Removed the view model class and added an icon.

Shared/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,148 +1 @@
-{
-  "images" : [
-    {
-      "idiom" : "iphone",
-      "scale" : "2x",
-      "size" : "20x20"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "3x",
-      "size" : "20x20"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "2x",
-      "size" : "29x29"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "3x",
-      "size" : "29x29"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "2x",
-      "size" : "40x40"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "3x",
-      "size" : "40x40"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "2x",
-      "size" : "60x60"
-    },
-    {
-      "idiom" : "iphone",
-      "scale" : "3x",
-      "size" : "60x60"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "1x",
-      "size" : "20x20"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "2x",
-      "size" : "20x20"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "1x",
-      "size" : "29x29"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "2x",
-      "size" : "29x29"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "1x",
-      "size" : "40x40"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "2x",
-      "size" : "40x40"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "1x",
-      "size" : "76x76"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "2x",
-      "size" : "76x76"
-    },
-    {
-      "idiom" : "ipad",
-      "scale" : "2x",
-      "size" : "83.5x83.5"
-    },
-    {
-      "idiom" : "ios-marketing",
-      "scale" : "1x",
-      "size" : "1024x1024"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "1x",
-      "size" : "16x16"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "2x",
-      "size" : "16x16"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "1x",
-      "size" : "32x32"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "2x",
-      "size" : "32x32"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "1x",
-      "size" : "128x128"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "2x",
-      "size" : "128x128"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "1x",
-      "size" : "256x256"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "2x",
-      "size" : "256x256"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "1x",
-      "size" : "512x512"
-    },
-    {
-      "idiom" : "mac",
-      "scale" : "2x",
-      "size" : "512x512"
-    }
-  ],
-  "info" : {
-    "author" : "xcode",
-    "version" : 1
-  }
-}
+{"images":[{"size":"60x60","expected-size":"180","filename":"180.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"3x"},{"size":"40x40","expected-size":"80","filename":"80.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"2x"},{"size":"40x40","expected-size":"120","filename":"120.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"3x"},{"size":"60x60","expected-size":"120","filename":"120.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"2x"},{"size":"57x57","expected-size":"57","filename":"57.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"1x"},{"size":"29x29","expected-size":"58","filename":"58.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"2x"},{"size":"29x29","expected-size":"29","filename":"29.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"1x"},{"size":"29x29","expected-size":"87","filename":"87.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"3x"},{"size":"57x57","expected-size":"114","filename":"114.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"2x"},{"size":"20x20","expected-size":"40","filename":"40.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"2x"},{"size":"20x20","expected-size":"60","filename":"60.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"iphone","scale":"3x"},{"size":"1024x1024","filename":"1024.png","expected-size":"1024","idiom":"ios-marketing","folder":"Assets.xcassets/AppIcon.appiconset/","scale":"1x"},{"size":"40x40","expected-size":"80","filename":"80.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"72x72","expected-size":"72","filename":"72.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"76x76","expected-size":"152","filename":"152.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"50x50","expected-size":"100","filename":"100.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"29x29","expected-size":"58","filename":"58.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"76x76","expected-size":"76","filename":"76.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"29x29","expected-size":"29","filename":"29.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"50x50","expected-size":"50","filename":"50.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"72x72","expected-size":"144","filename":"144.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"40x40","expected-size":"40","filename":"40.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"83.5x83.5","expected-size":"167","filename":"167.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"20x20","expected-size":"20","filename":"20.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"1x"},{"size":"20x20","expected-size":"40","filename":"40.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"ipad","scale":"2x"},{"size":"128x128","expected-size":"128","filename":"128.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"1x"},{"size":"256x256","expected-size":"256","filename":"256.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"1x"},{"size":"128x128","expected-size":"256","filename":"256.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"2x"},{"size":"256x256","expected-size":"512","filename":"512.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"2x"},{"size":"32x32","expected-size":"32","filename":"32.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"1x"},{"size":"512x512","expected-size":"512","filename":"512.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"1x"},{"size":"16x16","expected-size":"16","filename":"16.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"1x"},{"size":"16x16","expected-size":"32","filename":"32.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"2x"},{"size":"32x32","expected-size":"64","filename":"64.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"2x"},{"size":"512x512","expected-size":"1024","filename":"1024.png","folder":"Assets.xcassets/AppIcon.appiconset/","idiom":"mac","scale":"2x"}]}

Shared/ContentView.swift

@@ -1,40 +1,44 @@
 import SwiftUI
 
 struct ContentView: View {
-    @StateObject var model = ViewModel()
+    @State private var game = TicTacToe(startingPlayer: .x)
+
+    /// A Boolean value to check whether the game
+    /// mode is player-vs-enemy or player-vs-player.
+    @State private var isPVE = true
+
+    /// True iff the grid will reset.
+    @State private var willReset = false
 
     var body: some View {
         VStack {
-            Text(model.displayedMessage)
+            Text(displayedMessage)
                 .font(.title2)
                 .bold()
-                .opacity(model.isAnimating ? 0 : 1)
-                .animation(.default, value: model.isAnimating)
 
             Spacer()
 
-            GridView(model: model,
+            GridView(game: $game,
+                     willReset: $willReset,
+                     isPVE: isPVE,
                      lineWidth: 7.5)
             .padding()
 
             Spacer()
 
             HStack {
                 Button {
-                    Task {
-                        await model.switchGameMode()
-                    }
+                    isPVE.toggle()
+                    willReset.toggle()
                 } label: {
-                    Image(systemName: model.isPVE ? "person" : "person.2")
+                    Image(systemName: isPVE ? "person" : "person.2")
                         .foregroundColor(.blue)
                 }
 
