import 'package:flutter/material.dart'; class AppLifecycleLockObserver extends WidgetsBindingObserver { final VoidCallback onLock; AppLifecycleLockObserver({required this.onLock}); @override void didChangeAppLifecycleState(AppLifecycleState state) { switch (state) { case AppLifecycleState.inactive: case AppLifecycleState.hidden: case AppLifecycleState.paused: case AppLifecycleState.detached: onLock(); case AppLifecycleState.resumed: break; } } }