Add visionOS support (#203)

Author: bbrk24

.github/workflows/build-test-and-docs.yml

@@ -65,6 +65,7 @@ jobs:
           - iPhone
           - iPad
           - TV
+          - Vision
     steps:
     - name: Force Xcode 15.4
       run: sudo xcode-select -switch /Applications/Xcode_15.4.app

Examples/Sources/ControlsExample/ControlsApp.swift

@@ -30,13 +30,15 @@ struct ControlsApp: App {
                     }
                     .padding(.bottom, 20)
 
-                    VStack {
-                        Text("Toggle button")
-                        Toggle("Toggle me!", active: $exampleButtonState)
-                            .toggleStyle(.button)
-                        Text("Currently enabled: \(exampleButtonState)")
-                    }
-                    .padding(.bottom, 20)
+                    #if !canImport(UIKitBackend)
+                        VStack {
+                            Text("Toggle button")
+                            Toggle("Toggle me!", active: $exampleButtonState)
+                                .toggleStyle(.button)
+                            Text("Currently enabled: \(exampleButtonState)")
+                        }
+                        .padding(.bottom, 20)
+                    #endif
 
                     VStack {
                         Text("Toggle switch")
@@ -45,12 +47,14 @@ struct ControlsApp: App {
                         Text("Currently enabled: \(exampleSwitchState)")
                     }
 
-                    VStack {
-                        Text("Checkbox")
-                        Toggle("Toggle me:", active: $exampleCheckboxState)
-                            .toggleStyle(.checkbox)
-                        Text("Currently enabled: \(exampleCheckboxState)")
-                    }
+                    #if !canImport(UIKitBackend)
+                        VStack {
+                            Text("Checkbox")
+                            Toggle("Toggle me:", active: $exampleCheckboxState)
+                                .toggleStyle(.checkbox)
+                            Text("Currently enabled: \(exampleCheckboxState)")
+                        }
+                    #endif
 
                     VStack {
                         Text("Slider")

Package.swift

@@ -61,7 +61,7 @@ switch ProcessInfo.processInfo.environment["SCUI_LIBRARY_TYPE"] {
 
 let package = Package(
     name: "swift-cross-ui",
-    platforms: [.macOS(.v10_15), .iOS(.v13), .tvOS(.v13), .macCatalyst(.v13)],
+    platforms: [.macOS(.v10_15), .iOS(.v13), .tvOS(.v13), .macCatalyst(.v13), .visionOS(.v1)],
     products: [
         .library(name: "SwiftCrossUI", type: libraryType, targets: ["SwiftCrossUI"]),
         .library(name: "AppKitBackend", type: libraryType, targets: ["AppKitBackend"]),
@@ -162,7 +162,7 @@ let package = Package(
                 // on the compiling desktop, not the target.
                 .target(
                     name: "UIKitBackend",
-                    condition: .when(platforms: [.iOS, .tvOS, .macCatalyst])
+                    condition: .when(platforms: [.iOS, .tvOS, .macCatalyst, .visionOS])
                 ),
             ]
         ),

Sources/SwiftCrossUI/Values/TextStyle.swift

@@ -73,7 +73,7 @@ extension Font.TextStyle {
         .desktop: desktopTextStyles,
         .phone: mobileTextStyles,
         .tablet: mobileTextStyles,
-        .tv: tvTextStyles
+        .tv: tvTextStyles,
     ]
 
