Add support for AdwViewSwitcher

Documentation/Reference/README.md

@@ -7,6 +7,7 @@
 -   [MenuItemGroup](protocols/MenuItemGroup.md)
 -   [StateProtocol](protocols/StateProtocol.md)
 -   [View](protocols/View.md)
+-   [ViewSwitcherOption](protocols/ViewSwitcherOption.md)
 -   [Widget](protocols/Widget.md)
 -   [WindowScene](protocols/WindowScene.md)
 -   [WindowSceneGroup](protocols/WindowSceneGroup.md)
@@ -45,6 +46,7 @@
 -   [ToolbarView](structs/ToolbarView.md)
 -   [VStack](structs/VStack.md)
 -   [ViewStack](structs/ViewStack.md)
+-   [ViewSwitcher](structs/ViewSwitcher.md)
 -   [Window](structs/Window.md)
 
 ## Classes

Documentation/Reference/protocols/ViewSwitcherOption.md

@@ -0,0 +1,19 @@
+**PROTOCOL**
+
+# `ViewSwitcherOption`
+
+The protocol an element type for view switcher has to conform to.
+
+## Properties
+### `title`
+
+The title displayed in the switcher and used for identification.
+
+### `icon`
+
+A symbolic representation in the view switcher.
+
+## Methods
+### `init(title:)`
+
+Get the element from the title.

Documentation/Reference/structs/ViewSwitcher.md

@@ -0,0 +1,46 @@
+**STRUCT**
+
+# `ViewSwitcher`
+
+A picker used for indicating multiple views.
+
+It normally controls a `ViewStack` (e.g. via `switch` statements).
+
+## Properties
+### `selection`
+
+The selected element.
+
+### `wide`
+
+Whether the wide style is used, that means the icons and titles are on the same line.
+
+## Methods
+### `init(selection:)`
+
+Initialize a view switcher.
+- Parameter selection: The selected element.
+
+### `container(modifiers:)`
+
+Get a view switcher's view storage.
+- Parameter modifiers: Modify views before being updated.
+- Returns: The view storage.
+
+### `update(_:modifiers:)`
+
+Update a view switcher's view storage.
+- Parameters:
+    - storage: The view storage.
+    - modifiers: Modify views before being updated.
+
+### `updateSwitcher(switcher:)`
+
+Update a view switcher's style and selection.
+- Parameter switcher: The view switcher.
+
+### `wideDesign(_:)`
+
+Set whether to use the wide design.
+- Parameter wide: Whether to use the wide design.
+- Returns: The view switcher.

Sources/Adwaita/View/ViewSwitcher.swift

@@ -0,0 +1,83 @@
+//
+//  ViewSwitcher.swift
+//  Adwaita
+//
+//  Created by david-swift on 03.01.24.
+//
+
+import Libadwaita
+
+/// A picker used for indicating multiple views.
+///
+/// It normally controls a `ViewStack` (e.g. via `switch` statements).
+public struct ViewSwitcher<Element>: Widget where Element: ViewSwitcherOption {
+
+    /// The selected element.
+    @Binding var selection: Element
+    /// Whether the wide style is used, that means the icons and titles are on the same line.
+    var wide = false
+
+    /// Initialize a view switcher.
+    /// - Parameter selection: The selected element.
+    public init(selection: Binding<Element>) {
+        self._selection = selection
+    }
+
+    /// Get a view switcher's view storage.
+    /// - Parameter modifiers: Modify views before being updated.
+    /// - Returns: The view storage.
+    public func container(modifiers: [(View) -> View]) -> ViewStorage {
+        let switcher = Libadwaita.ViewSwitcher()
+        for option in Element.allCases {
+            _ = switcher.addOption(title: option.title, icon: option.icon)
+        }
+        _ = switcher.onSelect {
+            let selection = switcher.getSelection()
+            if let element = Element(title: selection) {
+                self.selection = element
+            }
+        }
+        updateSwitcher(switcher: switcher)
+        return .init(switcher)
+    }
+
+    /// Update a view switcher's view storage.
+    /// - Parameters:
+    ///     - storage: The view storage.
+    ///     - modifiers: Modify views before being updated.
+    public func update(_ storage: ViewStorage, modifiers: [(View) -> View]) {
+        if let switcher = storage.view as? Libadwaita.ViewSwitcher {
+            updateSwitcher(switcher: switcher)
+        }
+    }
+
+    /// Update a view switcher's style and selection.
+    /// - Parameter switcher: The view switcher.
+    func updateSwitcher(switcher: Libadwaita.ViewSwitcher) {
+        _ = switcher.wideDesign(wide)
+        switcher.select(title: selection.title)
+    }
+
+    /// Set whether to use the wide design.
+    /// - Parameter wide: Whether to use the wide design.
+    /// - Returns: The view switcher.
+    public func wideDesign(_ wide: Bool = true) -> Self {
+        var newSelf = self
+        newSelf.wide = wide
+        return newSelf
+    }
+
+}
+
+/// The protocol an element type for view switcher has to conform to.
+public protocol ViewSwitcherOption: CaseIterable {
+
+    /// The title displayed in the switcher and used for identification.
+    var title: String { get }
+    /// A symbolic representation in the view switcher.
+    var icon: Icon { get }
+
+    /// Get the element from the title.
+    init?(title: String)
+
+}

