managed chrome compatible with fs.

src/Avalonia.Controls/Chrome/CaptionButtons.cs

@@ -12,18 +12,11 @@ namespace Avalonia.Controls.Chrome
         private CompositeDisposable _disposables;
         private Window _hostWindow;
 
-        public CaptionButtons(Window hostWindow)
-        {
-            _hostWindow = hostWindow;
-        }
-
-        public void Attach()
+        public void Attach(Window hostWindow)
         {
             if (_disposables == null)
             {
-                var layer = ChromeOverlayLayer.GetOverlayLayer(_hostWindow);
-
-                layer.Children.Add(this);
+                _hostWindow = hostWindow;
 
                 _disposables = new CompositeDisposable
                 {
@@ -33,7 +26,6 @@ namespace Avalonia.Controls.Chrome
                         Height = x.Top;
                     }),
 
-
                     _hostWindow.GetObservable(Window.ExtendClientAreaTitleBarHeightHintProperty)
                     .Subscribe(x => InvalidateSize()),
 

src/Avalonia.Controls/Chrome/TitleBar.cs

@@ -0,0 +1,99 @@
+using System;
+using System.Reactive.Disposables;
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
+using Avalonia.Media;
+
+namespace Avalonia.Controls.Chrome
+{
+    public class TitleBar : TemplatedControl
+    {
+        private CompositeDisposable _disposables;
+        private Window _hostWindow;
+        private CaptionButtons _captionButtons;
+
+        public TitleBar(Window hostWindow)
+        {
+            _hostWindow = hostWindow;
+        }
+
+        public TitleBar()
+        {
+
+        }
+
+        protected override Size MeasureOverride(Size availableSize)
+        {
+            return base.MeasureOverride(availableSize);
+        }
+
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            return base.ArrangeOverride(finalSize);
+        }
+
+        public void Attach()
+        {
+            if (_disposables == null)
+            {
+                var layer = ChromeOverlayLayer.GetOverlayLayer(_hostWindow);
+
+                layer.Children.Add(this);
+
+                _disposables = new CompositeDisposable
+                {
+                    _hostWindow.GetObservable(Window.WindowDecorationMarginsProperty)
+                    .Subscribe(x =>
+                    {
+                        Height = x.Top;
+                    }),
+
+                    _hostWindow.GetObservable(Window.ExtendClientAreaTitleBarHeightHintProperty)
+                    .Subscribe(x => InvalidateSize()),
+
+                    _hostWindow.GetObservable(Window.OffScreenMarginProperty)
+                    .Subscribe(x => InvalidateSize()),
+
+                    _hostWindow.GetObservable(Window.WindowStateProperty)
+                    .Subscribe(x =>
+                    {
+                        PseudoClasses.Set(":minimized", x == WindowState.Minimized);
+                        PseudoClasses.Set(":normal", x == WindowState.Normal);
+                        PseudoClasses.Set(":maximized", x == WindowState.Maximized);
+                        PseudoClasses.Set(":fullscreen", x == WindowState.FullScreen);
+                    })
+                };
+            }
+        }
+
+        void InvalidateSize()
+        {
+            Margin = new Thickness(1, _hostWindow.OffScreenMargin.Top, 1, 1);
+            Height = _hostWindow.WindowDecorationMargins.Top;
+        }
+
+        public void Detach()
+        {
+            if (_disposables != null)
+            {
+                var layer = ChromeOverlayLayer.GetOverlayLayer(_hostWindow);
+
+                layer.Children.Remove(this);
+
+                _disposables.Dispose();
+                _disposables = null;
+
+                _captionButtons?.Detach();
+            }
+        }
+
+        protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+        {
+            base.OnApplyTemplate(e);
+
+            _captionButtons = e.NameScope.Find<CaptionButtons>("PART_CaptionButtons");            
+
+            _captionButtons.Attach(_hostWindow);
+        }
+    }
+}

src/Avalonia.Controls/Primitives/ChromeOverlayLayer.cs

@@ -4,7 +4,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Controls.Primitives
 {
-    public class ChromeOverlayLayer : Canvas, ICustomSimpleHitTest
+    public class ChromeOverlayLayer : Panel, ICustomSimpleHitTest
     {
         public Size AvailableSize { get; private set; }
 

src/Avalonia.Controls/Window.cs

@@ -71,7 +71,7 @@ namespace Avalonia.Controls
     public class Window : WindowBase, IStyleable, IFocusScope, ILayoutRoot
     {
         private readonly List<(Window child, bool isDialog)> _children = new List<(Window, bool)>();        
-        private CaptionButtons _managedCaptions;
+        private TitleBar _managedTitleBar;
 
         private bool _isExtendedIntoWindowDecorations;
 
