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
fireMenuEvent( btnHeader, false );
		
		addHeaderSplitter( );
	}
	private void addHeaderSplitter( )
	{
		Label splitter = new Label( cmpHeaders, SWT.NONE );
		FormData fd = new FormData( );
		fd.top = new FormAttachment( 2 );
		int i = btnHeaders.size( );
		if ( i == 0 )
		{
			fd.left = new FormAttachment( 0 );
		}
		else
		{
			Button btnNeighbor = btnHeaders.get( i - 1 );
			fd.left = new FormAttachment( btnNeighbor );
		}
		fd.width = SPLITTER_WIDTH;
		splitter.setLayoutData( fd );
		splitter.setData( Integer.valueOf( i - 1 ) );
		splitter.addMouseListener( this );
		splitter.addMouseMoveListener( this );
	}