The source code

    /**
     * @class Ext.grid.GridView
     * @extends Ext.util.Observable
     * This class encapsulates the user interface of an {@link Ext.grid.GridPanel}.
     * Methods of this class may be used to access user interface elements to enable
     * special display effects. Do not change the DOM structure of the user interface.
     * This class does not provide ways to manipulate the underlying data. The data
     * model of a Grid is held in an {@link Ext.data.Store}.
     * @constructor
     * @param {Object} config
     */
    Ext.grid.GridView = function(config){
        Ext.apply(this, config);
        // These events are only used internally by the grid components
        this.addEvents(
            /**
             * @event beforerowremoved
             * Internal UI Event. Fired before a row is removed.
             * @param {Ext.grid.GridView} view
             * @param {Number} rowIndex The index of the row to be removed.
             * @param {Ext.data.Record} record The Record to be removed
             */
            "beforerowremoved",
            /**
             * @event beforerowsinserted
             * Internal UI Event. Fired before rows are inserted.
             * @param {Ext.grid.GridView} view
             * @param {Number} firstRow The index of the first row to be inserted.
             * @param {Number} lastRow The index of the last row to be inserted.
             */
            "beforerowsinserted",
            /**
             * @event beforerefresh
             * Internal UI Event. Fired before the view is refreshed.
             * @param {Ext.grid.GridView} view
             */
            "beforerefresh",
            /**
             * @event rowremoved
             * Internal UI Event. Fired after a row is removed.
             * @param {Ext.grid.GridView} view
             * @param {Number} rowIndex The index of the row that was removed.
             * @param {Ext.data.Record} record The Record that was removed
             */
            "rowremoved",
            /**
             * @event rowsinserted
             * Internal UI Event. Fired after rows are inserted.
             * @param {Ext.grid.GridView} view
             * @param {Number} firstRow The index of the first inserted.
             * @param {Number} lastRow The index of the last row inserted.
             */
            "rowsinserted",
            /**
             * @event rowupdated
             * Internal UI Event. Fired after a row has been updated.
             * @param {Ext.grid.GridView} view
             * @param {Number} firstRow The index of the row updated.
             * @param {Ext.data.record} record The Record backing the row updated.
             */
            "rowupdated",
            /**
             * @event refresh
             * Internal UI Event. Fired after the GridView's body has been refreshed.
             * @param {Ext.grid.GridView} view
             */
            "refresh"
        );
        Ext.grid.GridView.superclass.constructor.call(this);
    };

    Ext.extend(Ext.grid.GridView, Ext.util.Observable, {
        /**
         * Override this function to apply custom CSS classes to rows during rendering.  You can also supply custom
         * parameters to the row template for the current row to customize how it is rendered using the rowParams
         * parameter.  This function should return the CSS class name (or empty string '' for none) that will be added
         * to the row's wrapping div.  To apply multiple class names, simply return them space-delimited within the string
         * (e.g., 'my-class another-class'). Example usage:

    viewConfig: {
        forceFit: true,
        showPreview: true, // custom property
        enableRowBody: true, // required to create a second, full-width row to show expanded Record data
        getRowClass: function(record, rowIndex, rp, ds){ // rp = rowParams
            if(this.showPreview){
                rp.body = '<p>'+record.data.excerpt+'</p>';
                return 'x-grid3-row-expanded';
            }
            return 'x-grid3-row-collapsed';
        }
    },

         * @param {Record} record The {@link Ext.data.Record} corresponding to the current row.
         * @param {Number} index The row index.
         * @param {Object} rowParams A config object that is passed to the row template during rendering that allows
         * customization of various aspects of a grid row.
         * If {@link #enableRowBody} is configured true, then the following properties may be set
         * by this function, and will be used to render a full-width expansion row below each grid row:
         *
         * body : String An HTML fragment to be used as the expansion row's body content (defaults to '').
         * bodyStyle : String A CSS style specification that will be applied to the expansion row's <tr> element. (defaults to '').
         *
         * The following property will be passed in, and may be appended to:
         *
         * tstyle : String A CSS style specification that willl be applied to the <table> element which encapsulates
         * both the standard grid row, and any expansion row.
         *
         * @param {Store} store The {@link Ext.data.Store} this grid is bound to
         * @method getRowClass
         * @return {String} a CSS class name to add to the row.
         */
        /**
         * @cfg {Boolean} enableRowBody True to add a second TR element per row that can be used to provide a row body
         * that spans beneath the data row.  Use the {@link #getRowClass} method's rowParams config to customize the row body.
         */
        /**
         * @cfg {String} emptyText Default text (html tags are accepted) to display in the grid body when no rows
         * are available (defaults to ''). This value will be used to update the {@link #mainBody}:

        this.mainBody.update('<div class="x-grid-empty">' + this.emptyText + '</div>');

         */
        /**
         * @cfg {Boolean} headersDisabled True to disable the grid column headers (defaults to false).
         * Use the {@link Ext.grid.ColumnModel ColumnModel} {@link Ext.grid.ColumnModel#menuDisabled menuDisabled}
         * config to disable the menu for individual columns.  While this config is true the
         * following will be disabled:
         * clicking on header to sort
         * the trigger to reveal the menu.
         *
         */
        /**
         * A customized implementation of a {@link Ext.dd.DragZone DragZone} which provides default implementations
         * of the template methods of DragZone to enable dragging of the selected rows of a GridPanel.
         * See {@link Ext.grid.GridDragZone} for details.
         * This will only be present:
         * if the owning GridPanel was configured with {@link Ext.grid.GridPanel#enableDragDrop enableDragDrop}: true.
         * after the owning GridPanel has been rendered.
         *
         * @property dragZone
         * @type {Ext.grid.GridDragZone}
         */
        /**
         * @cfg {Boolean} deferEmptyText True to defer {@link #emptyText} being applied until the store's
         * first load (defaults to true).
         */
        deferEmptyText : true,
        /**
         * @cfg {Number} scrollOffset The amount of space to reserve for the vertical scrollbar
         * (defaults to 19 pixels).
         */
        scrollOffset : 19,
        /**
         * @cfg {Boolean} autoFill
         * Defaults to false.  Specify true to have the column widths re-proportioned
         * when the grid is initially rendered.  The
         * {@link Ext.grid.Column#width initially configured width} of each column will be adjusted
         * to fit the grid width and prevent horizontal scrolling. If columns are later resized (manually
         * or programmatically), the other columns in the grid will not be resized to fit the grid width.
         * See {@link #forceFit} also.
         */
        autoFill : false,
        /**
         * @cfg {Boolean} forceFit
         * Defaults to false.  Specify true to have the column widths re-proportioned
         * at all times.  The {@link Ext.grid.Column#width initially configured width} of each
         * column will be adjusted to fit the grid width and prevent horizontal scrolling. If columns are
         * later resized (manually or programmatically), the other columns in the grid will be resized
         * to fit the grid width. See {@link #autoFill} also.
         */
        forceFit : false,
        /**
         * @cfg {Array} sortClasses The CSS classes applied to a header when it is sorted. (defaults to ["sort-asc", "sort-desc"])
         */
        sortClasses : ["sort-asc", "sort-desc"],
        /**
         * @cfg {String} sortAscText The text displayed in the "Sort Ascending" menu item (defaults to "Sort Ascending")
         */
        sortAscText : "Sort Ascending",
        /**
         * @cfg {String} sortDescText The text displayed in the "Sort Descending" menu item (defaults to "Sort Descending")
         */
        sortDescText : "Sort Descending",
        /**
         * @cfg {String} columnsText The text displayed in the "Columns" menu item (defaults to "Columns")
         */
        columnsText : "Columns",

