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
int max = 0;
			for ( int i = 0; i < columnWidths.size( ); i++ )
			{
				max += columnWidths.get( i ).intValue( );
			}
			return max;
		}
		private int getVisibleTableWidth( )
		{
			int iVisibleTableWidth = getTableSize( ).x;
			if ( iVisibleTableWidth == 0 )
			{
				iVisibleTableWidth = getParent( ).computeSize( SWT.DEFAULT,
						SWT.DEFAULT ).x;
			}
			
			return iVisibleTableWidth - 20;
		}
		/**
		 * Calculates the max width of specified column data.
		 * 
		 * @param columnIndex
		 * @param control
		 */
		private int calculateMaxColumnWidth( int columnIndex, Control control )
		{
			int maxWidth = 10;
			GC gc = new GC( control );
			Vector columnTexts = cells[columnIndex];
			for ( int rowIndex = 0; rowIndex < columnTexts.size( ); rowIndex++ )