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
if ( offset > this.getVisibleTableWidth( ) )
			{
			offset -= this.getVisibleTableWidth( );
			iHiddenWidth = offset;
			
			if ( btnHeaders.size( ) > 0 )
			{
				
				
				Button btn = btnHeaders.get( 0 );
				( (FormData) btn.getLayoutData( ) ).left = new FormAttachment( 0,
						-offset );
			}
			}
			
			getHorizontalBar( ).setSelection( offset );
			cmpHeaders.layout( );
			
			selectColumn( index );
			iLastProcessedHorizontalScrollPosition = getHorizontalBar( ).getSelection( );
			redraw( );
		}
		
		public void widgetSelected( SelectionEvent e )
		{
			if ( e.getSource( ) instanceof ScrollBar )
			{
				ScrollBar sb = (ScrollBar) e.getSource( );
				if ( ( sb.getStyle( ) | SWT.H_SCROLL ) == SWT.H_SCROLL )
				{