     private static let desktopTextStyles: [Self: Resolved] = [

Sources/UIKitBackend/KeyboardToolbar.swift

@@ -9,6 +9,7 @@ import UIKit
 /// containing the ``View/keyboardToolbar(animateChanges:body:)`` modifier is updated, so any
 /// state necessary for the toolbar should live in the view itself.
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 public protocol ToolbarItem {
     /// The type of bar button item used to represent this item in UIKit.
     associatedtype ItemType: UIBarButtonItem
@@ -23,6 +24,7 @@ public protocol ToolbarItem {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 @resultBuilder
 public enum ToolbarBuilder {
     public enum Component {
@@ -61,6 +63,7 @@ public enum ToolbarBuilder {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 extension Button: ToolbarItem {
     public final class ItemType: UIBarButtonItem {
         var callback: @MainActor @Sendable () -> Void
@@ -100,6 +103,7 @@ extension Button: ToolbarItem {
 // See https://forums.swift.org/t/contradictory-available-s-are-required/78831
 @available(iOS 14, macCatalyst 14, *)
 @available(tvOS, unavailable, introduced: 14)
+@available(visionOS, unavailable)
 extension Spacer: ToolbarItem {
     public func createBarButtonItem() -> UIBarButtonItem {
         if let minLength, minLength > 0 {
@@ -120,6 +124,7 @@ extension Spacer: ToolbarItem {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 struct FixedWidthToolbarItem<Base: ToolbarItem>: ToolbarItem {
     var base: Base
     var width: Int?
@@ -143,6 +148,7 @@ struct FixedWidthToolbarItem<Base: ToolbarItem>: ToolbarItem {
 // Setting width on a flexible space is ignored, you must use a fixed space from the outset
 @available(iOS 14, macCatalyst 14, *)
 @available(tvOS, unavailable, introduced: 14)
+@available(visionOS, unavailable)
 struct FixedWidthSpacerItem: ToolbarItem {
     var width: Int?
 
@@ -160,6 +166,7 @@ struct FixedWidthSpacerItem: ToolbarItem {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 struct ColoredToolbarItem<Base: ToolbarItem>: ToolbarItem {
     var base: Base
     var color: Color
@@ -177,6 +184,7 @@ struct ColoredToolbarItem<Base: ToolbarItem>: ToolbarItem {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 extension ToolbarItem {
     /// A toolbar item with the specified width.
     ///
@@ -199,6 +207,7 @@ extension ToolbarItem {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 indirect enum ToolbarItemLocation: Hashable {
     case expression(inside: ToolbarItemLocation?)
     case block(index: Int, inside: ToolbarItemLocation?)
@@ -209,6 +218,7 @@ indirect enum ToolbarItemLocation: Hashable {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 final class KeyboardToolbar: UIToolbar {
     var locations: [ToolbarItemLocation: UIBarButtonItem] = [:]
 
@@ -286,11 +296,13 @@ final class KeyboardToolbar: UIToolbar {
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 enum ToolbarKey: EnvironmentKey {
     static let defaultValue: ((KeyboardToolbar) -> Void)? = nil
 }
 
 @available(tvOS, unavailable)
+@available(visionOS, unavailable)
 extension EnvironmentValues {
     var updateToolbar: ((KeyboardToolbar) -> Void)? {
         get { self[ToolbarKey.self] }
@@ -305,6 +317,7 @@ extension View {
     ///     updated
     ///   - body: The toolbar's contents
     @available(tvOS, unavailable)
+    @available(visionOS, unavailable)
     public func keyboardToolbar(
         animateChanges: Bool = true,
         @ToolbarBuilder body: @escaping () -> ToolbarBuilder.FinalResult

Sources/UIKitBackend/UIKitBackend+Container.swift

@@ -59,16 +59,17 @@ final class ScrollWidget: ContainerWidget {
 
     public func updateScrollContainer(environment: EnvironmentValues) {
         #if os(iOS)
-            scrollView.keyboardDismissMode = switch environment.scrollDismissesKeyboardMode {
-                case .automatic:
-                    .interactive
-                case .immediately:
-                    .onDrag
-                case .interactively:
-                    .interactive
-                case .never:
-                    .none
-            }
+            scrollView.keyboardDismissMode =
+                switch environment.scrollDismissesKeyboardMode {
+                    case .automatic:
+                        .interactive
+                    case .immediately:
+                        .onDrag
+                    case .interactively:
+                        .interactive
+                    case .never:
+                        .none
+                }
         #endif
     }
 }

Sources/UIKitBackend/UIKitBackend+Control.swift

@@ -318,17 +318,22 @@ extension UIKitBackend {
                 textEditorWidget.child.inputAccessoryView = nil
             }
 
