UI - Add a monochrome tray icon option

- New "Monochrome tray icon" toggle under General settings
- Shows a black or white icon matching the light or dark mode of the system tray
- On Windows the color follows the taskbar (Windows mode), which can differ from the app mode
- On Linux the color follows the system's light or dark mode
- On macOS the icon is a template icon, so the menu bar colors it itself
- Icons come in 16 to 256px, including the sizes used for high-DPI tray scaling

Based on the idea and work in #867 by ArthurGamerHD.

src/Artemis.UI.Linux/App.axaml

@@ -14,7 +14,7 @@
 
     <TrayIcon.Icons>
         <TrayIcons>
-            <TrayIcon Icon="avares://Artemis.UI/Assets/Images/Logo/application.ico" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
+            <TrayIcon Icon="{CompiledBinding TrayIcon}" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
                 <TrayIcon.Menu>
                     <NativeMenu>
                         <NativeMenuItem Header="Home" Command="{CompiledBinding OpenScreen}" CommandParameter="home" />

src/Artemis.UI.MacOS/App.axaml

@@ -14,7 +14,7 @@
 
     <TrayIcon.Icons>
         <TrayIcons>
-            <TrayIcon Icon="avares://Artemis.UI/Assets/Images/Logo/application.ico" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
+            <TrayIcon Icon="{CompiledBinding TrayIcon}" MacOSProperties.IsTemplateIcon="{CompiledBinding MonochromeTrayIcon}" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
                 <TrayIcon.Menu>
                     <NativeMenu>
                         <NativeMenuItem Header="Home" Command="{CompiledBinding OpenScreen}" CommandParameter="home" />

src/Artemis.UI.Windows/App.axaml

@@ -14,7 +14,7 @@
 
     <TrayIcon.Icons>
         <TrayIcons>
-            <TrayIcon Icon="avares://Artemis.UI/Assets/Images/Logo/application.ico" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
+            <TrayIcon Icon="{CompiledBinding TrayIcon}" ToolTipText="Artemis" Command="{CompiledBinding OpenScreen}">
                 <TrayIcon.Menu>
                     <NativeMenu>
                         <NativeMenuItem Header="Home" Command="{CompiledBinding OpenScreen}" CommandParameter="home" />

src/Artemis.UI.Windows/DryIoc/ContainerExtensions.cs

@@ -1,5 +1,6 @@
 using Artemis.Core.Providers;
 using Artemis.Core.Services;
+using Artemis.UI.Services.Tray;
 using Artemis.UI.Services.Updating;
 using Artemis.UI.Shared.Providers;
 using Artemis.UI.Windows.Providers;
@@ -25,5 +26,6 @@ public static class UIContainerExtensions
         container.Register<InputProvider, WindowsInputProvider>(serviceKey: WindowsInputProvider.Id);
         container.Register<IUpdateNotificationProvider, WindowsUpdateNotificationProvider>();
         container.Register<IProtocolProvider, ProtocolProvider>();
+        container.Register<ITrayThemeProvider, WindowsTrayThemeProvider>(Reuse.Singleton);
     }
 }

src/Artemis.UI.Windows/Providers/WindowsTrayThemeProvider.cs

@@ -0,0 +1,49 @@
+using System;
+using Artemis.UI.Services.Tray;
+using Microsoft.Win32;
+using Serilog;
+
+namespace Artemis.UI.Windows.Providers;
+
+/// <summary>
+///     Provides the light or dark mode of the Windows taskbar, which can differ from the app mode Avalonia reports.
+/// </summary>
+public class WindowsTrayThemeProvider : ITrayThemeProvider
+{
+    private const string PersonalizeKey = @"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize";
+
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="WindowsTrayThemeProvider" /> class.
+    /// </summary>
+    public WindowsTrayThemeProvider(ILogger logger)
+    {
+        try
+        {
+            SystemEvents.UserPreferenceChanged += SystemEventsOnUserPreferenceChanged;
+        }
+        catch (Exception e)
+        {
+            logger.Warning(e, "Could not subscribe to system events, the tray icon won't follow changes to the taskbar color");
+        }
+    }
+
+    /// <inheritdoc />
+    public bool IsTrayDark
+    {
+        get
+        {
+            // Versions of Windows without the setting only have a dark taskbar
+            using RegistryKey? key = Registry.CurrentUser.OpenSubKey(PersonalizeKey);
+            return key?.GetValue("SystemUsesLightTheme") is not 1;
+        }
+    }
+
+    /// <inheritdoc />
+    public event EventHandler? TrayThemeChanged;
+
+    private void SystemEventsOnUserPreferenceChanged(object sender, UserPreferenceChangedEventArgs e)
+    {
+        if (e.Category == UserPreferenceCategory.General)
+            TrayThemeChanged?.Invoke(this, EventArgs.Empty);
+    }
+}

