fl_location 5.0.0

A plugin that can access the location services of each platform and collect device location data.

example/lib/main.dart

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

import 'package:fl_location/fl_location.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main() => runApp(ExampleApp());

enum ButtonState { LOADING, DONE, DISABLED }

class ExampleApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _ExampleAppState();
}

class _ExampleAppState extends State<ExampleApp> {
  StreamSubscription<Location>? _locationSubscription;

  final _resultText = ValueNotifier('');
  final _getLocationButtonState = ValueNotifier(ButtonState.DONE);
  final _subscribeLocationStreamButtonState = ValueNotifier(ButtonState.DONE);
  final _isSubscribeLocationStream = ValueNotifier(false);

  Future<bool> _requestLocationPermission({bool background = false}) async {
    if (!await FlLocation.isLocationServicesEnabled) {
      _resultText.value = 'Location services is disabled.';
      return false;
    }

    LocationPermission permission = await FlLocation.checkLocationPermission();
    if (permission == LocationPermission.denied) {
      // Android: ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION
      // iOS 12-: NSLocationWhenInUseUsageDescription or NSLocationAlwaysAndWhenInUseUsageDescription
      // iOS 13+: NSLocationWhenInUseUsageDescription
      permission = await FlLocation.requestLocationPermission();
    }

    if (permission == LocationPermission.denied ||
        permission == LocationPermission.deniedForever) {
      _resultText.value = 'Location permission has been ${permission.name}.';
      return false;
    }

    // Web: Only allow whileInUse permission.
    if (kIsWeb || kIsWasm) {
      return true;
    }

    // Android: You must request location permission one more time to access background location.
    // iOS 12-: You can request always permission through the above request.
    // iOS 13+: You can only request whileInUse permission. When the app enters the background,
    // a prompt will appear asking for always permission.
    if (Platform.isAndroid &&
        background &&
        permission == LocationPermission.whileInUse) {
      // You need a clear explanation of why your app's feature needs access to background location.
      // https://developer.android.com/develop/sensors-and-location/location/permissions#request-background-location

      // Android: ACCESS_BACKGROUND_LOCATION
      permission = await FlLocation.requestLocationPermission();

      if (permission != LocationPermission.always) {
        _resultText.value =
            'Location permission must always be granted to collect location in the background.';
        return false;
      }
    }

    return true;
  }

  Future<void> _getLocation() async {
    if (await _requestLocationPermission()) {
      _getLocationButtonState.value = ButtonState.LOADING;
      _subscribeLocationStreamButtonState.value = ButtonState.DISABLED;

      final Duration timeLimit = const Duration(seconds: 10);
      await FlLocation.getLocation(timeLimit: timeLimit).then((location) {
        _onLocation(location);
      }).onError((error, stackTrace) {
        _onError(error);
      }).whenComplete(() {
        _getLocationButtonState.value = ButtonState.DONE;
        _subscribeLocationStreamButtonState.value = ButtonState.DONE;
      });
    }
  }

  Future<void> _subscribeLocationStream() async {
    if (await _requestLocationPermission()) {
      if (_locationSubscription != null) {
        await _unsubscribeLocationStream();
      }

      _locationSubscription = FlLocation.getLocationStream()
          .handleError(_onError)
          .listen(_onLocation);

      _getLocationButtonState.value = ButtonState.DISABLED;
      _isSubscribeLocationStream.value = true;
    }
  }

  Future<void> _unsubscribeLocationStream() async {
    await _locationSubscription?.cancel();
    _locationSubscription = null;

    _getLocationButtonState.value = ButtonState.DONE;
    _isSubscribeLocationStream.value = false;
  }

  void _onLocation(Location location) {
    _resultText.value = location.toJson().toString();
  }

  void _onError(dynamic error) {
    _resultText.value = error.toString();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Flutter Location'),
          centerTitle: true,
        ),
        body: _buildContentView(),
      ),
    );
  }

  Widget _buildContentView() {
    final Widget buttonWidget = Column(
      children: [
        const SizedBox(height: 8.0),
        ValueListenableBuilder(
          valueListenable: _getLocationButtonState,
          builder: (context, state, _) {
            return _buildTestButton(
              text: 'GET Location',
              state: state,
              onPressed: _getLocation,
            );
          },
        ),
        const SizedBox(height: 8.0),
        ValueListenableBuilder(
          valueListenable: _subscribeLocationStreamButtonState,
          builder: (context, state, _) {
            return ValueListenableBuilder(
              valueListenable: _isSubscribeLocationStream,
              builder: (context, isSubscribe, __) {
                final String text;
                final VoidCallback? onPressed;
                if (isSubscribe) {
                  text = 'Unsubscribe LocationStream';
                  onPressed = _unsubscribeLocationStream;
                } else {
                  text = 'Subscribe LocationStream';
                  onPressed = _subscribeLocationStream;
                }

                return _buildTestButton(
                  text: text,
                  state: state,
                  onPressed: onPressed,
                );
              },
            );
          },
        ),
      ],
    );

    final Widget resultWidget = ValueListenableBuilder(
      valueListenable: _resultText,
      builder: (context, resultText, _) {
        return Text(resultText);
      },
    );

    return ListView(
      padding: const EdgeInsets.symmetric(horizontal: 10.0),
      children: [
        buttonWidget,
        const SizedBox(height: 10.0),
        resultWidget,
      ],
    );
  }

  Widget _buildTestButton({
    required String text,
    required ButtonState state,
    VoidCallback? onPressed,
  }) {
    return ElevatedButton(
      child: (state == ButtonState.LOADING)
          ? SizedBox.fromSize(
              size: const Size.square(20.0),
              child: const CircularProgressIndicator(strokeWidth: 2.0))
          : Text(text),
      onPressed: (state == ButtonState.DONE) ? onPressed : null,
    );
  }

  @override
  void dispose() {
    _locationSubscription?.cancel();
    _resultText.dispose();
    _getLocationButtonState.dispose();
    _subscribeLocationStreamButtonState.dispose();
    _isSubscribeLocationStream.dispose();
    super.dispose();
  }
}