Add x:ClassModifier="internal" to all theme xaml files that should be hidden

src/Avalonia.Themes.Fluent/Accents/BaseColorsPalette.xaml

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <!-- https://docs.microsoft.com/en-us/previous-versions/windows/apps/dn518235(v=win.10)?redirectedfrom=MSDN -->
   <ResourceDictionary.ThemeDictionaries>
     <ResourceDictionary x:Key="Default">

src/Avalonia.Themes.Fluent/Accents/BaseResources.xaml

@@ -1,7 +1,8 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:sys="using:System"
-                    xmlns:converters="using:Avalonia.Controls.Converters">
+                    xmlns:converters="using:Avalonia.Controls.Converters"
+                    x:ClassModifier="internal">
   <FontFamily x:Key="ContentControlThemeFontFamily">fonts:Inter#Inter, $Default</FontFamily>
   <sys:Double x:Key="ControlContentThemeFontSize">14</sys:Double>
 

src/Avalonia.Themes.Fluent/Accents/FluentControlResources.xaml

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ResourceDictionary.ThemeDictionaries>
     <ResourceDictionary x:Key="Default">
       <!-- Resources for Button.xaml -->

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Thickness x:Key="SystemControlFocusVisualMargin">0</Thickness>
   <Thickness x:Key="SystemControlFocusVisualPrimaryThickness">2</Thickness>
   <Thickness x:Key="SystemControlFocusVisualSecondaryThickness">1</Thickness>

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:generic="using:System.Collections.Generic">
+                    xmlns:generic="using:System.Collections.Generic"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <AutoCompleteBox Width="200">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,7 +1,8 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:sys="using:System"
-                    xmlns:converters="using:Avalonia.Controls.Converters">
+                    xmlns:converters="using:Avalonia.Controls.Converters"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <Calendar />

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

@@ -5,7 +5,8 @@
 // All other rights reserved.
 -->
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Margin="20, 20, 20, 200">
       <CalendarDatePicker Width="200" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" />

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

@@ -5,7 +5,8 @@
 // All other rights reserved.
 -->
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -6,7 +6,8 @@
 -->
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:sys="using:System">
+        xmlns:sys="using:System"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <Calendar DisplayDate="2000-01-01">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Carousel}" TargetType="Carousel">
     <Setter Property="Template">
       <ControlTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="10">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <Border Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="{DynamicResource ComboBoxDropdownBorderThickness}" Margin="0,-1,0,-1" Padding="{DynamicResource ComboBoxDropdownBorderPadding}" CornerRadius="{DynamicResource OverlayCornerRadius}">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ContentControl}" TargetType="ContentControl">
     <Setter Property="Template">
       <ControlTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Background="{DynamicResource SystemAccentColor}"
             Margin="16"

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

@@ -1,7 +1,8 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:sys="using:System"
-                    xmlns:collections="using:System.Collections">
+                    xmlns:collections="using:System.Collections"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -7,7 +7,8 @@
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:sys="using:System">
+        xmlns:sys="using:System"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20" Height="500">
       <StackPanel Spacing="20" VerticalAlignment="Center">

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20" Width="200">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
     <Design.PreviewWith>
       <Border Padding="20">
         <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type EmbeddableControlRoot}" TargetType="EmbeddableControlRoot">
     <Setter Property="Foreground" Value="{DynamicResource SystemControlForegroundBaseHighBrush}"/>
     <Setter Property="Background" Value="{DynamicResource SystemRegionBrush}"/>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
 
   <Design.PreviewWith>
     <Border Padding="20">

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

@@ -1,6 +1,7 @@
 <Styles
     xmlns="https://github.com/avaloniaui"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    x:ClassModifier="internal">
     <Styles.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Thickness x:Key="FlyoutBorderThemeThickness">1</Thickness>
   <ControlTheme x:Key="{x:Type FlyoutPresenter}" TargetType="FlyoutPresenter">
     <Setter Property="HorizontalContentAlignment" Value="Stretch" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
     <ControlTheme x:Key="{x:Type GridSplitter}" TargetType="GridSplitter">
       <Setter Property="Focusable" Value="True" />
       <Setter Property="MinWidth" Value="6" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ItemsControl}" TargetType="ItemsControl">
     <Setter Property="Template">
       <ControlTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
 
   <ControlTheme x:Key="{x:Type Label}" TargetType="Label">
     <Setter Property="Padding" Value="3"/>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <ListBox>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="0">
       <ListBox>

