Building A Tab-Based Messaging UI

AI Integration Quick Reference

Field	Value
Components	`CometChatConversations`, `CometChatCallLogs`, `CometChatUsers`, `CometChatGroups`
Layout	Tabbed bottom navigation (Chats, Calls, Users, Groups)
Prerequisite	Complete Kotlin Integration or Jetpack Compose Integration Steps 1–3 first
Pattern	Full-featured messaging app with multiple sections

This guide builds a tabbed messaging UI — Chats, Calls, Users, and Groups tabs via bottom navigation, with each tab loading its CometChat component. This assumes you’ve already completed the integration guide for your chosen UI toolkit (project created, dependencies installed, init + login working).

What You’re Building

Two sections working together:

Bottom navigation bar — switches between Chats, Calls, Users, and Groups
Content area — renders the CometChat component for the active tab

Kotlin (XML Views)
Jetpack Compose

This uses Android’s BottomNavigationView with Fragments: TabbedActivity hosts the navigation and fragment container, user taps a tab, the corresponding Fragment loads.

This uses Material 3 NavigationBar with Compose state: a single composable manages the selected tab and renders the corresponding CometChat component.

Step 1: Set Up the Tabbed Screen

Kotlin (XML Views)
Jetpack Compose

Create a new Activity called TabbedActivity with BottomNavigationView.Layout — activity_tabbed.xml:

activity_tabbed.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <FrameLayout
        android:id="@+id/fragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomNavigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:menu="@menu/bottom_nav_menu"/>

</LinearLayout>

Menu — res/menu/bottom_nav_menu.xml:

bottom_nav_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/nav_chats" android:icon="@drawable/ic_chats" android:title="Chats"/>
    <item android:id="@+id/nav_call_logs" android:icon="@drawable/ic_calls" android:title="Calls"/>
    <item android:id="@+id/nav_users" android:icon="@drawable/ic_user" android:title="Users"/>
    <item android:id="@+id/nav_groups" android:icon="@drawable/ic_group" android:title="Groups"/>
</menu>

Activity — TabbedActivity.kt:

TabbedActivity.kt

import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.fragment.app.Fragment
import com.google.android.material.bottomnavigation.BottomNavigationView

class TabbedActivity : AppCompatActivity() {

    private lateinit var bottomNav: BottomNavigationView

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

        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val bars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(bars.left, bars.top, bars.right, bars.bottom)
            insets
        }

        bottomNav = findViewById(R.id.bottomNavigationView)

        bottomNav.setOnItemSelectedListener { item ->
            replaceFragment(
                when (item.itemId) {
                    R.id.nav_chats -> ChatsFragment()
                    R.id.nav_call_logs -> CallLogsFragment()
                    R.id.nav_users -> UsersFragment()
                    R.id.nav_groups -> GroupsFragment()
                    else -> ChatsFragment()
                }
            )
            true
        }

        if (savedInstanceState == null) {
            replaceFragment(ChatsFragment())
        }
    }

    private fun replaceFragment(fragment: Fragment) {
        supportFragmentManager.beginTransaction()
            .replace(R.id.fragmentContainer, fragment)
            .commit()
    }
}

Create a TabbedScreen composable with NavigationBar:

TabbedScreen.kt

import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.size
import androidx.compose.material3.Icon
import androidx.compose.material3.NavigationBar
import androidx.compose.material3.NavigationBarItem
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.unit.dp
import com.cometchat.chat.models.Group
import com.cometchat.chat.models.User
import com.cometchat.uikit.compose.presentation.calllogs.ui.CometChatCallLogs
import com.cometchat.uikit.compose.presentation.conversations.ui.CometChatConversations
import com.cometchat.uikit.compose.presentation.groups.ui.CometChatGroups
import com.cometchat.uikit.compose.presentation.users.ui.CometChatUsers

enum class Tab(val label: String, val iconRes: Int) {
    Chats("Chats", R.drawable.ic_chats),
    Calls("Calls", R.drawable.ic_calls),
    Users("Users", R.drawable.ic_users),
    Groups("Groups", R.drawable.ic_groups)
}

@Composable
fun TabbedScreen(
    onUserClick: (User) -> Unit = {},
    onGroupClick: (Group) -> Unit = {}
) {
    var selectedTab by rememberSaveable { mutableStateOf(Tab.Chats) }

