MainActivity.java

public class MainActivity extends Activity implements MapInteractor {
  MapView mapView;
  
  public void onCreate() {
    // View A from example
    MapFragment mapFragment = MapFragment.newInstance(); // Implements MapView interface
    // View B from example
    TaskFragment taskFragment = TaskFragment.newInstance();
    
    setTopFragment(mapFragment);
    setBottomFragment(taskFragment);
    
    mapView = mapFragment;
  }

  @Override
  public void putTaskOnMap(Task task) {
    // sends off to map view which goes to the map presenter to update the model then updates the view
    mapView.putTaskOnMap(task);
  }
  
  @Override
  public void centerMap() {
    mapView.centerMap();
  }
  
}

TaskFragment.java

public class TaskFragment extends Fragment implements TaskContract.View {
  
  private MapInteractor mapInteractor;
  
  @Override
  public void onAttach(Activity activity) {
    mapInteractor = (MapInteractor) activity;
  }

  @Override
  public void putTaskOnMap(Task task) {
    mapInteractor.putTaskOnMap(task);
  }

  @Override
  public void centerMap() {
    mapInteractor.centerMap();
  }
}

TaskPresenter.java

// Presenter B from the example
public class TaskPresenter {
    
  void start() {
    // TaskPresenter -> view -> activity -> MapView
    view.centerMap();
    // other ideas
    // mapInteractor.centerMap();
    // bus.post(centerMapEvent);
    // mapView.centerMap();
  }
  
  void getData() {
    Task task = taskRepository.getTask("id");

    view.display(task);
    view.putOnMap(task);
    // other ideas but doesn't make sense for centering the map
    // mapMarkerStore.addMapMarker(task); // MapPresenter would listen for changes and add or remove map makrer
  }
  
}