Building A One To One/Group Chat Experience

The One-to-One Chat feature provides a direct messaging interface for Android applications, ideal for **support chats, dating apps, and private messaging **. This implementation launches directly into a specific chat conversation without showing a conversation list, providing a focused messaging experience.

User Interface Preview

Key Components

Message Header – Displays user/group name, avatar, and status.
Message List – Shows chat history with real-time message updates.
Message Composer – Provides input field for sending text messages, media, and attachments.

Step-by-Step Guide

Use Case

This pattern is ideal when you want to:

Launch a chat directly from a user profile or contact card
Open a support chat from a help button
Start a conversation from a notification
Navigate to a specific chat without showing the conversation list

The user or group ID is passed via Intent extras when launching the Activity.

Step 1: Set Up Message Activity

Create an Activity - MessageActivity to display the full-screen chat interface.

Layout

Define the layout with CometChatMessageHeader, CometChatMessageList, and CometChatMessageComposer in activity_message.xml:

activity_message.xml

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MessageActivity">

    <!-- Message Header -->
    <com.cometchat.chatuikit.messageheader.CometChatMessageHeader
        android:id="@+id/message_header"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <!-- Message List -->
    <com.cometchat.chatuikit.messagelist.CometChatMessageList
        android:id="@+id/message_list"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toBottomOf="@id/message_header"
        app:layout_constraintBottom_toTopOf="@id/message_composer"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <!-- Message Composer -->
    <com.cometchat.chatuikit.messagecomposer.CometChatMessageComposer
        android:id="@+id/message_composer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Activity

Retrieve the user or group ID from the Intent extras and configure the message components:

Kotlin
Java

MessageActivity.kt

import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import com.cometchat.chat.core.CometChat
import com.cometchat.chat.exceptions.CometChatException
import com.cometchat.chat.models.Group
import com.cometchat.chat.models.User
import com.cometchat.chatuikit.messagecomposer.CometChatMessageComposer
import com.cometchat.chatuikit.messageheader.CometChatMessageHeader
import com.cometchat.chatuikit.messagelist.CometChatMessageList

class MessageActivity : AppCompatActivity() {
    private lateinit var messageHeader: CometChatMessageHeader
    private lateinit var messageList: CometChatMessageList
    private lateinit var messageComposer: CometChatMessageComposer

    private var uid: String? = null
    private var guid: String? = null

    private val TAG = "MessageActivity"

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_message)

        initializeViews()
        setupChat()
        setupHeaderBackButton()
    }

    private fun initializeViews() {
        messageHeader = findViewById(R.id.message_header)
        messageList = findViewById(R.id.message_list)
        messageComposer = findViewById(R.id.message_composer)
    }

    private fun setupChat() {
        uid = intent.getStringExtra("uid")
        guid = intent.getStringExtra("guid")

        when {
            uid != null -> setupUserChat(uid!!)
            guid != null -> setupGroupChat(guid!!)
            else -> {
                Log.e(TAG, "No user ID or group ID provided")
                showError("Missing user ID or group ID")
                finish()
            }
        }
    }

    private fun setupUserChat(userId: String) {
        CometChat.getUser(userId, object : CometChat.CallbackListener<User>() {
            override fun onSuccess(user: User) {
                Log.d(TAG, "Successfully loaded user: ${user.uid}")
                messageHeader.setUser(user)
                messageList.setUser(user)
                messageComposer.setUser(user)
            }

            override fun onError(e: CometChatException?) {
                Log.e(TAG, "Error loading user: ${e?.message}")
                showError("Could not find user: ${e?.message}")
                finish()
            }
        })
    }

    private fun setupGroupChat(groupId: String) {
        CometChat.getGroup(groupId, object : CometChat.CallbackListener<Group>() {
            override fun onSuccess(group: Group) {
                Log.d(TAG, "Successfully loaded group: ${group.guid}")
                messageHeader.setGroup(group)
                messageList.setGroup(group)
                messageComposer.setGroup(group)
            }

            override fun onError(e: CometChatException?) {
                Log.e(TAG, "Error loading group: ${e?.message}")
                showError("Could not find group: ${e?.message}")
                finish()
            }
        })
    }

    private fun setupHeaderBackButton() {
        messageHeader.setOnBackButtonPressed {
            finish()
        }
    }

    private fun showError(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
    }
}

