 [IconFile("ColumnHeaderBar.png")]
 
 /**
- *  The ColumnHeaderBar control defines
- * 
- *  @langversion 3.0
- *  @playerversion Flash 10
- *  @playerversion AIR 2.0
- *  @productversion Flex 4.5
- */
-public class ColumnHeaderBar extends Group implements IFocusManagerComponent 
+ *  Displays a row of column headers and separators aligned with the grid's layout.  
+ * 
+ *  <p>Headers are rendererd with the headerRenderer and separators with the columnSeparator.
+ *  The layout, which can not be changed, is virtual: renderers and separators that have been 
+ *  scrolled out of view are reused.</p>
+ * 
+ *  @langversion 3.0
+ *  @playerversion Flash 10
+ *  @playerversion AIR 2.0
+ *  @productversion Flex 4.5
+ */
+public class ColumnHeaderBar extends Group implements IDataGridElement, IFocusManagerComponent 
 {
     include "../core/Version.as";
     

import mx.core.IFactory;
import mx.core.IVisualElement;
import mx.core.mx_internal;
import mx.managers.CursorManager;
import mx.managers.CursorManagerPriority;
import mx.managers.IFocusManagerComponent;

import spark.components.supportClasses.ColumnHeaderBarLayout;
import spark.components.supportClasses.GridColumn;
import spark.components.supportClasses.GridLayer;

    //
    //--------------------------------------------------------------------------
    
    private function getColumnAt(columnIndex:int):GridColumn
    {
        const grid:Grid = (dataGrid) ? dataGrid.grid : null;
        if (!grid || !grid.columns)
            return null;
        
