    /**
     * This class specifies the definition for a column inside a {@link Ext.grid.Panel}. It encompasses
     * both the grid header configuration as well as displaying data within the grid itself. If the
     * {@link #columns} configuration is specified, this column will become a column group and can
     * contain other columns inside. In general, this class will not be created directly, rather
     * an array of column configurations will be passed to the grid:
     *
     *     @example
     *     Ext.create('Ext.data.Store', {
     *         storeId:'employeeStore',
     *         fields:['firstname', 'lastname', 'seniority', 'dep', 'hired'],
     *         data:[
     *             {firstname:"Michael", lastname:"Scott", seniority:7, dep:"Management", hired:"01/10/2004"},
     *             {firstname:"Dwight", lastname:"Schrute", seniority:2, dep:"Sales", hired:"04/01/2004"},
     *             {firstname:"Jim", lastname:"Halpert", seniority:3, dep:"Sales", hired:"02/22/2006"},
     *             {firstname:"Kevin", lastname:"Malone", seniority:4, dep:"Accounting", hired:"06/10/2007"},
     *             {firstname:"Angela", lastname:"Martin", seniority:5, dep:"Accounting", hired:"10/21/2008"}
     *         ]
     *     });
     *
     *     Ext.create('Ext.grid.Panel', {
     *         title: 'Column Demo',
     *         store: Ext.data.StoreManager.lookup('employeeStore'),
     *         columns: [
     *             {text: 'First Name',  dataIndex:'firstname'},
     *             {text: 'Last Name',  dataIndex:'lastname'},
     *             {text: 'Hired Month',  dataIndex:'hired', xtype:'datecolumn', format:'M'},
     *             {text: 'Department (Yrs)', xtype:'templatecolumn', tpl:'{dep} ({seniority})'}
     *         ],
     *         width: 400,
     *         forceFit: true,
     *         renderTo: Ext.getBody()
     *     });
     *
     * # Convenience Subclasses
     *
     * There are several column subclasses that provide default rendering for various data types
     *
     *  - {@link Ext.grid.column.Action}: Renders icons that can respond to click events inline
     *  - {@link Ext.grid.column.Boolean}: Renders for boolean values
     *  - {@link Ext.grid.column.Date}: Renders for date values
     *  - {@link Ext.grid.column.Number}: Renders for numeric values
     *  - {@link Ext.grid.column.Template}: Renders a value using an {@link Ext.XTemplate} using the record data
     *
     * # Setting Sizes
     *
     * The columns are laid out by a {@link Ext.layout.container.HBox} layout, so a column can either
     * be given an explicit width value or a flex configuration. If no width is specified the grid will
     * automatically the size the column to 100px. For column groups, the size is calculated by measuring
     * the width of the child columns, so a width option should not be specified in that case.
     *
     * # Header Options
     *
     *  - {@link #text}: Sets the header text for the column
     *  - {@link #sortable}: Specifies whether the column can be sorted by clicking the header or using the column menu
     *  - {@link #hideable}: Specifies whether the column can be hidden using the column menu
     *  - {@link #menuDisabled}: Disables the column header menu
     *  - {@link #cfg-draggable}: Specifies whether the column header can be reordered by dragging
     *  - {@link #groupable}: Specifies whether the grid can be grouped by the column dataIndex. See also {@link Ext.grid.feature.Grouping}
     *
     * # Data Options
     *
     *  - {@link #dataIndex}: The dataIndex is the field in the underlying {@link Ext.data.Store} to use as the value for the column.
     *  - {@link #renderer}: Allows the underlying store value to be transformed before being displayed in the grid
     */
    Ext.define('Ext.grid.column.Column', {
        extend: 'Ext.grid.header.Container',
        alias: 'widget.gridcolumn',
        requires: ['Ext.util.KeyNav', 'Ext.grid.ColumnComponentLayout', 'Ext.grid.ColumnLayout'],
        alternateClassName: 'Ext.grid.Column',

        baseCls: Ext.baseCSSPrefix + 'column-header ' + Ext.baseCSSPrefix + 'unselectable',

