Support @Observable view models

.github/workflows/build.yml

@@ -0,0 +1,28 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build-ios:
+    name: Build for iOS
+    runs-on: macos-15
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Select Xcode
+        uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: latest-stable
+
+      - name: Build CarPlayDemo for iOS Simulator
+        run: |
+          xcodebuild build \
+            -project Xcode/CarPlayDemo.xcodeproj \
+            -scheme CarPlayDemo \
+            -destination 'generic/platform=iOS Simulator'

Package.swift

@@ -1,9 +1,9 @@
-// swift-tools-version: 6.0
+// swift-tools-version: 6.2
 import PackageDescription
 
 let package = Package(
     name: "CarPlayUI",
-    platforms: [.iOS(.v13)],
+    platforms: [.iOS(.v17)],
     products: [
         .library(
             name: "CarPlayUI",
@@ -14,14 +14,18 @@ let package = Package(
         .target(
             name: "CarPlayUI",
             swiftSettings: [
-                .swiftLanguageMode(.v6)
+                .swiftLanguageMode(.v6),
+                .enableUpcomingFeature("InferIsolatedConformances"),
+                .enableUpcomingFeature("NonisolatedNonsendingByDefault")
             ]
         ),
         .testTarget(
             name: "CarPlayUITests",
             dependencies: ["CarPlayUI"],
             swiftSettings: [
-                .swiftLanguageMode(.v6)
+                .swiftLanguageMode(.v6),
+                .enableUpcomingFeature("InferIsolatedConformances"),
+                .enableUpcomingFeature("NonisolatedNonsendingByDefault")
             ]
         )
     ]

Sources/CarPlayUI/Extensions/CPGridButton.swift

@@ -10,6 +10,7 @@ import CarPlay
 
 internal extension CPGridButton {
 
+    @MainActor
     convenience init(label: ParentView, action: @escaping (CPGridButton) -> ()) {
         // extract labels
         var labels = label.children.compactMap {

Sources/CarPlayUI/Extensions/CPPointOfInterest.swift

@@ -11,6 +11,7 @@ import CarPlay
 @available(iOS 14.0, *)
 internal extension CPPointOfInterest {
 
+    @MainActor
     convenience init(_ view: ViewObject) {
         if #available(iOS 16.0, *) {
             self.init(

Sources/CarPlayUI/Extensions/CPTextButton.swift

@@ -11,6 +11,7 @@ import CarPlay
 @available(iOS 14.0, *)
 internal extension CPTextButton {
 
+    @MainActor
     convenience init(button: Button<Text>) {
         let title = _TextProxy(button.label).rawText
         let textStyle = CPTextButtonStyle(role: button.role)

Sources/CarPlayUI/Extensions/UIImage.swift

@@ -11,6 +11,7 @@ import CarPlay
 
 internal extension UIImage {
 
+    @MainActor
     convenience init?(
         _ image: _ImageProxy,
         environment: EnvironmentValues = .defaultEnvironment
@@ -38,6 +39,7 @@ internal extension UIImage {
         }
     }
 
+    @MainActor
     static func unsafe(
         _ image: Image,
         environment: EnvironmentValues = .defaultEnvironment,
@@ -46,7 +48,8 @@ internal extension UIImage {
     ) -> UIImage {
         unsafe(_ImageProxy(image), environment: environment, file: file, line: line)
     }
-
+
+    @MainActor
     static func unsafe(
         _ image: _ImageProxy,
         environment: EnvironmentValues = .defaultEnvironment,

Sources/CarPlayUI/TokamakCore/Animation/Animatable.swift

@@ -18,8 +18,8 @@
 import Foundation
 
 public protocol Animatable {
-  associatedtype AnimatableData: VectorArithmetic
-  var animatableData: Self.AnimatableData { get set }
+  associatedtype _AnimatableData: VectorArithmetic
+  var animatableData: Self._AnimatableData { get set }
 }
 
 public protocol _PrimitiveAnimatable {}
@@ -32,7 +32,7 @@ public extension Animatable where Self: VectorArithmetic {
   }
 }
 
