Bug 313297 XML data set fail in chart data preview
chart/org.eclipse.birt.chart.ui/src/org/eclipse/birt/chart/ui/swt/CustomPreviewTable.java
* BOOLEAN INDICATING A DRAG OPERATION IS IN PROGRESS...USED TO DETERMINE IF
	 * CELLS ARE TO BE REDRAWN
	 */
	transient boolean bDragging = false;
	
	private transient int iResizingColumnIndex = -1;
	
	private transient int iDragStartXLocation = -1;
	
	private transient int iHiddenWidth = 0;
	Listener headerButtonListener = new Listener( ) {
		public void handleEvent( Event event )
		{
			switch ( event.type )
			{
				case SWT.Selection :
					
					cnvCells.selectColumn( btnHeaders.indexOf( event.widget ) );
					break;
				case SWT.FocusIn :
					
					iColumnIndex = btnHeaders.indexOf( event.widget );
					Event newEvent = new Event( );
					newEvent.widget = event.widget;
					newEvent.type = FOCUS_IN;
					newEvent.data = Integer.valueOf( iColumnIndex );
					fireEvent( newEvent );
					break;
			}
		}