Tests/Demo.swift

@@ -49,6 +49,13 @@ struct Demo: App {
             .closeShortcut()
             .defaultSize(width: 400, height: 250)
             .title("Toolbar Demo")
+            Window(id: "switcher-demo", open: 0) { _ in
+                ViewSwitcherDemo.WindowContent()
+            }
+            .closeShortcut()
+            .defaultSize(width: 600, height: 400)
+            .resizable(false)
+            .title("View Switcher Demo")
         }
 
     }

Tests/Page.swift

@@ -22,6 +22,7 @@ enum Page: String, Identifiable, CaseIterable, Codable {
     case toast
     case list
     case carousel
+    case viewSwitcher
 
     var id: Self {
         self
@@ -31,6 +32,8 @@ enum Page: String, Identifiable, CaseIterable, Codable {
         switch self {
         case .overlayWindow:
             return "Overlay Window"
+        case .viewSwitcher:
+            return "View Switcher"
         default:
             return rawValue.capitalized
         }
@@ -67,9 +70,12 @@ enum Page: String, Identifiable, CaseIterable, Codable {
             return "Organize content in multiple rows."
         case .carousel:
             return "Scroll horizontally on a touchpad or touchscreen, or scroll down on your mouse wheel."
+        case .viewSwitcher:
+            return "Switch the window's view."
         }
     }
 
+    // swiftlint:disable cyclomatic_complexity
     @ViewBuilder
     func view(app: GTUIApp!, window: GTUIApplicationWindow, toast: Signal) -> Body {
         switch self {
@@ -93,8 +99,11 @@ enum Page: String, Identifiable, CaseIterable, Codable {
             ListDemo()
         case .carousel:
             CarouselDemo()
+        case .viewSwitcher:
+            ViewSwitcherDemo(app: app)
         }
     }
+    // swiftlint:enable cyclomatic_complexity
 
 }
 

Tests/ViewSwitcherDemo.swift

@@ -0,0 +1,101 @@
+//
+//  ToolbarDemo.swift
+//  Adwaita
+//
+//  Created by david-swift on 03.01.24.
+//
+
+// swiftlint:disable missing_docs
+
+import Adwaita
+import Libadwaita
+
+struct ViewSwitcherDemo: View {
+
+    var app: GTUIApp
+
+    var view: Body {
+        VStack {
+            Button("View Demo") {
+                app.showWindow("switcher-demo")
+            }
+            .style("suggested-action")
+            .frame(maxSize: 100)
+        }
+    }
+
+    struct WindowContent: View {
+
+        @State private var selection: ViewSwitcherView = .albums
+        @State private var bottom = false
+
+        var view: Body {
+            VStack {
+                Text(selection.title)
+                    .padding()
+                HStack {
+                    Button(bottom ? "Show Top Bar" : "Show Bottom Bar") {
+                        bottom.toggle()
+                    }
+                }
+                .halign(.center)
+            }
+            .valign(.center)
+            .topToolbar {
+                if bottom {
+                    HeaderBar
+                        .empty()
+                } else {
+                    toolbar
+                }
+            }
+            .bottomToolbar(visible: bottom) {
+                toolbar
+            }
+        }
+
+        var toolbar: View {
+            HeaderBar(titleButtons: !bottom) { } end: { }
+                .headerBarTitle {
+                    ViewSwitcher(selection: $selection)
+                        .wideDesign(!bottom)
+                }
+        }
+
+    }
+
+    enum ViewSwitcherView: String, ViewSwitcherOption {
+
+        case albums
+        case artists
+        case songs
+        case playlists
+
+        var title: String {
+            rawValue.capitalized
+        }
+
+        var icon: Icon {
+            .default(icon: {
+                switch self {
+                case .albums:
+                    return .mediaOpticalCdAudio
+                case .artists:
+                    return .avatarDefault
+                case .songs:
+                    return .emblemMusic
+                case .playlists:
+                    return .viewList
+                }
+            }())
+        }
+
+        init?(title: String) {
+            self.init(rawValue: title.lowercased())
+        }
+
+    }
+
+}
+
+// swiftlint:enable missing_docs

user-manual/Information/Widgets.md

@@ -19,6 +19,7 @@ This is an overview of the available widgets and other components in _Adwaita_.
 | StatusPage           | A page with an icon, title, and optionally description and widget.  | AdwStatusPage          |
 | Container            | Supports any widget conforming to `Libadwaita.InsertableContainer`. | Multiple widgets       |
 | Carousel             | A paginated scrolling widget.                                       | AdwCarousel            |
+| ViewSwitcher         | A control for switching between different views.                    | AdwViewSwitcher        |
 | StateWrapper         | A wrapper not affecting the UI which stores state information.      | -                      |
 
 ### View Modifiers
@@ -67,6 +68,11 @@ This is an overview of the available widgets and other components in _Adwaita_.
 | ---------------------------- | --------------------------------------------------------------------------------------- |
 | `trailingSidebar(_:)`        | Whether the sidebar is trailing to the content view.                                    |
 
+### `ViewSwitcher` Modifiers
+| Syntax                       | Description                                                                             |
+| ---------------------------- | --------------------------------------------------------------------------------------- |
+| `wideDesign(_:)`             | Whether the wide view switcher design is used.                                          |
+
 ### Window Types
 | Name                 | Description                                                       | Widget                 |
 | -------------------- | ----------------------------------------------------------------- | ---------------------- |