wip

samples/ControlCatalog/App.xaml.cs

@@ -5,6 +5,7 @@ using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Markup.Xaml.Styling;
 using Avalonia.Styling;
+using Avalonia.Themes.Default;
 using Avalonia.Themes.Fluent;
 using ControlCatalog.ViewModels;
 
@@ -29,6 +30,8 @@ namespace ControlCatalog
 
         public static FluentTheme Fluent = new FluentTheme(new Uri("avares://ControlCatalog/Styles"));
 
+        public static SimpleTheme Default = new SimpleTheme(new Uri("avares://ControlCatalog/Styles"));
+
         public static Styles DefaultLight = new Styles
         {
             new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
@@ -43,14 +46,7 @@ namespace ControlCatalog
             {
                 Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/BaseLight.xaml")
             },
-            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("avares://Avalonia.Themes.Default/Accents/BaseLight.xaml")
-            },
-            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("avares://Avalonia.Themes.Default/DefaultTheme.xaml")
-            }
+            Default
         };
 
         public static Styles DefaultDark = new Styles
@@ -67,14 +63,7 @@ namespace ControlCatalog
             {
                 Source = new Uri("avares://Avalonia.Themes.Fluent/Accents/BaseDark.xaml")
             },
-            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("avares://Avalonia.Themes.Default/Accents/BaseDark.xaml")
-            },
-            new StyleInclude(new Uri("resm:Styles?assembly=ControlCatalog"))
-            {
-                Source = new Uri("avares://Avalonia.Themes.Default/DefaultTheme.xaml")
-            }
+            Default
         };
 
         public override void Initialize()

samples/ControlCatalog/MainView.xaml.cs

@@ -63,11 +63,13 @@ namespace ControlCatalog
                     }
                     else if (theme == CatalogTheme.DefaultLight)
                     {
+                        App.Default.Mode = Avalonia.Themes.Default.SimpleThemeMode.Light;
                         Application.Current.Styles[0] = App.DefaultLight;
                         Application.Current.Styles[1] = App.DataGridDefault;
                     }
                     else if (theme == CatalogTheme.DefaultDark)
                     {
+                        App.Default.Mode = Avalonia.Themes.Default.SimpleThemeMode.Dark;
                         Application.Current.Styles[0] = App.DefaultDark;
                         Application.Current.Styles[1] = App.DataGridDefault;
                     }

src/Avalonia.Themes.Default/SimpleTheme.cs

@@ -14,6 +14,7 @@ namespace Avalonia.Themes.Default
         private bool _isLoading;
         private Styles _simpleDark = new();
         private Styles _simpleLight = new();
+        private Styles _sharedStyles = new();
         private IStyle? _loaded;
 
         /// <summary>
@@ -32,7 +33,12 @@ namespace Avalonia.Themes.Default
         /// <param name="serviceProvider">The XAML service provider.</param>
         public SimpleTheme(IServiceProvider serviceProvider)
         {
-            _baseUri = ((IUriContext)serviceProvider.GetService(typeof(IUriContext))).BaseUri;
+            var service = serviceProvider.GetService(typeof(IUriContext));
+            if (service == null)
+            {
+                throw new Exception("There is no service object of type IUriContext!");
+            }
+            _baseUri = ((IUriContext)service).BaseUri;
             InitStyles(_baseUri);
         }
 
@@ -46,6 +52,22 @@ namespace Avalonia.Themes.Default
             get => GetValue(ModeProperty);
             set => SetValue(ModeProperty, value);
         }
+        protected override void OnPropertyChanged<T>(AvaloniaPropertyChangedEventArgs<T> change)
+        {
+            base.OnPropertyChanged(change);
+            if (change.Property == ModeProperty)
+            {
+                if (Mode == SimpleThemeMode.Dark)
+                {
+                    (Loaded as Styles)![1] = _simpleDark[0];
+                }
+                else
+                {
+                    (Loaded as Styles)![1] = _simpleLight[0];
+                }
+            }
+        }
+
         public IStyle Loaded
         {
             get
@@ -56,11 +78,11 @@ namespace Avalonia.Themes.Default
 
                     if (Mode == SimpleThemeMode.Light)
                     {
-                        _loaded = _simpleLight;
+                        _loaded = new Styles { _sharedStyles , _simpleLight};
                     }
                     else if (Mode == SimpleThemeMode.Dark)
                     {
-                        _loaded = _simpleDark;
+                        _loaded = new Styles { _sharedStyles, _simpleDark };
                     }
                     _isLoading = false;
                 }
@@ -110,16 +132,18 @@ namespace Avalonia.Themes.Default
         void IResourceProvider.RemoveOwner(IResourceHost owner) => (Loaded as IResourceProvider)?.RemoveOwner(owner);
         private void InitStyles(Uri baseUri)
         {
-
-            _simpleLight = new Styles
+            _sharedStyles = new Styles
             {
                 new StyleInclude(baseUri)
                 {
-                    Source = new Uri("avares://Avalonia.Themes.Default/Accents/BaseLight.xaml")
-                },
+                    Source = new Uri("avares://Avalonia.Themes.Default/DefaultTheme.xaml")
+                }
+            };
+            _simpleLight = new Styles
+            {
                 new StyleInclude(baseUri)
                 {
-                    Source = new Uri("avares://Avalonia.Themes.Default/DefaultTheme.xaml")
+                    Source = new Uri("avares://Avalonia.Themes.Default/Accents/BaseLight.xaml")
                 }
             };
 
@@ -128,10 +152,6 @@ namespace Avalonia.Themes.Default
                 new StyleInclude(baseUri)
                 {
                     Source = new Uri("avares://Avalonia.Themes.Default/Accents/BaseDark.xaml")
-                },
-                new StyleInclude(baseUri)
-                {
-                    Source = new Uri("avares://Avalonia.Themes.Default/DefaultTheme.xaml")
                 }
             };
         }