@@ -911,18 +911,18 @@ namespace Avalonia.Controls
         {
             if(hints.HasFlag(ExtendClientAreaChromeHints.ManagedChromeButtons))
             {
-                if(_managedCaptions == null)
+                if(_managedTitleBar == null)
                 {
-                    _managedCaptions = new CaptionButtons(this);
+                    _managedTitleBar = new TitleBar(this);
                 }
 
-                _managedCaptions.Attach();
+                _managedTitleBar.Attach();
             }
             else
             {
-                if(_managedCaptions != null)
+                if(_managedTitleBar != null)
                 {
-                    _managedCaptions.Detach();
+                    _managedTitleBar.Detach();
                 }
             }
         }

src/Avalonia.Themes.Default/CaptionButtons.xaml

@@ -11,9 +11,6 @@
               <Setter Property="Width" Value="45" />
               <Setter Property="Background" Value="Transparent" />
             </Style>
-            <Style Selector="Path">
-              <Setter Property="Fill" Value="White" />
-            </Style>
             <Style Selector="Panel:pointerover">
               <Setter Property="Background" Value="#1FFFFFFF" />
             </Style>
@@ -27,13 +24,13 @@
           </StackPanel.Styles>
           <Panel x:Name="PART_FullScreenButton">
             <Viewbox>
-              <Path Stretch="UniformToFill" />
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" />
             </Viewbox>
           </Panel>
 
           <Panel x:Name="PART_MinimiseButton">
             <Viewbox>
-              <Path Stretch="UniformToFill" Data="M2048 1229v-205h-2048v205h2048z" />
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" Data="M2048 1229v-205h-2048v205h2048z" />
             </Viewbox>
           </Panel>
 
@@ -42,13 +39,13 @@
               <Viewbox.RenderTransform>
                 <RotateTransform Angle="-90" />
               </Viewbox.RenderTransform>
-              <Path Stretch="UniformToFill"/>              
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}"/>              
             </Viewbox>
           </Panel>
 
           <Panel x:Name="PART_CloseButton">
             <Viewbox>
-              <Path Stretch="UniformToFill" Data="M1169 1024l879 -879l-145 -145l-879 879l-879 -879l-145 145l879 879l-879 879l145 145l879 -879l879 879l145 -145z" />
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" Data="M1169 1024l879 -879l-145 -145l-879 879l-879 -879l-145 145l879 879l-879 879l145 145l879 -879l879 879l145 -145z" />
             </Viewbox>
           </Panel>
         </StackPanel>

src/Avalonia.Themes.Default/TitleBar.xaml

@@ -0,0 +1,19 @@
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Design.PreviewWith>
+    <Border>
+      <TitleBar Background="SkyBlue" Height="30" Width="300" Foreground="Black" />
+    </Border>
+  </Design.PreviewWith>
+  <Style Selector="TitleBar">
+    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>    
+    <Setter Property="MaxHeight" Value="30" />
+    <Setter Property="Background" Value="Red" />
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border Background="{TemplateBinding Background}" HorizontalAlignment="Stretch">
+          <CaptionButtons Name="PART_CaptionButtons" HorizontalAlignment="Right" Foreground="{TemplateBinding Foreground}" />
+        </Border>
+      </ControlTemplate>
+    </Setter>
+  </Style>
+</Styles>