        // Not the standard, automatically applied overCls because we must filter out overs of child headers.
        hoverCls: Ext.baseCSSPrefix + 'column-header-over',

        handleWidth: 5,

        sortState: null,

        possibleSortStates: ['ASC', 'DESC'],

        childEls: [
            'titleEl', 'triggerEl', 'textEl'
        ],

        renderTpl:
            '<div id="{id}-titleEl" {tipMarkup}class="' + Ext.baseCSSPrefix + 'column-header-inner">' +
                '<span id="{id}-textEl" class="' + Ext.baseCSSPrefix + 'column-header-text">' +
                    '{text}' +
                '</span>' +
                '<tpl if="!menuDisabled">'+
                    '<div id="{id}-triggerEl" class="' + Ext.baseCSSPrefix + 'column-header-trigger"></div>'+
                '</tpl>' +
            '</div>' +
            '{%this.renderContainer(out,values)%}',

        /**
         * @cfg {Object[]} columns
         * An optional array of sub-column definitions. This column becomes a group, and houses the columns defined in the
         * `columns` config.
         *
         * Group columns may not be sortable. But they may be hideable and moveable. And you may move headers into and out
         * of a group. Note that if all sub columns are dragged out of a group, the group is destroyed.
         */

        /**
         * @override
         * @cfg {String} stateId
         * An identifier which identifies this column uniquely within the owning grid's {@link #stateful state}.
         *
         * This does not have to be *globally* unique. A column's state is not saved standalone. It is encapsulated within
         * the owning grid's state.
         */

        /**
         * @cfg {String} dataIndex
         * The name of the field in the grid's {@link Ext.data.Store}'s {@link Ext.data.Model} definition from
         * which to draw the column's value. **Required.**
         */
        dataIndex: null,

        /**
         * @cfg {String} text
         * The header text to be used as innerHTML (html tags are accepted) to display in the Grid.
         * **Note**: to have a clickable header with no text displayed you can use the default of `&#160;` aka `&nbsp;`.
         */
        text: '&#160;',

        /**
         * @cfg {String} header
         * The header text.
         * @deprecated 4.0 Use {@link #text} instead.
         */

        /**
         * @cfg {String} menuText
         * The text to render in the column visibility selection menu for this column.  If not
         * specified, will default to the text value.
         */
        menuText: null,

        /**
         * @cfg {String} [emptyCellText=undefined]
         * The text to diplay in empty cells (cells with a value of `undefined`, `null`, or `''`).
         *
         * Defaults to `&#160;` aka `&nbsp;`.
         */
        emptyCellText: '&#160;',

        /**
         * @cfg {Boolean} sortable
         * False to disable sorting of this column. Whether local/remote sorting is used is specified in
         * `{@link Ext.data.Store#remoteSort}`.
         */
        sortable: true,

        /**
         * @cfg {Boolean} groupable
         * If the grid uses a {@link Ext.grid.feature.Grouping}, this option may be used to disable the header menu
         * item to group by the column selected. By default, the header menu group option is enabled. Set to false to
         * disable (but still show) the group option in the header menu for the column.
         */

        /**
         * @cfg {Boolean} fixed
         * True to prevent the column from being resizable.
         * @deprecated 4.0 Use {@link #resizable} instead.
         */

        /**
         * @cfg {Boolean} [locked=false]
         * True to lock this column in place.  Implicitly enables locking on the grid.
         * See also {@link Ext.grid.Panel#enableLocking}.
         */

        /**
         * @cfg {Boolean} resizable
         * False to prevent the column from being resizable.
         */
        resizable: true,

        /**
         * @cfg {Boolean} hideable
         * False to prevent the user from hiding this column.
         */
        hideable: true,

        /**
         * @cfg {Boolean} menuDisabled
         * True to disable the column header menu containing sort/hide options.
         */
        menuDisabled: false,

