components parallel to the border towards which
         * the collapse takes place will remain visible. Fires the {@link #beforecollapse} event which will cancel the
         * collapse action if it returns false.
         *
         * @param {String} [direction] The direction to collapse towards. Must be one of
         *
         *   - Ext.Component.DIRECTION_TOP
         *   - Ext.Component.DIRECTION_RIGHT
         *   - Ext.Component.DIRECTION_BOTTOM
         *   - Ext.Component.DIRECTION_LEFT
         *
         * Defaults to {@link #collapseDirection}.
         *
         * @param {Boolean} [animate] True to animate the transition, else false (defaults to the value of the
         * {@link #animCollapse} panel config)
         * @return {Ext.panel.Panel} this
         */
        collapse: function(direction, animate) {
            var me = this,
                collapseDir = direction || me.collapseDirection,
                ownerCt = me.ownerCt;

            if (me.isCollapsingOrExpanding) {
                return me;
            }

            if (arguments.length < 2) {
                animate = me.animCollapse;
            }

            if (me.collapsed || me.fireEvent('beforecollapse', me, direction, animate) === false) {
                return me;
            }

            if (ownerCt && me.isPlaceHolderCollapse()) {
                return me.placeholderCollapse(direction, animate);
            }

            me.collapsed = collapseDir;
            me.beginCollapse();

            me.fireHierarchyEvent('collapse');

            return me.doCollapseExpand(1, animate);
        },

        doCollapseExpand: function (flags, animate) {
            var me = this,
                originalAnimCollapse = me.animCollapse,
                ownerLayout = me.ownerLayout;

            // we need to temporarily set animCollapse to the animate value here because ContextItem
            // uses the animCollapse property to determine if the collapse/expand should be animated
            me.animCollapse = animate;

            // Flag used by the layouy ContextItem to impose an animation policy based upon the
            // collapse direction and the animCollapse setting.
            me.isCollapsingOrExpanding = flags;

            if (ownerLayout && !animate) {
                ownerLayout.onContentChange(me);
            } else {
                me.updateLayout({ isRoot: true });
            }

            // set animCollapse back to its original value
            me.animCollapse = originalAnimCollapse;

            return me;
        },

        /**
         * Invoked after the Panel is Collapsed.
         *
         * @param {Boolean} animated
         *
         * @template
         * @protected
         */
        afterCollapse: function(animated) {
            var me = this,
                ownerLayout = me.ownerLayout;

            me.isCollapsingOrExpanding = 0;
            if (me.collapseTool) {
                me.collapseTool.setType('expand-' + me.getOppositeDirection(me.collapseDirection));
            }

            if (ownerLayout && animated) {
                ownerLayout.onContentChange(me);
            }

            me.setHiddenDocked();
            me.fireEvent('collapse', me);
        },

        setHiddenDocked: function(){
            // Hide Panel content except reExpander using visibility to prevent focusing of contained elements.
            // Track what we hide to re-show on expand
            var me = this,
                toHide = me.hiddenOnCollapse,
                reExpander = me.getReExpander(),
                items = me.getDockedItems(),
                len = items.length,
                i = 0,
                item;

            toHide.add(me.body);
            for (; i < len; i++) {
                item = items[i];
                if (item && item !== reExpander && item.el) {
                    toHide.add(item.el);
                }
            }
            toHide.setStyle('visibility', 'hidden');
        },

        restoreHiddenDocked: function(){
            var toShow = this.hiddenOnCollapse;
            // Re-show Panel content which was hidden after collapse.
            toShow.setStyle('visibility', '');
            toShow.clear();
        },

        getPlaceholder: function(direction) {
            var me = this,
                collapseDir = direction || me.collapseDirection,
                listeners = null,
                placeholder = me.placeholder;

            if (!placeholder) {
                if (me.floatable || (me.collapsible && me.titleCollapse)) {
                    listeners = {
                        click: {
                            fn: me.floatable ? me.floatCollapsedPanel : me.toggleCollapse,
                            element: 'el',
                            scope: me
                        }
                    };
                }

                me.placeholder = placeholder = Ext.widget(me.createReExpander(collapseDir, {
                    id: me.id + '-placeholder',
                    listeners: listeners
                }));
            }

