AvalonDock - prevent anchorable pane docking in document pane

Question

Is it possible to prevent an anchorable being docked into my documents pane? I want them to be draggable and moved around the screen, but sometimes users drag them into the documents pane which makes them look poor. Then they close the tab and I can't re-open the anchorable.

If it helps my Avalon code is below:

        <avalonDock:DockingManager.Theme>
            <avalonDock:VS2010Theme />
        </avalonDock:DockingManager.Theme>

        <avalonDock:DockingManager.DocumentHeaderTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <StackPanel Orientation="Horizontal">
                        <!-- the TextBlock named Limiter is used to limit the height of the TextBlock for the workflow name. -->
                        <TextBlock x:Name="Limiter" TextWrapping="NoWrap" Visibility="Hidden"
                                                       TextTrimming="CharacterEllipsis">
                                                L
                        </TextBlock>
                        <TextBlock Text="{Binding Path=Title}" VerticalAlignment="Center"
                                   ToolTip="{StaticResource WorkflowTabItemToolTip}"
                                   MaxHeight="{Binding ActualHeight, ElementName=Limiter}" MaxWidth="150"
                                   TextWrapping="NoWrap" TextTrimming="CharacterEllipsis" Margin="0,0,2,0" 
                                   AutomationProperties.AutomationId="WorkflowTabTitleText"/>
                        <TextBlock Text=" *" 
                                   ToolTip="Has unsaved changes"
                                   Visibility="{Binding Content.UnsavedEdits, Converter={StaticResource BoolToVis}}"
                                   AutomationProperties.AutomationId="DirtyTabIndicator"/>
                    </StackPanel>
                </StackPanel>
            </DataTemplate>
        </avalonDock:DockingManager.DocumentHeaderTemplate>

        <avalonDock:DockingManager.LayoutItemContainerStyleSelector>
            <utilities1:PanesStyleSelector>
                <utilities1:PanesStyleSelector.WebUIStyle>
                    <Style TargetType="{x:Type avalonDock:LayoutAnchorableItem}">
                        <Setter Property="Title" Value="{Binding Model.Title}"/>
                        <Setter Property="IconSource" Value="{Binding Model.IconSource}"/>
                        <Setter Property="Visibility" Value="{Binding Model.IsVisible, Mode=TwoWay, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter={x:Static Visibility.Hidden}}"/>
                        <Setter Property="ContentId" Value="{Binding Model.ContentId}"/>
                        <Setter Property="IsSelected" Value="{Binding Model.IsSelected, Mode=TwoWay}"/>
                        <Setter Property="IsActive" Value="{Binding Model.IsActive, Mode=TwoWay}"/>
                    </Style>
                </utilities1:PanesStyleSelector.WebUIStyle>
                <utilities1:PanesStyleSelector.DocumentStyle>
                    <Style TargetType="{x:Type avalonDock:LayoutItem}">
                        <Setter Property="Title" Value="{Binding Model.WorkflowName}" />
                        <Setter Property="IsActive" Value="{Binding Model.IsActive}" />
                        <Setter Property="IsSelected" Value="{Binding Model.IsActive}" />
                    </Style>
                </utilities1:PanesStyleSelector.DocumentStyle>
            </utilities1:PanesStyleSelector>
        </avalonDock:DockingManager.LayoutItemContainerStyleSelector>

        <avalonDock:DockingManager.LayoutItemTemplateSelector>
            <utilities1:PanesTemplateSelector>
                <utilities1:PanesTemplateSelector.WorkflowDesignerViewTemplate>
                    <DataTemplate>
                        <ContentControl cal:View.Model="{Binding}" IsTabStop="False" />
                    </DataTemplate>
                </utilities1:PanesTemplateSelector.WorkflowDesignerViewTemplate>
                <utilities1:PanesTemplateSelector.WebUIViewTemplate>
                    <DataTemplate>
                        <ContentControl cal:View.Model="{Binding}" IsTabStop="False" />
                    </DataTemplate>
                </utilities1:PanesTemplateSelector.WebUIViewTemplate>
            </utilities1:PanesTemplateSelector> 
        </avalonDock:DockingManager.LayoutItemTemplateSelector>