        /**
         * @cfg {Function/String} renderer
         * A renderer is an 'interceptor' method which can be used to transform data (value, appearance, etc.)
         * before it is rendered. Example:
         *
         *     {
         *         renderer: function(value){
         *             if (value === 1) {
         *                 return '1 person';
         *             }
         *             return value + ' people';
         *         }
         *     }
         *
         * Additionally a string naming an {@link Ext.util.Format} method can be passed:
         *
         *     {
         *         renderer: 'uppercase'
         *     }
         *
         * @cfg {Object} renderer.value The data value for the current cell
         * @cfg {Object} renderer.metaData A collection of metadata about the current cell; can be used or modified
         * by the renderer. Recognized properties are: tdCls, tdAttr, and style.
         * @cfg {Ext.data.Model} renderer.record The record for the current row
         * @cfg {Number} renderer.rowIndex The index of the current row
         * @cfg {Number} renderer.colIndex The index of the current column
         * @cfg {Ext.data.Store} renderer.store The data store
         * @cfg {Ext.view.View} renderer.view The current view
         * @cfg {String} renderer.return The HTML string to be rendered.
         */
        renderer: false,

        /**
         * @cfg {Object} scope
         * The scope to use when calling the {@link #renderer} function.
         */

        /**
         * @method defaultRenderer
         * When defined this will take precedence over the {@link Ext.grid.column.Column#renderer renderer} config.
         * This is meant to be defined in subclasses that wish to supply their own renderer.
         * @protected
         * @template
         */

        /**
         * @cfg {Function} editRenderer
         * A renderer to be used in conjunction with {@link Ext.grid.plugin.RowEditing RowEditing}. This renderer is used to
         * display a custom value for non-editable fields.
         */
        editRenderer: false,

        /**
         * @cfg {String} align
         * Sets the alignment of the header and rendered columns.
         * Possible values are: `'left'`, `'center'`, and `'right'`.
         */
        align: 'left',

        /**
         * @cfg {Boolean} draggable
         * False to disable drag-drop reordering of this column.
         */
        draggable: true,

        /**
         * @cfg {String} tooltip
         * A tooltip to display for this column header
         */

        /**
         * @cfg {String} [tooltipType="qtip"]
         * The type of {@link #tooltip} to use. Either 'qtip' for QuickTips or 'title' for title attribute.
         */
        tooltipType: 'qtip',

        // Header does not use the typical ComponentDraggable class and therefore we
        // override this with an emptyFn. It is controlled at the HeaderDragZone.
        initDraggable: Ext.emptyFn,

        /**
         * @cfg {String} tdCls
         * A CSS class names to apply to the table cells for this column.
         */

        /**
         * @cfg {Object/String} editor
         * An optional xtype or config object for a {@link Ext.form.field.Field Field} to use for editing.
         * Only applicable if the grid is using an {@link Ext.grid.plugin.Editing Editing} plugin.
         */

        /**
         * @cfg {Object/String} field
         * Alias for {@link #editor}.
         * @deprecated 4.0.5 Use {@link #editor} instead.
         */

        /**
         * @property {Ext.Element} triggerEl
         * Element that acts as button for column header dropdown menu.
         */

        /**
         * @property {Ext.Element} textEl
         * Element that contains the text in column header.
         */

        /**
         * @property {Boolean} isHeader
         * Set in this class to identify, at runtime, instances which are not instances of the
         * HeaderContainer base class, but are in fact, the subclass: Header.
         */
        isHeader: true,

        componentLayout: 'columncomponent',

        // We need to override the default component resizable behaviour here
        initResizable: Ext.emptyFn,

        initComponent: function() {
            var me = this,
                renderer;

            if (Ext.isDefined(me.header)) {
                me.text = me.header;
                delete me.header;
            }

            if (!me.triStateSort) {
                me.possibleSortStates.length = 2;
            }

            // A group header; It contains items which are themselves Headers
            if (Ext.isDefined(me.columns)) {
                me.isGroupHeader = true;

                //<debug>
                if (me.dataIndex) {
                    Ext.Error.raise('Ext.grid.column.Column: Group header may not accept a dataIndex');
                }
                if ((me.width && me.width !== Ext.grid.header.Container.prototype.defaultWidth) || me.flex) {
                    Ext.Error.raise('Ext.grid.column.Column: Group header does not support setting explicit widths or flexs. The group header width is calculated by the sum of its children.');
                }
                //</debug>

                // The headers become child items
                me.items = me.columns;
                delete me.columns;
                delete me.flex;
                delete me.width;
                me.cls = (me.cls||'') + ' ' + Ext.baseCSSPrefix + 'group-header';
                me.sortable = false;
                me.resizable = false;
                me.align = 'center';
            } else {
                // If we are not a group header, then this is not to be used as a container, and must not have a container layout executed, and it must
                // acquire layout height from DOM content, not from child items.
                me.isContainer = false;

