Detect when we moved back to previous page in Flutter

Question

We moved from Page1 to Page2 but now from Page2 we move back again to Page1 like this:

Navigator.of(context).pop();

How can we detect on Page1 that we went back?

Answer 1

Navigator.push(
    context,
    MaterialPageRoute(
      builder: (context) => NextPage(),
    ),
  ).then((_){
// Here you will get callback after coming back from NextPage()
// Do your code here
});

Answer 2

In your Page1, When you push Page2 wait for it to pop

Future<void> _goToPage2() async {
  await Navigator.push(
    context,
    MaterialPageRoute(
      builder: (context) => Page2(),
    ),
  );
  print("Page2 is popped");
}

Answer 3

Another solution, which is more verbose but also more efficient if you push a lot of Routes from the same Widget, would be to create your own NavigatorObserver.

1- Create your NavigatorObserver

final routeObserver = MyRouteObserver();

class MyRouteObserver extends NavigatorObserver {
  final Set<RouteAware> _listeners = <RouteAware>{};

  void subscribe(RouteAware routeAware) {
    _listeners.add(routeAware);
  }

  void unsubscribe(RouteAware routeAware) {
    _listeners.remove(routeAware);
  }

  @override
  void didPop(Route<dynamic> route, Route<dynamic>? previousRoute) {
    for (var listener in _listeners) {
      listener.didPop();
    }
  }
}

2- Add it to your MaterialApp

  return MaterialApp(
      navigatorObservers: [routeObserver],
...

3- Implement RouteAware in the Widget where you want to listen to Navigation events, and subscribe/unsubscribe to your routeObserver

class _TablePageState extends State<TablePage> implements RouteAware {

  @override
  void initState() {
    super.initState();
    routeObserver.subscribe(this);
  }


  @override
  Widget build(BuildContext context) {
    return Container();
  }

  @override
  void dispose() {
    routeObserver.unsubscribe(this);
    super.dispose();
  }

  @override
  void didPop() {
    //This method will be called from your observer
  }

  @override
  void didPopNext() {}

  @override
  void didPush() {}

  @override
  void didPushNext() {}
}