cmpTask = null;
	public void widgetDisposed( DisposeEvent e )	{		super.widgetDisposed( e );		htVisibleSheets.clear( );		htVisibleDisplayName.clear( );		htSheetCollections.clear( );		cmpTask = null;		previewCanvas = null;		if ( previewPainter != null )		{			previewPainter.dispose( );		}		previewPainter = null;	}