Flutter Background Geolocation hello_world.dart https://shop.transistorsoft.com/blogs/news

flutter_background_geolocation_helloworld.dart

/**
* flutter_background_geolocation Hello World
* https://github.com/transistorsoft/flutter_background_geolocation
*/

import 'package:flutter/material.dart';
import 'package:flutter_background_geolocation/flutter_background_geolocation.dart' as bg;

////
// For pretty-printing location JSON.  Not a requirement of flutter_background_geolocation
//
import 'dart:convert';
JsonEncoder encoder = new JsonEncoder.withIndent("     ");
//
////

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'BackgroundGeolocation Demo',
      theme: new ThemeData(
        primarySwatch: Colors.amber,
      ),
      home: new MyHomePage(title: 'BackgroundGeolocation Demo'),
    );
  }
}

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

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  bool _isMoving;
  bool _enabled;
  String _motionActivity;
  String _odometer;
  String _content;

  @override
  void initState() {
    _isMoving = false;
    _enabled = false;
    _content = '';
    _motionActivity = 'UNKNOWN';
    _odometer = '0';

    // 1.  Listen to events (See docs for all 12 available events).
    bg.BackgroundGeolocation.onLocation(_onLocation);
    bg.BackgroundGeolocation.onMotionChange(_onMotionChange);
    bg.BackgroundGeolocation.onActivityChange(_onActivityChange);
    bg.BackgroundGeolocation.onProviderChange(_onProviderChange);
    bg.BackgroundGeolocation.onConnectivityChange(_onConnectivityChange);

    // 2.  Configure the plugin
    bg.BackgroundGeolocation.ready(bg.Config(
        desiredAccuracy: bg.Config.DESIRED_ACCURACY_HIGH,
        distanceFilter: 10.0,
        stopOnTerminate: false,
        startOnBoot: true,
        debug: true,
        logLevel: bg.Config.LOG_LEVEL_VERBOSE,
        reset: true
    )).then((bg.State state) {
      setState(() {
        _enabled = state.enabled;
        _isMoving = state.isMoving;
      });
    });
  }

  void _onClickEnable(enabled) {
    if (enabled) {
      bg.BackgroundGeolocation.start().then((bg.State state) {
        print('[start] success $state');
        setState(() {
          _enabled = state.enabled;
          _isMoving = state.isMoving;
        });
      });
    } else {
      bg.BackgroundGeolocation.stop().then((bg.State state) {
        print('[stop] success: $state');
        // Reset odometer.
        bg.BackgroundGeolocation.setOdometer(0.0);

        setState(() {
          _odometer = '0.0';
          _enabled = state.enabled;
          _isMoving = state.isMoving;
        });
      });
    }
  }

  // Manually toggle the tracking state:  moving vs stationary
  void _onClickChangePace() {
    setState(() {
      _isMoving = !_isMoving;
    });
    print("[onClickChangePace] -> $_isMoving");

    bg.BackgroundGeolocation.changePace(_isMoving).then((bool isMoving) {
      print('[changePace] success $isMoving');
    }).catchError((e) {
      print('[changePace] ERROR: ' + e.code.toString());
    });
  }

  // Manually fetch the current position.
  void _onClickGetCurrentPosition() {
    bg.BackgroundGeolocation.getCurrentPosition(
        persist: false,     // <-- do not persist this location
        desiredAccuracy: 0, // <-- desire best possible accuracy
        timeout: 30000,     // <-- wait 30s before giving up.
        samples: 3          // <-- sample 3 location before selecting best.
    ).then((bg.Location location) {
      print('[getCurrentPosition] - $location');
    }).catchError((error) {
      print('[getCurrentPosition] ERROR: $error');
    });
  }

  ////
  // Event handlers
  //

  void _onLocation(bg.Location location) {
    print('[location] - $location');