                // Flexed Headers need to have a minWidth defined so that they can never be squeezed out of existence by the
                // HeaderContainer's specialized Box layout, the ColumnLayout. The ColumnLayout's overridden calculateChildboxes
                // method extends the available layout space to accommodate the "desiredWidth" of all the columns.
                if (me.flex) {
                    me.minWidth = me.minWidth || Ext.grid.plugin.HeaderResizer.prototype.minColWidth;
                }
            }
            me.addCls(Ext.baseCSSPrefix + 'column-header-align-' + me.align);

            renderer = me.renderer;
            if (renderer) {
                // When specifying a renderer as a string, it always resolves
                // to Ext.util.Format
                if (typeof renderer == 'string') {
                    me.renderer = Ext.util.Format[renderer];
                }
                me.hasCustomRenderer = true;
            } else if (me.defaultRenderer) {
                me.scope = me;
                me.renderer = me.defaultRenderer;
            }

            // Initialize as a HeaderContainer
            me.callParent(arguments);

            me.on({
                element:  'el',
                click:    me.onElClick,
                dblclick: me.onElDblClick,
                scope:    me
            });
            me.on({
                element:    'titleEl',
                mouseenter: me.onTitleMouseOver,
                mouseleave: me.onTitleMouseOut,
                scope:      me
            });
        },

        onAdd: function(childHeader) {
            childHeader.isSubHeader = true;
            childHeader.addCls(Ext.baseCSSPrefix + 'group-sub-header');
            this.callParent(arguments);
        },

        onRemove: function(childHeader) {
            childHeader.isSubHeader = false;
            childHeader.removeCls(Ext.baseCSSPrefix + 'group-sub-header');
            this.callParent(arguments);
        },

        initRenderData: function() {
            var me = this,
                tipMarkup = '',
                tip = me.tooltip,
                attr = me.tooltipType == 'qtip' ? 'data-qtip' : 'title';

            if (!Ext.isEmpty(tip)) {
                tipMarkup = attr + '="' + tip + '" ';
            }

            return Ext.applyIf(me.callParent(arguments), {
                text: me.text,
                menuDisabled: me.menuDisabled,
                tipMarkup: tipMarkup
            });
        },

        applyColumnState: function (state) {
            var me = this,
                defined = Ext.isDefined;

            // apply any columns
            me.applyColumnsState(state.columns);

            // Only state properties which were saved should be restored.
            // (Only user-changed properties were saved by getState)
            if (defined(state.hidden)) {
                me.hidden = state.hidden;
            }
            if (defined(state.locked)) {
                me.locked = state.locked;
            }
            if (defined(state.sortable)) {
                me.sortable = state.sortable;
            }
            if (defined(state.width)) {
                delete me.flex;
                me.width = state.width;
            } else if (defined(state.flex)) {
                delete me.width;
                me.flex = state.flex;
            }
        },

        getColumnState: function () {
            var me = this,
                items = me.items.items,
                // Check for the existence of items, since column.Action won't have them
                iLen = items ? items.length : 0,
                i,
                columns = [],
                state = {
                    id: me.getStateId()
                };

            me.savePropsToState(['hidden', 'sortable', 'locked', 'flex', 'width'], state);

            if (me.isGroupHeader) {
                for (i = 0; i < iLen; i++) {
                    columns.push(items[i].getColumnState());
                }

                if (columns.length) {
                    state.columns = columns;
                }
            } else if (me.isSubHeader && me.ownerCt.hidden) {
                // don't set hidden on the children so they can auto height
                delete me.hidden;
            }

            if ('width' in state) {
                delete state.flex; // width wins
            }
            return state;
        },

        getStateId: function () {
            return this.stateId || this.headerId;
        },

        /**
         * Sets the header text for this Column.
         * @param {String} text The header to display on this Column.
         */
        setText: function(text) {
            this.text = text;
            if (this.rendered) {
                this.textEl.update(text);
            }
        },

        // Find the topmost HeaderContainer: An ancestor which is NOT a Header.
        // Group Headers are themselves HeaderContainers
        getOwnerHeaderCt: function() {
            return this.up(':not([isHeader])');
        },