-public extension Animatable where Self.AnimatableData == EmptyAnimatableData {
+public extension Animatable where Self._AnimatableData == EmptyAnimatableData {
   var animatableData: EmptyAnimatableData {
     @inlinable get { EmptyAnimatableData() }
     // swiftlint:disable:next unused_setter_value
@@ -140,26 +140,34 @@ public struct AnimatablePair<First, Second>: VectorArithmetic
 }
 
 extension CGPoint: Animatable {
-  public var animatableData: AnimatablePair<CGFloat, CGFloat> {
+  public typealias _AnimatableData = AnimatablePair<CGFloat, CGFloat>
+  public var animatableData: _AnimatableData {
     @inlinable get { .init(x, y) }
     @inlinable set { (x, y) = newValue[] }
   }
 }
 
 extension CGSize: Animatable {
-  public var animatableData: AnimatablePair<CGFloat, CGFloat> {
+  public typealias _AnimatableData = AnimatablePair<CGFloat, CGFloat>
+  public var animatableData: _AnimatableData {
     @inlinable get { .init(width, height) }
     @inlinable set { (width, height) = newValue[] }
   }
 }
 
 extension CGRect: Animatable {
-  public var animatableData: AnimatablePair<CGPoint.AnimatableData, CGSize.AnimatableData> {
+  public typealias _AnimatableData = AnimatablePair<AnimatablePair<CGFloat, CGFloat>, AnimatablePair<CGFloat, CGFloat>>
+  public var animatableData: _AnimatableData {
     @inlinable get {
-      .init(origin.animatableData, size.animatableData)
+      .init(
+        AnimatablePair(origin.x, origin.y),
+        AnimatablePair(size.width, size.height)
+      )
     }
     @inlinable set {
-      (origin.animatableData, size.animatableData) = newValue[]
+      let value = newValue[]
+      origin = .init(x: value.0[].0, y: value.0[].1)
+      size = .init(width: value.1[].0, height: value.1[].1)
     }
   }
 }

Sources/CarPlayUI/TokamakCore/Animation/Animation.swift

@@ -143,8 +143,8 @@ public struct _AnimationProxy {
 public struct _AnimationModifier<Value>: ViewModifier, Equatable
   where Value: Equatable
 {
-  public var animation: Animation?
-  public var value: Value
+  public nonisolated(unsafe) var animation: Animation?
+  public nonisolated(unsafe) var value: Value
 
   @inlinable
   public init(animation: Animation?, value: Value) {
@@ -155,10 +155,9 @@ public struct _AnimationModifier<Value>: ViewModifier, Equatable
   private struct ContentWrapper: View, Equatable {
     let content: Content
     let animation: Animation?
-    let value: Value
+    nonisolated(unsafe) let value: Value
 
-    @State
-    private var lastValue: Value?
+    @State private nonisolated(unsafe) var lastValue: Value?
 
     var body: some View {
       content.transaction {
@@ -168,7 +167,7 @@ public struct _AnimationModifier<Value>: ViewModifier, Equatable
       }
     }
 
-    static func == (lhs: Self, rhs: Self) -> Bool {
+    nonisolated static func == (lhs: Self, rhs: Self) -> Bool {
       lhs.value == rhs.value
     }
   }
@@ -177,7 +176,7 @@ public struct _AnimationModifier<Value>: ViewModifier, Equatable
     ContentWrapper(content: content, animation: animation, value: value)
   }
 
-  public static func == (lhs: Self, rhs: Self) -> Bool {
+  public nonisolated static func == (lhs: Self, rhs: Self) -> Bool {
     lhs.value == rhs.value
       && lhs.animation == rhs.animation
   }

Sources/CarPlayUI/TokamakCore/Fiber/Fiber+Content.swift

@@ -20,11 +20,11 @@ import Foundation
 public extension FiberReconciler.Fiber {
   enum Content {
     /// The underlying `App` instance and a function to visit it generically.
-    case app(Any, visit: (AppVisitor) -> ())
+    case app(Any, visit: @MainActor (AppVisitor) -> ())
     /// The underlying `Scene` instance and a function to visit it generically.
-    case scene(Any, visit: (SceneVisitor) -> ())
+    case scene(Any, visit: @MainActor (SceneVisitor) -> ())
     /// The underlying `View` instance and a function to visit it generically.
-    case view(Any, visit: (ViewVisitor) -> ())
+    case view(Any, visit: @MainActor (ViewVisitor) -> ())
   }
 
   /// Create a `Content` value for a given `App`.

