flutter_foreground_task 8.3.1

This plugin is used to implement a foreground service on the Android platform.

example/lib/main.dart

import 'dart:async';
import 'dart:io';
import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_foreground_task/flutter_foreground_task.dart';

void main() {
  // Initialize port for communication between TaskHandler and UI.
  FlutterForegroundTask.initCommunicationPort();
  runApp(const ExampleApp());
}

// The callback function should always be a top-level function.
@pragma('vm:entry-point')
void startCallback() {
  // The setTaskHandler function must be called to handle the task in the background.
  FlutterForegroundTask.setTaskHandler(MyTaskHandler());
}

class MyTaskHandler extends TaskHandler {
  int _count = 0;

  // Called when the task is started.
  @override
  void onStart(DateTime timestamp) {
    print('onStart');
  }

  // Called every [ForegroundTaskOptions.interval] milliseconds.
  @override
  void onRepeatEvent(DateTime timestamp) {
    FlutterForegroundTask.updateService(notificationText: 'count: $_count');

    // Send data to main isolate.
    FlutterForegroundTask.sendDataToMain(_count);

    _count++;
  }

  // Called when the task is destroyed.
  @override
  void onDestroy(DateTime timestamp) {
    print('onDestroy');
  }

  // Called when data is sent using [FlutterForegroundTask.sendDataToTask].
  @override
  void onReceiveData(Object data) {
    print('onReceiveData: $data');
  }

  // Called when the notification button is pressed.
  @override
  void onNotificationButtonPressed(String id) {
    print('onNotificationButtonPressed: $id');
  }

  // Called when the notification itself is pressed.
  //
  // AOS: "android.permission.SYSTEM_ALERT_WINDOW" permission must be granted
  // for this function to be called.
  @override
  void onNotificationPressed() {
    FlutterForegroundTask.launchApp('/');
    print('onNotificationPressed');
  }

  // Called when the notification itself is dismissed.
  //
  // AOS: only work Android 14+
  // iOS: only work iOS 10+
  @override
  void onNotificationDismissed() {
    print('onNotificationDismissed');
  }
}

class ExampleApp extends StatelessWidget {
  const ExampleApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      routes: {
        '/': (context) => const ExamplePage(),
      },
      initialRoute: '/',
    );
  }
}

class ExamplePage extends StatefulWidget {
  const ExamplePage({Key? key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => _ExamplePageState();
}

class _ExamplePageState extends State<ExamplePage> {
  Future<void> _requestPermissions() async {
    // Android 13+, you need to allow notification permission to display foreground service notification.
    //
    // iOS: If you need notification, ask for permission.
    final NotificationPermission notificationPermissionStatus =
        await FlutterForegroundTask.checkNotificationPermission();
    if (notificationPermissionStatus != NotificationPermission.granted) {
      await FlutterForegroundTask.requestNotificationPermission();
    }

    if (Platform.isAndroid) {
      // "android.permission.SYSTEM_ALERT_WINDOW" permission must be granted for
      // onNotificationPressed function to be called.
      //
      // When the notification is pressed while permission is denied,
      // the onNotificationPressed function is not called and the app opens.
      //
      // If you do not use the onNotificationPressed or launchApp function,
      // you do not need to write this code.
      if (!await FlutterForegroundTask.canDrawOverlays) {
        // This function requires `android.permission.SYSTEM_ALERT_WINDOW` permission.
        await FlutterForegroundTask.openSystemAlertWindowSettings();
      }

      // Android 12+, there are restrictions on starting a foreground service.
      //
      // To restart the service on device reboot or unexpected problem, you need to allow below permission.
      if (!await FlutterForegroundTask.isIgnoringBatteryOptimizations) {
        // This function requires `android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS` permission.
        await FlutterForegroundTask.requestIgnoreBatteryOptimization();
      }
    }
  }

  Future<void> _initService() async {
    FlutterForegroundTask.init(
      androidNotificationOptions: AndroidNotificationOptions(
        channelId: 'foreground_service',
        channelName: 'Foreground Service Notification',
        channelDescription:
            'This notification appears when the foreground service is running.',
        channelImportance: NotificationChannelImportance.LOW,
        priority: NotificationPriority.LOW,
      ),
      iosNotificationOptions: const IOSNotificationOptions(
        showNotification: true,
        playSound: false,
      ),
      foregroundTaskOptions: const ForegroundTaskOptions(
        interval: 5000,
        isOnceEvent: false,
        autoRunOnBoot: true,
        autoRunOnMyPackageReplaced: true,
        allowWakeLock: true,
        allowWifiLock: true,
      ),
    );
  }

  Future<ServiceRequestResult> _startService() async {
    if (await FlutterForegroundTask.isRunningService) {
      return FlutterForegroundTask.restartService();
    } else {
      return FlutterForegroundTask.startService(
        serviceId: 256,
        notificationTitle: 'Foreground Service is running',
        notificationText: 'Tap to return to the app',
        notificationIcon: null,
        notificationButtons: [
          const NotificationButton(id: 'btn_hello', text: 'hello'),
        ],
        callback: startCallback,
      );
    }
  }

  Future<ServiceRequestResult> _stopService() async {
    return FlutterForegroundTask.stopService();
  }

  void _onReceiveTaskData(Object data) {
    if (data is int) {
      print('count: $data');
    }
  }

  void _sendRandomData() {
    final Random random = Random();
    final int data = random.nextInt(100);
    FlutterForegroundTask.sendDataToTask(data);
  }

  @override
  void initState() {
    super.initState();
    // Add a callback to receive data sent from the TaskHandler.
    FlutterForegroundTask.addTaskDataCallback(_onReceiveTaskData);

    WidgetsBinding.instance.addPostFrameCallback((_) {
      // Request permissions and initialize the service.
      _requestPermissions();
      _initService();
    });
  }

  @override
  void dispose() {
    // Remove a callback to receive data sent from the TaskHandler.
    FlutterForegroundTask.removeTaskDataCallback(_onReceiveTaskData);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // ** optional **
    // A widget that minimize the app without closing it when the user presses
    // the soft back button. It only works when the service is running.
    //
    // This widget must be declared above the [Scaffold] widget.
    return WithForegroundTask(
      child: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Foreground Task'),
          centerTitle: true,
        ),
        body: _buildContentView(),
      ),
    );
  }

  Widget _buildContentView() {
    buttonBuilder(String text, {VoidCallback? onPressed}) {
      return ElevatedButton(
        onPressed: onPressed,
        child: Text(text),
      );
    }

    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          buttonBuilder('start service', onPressed: _startService),
          buttonBuilder('stop service', onPressed: _stopService),
          buttonBuilder('send random data', onPressed: _sendRandomData),
        ],
      ),
    );
  }
}