Fix that Backstage.IsOpen is not bindable

Fluent.Ribbon.Showcase/TestContent.xaml

@@ -176,7 +176,8 @@
                 <Grid>
                     <!-- Backstage items can be keytipped -->
                     <Fluent:Backstage x:Name="Backstage"
-                                      Visibility="Collapsed">
+                                      Visibility="Collapsed"
+                                      IsOpen="{Binding IsBackstageOpen, Mode=TwoWay}">
 
                         <!--<Fluent:Backstage.Style>
                             <Style TargetType="Fluent:Backstage">
@@ -3213,6 +3214,12 @@
                                                        Size="Middle">
                                             Show start screen
                                         </Fluent:Button>
+
+                                        <Fluent:CheckBox x:Name="BackstageOpenBinding"
+                                                         IsChecked="{Binding IsBackstageOpen}"
+                                                         Visibility="{Binding ElementName=Backstage, Path=Visibility}">
+                                            Is backstage open binding
+                                        </Fluent:CheckBox>
                                     </WrapPanel>
                                 </GroupBox>
 

Fluent.Ribbon.Showcase/ViewModels/MainViewModel.cs

@@ -37,6 +37,7 @@ public class MainViewModel : ViewModel
     private bool? isCheckedToggleButton3 = true;
 
     private bool areContextGroupsVisible = true;
+    private bool isBackstageOpen = false;
 
     public MainViewModel()
     {
@@ -95,6 +96,21 @@ public bool AreContextGroupsVisible
         }
     }
 
+    public bool IsBackstageOpen
+    {
+        get => this.isBackstageOpen;
+        set
+        {
+            if (value == this.isBackstageOpen)
+            {
+                return;
+            }
+
+            this.isBackstageOpen = value;
+            this.OnPropertyChanged();
+        }
+    }
+
     public ColorViewModel ColorViewModel
     {
         get { return this.colorViewModel; }

Fluent.Ribbon/Automation/Peers/RibbonBackstageAutomationPeer.cs

@@ -62,13 +62,13 @@ protected override List<AutomationPeer> GetChildrenCore()
     /// <inheritdoc />
     void IExpandCollapseProvider.Collapse()
     {
-        this.OwningBackstage.IsOpen = false;
+        this.OwningBackstage.SetIsOpen(false);
     }
 
     /// <inheritdoc />
     void IExpandCollapseProvider.Expand()
     {
-        this.OwningBackstage.IsOpen = true;
+        this.OwningBackstage.SetIsOpen(true);
     }
 
     /// <inheritdoc />

Fluent.Ribbon/Controls/Backstage.cs

@@ -42,6 +42,8 @@ public class Backstage : RibbonControl
     /// <remarks>This is exposed to make it possible to show content on the same <see cref="AdornerLayer"/> as the backstage is shown on.</remarks>
     public AdornerLayer? AdornerLayer { get; private set; }
 
+    #region IsOpen
+
     /// <summary>
     /// Gets or sets whether backstage is shown
     /// </summary>
@@ -55,6 +57,50 @@ public bool IsOpen
     public static readonly DependencyProperty IsOpenProperty =
         DependencyProperty.Register(nameof(IsOpen), typeof(bool), typeof(Backstage), new PropertyMetadata(BooleanBoxes.FalseBox, OnIsOpenChanged, CoerceIsOpen));
 
+    private static object? CoerceIsOpen(DependencyObject d, object? baseValue)
+    {
+        var backstage = (Backstage)d;
+
+        if (backstage.CanChangeIsOpen == false)
+        {
+            return BooleanBoxes.Box(backstage.IsOpen);
+        }
+
+        return baseValue;
+    }
+
+    private static void OnIsOpenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        var control = (Backstage)d;
+
+        var oldValue = (bool)e.OldValue;
+        var newValue = (bool)e.NewValue;
+
+        lock (syncIsOpen)
+        {
+            if ((bool)e.NewValue)
+            {
+                control.Show();
+            }
+            else
+            {
+                control.Hide();
+            }
+
+            // Invoke the event
+            control.IsOpenChanged?.Invoke(control, e);
+        }
+
+        (UIElementAutomationPeer.FromElement(control) as Fluent.Automation.Peers.RibbonBackstageAutomationPeer)?.RaiseExpandCollapseAutomationEvent(oldValue, newValue);
+    }
+
+    internal void SetIsOpen(bool isOpen)
+    {
+        this.SetCurrentValue(IsOpenProperty, BooleanBoxes.Box(isOpen));
+    }
+
+    #endregion
+
     /// <summary>
     /// Gets or sets whether backstage can be openend or closed.
     /// </summary>
@@ -107,43 +153,6 @@ public bool CloseOnEsc
     public static readonly DependencyProperty CloseOnEscProperty =
         DependencyProperty.Register(nameof(CloseOnEsc), typeof(bool), typeof(Backstage), new PropertyMetadata(BooleanBoxes.TrueBox));
 
