Saturday, 14 December 2019

How To Build Real Time Chat Interface Using Firebase In Android.

The Firebase Realtime Database is a cloud-hosted database. Data is stored as JSON and synchronized in realtime to every connected client. When you build cross-platform apps with our iOS, Android, and JavaScript SDKs, all of your clients share one Realtime Database instance and automatically receive updates with the newest data.

We will apply the same concept for real time chat. Firstly, we will build chat interface with login and registration and than setup Firebase Realtime Database for messaging.

Refer the below link for complete sample code:-

Download Sample Code

Have a look on few code snippets,

//activity_users.xml
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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.androidchatapp.Users"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="No users found!"
        android:id="@+id/noUsersText"
        android:visibility="gone"/>

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/usersList"/>
</LinearLayout>

//activity_chat.xml
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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:background="#ffffff"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.androidchatapp.Chat">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_weight="20"
        android:layout_height="wrap_content"
        android:id="@+id/scrollView">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:id="@+id/layout1">

      </LinearLayout>
    </ScrollView>

    <include
        layout="@layout/message_area"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="bottom"
        android:layout_marginTop="5dp"/>
</LinearLayout>

//message_area.xml
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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimaryDark"
    android:gravity="bottom"
    android:orientation="horizontal">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:textColorHint="#CFD8DC"
        android:textColor="#CFD8DC"
        android:hint="Write a message..."
        android:id="@+id/messageArea"
        android:maxHeight="80dp"
        />

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="4"
        android:padding="4dp"
        android:src="@android:drawable/ic_menu_send"
        android:id="@+id/sendButton"/>
</LinearLayout>

//Users.java
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package com.elitetechnologies.realtimechat;

import android.app.ProgressDialog;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.Iterator;

public class Users extends AppCompatActivity {
    ListView usersList;
    TextView noUsersText;
    ArrayList<String> al = new ArrayList<>();
    int totalUsers = 0;
    ProgressDialog pd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_users);

        usersList = (ListView)findViewById(R.id.usersList);
        noUsersText = (TextView)findViewById(R.id.noUsersText);

        pd = new ProgressDialog(Users.this);
        pd.setMessage("Loading...");
        pd.show();

        String url = "https://real-time-chat-eb94c.firebaseio.com/users.json";

        StringRequest request = new StringRequest(Request.Method.GET, url, new Response.Listener<String>(){
            @Override
            public void onResponse(String s) {
                doOnSuccess(s);
            }
        },new Response.ErrorListener(){
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                System.out.println("" + volleyError);
            }
        });

        RequestQueue rQueue = Volley.newRequestQueue(Users.this);
        rQueue.add(request);

        usersList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                UserDetails.chatWith = al.get(position);
                startActivity(new Intent(Users.this, Chat.class));
            }
        });
    }

    public void doOnSuccess(String s){
        try {
            JSONObject obj = new JSONObject(s);

            Iterator i = obj.keys();
            String key = "";

            while(i.hasNext()){
                key = i.next().toString();

                if(!key.equals(UserDetails.username)) {
                    al.add(key);
                }

                totalUsers++;
            }

        } catch (JSONException e) {
            e.printStackTrace();
        }

        if(totalUsers <=1){
            noUsersText.setVisibility(View.VISIBLE);
            usersList.setVisibility(View.GONE);
        }
        else{
            noUsersText.setVisibility(View.GONE);
            usersList.setVisibility(View.VISIBLE);
            usersList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, al));
        }

        pd.dismiss();
    }
}

//Chat.java
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package com.elitetechnologies.realtimechat;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;

import com.firebase.client.ChildEventListener;
import com.firebase.client.DataSnapshot;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;

import java.util.HashMap;
import java.util.Map;

public class Chat extends AppCompatActivity {
    LinearLayout layout;
    ImageView sendButton;
    EditText messageArea;
    ScrollView scrollView;
    Firebase reference1, reference2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chat);

        layout = (LinearLayout)findViewById(R.id.layout1);
        sendButton = (ImageView)findViewById(R.id.sendButton);
        messageArea = (EditText)findViewById(R.id.messageArea);
        scrollView = (ScrollView)findViewById(R.id.scrollView);

        Firebase.setAndroidContext(this);
        reference1 = new Firebase("https://real-time-chat-eb94c.firebaseio.com/message/" + UserDetails.username + "_" + UserDetails.chatWith);
        reference2 = new Firebase("https://real-time-chat-eb94c.firebaseio.com/message/" + UserDetails.chatWith + "_" + UserDetails.username);

        sendButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String messageText = messageArea.getText().toString();

                if(!messageText.equals("")){
                    Map<String, String> map = new HashMap<String, String>();
                    map.put("message", messageText);
                    map.put("user", UserDetails.username);
                    reference1.push().setValue(map);
                    reference2.push().setValue(map);
                }
            }
        });

        reference1.addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                Map map = dataSnapshot.getValue(Map.class);
                String message = map.get("message").toString();
                String userName = map.get("user").toString();

                if(userName.equals(UserDetails.username)){
                    addMessageBox("You:-\n" + message, 1);
                }
                else{
                    addMessageBox(UserDetails.chatWith + ":-\n" + message, 2);
                }
            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(FirebaseError firebaseError) {

            }
        });
    }

    public void addMessageBox(String message, int type){
        TextView textView = new TextView(Chat.this);
        textView.setText(message);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        lp.setMargins(0, 0, 0, 10);
        textView.setLayoutParams(lp);

        if(type == 1) {
            textView.setBackgroundResource(R.drawable.rounded_corner1);
        }
        else{
            textView.setBackgroundResource(R.drawable.rounded_corner2);
        }

        layout.addView(textView);
        scrollView.fullScroll(View.FOCUS_DOWN);
    }
}