Bug 390669 [Accessibility]Press 'Tab' doesn't focus on the next report item when adding relative period aggregation.
xtab/org.eclipse.birt.report.item.crosstab.ui/src/org/eclipse/birt/report/item/crosstab/internal/ui/dialogs/CrosstabBindingDialogHelper.java
.getDisplayName( );
		}
		catch ( BirtException e )
		{
			ExceptionUtil.handle( e );
			return null;
		}
	}
	private IAggrFunction[] getFunctions( )
	{
		try
		{
			List aggrInfoList = DataUtil.getAggregationManager( )
					.getAggregations( AggregationManager.AGGR_XTAB );
			return (IAggrFunction[]) aggrInfoList.toArray( new IAggrFunction[0] );
		}
		catch ( BirtException e )
		{
			ExceptionUtil.handle( e );
			return new IAggrFunction[0];
		}
	}
	private String getDataTypeDisplayName( String dataType )
	{
		for ( int i = 0; i < DATA_TYPE_CHOICES.length; i++ )
		{
			if ( dataType.equals( DATA_TYPE_CHOICES[i].getName( ) ) )
			{
				return DATA_TYPE_CHOICES[i].getDisplayName( );
			}