LocationSettingsRequest dialog to enable GPS - onA

Question

Part of my app requires location services, so if location is currently turned off, the app will prompt the user to enable it. Here is how I am doing it: (Also seen in this Stack Overflow answer)

LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
            .addLocationRequest(mLocationRequest);
builder.setAlwaysShow(true);

PendingResult<LocationSettingsResult> result = LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());

result.setResultCallback(new ResultCallback<LocationSettingsResult>() 
{
     @Override
     public void onResult(LocationSettingsResult result) 
     {
         final Status status = result.getStatus();
         final LocationSettingsStates = result.getLocationSettingsStates();
         switch (status.getStatusCode()) 
         {
             case LocationSettingsStatusCodes.SUCCESS:
                 // All location settings are satisfied. The client can initialize location
                 // requests here.
                 ...
                 Log.d("onResult", "SUCCESS");
                 break;
             case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                 // Location settings are not satisfied. But could be fixed by showing the user
                 // a dialog.
                 Log.d("onResult", "RESOLUTION_REQUIRED");
                 try 
                 {
                     // Show the dialog by calling startResolutionForResult(),
                     // and check the result in onActivityResult().
                     status.startResolutionForResult(OuterClass.this, REQUEST_LOCATION);
                 } 
                 catch (SendIntentException e) 
                 {
                     // Ignore the error.
                 }
                 break;
             case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                 // Location settings are not satisfied. However, we have no way to fix the
                 // settings so we won't show the dialog.
                 ...
                 Log.d("onResult", "UNAVAILABLE");
                 break;
         }
     }
 });

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    // This log is never called
    Log.d("onActivityResult()", Integer.toString(resultCode));

    final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
    switch (requestCode)
    {
        case REQUEST_LOCATION:
            switch (resultCode)
            {
                case Activity.RESULT_OK:
                {
                    // All required changes were successfully made
                    break;
                }
                case Activity.RESULT_CANCELED:
                {
                    // The user was asked to change settings, but chose not to
                    break;
                }
                default:
                {      
                    break;
                }
            }
            break;
    }
}

This code works well, however, onActivityResult() is always skipped. Whether or not the user presses Yes, No, or back from the Dialog, onActivityResult() doesn't run.

I need Android to call onActivityResult() so if the user chooses not to turn on location services, I can handle it appropriately.

Google's developer page (and the code above) explicitly says that onActivityResult() should be called. Anyone know why it's being skipped?

I also don't know what the purpose of this line is:

final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);

Thanks!

Edit: Basic information on the structure of my app:

• This code is contained within the onResume() method of a Fragment which implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, and LocationListener to receive location updates. Example seen here.
• In onLocationChanged() the Fragment will have a custom View call invalidate() and re-draw itself with updated information.

Answer 1

Saving fragment field in activity (as Daniel suggested) is not often a good decision, cause imagine you have multiple fragments and each contains location code. I did it in a different manner:

public class MainActivity extends Activity implements PlaceFragment.SettingsModifyHandler {

    private static final int LOCATION_SETTINGS_RESULT = 1;
    private OnResultCallback placeCallback;

    ...

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == LOCATION_SETTINGS_RESULT) {
            if (resultCode == Activity.RESULT_OK) {
                placeCallback.resultOk();
            } else {
                placeCallback.resultFail();
            }
        placeCallback = null;
        }
    }

    @Override
    public void handle(IntentSender intentSender, OnResultCallback callback) {
        placeCallback = callback;
        try {
            startIntentSenderForResult(intentSender, LOCATION_SETTINGS_RESULT, null, 0, 0, 0);
        } catch (IntentSender.SendIntentException e) {
            callback.resultFail();
        }
    }
}

public class PlaceFragment extends Fragment {

    private SettingsModifyHandler settingsModifyHandler;

    ...

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        if (context instanceof SettingsModifyHandler) {
            settingsModifyHandler = (SettingsModifyHandler) context;
        } else {
            throw new RuntimeException("Parent activity must implement PlaceFragment.SettingsModifyHandler interface");
        }
    }

    /* Callback from module, where you implemented status.getStatusCode().LocationSettingsStatusCodes.RESOLUTION_REQUIRED case
    (status is instance of com.google.android.gms.common.api.Status)
    You provide intentSender here through status.getResolution().getIntentSender() */
    @Override
    public void placeLoadError(IntentSender sender) {
        TextView view_text = (TextView) root.findViewById(R.id.text_error);
        TextView view_btn = (TextView) root.findViewById(R.id.btn_reply);

        view_text.setText("Need to change location settings");
        view_btn.setText("Change");
        view_btn.setOnClickListener(v -> {
            settingsModifyHandler.handle(sender, new SettingsModifyHandler.OnResultCallback() {
                @Override
                public void resultOk() {
                    presenter.loadPlace(placeId);
                }

                @Override
                public void resultFail() {
                    ToastUtils.show("You should change location settings!");
                }
            });
        });
    }

    public interface SettingsModifyHandler {
        void handle(IntentSender intentSender, OnResultCallback callback);

        interface OnResultCallback {
            void resultOk();
            void resultFail();
        }
    }
}