Add SwiftUI App Lifecycle

NativeDemo/TokamakDemo.xcodeproj/project.pbxproj

@@ -33,6 +33,8 @@
 		B56F22E124BC89FD001738DF /* ColorDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56F22DF24BC89FD001738DF /* ColorDemo.swift */; };
 		B56F22E324BD1C26001738DF /* GridDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56F22E224BD1C26001738DF /* GridDemo.swift */; };
 		B56F22E424BD1C26001738DF /* GridDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56F22E224BD1C26001738DF /* GridDemo.swift */; };
+		B5C76E4A24C73ED5003EABB2 /* AppStorageDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5C76E4924C73ED4003EABB2 /* AppStorageDemo.swift */; };
+		B5C76E4B24C73ED5003EABB2 /* AppStorageDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5C76E4924C73ED4003EABB2 /* AppStorageDemo.swift */; };
 		D1B4229024B3B9BB00682F74 /* ListDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = D1B4228E24B3B9BB00682F74 /* ListDemo.swift */; };
 		D1B4229124B3B9BB00682F74 /* ListDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = D1B4228E24B3B9BB00682F74 /* ListDemo.swift */; };
 		D1B4229224B3B9BB00682F74 /* OutlineGroupDemo.swift in Sources */ = {isa = PBXBuildFile; fileRef = D1B4228F24B3B9BB00682F74 /* OutlineGroupDemo.swift */; };
@@ -93,6 +95,7 @@
 		B51F214F24B920B400CF2583 /* PathDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PathDemo.swift; sourceTree = "<group>"; };
 		B56F22DF24BC89FD001738DF /* ColorDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.swift; path = ColorDemo.swift; sourceTree = "<group>"; tabWidth = 2; };
 		B56F22E224BD1C26001738DF /* GridDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GridDemo.swift; sourceTree = "<group>"; };
+		B5C76E4924C73ED4003EABB2 /* AppStorageDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AppStorageDemo.swift; sourceTree = "<group>"; };
 		D1B4228E24B3B9BB00682F74 /* ListDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ListDemo.swift; sourceTree = "<group>"; };
 		D1B4228F24B3B9BB00682F74 /* OutlineGroupDemo.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OutlineGroupDemo.swift; sourceTree = "<group>"; };
 		D1E5FDA424C1D54B00E7485E /* libTokamakShim.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libTokamakShim.a; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -156,6 +159,7 @@
 		85ED189924AD425E0085DFA0 /* TokamakDemo */ = {
 			isa = PBXGroup;
 			children = (
+				B5C76E4924C73ED4003EABB2 /* AppStorageDemo.swift */,
 				D1EE7EA624C0DD2100C0D127 /* PickerDemo.swift */,
 				D1B4228E24B3B9BB00682F74 /* ListDemo.swift */,
 				D1B4228F24B3B9BB00682F74 /* OutlineGroupDemo.swift */,
@@ -269,7 +273,7 @@
 					};
 				};
 			};
-			buildConfigurationList = 85ED184124AD37970085DFA0 /* Build configuration list for PBXProject "TokamakDemo Native" */;
+			buildConfigurationList = 85ED184124AD37970085DFA0 /* Build configuration list for PBXProject "TokamakDemo" */;
 			compatibilityVersion = "Xcode 9.3";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
@@ -323,6 +327,7 @@
 				D1B4229024B3B9BB00682F74 /* ListDemo.swift in Sources */,
 				D1EE7EA724C0DD2100C0D127 /* PickerDemo.swift in Sources */,
 				85ED18A924AD425E0085DFA0 /* TokamakDemo.swift in Sources */,
+				B5C76E4A24C73ED5003EABB2 /* AppStorageDemo.swift in Sources */,
 				85ED18AD24AD425E0085DFA0 /* TextFieldDemo.swift in Sources */,
 				85ED18A724AD425E0085DFA0 /* ForEachDemo.swift in Sources */,
 				854A1A9124B3E3630027BC32 /* ToggleDemo.swift in Sources */,
@@ -345,6 +350,7 @@
 				D1B4229124B3B9BB00682F74 /* ListDemo.swift in Sources */,
 				D1EE7EA824C0DD2100C0D127 /* PickerDemo.swift in Sources */,
 				85ED18B624AD42D70085DFA0 /* NSAppDelegate.swift in Sources */,
+				B5C76E4B24C73ED5003EABB2 /* AppStorageDemo.swift in Sources */,
 				85ED18AC24AD425E0085DFA0 /* Counter.swift in Sources */,
 				85ED18A824AD425E0085DFA0 /* ForEachDemo.swift in Sources */,
 				854A1A9324B3F28F0027BC32 /* ToggleDemo.swift in Sources */,
@@ -613,7 +619,7 @@
 /* End XCBuildConfiguration section */
 
 /* Begin XCConfigurationList section */
-		85ED184124AD37970085DFA0 /* Build configuration list for PBXProject "TokamakDemo Native" */ = {
+		85ED184124AD37970085DFA0 /* Build configuration list for PBXProject "TokamakDemo" */ = {
 			isa = XCConfigurationList;
 			buildConfigurations = (
 				85ED185C24AD379B0085DFA0 /* Debug */,

Package.resolved

@@ -5,8 +5,8 @@
         "package": "JavaScriptKit",
         "repositoryURL": "https://github.com/kateinoigakukun/JavaScriptKit.git",
         "state": {
-          "branch": "47f2bb1",
-          "revision": "47f2bb16576ba386a2c7c69c97b0fd44f470126f",
+          "branch": "c90e82f",
+          "revision": "c90e82fe1d576a2ccd1aae798380bf80be7885fb",
           "version": null
         }
       },

