legend item visibility inconsistency

[M]

Hi, ​how to make  legend items collapsed when the series visibility is set to collapsed / hidden (previously they were only collapsed when the series was collapsed and visible when the series was hidden).

   <ScrollViewer  VerticalScrollBarVisibility="Hidden" BorderBrush="Transparent"  Grid.Column="1" >
            <telerik:RadLegend  Visibility="Visible"   BorderBrush="Transparent" Margin="0,15,0,0"
                          Items="{Binding LegendItems, ElementName=chart ,Mode=TwoWay}"
                          Foreground="#FF767676"
                           FontFamily="Segoe UI" 
                            HorizontalAlignment="Left" 
                            FlowDirection="RightToLeft" 
                            VerticalAlignment="Bottom" 
                            VerticalContentAlignment="Stretch"
                            HorizontalContentAlignment="Stretch" 
                                   UseLayoutRounding="True"
                            VirtualizingStackPanel.VirtualizationMode="Recycling"
                            HoverMode="HighlightItem"
                            />
            
        </ScrollViewer>

[Petar Marchev]

Hello,

The legend item should not be visible when the series is collapsed. I created a small project and I can confirm that there is a bug in the control. I have logged it in our feedback portal where you can vote and track its status and updated your Telerik points as a thank you for letting us know if this issue.

You can use a simple work-around for this. Use a template that has bound Visibility to the Visibility of the series:

<DataTemplate x:Key="legendItemTemplate1">
 <StackPanel Orientation="Horizontal" Visibility="{Binding Presenter.Visibility}">
 <Path Fill="{Binding MarkerFill}" Width="12" Height="12">
   <Path.Data>
    <Binding Path="ActualMarkerGeometry" RelativeSource="{RelativeSource AncestorType=telerik:LegendItemControl}">
     <Binding.Converter>
      <telerik:GeometryCloneConverter />
     </Binding.Converter>
    </Binding>
   </Path.Data>
   </Path>
  <TextBlock Margin="2" Text="{Binding Title}" />
 </StackPanel>
</DataTemplate>

I am just a little confused about the part where you mention that the legend item was collapsed when the series is hidden. There is no Hidden Visibility in Silverlight and I am unsure if I answered all of your questions. If you need more information, do contact us again and we will try to assist.

Regards,
Petar Marchev
Telerik

[Petar Marchev]

Hello Jalil,

After a short investigation it seems that the behavior that you described is expected. I was incorrect to state that this is a bug, when this is actually the desired effect.

This is how we want the control to behave because we want to support a certain scenario. You can see this online QSF example where the interaction relies on legend items being produced for collapsed . series. You can see the RadLegend in the bottom right corner. The items have been retemplated and a toggle button has been used. The toggle button controls the visibility of the series. However, if the legend item disappeared when you clicked on it (and collapsed a series) there would be no way to bring the series back.

This is why I have declined the bug report I logged earlier today. I apologize for misleading you with my previous post.

You can still use the previously suggested work-around where the Visibility of the LegendItem is synced with the Visibility of the series. This way the chart will still produce a legend item, but the presenter will be collapsed. If you wish for the chart not to create a legend item, you can simply set the LegendSettings property to false (you can use a binding and a converter for this purpose).

One last thing, in the project I sent if you were to remove the item template, the chart will produce a legend item without a properly set MarkerBrush. We will investigate to see if we can improve things in this direction, so that the legend can display properly.

Regards,
Petar Marchev
Telerik