Show latest chat messages

Question

Well, here’s the problem. I’ve been developing a What’s App-style app for a long time. As simple as it sounds, I can’t get the latest chat messages (sent by the user X received from the user Y) to be shown outside Chat Activity, as in the image below. I tried several things but without success. By the way I’m using Google Firebase.

Here’s the Chats Fragment code.

public class ChatsFragment extends Fragment {

    private View PrivateChatsView;
    private RecyclerView chatsList;

    private DatabaseReference ChatsRef, UsersRef, MessagesRef;
    private FirebaseAuth mAuth;
    private String currentUserID="";



    public ChatsFragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        PrivateChatsView = inflater.inflate(R.layout.fragment_chats, container, false);


        mAuth = FirebaseAuth.getInstance();
        currentUserID = mAuth.getCurrentUser().getUid();
        ChatsRef = FirebaseDatabase.getInstance().getReference().child("Contacts").child(currentUserID);
        UsersRef = FirebaseDatabase.getInstance().getReference().child("Users");
        MessagesRef = FirebaseDatabase.getInstance().getReference().child("Messages");

        chatsList = (RecyclerView) PrivateChatsView.findViewById(R.id.chats_list);
        chatsList.setLayoutManager(new LinearLayoutManager(getContext()));

        return PrivateChatsView;

    }


    @Override
    public void onStart()
    {
        super.onStart();

        FirebaseRecyclerOptions<Contacts> options =
                new FirebaseRecyclerOptions.Builder<Contacts>()
                        .setQuery(ChatsRef, Contacts.class)
                        .build();


        FirebaseRecyclerAdapter<Contacts, ChatsViewHolder> adapter =
                new FirebaseRecyclerAdapter<Contacts, ChatsViewHolder>(options) {
                    @Override
                    protected void onBindViewHolder(@NonNull final ChatsViewHolder holder, int position, @NonNull Contacts model)
                    {
                        final String usersIDs = getRef(position).getKey();
                        final String[] retImage = {"default_image"};

                        UsersRef.child(usersIDs).addValueEventListener(new ValueEventListener() {
                            @Override
                            public void onDataChange(DataSnapshot dataSnapshot)
                            {
                                if (dataSnapshot.exists())
                                {
                                    if (dataSnapshot.hasChild("image"))
                                    {
                                        retImage[0] = dataSnapshot.child("image").getValue().toString();
                                        Picasso.get().load(retImage[0]).into(holder.profileImage);
                                    }

                                    final String retName = dataSnapshot.child("name").getValue().toString();
                                    final String retStatus = dataSnapshot.child("status").getValue().toString();

                                    holder.userName.setText(retName);
                                    holder.userStatus.setText("Mostrar últimas mensagens aqui...");


                                    holder.itemView.setOnClickListener(new View.OnClickListener() {
                                        @Override
                                        public void onClick(View v)
                                        {
                                            Intent chatIntent = new Intent(getContext(), ChatActivity.class);
                                            chatIntent.putExtra("visit_user_id", usersIDs);
                                            chatIntent.putExtra("visit_user_name", retName);
                                            chatIntent.putExtra("visit_image", retImage[0]);

                                            startActivity(chatIntent);
                                        }
                                    });
                                }
                            }

                            @Override
                            public void onCancelled(DatabaseError databaseError)
                            {

                            }
                        });
                    }

                    @NonNull
                    @Override
                    public ChatsViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i)
                    {
                        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.users_display_layout, viewGroup, false);
                        return new ChatsViewHolder(view);
                    }
                };

        chatsList.setAdapter(adapter);
        adapter.startListening();
    }

    public static class ChatsViewHolder extends RecyclerView.ViewHolder
    {
        CircleImageView profileImage;
        TextView userStatus, userName;

        public ChatsViewHolder(@NonNull View itemView)
        {
            super(itemView);

            profileImage = itemView.findViewById(R.id.users_profile_image);
            userStatus = itemView.findViewById(R.id.user_status);
            userName = itemView.findViewById(R.id.user_profile_name);
        }
    }
}

Whoever can help me I really appreciate it, I’m in a bit of a bind here.