Android Core library

Current version: v1.3.0 View changelog

  • Real-time device location
  • Checking and requesting permissions

The Mapbox Core Libraries for Android are a set of utilities that help you with permissions, device location, and connectivity within your Android project. With these libraries, you can:

  • Check for, request, and respond to any number of Android system permissions such as device location or camera.
  • Check for and respond to a change in the device's internet connectivity status.
  • Retrieve a device's real-time location.

This core module has no dependencies on any of the other Mapbox Java modules and only depends on having the Android API plugin inside your project.

Installation

Gradle

  1. Open Android Studio.
  2. Open up your application's build.gradle file.
  3. Make sure that your project's minSdkVersion is at API 14 or higher.
  4. Under dependencies, add a new build rule for the latest mapbox-android-core version (see below).
  5. Click on Sync Project with Gradle Files near the toolbar in Android Studio.
implementation 'com.mapbox.mapboxsdk:mapbox-android-core:1.3.0'

Note: ProGuard directives are included in the Android dependencies to preserve the required classes.

PermissionsManager

If you build your Android project targeting API level 23 or higher, then your application will need to request permission during runtime. Handling this directly in your activity produces boilerplate code and can often be hard to manage. That's where the PermissionsManager class comes into play. With the PermissionsManager class, you can check whether the user has granted location permission and request permissions if the user hasn't granted them yet. You can use PermissionsManager permissionsManager = new PermissionsManager(this); if you're implementing PermissionsListener.

Once you have set up your permissions manager, you will still need to override onRequestPermissionsResult() and call the permissionsManager's same method.

Note: The PermissionsManager can be used for requesting other permissions in addition to location.

PermissionsManager permissionsManager = new PermissionsManager(this);
if (PermissionsManager.areLocationPermissionsGranted(this)) {
// Permission sensitive logic called here, such as activating the Maps SDK's LocationComponent to show the device's location
} else {
permissionsManager = new PermissionsManager(this);
permissionsManager.requestLocationPermissions(this);
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
permissionsManager.onRequestPermissionsResult(requestCode, permissions, grantResults);
}

PermissionsListener

The PermissionsListener is an interface that needs to be set up and passed into the PermissionsManager's constructor. You can use permissionsManager = new PermissionsManager(this); if you're implementing PermissionsListener. You'll notice that PermissionsListener overrides the onExplanationNeeded() and onPermissionResult() methods. An explanation isn't required but strongly encouraged to allow the user to understand why you are requesting this permission.

The permission result is invoked once the user decides whether to allow or deny the permission. A boolean value is given, which you can then use to write an if statement. Both cases should be handled correctly. Continue with your permission-sensitive logic if the user approves. Otherwise, if the user denies, display a message that tells the user that the permission is required for your application to work.

PermissionsListener permissionsListener = new PermissionsListener() {
@Override
public void onExplanationNeeded(List<String> permissionsToExplain) {
}
@Override
public void onPermissionResult(boolean granted) {
if (granted) {
// Permission sensitive logic called here, such as activating the Maps SDK's LocationComponent to show the device's location
} else {
// User denied the permission
}
}
};

LocationEngine

If your application needs location information, the LocationEngine class can help you get this information while also simplifying the process and being flexible enough to use different services. The LocationEngine found in the core module now supports the following location providers:

  • Google's Fused Location Providers
  • Android GPS and Network Providers

If you are using the Mapbox Maps SDK for Android, create a LocationEngine object using:

LocationEngine locationEngine = LocationEngineProvider.getBestLocationEngine(this);

This will obtain the best location engine that is available and eliminate the need to create a new LocationEngine from scratch.

Requesting location updates

You'll need a class that implements LocationEngineCallback<LocationEngineResult>. Make sure the class requires Android system Activity as a constructor parameter. This class will serve as a "callback" and it's needed because a LocationEngine memory leak is possible if the activity/fragment directly implements the LocationEngineCallback<LocationEngineResult>. The WeakReference setup avoids the leak.

When implementing the LocationEngineCallback interface, you are also required to override the onSuccess() and onFailure() methods. OnSuccess() runs whenever the Mapbox Core Libraries identifies a change in the device's location. result.getLastLocation() gives you a Location object that contains the latitude and longitude values. Now you can display the values in your app's UI, save it in memory, send it to your backend server, or use the device location information how you'd like.

private static class LocationListeningCallback
implements LocationEngineCallback<LocationEngineResult> {
private final WeakReference<MainActivity> activityWeakReference;
LocationListeningCallback(MainActivity activity) {
this.activityWeakReference = new WeakReference<>(activity);
}
@Override
public void onSuccess(LocationEngineResult result) {
// The LocationEngineCallback interface's method which fires when the device's location has changed.
Location lastLocation = result.getLastLocation();
}
@Override
public void onFailure(@NonNull Exception exception) {
// The LocationEngineCallback interface's method which fires when the device's location can not be captured
}
}

Globally declare an instance of the class you created above:

private LocationListeningCallback callback = new LocationListeningCallback(this);

Request location updates once you know location permissions have been granted:

long DEFAULT_INTERVAL_IN_MILLISECONDS = 1000L;
long DEFAULT_MAX_WAIT_TIME = DEFAULT_INTERVAL_IN_MILLISECONDS * 5;
LocationEngine locationEngine = LocationEngineProvider.getBestLocationEngine(this);
LocationEngineRequest request = new LocationEngineRequest.Builder(DEFAULT_INTERVAL_IN_MILLISECONDS)
.setPriority(LocationEngineRequest.PRIORITY_NO_POWER)
.setMaxWaitTime(DEFAULT_MAX_WAIT_TIME)
.build();
locationEngine.requestLocationUpdates(request, callback, getMainLooper());
locationEngine.getLastLocation(callback);

To prevent your application from having a memory leak, it is a good idea to stop requesting location updates inside of your activity's onStop() method.

@Override
protected void onStop() {
super.onStop();
if (locationEngine != null) {
locationEngine.removeLocationUpdates(callback);
}
mapView.onStop();
}
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