            // User created placeholder was passed in
            if (!placeholder.placeholderFor) {
                // Handle the case of a placeholder config
                if (!placeholder.isComponent) {
                    me.placeholder = placeholder = me.lookupComponent(placeholder);
                }
                Ext.applyIf(placeholder, {
                    margins: me.margins,
                    placeholderFor: me
                });

                placeholder.addCls([Ext.baseCSSPrefix + 'region-collapsed-placeholder', Ext.baseCSSPrefix + 'region-collapsed-' + collapseDir + '-placeholder', me.collapsedCls]);
            }

            return placeholder;
        },

        placeholderCollapse: function(direction, animate) {
            var me = this,
                ownerCt = me.ownerCt,
                collapseDir = direction || me.collapseDirection,
                floatCls = Ext.baseCSSPrefix + 'border-region-slide-in',
                placeholder = me.getPlaceholder(direction);

            me.isCollapsingOrExpanding = 1;

            // Upcoming layout run will ignore this Component
            me.hidden = true;
            me.collapsed = collapseDir;

            if (placeholder.rendered) {
                // We may have been added to another Container from that in which we rendered the placeholder
                if (placeholder.el.dom.parentNode !== me.el.dom.parentNode) {
                    me.el.dom.parentNode.insertBefore(placeholder.el.dom, me.el.dom);
                }

                placeholder.hidden = false;
                placeholder.el.show();
                ownerCt.updateLayout();
            } else {
                ownerCt.insert(ownerCt.items.indexOf(me), placeholder);
            }

            if (me.rendered) {
                // We MUST NOT hide using display because that resets all scroll information.
                me.el.setVisibilityMode(me.placeholderCollapseHideMode);
                if (animate) {
                    me.el.addCls(floatCls);
                    placeholder.el.hide();

                    me.el.slideOut(collapseDir.substr(0, 1), {
                        preserveScroll: true,
                        duration: Ext.Number.from(animate, Ext.fx.Anim.prototype.duration),
                        listeners: {
                            afteranimate: function() {
                                me.el.removeCls(floatCls);
                                /* We need to show the element so that slideIn will work correctly. However, if we leave it
                                   visible then it can be seen before the animation starts, causing a flicker. The solution,
                                   borrowed from date picker, is to hide it using display none. The slideIn effect includes
                                   a call to fixDisplay() that will undo the display none at the appropriate time.
                                 */
                                placeholder.el.show().setStyle('display', 'none').slideIn(collapseDir.substr(0, 1), {
                                    easing: 'linear',
                                    duration: 100,
                                    listeners: {
                                        afteranimate: function() {
                                            placeholder.focus();
                                            me.isCollapsingOrExpanding = 0;
                                            me.fireEvent('collapse', me);
                                        }
                                    }
                                });
                            }
                        }
                    });
                } else {
                    me.el.hide();
                    me.isCollapsingOrExpanding = 0;
                    me.fireEvent('collapse', me);
                }
            } else {
                me.isCollapsingOrExpanding = 0;
                me.fireEvent('collapse', me);
            }

            return me;
        },

        floatCollapsedPanel: function() {
            var me = this,
                placeholder = me.placeholder,
                pb = placeholder.getBox(true),
                myBox,
                floatCls = Ext.baseCSSPrefix + 'border-region-slide-in',
                collapsed = me.collapsed,
                layoutOwner = me.ownerCt || me,
                slideDirection;

            // Already floated
            if (me.el.hasCls(floatCls)) {
                me.slideOutFloatedPanel();
                return;
            }

            if (me.isSliding) {
                return;
            }
            me.isSliding = true;

            // Function to be called when the mouse leaves the floated Panel
            // Slide out when the mouse leaves the region bounded by the slid Component and its placeholder.
            function onMouseLeaveFloated(e) {
                if (!me.isDestroyed) {
                    var slideRegion = me.el.getRegion().union(placeholder.el.getRegion()).adjust(1, -1, -1, 1);

                    // If mouse is not within slide Region, slide it out
                    if (!slideRegion.contains(e.getPoint())) {
                        me.slideOutFloatedPanel();
                    }
                }
            }