Package.swift

@@ -29,7 +29,7 @@ let package = Package(
   dependencies: [
     // Dependencies declare other packages that this package depends on.
     // .package(url: /* package url */, from: "1.0.0"),
-    .package(url: "https://github.com/kateinoigakukun/JavaScriptKit.git", .revision("47f2bb1")),
+    .package(url: "https://github.com/kateinoigakukun/JavaScriptKit.git", .revision("c90e82f")),
     .package(url: "https://github.com/MaxDesiatov/Runtime.git", .branch("wasi-build")),
     .package(url: "https://github.com/MaxDesiatov/OpenCombine.git", .branch("observable-object")),
   ],

Sources/TokamakCore/App/App.swift

@@ -0,0 +1,47 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//  Created by Carson Katri on 7/16/20.
+//
+
+import OpenCombine
+import Runtime
+
+/// Provides the ability to set the title of the Scene.
+public protocol _TitledApp {
+  static func _setTitle(_ title: String)
+}
+
+/// The renderer is responsible for implementing certain functionality.
+public protocol App: _TitledApp {
+  associatedtype Body: Scene
+  var body: Body { get }
+
+  /// Implemented by the renderer to mount the `App`
+  static func _launch(_ app: Self,
+                      _ rootEnvironment: EnvironmentValues)
+  /// Implemented by the renderer to update the `App` on `ScenePhase` changes
+  var _phasePublisher: CurrentValueSubject<ScenePhase, Never> { get }
+
+  static func main()
+
+  init()
+}
+
+extension App {
+  public static func main() {
+    let app = Self()
+    _launch(app, EnvironmentValues())
+  }
+}

Sources/TokamakCore/App/AppStorage.swift

@@ -0,0 +1,192 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//  Created by Carson Katri on 7/16/20.
+//
+
+import OpenCombine
+
+@propertyWrapper public struct AppStorage<Value>: ObservedProperty {
+  let provider: _StorageProvider?
+  @Environment(\._defaultAppStorage) var defaultProvider: _StorageProvider?
+  var unwrappedProvider: _StorageProvider {
+    provider ?? defaultProvider!
+  }
+
+  let key: String
+  let defaultValue: Value
+  let store: (_StorageProvider, String, Value) -> ()
+  let read: (_StorageProvider, String) -> Value?
+
+  var objectWillChange: AnyPublisher<(), Never> {
+    unwrappedProvider.publisher.eraseToAnyPublisher()
+  }
+
+  public var wrappedValue: Value {
+    get {
+      read(unwrappedProvider, key) ?? defaultValue
+    }
+    nonmutating set {
+      store(unwrappedProvider, key, newValue)
+    }
+  }
+
+  public var projectedValue: Binding<Value> {
+    .init {
+      wrappedValue
+    } set: {
+      wrappedValue = $0
+    }
+  }
+}
+
+extension AppStorage: DynamicProperty {}
+
+extension AppStorage {
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Bool {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Int {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Double {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == String {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil)
+    where Value: RawRepresentable, Value.RawValue == Int {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2.rawValue) }
+    read = {
+      guard let rawValue = $0.read(key: $1) as Int? else {
+        return nil
+      }
+      return Value(rawValue: rawValue)
+    }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil)
+    where Value: RawRepresentable, Value.RawValue == String {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2.rawValue) }
+    read = {
+      guard let rawValue = $0.read(key: $1) as String? else {
+        return nil
+      }
+      return Value(rawValue: rawValue)
+    }
+  }
+}
+
+extension AppStorage where Value: ExpressibleByNilLiteral {
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Bool? {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Int? {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == Double? {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+
+  public init(wrappedValue: Value,
+              _ key: String,
+              store: _StorageProvider? = nil) where Value == String? {
+    defaultValue = wrappedValue
+    self.key = key
+    provider = store
+    self.store = { $0.store(key: $1, value: $2) }
+    read = { $0.read(key: $1) }
+  }
+}
+
+/// The renderer is responsible for making sure a default is set at the root of the App.
+struct DefaultAppStorageEnvironmentKey: EnvironmentKey {
+  static let defaultValue: _StorageProvider? = nil
+}
+
+extension EnvironmentValues {
+  public var _defaultAppStorage: _StorageProvider? {
+    get {
+      self[DefaultAppStorageEnvironmentKey.self]
+    }
+    set {
+      self[DefaultAppStorageEnvironmentKey.self] = newValue
+    }
+  }
+}
+
+extension View {
+  public func defaultAppStorage(_ store: _StorageProvider) -> some View {
+    environment(\._defaultAppStorage, store)
+  }
+}

Sources/TokamakCore/App/Scenes/Scene.swift

@@ -0,0 +1,49 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//  Created by Carson Katri on 7/16/20.
+//
+
+public protocol Scene {
+  associatedtype Body: Scene
+
+  // FIXME: If I put `@SceneBuilder` in front of this
+  // it fails to build with no useful error message.
+  var body: Self.Body { get }
+}
+
+protocol TitledScene {
+  var title: Text? { get }
+}
+
+protocol ViewContainingScene {
+  var anyContent: AnyView { get }
+}
+
+protocol ParentScene {
+  var children: [_AnyScene] { get }
+}
+
+protocol GroupScene: ParentScene {}
+
+public protocol SceneDeferredToRenderer {
+  var deferredBody: AnyView { get }
+}
+
+extension Never: Scene {}
+
+/// Calls `fatalError` with an explanation that a given `type` is a primitive `Scene`
+public func neverScene(_ type: String) -> Never {
+  fatalError("\(type) is a primitive `Scene`, you're not supposed to access its `body`.")
+}