        /**
         * Returns the index of this column only if this column is a base level Column. If it
         * is a group column, it returns `false`.
         * @return {Number}
         */
        getIndex: function() {
            return this.isGroupColumn ? false : this.getOwnerHeaderCt().getHeaderIndex(this);
        },

        /**
         * Returns the index of this column in the list of *visible* columns only if this column is a base level Column. If it
         * is a group column, it returns `false`.
         * @return {Number}
         */
        getVisibleIndex: function() {
            return this.isGroupColumn ? false : Ext.Array.indexOf(this.getOwnerHeaderCt().getVisibleGridColumns(), this);
        },

        beforeRender: function() {
            var me = this,
                grid = me.up('tablepanel');

            me.callParent();

            // Disable the menu if there's nothing to show in the menu, ie:
            // Column cannot be sorted, grouped or locked, and there are no grid columns which may be hidden
            if (grid && (!me.sortable || grid.sortableColumns === false) && !me.groupable &&
                         !me.lockable && (grid.enableColumnHide === false ||
                         !me.getOwnerHeaderCt().getHideableColumns().length)) {
                me.menuDisabled = true;
            }
        },

        afterRender: function() {
            var me = this,
                el = me.el;

            me.callParent(arguments);

            if (me.overCls) {
                el.addClsOnOver(me.overCls);
            }

            // BrowserBug: Ie8 Strict Mode, this will break the focus for this browser,
            // must be fixed when focus management will be implemented.
            if (!Ext.isIE8 || !Ext.isStrict) {
                me.mon(me.getFocusEl(), {
                    focus: me.onTitleMouseOver,
                    blur: me.onTitleMouseOut,
                    scope: me
                });
            }

            me.keyNav = new Ext.util.KeyNav(el, {
                enter: me.onEnterKey,
                down: me.onDownKey,
                scope: me
            });
        },

        // private
        // Inform the header container about the resize
        afterComponentLayout: function(width, height, oldWidth, oldHeight) {
            var me = this,
                ownerHeaderCt = me.getOwnerHeaderCt();

            me.callParent(arguments);

            if (ownerHeaderCt && (oldWidth != null || me.flex) && width !== oldWidth) {
                ownerHeaderCt.onHeaderResize(me, width, true);
            }
        },

        // private
        // After the container has laid out and stretched, it calls this to correctly pad the inner to center the text vertically
        // Total available header height must be passed to enable padding for inner elements to be calculated.
        setPadding: function(headerHeight) {
            var me = this,
                lineHeight = parseInt(me.textEl.getStyle('line-height'), 10),
                textHeight = me.textEl.dom.offsetHeight,
                titleEl = me.titleEl,
                availableHeight = headerHeight - me.el.getBorderWidth('tb'),
                titleElHeight;

            // Top title containing element must stretch to match height of sibling group headers
            if (!me.isGroupHeader) {
                if (titleEl.getHeight() < availableHeight) {
                    titleEl.setHeight(availableHeight);
                    // the column el's parent element (the 'innerCt') may have an incorrect height
                    // at this point because it may have been shrink wrapped prior to the titleEl's
                    // height being set, so we need to sync it up here
                    me.ownerCt.layout.innerCt.setHeight(headerHeight);
                }
            }
            titleElHeight = titleEl.getViewSize().height;

            // Vertically center the header text in potentially vertically stretched header
            if (textHeight) {
                if(lineHeight) {
                    textHeight = Math.ceil(textHeight / lineHeight) * lineHeight;
                }
                titleEl.setStyle({
                    paddingTop: Math.floor(Math.max(((titleElHeight - textHeight) / 2), 0)) + 'px'
                });
            }

