How to Display All Registered Users in Social Media Android App?

This is the Part 8 of “Build a Social Media App on Android Studio” tutorial, and we are going to cover the following functionalities in this article:

• We are going to Show all the Registered Users of our App.
• We are going to show the list of users in UsersFragment.

Step By Step Implementation

Step 1: Create a new java class

Working with the ModelUsers.java file. Created this activity to initialize the key so that we can retrieve the value of the key later.

Java

package com.example.socialmediaapp;

public class ModelUsers {
    String name;

    public ModelUsers() {
    }

    String onlineStatus;
    String typingTo;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getTypingTo() {
        return typingTo;
    }

    public void setTypingTo(String typingTo) {
        this.typingTo = typingTo;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getImage() {
        return image;
    }

    public void setImage(String image) {
        this.image = image;
    }

    public String getUid() {
        return uid;
    }

    public void setUid(String uid) {
        this.uid = uid;
    }

    public ModelUsers(String name, String onlineStatus, String typingTo, String email, String image, String uid) {
        this.name = name;
        this.onlineStatus = onlineStatus;
        this.typingTo = typingTo;
        this.email = email;
        this.image = image;
        this.uid = uid;
    }

    String email;

    String image;

    String uid;
}

Step 2: Create another new java class

Working with the AdapterUsers.java file.

Java

package com.example.socialmediaapp;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;
import com.google.firebase.auth.FirebaseAuth;

import java.util.List;

import de.hdodenhof.circleimageview.CircleImageView;

public class AdapterUsers extends RecyclerView.Adapter<AdapterUsers.MyHolder> {

    Context context;
    FirebaseAuth firebaseAuth;
    String uid;

    public AdapterUsers(Context context, List<ModelUsers> list) {
        this.context = context;
        this.list = list;
        firebaseAuth = FirebaseAuth.getInstance();
        uid = firebaseAuth.getUid();
    }

    List<ModelUsers> list;

    @NonNull
    @Override
    public MyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_users, parent, false);
        return new MyHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MyHolder holder, final int position) {
        final String hisuid = list.get(position).getUid();
        String userImage = list.get(position).getImage();
        String username = list.get(position).getName();
        String usermail = list.get(position).getEmail();
        holder.name.setText(username);
        holder.email.setText(usermail);
        try {
            Glide.with(context).load(userImage).into(holder.profiletv);
        } catch (Exception e) {
        }
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    class MyHolder extends RecyclerView.ViewHolder {

        CircleImageView profiletv;
        TextView name, email;

        public MyHolder(@NonNull View itemView) {
            super(itemView);
            profiletv = itemView.findViewById(R.id.imagep);
            name = itemView.findViewById(R.id.namep);
            email = itemView.findViewById(R.id.emailp);
        }
    }
}

Step 3: Working with the fragment_user.xml file

Navigate to the app > res > layout > fragment_user.xml and add the below code to that file. Below is the code for the fragment_user.xml file. 

XML

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".UsersFragment">

    <!-- TODO: Update blank fragment layout -->
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclep"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

Step 4: Working with the row_users.xml file

Create a new layout resource file and name the file as row_users. Below is the code for the row_users.xml file.

XML

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    app:cardBackgroundColor="@color/colorWhite"
    app:cardCornerRadius="2dp"
    app:cardElevation="2dp"
    app:cardUseCompatPadding="true"
    app:contentPadding="3dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <de.hdodenhof.circleimageview.CircleImageView
            android:id="@+id/imagep"
            android:layout_width="70dp"
            android:layout_height="70dp"
            android:src="@drawable/profile_image" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="5dp"
            android:layout_weight="1"
            android:orientation="vertical">

            <TextView
                android:id="@+id/namep"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Person NAme"
                android:textColor="@color/colorBlack"
                android:textSize="18sp" />

            <TextView
                android:id="@+id/emailp"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Person Email"
                android:textColor="@color/colorBlack" />

        </LinearLayout>

    </LinearLayout>

</androidx.cardview.widget.CardView>

Step  5: Working with the UsersFragmnet.java file

Go to the UsersFragmnet.java file and refer to the following code. Below is the code for the UsersFragmnet.java file.

Java

package com.example.socialmediaapp;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.List;

/**
 * A simple {@link Fragment} subclass.
 */
public class UsersFragment extends Fragment {

    RecyclerView recyclerView;
    AdapterUsers adapterUsers;
    List<ModelUsers> usersList;
    FirebaseAuth firebaseAuth;

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

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_users, container, false);
        recyclerView = view.findViewById(R.id.recyclep);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        usersList = new ArrayList<>();
        firebaseAuth = FirebaseAuth.getInstance();
        getAllUsers();
        return view;
    }

    private void getAllUsers() {
        final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                usersList.clear();
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    ModelUsers modelUsers = dataSnapshot1.getValue(ModelUsers.class);
                    if (modelUsers.getUid() != null && !modelUsers.getUid().equals(firebaseUser.getUid())) {
                        usersList.add(modelUsers);
                    }
                    adapterUsers = new AdapterUsers(getActivity(), usersList);
                    recyclerView.setAdapter(adapterUsers);
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        setHasOptionsMenu(true);
        super.onCreate(savedInstanceState);
    }
}

Output:

For all the drawable file used in this article please refer to this link: https://drive.google.com/drive/folders/1M_knOH_ugCuwSP5nkYzeD4dRp-Honzbe?usp=sharing

Below is the file structure after performing these operations: