Live Location (Flutter + Google Map)

#livelocation #googlemaps #flutter

Integrating Google Map

To get started we need to first add Google Maps in our flutter application. This is done with the help of a Flutter plugin google_maps_flutter for integrating Google Maps in iOS and Android applications.

Add google_maps_flutter as a dependency in your pubspec.yaml file.

Get an API key at https://cloud.google.com/maps-platform/ and enable Google Map SDK. find detailed steps here.
Specify your API key in the application manifest android/app/src/main/AndroidManifest.xml

<manifest ...
  <application ...
    <meta-data android:name="com.google.android.geo.API\_KEY"
               android:value="YOUR API KEY"/>

import the package and you can now add a GoogleMap widget to your widget tree.

**import**'package:google\_maps\_flutter/google\_maps\_flutter.dart';

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

**class**  **MyApp**  **extends**  **StatelessWidget** {
**@override**
  Widget build(BuildContext context) {
**return** MaterialApp(
      title: 'Demo',
      home: MapSample(),
    );
  }
}

class MapSample extends StatefulWidget {
@override
\_MapSampleState createState() => \_MapSampleState();
}

class \_MapSampleState extends State<MapSample> {

GoogleMapController mapController;

LatLng \_initialPosition = LatLng(37.42796133588664, -122.885740655967);

void \_onMapCreated(GoogleMapController \_cntrl) async {
mapController = await \_cntrl;
}

return Scaffold(
  appBar: AppBar(
  backgroundColor: Color(0xff2758a1),
  title: Text('Demo'),
  ),
  body: Stack(
    children: <Widget>[
    GoogleMap(
      initialCameraPosition: CameraPosition(target: \_initialPosition, zoom: 10),
      mapType: MapType.normal,
      onMapCreated: \_onMapCreated,
      myLocationEnabled: true,
      myLocationButtonEnabled: true,
      zoomControlsEnabled: false,
      )
     ],
   ),
 );
}

Implementing live location

To implement live location we need to add Flutter Location Plugin . It's a Flutter plugin to easily handle a realtime location in iOS and Android.

Add Flutter Location Pluginas a dependency in your file.

import the package with

**import**'package:location/location.dart';

now we will make use of a listener to get continuous callbacks whenever the device position is changing.

Location location = **new** Location();

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

now let’s add this listener on our _onMapCreated Function with the functionality to animate the camera to each change in the device position.

void \_onMapCreated(GoogleMapController \_cntrl) async {

mapController = await \_cntrl;

locationSubscription = \_location.onLocationChanged.listen((l) {
  mapController.animateCamera(
    CameraUpdate.newCameraPosition(
      CameraPosition(target: LatLng(l.latitude, l.longitude),zoom: 18)),

);

}

Final code

**void** mai() => runApp(MyApp());

**class**  **MyApp**  **extends**  **StatelessWidget** {
**@override**
  Widget build(BuildContext context) {
**return** MaterialApp(
      title: 'Demo',
      home: MapSample(),
    );
  }
}

class MapSample extends StatefulWidget {
@override
\_MapSampleState createState() => \_MapSampleState();
}

class \_MapSampleState extends State<MapSample> {

GoogleMapController mapController;
Location location = **new** Location();

LatLng \_initialPosition = LatLng(37.42796133588664, -122.885740655967);

void \_onMapCreated(GoogleMapController \_cntrl) async {

mapController = await \_cntrl;

locationSubscription = \_location.onLocationChanged.listen((l) {
  mapController.animateCamera(
    CameraUpdate.newCameraPosition(
      CameraPosition(target: LatLng(l.latitude, l.longitude),zoom: 18)),

);

}

return Scaffold(
  appBar: AppBar(
  backgroundColor: Color(0xff2758a1),
  title: Text('Demo'),
  ),
  body: Stack(
    children: <Widget>[
    GoogleMap(
      initialCameraPosition: CameraPosition(target: \_initialPosition, zoom: 10),
      mapType: MapType.normal,
      onMapCreated: \_onMapCreated,
      myLocationEnabled: true,
      myLocationButtonEnabled: true,
      zoomControlsEnabled: false,
      )
     ],
   ),
 );
}