title: Trying to force WPF Ribbon to always show ribbon tab groups as collapsed (until the user opens them up)
body: <p>I am trying to force WPF Ribbon to always show ribbon tab groups as collapsed (until the user opens them up).
  I defined a resource defining ribbon group size definitions with the group size definition of collapesed group. Then I am using that static resource to set GroupSizeDefinitions property of the style for a RibbonGroup. However, I do see some of the groups not in collapsed state. Do I miss something in my xaml?:</p>
  
  <pre><code>&lt;ribbon:RibbonGroupSizeDefinitionBaseCollection x:Key="groupSizeDefinitions"&gt;
      &lt;ribbon:RibbonGroupSizeDefinition IsCollapsed="True"/&gt;
  &lt;/ribbon:RibbonGroupSizeDefinitionBaseCollection&gt;
  &lt;ItemsPanelTemplate x:Key="groupItemsPanelTemplate"&gt;
      &lt;StackPanel Orientation="Horizontal"/&gt;
  &lt;/ItemsPanelTemplate&gt;
  &lt;Style TargetType="{x:Type ribbon:RibbonGroup}" BasedOn="{StaticResource RibbonControlStyle}"&gt;
      &lt;Setter Property="QuickAccessToolBarId" Value="{Binding Label}" /&gt;
      &lt;Setter Property="Header" Value="{Binding Label}" /&gt;
      &lt;Setter Property="ItemsSource" Value="{Binding ControlDataCollection}" /&gt;
      &lt;Setter Property="ribbon:RibbonTwoLineText.Foreground" Value="Black" /&gt;
      &lt;Setter Property="ItemsPanel" Value="{StaticResource groupItemsPanelTemplate}"/&gt;
      &lt;Setter Property="GroupSizeDefinitions"  Value="{StaticResource groupSizeDefinitions}"/&gt;
  &lt;/Style&gt;
  </code></pre>