src/Avalonia.Themes.Fluent/CaptionButtons.xaml

@@ -0,0 +1,67 @@
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Style Selector="CaptionButtons">
+    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
+    <Setter Property="Canvas.Right" Value="0" />
+    <Setter Property="MaxHeight" Value="30" />
+    <Setter Property="Template">
+      <ControlTemplate>
+        <StackPanel Spacing="2" Margin="0 0 7 0" VerticalAlignment="Stretch" TextBlock.FontSize="10" Orientation="Horizontal">
+          <StackPanel.Styles>
+            <Style Selector="Panel">
+              <Setter Property="Width" Value="45" />
+              <Setter Property="Background" Value="Transparent" />
+            </Style>
+            <Style Selector="Panel:pointerover">
+              <Setter Property="Background" Value="#CFFFFFFF" />
+            </Style>
+            <Style Selector="Panel#PART_CloseButton:pointerover">
+              <Setter Property="Background" Value="#AFFF0000" />
+            </Style>
+            <Style Selector="Viewbox">
+              <Setter Property="Width" Value="11" />
+              <Setter Property="Margin" Value="2" />
+            </Style>
+          </StackPanel.Styles>
+          <Panel x:Name="PART_FullScreenButton">
+            <Viewbox>
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" />
+            </Viewbox>
+          </Panel>
+
+          <Panel x:Name="PART_MinimiseButton">
+            <Viewbox>
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" Data="M2048 1229v-205h-2048v205h2048z" />
+            </Viewbox>
+          </Panel>
+
+          <Panel x:Name="PART_RestoreButton">
+            <Viewbox>
+              <Viewbox.RenderTransform>
+                <RotateTransform Angle="-90" />
+              </Viewbox.RenderTransform>
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}"/>
+            </Viewbox>
+          </Panel>
+
+          <Panel x:Name="PART_CloseButton">
+            <Viewbox>
+              <Path Stretch="UniformToFill" Fill="{TemplateBinding Foreground}" Data="M1169 1024l879 -879l-145 -145l-879 879l-879 -879l-145 145l879 879l-879 879l145 145l879 -879l879 879l145 -145z" />
+            </Viewbox>
+          </Panel>
+        </StackPanel>
+      </ControlTemplate>
+    </Setter>
+  </Style>
+  <Style Selector="CaptionButtons Panel#PART_RestoreButton Path">
+    <Setter Property="Data" Value="M2048 2048v-2048h-2048v2048h2048zM1843 1843h-1638v-1638h1638v1638z" />
+  </Style>
+  <Style Selector="CaptionButtons:maximized Panel#PART_RestoreButton Path">
+    <Setter Property="Data" Value="M2048 410h-410v-410h-1638v1638h410v410h1638v-1638zM1434 1434h-1229v-1229h1229v1229zM1843 1843h-1229v-205h1024v-1024h205v1229z" />
+  </Style>
+  <Style Selector="CaptionButtons Panel#PART_FullScreenButton Path">
+    <Setter Property="Data" Value="M2048 2048v-819h-205v469l-1493 -1493h469v-205h-819v819h205v-469l1493 1493h-469v205h819z" />
+  </Style>
+  <Style Selector="CaptionButtons:fullscreen Panel#PART_FullScreenButton Path">
+    <Setter Property="Data" Value="M205 1024h819v-819h-205v469l-674 -674l-145 145l674 674h-469v205zM1374 1229h469v-205h-819v819h205v-469l674 674l145 -145z" />
+  </Style>
+ Styles>

src/Avalonia.Themes.Fluent/FluentTheme.xaml

@@ -7,7 +7,8 @@
 
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.FocusAdorner.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Button.xaml?assembly=Avalonia.Themes.Fluent"/>
-  <StyleInclude Source="resm:Avalonia.Themes.Fluent.Carousel.xaml?assembly=Avalonia.Themes.Fluent"/>
+  <StyleInclude Source="resm:Avalonia.Themes.Fluent.CaptionButtons.xaml?assembly=Avalonia.Themes.Fluent"/>
+  <StyleInclude Source="resm:Avalonia.Themes.Fluent.Carousel.xaml?assembly=Avalonia.Themes.Fluent"/>  
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.CheckBox.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.ComboBox.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.ComboBoxItem.xaml?assembly=Avalonia.Themes.Fluent"/>
@@ -36,6 +37,7 @@
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.TextBox.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.ToggleButton.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.Expander.xaml?assembly=Avalonia.Themes.Fluent"/>
+  <StyleInclude Source="resm:Avalonia.Themes.Fluent.TitleBar.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.TreeView.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.TreeViewItem.xaml?assembly=Avalonia.Themes.Fluent"/>
   <StyleInclude Source="resm:Avalonia.Themes.Fluent.UserControl.xaml?assembly=Avalonia.Themes.Fluent"/>

