poly_geofence_service: A Dart repository from ryonlabaw

This plugin is a service that can perform geo-fencing by creating a polygon geofence. It does not use the Geofence API implemented on the platform. Therefore, battery efficiency cannot be guaranteed. Instead, this plugin can provide more accurate and realtime geo-fencing by navigating your location while your app is alive.

Screenshots

Google Maps	Result

Features

Complex geo-fencing can be performed by creating polygon geofence.
PolyGeofenceService can perform geo-fencing in real time and catch errors during operation.
PolyGeofenceService can be operated in the background using WillStartForegroundTask widget.

Getting started

To use this plugin, add poly_geofence_service as a dependency in your pubspec.yaml file. For example:

dependencies:
  poly_geofence_service: ^1.5.8

After adding the poly_geofence_service plugin to the flutter project, we need to specify the platform-specific permissions and services to use for this plugin to work properly.

🐤 Android

Since geo-fencing operates based on location, we need to add the following permission to the AndroidManifest.xml file. Open the AndroidManifest.xml file and specify it between the <manifest> and <application> tags.

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

If you want to run the service in the background, add the following permission. If your project supports Android 10, be sure to add the ACCESS_BACKGROUND_LOCATION permission.

<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

And specify the service inside the <application> tag as follows.

<service
    android:name="com.pravera.flutter_foreground_task.service.ForegroundService"
    android:foregroundServiceType="location"
    android:stopWithTask="true" />

🐤 iOS

Like Android platform, geo-fencing is based on location, we need to add the following description. Open the ios/Runner/Info.plist file and specify it inside the <dict> tag.

<key>NSLocationWhenInUseUsageDescription</key>
<string>Used to provide geofence service.</string>

If you want to run the service in the background, add the following description.

<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>Used to provide geofence services in the background.</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>Used to provide geofence services in the background.</string>
<key>UIBackgroundModes</key>
<array>
    <string>fetch</string>
    <string>location</string>
</array>

(Optional) To display a notification when your app enters the background, you need to open the ios/Runner/AppDelegate file and set the following:

Objective-C:

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [GeneratedPluginRegistrant registerWithRegistry:self];

  // here
  if (@available(iOS 10.0, *)) {
    [UNUserNotificationCenter currentNotificationCenter].delegate = (id<UNUserNotificationCenterDelegate>) self;
  }

  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

@end

Swift:

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)

    // here
    if #available(iOS 10.0, *) {
      UNUserNotificationCenter.current().delegate = self as? UNUserNotificationCenterDelegate
    }

    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

How to use

Create a PolyGeofenceService instance and set options. PolyGeofenceService.instance.setup() provides the following options:

interval: The time interval in milliseconds to check the polygon geofence status. The default is 5000.
accuracy: Geo-fencing error range in meters. The default is 100.
loiteringDelayMs: Sets the delay between PolyGeofenceStatus.ENTER and PolyGeofenceStatus.DWELL in milliseconds. The default is 300000.
statusChangeDelayMs: Sets the status change delay in milliseconds. PolyGeofenceStatus.ENTER and PolyGeofenceStatus.EXIT events may be called frequently when the location is near the boundary of the polygon geofence. Use this option to minimize event calls at this time. If the option value is too large, realtime geo-fencing is not possible, so use it carefully. The default is 10000.
allowMockLocations: Whether to allow mock locations. The default is false.
printDevLog: Whether to show the developer log. If this value is set to true, logs for geofence service activities (start, stop, etc.) can be viewed. It does not work in release mode. The default is false.

// Create a [PolyGeofenceService] instance and set options.
final _polyGeofenceService = PolyGeofenceService.instance.setup(
    interval: 5000,
    accuracy: 100,
    loiteringDelayMs: 60000,
    statusChangeDelayMs: 10000,
    allowMockLocations: false,
    printDevLog: false);

Create a PolyGeofence list. PolyGeofence provides the following parameters:

id: Identifier for PolyGeofence.
data: Custom data for PolyGeofence.
polygon: A list of coordinates to create a polygon. The polygon is always considered closed, regardless of whether the last point equals the first or not.

// Create a [PolyGeofence] list.
final _polyGeofenceList = <PolyGeofence>[
  PolyGeofence(
    id: 'Yongdusan_Park',
    data: {
      'address': '37-55 Yongdusan-gil, Gwangbokdong 2(i)-ga, Jung-gu, Busan',
      'about': 'Mountain park known for its 129m-high observation tower, statues & stone monuments.',
    },
    polygon: <LatLng>[
      const LatLng(35.101727, 129.031665),
      const LatLng(35.101815, 129.033458),
      const LatLng(35.100032, 129.034055),
      const LatLng(35.099324, 129.033811),
      const LatLng(35.099906, 129.031927),
      const LatLng(35.101080, 129.031534),
    ],
  ),
];

// This function is to be called when the geofence status is changed.
Future<void> _onPolyGeofenceStatusChanged(
    PolyGeofence polyGeofence,
    PolyGeofenceStatus polyGeofenceStatus,
    Location location) async {
  print('polyGeofence: ${polyGeofence.toJson()}');
  print('polyGeofenceStatus: ${polyGeofenceStatus.toString()}');
}

