refactor(view, model, viewmodel): 优化代码写法

优化代码写法

Signed-off-by: Ching <loooching@gmail.com>

Memorize.xcodeproj/project.pbxproj

@@ -8,7 +8,7 @@
 
 /* Begin PBXBuildFile section */
 		240EDC3F2998A3B900A46AC9 /* MemorizeApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = 240EDC3E2998A3B900A46AC9 /* MemorizeApp.swift */; };
-		240EDC412998A3B900A46AC9 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 240EDC402998A3B900A46AC9 /* ContentView.swift */; };
+		240EDC412998A3B900A46AC9 /* EmojiMemoryGameView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 240EDC402998A3B900A46AC9 /* EmojiMemoryGameView.swift */; };
 		240EDC432998A3BA00A46AC9 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 240EDC422998A3BA00A46AC9 /* Assets.xcassets */; };
 		240EDC462998A3BA00A46AC9 /* Preview Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 240EDC452998A3BA00A46AC9 /* Preview Assets.xcassets */; };
 		245099F32998EAD6000CE9DA /* MemoryGame.swift in Sources */ = {isa = PBXBuildFile; fileRef = 245099F22998EAD6000CE9DA /* MemoryGame.swift */; };
@@ -18,7 +18,7 @@
 /* Begin PBXFileReference section */
 		240EDC3B2998A3B900A46AC9 /* Memorize.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Memorize.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		240EDC3E2998A3B900A46AC9 /* MemorizeApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemorizeApp.swift; sourceTree = "<group>"; };
-		240EDC402998A3B900A46AC9 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
+		240EDC402998A3B900A46AC9 /* EmojiMemoryGameView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmojiMemoryGameView.swift; sourceTree = "<group>"; };
 		240EDC422998A3BA00A46AC9 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		240EDC452998A3BA00A46AC9 /* Preview Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = "Preview Assets.xcassets"; sourceTree = "<group>"; };
 		245099F22998EAD6000CE9DA /* MemoryGame.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryGame.swift; sourceTree = "<group>"; };
@@ -56,7 +56,7 @@
 			isa = PBXGroup;
 			children = (
 				240EDC3E2998A3B900A46AC9 /* MemorizeApp.swift */,
-				240EDC402998A3B900A46AC9 /* ContentView.swift */,
+				240EDC402998A3B900A46AC9 /* EmojiMemoryGameView.swift */,
 				245099F22998EAD6000CE9DA /* MemoryGame.swift */,
 				245099F42998EC71000CE9DA /* EmojiMemoryGame.swift */,
 				240EDC422998A3BA00A46AC9 /* Assets.xcassets */,
@@ -144,7 +144,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				245099F32998EAD6000CE9DA /* MemoryGame.swift in Sources */,
-				240EDC412998A3B900A46AC9 /* ContentView.swift in Sources */,
+				240EDC412998A3B900A46AC9 /* EmojiMemoryGameView.swift in Sources */,
 				240EDC3F2998A3B900A46AC9 /* MemorizeApp.swift in Sources */,
 				245099F52998EC71000CE9DA /* EmojiMemoryGame.swift in Sources */,
 			);

Memorize/EmojiMemoryGame.swift

@@ -8,22 +8,23 @@
 import SwiftUI
 
 // viewmodel
-class EmojiMemoryGame: ObservableObject{
+class EmojiMemoryGame: ObservableObject {
+    typealias Card = MemoryGame<String>.Card
     static let emojis = ["🚌", "🚙", "🚗", "🚕", "🏎", "🚎", "🚓"]
 
     static func createMemoryGame() -> MemoryGame<String> {
-        MemoryGame<String>(numberOfPairsOfCards: 5) { pairIndex in EmojiMemoryGame.emojis[pairIndex] }
+        MemoryGame<String>(numberOfPairsOfCards: emojis.count) { pairIndex in EmojiMemoryGame.emojis[pairIndex] }
     }
 
-    @Published private var model: MemoryGame<String> = createMemoryGame()
+    @Published private var model = createMemoryGame()
 
-    var cards: [MemoryGame<String>.Card] {
+    var cards: [Card] {
         return model.cards
     }
 
     // MARK: - Intent(s)
 
-    func choose(_ card: MemoryGame<String>.Card) {
+    func choose(_ card: Card) {
         model.choose(card)
     }
 }