src/Artemis.UI/DryIoc/ContainerExtensions.cs

@@ -4,6 +4,7 @@ using Artemis.UI.DryIoc.InstanceProviders;
 using Artemis.UI.Screens.Device.Layout.LayoutProviders;
 using Artemis.UI.Screens.VisualScripting;
 using Artemis.UI.Services.Interfaces;
+using Artemis.UI.Services.Tray;
 using Artemis.UI.Services.Updating;
 using Artemis.UI.Shared;
 using Artemis.UI.Shared.Services.NodeEditor;
@@ -33,6 +34,7 @@ public static class ContainerExtensions
         container.Register<NodeScriptWindowViewModelBase, NodeScriptWindowViewModel>(Reuse.Singleton);
         container.Register<IPropertyVmFactory, PropertyVmFactory>(Reuse.Singleton);
         container.Register<IUpdateNotificationProvider, BasicUpdateNotificationProvider>();
+        container.Register<ITrayThemeProvider, BasicTrayThemeProvider>(Reuse.Singleton);
         
         container.RegisterMany(thisAssembly, type => type.IsAssignableTo<IArtemisUIService>(), Reuse.Singleton);
     }

src/Artemis.UI/Screens/Root/RootViewModel.cs

@@ -7,6 +7,7 @@ using Artemis.Core.Services;
 using Artemis.UI.Models;
 using Artemis.UI.Screens.Sidebar;
 using Artemis.UI.Services.Interfaces;
+using Artemis.UI.Services.Tray;
 using Artemis.UI.Services.Updating;
 using Artemis.UI.Shared;
 using Artemis.UI.Shared.Routing;
@@ -16,6 +17,7 @@ using Artemis.WebClient.Workshop.Services;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Platform;
 using Avalonia.Threading;
 using ReactiveUI;
 using Serilog;
@@ -34,6 +36,11 @@ public class RootViewModel : RoutableHostScreen<RoutableScreen>, IMainWindowProv
     private readonly IUpdateService _updateService;
     private readonly IWindowService _windowService;
     private readonly ObservableAsPropertyHelper<ViewModelBase?> _titleBarViewModel;
+    private readonly PluginSetting<bool> _monochromeTrayIcon;
+    private readonly ITrayThemeProvider _trayThemeProvider;
+    private WindowIcon? _coloredTrayIcon;
+    private WindowIcon? _blackTrayIcon;
+    private WindowIcon? _whiteTrayIcon;
 
     public RootViewModel(ILogger logger,
         IRouter router,
@@ -45,6 +52,7 @@ public class RootViewModel : RoutableHostScreen<RoutableScreen>, IMainWindowProv
         IDebugService debugService,
         IUpdateService updateService,
         IWorkshopService workshopService,
+        ITrayThemeProvider trayThemeProvider,
         SidebarViewModel sidebarViewModel,
         DefaultTitleBarViewModel defaultTitleBarViewModel)
     {
@@ -60,8 +68,17 @@ public class RootViewModel : RoutableHostScreen<RoutableScreen>, IMainWindowProv
         _debugService = debugService;
         _updateService = updateService;
         _defaultTitleBarViewModel = defaultTitleBarViewModel;
+        _trayThemeProvider = trayThemeProvider;
         _lifeTime = (IClassicDesktopStyleApplicationLifetime) Application.Current!.ApplicationLifetime!;
 
+        _monochromeTrayIcon = settingsService.GetSetting("UI.MonochromeTrayIcon", false);
+        _monochromeTrayIcon.SettingChanged += (_, _) =>
+        {
+            this.RaisePropertyChanged(nameof(MonochromeTrayIcon));
+            this.RaisePropertyChanged(nameof(TrayIcon));
+        };
+        _trayThemeProvider.TrayThemeChanged += (_, _) => Dispatcher.UIThread.Post(() => this.RaisePropertyChanged(nameof(TrayIcon)));
+
         router.SetRoot(this);
         mainWindowService.ConfigureMainWindowProvider(this);
         
@@ -117,6 +134,26 @@ public class RootViewModel : RoutableHostScreen<RoutableScreen>, IMainWindowProv
     public ReactiveCommand<Unit, Unit> Exit { get; }
 
     public ViewModelBase? TitleBarViewModel => _titleBarViewModel.Value;
+
+    /// <summary>
+    ///     Gets a value indicating whether the tray icon is black or white rather than colored.
+    /// </summary>
+    public bool MonochromeTrayIcon => _monochromeTrayIcon.Value;
+
+    /// <summary>
+    ///     Gets the tray icon, in black or white to match the system tray when <see cref="MonochromeTrayIcon" /> is enabled.
+    /// </summary>
+    public WindowIcon TrayIcon
+    {
+        get
+        {
+            if (!_monochromeTrayIcon.Value)
+                return _coloredTrayIcon ??= LoadTrayIcon("application");
+            return _trayThemeProvider.IsTrayDark
+                ? _whiteTrayIcon ??= LoadTrayIcon("application-monochrome-white")
+                : _blackTrayIcon ??= LoadTrayIcon("application-monochrome-black");
+        }
+    }
     public static PluginSetting<WindowSize?>? WindowSizeSetting { get; private set; }
 
     public void GoBack()
@@ -188,6 +225,11 @@ public class RootViewModel : RoutableHostScreen<RoutableScreen>, IMainWindowProv
 