        /**
         * @cfg {String} selectedRowClass The CSS class applied to a selected row (defaults to "x-grid3-row-selected"). An
         * example overriding the default styling:

        .x-grid3-row-selected {background-color: yellow;}

         * Note that this only controls the row, and will not do anything for the text inside it.  To style inner
         * facets (like text) use something like:

        .x-grid3-row-selected .x-grid3-cell-inner {
            color: #FFCC00;
        }

         * @type String
         */
        selectedRowClass : "x-grid3-row-selected",

        // private
        borderWidth : 2,
        tdClass : 'x-grid3-cell',
        hdCls : 'x-grid3-hd',
        markDirty : true,

        /**
         * @cfg {Number} cellSelectorDepth The number of levels to search for cells in event delegation (defaults to 4)
         */
        cellSelectorDepth : 4,
        /**
         * @cfg {Number} rowSelectorDepth The number of levels to search for rows in event delegation (defaults to 10)
         */
        rowSelectorDepth : 10,

        /**
         * @cfg {String} cellSelector The selector used to find cells internally (defaults to 'td.x-grid3-cell')
         */
        cellSelector : 'td.x-grid3-cell',
        /**
         * @cfg {String} rowSelector The selector used to find rows internally (defaults to 'div.x-grid3-row')
         */
        rowSelector : 'div.x-grid3-row',

        // private
        firstRowCls: 'x-grid3-row-first',
        lastRowCls: 'x-grid3-row-last',
        rowClsRe: /(?:^|\s+)x-grid3-row-(first|last|alt)(?:\s+|$)/g,

        /* -------------------------------- UI Specific ----------------------------- */

        // private
        initTemplates : function(){
            var ts = this.templates || {};
            if(!ts.master){
                ts.master = new Ext.Template(
                        '',
                            '',
                                '{header}',
                                '{body}',
                            '',
                            ' ',
                            ' ',
                        ''
                        );
            }

            if(!ts.header){
                ts.header = new Ext.Template(
                        '',
                        '{cells}',
                        ''
                        );
            }

            if(!ts.hcell){
                ts.hcell = new Ext.Template(
                        '', this.grid.enableHdMenu ? '' : '',
                        '{value}',
                        ''
                        );
            }

            if(!ts.body){
                ts.body = new Ext.Template('{rows}');
            }

            if(!ts.row){
                ts.row = new Ext.Template(
                        '',
                        '{cells}',
                        (this.enableRowBody ? '{body}' : ''),
                        ''
                        );
            }

            if(!ts.cell){
                ts.cell = new Ext.Template(
                        '',
                        '{value}',
                        ''
                        );
            }

            for(var k in ts){
                var t = ts[k];
                if(t && Ext.isFunction(t.compile) && !t.compiled){
                    t.disableFormats = true;
                    t.compile();
                }
            }

            this.templates = ts;
            this.colRe = new RegExp("x-grid3-td-([^\\s]+)", "");
        },

        // private
        fly : function(el){
            if(!this._flyweight){
                this._flyweight = new Ext.Element.Flyweight(document.body);
            }
            this._flyweight.dom = el;
            return this._flyweight;
        },

        // private
        getEditorParent : function(){
            return this.scroller.dom;
        },

        // private
        initElements : function(){
            var E = Ext.Element;

            var el = this.grid.getGridEl().dom.firstChild;
            var cs = el.childNodes;

            this.el = new E(el);

            this.mainWrap = new E(cs[0]);
            this.mainHd = new E(this.mainWrap.dom.firstChild);

            if(this.grid.hideHeaders){
                this.mainHd.setDisplayed(false);
            }

            this.innerHd = this.mainHd.dom.firstChild;
            this.scroller = new E(this.mainWrap.dom.childNodes[1]);
            if(this.forceFit){
                this.scroller.setStyle('overflow-x', 'hidden');
            }
            /**
             * Read-only. The GridView's body Element which encapsulates all rows in the Grid.
             * This {@link Ext.Element Element} is only available after the GridPanel has been rendered.
             * @type Ext.Element
             * @property mainBody
             */
            this.mainBody = new E(this.scroller.dom.firstChild);

            this.focusEl = new E(this.scroller.dom.childNodes[1]);
            this.focusEl.swallowEvent("click", true);

            this.resizeMarker = new E(cs[1]);
            this.resizeProxy = new E(cs[2]);
        },

        // private
        getRows : function(){
            return this.hasRows() ? this.mainBody.dom.childNodes : [];
        },

        // finder methods, used with delegation

        // private
        findCell : function(el){
            if(!el){
                return false;
            }
            return this.fly(el).findParent(this.cellSelector, this.cellSelectorDepth);
        },

        /**
         * Return the index of the grid column which contains the passed HTMLElement.
         * See also {@link #findRowIndex}
         * @param {HTMLElement} el The target element
         * @return The column index, or false if the target element is not within a row of this GridView.
         */
        findCellIndex : function(el, requiredCls){
            var cell = this.findCell(el);
            if(cell && (!requiredCls || this.fly(cell).hasClass(requiredCls))){
                return this.getCellIndex(cell);
            }
            return false;
        },

        // private
        getCellIndex : function(el){
            if(el){
                var m = el.className.match(this.colRe);
                if(m && m[1]){
                    return this.cm.getIndexById(m[1]);
                }
            }
            return false;
        },

        // private
        findHeaderCell : function(el){
            var cell = this.findCell(el);
            return cell && this.fly(cell).hasClass(this.hdCls) ? cell : null;
        },

        // private
        findHeaderIndex : function(el){
            return this.findCellIndex(el, this.hdCls);
        },

        /**
         * Return the HtmlElement representing the grid row which contains the passed element.
         * @param {HTMLElement} el The target HTMLElement
         * @return The row element, or null if the target element is not within a row of this GridView.
         */
        findRow : function(el){
            if(!el){
                return false;
            }
            return this.fly(el).findParent(this.rowSelector, this.rowSelectorDepth);
        },

