locate 1.0.0

A Flutter plugin to work with Android Location Services.

locate

A Flutter plugin to work with Android Location Services.

Important Points ::

• First of all, this flutter plugin doesn't work with IOS Location Service. Only Android Location Service is supported.
• AndroidX enabled.
• Kotlin(1.3.21) is used for implementation of platform side.
• Google Play Service Location is used to get precise location using both cellular network and GPS. api 'com.google.android.gms:play-services-location:16.0.0'
• AndroidX Core library used for backward compatibility. api 'androidx.core:core:1.0.1'
• CompileSDK and TargetSDK both are v28.

How to use it ???

Locate class has a singleton based architecture i.e. only a single instance can be created at a time. This class has four important methods that you'll be mostly using, which are as follows.

requestLocationPermission() :

• At the beginning try calling requestLocationPermission(), to check whether location permission is avaible not not.
• This method takes one optional positional argument provider, which defaults to gps.
• I'd recommend you to use ACCESS_FINE_LOCATION in your app to get precise location data.
• So, better you just don't pass any argument to requestLocationPermission().
• After it completes in async fashion, this returns a bool.
• If you get true, this means user has permitted you to access FINE_LOCATION of Android Device.
• Else good luck to you ;)

enableLocation() :

• So, if you get true, then lets go, to invoke enableLocation(), so that we can request user to enable location of device.
• This also completes in async fashion and then returns true or false based on the result of the Activity.

startLocationUpdate() :

• If we get true, we're good to call startLocationUpdate().
• Well this method takes two optional positional parameters.
• Imagine you have ACCESS_FINE_LOCATION permission for your app, then it'd be always better to invoke startLocationUpdate() as below :

  startLocationUpdate(locationServiceProvider: LocationServiceProvider.GMSBasedLocation);

• Where LocationServiceProvider is a class holding two const properties : GMSBasedLocation = '0'; & LocationManagerBasedLocation = '1';

• For using GooglePlayService based Location use LocationServiceProvider.GMSBasedLocation.

• And for android.location.LocationManager based Location use LocationServiceProvider.LocationManagerBasedLocation.

• Remember it's required to have ACCESS_FINE_LOCATION permission in order to user PlayService based Location using FusedLocationProviderClient.

• If you're satisfied with ACCESS_COARSE_LOCATION, then request for that permission using requestLocationPermission(provider: LocationProvider.Network);

• Well LocationProvider is also a class with two properties.

class LocationProvider {
static const String Network = 'network';
static const String GPS = 'gps';
}

• After that invoke startLocationUpdate() as follows for only network based Location Data.

  startLocationUpdate(locationServiceProvider: LocationServiceProvider.LocationManagerBasedLocation, locationProvider: LocationProvider.Network);

• You could also use it as follows, to use platform based LocationManager and ACCESS_FINE_LOCATION combination.

startLocationUpdate(locationServiceProvider: LocationServiceProvider.LocationManagerBasedLocation, locationProvider: LocationProvider.GPS);

• If you take a look at implementation of startLocationUpdate(){}, you could find out, that I've registered an EventChannel here, which sets a flow of LocationData Update from Platform Level to Locate class.
• Locate has a private method _onData(dynamic event){}, which gets invoked everytime App receive a Location Update from Platform.
• This method extracts location data and stores current location info in an instance of MyLocation class.
• If some error occurs, _onError(dynamic error){} gets invoked.

How to get this Location Data in you app's StateFulWidget Class and update that widget in dynamic fashion by calling setState() ??

So I've added another abstract class LocationDataCallBack, which has onData(Map<String, String> myLocatoin){}, that needs to be overridden wherever we implement LocationDataCallBack.

• In example app's, main.dart, I've implemented LocationDataCallBack in the class which extends State class.
• Now we can simply take the data from the Map<String, String> and update UI.
• Sample implementation of onData

  @override
void onData(Map<String, String> myLocation) {
  setState(() {
    myText =
        'Current Location : ${myLocation['longitude']}, ${myLocation['latitude']}\nUpdated at : ${DateTime.fromMillisecondsSinceEpoch(int.parse(myLocation['time'], radix: 10)).toString()}';
  });
}

stopLocationUpdate() :

• Now it's time to stop Location service. Lets call stopLocationUpdate(). And we're good to go.

• Always invoke methods in order while requesting Location Data using Locate.

• Follow the sequence requestLocationPermission() -> enableLocation() -> startLocationUpdate() -> stopLocationUpdate().

• Now you might ask me one question, how am I supposed to initialize Locate class ?

• In initState() of your StateFulWidget, where you implemented LocationDataCallBack, just create an instance of Locate class by invoking Locate(this).

• Locate's constructor takes an instance of LocationDataCallBack.

• Because that's what gets callbacked when new location data is available.

• So it was simple, was't it ???

Example App ::

Example App written using locate can be found here.

Getting Started ::

For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Courtesy ::

Last but not least, thanks to flutter, Dartlang and all of those persons who were somehow involved in developing such a great ecosystem, which has made the trouble of developing multiplatform apps significantly lesser.

Hope it was helpful :)