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
{
					btnHeaders.elementAt( iColumnIndex ).setFocus( );
				}
				redraw( );
			}
			else
			{
				iColumnIndex = -1;
				for ( int i = 0, iTmp = 0; i < columnWidths.size( ); i++ )
				{
					iTmp = getAdjustedLeftEdgeForColumn( i );
					if ( iTmp > e.x )
					{
						iColumnIndex = i - 1;
						break;
					}
					iColumnIndex = i;
				}
				Button currentButton = btnHeaders.elementAt( iColumnIndex );
				currentButton.setFocus( );
				fireMenuEvent( currentButton, true );
			}
		}
		public void moveTo(int index )
		{
			int offset = 0;
			for ( int i = 0; i <= index; i++ )
			{
				offset += columnWidths.get( i ).intValue( ) ;
			}