在另一个片段中使用 Firestore 回调

Question

I'm trying to seperate my code into MVC-like pieces. I have a Fragment where I want to display the user name fetched from Firestore. Also I have a class (HomeController) where I put the logic. In this class I try to implement a method which fetches the user name from the document.

HomeController

public void getWelcomeNameText(final getNameCallback callback) {
    docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
        @Override
        public void onComplete(@NonNull Task<DocumentSnapshot> task) {
            if (task.isSuccessful()) {
                DocumentSnapshot document = task.getResult();
                if (document.exists()) {
                    welcomeName = document.getString("clientName");
                }
            }
            callback.onCallback(welcomeName);
        }
    });
}

I'm using interface for the callback.

public interface getNameCallback {
    void onCallback(String name);
}

Also in the constructor I call the method above.

public HomeController() {
    fAuth = FirebaseAuth.getInstance();
    fStore = FirebaseFirestore.getInstance();
    userID = fAuth.getUid();
    docRef = fStore.collection("Clients").document(userID);
    activeJobRef = fStore.collection("ActiveJobs");
    getWelcomeNameText(new getNameCallback() {
        @Override
        public void onCallback(String name) {
            welcomeName = name;
            //I want to pass this welcomeName to HomeFragment
        }
    });

}

This fetches the user name perfectly, but I want to use this method in my Fragment called HomeFragment to set the text of a TextView. So actually I want to pass the welcomeName variable. But actually I have no idea how to do it. I implement the getNameCallback in the Fragment.

HomeFragment

    public class HomeFragment extends Fragment implements HomeController.getNameCallback, View.OnClickListener {
    //variables

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        getActivity().getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        View view = inflater.inflate(R.layout.fragment_home, container, false);
        postJob = view.findViewById(R.id.button_add_job);
        logout = view.findViewById(R.id.button_sign_out);
        bottomNav = getActivity().findViewById(R.id.bottom_nav);
        bottomNav.setVisibility(View.VISIBLE);
        loginName = view.findViewById(R.id.textView_login_name);
        noDataText = view.findViewById(R.id.textView_no_active_job);

        homeController = new HomeController();

       //here I want something like: loginName.setText(userNameFromCallback);

       return view;
}

@Override
    public void onCallback(String name) {
    //maybe I have to do something here?
 }

Thanks for reading this - probably a very amateur - question!

Answer 1

Got the solution, I knew it was a noob-ish question:) I just called:

homeController.getWelcomeNameText(new HomeController.getNameCallback() {
            @Override
            public void onCallback(String name) {
                loginName.setText(name);
            }
        });