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
}
		}
		else
		{
			for ( int i = 0; i < fHeadings.size( ); i++ )
			{
				addHeaderButton( iHeaderAlignment,
						fHeadings.elementAt( i ),
						columnWidths.get( i ),
						i );
			}
		}
		cmpHeaders.layout( );
		
		if ( cnvCells != null && !cnvCells.isDisposed( ) )
		{
			cnvCells.dispose( );
		}
		cnvCells = new TableCanvas( this,
				SWT.NONE,
				fHeadings.size( ),
				new Color[]{},
				this );
		cnvCells.setLayoutData( new GridData( GridData.FILL_BOTH ) );
		cnvCells.setBackground( Display.getCurrent( )
				.getSystemColor( SWT.COLOR_LIST_BACKGROUND ) );
		cnvCells.addMouseMoveListener( this );
		getShell( ).addControlListener( this );
		addDisposeListener( this );
	}