Java42(a).md

Read: 42 - (Location)

• With the Google Play services location APIs:

  • Your app can request the last known location of the user's device.

• The fused location provider -> is one of the location APIs in Google Play services. that provides a simple API and optimizes the device's use of battery power.

• So, How to make a single request for the location of a device using the getLastLocation() method in the fused location provider??

1. Set up Google Play services

Download and install the Google Play services component via the SDK Manager and add the library to your project.

Specify app permissions

Create location services client

In your activity's onCreate() method, create an instance of the Fused Location Provider Client as the following:

private FusedLocationProviderClient fusedLocationClient;

// ..

@Override
protected void onCreate(Bundle savedInstanceState) {
    // ...

    fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
}

Get the last known location

• To request the last known location, call the getLastLocation() method.

fusedLocationClient.getLastLocation()
        .addOnSuccessListener(this, new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                // Got last known location. In some rare situations this can be null.
                if (location != null) {
                    // Logic to handle location object
                }
            }
        });

• The location object may be null in the following situations:

1. Location is turned off in the device settings, because disabling location also clears the cache.

2. The device never recorded its location, like a new device or a device that has been restored to factory settings.

3. Google Play services on the device has restarted.

Choose the best location estimate

The FusedLocationProviderClient provides several methods to retrieve device location information, you can use any of them:

1. getLastLocation() gets a location estimate more quickly and minimizes battery usage.

2. getCurrentLocation() gets a fresher, more accurate location.

• If your app calls requestLocationUpdates(), your app can sometimes consume large amounts of power if location isn't available, or if the request isn't stopped correctly after obtaining a fresh location.