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
} );
		
		ExpressionProvider ep = new ChartExpressionProvider( designHandle,
				context,
				ChartReportItemUIUtil.getExpressionBuilderStyle( IUIServiceProvider.COMMAND_EXPRESSION_DATA_BINDINGS ) );
		expButton = ChartExpressionButtonUtil.createExpressionButton( condition,
				expression,
				(ExtendedItemHandle) designHandle,
				ep );
		expButton.addListener( new Listener( ) {
			public void handleEvent( Event event )
			{
				if ( event.data instanceof String[] )
				{
					updateButtons( );
					if ( !expButton.getExpression( ).equals( fCurrentExpr ) )
					{
						needRefreshList = true;
						fCurrentExpr = expButton.getExpression( );
					}
				}
			}
		} );
		expButton.setPredefinedQuery( getDataSetColumns( ) );
            
		operator = new Combo( condition, SWT.READ_ONLY );
		for ( int i = 0; i < OPERATOR.length; i++ )
		{
			operator.add( OPERATOR[i][0] );
		}