    String odometerKM = (location.odometer / 1000.0).toStringAsFixed(1);

    setState(() {
      _content = encoder.convert(location.toMap());
      _odometer = odometerKM;
    });
  }

  void _onMotionChange(bg.Location location) {
    print('[motionchange] - $location');
  }

  void _onActivityChange(bg.ActivityChangeEvent event) {
    print('[activitychange] - $event');
    setState(() {
      _motionActivity = event.activity;
    });
  }

  void _onProviderChange(bg.ProviderChangeEvent event) {
    print('$event');

    setState(() {
      _content = encoder.convert(event.toMap());
    });
  }

  void _onConnectivityChange(bg.ConnectivityChangeEvent event) {
    print('$event');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Background Geolocation'),
        actions: <Widget>[
          Switch(
            value: _enabled,
            onChanged: _onClickEnable
          ),
        ]
      ),
      body: SingleChildScrollView(
          child: Text('$_content')
      ),
      bottomNavigationBar: BottomAppBar(
        child: Container(
          padding: const EdgeInsets.only(left: 5.0, right: 5.0),
          child: Row(
            mainAxisSize: MainAxisSize.max,
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              IconButton(
                icon: Icon(Icons.gps_fixed),
                onPressed: _onClickGetCurrentPosition,
              ),
              Text('$_motionActivity · $_odometer km'),
              MaterialButton(
                minWidth: 50.0,
                child: Icon((_isMoving) ? Icons.pause : Icons.play_arrow, color: Colors.white),
                color: (_isMoving) ? Colors.red : Colors.green,
                onPressed: _onClickChangePace
              )
            ]
          )
        )
      ),
    );
  }
}

Does the debug/test version allows testing on real iPhone and real Android phone?

iOS is free. Only Android consumes license keys.

Android is fully functional in DEBUG builds without a license so you can try before you buy.

Thanks, I will try this

@christocracy Is there any way to find out either its a Driving Mode or Walking mode?

Listen to onActivityChange event.

This package is awesome. I am wondering if there is a function where the app continues to get location after it gets terminated totally from the background?
Thanks in advance

My question is same as @AhmedTitef, is it possible?, or there is an autostart background service after terminated?

stopOnTerminate: false, startOnBoot: true

Can i use locationTemplate to build graphql json (example below)?
And what does a locationTemplate like for sending a batch from several locations?

{
    "variables": {{"objects": [{"lng": "1", "lat": "1", "driverID": 1},{"lng": "2", "lat": "2", "driverID": 2}]}},
    "extensions": {},
    "operationName": "InsertPoints",
    "query": "mutation InsertPoints($objects: [track_point_insert_input!]!) { \n insert_track_point(objects: $objects) { \n affected_rows \n} \n}"
}

Yes, you can. You just need to take care with escaping

\\\n

When i first install package work well but then says. "TrackingService destroyed "

You are assuming that note means something bad. It is not. It is exactly what's supposed to happen.

This plugin uses a number of foreground-services, keeping each activated only when required (when the device is in-motion). The default state of this plugin is to have no foreground-services activated, thus "destroyed".

When the device is detected to be in-motion (typically after movement of ~200 meters), a foreground-service is automatically re-launched and kept alive for as long as the device remains in motion, regardless if app is terminated or device rebooted.

If i use like that still work when app killed

Yes, that's what stopOnTerminate: false means.

For Android only, your Flutter App no longer exists and event-handlers will no longer be called (eg: BackgroundGeolocation.onLocation).

See Wiki Android Headless Mode

I suggest you try the /example app at flutter_background_geolocation repo first.

Do not touch the code. Just boot the app on your device and observe logs after terminating the app.

The Github repo has a link to purchase at the top:
https://www.transistorsoft.com/shop/products/flutter-background-geolocation

Hi @transistorsoft.

For Android if the configuration include stopOnTerminate: false and url: 'api endpoint' and params: {...}, when the app terminate, the plugin will continue uploading location to the endpoint with params too or only locations?

Yes. Config.params are appended to each http request, regardless of anything.

This plugin was originally developed for a disaster response app, tracking emergency workers in hurricanes and earthquakes where life depended on it.

you are free to manually engage location services by calling .changePace(true).

the automatic tracking requires the device move ~200 meters for iOS. For Android, the plugin is able to use the motion api to detect when device is moving (as long as user grants the “motion” runtime permission) and tracking can occur much less than 200 meters.

This is really not the place to seek specific tech support, in a code gist.

I suggest you post an issue at the GitHub repo.

hey, can i embed flutter app that using this library to native android app?

FWIW, I created a fork to update it for null safety and linting
https://gist.github.com/sisyfus/86a2817bc0d7c7f06e7cb866596c79d8

One question, in the case of the onLocation method, should it be configured only once for the whole app? or should it be instantiated in each part of the app where it is needed?

.onLocation is merely an event subscription. You can add as many as you wish or none at all. The /example app does this with separate subscribers updating info on the bottom-bar and another to print markers on the map.