// This function is to be called when the location has changed.
void _onLocationChanged(Location location) {
  print('location: ${location.toJson()}');
}

// This function is to be called when a location services status change occurs
// since the service was started.
void _onLocationServicesStatusChanged(bool status) {
  print('isLocationServicesEnabled: $status');
}

// This function is used to handle errors that occur in the service.
void _onError(error) {
  final errorCode = getErrorCodesFromError(error);
  if (errorCode == null) {
    print('Undefined error: $error');
    return;
  }

  print('ErrorCode: $errorCode');
}

@override
void initState() {
  super.initState();
  WidgetsBinding.instance?.addPostFrameCallback((_) {
    _polyGeofenceService.addPolyGeofenceStatusChangeListener(_onPolyGeofenceStatusChanged);
    _polyGeofenceService.addLocationChangeListener(_onLocationChanged);
    _polyGeofenceService.addLocationServicesStatusChangeListener(_onLocationServicesStatusChanged);
    _polyGeofenceService.addStreamErrorListener(_onError);
    _polyGeofenceService.start(_polyGeofenceList).catchError(_onError);
  });
}

Add WillStartForegroundTask widget for background execution on Android platform. WillStartForegroundTask provides the following options:

onWillStart: Called to ask if you want to start the foreground task.
notificationOptions: Optional values for notification detail settings.
notificationTitle: The title that will be displayed in the notification.
notificationText: The text that will be displayed in the notification.
child: A child widget that contains the Scaffold widget.

@override
Widget build(BuildContext context) {
  return MaterialApp(
    // A widget used when you want to start a foreground task when trying to minimize or close the app.
    // Declare on top of the [Scaffold] widget.
    home: WillStartForegroundTask(
      onWillStart: () async {
        // You can add a foreground task start condition.
        return _polyGeofenceService.isRunningService;
      },
      androidNotificationOptions: AndroidNotificationOptions(
        channelId: 'geofence_service_notification_channel',
        channelName: 'Geofence Service Notification',
        channelDescription: 'This notification appears when the geofence service is running in the background.',
        channelImportance: NotificationChannelImportance.LOW,
        priority: NotificationPriority.LOW,
        isSticky: false,
      ),
      iosNotificationOptions: const IOSNotificationOptions(),
      notificationTitle: 'Geofence Service is running',
      notificationText: 'Tap to return to the app',
      child: Scaffold(
        appBar: AppBar(
          title: const Text('Poly Geofence Service'),
          centerTitle: true,
        ),
        body: _buildContentView(),
      ),
    ),
  );
}

To add or remove PolyGeofence while the service is running, use the following function:

_polyGeofenceService.addPolyGeofence(Object);
_polyGeofenceService.addPolyGeofenceList(List);
_polyGeofenceService.removePolyGeofence(Object);
_polyGeofenceService.removePolyGeofenceList(List);
_polyGeofenceService.removePolyGeofenceById(String);
_polyGeofenceService.clearPolyGeofenceList();

If you want to pause or resume the service, use the function below.

_polyGeofenceService.pause();
_polyGeofenceService.resume();

When you are finished using the service, unregister the listener and call PolyGeofenceService.instance.stop().

_polyGeofenceService.removePolyGeofenceStatusChangeListener(_onPolyGeofenceStatusChanged);
_polyGeofenceService.removeLocationChangeListener(_onLocationChanged);
_polyGeofenceService.removeLocationServicesStatusChangeListener(_onLocationServicesStatusChanged);
_polyGeofenceService.removeStreamErrorListener(_onError);
_polyGeofenceService.clearAllListeners();
_polyGeofenceService.stop();

Note: When calling the stop function, the listener is not removed, but the added geofence is cleared.

Models

🐔 LatLng

A model representing the latitude and longitude of GPS.

Property	Description
`latitude`	The latitude of GPS.
`longitude`	The longitude of GPS.

🐔 PolyGeofence

A model representing a polygon geofence.

Property	Description
`id`	Identifier for `PolyGeofence`.
`data`	Custom data for `PolyGeofence`.
`polygon`	A list of coordinates to create a polygon. The polygon is always considered closed, regardless of whether the last point equals the first or not.
`status`	The status of `PolyGeofence`.
`timestamp`	The timestamp when polygon geofence status changes.

🐔 PolyGeofenceStatus

Defines the status of the polygon geofence.

Value	Description
`ENTER`	Occurs when entering the geofence area.
`EXIT`	Occurs when exiting the geofence area.
`DWELL`	Occurs when the loitering delay elapses after entering the geofence area.

🐔 ErrorCodes

Error codes that may occur in the service.

Value	Description
`ALREADY_STARTED`	Occurs when the service has already been started but the start function is called.
`LOCATION_SERVICES_DISABLED`	Occurs when location services are disabled. When this error occurs, you should notify the user and request activation.
`LOCATION_PERMISSION_DENIED`	Occurs when location permission is denied.
`LOCATION_PERMISSION_PERMANENTLY_DENIED`	Occurs when location permission is permanently denied. In this case, the user must manually allow the permission.

Support

If you find any bugs or issues while using the plugin, please register an issues on GitHub. You can also contact us at hwj930513@naver.com.

ryonlabaw/poly_geofence_service