Incredible Flutter Location Plugin

What are Flutter Plugin?

Flutter is a wrapper for native code such as Android (Kotlin or Java) and iOS (iOS) (swift or objective c). For the plugin, we’ll need to create Android and iOS-specific code. For Android, we can use Kotlin or Java, and for iOS, we can use Swift or Objective-C.

Flutter Location Plugin

This plugin for Flutter handles getting a location on Android and iOS. It also provides callbacks when the location is changed.

Web demo (more features available on Android/iOS)

Getting Started

Add this to your package’s pubspec.yaml file:

dependencies:
  location: ^4.2.0

Android

With Flutter 1.12, all the dependencies are automatically added to your project. If your project was created before Flutter 1.12, you might need to follow this.

To use location background mode on Android, you have to use the enableBackgroundMode({bool enable}) API before accessing location in the background and adding necessary permissions. You should place the required permissions in your applications /android/app/src/main/AndroidManifest.xml:

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

Remember that the user has to accept the location permission to always allow to use the background location. The Android 11 option to always allow is not presented on the location permission dialog prompt. The user has to enable it manually from the app settings. This should be explained to the user on a separate UI that redirects the user to the app’s location settings managed by the operating system. More on that topic can be found on Android developer pages.

iOS

And to use it in iOS, you have to add this permission in Info.plist :

// This is probably the only one you need. Background location is supported
// by this -- the caveat is that a blue badge is shown in the status bar
// when the app is using location service while in the background.
NSLocationWhenInUseUsageDescription

// Deprecated, use NSLocationAlwaysAndWhenInUseUsageDescription instead.
NSLocationAlwaysUsageDescription

// Use this very carefully. This key is required only if your iOS app
// uses APIs that access the user’s location information at all times,
// even if the app isn't running.
NSLocationAlwaysAndWhenInUseUsageDescription

To receive location when application is in background, to Info.plist you have to add property list key :

UIBackgroundModes

with string value:

location

Web

Nothing to do, the plugin works directly out of box.

macOS

Ensure that the application is properly “sandboxed” and that the location is enabled. You can do this in Xcode with the following steps:

1. In the project navigator, click on your application’s target. This should bring up a view with tabs such as “General”, “Capabilities”, “Resource Tags”, etc.
2. Click on the “Capabilities” tab. This will give you a list of items such as “App Groups”, “App Sandbox”, and so on. Each item will have an “On/Off” button.
3. Turn on the “App Sandbox” item and press the “>” button on the left to show the sandbox stuff.
4. In the “App Data” section, select “Location”.

Add this permission in Info.plist :

NSLocationWhenInUseUsageDescription
NSLocationAlwaysUsageDescription

Usage

Then you just have to import the package with

import 'package:location/location.dart';

In order to request location, you should always check Location Service status and Permission status manually

Location location = new Location();

bool _serviceEnabled;
PermissionStatus _permissionGranted;
LocationData _locationData;

_serviceEnabled = await location.serviceEnabled();
if (!_serviceEnabled) {
  _serviceEnabled = await location.requestService();
  if (!_serviceEnabled) {
    return;
  }
}

_permissionGranted = await location.hasPermission();
if (_permissionGranted == PermissionStatus.denied) {
  _permissionGranted = await location.requestPermission();
  if (_permissionGranted != PermissionStatus.granted) {
    return;
  }
}

_locationData = await location.getLocation();

You can also get continuous callbacks when your position is changing:

location.onLocationChanged.listen((LocationData currentLocation) {
  // Use current location
});

To receive location when application is in background you have to enable it:

location.enableBackgroundMode(enable: true)

Be sure to check the example project to get other code samples.

On Android, a foreground notification is displayed with information that location service is running in the background.

On iOS, while the app is in the background and gets the location, the blue system bar notifies users about updates. Tapping on this bar moves the User back to the app.

Public Methods Summary

You should try to manage permission manually with requestPermission() to avoid error, but plugin will try handle some cases for you.

Objects

class LocationData {
  final double latitude; // Latitude, in degrees
  final double longitude; // Longitude, in degrees
  final double accuracy; // Estimated horizontal accuracy of this location, radial, in meters
  final double altitude; // In meters above the WGS 84 reference ellipsoid
  final double speed; // In meters/second
  final double speedAccuracy; // In meters/second, always 0 on iOS
  final double heading; // Heading is the horizontal direction of travel of this device, in degrees
  final double time; // timestamp of the LocationData
  final bool isMock; // Is the location currently mocked
}


enum LocationAccuracy {
  powerSave, // To request best accuracy possible with zero additional power consumption,
  low, // To request "city" level accuracy
  balanced, // To request "block" level accuracy
  high, // To request the most accurate locations available
  navigation // To request location for navigation usage (affect only iOS)
}

// Status of a permission request to use location services.
enum PermissionStatus {
  /// The permission to use location services has been granted.
  granted,
  // The permission to use location services has been denied by the user. May have been denied forever on iOS.
  denied,
  // The permission to use location services has been denied forever by the user. No dialog will be displayed on permission request.
  deniedForever
}

Note: you can convert the timestamp into a DateTime with: DateTime.fromMillisecondsSinceEpoch(locationData.time.toInt())

GitHub

Source Code: Flutter Location Plugin.