            // Lay out in fully expanded mode to ensure we are at the correct size, and collect our expanded box
            me.placeholder.el.hide();
            me.placeholder.hidden = true;
            me.el.show();
            me.hidden = false;
            me.collapsed = false;
            layoutOwner.updateLayout();
            myBox = me.getBox(true);

            // Then go back immediately to collapsed state from which to initiate the float into view.
            me.placeholder.el.show();
            me.placeholder.hidden = false;
            me.el.hide();
            me.hidden = true;
            me.collapsed = collapsed;
            layoutOwner.updateLayout();

            // Monitor for mouseouting of the placeholder. Hide it if they exit for half a second or more
            me.placeholderMouseMon = placeholder.el.monitorMouseLeave(500, onMouseLeaveFloated);
            me.panelMouseMon       = me.el.monitorMouseLeave(500, onMouseLeaveFloated);
            me.el.addCls(floatCls);

            // Hide collapse tool in header if there is one (we might be headerless)
            if (me.collapseTool) {
                me.collapseTool.el.hide();
            }

            switch (me.collapsed) {
                case 'top':
                    me.el.setLeftTop(pb.x, pb.y + pb.height - 1);
                    slideDirection = 't';
                    break;
                case 'right':
                    me.el.setLeftTop(pb.x - myBox.width + 1, pb.y);
                    slideDirection = 'r';
                    break;
                case 'bottom':
                    me.el.setLeftTop(pb.x, pb.y - myBox.height + 1);
                    slideDirection = 'b';
                    break;
                case 'left':
                    me.el.setLeftTop(pb.x + pb.width - 1, pb.y);
                    slideDirection = 'l';
                    break;
            }

            // Remember how we are really collapsed so we can restore it, but also so we can
            // become a layoutRoot while we are floated:
            me.floatedFromCollapse = me.collapsed;
            me.collapsed = me.hidden = false;

            me.el.slideIn(slideDirection, {
                preserveScroll: true,
                listeners: {
                    afteranimate: function() {
                        me.isSliding = false;
                    }
                }
            });
        },

        isLayoutRoot: function() {
            if (this.floatedFromCollapse) {
                return true;
            }
            return this.callParent();
        },

        slideOutFloatedPanel: function() {
            var me = this,
                compEl = this.el,
                collapseDirection;

            if (me.isSliding) {
                return;
            }

            me.isSliding = true;

            me.slideOutFloatedPanelBegin();

            if (typeof me.collapsed == 'string') {
                collapseDirection = me.collapsed.charAt(0);
            }

            compEl.slideOut(collapseDirection, {
                preserveScroll: true,
                listeners: {
                    afteranimate: function() {
                        me.slideOutFloatedPanelEnd();
                        // this would be in slideOutFloatedPanelEnd except that the only other
                        // caller removes this cls later
                        me.el.removeCls(Ext.baseCSSPrefix + 'border-region-slide-in');
                        me.isSliding = false;
                    }
                }
            });
        },

        /**
         * This method begins the slide out of the floated panel.
         * @private
         */
        slideOutFloatedPanelBegin: function() {
            var me = this,
                compEl = this.el;

            me.collapsed = me.floatedFromCollapse;
            me.hidden = true;
            me.floatedFromCollapse = null;

            // Remove mouse leave monitors
            compEl.un(me.panelMouseMon);
            me.placeholder.el.un(me.placeholderMouseMon);
        },

        /**
         * This method cleans up after the slide out of the floated panel.
         * @private
         */
        slideOutFloatedPanelEnd: function() {
            if (this.collapseTool) {
                this.collapseTool.el.show();
            }
        },

        /**
         * Expands the panel body so that it becomes visible.  Fires the {@link #beforeexpand} event which will
         * cancel the expand action if it returns false.
         * @param {Boolean} [animate] True to animate the transition, else false (defaults to the value of the
         * {@link #animCollapse} panel config)
         * @return {Ext.panel.Panel} this
         */
        expand: function(animate) {
            var me = this;

            if (me.isCollapsingOrExpanding) {
                return me;
            }

            if (!arguments.length) {
                animate = me.animCollapse;
            }

            if (!me.collapsed && !me.floatedFromCollapse) {
                return me;
            }

            if (me.fireEvent('beforeexpand', me, animate) === false) {
                return me;
            }