MessageActivity.java

import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.cometchat.chat.core.CometChat;
import com.cometchat.chat.exceptions.CometChatException;
import com.cometchat.chat.models.Group;
import com.cometchat.chat.models.User;
import com.cometchat.chatuikit.messagecomposer.CometChatMessageComposer;
import com.cometchat.chatuikit.messageheader.CometChatMessageHeader;
import com.cometchat.chatuikit.messagelist.CometChatMessageList;

public class MessageActivity extends AppCompatActivity {

    private static final String TAG = "MessageActivity";

    private CometChatMessageHeader messageHeader;
    private CometChatMessageList messageList;
    private CometChatMessageComposer messageComposer;

    private String uid;
    private String guid;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setDecorFitsSystemWindows(false); // enableEdgeToEdge()
        setContentView(R.layout.activity_message);

        initializeViews();
        setupChat();
        setupHeaderBackButton();
    }

    private void initializeViews() {
        messageHeader = findViewById(R.id.message_header);
        messageList = findViewById(R.id.message_list);
        messageComposer = findViewById(R.id.message_composer);
    }

    private void setupChat() {
        uid = getIntent().getStringExtra("uid");
        guid = getIntent().getStringExtra("guid");

        if (uid != null) {
            setupUserChat(uid);
        } else if (guid != null) {
            setupGroupChat(guid);
        } else {
            Log.e(TAG, "No user ID or group ID provided");
            showError("Missing user ID or group ID");
            finish();
        }
    }

    private void setupUserChat(String userId) {
        CometChat.getUser(userId, new CometChat.CallbackListener<User>() {
            @Override
            public void onSuccess(User user) {
                Log.d(TAG, "Successfully loaded user: " + user.getUid());
                messageHeader.setUser(user);
                messageList.setUser(user);
                messageComposer.setUser(user);
            }

            @Override
            public void onError(CometChatException e) {
                Log.e(TAG, "Error loading user: " + (e != null ? e.getMessage() : "Unknown error"));
                showError("Could not find user: " + (e != null ? e.getMessage() : ""));
                finish();
            }
        });
    }

    private void setupGroupChat(String groupId) {
        CometChat.getGroup(groupId, new CometChat.CallbackListener<Group>() {
            @Override
            public void onSuccess(Group group) {
                Log.d(TAG, "Successfully loaded group: " + group.getGuid());
                messageHeader.setGroup(group);
                messageList.setGroup(group);
                messageComposer.setGroup(group);
            }

            @Override
            public void onError(CometChatException e) {
                Log.e(TAG, "Error loading group: " + (e != null ? e.getMessage() : "Unknown error"));
                showError("Could not find group: " + (e != null ? e.getMessage() : ""));
                finish();
            }
        });
    }

    private void setupHeaderBackButton() {
        messageHeader.setOnBackButtonPressed(() -> finish());
    }

    private void showError(String message) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
    }
}

You must use an activity that supports the lifecycle API, such as:

AppCompatActivity
ComponentActivity
FragmentActivity

This is necessary to properly manage the UI Kit’s lifecycle events.

Step 2: Launch MessageActivity from Your App

Update your MainActivity (or any other Activity) to launch MessageActivity with the appropriate user or group ID:

Passing Data via IntentYou can pass either:

uid (String) - for one-to-one chats
guid (String) - for group chats

The MessageActivity will automatically detect which type of chat to display based on the Intent extras.

