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
value = value.trim( );
			}
			if ( valueList.indexOf( value ) < 0 )
			{
				addBtn.setEnabled( true );
			}
			else
			{
				addBtn.setEnabled( false );
			}
		}
	}
	protected void checkEditDelButtonStatus( )
	{
		if ( tableViewer == null )
		{
			return;
		}
		boolean enabled = ( tableViewer.getSelection( ) == null ) ? false
				: true;
		if ( enabled == true
				&& tableViewer.getSelection( ) instanceof StructuredSelection )
		{
			StructuredSelection selection = (StructuredSelection) tableViewer.getSelection( );
			if ( selection.toList( ).size( ) <= 0 )
			{
				enabled = false;
			}
		}
		editBtn.setEnabled( enabled );