optimized tab switching logic

src/Shared/HandyControl_Shared/Controls/Ribbon/Ribbon.cs

@@ -4,6 +4,7 @@ using System.Collections.Specialized;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
+using System.Windows.Input;
 
 namespace HandyControl.Controls
 {
@@ -51,7 +52,7 @@ namespace HandyControl.Controls
             InitializeSelection();
         }
 
-        internal void NotifyMouseClickedOnTabHeader(RibbonTabHeader tabHeader)
+        internal void NotifyMouseClickedOnTabHeader(RibbonTabHeader tabHeader, MouseButtonEventArgs e)
         {
             if (_tabHeaderItemsControl == null)
             {
@@ -110,11 +111,6 @@ namespace HandyControl.Controls
                 return;
             }
 
-            if (e.RemovedItems.Count > 0 && ItemContainerGenerator.ContainerFromItem(e.RemovedItems[0]) is RibbonTab oldRibbonTab)
-            {
-                oldRibbonTab.IsSelected = false;
-            }
-
             SelectedItem = e.AddedItems[0];
         }
 

src/Shared/HandyControl_Shared/Controls/Ribbon/RibbonTab.cs

@@ -36,8 +36,13 @@ namespace HandyControl.Controls
             VisibilityProperty.OverrideMetadata(typeof(RibbonTab), new PropertyMetadata(Visibility.Visible, OnVisibilityChanged));
         }
 
-        public static readonly DependencyProperty IsSelectedProperty = DependencyProperty.Register(
-            "IsSelected", typeof(bool), typeof(RibbonTab), new PropertyMetadata(ValueBoxes.FalseBox, OnIsSelectedChanged));
+        public static readonly DependencyProperty IsSelectedProperty =
+            Selector.IsSelectedProperty.AddOwner(typeof(RibbonTab),
+                new FrameworkPropertyMetadata(ValueBoxes.FalseBox,
+                    FrameworkPropertyMetadataOptions.AffectsParentMeasure |
+                    FrameworkPropertyMetadataOptions.BindsTwoWayByDefault |
+                    FrameworkPropertyMetadataOptions.Journal,
+                    OnIsSelectedChanged));
 
         private static void OnIsSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {

src/Shared/HandyControl_Shared/Controls/Ribbon/RibbonTabHeader.cs

@@ -46,6 +46,11 @@ namespace HandyControl.Controls
             set => SetValue(IsSelectedProperty, value);
         }
 
+        internal void PrepareRibbonTabHeader()
+        {
+            CoerceValue(IsSelectedProperty);
+        }
+
         protected virtual void OnIsSelectedChanged(bool oldIsSelected, bool newIsSelected)
         {
             
@@ -53,10 +58,27 @@ namespace HandyControl.Controls
 
         protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
         {
-            base.OnMouseLeftButtonDown(e);
+            var ribbon = Ribbon;
+            if (ribbon != null)
+            {
+                ribbon.NotifyMouseClickedOnTabHeader(this, e);
+                e.Handled = true;
+            }
 
-            Ribbon.NotifyMouseClickedOnTabHeader(this);
-            RibbonTab.IsSelected = true;
+            base.OnMouseLeftButtonDown(e);
+        }
+
+        protected override void OnGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
+        {
+            base.OnGotKeyboardFocus(e);
+
+            var ribbonTab = RibbonTab;
+            if (ribbonTab == null)
+            {
+                return;
+            }
+
+            ribbonTab.IsSelected = true;
         }
     }
 }

src/Shared/HandyControl_Shared/Controls/Ribbon/RibbonTabHeaderItemsControl.cs

@@ -8,5 +8,15 @@ namespace HandyControl.Controls
         protected override DependencyObject GetContainerForItemOverride() => new RibbonTabHeader();
 
         protected override bool IsItemItsOwnContainerOverride(object item) => item is RibbonTabHeader;
+
+        protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
+        {
+            base.PrepareContainerForItemOverride(element, item);
+
+            if (element is RibbonTabHeader ribbonTabHeader)
+            {
+                ribbonTabHeader.PrepareRibbonTabHeader();
+            }
+        }
     }
 }

src/Shared/HandyControl_Shared/Themes/Styles/Ribbon.xaml

@@ -6,6 +6,7 @@
     <Geometry x:Key="DialogBoxLauncherGeometry">M0,0 8,0 8,1 1,1 1,8 0,8 M 3.7,3 8,7.3 8,4 9,4 9,9 4,9 4,8 7.3,8 3,3.7</Geometry>
 
     <Style TargetType="hc:RibbonGroup">
+        <Setter Property="Focusable" Value="False"/>
         <Setter Property="Height" Value="95"/>
         <Setter Property="BorderBrush" Value="{DynamicResource BorderBrush}"/>
         <Setter Property="Padding" Value="6"/>
@@ -73,6 +74,7 @@
     </Style>
 
     <Style TargetType="hc:RibbonTab">
+        <Setter Property="Focusable" Value="False"/>
         <Setter Property="VerticalContentAlignment" Value="Center"/>
         <Setter Property="ItemsPanel">
             <Setter.Value>
@@ -94,6 +96,7 @@
     </Style>
 
     <Style TargetType="hc:Ribbon">
+        <Setter Property="Focusable" Value="False"/>
         <Setter Property="Background" Value="{DynamicResource RegionBrush}"/>
         <Setter Property="BorderThickness" Value="0"/>
         <Setter Property="BorderBrush" Value="{DynamicResource BorderBrush}"/>
@@ -123,7 +126,7 @@
                                 <DropShadowEffect BlurRadius="8" ShadowDepth="2" Direction="-90" Color="{StaticResource EffectShadowColor}" Opacity=".1" RenderingBias="Performance"/>
                             </Border.Effect>
                         </Border>
-                        <hc:RibbonTabHeaderItemsControl Grid.Row="0" Grid.Column="0" x:Name="PART_TabHeaderItemsControl" Margin="10,0,10,2">
+                        <hc:RibbonTabHeaderItemsControl Focusable="False" Grid.Row="0" Grid.Column="0" x:Name="PART_TabHeaderItemsControl" Margin="10,0,10,2">
                             <ItemsControl.ItemsPanel>
                                 <ItemsPanelTemplate>
                                     <hc:SimpleStackPanel Orientation="Horizontal"/>