        /**
         * Return the index of the grid row which contains the passed HTMLElement.
         * See also {@link #findCellIndex}
         * @param {HTMLElement} el The target HTMLElement
         * @return The row index, or false if the target element is not within a row of this GridView.
         */
        findRowIndex : function(el){
            var r = this.findRow(el);
            return r ? r.rowIndex : false;
        },

        // getter methods for fetching elements dynamically in the grid

        /**
         * Return the <div> HtmlElement which represents a Grid row for the specified index.
         * @param {Number} index The row index
         * @return {HtmlElement} The div element.
         */
        getRow : function(row){
            return this.getRows()[row];
        },

        /**
         * Returns the grid's <td> HtmlElement at the specified coordinates.
         * @param {Number} row The row index in which to find the cell.
         * @param {Number} col The column index of the cell.
         * @return {HtmlElement} The td at the specified coordinates.
         */
        getCell : function(row, col){
            return this.getRow(row).getElementsByTagName('td')[col];
        },

        /**
         * Return the <td> HtmlElement which represents the Grid's header cell for the specified column index.
         * @param {Number} index The column index
         * @return {HtmlElement} The td element.
         */
        getHeaderCell : function(index){
          return this.mainHd.dom.getElementsByTagName('td')[index];
        },

        // manipulating elements

        // private - use getRowClass to apply custom row classes
        addRowClass : function(row, cls){
            var r = this.getRow(row);
            if(r){
                this.fly(r).addClass(cls);
            }
        },

        // private
        removeRowClass : function(row, cls){
            var r = this.getRow(row);
            if(r){
                this.fly(r).removeClass(cls);
            }
        },

        // private
        removeRow : function(row){
            Ext.removeNode(this.getRow(row));
            this.syncFocusEl(row);
        },

        // private
        removeRows : function(firstRow, lastRow){
            var bd = this.mainBody.dom;
            for(var rowIndex = firstRow; rowIndex <= lastRow; rowIndex++){
                Ext.removeNode(bd.childNodes[firstRow]);
            }
            this.syncFocusEl(firstRow);
        },

        // scrolling stuff

        // private
        getScrollState : function(){
            var sb = this.scroller.dom;
            return {left: sb.scrollLeft, top: sb.scrollTop};
        },

        // private
        restoreScroll : function(state){
            var sb = this.scroller.dom;
            sb.scrollLeft = state.left;
            sb.scrollTop = state.top;
        },

        /**
         * Scrolls the grid to the top
         */
        scrollToTop : function(){
            this.scroller.dom.scrollTop = 0;
            this.scroller.dom.scrollLeft = 0;
        },

        // private
        syncScroll : function(){
          this.syncHeaderScroll();
          var mb = this.scroller.dom;
            this.grid.fireEvent("bodyscroll", mb.scrollLeft, mb.scrollTop);
        },

        // private
        syncHeaderScroll : function(){
            var mb = this.scroller.dom;
            this.innerHd.scrollLeft = mb.scrollLeft;
            this.innerHd.scrollLeft = mb.scrollLeft; // second time for IE (1/2 time first fails, other browsers ignore)
        },

        // private
        updateSortIcon : function(col, dir){
            var sc = this.sortClasses;
            var hds = this.mainHd.select('td').removeClass(sc);
            hds.item(col).addClass(sc[dir == "DESC" ? 1 : 0]);
        },

        // private
        updateAllColumnWidths : function(){
            var tw = this.getTotalWidth(),
                clen = this.cm.getColumnCount(),
                ws = [],
                len,
                i;
            for(i = 0; i < clen; i++){
                ws[i] = this.getColumnWidth(i);
            }
            this.innerHd.firstChild.style.width = this.getOffsetWidth();
            this.innerHd.firstChild.firstChild.style.width = tw;
            this.mainBody.dom.style.width = tw;
            for(i = 0; i < clen; i++){
                var hd = this.getHeaderCell(i);
                hd.style.width = ws[i];
            }

            var ns = this.getRows(), row, trow;
            for(i = 0, len = ns.length; i < len; i++){
                row = ns[i];
                row.style.width = tw;
                if(row.firstChild){
                    row.firstChild.style.width = tw;
                    trow = row.firstChild.rows[0];
                    for (var j = 0; j < clen; j++) {
                       trow.childNodes[j].style.width = ws[j];
                    }
                }
            }

            this.onAllColumnWidthsUpdated(ws, tw);
        },

        // private
        updateColumnWidth : function(col, width){
            var w = this.getColumnWidth(col);
            var tw = this.getTotalWidth();
            this.innerHd.firstChild.style.width = this.getOffsetWidth();
            this.innerHd.firstChild.firstChild.style.width = tw;
            this.mainBody.dom.style.width = tw;
            var hd = this.getHeaderCell(col);
            hd.style.width = w;

            var ns = this.getRows(), row;
            for(var i = 0, len = ns.length; i < len; i++){
                row = ns[i];
                row.style.width = tw;
                if(row.firstChild){
                    row.firstChild.style.width = tw;
                    row.firstChild.rows[0].childNodes[col].style.width = w;
                }
            }

            this.onColumnWidthUpdated(col, w, tw);
        },

        // private
        updateColumnHidden : function(col, hidden){
            var tw = this.getTotalWidth();
            this.innerHd.firstChild.style.width = this.getOffsetWidth();
            this.innerHd.firstChild.firstChild.style.width = tw;
            this.mainBody.dom.style.width = tw;
            var display = hidden ? 'none' : '';

            var hd = this.getHeaderCell(col);
            hd.style.display = display;

            var ns = this.getRows(), row;
            for(var i = 0, len = ns.length; i < len; i++){
                row = ns[i];
                row.style.width = tw;
                if(row.firstChild){
                    row.firstChild.style.width = tw;
                    row.firstChild.rows[0].childNodes[col].style.display = display;
                }
            }

            this.onColumnHiddenUpdated(col, hidden, tw);
            delete this.lastViewWidth; // force recalc
            this.layout();
        },

