How to bind to property of sibling control?

Question

In a listbox of items, one item can be designated as the primary item. In the template, I have a button bound to a parameterized command (the specific item in the collection is the parameter passed to the command in the datacontext) that is visible only if the item is not currently the primary item. If the item IS the primary item, I want to display a static image. Since I can't bind the image to the command to witch I am binding the button, I figured I could bind the Visibility property of the image to the "inverse" of the Visibility property of the button. (i.e. when the button is visible, the image is hidden and vice versa.) But I can't figure out how to do this. The button is a sibling of the image within a grid within the template. Here's my template...

<DataTemplate>
  <StackPanel Orientation="Vertical">
    <Grid>
      <Grid.ColumnDefinitions>
      ...
      </Grid.ColumnDefinitions>

      <TextBlock Grid.Column="0" Text="{Binding Path=FormattedNumber}" Style="{StaticResource FieldDataTextBlock}" FontWeight="Bold" />
      <!-- How can I make this image aware of the following button's state? -->
      <Image Grid.Column="2" Source="/Resources/Star.Pressed.png" Visibility="{Binding RelativeSource={RelativeSource AncestorType=Grid}, Path={}}" Width="20" Height="20" />
      <Button Grid.Column="2" x:Name="btnMakePrimary" Style="{StaticResource StarButton}" Command="{Binding ElementName=lstPhoneNumbers, Path=DataContext.MakePrimaryPhoneNumberCommand}" CommandParameter="{Binding}" ToolTip="Set as display number." Visibility="{Binding Path=IsEnabled, RelativeSource={RelativeSource Self}, Converter={StaticResource BoolVisibility}}" />
      <Button Grid.Column="4" Style="{StaticResource DetailsButton}" Command="{Binding ElementName=lstPhoneNumbers, Path=DataContext.ViewPhoneNumberCommand}" CommandParameter="{Binding}" />
      <Button Grid.Column="6" Style="{StaticResource DeleteButton}" Command="{Binding ElementName=lstPhoneNumbers, Path=DataContext.DeletePhoneNumberCommand}" CommandParameter="{Binding}" />
    </Grid>
    <Grid >
      <Grid.ColumnDefinitions>
      ...
      </Grid.ColumnDefinitions>

      <TextBlock Grid.Column="0" Text="{Binding Path=PhoneTypeString}" Style="{StaticResource FieldDataTextBlock}" />
      <TextBlock Grid.Column="2" Text="(notes)" Foreground="Blue" ToolTip="{Binding Path=PhoneNumberNote}" Visibility="{Binding Path=HasNote, Converter={StaticResource BoolVisibility}}" />
    </Grid>
  </StackPanel>
</DataTemplate>

Either that, or is there a way to bind the image to a method in the parent datacontext that takes a parameter?

Thanks.

J

Answer 1

Never mind... I was able to make it happen via the ElementName attribute of the binding and fixing an issue with the included image resource which was messing with my visuals:

<Button Grid.Column="2" Name="btnMakePrimary" Style="{StaticResource StarButton}" Command="{Binding ElementName=lstPhoneNumbers, Path=DataContext.MakePrimaryPhoneNumberCommand}" CommandParameter="{Binding}" ToolTip="Set as display number." Visibility="{Binding Path=IsEnabled, RelativeSource={RelativeSource Self}, Converter={StaticResource BoolVisibility}}" />
<Image Grid.Column="2" Source="/Resources/Star.Pressed.png" Visibility="{Binding ElementName=btnMakePrimary, Path=IsEnabled, Converter={StaticResource BoolVisibilityReverse}}" Width="20" Height="20" />