Cometchat Flutter Calls

CometChat Flutter UIKit — Calls

Voice and video calling for 1:1 and group conversations. Call functionality is built into cometchat_chat_uikit — no separate package needed.

Import

import 'package:cometchat_chat_uikit/cometchat_chat_uikit.dart';
import 'package:cometchat_chat_uikit/cometchat_calls_uikit.dart';

The first import gives you chat components. The second gives you call-specific types.

Rule: CALLS_INIT_AFTER_CHAT_INIT

CometChatUIKitCalls.init() MUST be called after CometChatUIKit.init() completes. The calls SDK needs the chat SDK's auth context.

// ✅ CORRECT — calls init after chat init
CometChatUIKit.init(
  uiKitSettings: settings,
  onSuccess: (_) {
    CometChatUIKitCalls.init(appId, region,
      onSuccess: (_) => debugPrint('Calls SDK ready'),
      onError: (e) => debugPrint('Calls init failed: ${e.message}'),
    );
  },
);

// ❌ WRONG — parallel init causes auth token null
CometChatUIKit.init(uiKitSettings: settings);
CometChatUIKitCalls.init(appId, region); // Race condition

Rule: SINGLE_CALLS_INIT

CometChatUIKitCalls.init() must be called exactly once per app lifecycle. Calling it again after logout + re-login can cause "session already started" errors.

Rule: CALLS_REINIT_AFTER_LOGOUT

After CometChatUIKit.logout(), the calls SDK session is invalidated. On the next login, CometChatUIKitCalls.init() must be called again.

Architecture

call_ui/src/
├── call_buttons/          # Voice/video call buttons (CallButtonsBloc)
├── incoming_call/         # Incoming call screen (IncomingCallBloc)
├── outgoing_call/         # Outgoing call screen (OutgoingCallBloc)
├── ongoing_call/          # Active call screen — WebRTC (OngoingCallBloc)
├── call_logs/             # Call history list (CallLogsBloc + Clean Arch)
├── call_operations/       # Shared clean architecture (DI, use cases, repos)
├── call_bubble/           # Call message bubble in chat
├── call_settings/         # CometChatUIKitCalls, CallNavigationContext
├── native_call_kit/       # iOS CallKit / Android ConnectionService
├── utils/                 # CallUtils, CallStateService, CallPermissions
├── call_event_service.dart  # Centralized call event handling
└── calling_configuration.dart  # Top-level config object

Components

CometChatCallButtons

Voice and video call buttons. Typically placed in CometChatMessageHeader's trailing view or standalone.

CometChatCallButtons(
  user: user,           // For 1:1 calls
  group: group,         // For group calls (meetings)
  hideVoiceCallButton: false,
  hideVideoCallButton: false,
  voiceCallIcon: Icon(Icons.call),
  videoCallIcon: Icon(Icons.videocam),
  callButtonsStyle: CometChatCallButtonsStyle(
    voiceCallIconColor: colorPalette.iconPrimary,
    videoCallIconColor: colorPalette.iconPrimary,
  ),
  outgoingCallConfiguration: CometChatOutgoingCallConfiguration(
    outgoingCallStyle: CometChatOutgoingCallStyle(...),
  ),
)

Call buttons are built into CometChatMessageHeader by default:

CometChatMessageHeader(
  user: user,
  group: group,
  hideVoiceCallButton: false,
  hideVideoCallButton: false,
)

CometChatIncomingCall

Displays when the logged-in user receives a call. Supports accept/decline with custom views.

CometChatIncomingCall(
  call: call,                    // Required — the active Call object
  user: callerUser,              // Caller info for display
  onAccept: (ctx, call) { },
  onDecline: (ctx, call) { },
  disableSoundForCalls: false,
  customSoundForCalls: 'assets/ringtone.mp3',
  incomingCallStyle: CometChatIncomingCallStyle(
    backgroundColor: colorPalette.background3,
    acceptButtonColor: colorPalette.success,
    declineButtonColor: colorPalette.error,
  ),
  // Custom view slots
  titleView: (ctx, call) => Text('Custom Title'),
  subTitleView: (ctx, call) => Text('Custom Subtitle'),
  leadingView: (ctx, call) => Icon(Icons.call),
  trailingView: (ctx, call) => CometChatAvatar(image: user.avatar),
)

CometChatOutgoingCall

Displays when the logged-in user initiates a call.

CometChatOutgoingCall(
  call: call,
  user: receiverUser,
  outgoingCallStyle: CometChatOutgoingCallStyle(
    backgroundColor: colorPalette.background1,
  ),
)

CometChatOngoingCall

The active call screen with WebRTC video/audio. Rendered after a call is accepted.

