Add option to set preferred color scheme

Sources/SettingsKit/Components/SettingsKitScene.swift

@@ -22,6 +22,8 @@ struct SettingsKitScene<Content>: Scene where Content: Scene {
     var symbolVariant: SymbolVariants
     /// The design of the settings window.
     var design: SettingsWindowDesign
+    /// The preferred color scheme.
+    var colorScheme: ColorScheme?
     /// The filter in the sidebar design.
     @State private var search = ""
     /// The binding controlling the selection.
@@ -51,6 +53,7 @@ struct SettingsKitScene<Content>: Scene where Content: Scene {
                 .onChange(of: model.selectedTab) { newValue in
                     selectedTab?.wrappedValue = newValue
                 }
+                .preferredColorScheme(colorScheme)
             }
         }
     }

Sources/SettingsKit/Model/Extensions/SwiftUI/Scene.swift

@@ -14,6 +14,7 @@ extension Scene {
     /// - Parameters:
     ///   - design: Whether the default or sidebar design is used.
     ///   - symbolVariant: The way symbols should be displayed.
+    ///   - preferredColorScheme: Force either light or dark mode.
     ///   - selectedTab: The currently selected tab.
     ///   - settings: The settings tabs in the settings window.
     /// - Returns: The scene with the settings.
@@ -32,6 +33,7 @@ extension Scene {
     public func settings(
         design: SettingsWindowDesign = .default,
         symbolVariant: SymbolVariants = .none,
+        preferredColorScheme: ColorScheme? = nil,
         selectedTab: Binding<String>? = nil,
         @ArrayBuilder<SettingsTab> _ settings: () -> [SettingsTab]
     ) -> some Scene {
@@ -42,6 +44,7 @@ extension Scene {
             standardID: standardID,
             symbolVariant: symbolVariant,
             design: design,
+            colorScheme: preferredColorScheme,
             selectedTab: selectedTab
         )
     }

Tests/TestApp/TestApp/TestAppApp.swift

@@ -21,6 +21,9 @@ struct TestAppApp: App {
     /// The currently selected tab.
     @AppStorage("tab")
     var selectedTab = ""
+    /// The preferred color scheme.
+    @AppStorage("scheme")
+    var forceDark = false
 
     /// The main view of the test app.
     var body: some Scene {
@@ -30,16 +33,23 @@ struct TestAppApp: App {
                 selectedTab = "test"
             }
         }
-        .settings(design: sidebarDesign ? .sidebar : .default, selectedTab: $selectedTab) {
+        .settings(
+                design: sidebarDesign ? .sidebar : .default,
+                preferredColorScheme: forceDark ? .dark : nil,
+                selectedTab: $selectedTab
+        ) {
             for settingsTab in appModel.allSettings {
                 settingsTab
             }
             SettingsTab(.new(title: "Test", icon: .arrowLeftCircle), id: "test") {
                 SettingsSubtab(.noSelection, id: "subtab") {
                     let width = 500.0
                     let height = 100.0
-                    Toggle("Sidebar Design", isOn: $sidebarDesign)
-                        .frame(width: width, height: height)
+                    Form {
+                        Toggle("Sidebar Design", isOn: $sidebarDesign)
+                        Toggle("Force Dark Design", isOn: $forceDark)
+                    }
+                    .frame(width: width, height: height)
                 }
             }
             .frame()