        <avalonDock:LayoutRoot>
            <avalonDock:LayoutPanel Orientation="Horizontal">
                <avalonDock:LayoutDocumentPaneGroup>
                    <avalonDock:LayoutDocumentPane AutomationProperties.AutomationId="AvalonDocumentPane"/>
                </avalonDock:LayoutDocumentPaneGroup>
                <avalonDock:LayoutAnchorablePane DockWidth="800" DockMinWidth="400" AutomationProperties.AutomationId="WebUIPane"/>
                <avalonDock:LayoutAnchorablePane DockWidth="225" DockMinWidth="225" AutomationProperties.AutomationId="ActivitiesPane">
                    <avalonDock:LayoutAnchorable Title="Activities" AutoHideWidth="225" AutoHideMinWidth="225" CanClose="False" CanHide="False">
                        <toolbox:ToolboxControl Name="Toolbox" AutomationProperties.AutomationId="ActivitiesToolbox"
                                                        utilities1:ToolboxItemSource.ToolboxItems="{Binding ToolboxList}" />
                    </avalonDock:LayoutAnchorable>
                </avalonDock:LayoutAnchorablePane>
            </avalonDock:LayoutPanel>
        </avalonDock:LayoutRoot>

    </avalonDock:DockingManager>

Answer 1

Although I didn't find a direct way of preventing the docking, I was able to get the basic problem fixed, namely customizing different tab headers for tool windows and document windows. My document windows show asterisk (*) in the tab header to indicate changes (just like VS), whereas the tool windows should not do so.

The solution was to use DocumentHeaderTemplateSelector and provide it with two different templates, one each for documents and tool windows. Here's the XAML:

<xcad:DockingManager.DocumentHeaderTemplateSelector>
  <bd:DocumentHeaderTemplateSelector>
    <bd:DocumentHeaderTemplateSelector.DocumentTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <Image Source="Resources\AppIcon.ico" Margin="0,0,4,0" Width="16" />
          <TextBlock Text="{Binding Title}" />
          <TextBlock Text=" *" Visibility="{Binding Content.IsDirty, Converter={StaticResource BoolToVisibilityConverter}}" />
        </StackPanel>
      </DataTemplate>
    </bd:DocumentHeaderTemplateSelector.DocumentTemplate>
    <bd:DocumentHeaderTemplateSelector.ToolWindowTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <TextBlock Text="{Binding Title}" />
        </StackPanel>
      </DataTemplate>
    </bd:DocumentHeaderTemplateSelector.ToolWindowTemplate>
  </bd:DocumentHeaderTemplateSelector>
</xcad:DockingManager.DocumentHeaderTemplateSelector>

The selector class is simply:

Public Class DocumentHeaderTemplateSelector
  Inherits DataTemplateSelector

  Public Property DocumentTemplate As DataTemplate
  Public Property ToolWindowTemplate As DataTemplate

  Public Overrides Function SelectTemplate(item As Object, container As System.Windows.DependencyObject) As System.Windows.DataTemplate
    Dim itemAsLayoutContent = TryCast(item, Xceed.Wpf.AvalonDock.Layout.LayoutContent)

    If TypeOf item Is Xceed.Wpf.AvalonDock.Layout.LayoutDocument AndAlso TypeOf DirectCast(item, Xceed.Wpf.AvalonDock.Layout.LayoutDocument).Content Is DocumentVM Then
      Return DocumentTemplate
    Else
      Return ToolWindowTemplate
    End If
  End Function
End Class

Now my tool windows do not show asterisk (*) and icon even if they are moved into the documents pane.

Hope this helps someone down the road.