Bug 312859 The list of operator for Chart filter does not provide 30 visible items
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/dialogs/ChartCubeFilterConditionBuilder.java
String expr = adaptExpr( exprCodec );
			exprMap.put( exprCodec.getBindingName( ), expr ); 
		}
		
		return exprMap;
	}
	
	protected String[] getDataSetColumns( )
	{
		if ( columnList.isEmpty( ) )
		{
			return EMPTY;
		}
		String[] values = new String[columnList.size( )];
		for ( int i = 0; i < columnList.size( ); i++ )
		{
			values[i] = columnList.get( i );
		}
		return values;
	}
	
	protected Object getResultSetColumn( String name )
	{
		if ( columnList.isEmpty( ) )
		{
			return null;
		}
		for ( int i = 0; i < columnList.size( ); i++ )
		{
			if ( columnList.get( i ).equals( name ) )