Kotlin
Java

MainActivity.kt

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import androidx.activity.enableEdgeToEdge
import com.cometchat.chat.core.CometChat
import com.cometchat.chat.exceptions.CometChatException
import com.cometchat.chat.models.User
import com.cometchat.chatuikit.shared.cometchatuikit.CometChatUIKit
import com.cometchat.chatuikit.shared.cometchatuikit.UIKitSettings

class MainActivity : ComponentActivity() {

    private val TAG = "MainActivity"

    private val appID = "APP_ID" // Replace with your App ID
    private val region = "REGION" // Replace with your App Region
    private val authKey = "AUTH_KEY" // Replace with your Auth Key or leave blank if you are authenticating using Auth Token

    private val uiKitSettings = UIKitSettings.UIKitSettingsBuilder()
        .setRegion(region)
        .setAppId(appID)
        .setAuthKey(authKey)
        .subscribePresenceForAllUsers()
        .build()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

        CometChatUIKit.init(this, uiKitSettings, object : CometChat.CallbackListener<String?>() {
            override fun onSuccess(successString: String?) {

                Log.d(TAG, "Initialization completed successfully")

                loginUser()
            }

            override fun onError(e: CometChatException?) {}
        })
    }

    private fun loginUser() {
        CometChatUIKit.login("cometchat-uid-1", object : CometChat.CallbackListener<User>() {
            override fun onSuccess(user: User) {

                // Launch One-to-One or Group Chat Screen
                 val intent = Intent(this@MainActivity, MessageActivity::class.java)
                 intent.putExtra("uid", "cometchat-uid-1")
                 startActivity(intent)
            }

            override fun onError(e: CometChatException) {
                // Handle login failure (e.g. show error message or retry)
                Log.e("Login", "Login failed: ${e.message}")
            }
        })
    }
}

MainActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import androidx.activity.ComponentActivity;
import com.cometchat.chat.core.CometChat;
import com.cometchat.chat.exceptions.CometChatException;
import com.cometchat.chat.models.User;
import com.cometchat.chatuikit.shared.cometchatuikit.CometChatUIKit;
import com.cometchat.chatuikit.shared.cometchatuikit.UIKitSettings;

public class MainActivity extends ComponentActivity {

    private static final String TAG = "MainActivity";

    private final String appID = "APP_ID"; // Replace with your App ID
    private final String region = "REGION"; // Replace with your App Region
    private final String authKey = "AUTH_KEY"; // Replace with your Auth Key

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setDecorFitsSystemWindows(false); // Equivalent to enableEdgeToEdge()

        UIKitSettings uiKitSettings = new UIKitSettings.UIKitSettingsBuilder()
                .setRegion(region)
                .setAppId(appID)
                .setAuthKey(authKey)
                .subscribePresenceForAllUsers()
                .build();

        CometChatUIKit.init(this, uiKitSettings, new CometChat.CallbackListener<String>() {
            @Override
            public void onSuccess(String success) {
                Log.d(TAG, "Initialization completed successfully");
                loginUser();
            }

            @Override
            public void onError(CometChatException e) {
                Log.e(TAG, "Initialization failed: " + (e != null ? e.getMessage() : "Unknown error"));
            }
        });
    }

    private void loginUser() {
        CometChatUIKit.login("cometchat-uid-1", new CometChat.CallbackListener<User>() {
            @Override
            public void onSuccess(User user) {
                Log.d(TAG, "Login successful for user: " + user.getUid());

                // Launch One-to-One or Group Chat Screen
                 Intent intent = new Intent(MainActivity.this, MessageActivity.class);
                 intent.putExtra("uid", "cometchat-uid-1");
                 startActivity(intent);
            }

            @Override
            public void onError(CometChatException e) {
                Log.e("Login", "Login failed: " + (e != null ? e.getMessage() : "Unknown error"));
            }
        });
    }
}

Running the Project

Once you’ve completed the setup, build and run the app:

gradle build

Required PermissionsEnsure you’ve added the necessary permissions in your AndroidManifest.xml and initialized CometChat in your Application class. :

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Next Steps

Enhance the User Experience

Advanced Customizations – Personalize the chat UI to align with your brand.

​User Interface Preview

​Key Components

​Step-by-Step Guide

​Use Case

​Step 1: Set Up Message Activity

​Layout

​Activity

​Step 2: Launch MessageActivity from Your App

​Running the Project

​Next Steps

​Enhance the User Experience

User Interface Preview

Key Components

Step-by-Step Guide

Use Case

Step 1: Set Up Message Activity

Layout

Activity

Step 2: Launch MessageActivity from Your App

Running the Project

Next Steps

Enhance the User Experience