        // private
        doRender : function(cs, rs, ds, startRow, colCount, stripe){
            var ts = this.templates, ct = ts.cell, rt = ts.row, last = colCount-1;
            var tstyle = 'width:'+this.getTotalWidth()+';';
            // buffers
            var buf = [], cb, c, p = {}, rp = {tstyle: tstyle}, r;
            for(var j = 0, len = rs.length; j < len; j++){
                r = rs[j]; cb = [];
                var rowIndex = (j+startRow);
                for(var i = 0; i < colCount; i++){
                    c = cs[i];
                    p.id = c.id;
                    p.css = i === 0 ? 'x-grid3-cell-first ' : (i == last ? 'x-grid3-cell-last ' : '');
                    p.attr = p.cellAttr = "";
                    p.value = c.renderer(r.data[c.name], p, r, rowIndex, i, ds);
                    p.style = c.style;
                    if(Ext.isEmpty(p.value)){
                        p.value = " ";
                    }
                    if(this.markDirty && r.dirty && Ext.isDefined(r.modified[c.name])){
                        p.css += ' x-grid3-dirty-cell';
                    }
                    cb[cb.length] = ct.apply(p);
                }
                var alt = [];
                if(stripe && ((rowIndex+1) % 2 === 0)){
                    alt[0] = "x-grid3-row-alt";
                }
                if(r.dirty){
                    alt[1] = " x-grid3-dirty-row";
                }
                rp.cols = colCount;
                if(this.getRowClass){
                    alt[2] = this.getRowClass(r, rowIndex, rp, ds);
                }
                rp.alt = alt.join(" ");
                rp.cells = cb.join("");
                buf[buf.length] =  rt.apply(rp);
            }
            return buf.join("");
        },

        // private
        processRows : function(startRow, skipStripe){
            if(!this.ds || this.ds.getCount() < 1){
                return;
            }
            var rows = this.getRows();
            skipStripe = skipStripe || !this.grid.stripeRows;
            startRow = startRow || 0;
            Ext.each(rows, function(row, idx){
                row.rowIndex = idx;
                row.className = row.className.replace(this.rowClsRe, ' ');
                if (!skipStripe && (idx + 1) % 2 === 0) {
                    row.className += ' x-grid3-row-alt';
                }
            });
            // add first/last-row classes
            if(startRow === 0){
                Ext.fly(rows[0]).addClass(this.firstRowCls);
            }
            Ext.fly(rows[rows.length - 1]).addClass(this.lastRowCls);
        },

        afterRender : function(){
            if(!this.ds || !this.cm){
                return;
            }
            this.mainBody.dom.innerHTML = this.renderRows() || ' ';
            this.processRows(0, true);

            if(this.deferEmptyText !== true){
                this.applyEmptyText();
            }
        },

        // private
        renderUI : function(){

            var header = this.renderHeaders();
            var body = this.templates.body.apply({rows:' '});

            var html = this.templates.master.apply({
                body: body,
                header: header,
                ostyle: 'width:'+this.getOffsetWidth()+';',
                bstyle: 'width:'+this.getTotalWidth()+';'
            });

            var g = this.grid;

            g.getGridEl().dom.innerHTML = html;

            this.initElements();

            // get mousedowns early
            Ext.fly(this.innerHd).on("click", this.handleHdDown, this);
            this.mainHd.on({
                scope: this,
                mouseover: this.handleHdOver,
                mouseout: this.handleHdOut,
                mousemove: this.handleHdMove
            });

            this.scroller.on('scroll', this.syncScroll,  this);
            if(g.enableColumnResize !== false){
                this.splitZone = new Ext.grid.GridView.SplitDragZone(g, this.mainHd.dom);
            }

            if(g.enableColumnMove){
                this.columnDrag = new Ext.grid.GridView.ColumnDragZone(g, this.innerHd);
                this.columnDrop = new Ext.grid.HeaderDropZone(g, this.mainHd.dom);
            }

            if(g.enableHdMenu !== false){
                this.hmenu = new Ext.menu.Menu({id: g.id + "-hctx"});
                this.hmenu.add(
                    {itemId:"asc", text: this.sortAscText, cls: "xg-hmenu-sort-asc"},
                    {itemId:"desc", text: this.sortDescText, cls: "xg-hmenu-sort-desc"}
                );
                if(g.enableColumnHide !== false){
                    this.colMenu = new Ext.menu.Menu({id:g.id + "-hcols-menu"});
                    this.colMenu.on({
                        scope: this,
                        beforeshow: this.beforeColMenuShow,
                        itemclick: this.handleHdMenuClick
                    });
                    this.hmenu.add('-', {
                        itemId:"columns",
                        hideOnClick: false,
                        text: this.columnsText,
                        menu: this.colMenu,
                        iconCls: 'x-cols-icon'
                    });
                }
                this.hmenu.on("itemclick", this.handleHdMenuClick, this);
            }

            if(g.trackMouseOver){
                this.mainBody.on({
                    scope: this,
                    mouseover: this.onRowOver,
                    mouseout: this.onRowOut
                });
            }

            if(g.enableDragDrop || g.enableDrag){
                this.dragZone = new Ext.grid.GridDragZone(g, {
                    ddGroup : g.ddGroup || 'GridDD'
                });
            }

            this.updateHeaderSortState();

        },

        // private
        layout : function(){
            if(!this.mainBody){
                return; // not rendered
            }
            var g = this.grid;
            var c = g.getGridEl();
            var csize = c.getSize(true);
            var vw = csize.width;

            if(!g.hideHeaders && (vw < 20 || csize.height < 20)){ // display: none?
                return;
            }

            if(g.autoHeight){
                this.scroller.dom.style.overflow = 'visible';
                if(Ext.isWebKit){
                    this.scroller.dom.style.position = 'static';
                }
            }else{
                this.el.setSize(csize.width, csize.height);

                var hdHeight = this.mainHd.getHeight();
                var vh = csize.height - (hdHeight);

                this.scroller.setSize(vw, vh);
                if(this.innerHd){
                    this.innerHd.style.width = (vw)+'px';
                }
            }
            if(this.forceFit){
                if(this.lastViewWidth != vw){
                    this.fitColumns(false, false);
                    this.lastViewWidth = vw;
                }
            }else {
                this.autoExpand();
                this.syncHeaderScroll();
            }
            this.onLayout(vw, vh);
        },

        // template functions for subclasses and plugins
        // these functions include precalculated values
        onLayout : function(vw, vh){
            // do nothing
        },

        onColumnWidthUpdated : function(col, w, tw){
            //template method
        },

        onAllColumnWidthsUpdated : function(ws, tw){
            //template method
        },

        onColumnHiddenUpdated : function(col, hidden, tw){
            // template method
        },

        updateColumnText : function(col, text){
            // template method
        },

        afterMove : function(colIndex){
            // template method
        },

        /* ----------------------------------- Core Specific -------------------------------------------*/
        // private
        init : function(grid){
            this.grid = grid;

            this.initTemplates();
            this.initData(grid.store, grid.colModel);
            this.initUI(grid);
        },

        // private
        getColumnId : function(index){
          return this.cm.getColumnId(index);
        },

        // private
        getOffsetWidth : function() {
            return (this.cm.getTotalWidth() + this.scrollOffset) + 'px';
        },