-    private static object? CoerceIsOpen(DependencyObject d, object? baseValue)
-    {
-        var backstage = (Backstage)d;
-
-        if (backstage.CanChangeIsOpen == false)
-        {
-            return BooleanBoxes.Box(backstage.IsOpen);
-        }
-
-        return baseValue;
-    }
-
-    private static void OnIsOpenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-    {
-        var control = (Backstage)d;
-
-        var oldValue = (bool)e.OldValue;
-        var newValue = (bool)e.NewValue;
-
-        lock (syncIsOpen)
-        {
-            if ((bool)e.NewValue)
-            {
-                control.Show();
-            }
-            else
-            {
-                control.Hide();
-            }
-
-            // Invoke the event
-            control.IsOpenChanged?.Invoke(control, e);
-        }
-
-        (UIElementAutomationPeer.FromElement(control) as Fluent.Automation.Peers.RibbonBackstageAutomationPeer)?.RaiseExpandCollapseAutomationEvent(oldValue, newValue);
-    }
-
     /// <summary>Identifies the <see cref="UseHighestAvailableAdornerLayer"/> dependency property.</summary>
     public static readonly DependencyProperty UseHighestAvailableAdornerLayerProperty = DependencyProperty.Register(nameof(UseHighestAvailableAdornerLayer), typeof(bool), typeof(Backstage), new PropertyMetadata(BooleanBoxes.TrueBox));
 
@@ -278,7 +287,7 @@ protected virtual void OnDismissPopup(object? sender, DismissPopupEventArgs e)
             return;
         }
 
-        this.IsOpen = false;
+        this.SetIsOpen(false);
     }
 
     #endregion
@@ -288,7 +297,7 @@ protected virtual void OnDismissPopup(object? sender, DismissPopupEventArgs e)
     // Handles click event
     private void Click()
     {
-        this.IsOpen = !this.IsOpen;
+        this.SetIsOpen(!this.IsOpen);
     }
 
     #region Show / Hide
@@ -512,7 +521,7 @@ private static void HandleOpenBackstageCommandCanExecute(object sender, CanExecu
     private static void HandleOpenBackstageCommandExecuted(object sender, ExecutedRoutedEventArgs args)
     {
         var target = ((BackstageAdorner)args.Source).Backstage;
-        target.IsOpen = !target.IsOpen;
+        target.SetIsOpen(!target.IsOpen);
     }
 
     private void CreateAndAttachBackstageAdorner()
@@ -690,7 +699,7 @@ private void HandleOwnerWindowSizeChanged(object sender, SizeChangedEventArgs e)
 
     private void HandleTabControlRequestBackstageClose(object? sender, EventArgs e)
     {
-        this.IsOpen = false;
+        this.SetIsOpen(false);
     }
 
     // We have to collapse WindowsFormsHost while Backstage is open
@@ -729,7 +738,7 @@ protected override void OnKeyDown(KeyEventArgs e)
         {
             if (this.IsFocused)
             {
-                this.IsOpen = !this.IsOpen;
+                this.SetIsOpen(!this.IsOpen);
                 e.Handled = true;
             }
         }
@@ -749,7 +758,7 @@ private void HandleOwnerWindowKeyDown(object sender, KeyEventArgs e)
         // only handle ESC when the backstage is open
         e.Handled = this.IsOpen;
 
-        this.IsOpen = false;
+        this.SetIsOpen(false);
     }
 
     private void OnBackstageLoaded(object sender, RoutedEventArgs e)
@@ -786,7 +795,7 @@ protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
     /// <inheritdoc />
     public override KeyTipPressedResult OnKeyTipPressed()
     {
-        this.IsOpen = true;
+        this.SetIsOpen(true);
         base.OnKeyTipPressed();
 
         return KeyTipPressedResult.Empty;
@@ -795,7 +804,7 @@ public override KeyTipPressedResult OnKeyTipPressed()
     /// <inheritdoc />
     public override void OnKeyTipBack()
     {
-        this.IsOpen = false;
+        this.SetIsOpen(false);
         base.OnKeyTipBack();
     }