Long Polling Stream and Need to Cancel Timer

polling.dart

// The focus on/off methods fire.  I am not sure how to change the providers so that I can either force dispose or just start/stop the timer?

final MyRequestProvider =
    StreamProvider.autoDispose<List<MyRequest>>((ref) {
  StreamController<List<MyRequest>> controller =
      StreamController<List<MyRequest>>();

  ClientResolver clientResolver = ClientResolver();

  IServiceClient client = clientResolver.getClient(AppParameters.getBaseUrl());
  PendingMy apiRequest = PendingMy();
 
  Timer timer = Timer.periodic(Duration(seconds: 10), (t) {
     client.get(apiRequest).then((data) { 
      controller.add(data.results);
    });
  });

  ref.onDispose(() {
    if (timer != null && timer.isActive) {
      timer.cancel();
    }
    controller.close();
  });

  return controller.stream;
});

// using the https://pub.dev/packages/focus_detector to detect screen on / off
// how do i control the timer and polling in this case?

// somewhere in a build tree:

FocusDetector(
      key: _focusDetectorKey,
      onFocusGained: () {
       
      },
      onFocusLost: () {
        debugPrint('CharacterListPage lost focus');
        var d = context.read(curbsideRequestProvider);
       // d.dispose()?
      }_
  )