        // private
        renderHeaders : function(){
            var cm = this.cm,
                ts = this.templates,
                ct = ts.hcell,
                cb = [],
                p = {},
                len = cm.getColumnCount(),
                last = len - 1;

            for(var i = 0; i < len; i++){
                p.id = cm.getColumnId(i);
                p.value = cm.getColumnHeader(i) || "";
                p.style = this.getColumnStyle(i, true);
                p.tooltip = this.getColumnTooltip(i);
                p.css = i === 0 ? 'x-grid3-cell-first ' : (i == last ? 'x-grid3-cell-last ' : '');
                if(cm.config[i].align == 'right'){
                    p.istyle = 'padding-right:16px';
                } else {
                    delete p.istyle;
                }
                cb[cb.length] = ct.apply(p);
            }
            return ts.header.apply({cells: cb.join(""), tstyle:'width:'+this.getTotalWidth()+';'});
        },

        // private
        getColumnTooltip : function(i){
            var tt = this.cm.getColumnTooltip(i);
            if(tt){
                if(Ext.QuickTips.isEnabled()){
                    return 'ext:qtip="'+tt+'"';
                }else{
                    return 'title="'+tt+'"';
                }
            }
            return "";
        },

        // private
        beforeUpdate : function(){
            this.grid.stopEditing(true);
        },

        // private
        updateHeaders : function(){
            this.innerHd.firstChild.innerHTML = this.renderHeaders();
            this.innerHd.firstChild.style.width = this.getOffsetWidth();
            this.innerHd.firstChild.firstChild.style.width = this.getTotalWidth();
        },

        /**
         * Focuses the specified row.
         * @param {Number} row The row index
         */
        focusRow : function(row){
            this.focusCell(row, 0, false);
        },

        /**
         * Focuses the specified cell.
         * @param {Number} row The row index
         * @param {Number} col The column index
         */
        focusCell : function(row, col, hscroll){
            this.syncFocusEl(this.ensureVisible(row, col, hscroll));
            if(Ext.isGecko){
                this.focusEl.focus();
            }else{
                this.focusEl.focus.defer(1, this.focusEl);
            }
        },

        resolveCell : function(row, col, hscroll){
            if(!Ext.isNumber(row)){
                row = row.rowIndex;
            }
            if(!this.ds){
                return null;
            }
            if(row < 0 || row >= this.ds.getCount()){
                return null;
            }
            col = (col !== undefined ? col : 0);

            var rowEl = this.getRow(row),
                cm = this.cm,
                colCount = cm.getColumnCount(),
                cellEl;
            if(!(hscroll === false && col === 0)){
                while(col < colCount && cm.isHidden(col)){
                    col++;
                }
                cellEl = this.getCell(row, col);
            }

            return {row: rowEl, cell: cellEl};
        },

        getResolvedXY : function(resolved){
            if(!resolved){
                return null;
            }
            var s = this.scroller.dom, c = resolved.cell, r = resolved.row;
            return c ? Ext.fly(c).getXY() : [this.el.getX(), Ext.fly(r).getY()];
        },

        syncFocusEl : function(row, col, hscroll){
            var xy = row;
            if(!Ext.isArray(xy)){
                row = Math.min(row, Math.max(0, this.getRows().length-1));
                xy = this.getResolvedXY(this.resolveCell(row, col, hscroll));
            }
            this.focusEl.setXY(xy||this.scroller.getXY());
        },

        ensureVisible : function(row, col, hscroll){
            var resolved = this.resolveCell(row, col, hscroll);
            if(!resolved || !resolved.row){
                return;
            }

            var rowEl = resolved.row,
                cellEl = resolved.cell,
                c = this.scroller.dom,
                ctop = 0,
                p = rowEl,
                stop = this.el.dom;

            while(p && p != stop){
                ctop += p.offsetTop;
                p = p.offsetParent;
            }
            ctop -= this.mainHd.dom.offsetHeight;

            var cbot = ctop + rowEl.offsetHeight,
                ch = c.clientHeight,
                sbot = stop + ch;

            stop = parseInt(c.scrollTop, 10);

            if(ctop < stop){
              c.scrollTop = ctop;
            }else if(cbot > sbot){
                c.scrollTop = cbot-ch;
            }

            if(hscroll !== false){
                var cleft = parseInt(cellEl.offsetLeft, 10);
                var cright = cleft + cellEl.offsetWidth;

                var sleft = parseInt(c.scrollLeft, 10);
                var sright = sleft + c.clientWidth;
                if(cleft < sleft){
                    c.scrollLeft = cleft;
                }else if(cright > sright){
                    c.scrollLeft = cright-c.clientWidth;
                }
            }
            return this.getResolvedXY(resolved);
        },

        // private
        insertRows : function(dm, firstRow, lastRow, isUpdate){
            var last = dm.getCount() - 1;
            if(!isUpdate && firstRow === 0 && lastRow >= last){
                this.refresh();
            }else{
                if(!isUpdate){
                    this.fireEvent("beforerowsinserted", this, firstRow, lastRow);
                }
                var html = this.renderRows(firstRow, lastRow),
                    before = this.getRow(firstRow);
                if(before){
                    if(firstRow === 0){
                        Ext.fly(this.getRow(0)).removeClass(this.firstRowCls);
                    }
                    Ext.DomHelper.insertHtml('beforeBegin', before, html);
                }else{
                    var r = this.getRow(last - 1);
                    if(r){
                        Ext.fly(r).removeClass(this.lastRowCls);
                    }
                    Ext.DomHelper.insertHtml('beforeEnd', this.mainBody.dom, html);
                }
                if(!isUpdate){
                    this.fireEvent("rowsinserted", this, firstRow, lastRow);
                    this.processRows(firstRow);
                }else if(firstRow === 0 || firstRow >= last){
                    //ensure first/last row is kept after an update.
                    Ext.fly(this.getRow(firstRow)).addClass(firstRow === 0 ? this.firstRowCls : this.lastRowCls);
                }
            }
            this.syncFocusEl(firstRow);
        },

        // private
        deleteRows : function(dm, firstRow, lastRow){
            if(dm.getRowCount()<1){
                this.refresh();
            }else{
                this.fireEvent("beforerowsdeleted", this, firstRow, lastRow);

                this.removeRows(firstRow, lastRow);

                this.processRows(firstRow);
                this.fireEvent("rowsdeleted", this, firstRow, lastRow);
            }
        },

        // private
        getColumnStyle : function(col, isHeader){
            var style = !isHeader ? (this.cm.config[col].css || '') : '';
            style += 'width:'+this.getColumnWidth(col)+';';
            if(this.cm.isHidden(col)){
                style += 'display:none;';
            }
            var align = this.cm.config[col].align;
            if(align){
                style += 'text-align:'+align+';';
            }
            return style;
        },

        // private
        getColumnWidth : function(col){
            var w = this.cm.getColumnWidth(col);
            if(Ext.isNumber(w)){
                return (Ext.isBorderBox ? w : (w-this.borderWidth > 0 ? w-this.borderWidth:0)) + 'px';
            }
            return w;
        },

        // private
        getTotalWidth : function(){
            return this.cm.getTotalWidth()+'px';
        },

        // private
        fitColumns : function(preventRefresh, onlyExpand, omitColumn){
            var cm = this.cm, i;
            var tw = cm.getTotalWidth(false);
            var aw = this.grid.getGridEl().getWidth(true)-this.scrollOffset;

            if(aw < 20){ // not initialized, so don't screw up the default widths
                return;
            }
            var extra = aw - tw;

            if(extra === 0){
                return false;
            }

            var vc = cm.getColumnCount(true);
            var ac = vc-(Ext.isNumber(omitColumn) ? 1 : 0);
            if(ac === 0){
                ac = 1;
                omitColumn = undefined;
            }
            var colCount = cm.getColumnCount();
            var cols = [];
            var extraCol = 0;
            var width = 0;
            var w;
            for (i = 0; i < colCount; i++){
                if(!cm.isHidden(i) && !cm.isFixed(i) && i !== omitColumn){
                    w = cm.getColumnWidth(i);
                    cols.push(i);
                    extraCol = i;
                    cols.push(w);
                    width += w;
                }
            }
            var frac = (aw - cm.getTotalWidth())/width;
            while (cols.length){
                w = cols.pop();
                i = cols.pop();
                cm.setColumnWidth(i, Math.max(this.grid.minColumnWidth, Math.floor(w + w*frac)), true);
            }

            if((tw = cm.getTotalWidth(false)) > aw){
                var adjustCol = ac != vc ? omitColumn : extraCol;
                 cm.setColumnWidth(adjustCol, Math.max(1,
                         cm.getColumnWidth(adjustCol)- (tw-aw)), true);
            }

            if(preventRefresh !== true){
                this.updateAllColumnWidths();
            }

            return true;
        },

        // private
        autoExpand : function(preventUpdate){
            var g = this.grid, cm = this.cm;
            if(!this.userResized && g.autoExpandColumn){
                var tw = cm.getTotalWidth(false);
                var aw = this.grid.getGridEl().getWidth(true)-this.scrollOffset;
                if(tw != aw){
                    var ci = cm.getIndexById(g.autoExpandColumn);
                    var currentWidth = cm.getColumnWidth(ci);
                    var cw = Math.min(Math.max(((aw-tw)+currentWidth), g.autoExpandMin), g.autoExpandMax);
                    if(cw != currentWidth){
                        cm.setColumnWidth(ci, cw, true);
                        if(preventUpdate !== true){
                            this.updateColumnWidth(ci, cw);
                        }
                    }
                }
            }
        },

        // private
        getColumnData : function(){
            // build a map for all the columns
            var cs = [], cm = this.cm, colCount = cm.getColumnCount();
            for(var i = 0; i < colCount; i++){
                var name = cm.getDataIndex(i);
                cs[i] = {
                    name : (!Ext.isDefined(name) ? this.ds.fields.get(i).name : name),
                    renderer : cm.getRenderer(i),
                    id : cm.getColumnId(i),
                    style : this.getColumnStyle(i)
                };
            }
            return cs;
        },

        // private
        renderRows : function(startRow, endRow){
            // pull in all the crap needed to render rows
            var g = this.grid, cm = g.colModel, ds = g.store, stripe = g.stripeRows;
            var colCount = cm.getColumnCount();

            if(ds.getCount() < 1){
                return "";
            }

            var cs = this.getColumnData();

            startRow = startRow || 0;
            endRow = !Ext.isDefined(endRow) ? ds.getCount()-1 : endRow;

            // records to render
            var rs = ds.getRange(startRow, endRow);

            return this.doRender(cs, rs, ds, startRow, colCount, stripe);
        },

        // private
        renderBody : function(){
            var markup = this.renderRows() || ' ';
            return this.templates.body.apply({rows: markup});
        },

        // private
        refreshRow : function(record){
            var ds = this.ds, index;
            if(Ext.isNumber(record)){
                index = record;
                record = ds.getAt(index);
                if(!record){
                    return;
                }
            }else{
                index = ds.indexOf(record);
                if(index < 0){
                    return;
                }
            }
            this.insertRows(ds, index, index, true);
            this.getRow(index).rowIndex = index;
            this.onRemove(ds, record, index+1, true);
            this.fireEvent("rowupdated", this, index, record);
        },

        /**
         * Refreshs the grid UI
         * @param {Boolean} headersToo (optional) True to also refresh the headers
         */
        refresh : function(headersToo){
            this.fireEvent("beforerefresh", this);
            this.grid.stopEditing(true);

            var result = this.renderBody();
            this.mainBody.update(result).setWidth(this.getTotalWidth());
            if(headersToo === true){
                this.updateHeaders();
                this.updateHeaderSortState();
            }
            this.processRows(0, true);
            this.layout();
            this.applyEmptyText();
            this.fireEvent("refresh", this);
        },

        // private
        applyEmptyText : function(){
            if(this.emptyText && !this.hasRows()){
                this.mainBody.update('' + this.emptyText + '');
            }
        },

        // private
        updateHeaderSortState : function(){
            var state = this.ds.getSortState();
            if(!state){
                return;
            }
            if(!this.sortState || (this.sortState.field != state.field || this.sortState.direction != state.direction)){
                this.grid.fireEvent('sortchange', this.grid, state);
            }
            this.sortState = state;
            var sortColumn = this.cm.findColumnIndex(state.field);
            if(sortColumn != -1){
                var sortDir = state.direction;
                this.updateSortIcon(sortColumn, sortDir);
            }
        },

        // private
        destroy : function(){
            if(this.colMenu){
                Ext.menu.MenuMgr.unregister(this.colMenu);
                this.colMenu.destroy();
                delete this.colMenu;
            }
            if(this.hmenu){
                Ext.menu.MenuMgr.unregister(this.hmenu);
                this.hmenu.destroy();
                delete this.hmenu;
            }
            if(this.grid.enableColumnMove){
                var dds = Ext.dd.DDM.ids['gridHeader' + this.grid.getGridEl().id];
                if(dds){
                    for(var dd in dds){
                        if(!dds[dd].config.isTarget && dds[dd].dragElId){
                            var elid = dds[dd].dragElId;
                            dds[dd].unreg();
                            Ext.get(elid).remove();
                        } else if(dds[dd].config.isTarget){
                            dds[dd].proxyTop.remove();
                            dds[dd].proxyBottom.remove();
                            dds[dd].unreg();
                        }
                        if(Ext.dd.DDM.locationCache[dd]){
                            delete Ext.dd.DDM.locationCache[dd];
                        }
                    }
                    delete Ext.dd.DDM.ids['gridHeader' + this.grid.getGridEl().id];
                }
            }

            if(this.dragZone){
                this.dragZone.unreg();
            }

            Ext.fly(this.innerHd).removeAllListeners();
            Ext.removeNode(this.innerHd);

