added AP to be able to swap between a scrollable and a wrapping header panel in a TabControl (#3952)

Author: corvinsz

src/MainDemo.Wpf/Domain/TabsViewModel.cs

@@ -4,10 +4,10 @@
 
 namespace MaterialDesignDemo.Domain;
 
-internal class TabsViewModel : ViewModelBase
+internal partial class TabsViewModel : ObservableObject
 {
     public ObservableCollection<CustomTab> CustomTabs { get; }
-
+    public List<int> LongList { get; }
     public CustomTab? SelectedTab { get; set; }
 
     public string? VeryLongText { get; set; } = @"
@@ -47,6 +47,8 @@ public TabsViewModel()
                 CustomContent = "Custom content 3",
             },
         };
+
+        LongList = Enumerable.Range(1, 20).ToList();
     }
 
 }

src/MainDemo.Wpf/Tabs.xaml

@@ -755,5 +755,87 @@
       </materialDesign:Card>
     </smtx:XamlDisplay>
 
+    <Border Width="720"
+        BorderBrush="{DynamicResource MaterialDesign.Brush.Primary}"
+        BorderThickness="1">
+      <Grid>
+        <Grid.RowDefinitions>
+          <RowDefinition Height="auto" />
+          <RowDefinition Height="*" />
+        </Grid.RowDefinitions>
+        <Grid.ColumnDefinitions>
+          <ColumnDefinition Width="*" MinWidth="50" />
+          <ColumnDefinition Width="2" />
+          <ColumnDefinition Width="*" MinWidth="50" />
+        </Grid.ColumnDefinitions>
+
+        <materialDesign:ColorZone Grid.ColumnSpan="2"
+                              Padding="8"
+                              Mode="PrimaryMid">
+          <TextBlock Text="materialDesign:TabAssist.HeaderBehavior=&quot;Scrolling&quot;" />
+        </materialDesign:ColorZone>
+
+        <materialDesign:ColorZone Grid.Column="2"
+                              Padding="8"
+                              Mode="PrimaryMid">
+          <TextBlock Text="materialDesign:TabAssist.HeaderBehavior=&quot;Wrapping&quot;" />
+        </materialDesign:ColorZone>
+
+        <smtx:XamlDisplay Grid.Row="1"
+                      Grid.Column="0"
+                      Margin="16"
+                      UniqueKey="tabs_tabAssist_1">
+          <TabControl materialDesign:TabAssist.HeaderBehavior="Scrolling"
+                  ItemsSource="{Binding LongList}"
+                  Style="{StaticResource MaterialDesignTabControl}">
+            <TabControl.ItemTemplate>
+              <DataTemplate>
+                <StackPanel Orientation="Horizontal">
+                  <TextBlock Text="{Binding ., StringFormat=Header {0}}" />
+                </StackPanel>
+              </DataTemplate>
+            </TabControl.ItemTemplate>
+            <TabControl.ContentTemplate>
+              <DataTemplate>
+                <TextBlock Margin="10"
+                       FontSize="18"
+                       Text="{Binding ., StringFormat=Content {0}}" />
+              </DataTemplate>
+            </TabControl.ContentTemplate>
+          </TabControl>
+        </smtx:XamlDisplay>
+
+        <GridSplitter Grid.RowSpan="2"
+                  Grid.Column="1"
+                  HorizontalAlignment="Stretch"
+                  VerticalAlignment="Stretch" />
+
+        <smtx:XamlDisplay Grid.Row="1"
+                      Grid.Column="2"
+                      Margin="16"
+                      UniqueKey="tabs_tabAssist_2">
+          <TabControl materialDesign:TabAssist.HeaderBehavior="Wrapping"
+                  ItemsSource="{Binding LongList}"
+                  Style="{StaticResource MaterialDesignTabControl}">
+            <TabControl.ItemTemplate>
+              <DataTemplate>
+                <StackPanel Orientation="Horizontal">
+                  <TextBlock Text="{Binding ., StringFormat=Header {0}}" />
+                </StackPanel>
+              </DataTemplate>
+            </TabControl.ItemTemplate>
+            <TabControl.ContentTemplate>
+              <DataTemplate>
+                <TextBlock Margin="10"
+                       FontSize="18"
+                       Text="{Binding ., StringFormat=Content {0}}" />
+              </DataTemplate>
+            </TabControl.ContentTemplate>
+          </TabControl>
+        </smtx:XamlDisplay>
+
+      </Grid>
+    </Border>
+
   </StackPanel>
 </UserControl>

src/MaterialDesignThemes.Wpf/TabAssist.cs

@@ -1,5 +1,10 @@
 namespace MaterialDesignThemes.Wpf;
 
+public enum TabControlHeaderBehavior
+{
+    Scrolling,
+    Wrapping
+}
 public static class TabAssist
 {
     public static readonly DependencyProperty HasFilledTabProperty = DependencyProperty.RegisterAttached(
@@ -54,4 +59,14 @@ public static void SetTabHeaderCursor(DependencyObject obj, Cursor value)
 
     public static readonly DependencyProperty TabHeaderCursorProperty =
         DependencyProperty.RegisterAttached("TabHeaderCursor", typeof(Cursor), typeof(TabAssist), new PropertyMetadata(Cursors.Hand));
+
+    public static TabControlHeaderBehavior GetHeaderBehavior(DependencyObject obj)
+        => (TabControlHeaderBehavior)obj.GetValue(HeaderBehaviorProperty);
+
+    public static void SetHeaderBehavior(DependencyObject obj, TabControlHeaderBehavior value)
+        => obj.SetValue(HeaderBehaviorProperty, value);
+
+    public static readonly DependencyProperty HeaderBehaviorProperty =
+        DependencyProperty.RegisterAttached("HeaderBehavior", typeof(TabControlHeaderBehavior), typeof(TabAssist),
+            new PropertyMetadata(TabControlHeaderBehavior.Scrolling));
 }