-            textEditorWidget.child.alwaysBounceVertical = environment.scrollDismissesKeyboardMode != .never
-            textEditorWidget.child.keyboardDismissMode = switch environment.scrollDismissesKeyboardMode {
-                case .automatic:
-                    textEditorWidget.child.inputAccessoryView == nil ? .interactive : .interactiveWithAccessory
-                case .immediately:
-                    textEditorWidget.child.inputAccessoryView == nil ? .onDrag : .onDragWithAccessory
-                case .interactively:
-                    textEditorWidget.child.inputAccessoryView == nil ? .interactive : .interactiveWithAccessory
-                case .never:
-                    .none
-            }
+            textEditorWidget.child.alwaysBounceVertical =
+                environment.scrollDismissesKeyboardMode != .never
+            textEditorWidget.child.keyboardDismissMode =
+                switch environment.scrollDismissesKeyboardMode {
+                    case .automatic:
+                        textEditorWidget.child.inputAccessoryView == nil
+                            ? .interactive : .interactiveWithAccessory
+                    case .immediately:
+                        textEditorWidget.child.inputAccessoryView == nil
+                            ? .onDrag : .onDragWithAccessory
+                    case .interactively:
+                        textEditorWidget.child.inputAccessoryView == nil
+                            ? .interactive : .interactiveWithAccessory
+                    case .never:
+                        .none
+                }
         #endif
     }
 
@@ -409,7 +414,7 @@ extension UIKitBackend {
         }
     }
 
-    #if os(iOS)
+    #if os(iOS) || os(visionOS)
         public func createSlider() -> Widget {
             SliderWidget()
         }

Sources/UIKitBackend/UIKitBackend+Window.swift

@@ -5,10 +5,27 @@ final class RootViewController: UIViewController {
     var resizeHandler: ((CGSize) -> Void)?
     private var childWidget: (any WidgetProtocol)?
 
-    init(backend: UIKitBackend) {
-        self.backend = backend
-        super.init(nibName: nil, bundle: nil)
-    }
+    #if os(visionOS)
+        init(backend: UIKitBackend) {
+            self.backend = backend
+            super.init(nibName: nil, bundle: nil)
+
+            registerForTraitChanges([UITraitUserInterfaceStyle.self]) {
+                (self: RootViewController, _: UITraitCollection) in
+                self.backend.onTraitCollectionChange?()
+            }
+        }
+    #else
+        init(backend: UIKitBackend) {
+            self.backend = backend
+            super.init(nibName: nil, bundle: nil)
+        }
+
+        override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
+            super.traitCollectionDidChange(previousTraitCollection)
+            backend.onTraitCollectionChange?()
+        }
+    #endif
 
     @available(*, unavailable)
     required init?(coder: NSCoder) {
@@ -29,11 +46,6 @@ final class RootViewController: UIViewController {
         resizeHandler?(size)
     }
 
-    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
-        super.traitCollectionDidChange(previousTraitCollection)
-        backend.onTraitCollectionChange?()
-    }
-
     func setChild(to child: some WidgetProtocol) {
         childWidget?.removeFromParentWidget()
         child.removeFromParentWidget()
@@ -110,19 +122,25 @@ extension UIKitBackend {
     }
 
     public func isWindowProgrammaticallyResizable(_ window: Window) -> Bool {
-        // On iPad, some windows are user-resizable, but UIKit windows are never
-        // programmatically resizable.
-        false
+        #if os(visionOS)
+            true
+        #else
+            false
+        #endif
     }
 
     public func setResizability(ofWindow window: Window, to resizable: Bool) {
         print("UIKitBackend: ignoring \(#function) call")
     }
 
     public func setSize(ofWindow window: Window, to newSize: SIMD2<Int>) {
-        print(
-            "UIKitBackend: ignoring \(#function) call. Current window size: \(window.bounds.width) x \(window.bounds.height); proposed size: \(newSize.x) x \(newSize.y)"
-        )
+        #if os(visionOS)
+            window.bounds.size = CGSize(width: CGFloat(newSize.x), height: CGFloat(newSize.y))
+        #else
+            print(
+                "UIKitBackend: ignoring \(#function) call. Current window size: \(window.bounds.width) x \(window.bounds.height); proposed size: \(newSize.x) x \(newSize.y)"
+            )
+        #endif
     }
 
     public func setMinimumSize(ofWindow window: Window, to minimumSize: SIMD2<Int>) {

Sources/UIKitBackend/UIKitBackend.swift

@@ -27,16 +27,18 @@ public final class UIKitBackend: AppBackend {
         switch UIDevice.current.userInterfaceIdiom {
             case .phone:
                 .phone
-            case .pad:
+            case .pad, .vision:
                 .tablet
             case .tv:
                 .tv
             case .mac:
                 .desktop
-            case .unspecified, .carPlay, .vision:
+            case .unspecified, .carPlay:
                 // Seems like the safest fallback for now given that we don't
                 // explicitly support these devices.
                 .tablet
+            @unknown default:
+                .tablet
         }
     }