Bug 210716 Support switch Text/Chart view in crosstab cell
Need crosstab UI provide support to switch between Text and Chart view in measure/aggregation cell.
xtab/org.eclipse.birt.report.item.crosstab.core/src/org/eclipse/birt/report/item/crosstab/core/de/internal/CrosstabModelUtil.java
*/
	public static void addDataItem( CrosstabReportItemHandle crosstab,
			MeasureViewHandle measureView, String function,
			String rowDimension, String rowLevel, String colDimension,
			String colLevel ) throws SemanticException
	{
		if ( crosstab == null || measureView == null )
			return;
		
		AggregationCellHandle cell = measureView.getAggregationCell( rowDimension,
				rowLevel,
				colDimension,
				colLevel );
		if ( cell == null )
		{
			cell = measureView.addAggregation( rowDimension,
					rowLevel,
					colDimension,
					colLevel );
		}
		if ( cell != null && cell.getContents( ).size( ) == 0 )
		{
			
			String name = CrosstabModelUtil.generateComputedColumnName( measureView,
					colLevel,
					rowLevel );
			ComputedColumn column = StructureFactory.newComputedColumn( crosstab.getModelHandle( ),
					name );
			String dataType = measureView.getDataType( );
			column.setDataType( dataType );