Memorize/EmojiMemoryGameView.swift

@@ -1,5 +1,5 @@
 //
-//  ContentView.swift
+//  EmojiMemoryGameView.swift
 //  Memorize
 //
 //  Created by ching on 2023/2/12.
@@ -7,15 +7,15 @@
 
 import SwiftUI
 
-struct ContentView: View {
+struct EmojiMemoryGameView: View {
-    @ObservedObject var viewModel: EmojiMemoryGame
+    @ObservedObject var game: EmojiMemoryGame
     var body: some View {
         ScrollView {
             LazyVGrid(columns: [GridItem(.adaptive(minimum: 65))]) {
-                ForEach(viewModel.cards) {
+                ForEach(game.cards) {
                     card in CardView(card: card).aspectRatio(2 / 3, contentMode: .fit)
                         .onTapGesture {
-                            viewModel.choose(card)
+                            game.choose(card)
                         }
                 }
             }
@@ -26,11 +26,11 @@ struct ContentView: View {
 }
 
 struct CardView: View {
-    let card: MemoryGame<String>.Card
+    let card: EmojiMemoryGame.Card
     var body: some View {
         ZStack {
             let shape = RoundedRectangle(cornerRadius: 20.0)
-            if card.isFaceUp {
+            if card.isFaceUp && !card.isMatched {
                 shape.fill().foregroundColor(.white)
                 shape.strokeBorder(lineWidth: 3)
                 Text(card.content).font(.largeTitle)
@@ -46,9 +46,9 @@ struct CardView: View {
 struct ContentView_Previews: PreviewProvider {
     static var previews: some View {
         let game = EmojiMemoryGame()
-        ContentView(viewModel: game)
+        EmojiMemoryGameView(game: game)
             .preferredColorScheme(.dark)
-        ContentView(viewModel: game)
+        EmojiMemoryGameView(game: game)
             .preferredColorScheme(.light)
     }
 }

Memorize/MemorizeApp.swift

@@ -12,7 +12,7 @@ struct MemorizeApp: App {
     let game = EmojiMemoryGame()
     var body: some Scene {
         WindowGroup {
-            ContentView(viewModel: game)
+            EmojiMemoryGameView(game: game)
         }
     }
 }

Memorize/MemoryGame.swift

@@ -10,7 +10,10 @@ import Foundation
 // model
 struct MemoryGame<CardContent> where CardContent: Equatable {
     private(set) var cards: [Card]
-    private var indexOfTheOneAndOnlyFaceUpCard: Int?
+    private var indexOfTheOneAndOnlyFaceUpCard: Int? {
+        get { cards.indices.filter { cards[$0].isFaceUp }.oneAndOnly }
+        set { cards.indices.forEach { cards[$0].isFaceUp = ($0 == newValue) } }
+    }
 
     mutating func choose(_ card: Card) {
         if let chosenIndex = cards.firstIndex(where: { $0.id == card.id }), !cards[chosenIndex].isFaceUp, !cards[chosenIndex].isMatched {
@@ -19,16 +22,10 @@ struct MemoryGame<CardContent> where CardContent: Equatable {
                     cards[chosenIndex].isMatched = true
                     cards[potentialMatchIndex].isMatched = true
                 }
-                indexOfTheOneAndOnlyFaceUpCard = nil
+                cards[chosenIndex].isFaceUp.toggle()
             } else {
-                for index in cards.indices {
-                    if cards[index].isFaceUp {
-                        cards[index].isFaceUp.toggle()
-                    }
-                }
                 indexOfTheOneAndOnlyFaceUpCard = chosenIndex
             }
-            cards[chosenIndex].isFaceUp.toggle()
         }
     }
 
@@ -42,8 +39,8 @@ struct MemoryGame<CardContent> where CardContent: Equatable {
     }
 
     init(numberOfPairsOfCards: Int, createCardContent: (Int) -> CardContent) {
-        cards = [Card]()
+        cards = []
-        //
+
         for pairIndex in 0 ..< numberOfPairsOfCards {
             let content: CardContent = createCardContent(pairIndex)
             cards.append(Card(content: content, id: pairIndex * 2))
@@ -52,9 +49,19 @@ struct MemoryGame<CardContent> where CardContent: Equatable {
     }
 
     struct Card: Identifiable {
-        var isFaceUp: Bool = false
+        var isFaceUp = false
-        var isMatched: Bool = false
+        var isMatched = false
-        var content: CardContent
+        let content: CardContent
-        var id: Int
+        let id: Int
+    }
+}
+
+extension Array {
+    var oneAndOnly: Element? {
+        if count == 1 {
+            return first
+        } else {
+            return nil
+        }
     }
 }