Disable scroll chaining for ScrollVIewers in popup. (#20503)

* feat: disable scroll chaining for AutoCompleteBox, ComboBox, and MenuScrollViewer.

* feat: disable scroll chaining for AutoCompleteBox, ComboBox, and MenuFlyoutPresenter

* feat: enable scroll chaining for ScrollViewer in MenuFlyoutPresenter.

src/Avalonia.Themes.Fluent/Controls/AutoCompleteBox.xaml

@@ -66,7 +66,8 @@
                          BorderThickness="0"
                          Background="Transparent"
                          ItemTemplate="{TemplateBinding ItemTemplate}"
-                         Margin="{DynamicResource AutoCompleteListPadding}" />
+                         Margin="{DynamicResource AutoCompleteListPadding}"
+                         ScrollViewer.IsScrollChainingEnabled="False" />
               </Border>
             </Popup>
           </Grid>

src/Avalonia.Themes.Fluent/Controls/ComboBox.xaml

@@ -172,6 +172,7 @@
                       HorizontalAlignment="Stretch"
                       CornerRadius="{DynamicResource OverlayCornerRadius}">
                 <ScrollViewer HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
+                              IsScrollChainingEnabled="False"
                               VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                               IsDeferredScrollingEnabled="{TemplateBinding (ScrollViewer.IsDeferredScrollingEnabled)}">
                   <ItemsPresenter Name="PART_ItemsPresenter"

src/Avalonia.Themes.Fluent/Controls/MenuScrollViewer.xaml

@@ -21,6 +21,7 @@
 
   <ControlTheme x:Key="FluentMenuScrollViewer" TargetType="ScrollViewer">
     <Setter Property="Background" Value="Transparent" />
+    <Setter Property="IsScrollChainingEnabled" Value="False" />
     <Setter Property="Template">
       <ControlTemplate>
         <DockPanel>

src/Avalonia.Themes.Simple/Controls/AutoCompleteBox.xaml

@@ -38,6 +38,7 @@
                        BorderThickness="0"
                        Foreground="{TemplateBinding Foreground}"
                        ItemTemplate="{TemplateBinding ItemTemplate}"
+                       ScrollViewer.IsScrollChainingEnabled="False"
                        ScrollViewer.HorizontalScrollBarVisibility="Auto"
                        ScrollViewer.VerticalScrollBarVisibility="Auto" />
             </Border>

src/Avalonia.Themes.Simple/Controls/ComboBox.xaml

@@ -87,7 +87,8 @@
                       BorderThickness="1">
                 <ScrollViewer HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                               VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
-                              IsDeferredScrollingEnabled="{TemplateBinding (ScrollViewer.IsDeferredScrollingEnabled)}">
+                              IsDeferredScrollingEnabled="{TemplateBinding (ScrollViewer.IsDeferredScrollingEnabled)}"
+                              ScrollViewer.IsScrollChainingEnabled="False">
                   <ItemsPresenter Name="PART_ItemsPresenter"
                                   ItemsPanel="{TemplateBinding ItemsPanel}" />
                 </ScrollViewer>

src/Avalonia.Themes.Simple/Controls/ScrollViewer.xaml

@@ -40,6 +40,7 @@
   <ControlTheme x:Key="SimpleMenuScrollViewer"
                 TargetType="ScrollViewer">
     <Setter Property="Background" Value="Transparent" />
+    <Setter Property="IsScrollChainingEnabled" Value="False" />
     <Setter Property="Template">
       <ControlTemplate>
         <DockPanel>