            // Only IE needs this
            if (Ext.isIE && me.triggerEl) {
                me.triggerEl.setHeight(titleElHeight);
            }
        },

        onDestroy: function() {
            var me = this;
            // force destroy on the textEl, IE reports a leak
            Ext.destroy(me.textEl, me.keyNav, me.field);
            delete me.keyNav;
            me.callParent(arguments);
        },

        onTitleMouseOver: function() {
            this.titleEl.addCls(this.hoverCls);
        },

        onTitleMouseOut: function() {
            this.titleEl.removeCls(this.hoverCls);
        },

        onDownKey: function(e) {
            if (this.triggerEl) {
                this.onElClick(e, this.triggerEl.dom || this.el.dom);
            }
        },

        onEnterKey: function(e) {
            this.onElClick(e, this.el.dom);
        },

        /**
         * @private
         * Double click
         * @param e
         * @param t
         */
        onElDblClick: function(e, t) {
            var me = this,
                ownerCt = me.ownerCt;
            if (ownerCt && Ext.Array.indexOf(ownerCt.items, me) !== 0 && me.isOnLeftEdge(e) ) {
                ownerCt.expandToFit(me.previousSibling('gridcolumn'));
            }
        },

        onElClick: function(e, t) {

            // The grid's docked HeaderContainer.
            var me = this,
                ownerHeaderCt = me.getOwnerHeaderCt();

            if (ownerHeaderCt && !ownerHeaderCt.ddLock) {
                // Firefox doesn't check the current target in a within check.
                // Therefore we check the target directly and then within (ancestors)
                if (me.triggerEl && (e.target === me.triggerEl.dom || t === me.triggerEl.dom || e.within(me.triggerEl))) {
                    ownerHeaderCt.onHeaderTriggerClick(me, e, t);
                // if its not on the left hand edge, sort
                } else if (e.getKey() || (!me.isOnLeftEdge(e) && !me.isOnRightEdge(e))) {
                    me.toggleSortState();
                    ownerHeaderCt.onHeaderClick(me, e, t);
                }
            }
        },

        /**
         * @private
         * Process UI events from the view. The owning TablePanel calls this method, relaying events from the TableView
         * @param {String} type Event type, eg 'click'
         * @param {Ext.view.Table} view TableView Component
         * @param {HTMLElement} cell Cell HtmlElement the event took place within
         * @param {Number} recordIndex Index of the associated Store Model (-1 if none)
         * @param {Number} cellIndex Cell index within the row
         * @param {Ext.EventObject} e Original event
         */
        processEvent: function(type, view, cell, recordIndex, cellIndex, e) {
            return this.fireEvent.apply(this, arguments);
        },

        toggleSortState: function() {
            var me = this,
                idx,
                nextIdx;

            if (me.sortable) {
                idx = Ext.Array.indexOf(me.possibleSortStates, me.sortState);

                nextIdx = (idx + 1) % me.possibleSortStates.length;
                me.setSortState(me.possibleSortStates[nextIdx]);
            }
        },

        doSort: function(state) {
            var ds = this.up('tablepanel').store;
            ds.sort({
                property: this.getSortParam(),
                direction: state
            });
        },

        /**
         * Returns the parameter to sort upon when sorting this header. By default this returns the dataIndex and will not
         * need to be overriden in most cases.
         * @return {String}
         */
        getSortParam: function() {
            return this.dataIndex;
        },

        //setSortState: function(state, updateUI) {
        //setSortState: function(state, doSort) {
        setSortState: function(state, skipClear, initial) {
            var me = this,
                colSortClsPrefix = Ext.baseCSSPrefix + 'column-header-sort-',
                ascCls = colSortClsPrefix + 'ASC',
                descCls = colSortClsPrefix + 'DESC',
                nullCls = colSortClsPrefix + 'null',
                ownerHeaderCt = me.getOwnerHeaderCt(),
                oldSortState = me.sortState;

            if (oldSortState !== state && me.getSortParam()) {
                me.addCls(colSortClsPrefix + state);
                // don't trigger a sort on the first time, we just want to update the UI
                if (state && !initial) {
                    me.doSort(state);
                }
                switch (state) {
                    case 'DESC':
                        me.removeCls([ascCls, nullCls]);
                        break;
                    case 'ASC':
                        me.removeCls([descCls, nullCls]);
                        break;
                    case null:
                        me.removeCls([ascCls, descCls]);
                        break;
                }
                if (ownerHeaderCt && !me.triStateSort && !skipClear) {
                    ownerHeaderCt.clearOtherSortStates(me);
                }
                me.sortState = state;
                // we only want to fire the event if we have a null state when using triStateSort
                if (me.triStateSort || state != null) {
                    ownerHeaderCt.fireEvent('sortchange', ownerHeaderCt, me, state);
                }
            }
        },

        hide: function(fromOwner) {
            var me = this,
                ownerHeaderCt = me.getOwnerHeaderCt(),
                owner = me.ownerCt,
                ownerIsGroup = owner.isGroupHeader,
                item, items, len, i;

