Events & Callbacks

Handle user interaction events, selection mode, and global UI Kit events.

The UI Kit provides two levels of event handling: component-level callbacks set directly on a component, and global events via the CometChatEvents singleton using Kotlin SharedFlow.

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Component-Level Callbacks

Click Callbacks

Kotlin (XML Views)

conversations.setOnItemClick { conversation ->
    // Navigate to chat screen
}

conversations.setOnItemLongClick { conversation ->
    // Show context menu
}

conversations.setOnBackPress {
    // Handle back navigation
}

conversations.setOnSearchClick {
    // Open search
}

conversations.setOnError { exception ->
    Log.e("Conversations", "Error: ${exception.message}")
}

conversations.setOnLoad { list ->
    Log.d("Conversations", "Loaded ${list.size} conversations")
}

conversations.setOnEmpty {
    Log.d("Conversations", "No conversations")
}

Jetpack Compose

CometChatConversations(
    onItemClick = { conversation ->
        // Navigate to chat screen
    },
    onItemLongClick = { conversation ->
        // Show context menu
    },
    onBackPress = {
        // Handle back navigation
    },
    onSearchClick = {
        // Open search
    },
    onError = { exception ->
        Log.e("Conversations", "Error: ${exception.message}")
    },
    onLoad = { list ->
        Log.d("Conversations", "Loaded ${list.size} conversations")
    },
    onEmpty = {
        Log.d("Conversations", "No conversations")
    }
)

---

Selection Mode

Enable single or multi-select on list components:

Kotlin (XML Views)

// Enable multi-select mode
conversations.setSelectionMode(UIKitConstants.SelectionMode.MULTIPLE)

// Listen for selection changes
conversations.setOnSelection { selectedList ->
    updateToolbar(selectedList.size)
}

// Get selected items
val selected = conversations.getSelectedConversations()

// Clear selection
conversations.clearSelection()

Jetpack Compose

CometChatConversations(
    selectionMode = UIKitConstants.SelectionMode.MULTIPLE,
    onSelection = { selectedList ->
        updateToolbar(selectedList.size)
    }
)

---

Global Events (CometChatEvents)

Global events are emitted by UI Kit components when actions happen anywhere in the app. They use Kotlin SharedFlow for reactive, type-safe event distribution. Subscribe from any coroutine scope.

Event Flows

Flow	Sealed Class	Fires When
CometChatEvents.messageEvents	CometChatMessageEvent	Messages sent, edited, deleted, reactions, typing
CometChatEvents.callEvents	CometChatCallEvent	Calls initiated, accepted, rejected, ended
CometChatEvents.conversationEvents	CometChatConversationEvent	Conversations deleted or updated
CometChatEvents.groupEvents	CometChatGroupEvent	Groups created, updated, members changed
CometChatEvents.userEvents	CometChatUserEvent	Users blocked/unblocked
CometChatEvents.uiEvents	CometChatUIEvent	UI-level events (panels, dialogs)

Subscribing to Events

import com.cometchat.uikit.core.events.CometChatEvents
import com.cometchat.uikit.core.events.CometChatMessageEvent

// Subscribe in a ViewModel or lifecycle-aware scope
viewModelScope.launch {
    CometChatEvents.messageEvents.collect { event ->
        when (event) {
            is CometChatMessageEvent.MessageSent -> {
                // Handle sent message: event.message, event.status
            }
            is CometChatMessageEvent.MessageDeleted -> {
                // Handle deleted message: event.message
            }
            is CometChatMessageEvent.MessageEdited -> {
                // Handle edited message: event.message
            }
            is CometChatMessageEvent.ReactionAdded -> {
                // Handle reaction: event.event
            }
            else -> { /* other message events */ }
        }
    }
}

Emitting Events

// Emit from anywhere — thread-safe
CometChatEvents.emitMessageEvent(
    CometChatMessageEvent.MessageSent(message, MessageStatus.SUCCESS)
)

CometChatEvents.emitCallEvent(
    CometChatCallEvent.OutgoingCall(call)
)

CometChatEvents.emitConversationEvent(
    CometChatConversationEvent.ConversationDeleted(conversation)
)

Key Event Types

Message Events:

Event	Data
MessageSent	message, status
MessageEdited	message, status
MessageDeleted	message
MessageRead	message
ReactionAdded / ReactionRemoved	event (ReactionEvent)
TypingStarted / TypingEnded	indicator (TypingIndicator)
MessagesDelivered / MessagesRead	receipt (MessageReceipt)

Call Events:

Event	Data
OutgoingCall	call
CallAccepted	call
CallRejected	call
CallEnded	call

Conversation Events:

Event	Data
ConversationDeleted	conversation
ConversationUpdated	conversation

---

Component vs Global Events

Aspect	Component Callbacks	Global Events
Scope	Single component instance	App-wide
Registration	setOnItemClick {} or composable parameter	CometChatEvents.*.collect {}
Use case	Handle user interaction on a specific screen	Cross-component coordination
Example	Tap a conversation → navigate	Message sent → update conversation list

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Related

• Events Reference — Full list of all event types.
• Customization Overview — SDK Listeners vs UIKit Events distinction.