Flutter Geofence

A Flutter geofencing plugin for Flutter applications (Android & iOS) which provides geofencing functionalities.

Features

• Geofence event triggered on location changes
• Get continuous geofence event updates

Usage

To add the geofence_flutter to your Flutter application, follow the installation instructions. Below are some Android and iOS specifics that are required for the geofence_flutter to work correctly.

For Android

AndroidX

The geofence_flutter plugin requires the AndroidX version of the Android Support Libraries. This means you need to make sure your Android project supports AndroidX. Detailed instructions can be found here.

The TL;DR version is:

1. Add the following to your gradle.properties file:

   android.useAndroidX=true
   android.enableJetifier=true
   

2. Make sure you set the compileSdkVersion in your android/app/build.gradle file to 33:

   android {
     compileSdkVersion 33
   
     ...
   }
   

3. Make sure you replace all the android. dependencies to their AndroidX counterparts (a full list can be found here: https://developer.android.com/jetpack/androidx/migrate).

Permissions

On Android, you’ll need to add either the ACCESS_COARSE_LOCATION or the ACCESS_FINE_LOCATION permission to your Android Manifest. To do so, open the AndroidManifest.xml file (located under android/app/src/main) and add one of the following two lines as direct children of the <manifest> tag (when you configure both permissions, the ACCESS_FINE_LOCATION will be used):

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

Starting from Android 10, you need to add the ACCESS_BACKGROUND_LOCATION permission (next to the ACCESS_COARSE_LOCATION or the ACCESS_FINE_LOCATION permission) if you want to continue receiving updates even when your App is running in the background (note that the geofence_flutter plugin doesn’t support receiving and processing geofence event updates while running in the background):

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

For iOS

On iOS, you’ll need to add the following entries to your Info.plist file (located under ios/Runner) in order to access the device’s location. Simply open your Info.plist file and add the following:

<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs access to location when open.</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>This app needs access to location when in the background.</string>

If you would like to receive updates when your App is in the background, you’ll also need to add the Background Modes capability to your XCode project (Project > Signing and Capabilities > “+ Capability” button) and select Location Updates. Be careful with this, you will need to explain in detail to Apple why your App needs this when submitting your App to the AppStore. If Apple isn’t satisfied with the explanation, your App will be rejected.

API

Start Geofence Service

At first, you need to start the geofence service and for that, you need to pass the following parameters:

• pointedLatitude: the latitude of the geofence area center
• pointedLongitude: the longitude of the geofence area center
• radiusMeter: the radius of the geofence area in meters
• eventPeriodInSeconds: geofence event stream period in seconds

import 'package:geofence_flutter/geofence_flutter.dart';

await Geofence.startGeofenceService(
    pointedLatitude: "52.2165157",
    pointedLongitude: "6.9437819",
    radiusMeter: "50.0",
    eventPeriodInSeconds: 10
);

Get Geofence Event Streams

To get the stream geofence event updates on location changes, you need to subscribe to getGeofenceStream to listen to geofence event streams on current location updates.

import 'package:geofence_flutter/geofence_flutter.dart';

StreamSubscription<GeofenceEvent> geofenceEventStream = Geofence.getGeofenceStream()?.listen(
  (GeofenceEvent event) {
    print(event.toString());
});

Stop Geofence Service

To stop the geofence service, you need to specify this:

import 'package:geofence_flutter/geofence_flutter.dart';

Geofence.stopGeofenceService();

Also, stop the GeofenceEvent stream subscription listener which is geofenceEventStream in our case:

geofenceEventStream?.cancel();

Issues

Please file any issues, bugs, or feature requests as an issue on our GitHub page.

Dependencies

This plugin is dependent on the geolocator plugin of baseflow.com.

Want to Contribute

If you would like to contribute to the plugin (e.g., by improving the documentation, solving a bug, or adding a cool new feature), feel free to send your pull request.

Author

This geofence_flutter plugin for Flutter is developed by Sarfaraz.

Example Code

Here is a complete example of how to use the geofence_flutter plugin in a Flutter application:

import 'dart:async';

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Geofence',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Geofence'),
      debugShowCheckedModeBanner: false,
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  StreamSubscription<GeofenceEvent>? geofenceEventStream;
  String geofenceEvent = '';

  TextEditingController latitudeController = TextEditingController();
  TextEditingController longitudeController = TextEditingController();
  TextEditingController radiusController = TextEditingController();

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Padding(
        padding: const EdgeInsets.all(10.0),
        child: Column(
          children: [
            Text(
              "Geofence Event: $geofenceEvent",
            ),
            TextField(
              controller: latitudeController,
              decoration: InputDecoration(
                  border: InputBorder.none, hintText: 'Enter pointed latitude'),
            ),
            TextField(
              controller: longitudeController,
              decoration: InputDecoration(
                  border: InputBorder.none, hintText: 'Enter pointed longitude'),
            ),
            TextField(
              controller: radiusController,
              decoration: InputDecoration(
                  border: InputBorder.none, hintText: 'Enter radius meter'),
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                TextButton(
                  child: Text("Start"),
                  onPressed: () async {
                    await Geofence.startGeofenceService(
                        pointedLatitude: latitudeController.text,
                        pointedLongitude: longitudeController.text,
                        radiusMeter: radiusController.text,
                        eventPeriodInSeconds: 10);
                    if (geofenceEventStream == null) {
                      geofenceEventStream = Geofence.getGeofenceStream()
                          ?.listen((GeofenceEvent event) {
                        setState(() {
                          geofenceEvent = event.toString();
                        });
                      });
                    }
                  },
                ),
                SizedBox(width: 10.0),
                TextButton(
                  child: Text("Stop"),
                  onPressed: () {
                    Geofence.stopGeofenceService();
                    geofenceEventStream?.cancel();
                  },
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  @override
  void dispose() {
    latitudeController.dispose();
    longitudeController.dispose();
    radiusController.dispose();
    super.dispose();
  }
}

This example demonstrates how to start and stop the geofence service, as well as how to listen to geofence events and update the UI accordingly.