carp_background_location 3.0.1

A location plugin that works in the background. Supports Android and iOS

example/lib/main.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:carp_background_location/carp_background_location.dart';

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

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

enum LocationStatus { UNKNOWN, INITIALIZED, RUNNING, STOPPED }

String dtoToString(LocationDto dto) =>
    'Location ${dto.latitude}, ${dto.longitude} at ${DateTime.fromMillisecondsSinceEpoch(dto.time ~/ 1)}';

Widget dtoWidget(LocationDto? dto) {
  if (dto == null)
    return Text("No location yet");
  else
    return Column(
      children: <Widget>[
        Text(
          '${dto.latitude}, ${dto.longitude}',
        ),
        Text(
          '@',
        ),
        Text('${DateTime.fromMillisecondsSinceEpoch(dto.time ~/ 1)}')
      ],
    );
}

class _MyAppState extends State<MyApp> {
  String logStr = '';
  LocationDto? lastLocation;
  DateTime? lastTimeLocation;
  Stream<LocationDto>? locationStream;
  StreamSubscription<LocationDto>? locationSubscription;
  LocationStatus _status = LocationStatus.UNKNOWN;

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

    LocationManager().interval = 1;
    LocationManager().distanceFilter = 0;
    LocationManager().notificationTitle = 'CARP Location Example';
    LocationManager().notificationMsg = 'CARP is tracking your location';
    locationStream = LocationManager().locationStream;

    _status = LocationStatus.INITIALIZED;
  }

  void getCurrentLocation() async =>
      onData(await LocationManager().getCurrentLocation());

  void onData(LocationDto dto) {
    // print(dtoToString(dto));
    print(dto);
    setState(() {
      lastLocation = dto;
      lastTimeLocation = DateTime.now();
    });
  }

  /// Is "location always" permission granted?
  Future<bool> isLocationAlwaysGranted() async =>
      await Permission.locationAlways.isGranted;

  /// Tries to ask for "location always" permissions from the user.
  /// Returns `true` if successful, `false` othervise.
  Future<bool> askForLocationAlwaysPermission() async {
    bool granted = await Permission.locationAlways.isGranted;

    if (!granted) {
      granted =
          await Permission.locationAlways.request() == PermissionStatus.granted;
    }

    return granted;
  }

  /// Start listening to location events.
  void start() async {
    // ask for location permissions, if not already granted
    if (!await isLocationAlwaysGranted())
      await askForLocationAlwaysPermission();

    locationSubscription?.cancel();
    locationSubscription = locationStream?.listen(onData);
    await LocationManager().start();
    setState(() {
      _status = LocationStatus.RUNNING;
    });
  }

  void stop() {
    locationSubscription?.cancel();
    LocationManager().stop();
    setState(() {
      _status = LocationStatus.STOPPED;
    });
  }

  Widget stopButton() => SizedBox(
        width: double.maxFinite,
        child: ElevatedButton(
          child: const Text('STOP'),
          onPressed: stop,
        ),
      );

  Widget startButton() => SizedBox(
        width: double.maxFinite,
        child: ElevatedButton(
          child: const Text('START'),
          onPressed: start,
        ),
      );

  Widget status() => Text("Status: ${_status.toString().split('.').last}");

  Widget lastLoc() => Text(
      lastLocation != null
          ? dtoToString(lastLocation!)
          : 'Unknown last location',
      textAlign: TextAlign.center);

  Widget currentLocationButton() => SizedBox(
        width: double.maxFinite,
        child: ElevatedButton(
          child: const Text('CURRENT LOCATION'),
          onPressed: getCurrentLocation,
        ),
      );

  @override
  void dispose() => super.dispose();

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('CARP Background Location'),
        ),
        body: Container(
          width: double.maxFinite,
          padding: const EdgeInsets.all(22),
          child: SingleChildScrollView(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
                startButton(),
                stopButton(),
                currentLocationButton(),
                Divider(),
                status(),
                Divider(),
                dtoWidget(lastLocation),
              ],
            ),
          ),
        ),
      ),
    );
  }
}