src/Avalonia.Themes.Fluent/TitleBar.xaml

@@ -0,0 +1,68 @@
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Design.PreviewWith>
+    <Border>
+      <TitleBar Background="SkyBlue" Height="30" Width="300" Foreground="Black" />
+    </Border>
+  </Design.PreviewWith>
+  <Style Selector="TitleBar">
+    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
+    <Setter Property="Background" Value="Red" />
+    <Setter Property="VerticalAlignment" Value="Top" />
+    <Setter Property="HorizontalAlignment" Value="Stretch" />
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Panel HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="Stretch">
+          <Panel x:Name="PART_MouseTracker" Height="15" VerticalAlignment="Top" />
+          <Panel x:Name="PART_Container">
+            <Border x:Name="PART_Background" Background="{TemplateBinding Background}" />
+            <CaptionButtons x:Name="PART_CaptionButtons" VerticalAlignment="Top" HorizontalAlignment="Right" Foreground="{TemplateBinding Foreground}" />
+          </Panel>
+        </Panel>
+      </ControlTemplate>
+    </Setter>
+  </Style>
+
+  <Style Selector="TitleBar /template/ Border#PART_Background">
+    <Setter Property="IsHitTestVisible" Value="False" />
+  </Style>
+
+  <Style Selector="TitleBar:fullscreen /template/ Border#PART_Background">
+    <Setter Property="IsHitTestVisible" Value="True" />
+  </Style>
+  
+  
+
+  <Style Selector="TitleBar:fullscreen /template/ Panel#PART_MouseTracker">
+    <Setter Property="Background" Value="Transparent" />
+  </Style>
+
+  <Style Selector="TitleBar:fullscreen:not(:pointerover) /template/ Panel#PART_Container">
+    <Style.Animations>
+      <Animation Duration="0:0:.5" Easing="SineEaseInOut">
+        <KeyFrame Cue="0%">
+          <Setter Property="TranslateTransform.Y" Value="0"/>
+        </KeyFrame>
+        <KeyFrame Cue="100%">
+          <Setter Property="TranslateTransform.Y" Value="-30"/>
+        </KeyFrame>
+      </Animation>
+    </Style.Animations>
+    <Setter Property="TranslateTransform.Y" Value="-30" />
+  </Style>
+
+  <Style Selector="TitleBar:fullscreen:pointerover /template/ Panel#PART_Container">
+    <Style.Animations>
+      <Animation Duration="0:0:.5" Easing="SineEaseInOut">
+        <KeyFrame Cue="0%">          
+          <Setter Property="TranslateTransform.Y" Value="-30"/>          
+        </KeyFrame>
+        <KeyFrame Cue="100%">
+          <Setter Property="TranslateTransform.Y" Value="0"/>
+        </KeyFrame>
+      </Animation>
+    </Style.Animations>    
+  </Style>
+
+  
+  
+</Styles>

src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs

@@ -90,6 +90,10 @@ namespace Avalonia.Win32
                 case WindowsMessage.WM_NCHITTEST:
                     if (lRet == IntPtr.Zero)
                     {
+                        if(WindowState == WindowState.FullScreen)
+                        {
+                            return (IntPtr)HitTestValues.HTCLIENT;
+                        }
                         var hittestResult = HitTestNCA(hWnd, wParam, lParam);
 
                         lRet = (IntPtr)hittestResult;

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -181,6 +181,11 @@ namespace Avalonia.Win32
         {
             get
             {
+                if(_isFullScreenActive)
+                {
+                    return WindowState.FullScreen;
+                }
+
                 var placement = default(WINDOWPLACEMENT);
                 GetWindowPlacement(_hwnd, ref placement);