Rorkで作ったアプリの進行状況を、ロック画面とダイナミックアイランドに出す

import ActivityKit
 
struct MeditationAttributes: ActivityAttributes {
    // 更新で書き換わる動的な状態
    public struct ContentState: Codable, Hashable {
        var remainingSeconds: Int
        var phase: String   // "breathing" / "rest" など
    }
 
    // セッション開始時に固定する静的な値
    var sessionTitle: String
    var totalSeconds: Int
}

import ActivityKit
 
final class MeditationLiveActivity {
    private var activity: Activity<MeditationAttributes>?
 
    func start(title: String, total: Int) {
        // 端末側で Live Activities が許可されているか必ず確認する
        guard ActivityAuthorizationInfo().areActivitiesEnabled else { return }
 
        let attributes = MeditationAttributes(sessionTitle: title, totalSeconds: total)
        let initial = MeditationAttributes.ContentState(
            remainingSeconds: total, phase: "breathing"
        )
 
        do {
            activity = try Activity.request(
                attributes: attributes,
                content: .init(state: initial, staleDate: nil),
                pushType: nil          // ローカル更新のみ。Push更新は後述
            )
        } catch {
            // ここは握りつぶさず、必ずログに残す
            print("Live Activity start failed: \(error)")
        }
    }
 
    func update(remaining: Int, phase: String) {
        let state = MeditationAttributes.ContentState(
            remainingSeconds: remaining, phase: phase
        )
        Task {
            await activity?.update(.init(state: state, staleDate: nil))
        }
    }
 
    func end() {
        Task {
            await activity?.end(nil, dismissalPolicy: .immediate)
        }
    }
}

import WidgetKit
import SwiftUI
 
struct MeditationWidget: Widget {
    var body: some WidgetConfiguration {
        ActivityConfiguration(for: MeditationAttributes.self) { context in
            // ロック画面・バナー表示
            VStack {
                Text(context.attributes.sessionTitle)
                Text(format(context.state.remainingSeconds))
                    .font(.system(size: 36, weight: .semibold, design: .rounded))
                    .monospacedDigit()
            }
            .padding()
        } dynamicIsland: { context in
            DynamicIsland {
                DynamicIslandExpandedRegion(.center) {
                    Text(format(context.state.remainingSeconds)).monospacedDigit()
                }
            } compactLeading: {
                Image(systemName: "leaf.fill")
            } compactTrailing: {
                Text(format(context.state.remainingSeconds)).monospacedDigit()
            } minimal: {
                Image(systemName: "leaf.fill")
            }
        }
    }
}

func cleanupStaleActivities() {
    for activity in Activity<MeditationAttributes>.activities {
        Task { await activity.end(nil, dismissalPolicy: .immediate) }
    }
}