            // owner is a group, hide call didn't come from the owner
            if (ownerIsGroup && !fromOwner) {
                items = owner.query('>:not([hidden])');
                // only have one item that isn't hidden, this is it.
                if (items.length === 1 && items[0] == me) {
                    me.ownerCt.hide();
                    return;
                }
            }

            Ext.suspendLayouts();

            if (me.isGroupHeader) {
                items = me.items.items;
                for (i = 0, len = items.length; i < len; i++) {
                    item = items[i];
                    if (!item.hidden) {
                        item.hide(true);
                    }
                }
            }

            me.callParent();
            // Notify owning HeaderContainer
            ownerHeaderCt.onHeaderHide(me);

            Ext.resumeLayouts(true);
        },

        show: function(fromOwner, fromChild) {
            var me = this,
                ownerCt = me.ownerCt,
                items,
                len, i,
                item;

            Ext.suspendLayouts();

            // If a sub header, ensure that the group header is visible
            if (me.isSubHeader && ownerCt.hidden) {
                ownerCt.show(false, true);
            }

            me.callParent(arguments);

            // If we've just shown a group with all its sub headers hidden, then show all its sub headers
            if (me.isGroupHeader && fromChild !== true && !me.query(':not([hidden])').length) {
                items = me.query('>*');
                for (i = 0, len = items.length; i < len; i++) {
                    item = items[i];
                    if (item.hidden) {
                        item.show(true);
                    }
                }
            }

            Ext.resumeLayouts(true);

            // Notify owning HeaderContainer AFTER layout has been flushed so that header and headerCt widths are all correct
            ownerCt = me.getOwnerHeaderCt();
            if (ownerCt) {
                ownerCt.onHeaderShow(me);
            }
        },

        getDesiredWidth: function() {
            var me = this;
            if (me.rendered && me.componentLayout && me.componentLayout.lastComponentSize) {
                // headers always have either a width or a flex
                // because HeaderContainer sets a defaults width
                // therefore we can ignore the natural width
                // we use the componentLayout's tracked width so that
                // we can calculate the desired width when rendered
                // but not visible because its being obscured by a layout
                return me.componentLayout.lastComponentSize.width;
            // Flexed but yet to be rendered this could be the case
            // where a HeaderContainer and Headers are simply used as data
            // structures and not rendered.
            }
            else if (me.flex) {
                // this is going to be wrong, the defaultWidth
                return me.width;
            }
            else {
                return me.width;
            }
        },

        getCellSelector: function() {
            return '.' + Ext.baseCSSPrefix + 'grid-cell-' + this.getItemId();
        },

        getCellInnerSelector: function() {
            return this.getCellSelector() + ' .' + Ext.baseCSSPrefix + 'grid-cell-inner';
        },

        isOnLeftEdge: function(e) {
            return (e.getXY()[0] - this.el.getLeft() <= this.handleWidth);
        },

        isOnRightEdge: function(e) {
            return (this.el.getRight() - e.getXY()[0] <= this.handleWidth);
        }

        // intentionally omit getEditor and setEditor definitions bc we applyIf into columns
        // when the editing plugin is injected

        /**
         * @method getEditor
         * Retrieves the editing field for editing associated with this header. Returns false if there is no field
         * associated with the Header the method will return false. If the field has not been instantiated it will be
         * created. Note: These methods only has an implementation if a Editing plugin has been enabled on the grid.
         * @param {Object} record The {@link Ext.data.Model Model} instance being edited.
         * @param {Object} defaultField An object representing a default field to be created
         * @return {Ext.form.field.Field} field
         */
        /**
         * @method setEditor
         * Sets the form field to be used for editing. Note: This method only has an implementation if an Editing plugin has
         * been enabled on the grid.
         * @param {Object} field An object representing a field to be created. If no xtype is specified a 'textfield' is
         * assumed.
         */
    });