flutter_foreground_task 7.1.0

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

example/lib/main.dart

import 'dart:io';
import 'dart:isolate';

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

void main() => 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, SendPort? sendPort) async {
    // You can use the getData function to get the stored data.
    final customData =
        await FlutterForegroundTask.getData<String>(key: 'customData');
    print('customData: $customData');
  }

  // Called every [interval] milliseconds in [ForegroundTaskOptions].
  @override
  void onRepeatEvent(DateTime timestamp, SendPort? sendPort) async {
    FlutterForegroundTask.updateService(
      notificationTitle: 'MyTaskHandler',
      notificationText: 'count: $_count',
    );

    // Send data to the main isolate.
    sendPort?.send(_count);

    _count++;
  }

  // Called when the notification button on the Android platform is pressed.
  @override
  void onDestroy(DateTime timestamp, SendPort? sendPort) async {
    print('onDestroy');
  }

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

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

  // Called when the notification itself on the Android platform is dismissed on Android 14 which allow this behaviour.
  @override
  void onNotificationDismissed() {
    print('onNotificationDismissed');
  }
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: ExamplePage(),
    );
  }
}

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

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

class _ExamplePageState extends State<ExamplePage> {
  ReceivePort? _receivePort;

  Future<void> _requestPermissionForAndroid() async {
    if (!Platform.isAndroid) {
      return;
    }

    // "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 or higher, 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();
    }

    // Android 13 and higher, you need to allow notification permission to expose foreground service notification.
    final NotificationPermission notificationPermissionStatus =
        await FlutterForegroundTask.checkNotificationPermission();
    if (notificationPermissionStatus != NotificationPermission.granted) {
      await FlutterForegroundTask.requestNotificationPermission();
    }
  }

  void _initForegroundTask() {
    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(),
      foregroundTaskOptions: const ForegroundTaskOptions(
        interval: 5000,
        isOnceEvent: false,
        autoRunOnBoot: true,
        autoRunOnMyPackageReplaced: true,
        allowWakeLock: true,
        allowWifiLock: true,
      ),
    );
  }

  Future<bool> _startForegroundTask() async {
    // You can save data using the saveData function.
    await FlutterForegroundTask.saveData(key: 'customData', value: 'hello');

    // Register the receivePort before starting the service.
    final ReceivePort? receivePort = FlutterForegroundTask.receivePort;
    final bool isRegistered = _registerReceivePort(receivePort);
    if (!isRegistered) {
      print('Failed to register receivePort!');
      return false;
    }

    if (await FlutterForegroundTask.isRunningService) {
      return FlutterForegroundTask.restartService();
    } else {
      return FlutterForegroundTask.startService(
        notificationTitle: 'Foreground Service is running',
        notificationText: 'Tap to return to the app',
        notificationIcon: null,
        notificationButtons: [
          const NotificationButton(
            id: 'btn_hello',
            text: 'hello',
            textColor: Colors.orange,
          ),
        ],
        callback: startCallback,
      );
    }
  }

  Future<bool> _stopForegroundTask() {
    return FlutterForegroundTask.stopService();
  }

  bool _registerReceivePort(ReceivePort? newReceivePort) {
    if (newReceivePort == null) {
      return false;
    }

    _closeReceivePort();

    _receivePort = newReceivePort;
    _receivePort?.listen((data) {
      if (data is int) {
        print('count: $data');
      } else if (data is DateTime) {
        print('timestamp: ${data.toString()}');
      }
    });

    return _receivePort != null;
  }

  void _closeReceivePort() {
    _receivePort?.close();
    _receivePort = null;
  }

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      await _requestPermissionForAndroid();
      _initForegroundTask();

      // You can get the previous ReceivePort without restarting the service.
      if (await FlutterForegroundTask.isRunningService) {
        final newReceivePort = FlutterForegroundTask.receivePort;
        _registerReceivePort(newReceivePort);
      }
    });
  }

  @override
  void dispose() {
    _closeReceivePort();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // A widget that prevents the app from closing when the foreground 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', onPressed: _startForegroundTask),
          buttonBuilder('stop', onPressed: _stopForegroundTask),
        ],
      ),
    );
  }
}