Flutter - How to hide or change widget as seen in Recent Apps overview

Question

I'm developing a Flutter application that deals with cryptocurrency (a wallet). Some people have requested that the app takes some measures to hide their balance, etc.

The one thing I can't figure out, however, is hiding information from the recent apps menu (like secure window mode on Android, or simply changing the interface so balance isn't visible.)

I added a WidgetsBindingObserver to my main widget and tried something like:

@override
void didChangeAppLifecycleState(AppLifecycleState state) {
  switch (state) {
    case AppLifecycleState.paused:
      setState(() {
          _hideBalance = true;
      });
      super.didChangeAppLifecycleState(state);
      break;
    case AppLifecycleState.resumed:
      setState(() {
          _hideBalance = false;
      });
      super.didChangeAppLifecycleState(state);
      break;
    default:
      super.didChangeAppLifecycleState(state);
      break;
  }
}

@override
void initState() {
   super.initState();
   WidgetsBinding.instance.addObserver(this);
}

@override
void dispose() {
   WidgetsBinding.instance.removeObserver(this);
   super.dispose();
}

@override
Widget build(BuildContext context) {
    return _hideBalance ? SizedBox() : Text("$12,234");
}

However, this has no effect on the recent apps which appears to be an exact snapshot from the moment the home button was pressed (on my OnePlus 6T at least). E.g. - I can still see the balance in the recent apps/app switcher overview.

Is there a way to do this with flutter?

Answer 1

Are you saying this function is not called? If yes, you need to add the following,

@override
void initState() {
   super.initState();
   WidgetsBinding.instance.addObserver(this);
}

@override
void dispose() {
   WidgetsBinding.instance.removeObserver(this);
   super.dispose();
}