Antigravity で始めるwatchOS アプリ開発 — Apple Watch 向けアプリをAIエージェントで効率的に作る方法

// Antigravity に生成させた watchOS 向けリストビューの例
struct WorkoutListView: View {
    let workouts: [Workout]
 
    var body: some View {
        // watchOS では NavigationStack が使用可能（watchOS 9 以降）
        NavigationStack {
            List(workouts) { workout in
                NavigationLink(destination: WorkoutDetailView(workout: workout)) {
                    HStack {
                        Image(systemName: workout.iconName)
                            .foregroundColor(.orange)
                            .frame(width: 28, height: 28)
                        VStack(alignment: .leading, spacing: 2) {
                            Text(workout.name)
                                .font(.system(size: 15, weight: .semibold))
                            Text(workout.duration)
                                .font(.system(size: 13))
                                .foregroundColor(.secondary)
                        }
                    }
                }
            }
            .navigationTitle("ワークアウト")
        }
    }
}

struct HeartRateView: View {
    @State private var crownValue: Double = 70.0
 
    var body: some View {
        VStack {
            Text("目標心拍数")
                .font(.footnote)
                .foregroundColor(.secondary)
            Text("\(Int(crownValue))")
                .font(.system(size: 48, weight: .bold, design: .rounded))
                .foregroundColor(.red)
            Text("bpm")
                .font(.footnote)
        }
        // デジタルクラウンで値を調整
        .focusable()
        .digitalCrownRotation(
            $crownValue,
            from: 50,
            through: 200,
            by: 1,
            sensitivity: .medium
        )
    }
}
// 期待する出力: クラウンを回すと心拍数の目標値がリアルタイムで変化する

import WidgetKit
import SwiftUI
 
// Complication のエントリ（表示するデータ）
struct FitnessEntry: TimelineEntry {
    let date: Date
    let stepCount: Int
    let caloriesBurned: Double
}
 
// Complication のビュー定義
struct FitnessComplicationView: View {
    var entry: FitnessEntry
 
    var body: some View {
        VStack(alignment: .leading, spacing: 2) {
            Image(systemName: "figure.walk")
                .foregroundColor(.green)
            Text("\(entry.stepCount)")
                .font(.system(size: 14, weight: .bold))
                .minimumScaleFactor(0.7)
            Text("歩")
                .font(.system(size: 10))
                .foregroundColor(.secondary)
        }
    }
}
 
// タイムラインプロバイダ（データ更新ロジック）
struct FitnessProvider: TimelineProvider {
    func getTimeline(in context: Context, completion: @escaping (Timeline<FitnessEntry>) -> Void) {
        let entry = FitnessEntry(
            date: Date(),
            stepCount: 8432,      // 実際は HealthKit からデータ取得
            caloriesBurned: 312.5
        )
        let timeline = Timeline(entries: [entry], policy: .atEnd)
        completion(timeline)
    }
 
    func placeholder(in context: Context) -> FitnessEntry {
        FitnessEntry(date: Date(), stepCount: 0, caloriesBurned: 0)
    }
 
    func getSnapshot(in context: Context, completion: @escaping (FitnessEntry) -> Void) {
        completion(FitnessEntry(date: Date(), stepCount: 8432, caloriesBurned: 312.5))
    }
}

import HealthKit
 
class HealthKitManager: ObservableObject {
    private let healthStore = HKHealthStore()
 
    // 取得を許可するデータ型
    private let typesToRead: Set<HKObjectType> = [
        HKObjectType.quantityType(forIdentifier: .stepCount)!,
        HKObjectType.quantityType(forIdentifier: .heartRate)!,
        HKObjectType.quantityType(forIdentifier: .activeEnergyBurned)!
    ]
 
    // 権限リクエスト
    func requestAuthorization() async throws {
        guard HKHealthStore.isHealthDataAvailable() else {
            throw HealthKitError.notAvailable
        }
        try await healthStore.requestAuthorization(
            toShare: [],
            read: typesToRead
        )
    }
 
    // 今日の歩数を取得
    func fetchTodayStepCount() async -> Int {
        let type = HKQuantityType(.stepCount)
        let startOfDay = Calendar.current.startOfDay(for: Date())
        let predicate = HKQuery.predicateForSamples(
            withStart: startOfDay,
            end: Date(),
            options: .strictStartDate
        )
 
        return await withCheckedContinuation { continuation in
            let query = HKStatisticsQuery(
                quantityType: type,
                quantitySamplePredicate: predicate,
                options: .cumulativeSum
            ) { _, result, _ in
                let count = result?.sumQuantity()?.doubleValue(for: .count()) ?? 0
                continuation.resume(returning: Int(count))
            }
            self.healthStore.execute(query)
        }
    }
}
// 期待する出力: 今日の歩数が Int 型で取得できる

import WatchConnectivity
 
class WatchSessionManager: NSObject, WCSessionDelegate, ObservableObject {
    @Published var receivedData: [String: Any] = [:]
 
    override init() {
        super.init()
        if WCSession.isSupported() {
            WCSession.default.delegate = self
            WCSession.default.activate()
        }
    }
 
    // iPhone からメッセージを受信
    func session(
        _ session: WCSession,
        didReceiveMessage message: [String: Any]
    ) {
        DispatchQueue.main.async {
            self.receivedData = message
        }
    }
 
    // Watch から iPhone へメッセージを送信
    func sendToPhone(_ message: [String: Any]) {
        guard WCSession.default.isReachable else { return }
        WCSession.default.sendMessage(message, replyHandler: nil) { error in
            print("送信エラー: \(error.localizedDescription)")
        }
    }
 
    // --- WCSessionDelegate の必須メソッド ---
    func sessionDidBecomeInactive(_ session: WCSession) {}
    func sessionDidDeactivate(_ session: WCSession) {
        WCSession.default.activate()
    }
    func session(
        _ session: WCSession,
        activationDidCompleteWith activationState: WCSessionActivationState,
        error: Error?
    ) {}
}