ui: use custom window chrome on Windows

Author: mjcheetham

src/shared/Core/UI/Controls/DialogWindow.axaml

@@ -15,13 +15,6 @@
         ShowInTaskbar="True" ShowActivated="True"
         PointerPressed="Window_PointerPressed"
         KeyUp="Window_KeyUp">
-<!--
-    BUG: We cannot use the ExtendClientArea* properties on Windows because the platform implementation
-         incorrectly sets the size of the window and we end up with a very wide window:
-            https://github.com/AvaloniaUI/Avalonia/issues/5632
-
-         This is less of an issue because we're still using the WPF-based UI on Windows.
--->
     <Design.DataContext>
         <vm:WindowViewModel/>
     </Design.DataContext>
@@ -66,8 +59,8 @@
                 <TextBlock Text="DEBUG:" Margin="5,0" Foreground="#888888" VerticalAlignment="Center"/>
                 <CheckBox IsChecked="{Binding ExtendClientArea}"
                           Content="Extend Client Area" Margin="5,0"/>
-                <CheckBox IsChecked="{Binding ShowClientChromeOverride}"
-                          Content="Show Client Chrome" Margin="5,0"/>
+                <CheckBox IsChecked="{Binding ShowCustomChromeOverride}"
+                          Content="Show Custom Chrome" Margin="5,0"/>
             </StackPanel>
 
             <ContentControl x:Name="contentHolder" Margin="30,25,30,30"/>

src/shared/Core/UI/ViewModels/WindowViewModel.cs

@@ -5,7 +5,7 @@ namespace GitCredentialManager.UI.ViewModels
     public class WindowViewModel : ViewModel
     {
         private bool _extendClientArea;
-        private bool _showClientChromeOverride;
+        private bool _showCustomChromeOverride;
         private bool _showDebugControls;
         private string _title;
 
@@ -16,8 +16,8 @@ public WindowViewModel()
         {
             Title = Constants.DefaultWindowTitle;
 
-            // Default to hiding the system chrome on macOS only for now
-            ExtendClientArea = PlatformUtils.IsMacOS();
+            // Extend the client area on Windows and macOS only
+            ExtendClientArea = PlatformUtils.IsMacOS() || PlatformUtils.IsWindows();
         }
 
         public bool WindowResult { get; private set; }
@@ -30,15 +30,17 @@ public bool ShowDebugControls
 
         public bool ShowCustomChrome
         {
-            get => ShowClientChromeOverride || (ExtendClientArea && !PlatformUtils.IsMacOS());
+            // On macOS we typically do NOT want to show the custom chrome if we've extended the client area
+            // because the native 'traffic light' controls will still be visible and we don't want to show our own.
+            get => ShowCustomChromeOverride || (ExtendClientArea && !PlatformUtils.IsMacOS());
         }
 
-        public bool ShowClientChromeOverride
+        public bool ShowCustomChromeOverride
         {
-            get => _showClientChromeOverride;
+            get => _showCustomChromeOverride;
             set
             {
-                SetAndRaisePropertyChanged(ref _showClientChromeOverride, value);
+                SetAndRaisePropertyChanged(ref _showCustomChromeOverride, value);
                 RaisePropertyChanged(nameof(ShowCustomChrome));
             }
         }