            Ext.destroy(this.resizeMarker, this.resizeProxy, this.focusEl, this.mainBody,
                        this.scroller, this.mainHd, this.mainWrap, this.dragZone,
                        this.splitZone, this.columnDrag, this.columnDrop);

            this.initData(null, null);
            Ext.EventManager.removeResizeListener(this.onWindowResize, this);
            this.purgeListeners();
        },

        // private
        onDenyColumnHide : function(){

        },

        // private
        render : function(){
            if(this.autoFill){
                var ct = this.grid.ownerCt;
                if (ct && ct.getLayout()){
                    ct.on('afterlayout', function(){
                        this.fitColumns(true, true);
                        this.updateHeaders();
                    }, this, {single: true});
                }else{
                    this.fitColumns(true, true);
                }
            }else if(this.forceFit){
                this.fitColumns(true, false);
            }else if(this.grid.autoExpandColumn){
                this.autoExpand(true);
            }

            this.renderUI();
        },

        /* --------------------------------- Model Events and Handlers --------------------------------*/
        // private
        initData : function(ds, cm){
            if(this.ds){
                this.ds.un("load", this.onLoad, this);
                this.ds.un("datachanged", this.onDataChange, this);
                this.ds.un("add", this.onAdd, this);
                this.ds.un("remove", this.onRemove, this);
                this.ds.un("update", this.onUpdate, this);
                this.ds.un("clear", this.onClear, this);
                if(this.ds !== ds && this.ds.autoDestroy){
                    this.ds.destroy();
                }
            }
            if(ds){
                ds.on({
                    scope: this,
                    load: this.onLoad,
                    datachanged: this.onDataChange,
                    add: this.onAdd,
                    remove: this.onRemove,
                    update: this.onUpdate,
                    clear: this.onClear
                });
            }
            this.ds = ds;

            if(this.cm){
                this.cm.un("configchange", this.onColConfigChange, this);
                this.cm.un("widthchange", this.onColWidthChange, this);
                this.cm.un("headerchange", this.onHeaderChange, this);
                this.cm.un("hiddenchange", this.onHiddenChange, this);
                this.cm.un("columnmoved", this.onColumnMove, this);
            }
            if(cm){
                delete this.lastViewWidth;
                cm.on({
                    scope: this,
                    configchange: this.onColConfigChange,
                    widthchange: this.onColWidthChange,
                    headerchange: this.onHeaderChange,
                    hiddenchange: this.onHiddenChange,
                    columnmoved: this.onColumnMove
                });
            }
            this.cm = cm;
        },

        // private
        onDataChange : function(){
            this.refresh();
            this.updateHeaderSortState();
            this.syncFocusEl(0);
        },

        // private
        onClear : function(){
            this.refresh();
            this.syncFocusEl(0);
        },

        // private
        onUpdate : function(ds, record){
            this.refreshRow(record);
        },

        // private
        onAdd : function(ds, records, index){
            this.insertRows(ds, index, index + (records.length-1));
        },

        // private
        onRemove : function(ds, record, index, isUpdate){
            if(isUpdate !== true){
                this.fireEvent("beforerowremoved", this, index, record);
            }
            this.removeRow(index);
            if(isUpdate !== true){
                this.processRows(index);
                this.applyEmptyText();
                this.fireEvent("rowremoved", this, index, record);
            }
        },

        // private
        onLoad : function(){
            this.scrollToTop();
        },

        // private
        onColWidthChange : function(cm, col, width){
            this.updateColumnWidth(col, width);
        },

        // private
        onHeaderChange : function(cm, col, text){
            this.updateHeaders();
        },

        // private
        onHiddenChange : function(cm, col, hidden){
            this.updateColumnHidden(col, hidden);
        },

        // private
        onColumnMove : function(cm, oldIndex, newIndex){
            this.indexMap = null;
            var s = this.getScrollState();
            this.refresh(true);
            this.restoreScroll(s);
            this.afterMove(newIndex);
            this.grid.fireEvent('columnmove', oldIndex, newIndex);
        },

        // private
        onColConfigChange : function(){
            delete this.lastViewWidth;
            this.indexMap = null;
            this.refresh(true);
        },

        /* -------------------- UI Events and Handlers ------------------------------ */
        // private
        initUI : function(grid){
            grid.on("headerclick", this.onHeaderClick, this);
        },

        // private
        initEvents : function(){
        },

        // private
        onHeaderClick : function(g, index){
            if(this.headersDisabled || !this.cm.isSortable(index)){
                return;
            }
            g.stopEditing(true);
            g.store.sort(this.cm.getDataIndex(index));
        },

        // private
        onRowOver : function(e, t){
            var row;
            if((row = this.findRowIndex(t)) !== false){
                this.addRowClass(row, "x-grid3-row-over");
            }
        },

        // private
        onRowOut : function(e, t){
            var row;
            if((row = this.findRowIndex(t)) !== false && !e.within(this.getRow(row), true)){
                this.removeRowClass(row, "x-grid3-row-over");
            }
        },

        // private
        handleWheel : function(e){
            e.stopPropagation();
        },

        // private
        onRowSelect : function(row){
            this.addRowClass(row, this.selectedRowClass);
        },

        // private
        onRowDeselect : function(row){
            this.removeRowClass(row, this.selectedRowClass);
        },

        // private
        onCellSelect : function(row, col){
            var cell = this.getCell(row, col);
            if(cell){
                this.fly(cell).addClass("x-grid3-cell-selected");
            }
        },

        // private
        onCellDeselect : function(row, col){
            var cell = this.getCell(row, col);
            if(cell){
                this.fly(cell).removeClass("x-grid3-cell-selected");
            }
        },

        // private
        onColumnSplitterMoved : function(i, w){
            this.userResized = true;
            var cm = this.grid.colModel;
            cm.setColumnWidth(i, w, true);

            if(this.forceFit){
                this.fitColumns(true, false, i);
                this.updateAllColumnWidths();
            }else{
                this.updateColumnWidth(i, w);
                this.syncHeaderScroll();
            }

            this.grid.fireEvent("columnresize", i, w);
        },

        // private
        handleHdMenuClick : function(item){
            var index = this.hdCtxIndex;
            var cm = this.cm, ds = this.ds;
            switch(item.itemId){
                case "asc":
                    ds.sort(cm.getDataIndex(index), "ASC");
                    break;
                case "desc":
                    ds.sort(cm.getDataIndex(index), "DESC");
                    break;
                default:
                    index = cm.getIndexById(item.itemId.substr(4));
                    if(index != -1){
                        if(item.checked && cm.getColumnsBy(this.isHideableColumn, this).length <= 1){
                            this.onDenyColumnHide();
                            return false;
                        }
                        cm.setHidden(index, item.checked);
                    }
            }
            return true;
        },