     #region Implementation of IMainWindowProvider
 
+    private static WindowIcon LoadTrayIcon(string name)
+    {
+        return new WindowIcon(AssetLoader.Open(new Uri($"avares://Artemis.UI/Assets/Images/Logo/{name}.ico")));
+    }
+
     /// <inheritdoc />
     public bool IsMainWindowOpen => _lifeTime.MainWindow != null;
 

src/Artemis.UI/Screens/Settings/Tabs/GeneralTabView.axaml

@@ -71,6 +71,19 @@
                         </Grid>
                         <Border Classes="card-separator" IsVisible="{CompiledBinding IsWindows11}"/>
 
+                        <Grid RowDefinitions="*,*" ColumnDefinitions="*,Auto">
+                            <StackPanel Grid.Column="0">
+                                <TextBlock>Monochrome tray icon</TextBlock>
+                                <TextBlock Classes="subtitle" TextWrapping="Wrap">
+                                    Show a black or white icon in the system tray instead of the colored one, matching your light or dark mode.
+                                </TextBlock>
+                            </StackPanel>
+                            <StackPanel Grid.Row="0" Grid.Column="1" VerticalAlignment="Center">
+                                <ToggleSwitch IsChecked="{CompiledBinding UIMonochromeTrayIcon.Value}" OnContent="Yes" OffContent="No" MinWidth="0" Margin="0 -10" />
+                            </StackPanel>
+                        </Grid>
+                        <Border Classes="card-separator" />
+                        
                         <Grid RowDefinitions="*,*" ColumnDefinitions="*,Auto">
                             <StackPanel Grid.Column="0">
                                 <TextBlock>Startup delay</TextBlock>

src/Artemis.UI/Screens/Settings/Tabs/GeneralTabViewModel.cs

@@ -159,6 +159,7 @@ public class GeneralTabViewModel : RoutableScreen
     public PluginSetting<int> UIAutoRunDelay => _settingsService.GetSetting("UI.AutoRunDelay", 15);
     public PluginSetting<bool> UIShowOnStartup => _settingsService.GetSetting("UI.ShowOnStartup", true);
     public PluginSetting<bool> EnableMica => _settingsService.GetSetting("UI.EnableMica", true);
+    public PluginSetting<bool> UIMonochromeTrayIcon => _settingsService.GetSetting("UI.MonochromeTrayIcon", false);
     public PluginSetting<bool> UICheckForUpdates => _settingsService.GetSetting("UI.Updating.AutoCheck", true);
     public PluginSetting<bool> WorkshopShowNotifications => _settingsService.GetSetting("Workshop.ShowNotifications", true);
     public PluginSetting<bool> UIAutoUpdate => _settingsService.GetSetting("UI.Updating.AutoInstall", true);

src/Artemis.UI/Services/Tray/BasicTrayThemeProvider.cs

@@ -0,0 +1,26 @@
+using System;
+using Avalonia;
+using Avalonia.Platform;
+
+namespace Artemis.UI.Services.Tray;
+
+/// <summary>
+///     Provides the light or dark mode of the system tray based on the light or dark mode of the operating system.
+/// </summary>
+public class BasicTrayThemeProvider : ITrayThemeProvider
+{
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="BasicTrayThemeProvider" /> class.
+    /// </summary>
+    public BasicTrayThemeProvider()
+    {
+        if (Application.Current?.PlatformSettings is { } platformSettings)
+            platformSettings.ColorValuesChanged += (_, _) => TrayThemeChanged?.Invoke(this, EventArgs.Empty);
+    }
+
+    /// <inheritdoc />
+    public bool IsTrayDark => Application.Current?.PlatformSettings?.GetColorValues().ThemeVariant != PlatformThemeVariant.Light;
+
+    /// <inheritdoc />
+    public event EventHandler? TrayThemeChanged;
+}

src/Artemis.UI/Services/Tray/ITrayThemeProvider.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace Artemis.UI.Services.Tray;
+
+/// <summary>
+///     Provides the light or dark mode of the system tray.
+/// </summary>
+public interface ITrayThemeProvider
+{
+    /// <summary>
+    ///     Gets a value indicating whether the system tray has a dark background.
+    /// </summary>
+    bool IsTrayDark { get; }
+
+    /// <summary>
+    ///     Occurs when the background of the system tray may have changed, possibly on a background thread.
+    /// </summary>
+    event EventHandler? TrayThemeChanged;
+}