Why Should You Wrap LiveData With Your Own Abstraction

Presentation.java

interface MyGeneralObserver<T> {
    void notifyUpdate(T value);
}

interface ObservableViewState {
    void observeTitle(LifecycleOwner lifecycleOwner, MyGeneralObserver<String> observer);
}

interface IScreenPresenter extends ObservableViewState {
    void loadData();
}

class ScreenPresentationState implements ObservableViewState {

    private MutableLiveData<String> titleLiveData = new MutableLiveData<>();

    @Override
    public void observeTitle(LifecycleOwner lifecycleOwner, final MyGeneralObserver<String> observer) {
        titleLiveData.observe(lifecycleOwner, new Observer<String>() {
            @Override
            public void onChanged(String s) {
                if (s != null) {
                    observer.notifyUpdate(s);
                }
            }
        });
    }

    public void updateTitle(String title) {
        titleLiveData.postValue(title);
    }
}

class ScreenPresenter implements IScreenPresenter {

    private final ScreenPresentationState mState;

    public ScreenPresenter(ScreenPresentationState state) {
        mState = state;
    }

    @Override
    public void observeTitle(LifecycleOwner lifecycleOwner, MyGeneralObserver<String> observer) {
        mState.observeTitle(lifecycleOwner, observer);
    }

    @Override
    public void loadData() {
        mState.updateTitle(getSomeHowTheTitle());
    }

    private String getSomeHowTheTitle() {
        return "this is just example";
    }
}

class ScreenView extends AppCompatActivity {

    @Inject IScreenPresenter mPresenter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mPresenter.observeTitle(this, new MyGeneralObserver<String>() {
            @Override
            public void notifyUpdate(String value) {
                // render somehow the title
            }
        });

        mPresenter.loadData();
    }
}