Recovery App from Background

recovery_service.dart

import 'package:project/core/constants/route_paths.dart' as routes;
import 'package:project/core/services/navigation_service.dart';
import 'package:project/core/services/stoppable_service.dart';
import 'package:project/core/utils/localization_keys.dart';
import 'package:project/locator.dart';

class RecoveryService extends StoppableService {
  final _navigationService = locator<NavigationService>();
  
  Duration appInBackground;

  @override
  void resume() {
    appInBackground = DateTime.now().difference(pausedAt);
    if (appInBackground.inMinutes > 5) {
      _navigationService.navigateTo(
        routes.LoadingRoute, arguments: LocalizationKeys.loading
      );
    }
    super.resume();
  }

  @override
  void pause() {
    super.pause();
  }
}

recovery_view.dart

import 'package:flutter/material.dart';
import 'package:project/core/viewmodels/recovery_view_model.dart';
import 'package:project/ui/views/base_view.dart';
import 'package:project/ui/widgets/custom_stack.dart';
import 'package:project/ui/widgets/loading_card.dart';

class RecoveryView extends StatelessWidget {
  final String message;

  const RecoveryView({
    Key key,
    this.message
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BaseView<RecoveryViewModel>(
      onModelReady: (vm) => vm.runTasks(),
      builder: (context, vm, child) {
        return CustomStack(
          child: LoadingCard(
            message: message
          ),
        );
      }
    );
  }
}

recovery_view_model.dart

import 'dart:async';

import 'package:project/core/services/authentication_service.dart';
import 'package:project/core/services/posts_service.dart';
import 'package:project/core/services/events_service.dart';
import 'package:project/core/services/navigation_service.dart';
import 'package:project/core/viewmodels/base_model.dart';
import 'package:project/locator.dart';

class RecoveryViewModel extends BaseModel {
  final _authService = locator<AuthenticationService>();
  final _postsService = locator<PostsService>();
  final _eventsService = locator<EventsService>();
  final _navigationService = locator<NavigationService>();

  String _taskInformation;
  String get taskInformation => _taskInformation;

  Future<void> runTasks() async {
    await _authService.refreshSession();
    await Future.wait([
      _postsService.fetchAll(),
      _eventsService.fetchAll()
    ]);

    _navigationService.goBack();
  }
}

stoppable_service.dart

import 'package:flutter/material.dart';

/// Abstract class that defines a stoppable service
///   - Stoppable service must be able to deactive
///   - Stoppable service must be able to pause
///   - Stoppable service must be able to resume
///   - Stoppable service must be able to suspend
abstract class StoppableService {
  bool _serviceStoped = false;
  bool get serviceStopped => _serviceStoped;
  DateTime _pausedAt;
  DateTime get pausedAt => _pausedAt;

  @mustCallSuper
  void pause() {
    _serviceStoped = true;
    _pausedAt = new DateTime.now();
  }

  @mustCallSuper
  void inactive() {
    _serviceStoped = true;
  }

  @mustCallSuper
  void resume() {
    _serviceStoped = false;
  }

  @mustCallSuper
  void suspending() {
    _serviceStoped = true;
  }
}