            if (me.isPlaceHolderCollapse()) {
                return me.placeholderExpand(animate);
            }

            me.restoreHiddenDocked();
            me.beginExpand();
            me.collapsed = false;

            me.fireHierarchyEvent('expand');

            return me.doCollapseExpand(2, animate);
        },

        placeholderExpand: function(animate) {
            var me = this,
                collapseDir = me.collapsed,
                floatCls = Ext.baseCSSPrefix + 'border-region-slide-in',
                finalPos,
                floatedPos,
                slideInDirection;

            if (me.floatedFromCollapse) {
                floatedPos = me.getPosition(true);
                // these are the same cleanups performed by the normal slideOut mechanism:
                me.slideOutFloatedPanelBegin();
                me.slideOutFloatedPanelEnd();
            }

            me.isCollapsingOrExpanding = 2;

            // Expand me and hide the placeholder
            me.placeholder.hidden = true;
            me.placeholder.el.hide();
            me.collapsed = false;
            me.show();

            if (animate) {
                // Floated, move it back to the floated pos, and thence into the correct place
                if (floatedPos) {
                    finalPos = me.el.getXY();
                    me.el.setLeftTop(floatedPos[0], floatedPos[1]);
                    me.el.moveTo(finalPos[0], finalPos[1], {
                        duration: Ext.Number.from(animate, Ext.fx.Anim.prototype.duration),
                        listeners: {
                            afteranimate: function() {
                                me.el.removeCls(floatCls);
                                me.isCollapsingOrExpanding = 0;
                                me.fireEvent('expand', me);
                            }
                        }
                    });
                }
                // Not floated, slide it in to the correct place
                else {
                    me.hidden = true;
                    me.el.addCls(floatCls);
                    me.el.hide();
                    me.collapsed = collapseDir;
                    me.placeholder.show();
                    slideInDirection = collapseDir.substr(0, 1);

                    // Slide this Component's el back into place, after which we lay out AGAIN
                    me.hidden = false;
                    me.el.slideIn(slideInDirection, {
                        preserveScroll: true,
                        duration: Ext.Number.from(animate, Ext.fx.Anim.prototype.duration),
                        listeners: {
                            afteranimate: function() {
                                me.collapsed = false;

                                // the ordering of these two lines appears to be important in
                                // IE9.  There is an odd expand issue in IE 9 in the border layout
                                // example that causes the index1 child of the south dock region
                                // to get 'hidden' after a collapse / expand cycle.  See
                                // EXTJSIV-5318 for details
                                me.el.removeCls(floatCls);
                                me.placeholder.hide();

                                me.isCollapsingOrExpanding = 0;
                                me.fireEvent('expand', me);
                            }
                        }
                    });
                }

            } else {
                me.isCollapsingOrExpanding = 0;
                me.fireEvent('expand', me);
            }

            return me;
        },

        /**
         * Invoked after the Panel is Expanded.
         *
         * @param {Boolean} animated
         *
         * @template
         * @protected
         */
        afterExpand: function(animated) {
            var me = this,
                ownerLayout = me.ownerLayout;

            me.isCollapsingOrExpanding = 0;
            if (me.collapseTool) {
                me.collapseTool.setType('collapse-' + me.collapseDirection);
            }

            if (ownerLayout && animated) {
                ownerLayout.onContentChange(me);
            }

            me.fireEvent('expand', me);
        },

        // inherit docs
        setBorder: function(border, targetEl) {
            if (targetEl) {
                // skip out here, the panel will set the border on the body/header during rendering
                return;
            }

            var me = this,
                header = me.header;

            if (!border) {
                border = 0;
            } else {
                border = Ext.Element.unitizeBox((border === true) ? 1 : border);
            }

            if (header) {
                if (header.isHeader) {
                    header.setBorder(border);
                } else {
                    header.border = border;
                }
            }

            if (me.rendered && me.bodyBorder !== false) {
                me.body.setStyle('border-width', border);
            }
            me.updateLayout();

            me.border = border;
        },

        /**
         * Shortcut for performing an {@link #method-expand} or {@link #method-collapse} based on the current state of the panel.
         * @return {Ext.panel.Panel} this
         */
        toggleCollapse: function() {
            return (this.collapsed || this.floatedFromCollapse) ? this.expand() : this.collapse();
        },