    Scaffold(
        bottomBar = {
            NavigationBar {
                Tab.entries.forEach { tab ->
                    NavigationBarItem(
                        selected = selectedTab == tab,
                        onClick = { selectedTab = tab },
                        icon = {
                            Icon(
                                painter = painterResource(tab.iconRes),
                                contentDescription = tab.label,
                                modifier = Modifier.size(32.dp)
                            )
                        },
                        label = { Text(tab.label) }
                    )
                }
            }
        }
    ) { paddingValues ->
        Box(
            modifier = Modifier
                .fillMaxSize()
                .padding(paddingValues)
        ) {
            when (selectedTab) {
                Tab.Chats -> CometChatConversations(
                    modifier = Modifier.fillMaxSize(),
                    title = "Chats",
                    onItemClick = { conversation ->
                        when (val entity = conversation.conversationWith) {
                            is User -> onUserClick(entity)
                            is Group -> onGroupClick(entity)
                        }
                    }
                )
                Tab.Calls -> CometChatCallLogs(
                    modifier = Modifier.fillMaxSize()
                )
                Tab.Users -> CometChatUsers(
                    modifier = Modifier.fillMaxSize(),
                    onItemClick = { user -> onUserClick(user) }
                )
                Tab.Groups -> CometChatGroups(
                    modifier = Modifier.fillMaxSize(),
                    onItemClick = { group -> onGroupClick(group) }
                )
            }
        }
    }
}

Step 2: Create Tab Content

Kotlin (XML Views)
Jetpack Compose

Create a Fragment for each tab. Each Fragment inflates a layout containing the corresponding CometChat component.ChatsFragment:

ChatsFragment.kt

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment

class ChatsFragment : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_chats, container, false)
    }
}

fragment_chats.xml

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

    <com.cometchat.uikit.kotlin.presentation.conversations.ui.CometChatConversations
        android:id="@+id/conversations"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

CallLogsFragment:

CallLogsFragment.kt

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment

class CallLogsFragment : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_call_logs, container, false)
    }
}

fragment_call_logs.xml

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

    <com.cometchat.uikit.kotlin.presentation.calllogs.ui.CometChatCallLogs
        android:id="@+id/call_logs"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

UsersFragment:

UsersFragment.kt

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment

class UsersFragment : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_users, container, false)
    }
}

fragment_users.xml

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

    <com.cometchat.uikit.kotlin.presentation.users.ui.CometChatUsers
        android:id="@+id/users"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

GroupsFragment:

GroupsFragment.kt

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment

class GroupsFragment : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment_groups, container, false)
    }
}

fragment_groups.xml

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

    <com.cometchat.uikit.kotlin.presentation.groups.ui.CometChatGroups
        android:id="@+id/groups"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

Download the navigation icons from the CometChat UI Kit repository and place them in your res/drawable/ directory.

No separate files needed — the tab content is already defined inline in the TabbedScreen composable above. Each when branch renders the corresponding CometChat component directly.

Step 3: Launch the Tabbed Screen

Kotlin (XML Views)
Jetpack Compose

Launch TabbedActivity from your MainActivity after successful login:

MainActivity.kt

private fun loginUser() {
    CometChatUIKit.login("cometchat-uid-1", object : CometChat.CallbackListener<User>() {
        override fun onSuccess(user: User) {
            Log.d(TAG, "Login successful: ${user.uid}")

            // Launch Tab-Based Chat Experience
            startActivity(Intent(this@MainActivity, TabbedActivity::class.java))
        }

        override fun onError(e: CometChatException) {
            Log.e(TAG, "Login failed: ${e.message}")
        }
    })
}

Render TabbedScreen from your MainActivity after successful login:

MainActivity.kt

setContent {
    when {
        error != null -> {
            Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
                Text(error ?: "Unknown error")
            }
        }
        !isReady -> {
            Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
                CircularProgressIndicator()
            }
        }
        else -> {
            TabbedScreen(
                onUserClick = { user ->
                    // Navigate to message screen with user
                },
                onGroupClick = { group ->
                    // Navigate to message screen with group
                }
            )
        }
    }
}

Step 4: Register Activity & Permissions

Kotlin (XML Views)
Jetpack Compose

Add the activity to your AndroidManifest.xml:

AndroidManifest.xml

<application ...>
    <activity android:name=".TabbedActivity" />
</application>

No additional activities needed — everything runs inside your existing MainActivity.

Ensure you’ve added the required permissions in your AndroidManifest.xml:

AndroidManifest.xml

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

For call features, also add:

AndroidManifest.xml

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

Next Steps

Components Overview

Explore all available UI Kit components and their customization options

Theming

Customize colors, fonts, and styles to match your brand

Integration

Back to the main integration guide

Feature Guides

Add capabilities like threaded messages, blocking, and group management

​What You’re Building

​Step 1: Set Up the Tabbed Screen

​Step 2: Create Tab Content

​Step 3: Launch the Tabbed Screen

​Step 4: Register Activity & Permissions

​Next Steps

Components Overview

Theming

Integration

Feature Guides

What You’re Building

Step 1: Set Up the Tabbed Screen

Step 2: Create Tab Content

Step 3: Launch the Tabbed Screen

Step 4: Register Activity & Permissions

Next Steps