CODEWITHSUNDEEP
flutterdart
Kris
Kris

Reputation: 3361

Measuring amount of time the app has been open

I am trying to trigger an event after the app is open for ten minutes. Is there an easy way to do this? I imagine I need to start a timer when the app is first built, but then be able to cancel or pause that timer if the user navigates away from the app somehow.

I have found the screen state library, but that library only listens for the screen turning off and on, and not for events like navigating home or to another app. I'm familiar with WillPopScope, and related to that I found back button interceptor, but my understanding is that only intercepts when the user presses the back button, and not if the user presses home or switches to another app.

Is there some central way for listening to anything that will close or navigate away from the app, or a combination of things to listen to?

Upvotes: 0

Views: 1021

Answers (1)

Abion47
Abion47

Reputation: 24671

Start a Timer when your main method runs:

import 'dart:async';

void main() {
  Timer(Duration(minutes: 10), () {
    // Handle the event
  });

  runApp(MyApp());
}

If you want to be able to control the timer, set it up in your root widget and have that widget listen to lifecycle events:

class MyApp extends StatefulWidget {
  ...
}

class MyAppState extends State<MyApp> with WidgetsBindingObserver {
  static const _appTimerDuration = const Duration(minutes: 10);
  Timer appTimer;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    appTimer = Timer(_appTimerDuration, _timerElapsed);
  }

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

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed) {
      appTimer = Timer(_appTimerDuration, _timerElapsed);
    } else {
      appTimer?.cancel();
    }
  }

  void _timerElapsed() {
    // Handle the event
  }

  ...
}

Upvotes: 1

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