        // private
        getKeyMap : function() {
            return this.keyMap || (this.keyMap = new Ext.util.KeyMap(Ext.apply({
                target: this.el
            }, this.keys)));
        },

        // private
        initDraggable : function(){
            /**
             * @property {Ext.dd.DragSource} dd
             * If this Panel is configured {@link #cfg-draggable}, this property will contain an instance of {@link
             * Ext.dd.DragSource} which handles dragging the Panel.
             *
             * The developer must provide implementations of the abstract methods of {@link Ext.dd.DragSource} in order to
             * supply behaviour for each stage of the drag/drop process. See {@link #cfg-draggable}.
             */
            this.dd = new Ext.panel.DD(this, Ext.isBoolean(this.draggable) ? null : this.draggable);
        },

        // private - helper function for ghost
        ghostTools : function() {
            var tools = [],
                header = this.header,
                headerTools = header ? header.query('tool[hidden=false]') : [],
                t, tLen, tool;

            if (headerTools.length) {
                t = 0;
                tLen = headerTools.length;

                for (; t < tLen; t++) {
                    tool = headerTools[t];

                    // Some tools can be full components, and copying them into the ghost
                    // actually removes them from the owning panel. You could also potentially
                    // end up with duplicate DOM ids as well. To avoid any issues we just make
                    // a simple bare-minimum clone of each tool for ghosting purposes.
                    tools.push({
                        type: tool.type
                    });
                }
            } else {
                tools = [{
                    type: 'placeholder'
                }];
            }
            return tools;
        },

        // private - used for dragging
        ghost: function(cls) {
            var me = this,
                ghostPanel = me.ghostPanel,
                box = me.getBox(),
                header;

            if (!ghostPanel) {
                ghostPanel = new Ext.panel.Panel({
                    renderTo: document.body,
                    floating: {
                        shadow: false
                    },
                    frame: me.frame && !me.alwaysFramed,
                    alwaysFramed: me.alwaysFramed,
                    overlapHeader: me.overlapHeader,
                    headerPosition: me.headerPosition,
                    baseCls: me.baseCls,
                    cls: me.baseCls + '-ghost ' + (cls ||'')
                });
                me.ghostPanel = ghostPanel;
            } else {
                ghostPanel.el.show();
            }
            ghostPanel.floatParent = me.floatParent;
            if (me.floating) {
                ghostPanel.setZIndex(Ext.Number.from(me.el.getStyle('zIndex'), 0));
            } else {
                ghostPanel.toFront();
            }
            if (!(me.preventHeader || (me.header === false))) {
                header = ghostPanel.header;
                // restore options
                if (header) {
                    header.suspendLayouts();
                    Ext.Array.forEach(header.query('tool'), header.remove, header);
                    header.resumeLayouts();
                }
                ghostPanel.addTool(me.ghostTools());
                ghostPanel.setTitle(me.title);
                ghostPanel.setIconCls(me.iconCls);
            }

            ghostPanel.setPagePosition(box.x, box.y);
            ghostPanel.setSize(box.width, box.height);
            me.el.hide();
            return ghostPanel;
        },

        // private
        unghost: function(show, matchPosition) {
            var me = this;
            if (!me.ghostPanel) {
                return;
            }
            if (show !== false) {
                // Show el first, so that position adjustment in setPagePosition
                // will work when relative positioned elements have their XY read.
                me.el.show();
                if (matchPosition !== false) {
                    me.setPagePosition(me.ghostPanel.el.getXY());
                    if (me.hideMode == 'offsets') {
                        // clear the hidden style because we just repositioned
                        delete me.el.hideModeStyles;
                    }
                }
                Ext.defer(me.focus, 10, me);
            }
            me.ghostPanel.el.hide();
        },

        beginDrag: function() {
            if (this.floatingDescendants) {
                this.floatingDescendants.hide();
            }
        },

        endDrag: function() {
            if (this.floatingDescendants) {
                this.floatingDescendants.show();
            }
        },

        initResizable: function(resizable) {
            if (this.collapsed) {
                resizable.disabled = true;
            }
            this.callParent([resizable]);
        }
    }, function() {
        this.prototype.animCollapse = Ext.enableFx;
    });