The 11.0.0 release of the Google Play services SDK includes a new way to access
LocationServices.
The new APIs do not require your app to manually manage a connection to Google
Play services through a GoogleApiClient
. This reduces boilerplate
and common pitfalls in your app.
Read more below, or head straight to the updated location samples on GitHub.
Why not use GoogleApiClient?
The LocationServices APIs allow you to access device location, set up geofences, prompt the user to enable location on the device and more. In order to access these services, the app must connect to Google Play services, which can involve error-prone connection logic. For example, can you spot the crash in the app below?
Note: we'll assume our app has the
ACCESS_FINE_LOCATION
permission, which is required to get the
user's exact location using the LocationServices APIs.
public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener { @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); GoogleApiClient client = new GoogleApiClient.Builder(this) .enableAutoManage(this, this) .addApi(LocationServices.API) .build(); client.connect(); PendingResultresult = LocationServices.FusedLocationApi.requestLocationUpdates( client, LocationRequest.create(), pendingIntent); result.setResultCallback(new ResultCallback () { @Override public void onResult(@NonNull Status status) { Log.d(TAG, "Result: " + status.getStatusMessage()); } }); } // ... }
If you pointed to the requestLocationUpdates()
call, you're right!
That call throws an IllegalStateException
, since the
GoogleApiClient
is has not yet connected. The call to
connect()
is asynchronous.
While the code above looks like it should work, it's missing a ConnectionCallbacks
argument to the GoogleApiClient
builder. The call to request
location updates should only be made after the onConnected
callback
has fired:
public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener, GoogleApiClient.ConnectionCallbacks { private GoogleApiClient client; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); client = new GoogleApiClient.Builder(this) .enableAutoManage(this, this) .addApi(LocationServices.API) .addConnectionCallbacks(this) .build(); client.connect(); } @Override public void onConnected(@Nullable Bundle bundle) { PendingResultresult = LocationServices.FusedLocationApi.requestLocationUpdates( client, LocationRequest.create(), pendingIntent); result.setResultCallback(new ResultCallback () { @Override public void onResult(@NonNull Status status) { Log.d(TAG, "Result: " + status.getStatusMessage()); } }); } // ... }
Now the code works, but it's not ideal for a few reasons:
- It would be hard to refactor into shared classes if, for instance, you wanted to access Location Services in multiple activities.
- The app connects optimistically in
onCreate
even if Location Services are not needed until later (for example, after user input). - It does not handle the case where the app fails to connect to Google Play services.
- There is a lot of boilerplate connection logic before getting started with location updates.
A better developer experience
The new LocationServices
APIs are much simpler and will make your
code less error prone. The connection logic is handled automatically, and you
only need to attach a single completion listener:
public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this); client.requestLocationUpdates(LocationRequest.create(), pendingIntent) .addOnCompleteListener(new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { Log.d("MainActivity", "Result: " + task.getResult()); } }); } }
The new API immediately improves the code in a few ways:
- The API calls automatically wait for the service connection to be
established, which removes the need to wait for
onConnected
before making requests. - It uses the Task API which makes it easier to compose asynchronous operations.
- The code is self-contained and could easily be moved into a shared utility class or similar.
- You don't need to understand the underlying connection process to start coding.
What happened to all of the callbacks?
The new API will automatically resolve certain connection failures for you, so you don't need to write code that for things like prompting the user to update Google Play services. Rather than exposing connection failures globally in the onConnectionFailed method, connection problems will fail the Task with an ApiException:
client.requestLocationUpdates(LocationRequest.create(), pendingIntent) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { if (e instanceof ApiException) { Log.w(TAG, ((ApiException) e).getStatusMessage()); } else { Log.w(TAG, e.getMessage()); } } });
Try it for yourself
Try the new LocationServices
APIs out for yourself in your own app
or head over to the android-play-location
samples on GitHub and see more examples of how the new clients reduce
boilerplate and simplify logic.