Add the simple theme

GH-102

Author: TolikPylypchuk

src/KeyboardSwitch.Core/Services/Settings/JsonSettingsService.cs

@@ -120,7 +120,9 @@ private AppSettings CreateDefaultAppSettings() =>
             ShowUninstalledLayoutsMessage = true,
             UseXsel = false,
             AppVersion = this.GetAppVersion(),
-            AppTheme = OperatingSystem.IsMacOS() ? AppTheme.MacOS : AppTheme.Fluent,
+            AppTheme = OperatingSystem.IsMacOS()
+                ? AppTheme.MacOS
+                : OperatingSystem.IsLinux() ? AppTheme.Simple : AppTheme.Fluent,
             AppThemeVariant = AppThemeVariant.Auto
         };
 

src/KeyboardSwitch.Core/Settings/AppSettings.cs

@@ -3,7 +3,8 @@ namespace KeyboardSwitch.Core.Settings;
 public enum AppTheme
 {
     Fluent,
-    MacOS
+    MacOS,
+    Simple
 }
 
 public enum AppThemeVariant

src/KeyboardSwitch.Settings/App.axaml.cs

@@ -3,6 +3,7 @@
 
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Styling;
+using Avalonia.Themes.Simple;
 
 using FluentAvalonia.Styling;
 
@@ -211,6 +212,7 @@ private void SetTheme(AppTheme appTheme)
         this.Styles.Insert(0, appTheme switch
         {
             AppTheme.MacOS => new MacOSTheme(),
+            AppTheme.Simple => new SimpleTheme(),
             _ => new FluentAvaloniaTheme
             {
                 PreferUserAccentColor = true,

src/KeyboardSwitch.Settings/Converters/Convert.cs

@@ -34,13 +34,15 @@ public static string AppThemeToString(AppTheme theme) =>
         {
             AppTheme.Fluent => Messages.AppThemeFluent,
             AppTheme.MacOS => Messages.AppThemeMacOS,
+            AppTheme.Simple => Messages.AppThemeSimple,
             _ => String.Empty
         };
 
     public static AppTheme StringToAppTheme(string theme) =>
         theme switch
         {
             var str when str == Messages.AppThemeMacOS => AppTheme.MacOS,
+            var str when str == Messages.AppThemeSimple => AppTheme.Simple,
             _ => AppTheme.Fluent
         };
 

src/KeyboardSwitch.Settings/KeyboardSwitch.Settings.csproj

@@ -19,6 +19,7 @@
     <PackageReference Include="Avalonia.Desktop" Version="11.3.1" />
     <PackageReference Include="Avalonia.Diagnostics" Version="11.3.1" />
     <PackageReference Include="Avalonia.ReactiveUI" Version="11.3.1" />
+    <PackageReference Include="Avalonia.Themes.Simple" Version="11.3.1" />
     <PackageReference Include="Devolutions.AvaloniaTheme.MacOS" Version="2025.6.12" />
     <PackageReference Include="DynamicData" Version="9.4.1" />
     <PackageReference Include="FluentAvaloniaUI" Version="2.3.0" />

src/KeyboardSwitch.Settings/Properties/Messages.Designer.cs

@@ -132,6 +132,9 @@
   <data name="AppThemeMacOS" xml:space="preserve">
     <value>macOS</value>
   </data>
+  <data name="AppThemeSimple" xml:space="preserve">
+    <value>Simple</value>
+  </data>
   <data name="AppThemeVariant" xml:space="preserve">
     <value>Variant</value>
   </data>

src/KeyboardSwitch.Settings/Properties/Messages.resx

@@ -186,7 +186,7 @@
                     />
                 </Grid>
 
-                <StackPanel Orientation="Horizontal" Margin="10 10 0 0">
+                <StackPanel Orientation="Horizontal" Margin="10 10 0 10">
                     <TextBlock Text="{l:Translate AppTheme}" Classes="Label" />
                     <ComboBox x:Name="AppThemeComboBox" Classes="FormControl" />
 

src/KeyboardSwitch.Settings/Views/PreferencesView.axaml

@@ -182,7 +182,11 @@ public async Task GetAppSettingsDefault()
         Assert.True(settings.ShowUninstalledLayoutsMessage);
         Assert.Equal(Version, settings.AppVersion);
 
-        Assert.Equal(OperatingSystem.IsMacOS() ? AppTheme.MacOS : AppTheme.Fluent, settings.AppTheme);
+        var expectedTheme = OperatingSystem.IsMacOS()
+            ? AppTheme.MacOS
+            : OperatingSystem.IsLinux() ? AppTheme.Simple : AppTheme.Fluent;
+
+        Assert.Equal(expectedTheme, settings.AppTheme);
         Assert.Equal(AppThemeVariant.Auto, settings.AppThemeVariant);
 
         layoutService.Received().GetKeyboardLayouts();