Sources/CarPlayUI/TokamakCore/Fiber/Fiber+CustomDebugStringConvertible.swift

@@ -16,14 +16,16 @@
 //
 
 extension FiberReconciler.Fiber: CustomDebugStringConvertible {
-  public var debugDescription: String {
-    let memoryAddress = String(format: "%010p", unsafeBitCast(self, to: Int.self))
-    if case let .view(view, _) = content,
-       let text = view as? Text
-    {
-      return "Text(\"\(text.storage.rawText)\") (\(memoryAddress))"
+  public nonisolated var debugDescription: String {
+    MainActor.assumeIsolated {
+      let memoryAddress = String(format: "%010p", unsafeBitCast(self, to: Int.self))
+      if case let .view(view, _) = content,
+         let text = view as? Text
+      {
+        return "Text(\"\(text.storage.rawText)\") (\(memoryAddress))"
+      }
+      return "\(typeInfo?.name ?? "Unknown") (\(memoryAddress))"
     }
-    return "\(typeInfo?.name ?? "Unknown") (\(memoryAddress))"
   }
 
   private func flush(level: Int = 0) -> String {

Sources/CarPlayUI/TokamakCore/Fiber/Fiber.swift

@@ -39,6 +39,7 @@ public extension FiberReconciler {
   /// After the entire tree has been traversed, the current and work in progress trees are swapped,
   /// making the updated tree the current one,
   /// and leaving the previous current tree available to apply future changes on.
+  @MainActor
   final class Fiber {
     weak var reconciler: FiberReconciler<Renderer>?
 

Sources/CarPlayUI/TokamakCore/Fiber/FiberReconciler.swift

@@ -20,6 +20,7 @@ import Combine
 
 /// A reconciler modeled after React's
 /// [Fiber reconciler](https://reactjs.org/docs/faq-internals.html#what-is-react-fiber)
+@MainActor
 public final class FiberReconciler<Renderer: FiberRenderer> {
   /// The root node in the `Fiber` tree that represents the `View`s currently rendered on screen.
 
@@ -283,6 +284,7 @@ public extension EnvironmentValues {
     static let defaultValue: (@escaping () -> ()) -> () = { _ in }
   }
 
+  @MainActor
   var afterReconcile: (@escaping () -> ()) -> () {
     get { self[AfterReconcileKey.self] }
     set { self[AfterReconcileKey.self] = newValue }

Sources/CarPlayUI/TokamakCore/Fiber/FiberRenderer.swift

@@ -128,6 +128,7 @@ extension EnvironmentValues {
     }
   }
 
+  @MainActor
   var measureText: (Text, ProposedViewSize, EnvironmentValues) -> CGSize {
     get { self[MeasureTextKey.self] }
     set { self[MeasureTextKey.self] = newValue }
@@ -139,6 +140,7 @@ extension EnvironmentValues {
     }
   }
 
+  @MainActor
   var measureImage: (Image, ProposedViewSize, EnvironmentValues) -> CGSize {
     get { self[MeasureImageKey.self] }
     set { self[MeasureImageKey.self] = newValue }

Sources/CarPlayUI/TokamakCore/Fiber/Layout/Layout.swift

@@ -286,11 +286,11 @@ protocol AnyLayoutBox: AnyObject {
     cache: inout Self.Cache
   ) -> CGFloat?
 
-  var animatableData: _AnyAnimatableData { get set }
+  nonisolated var animatableData: _AnyAnimatableData { get set }
 }
 
 final class ConcreteLayoutBox<L: Layout>: AnyLayoutBox {
-  var base: L
+  nonisolated(unsafe) var base: L
 
   init(_ base: L) {
     self.base = base
@@ -381,20 +381,20 @@ final class ConcreteLayoutBox<L: Layout>: AnyLayoutBox {
     }
   }
 
-  var animatableData: _AnyAnimatableData {
+  nonisolated var animatableData: _AnyAnimatableData {
     get {
       .init(base.animatableData)
     }
     set {
-      guard let newData = newValue.value as? L.AnimatableData else { return }
+      guard let newData = newValue.value as? L._AnimatableData else { return }
       base.animatableData = newData
     }
   }
 }
 
 @frozen
 public struct AnyLayout: Layout {
-  var storage: AnyLayoutBox
+  nonisolated(unsafe) var storage: AnyLayoutBox
 
   public init<L>(_ layout: L) where L: Layout {
     storage = ConcreteLayoutBox(layout)
@@ -469,7 +469,7 @@ public struct AnyLayout: Layout {
     )
   }
 
-  public var animatableData: _AnyAnimatableData {
+  public nonisolated var animatableData: _AnyAnimatableData {
     get {
       _AnyAnimatableData(storage.animatableData)
     }