Detect user killing the app from foreground

UserFromForegroundKillApp.swift

//
//  UserFromForegroundKillApp.swift
//  UserFromForegroundKill
//
//  Created by f h on 12/03/2024.
//

import SwiftUI

@main
struct UserFromForegroundKillApp: App {
  @UIApplicationDelegateAdaptor private var appDelegate: MyAppDelegate

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

final class MyAppDelegate: NSObject, UIApplicationDelegate {
  var lastEnteredBackgroundDate: Date? = nil
  let nc = NotificationCenter.default
  var subs = [NSObjectProtocol]()

  override init() {
    super.init()

    subs.append(nc.addObserver(forName: UIApplication.willResignActiveNotification, object: nil, queue: nil) {  notification in
      self.lastEnteredBackgroundDate = .now
      print("willResignActiveNotification")
    })
  }

  func applicationWillTerminate(_ application: UIApplication) {
    print("terminated")
    if let lastEnteredBackgroundDate, Date.now.timeIntervalSince1970 - lastEnteredBackgroundDate.timeIntervalSince1970 < 2 {
      print("by user")
    }
  }
}