                 Spacer()
 
                 Button {
-                    Task {
-                        await model.startNewGame()
-                    }
+                    willReset.toggle()
                 } label: {
                     Image(systemName: "arrow.counterclockwise")
                         .foregroundColor(.red)
@@ -46,9 +50,28 @@ struct ContentView: View {
             .font(.title)
         }
         .padding()
-        #if os(macOS)
-        .frame(minWidth: 350, minHeight: 400)
-        #endif
+    }
+
+    /// The up-to-date displayed message.
+    private var displayedMessage: String {
+        if game.hasNotEnded {
+            // If we are in pve mode, we don't need to check
+            // if the current player is x because the text
+            // is hidden while the opponent is playing.
+            return isPVE ? "Your turn!" : "Player \(game.currentPlayer)"
+        }
+        // Game has ended. Check for draws first.
+        guard let winner = game.winner else { return "Draw!" }
+        if isPVE {
+            // The AI is always player o.
+            switch winner {
+            case .x:
+                return "You won!"
+            case .o:
+                return "You lost!"
+            }
+        }
+        return "Player \(winner) won!"
     }
 }
 

Shared/GridView.swift

@@ -1,48 +1,121 @@
 import SwiftUI
 
+extension Task where Success == Never, Failure == Never {
+    /// Suspends the current task for the given time in seconds.
+    static func sleep(seconds: Double) async {
+        do {
+            try await Task.sleep(nanoseconds: UInt64(seconds * 1e9))
+        } catch {
+            #if DEBUG
+            print("Task interrupted unexpectedly")
+            #endif
+        }
+    }
+}
+
 /// A 3x3 grid of evenly-spaced cells.
 struct GridView: View {
-    @ObservedObject var model: ViewModel
+    @Binding var game: TicTacToe
+
+    @Binding var willReset: Bool
+
+    let isPVE: Bool
 
     /// The width of the drawing line.
     let lineWidth: Double
 
+    /// True iff an animation is occuring.
+    @State private var isAnimating = true
+
+    /// The completion percentage of the
+    /// grid lines animation.
+    @State private var animationCompletion = 0.0
+
+    /// The completion percentage of each
+    /// cell's drawing animation.
+    @State private var cellAnimationCompletions = Array(repeating: 0.0,
+                                                        count: 9)
+
     var body: some View {
         VStack(spacing: lineWidth) {
             ForEach(0..<3) { row in
                 HStack(spacing: lineWidth) {
                     ForEach(0..<3) { column in
-                        let index = 3 * row + column
-                        Button {
-                            Task {
-                                guard !model.game.hasEnded else {
-                                    await model.startNewGame()
-                                    return
-                                }
-                                await model.play(at: index)
-                            }
-                        } label: {
-                            Cell(player: model.game.grid[index],
-                                 isMatching: model.game.isMatching(at: index),
-                                 lineWidth: lineWidth,
-                                 animationCompletion: model.cellAnimationCompletions[index])
-                        }
-                        .buttonStyle(.borderless)
-                        .disabled(!model.game.isEmpty(at: index) &&
-                                  !model.game.hasEnded)
+                        button(at: 3 * row + column)
                     }
                 }
             }
         }
         .aspectRatio(1, contentMode: .fit)
         .background(GridLines(lineWidth: lineWidth,
-                              animationCompletion: model.gridAnimationCompletion))
+                              animationCompletion: animationCompletion))
+        .onChange(of: willReset) { willReset in
+            if willReset {
+                Task {
+                    await self.reset()
+                    self.willReset = false
+                }
+            }
+        }
         .task {
-            await model.startGridAnimation()
+            animationCompletion = 1
+            await Task.sleep(seconds: 1)
+            isAnimating.toggle()
+        }
+        .disabled(isAnimating)
+    }
+
+    /// Returns the button at the given index.
+    private func button(at index: Int) -> some View {
+        Button {
+            Task {
+                guard game.hasNotEnded else {
+                    await self.reset()
+                    return
+                }
+                await play(at: index)
+            }
+        } label: {
+            Cell(player: game.grid[index],
+                 isMatching: game.isMatching(at: index),
+                 lineWidth: lineWidth,
+                 animationCompletion: cellAnimationCompletions[index])
+        }
+        .buttonStyle(.borderless)
+        .disabled(!game.isEmpty(at: index) && game.hasNotEnded)
+    }
+
+    /// Sets the current-turn player at `index`,
+    /// and returns after the cell's animation completes.
+    private func setPlayer(at index: Int) async {
+        game.play(at: index)
+        withAnimation(Cell.animation) {
+            cellAnimationCompletions[index] = 1
+        }
+        await Task.sleep(seconds: Cell.animationDuration)
+    }
+
+    /// Plays the game at `index`.
+    private func play(at index: Int) async {
+        isAnimating.toggle()
+        await setPlayer(at: index)
+        if isPVE, let move = game.moveHavingBestHeuristic() {
+            await setPlayer(at: move)
+        }
+        isAnimating.toggle()
+    }
+
+    /// Resets the grid.
+    func reset() async {
+        // Only reset when needed.
+        guard !game.isFirstTurn else { return }
+        isAnimating.toggle()
+        withAnimation(Cell.animation) {
+            cellAnimationCompletions = Array(repeating: 0,
+                                             count: 9)
         }
-        .disabled(model.isAnimating)
-        #if os(macOS)
-        .frame(minWidth: 300)
-        #endif
+        await Task.sleep(seconds: Cell.animationDuration)
+        game = TicTacToe(startingPlayer: .x)
+        isAnimating.toggle()
     }
 }