        // private
        isHideableColumn : function(c){
            return !c.hidden && !c.fixed;
        },

        // private
        beforeColMenuShow : function(){
            var cm = this.cm,  colCount = cm.getColumnCount();
            this.colMenu.removeAll();
            for(var i = 0; i < colCount; i++){
                if(cm.config[i].fixed !== true && cm.config[i].hideable !== false){
                    this.colMenu.add(new Ext.menu.CheckItem({
                        itemId: "col-"+cm.getColumnId(i),
                        text: cm.getColumnHeader(i),
                        checked: !cm.isHidden(i),
                        hideOnClick:false,
                        disabled: cm.config[i].hideable === false
                    }));
                }
            }
        },

        // private
        handleHdDown : function(e, t){
            if(Ext.fly(t).hasClass('x-grid3-hd-btn')){
                e.stopEvent();
                var hd = this.findHeaderCell(t);
                Ext.fly(hd).addClass('x-grid3-hd-menu-open');
                var index = this.getCellIndex(hd);
                this.hdCtxIndex = index;
                var ms = this.hmenu.items, cm = this.cm;
                ms.get("asc").setDisabled(!cm.isSortable(index));
                ms.get("desc").setDisabled(!cm.isSortable(index));
                this.hmenu.on("hide", function(){
                    Ext.fly(hd).removeClass('x-grid3-hd-menu-open');
                }, this, {single:true});
                this.hmenu.show(t, "tl-bl?");
            }
        },

        // private
        handleHdOver : function(e, t){
            var hd = this.findHeaderCell(t);
            if(hd && !this.headersDisabled){
                this.activeHd = hd;
                this.activeHdIndex = this.getCellIndex(hd);
                var fly = this.fly(hd);
                this.activeHdRegion = fly.getRegion();
                if(!this.cm.isMenuDisabled(this.activeHdIndex)){
                    fly.addClass("x-grid3-hd-over");
                    this.activeHdBtn = fly.child('.x-grid3-hd-btn');
                    if(this.activeHdBtn){
                        this.activeHdBtn.dom.style.height = (hd.firstChild.offsetHeight-1)+'px';
                    }
                }
            }
        },

        // private
        handleHdMove : function(e, t){
            if(this.activeHd && !this.headersDisabled){
                var hw = this.splitHandleWidth || 5;
                var r = this.activeHdRegion;
                var x = e.getPageX();
                var ss = this.activeHd.style;
                if(x - r.left <= hw && this.cm.isResizable(this.activeHdIndex-1)){
                    ss.cursor = Ext.isAir ? 'move' : Ext.isWebKit ? 'e-resize' : 'col-resize'; // col-resize not always supported
                }else if(r.right - x <= (!this.activeHdBtn ? hw : 2) && this.cm.isResizable(this.activeHdIndex)){
                    ss.cursor = Ext.isAir ? 'move' : Ext.isWebKit ? 'w-resize' : 'col-resize';
                }else{
                    ss.cursor = '';
                }
            }
        },

        // private
        handleHdOut : function(e, t){
            var hd = this.findHeaderCell(t);
            if(hd && (!Ext.isIE || !e.within(hd, true))){
                this.activeHd = null;
                this.fly(hd).removeClass("x-grid3-hd-over");
                hd.style.cursor = '';
            }
        },

        // private
        hasRows : function(){
            var fc = this.mainBody.dom.firstChild;
            return fc && fc.nodeType == 1 && fc.className != 'x-grid-empty';
        },

        // back compat
        bind : function(d, c){
            this.initData(d, c);
        }
    });

    // private
    // This is a support class used internally by the Grid components
    Ext.grid.GridView.SplitDragZone = function(grid, hd){
        this.grid = grid;
        this.view = grid.getView();
        this.marker = this.view.resizeMarker;
        this.proxy = this.view.resizeProxy;
        Ext.grid.GridView.SplitDragZone.superclass.constructor.call(this, hd,
            "gridSplitters" + this.grid.getGridEl().id, {
            dragElId : Ext.id(this.proxy.dom), resizeFrame:false
        });
        this.scroll = false;
        this.hw = this.view.splitHandleWidth || 5;
    };
    Ext.extend(Ext.grid.GridView.SplitDragZone, Ext.dd.DDProxy, {

        b4StartDrag : function(x, y){
            this.view.headersDisabled = true;
            var h = this.view.mainWrap.getHeight();
            this.marker.setHeight(h);
            this.marker.show();
            this.marker.alignTo(this.view.getHeaderCell(this.cellIndex), 'tl-tl', [-2, 0]);
            this.proxy.setHeight(h);
            var w = this.cm.getColumnWidth(this.cellIndex);
            var minw = Math.max(w-this.grid.minColumnWidth, 0);
            this.resetConstraints();
            this.setXConstraint(minw, 1000);
            this.setYConstraint(0, 0);
            this.minX = x - minw;
            this.maxX = x + 1000;
            this.startPos = x;
            Ext.dd.DDProxy.prototype.b4StartDrag.call(this, x, y);
        },

        handleMouseDown : function(e){
            var t = this.view.findHeaderCell(e.getTarget());
            if(t){
                var xy = this.view.fly(t).getXY(), x = xy[0], y = xy[1];
                var exy = e.getXY(), ex = exy[0];
                var w = t.offsetWidth, adjust = false;
                if((ex - x) <= this.hw){
                    adjust = -1;
                }else if((x+w) - ex <= this.hw){
                    adjust = 0;
                }
                if(adjust !== false){
                    this.cm = this.grid.colModel;
                    var ci = this.view.getCellIndex(t);
                    if(adjust == -1){
                      if (ci + adjust < 0) {
                        return;
                      }
                        while(this.cm.isHidden(ci+adjust)){
                            --adjust;
                            if(ci+adjust < 0){
                                return;
                            }
                        }
                    }
                    this.cellIndex = ci+adjust;
                    this.split = t.dom;
                    if(this.cm.isResizable(this.cellIndex) && !this.cm.isFixed(this.cellIndex)){
                        Ext.grid.GridView.SplitDragZone.superclass.handleMouseDown.apply(this, arguments);
                    }
                }else if(this.view.columnDrag){
                    this.view.columnDrag.callHandleMouseDown(e);
                }
            }
        },

        endDrag : function(e){
            this.marker.hide();
            var v = this.view;
            var endX = Math.max(this.minX, e.getPageX());
            var diff = endX - this.startPos;
            v.onColumnSplitterMoved(this.cellIndex, this.cm.getColumnWidth(this.cellIndex)+diff);
            setTimeout(function(){
                v.headersDisabled = false;
            }, 50);
        },

        autoOffset : function(){
            this.setDelta(0,0);
        }
    });