CometChatOngoingCall(
  callSettingsBuilder: sessionSettingsBuilder,
  sessionId: call.sessionId,
  callWorkFlow: CallWorkFlow.directCalling,
)

CometChatCallLogs

Scrollable list of call history. Clean Architecture + BLoC with CallLogsServiceLocator.

CometChatCallLogs(
  onItemClick: (callLog) { /* Navigate or initiate call */ },
  callLogsStyle: CallLogsStyle(backgroundColor: colorPalette.background1),
)

CometChatCallBubble

Message bubble for call events in the message list. Automatically rendered for call-type messages.

CallingConfiguration

Top-level configuration object bundling all call component configs:

CallingConfiguration(
  outgoingCallConfiguration: CometChatOutgoingCallConfiguration(...),
  incomingCallConfiguration: CometChatIncomingCallConfiguration(...),
  callButtonsConfiguration: CallButtonsConfiguration(...),
  groupSessionSettingsBuilder: sessionSettingsBuilder,
)

CometChatUIKitCalls API

Call Flow — 1:1 Direct Call

Caller                              Receiver
  |-- CometChatCallButtons tap ------->|
  |-- initiateCall(Call) ------------->|
  |-- CometChatOutgoingCall shown ---->|
  |                                    |-- CometChatIncomingCall shown
  |                                    |-- acceptCall(sessionId)
  |<-- onOutgoingCallAccepted ---------|
  |-- generateToken(sessionId) ------->|
  |-- startSession(token, settings) -->|
  |-- CometChatOngoingCall shown ----->|-- CometChatOngoingCall shown
  |-- endSession() ------------------>|-- endSession()

Golden Path — Messages Screen with Calls

Scaffold(
  resizeToAvoidBottomInset: false,
  appBar: CometChatMessageHeader(
    user: user,
    group: group,
    onBack: () => Navigator.pop(context),
    hideVoiceCallButton: false,
    hideVideoCallButton: false,
  ),
  body: Column(
    children: [
      Expanded(child: CometChatMessageList(user: user, group: group)),
      CometChatMessageComposer(user: user, group: group),
    ],
  ),
)

BLoC Events

CallButtonsBloc

IncomingCallBloc

OutgoingCallBloc

OngoingCallBloc

CallLogsBloc

Gotchas

• CometChatUIKitCalls.init() must happen AFTER CometChatUIKit.init() — parallel init causes "auth token null".
• After logout, the calls SDK session is invalidated. Re-init required on next login.
• startSession on Android can return null with a 5-second timeout and no error feedback. Known platform issue.
• SessionType.audio is ignored on Android in some SDK versions — always opens with video. Known external SDK bug.
• Group calls use CometChat.Group not CometChat.User on CometChatCallButtons.
• Incoming call handling must be global (mounted at app root level) so calls ring on every screen.
• CallOperationsServiceLocator must be initialized before using call BLoCs directly. UIKit widgets handle this automatically.
• After logout, call CallOperationsServiceLocator.instance.reset() to clean up.
• On iOS, CallKit integration via native_call_kit shows the native call UI. Ensure Info.plist has the voip background mode.
• On Android, the ongoing call foreground service shows a notification during active calls. Launched automatically by startSession.

Anti-Patterns

// ❌ WRONG — init calls SDK before chat SDK
CometChatUIKitCalls.init(appId, region);
CometChatUIKit.init(uiKitSettings: settings);

// ✅ CORRECT — calls init in chat init's onSuccess
CometChatUIKit.init(
  uiKitSettings: settings,
  onSuccess: (_) {
    CometChatUIKitCalls.init(appId, region);
  },
);

// ❌ WRONG — not handling incoming calls globally
CometChatIncomingCall(call: call, user: user) // Only on messages screen

// ✅ CORRECT — mount incoming call overlay at app root
MaterialApp(
  builder: (context, child) {
    return Stack(children: [child!, /* Global incoming call listener */]);
  },
)

Checklist

• CometChatUIKitCalls.init() called after CometChatUIKit.init() completes
• Incoming call handling is global (app root level), not per-screen
• Camera + microphone permissions handled (automatic via CallPermissions)
• resizeToAvoidBottomInset: false on any Scaffold with call UI
• Call buttons visible in CometChatMessageHeader (default) or standalone
• After logout, calls SDK re-initialized on next login
• Android: minSdk = 26, ProGuard rules for com.cometchat.**
• iOS: voip background mode in Info.plist for CallKit
• Theme cached in didChangeDependencies(), not build()
• SDK listeners cleaned up in dispose()