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

@@ -1,7 +1,8 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:dialogs="using:Avalonia.Dialogs"
-        xmlns:internal="using:Avalonia.Dialogs.Internal">
+        xmlns:internal="using:Avalonia.Dialogs.Internal"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20" Width="800" Height="500">
       <dialogs:ManagedFileChooser/>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <Menu>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type MenuFlyoutPresenter}" TargetType="MenuFlyoutPresenter">
     <Setter Property="Background" Value="{DynamicResource MenuFlyoutPresenterBackground}" />
     <Setter Property="BorderBrush" Value="{DynamicResource MenuFlyoutPresenterBorderBrush}" />

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:conv="using:Avalonia.Controls.Converters">
+                    xmlns:conv="using:Avalonia.Controls.Converters"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20" Width="320">
       <StackPanel Spacing="20" HorizontalAlignment="Left">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:converters="using:Avalonia.Controls.Converters">
+                    xmlns:converters="using:Avalonia.Controls.Converters"
+                    x:ClassModifier="internal">
 
   <Design.PreviewWith>
     <ScrollViewer Theme="{DynamicResource FluentMenuScrollViewer}" Width="200" Height="200">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:local="using:Avalonia.Themes.Fluent">
+                    xmlns:local="using:Avalonia.Themes.Fluent"
+                    x:ClassModifier="internal">
   <local:IBitmapToImageConverter x:Key="AvaloniaThemesFluentNativeMenuBarIBitmapToImageConverter"/>
   <ControlTheme x:Key="{x:Type NativeMenuBar}" TargetType="NativeMenuBar">
     <Setter Property="Template">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="0" Background="White">
       <NotificationCard Content="Testing" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type OverlayPopupHost}" TargetType="OverlayPopupHost">
     <Setter Property="Foreground" Value="{DynamicResource SystemControlForegroundBaseHighBrush}"/>
     <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}"/>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <StackPanel>
       <StackPanel.Resources>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type PopupRoot}" TargetType="PopupRoot">
     <Setter Property="Background" Value="{x:Null}" />
     <Setter Property="TransparencyLevelHint" Value="Transparent" />

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:converters="using:Avalonia.Controls.Converters">
+                    xmlns:converters="using:Avalonia.Controls.Converters"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Orientation="Horizontal" Spacing="10">

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

@@ -1,4 +1,5 @@
-<ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+<ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="10">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type RefreshContainer}"
                 TargetType="RefreshContainer">
     <Setter Property="Template">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type RefreshVisualizer}"
                 TargetType="RefreshVisualizer">
     <Setter Property="IsTabStop" Value="False"/>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Orientation="Horizontal" Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary
   xmlns="https://github.com/avaloniaui"
-  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+  x:ClassModifier="internal">
   <Design.PreviewWith>
     <ScrollViewer Width="200" Height="200"
                   HorizontalScrollBarVisibility="Auto">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <SelectableTextBlock Text="Preview" />
   </Design.PreviewWith>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Separator}" TargetType="Separator">
     <Setter Property="Background" Value="{DynamicResource SystemControlForegroundBaseMediumLowBrush}" />
     <Setter Property="Focusable" Value="False" />

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Margin="20" Width="400" Height="600">
       <DockPanel LastChildFill="True">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:converters="using:Avalonia.Controls.Converters">
+        xmlns:converters="using:Avalonia.Controls.Converters"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="60">
       <StackPanel Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:sys="using:System">
+        xmlns:sys="using:System"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Width="400" Height="400">
       <SplitView DisplayMode="Inline"

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Width="400">
       <TabControl>

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

@@ -1,6 +1,7 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <TabStrip>

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

@@ -1,6 +1,7 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ThemeVariantScope}"
                 TargetType="ThemeVariantScope">
     <Setter Property="TextElement.Foreground" Value="{DynamicResource SystemControlForegroundBaseHighBrush}"/>

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

@@ -7,7 +7,8 @@
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:sys="using:System">
+        xmlns:sys="using:System"
+        x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20" Height="500">
       <StackPanel Spacing="20" VerticalAlignment="Center">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
     <Design.PreviewWith>
       <Border Height="30" Width="300">
         <TitleBar Background="SkyBlue" Foreground="Black" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    x:ClassModifier="internal">
   <Design.PreviewWith>
     <StackPanel Margin="20" Width="250" Spacing="24">
       <StackPanel Spacing="12" >

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type TransitioningContentControl}" TargetType="TransitioningContentControl">
     <Setter Property="Template">
       <ControlTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-        xmlns:converters="using:Avalonia.Controls.Converters">
+        xmlns:converters="using:Avalonia.Controls.Converters"
+        x:ClassModifier="internal">
 
   <Design.PreviewWith>
     <Border Padding="20"

