Java – Android Application Architecture: Implements user permission in lifecycle

Android Application Architecture: Implements user permission in lifecycle… here is a solution to the problem.

Android Application Architecture: Implements user permission in lifecycle

I have a LocationListener that extends the LiveData class. Starting with Android 6.0, request permissions at runtime. Now, when I try to implement the LiveData class, it requires permission checking in the onActive() function. I have to make boilerplate code in each activity for the permissions requested and the results received. Is there a way to move like this
The onRequestPermissionsResult() and checkSelfPermission() functions to LocationListener ?

Location fragment .java

public class LocationFragment extends LifecycleFragment {

private FragmentLocationBinding binding;

public LocationFragment() {
     Required empty public constructor
  }

@Override
  public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if (ContextCompat.checkSelfPermission(getActivity(),
        permission. ACCESS_COARSE_LOCATION)
        != PackageManager.PERMISSION_GRANTED) {
       Should we show an explanation?
      if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),
          Manifest.permission.ACCESS_COARSE_LOCATION)) {
         Show an explanation to the user *asynchronously* -- don't block
         this thread waiting for the user's response! After the user
         sees the explanation, try again to request the permission.

} else {

 No explanation needed, we can request the permission.

ActivityCompat.requestPermissions(getActivity(),
            new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
            200);

 MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
         app-defined int constant. The callback method gets the
         result of the request.
      }
    }
    get the viewmodel from activity
    LastLocationViewModel lastLocationViewModel = ViewModelProviders.of(getActivity())
        .get(LastLocationViewModel.class);
    lastLocationViewModel.getLastKnowLocation().observe(this, location -> {
      binding.setLocation(location);
    });

}

@Override
  public void onRequestPermissionsResult(int requestCode,
      String permissions[], int[] grantResults) {
    switch (requestCode) {
      case 200: {
         If request is cancelled, the result arrays are empty.
        if (grantResults.length > 0
            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
          Toast.makeText(getActivity(), "Rights Granted", Toast.LENGTH_SHORT).show();
           permission was granted, yay! Do the
           contacts-related task you need to do.
        } else {
           permission denied, boo! Disable the
           functionality that depends on this permission.
        }
        return;
      }

 other 'case' lines to check for other
       permissions this app might request
    }
  }

@Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {
     Inflate the layout for this fragment
    binding = DataBindingUtil
        .inflate(LayoutInflater.from(getActivity()), R.layout.fragment_location, null, false);
    return binding.getRoot();
  }

}

LastLocationListener.java

public class LastLocationListener extends LiveData<Location> {

private LocationManager locationManager;

private Context context;

private LocationListener listener = new LocationListener() {
    @Override
    public void onLocationChanged(Location location) {

Log.d("Location Msg", location.toString());
      setValue(location);
    }

@Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

}

@Override
    public void onProviderEnabled(String s) {

}

@Override
    public void onProviderDisabled(String s) {

}
  };

public LastLocationListener(Context context) {
    this.context = context;
    locationManager = (LocationManager) context.getSystemService(
        Context.LOCATION_SERVICE);
  }

@Override
  protected void onActive() {
    if (ActivityCompat.checkSelfPermission(context, permission. ACCESS_FINE_LOCATION)
        != PackageManager.PERMISSION_GRANTED
        && ActivityCompat.checkSelfPermission(context, permission. ACCESS_COARSE_LOCATION)
        != PackageManager.PERMISSION_GRANTED) {
       TODO: Consider calling
          ActivityCompat#requestPermissions
       here to request the missing permissions, and then overriding
         public void onRequestPermissionsResult(int requestCode, String[] permissions,
                                                int[] grantResults)
       to handle the case where the user grants the permission. See the documentation
       for ActivityCompat#requestPermissions for more details.
      return;
    }
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, listener);
  }

@Override
  protected void onInactive() {
    locationManager.removeUpdates(listener);
  }

}

Solution

when I tried to implements the LiveData Class and it required the permission checking in onActive() function

No, it doesn’t. What you see is a lint warning that you can suppress.
What is required is that you have permission before attempting to use this particular bit of LiveData.

Is there any way to move such onRequestPermissionsResult() and checkSelfPermission() functions to the LocationListener ?

No.

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