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

@@ -1,6 +1,7 @@
 <Style xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-       Selector=":is(UserControl)">
+       Selector=":is(UserControl)"
+       x:ClassModifier="internal">
   <Style.Resources>
     <ControlTheme x:Key="FluentUserControl" TargetType="UserControl">
       <Setter Property="Template">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Window}" TargetType="Window">
     <Setter Property="Background" Value="{DynamicResource SystemRegionBrush}"/>
     <Setter Property="TransparencyBackgroundFallback" Value="{DynamicResource SystemControlBackgroundAltHighBrush}" />

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

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    x:DataType="WindowNotificationManager">
+                    x:DataType="WindowNotificationManager"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type WindowNotificationManager}" TargetType="WindowNotificationManager">
     <Setter Property="Margin" Value="0 0" />
     <Setter Property="Template">

src/Avalonia.Themes.Fluent/DensityStyles/Compact.xaml

@@ -1,5 +1,6 @@
 <Styles xmlns="https://github.com/avaloniaui" 
-        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        x:ClassModifier="internal">
     <Style Selector="TextBlock" >
         <Setter Property="FontSize" Value="14" />
     </Style>

src/Avalonia.Themes.Fluent/FluentTheme.xaml

@@ -2,7 +2,7 @@
         xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:fluent="using:Avalonia.Themes.Fluent"
-        xmlns:accents="clr-namespace:Avalonia.Themes.Fluent.Accents">
+        xmlns:accents="using:Avalonia.Themes.Fluent.Accents">
   <Styles.Resources>
     <ResourceDictionary>
       <ResourceDictionary.MergedDictionaries>

src/Avalonia.Themes.Simple/Accents/Base.xaml

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <ResourceDictionary.ThemeDictionaries>
     <ResourceDictionary x:Key="Default">
       <Color x:Key="ThemeBackgroundColor">#FFFFFFFF</Color>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type AdornerLayer}" TargetType="AdornerLayer">
     <Setter Property="DefaultFocusAdorner">
       <FocusAdornerTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type AutoCompleteBox}"
                 TargetType="AutoCompleteBox">
     <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Button}"
                 TargetType="Button">
     <Setter Property="Background" Value="{DynamicResource ThemeControlMidBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
 
   <ControlTheme x:Key="SimpleButtonSpinnerRepeatButton"
                 BasedOn="{StaticResource {x:Type RepeatButton}}"

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Calendar}"
                 TargetType="Calendar">
     <!--<Setter Property="Focusable" Value="False" />-->

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type CalendarButton}"
                 TargetType="CalendarButton">
     <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />

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

@@ -7,7 +7,8 @@
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type CalendarDatePicker}"
                 TargetType="CalendarDatePicker">
     <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}" />

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type CalendarDayButton}"
                 TargetType="CalendarDayButton">
     <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}" />

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type CalendarItem}"
                 TargetType="CalendarItem">
     <Setter Property="CornerRadius" Value="1" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type Carousel}" TargetType="Carousel">
     <Setter Property="Template">
       <ControlTemplate>

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type CheckBox}"
                 TargetType="CheckBox">
     <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ComboBox}"
                 TargetType="ComboBox">
     <Setter Property="Background" Value="Transparent" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ComboBoxItem}"
                 TargetType="ComboBoxItem">
     <Setter Property="Background" Value="Transparent" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ContentControl}"
                 TargetType="ContentControl">
     <Setter Property="Template">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ContextMenu}"
                 TargetType="ContextMenu">
     <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type DataValidationErrors}"
                 TargetType="DataValidationErrors">
     <Setter Property="Template">

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

@@ -7,7 +7,8 @@
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-                    xmlns:sys="using:System">
+                    xmlns:sys="using:System"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Height="500"
             Padding="20">

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

@@ -6,7 +6,8 @@
 -->
 
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Width="200"
             Padding="20">

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type DropDownButton}"
                 TargetType="DropDownButton">
     <Setter Property="Background" Value="{DynamicResource ThemeControlMidBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type EmbeddableControlRoot}"
                 TargetType="EmbeddableControlRoot">
     <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Width="350"

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type FlyoutPresenter}"
                 TargetType="FlyoutPresenter">
     <Setter Property="HorizontalContentAlignment" Value="Stretch" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type GridSplitter}"
                 TargetType="GridSplitter">
     <Setter Property="Focusable" Value="True" />

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

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui"
-                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    x:ClassModifier="internal">
   <ControlTheme x:Key="{x:Type ItemsControl}"
                 TargetType="ItemsControl">
     <Setter Property="Template">