Participant Management

Manage participants during a call with actions like muting, pausing video, and pinning. These features help maintain order in group calls and highlight important speakers.

By default, all participants who join a call have moderator access and can perform these actions. Implementing role-based moderation (e.g., restricting actions to hosts only) is the responsibility of the app developer based on their use case.

Mute a Participant

Mute a specific participant’s audio. This affects the participant for all users in the call.

Swift
Objective-C

guard let uid = participant.uid else { return }
CallSession.shared.muteParticipant(participantId: uid)

if (participant.uid) {
    [[CallSession shared] muteParticipantWithParticipantId:participant.uid];
}

Pause Participant Video

Pause a specific participant’s video. This affects the participant for all users in the call.

Swift
Objective-C

guard let uid = participant.uid else { return }
CallSession.shared.pauseParticipantVideo(participantId: uid)

if (participant.uid) {
    [[CallSession shared] pauseParticipantVideoWithParticipantId:participant.uid];
}

Pin a Participant

Pin a participant to keep them prominently displayed regardless of who is speaking. Useful for keeping focus on a presenter or important speaker.

Swift
Objective-C

// Pin a participant
CallSession.shared.pinParticipant(participantId: "PARTICIPANT_UID", type: "pin")

// Unpin (returns to automatic speaker highlighting)
CallSession.shared.unpinParticipant()

// Pin a participant
[[CallSession shared] pinParticipantWithParticipantId:@"PARTICIPANT_UID" type:@"pin"];

// Unpin (returns to automatic speaker highlighting)
[[CallSession shared] unpinParticipant];

Pinning a participant only affects your local view. Other participants can pin different users independently.

Listen for Participant Events

Monitor participant state changes using ParticipantEventListener:

Swift
Objective-C

class CallViewController: UIViewController, ParticipantEventListener {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        CallSession.shared.addParticipantEventListener(self)
    }
    
    deinit {
        CallSession.shared.removeParticipantEventListener(self)
    }
    
    func onParticipantJoined(participant: Participant) {
        print("\(participant.name ?? "") joined the call")
        updateParticipantList()
    }

    func onParticipantLeft(participant: Participant) {
        print("\(participant.name ?? "") left the call")
        updateParticipantList()
    }

    func onParticipantListChanged(participants: [Participant]) {
        print("Participant count: \(participants.count)")
        refreshParticipantList(participants)
    }

    func onParticipantAudioMuted(participant: Participant) {
        print("\(participant.name ?? "") was muted")
        updateMuteIndicator(participant, muted: true)
    }

    func onParticipantAudioUnmuted(participant: Participant) {
        print("\(participant.name ?? "") was unmuted")
        updateMuteIndicator(participant, muted: false)
    }

    func onParticipantVideoPaused(participant: Participant) {
        print("\(participant.name ?? "") video paused")
        showParticipantAvatar(participant)
    }

    func onParticipantVideoResumed(participant: Participant) {
        print("\(participant.name ?? "") video resumed")
        showParticipantVideo(participant)
    }

    func onDominantSpeakerChanged(participant: Participant) {
        print("\(participant.name ?? "") is now speaking")
        highlightActiveSpeaker(participant)
    }

    // Other callbacks...
    func onParticipantHandRaised(participant: Participant) {}
    func onParticipantHandLowered(participant: Participant) {}
    func onParticipantStartedScreenShare(participant: Participant) {}
    func onParticipantStoppedScreenShare(participant: Participant) {}
    func onParticipantStartedRecording(participant: Participant) {}
    func onParticipantStoppedRecording(participant: Participant) {}
}

@interface CallViewController () <ParticipantEventListener>
@end

@implementation CallViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [[CallSession shared] addParticipantEventListener:self];
}

- (void)dealloc {
    [[CallSession shared] removeParticipantEventListener:self];
}

- (void)onParticipantJoinedWithParticipant:(Participant *)participant {
    NSLog(@"%@ joined the call", participant.name);
    [self updateParticipantList];
}

- (void)onParticipantLeftWithParticipant:(Participant *)participant {
    NSLog(@"%@ left the call", participant.name);
    [self updateParticipantList];
}

- (void)onParticipantListChangedWithParticipants:(NSArray<Participant *> *)participants {
    NSLog(@"Participant count: %lu", (unsigned long)participants.count);
    [self refreshParticipantList:participants];
}

- (void)onParticipantAudioMutedWithParticipant:(Participant *)participant {
    NSLog(@"%@ was muted", participant.name);
}

- (void)onParticipantAudioUnmutedWithParticipant:(Participant *)participant {
    NSLog(@"%@ was unmuted", participant.name);
}

- (void)onDominantSpeakerChangedWithParticipant:(Participant *)participant {
    NSLog(@"%@ is now speaking", participant.name);
}

// Other callbacks...

@end

Participant Object

The Participant object contains information about each call participant:

Property	Type	Description
`uid`	`String?`	CometChat user ID — the identifier every moderator action takes
`name`	`String?`	Display name
`avatar`	`String?`	URL of avatar image
`mid`	`String?`	Media ID for this call session
`state`	`String?`	Participant state as reported by the server
`isJoined`	`Bool?`	Whether the participant is currently joined
`joinedAt`	`Int?`	Join timestamp
`leftAt`	`Int?`	Leave timestamp
`deviceID`	`String?`	Device identifier
`totalAudioMinutes`	`Double?`	Audio minutes consumed
`totalVideoMinutes`	`Double?`	Video minutes consumed
`totalDurationInMinutes`	`Double?`	Total session minutes

Every property is Optional. Participant carries no mute / video / pin / hand-raise / screen-share flags, and the SDK exposes no getter for them — track that state in your own app from the participant events. Because the events fire only on change, a client that joins late cannot recover state that was already in effect.

Hide Participant List Button

To hide the participant list button in the call UI:

Swift
Objective-C

let sessionSettings = CometChatCalls.sessionSettingsBuilder
    .hideParticipantListButton(true)
    .build()

SessionSettings *sessionSettings = [[[CometChatCalls sessionSettingsBuilder]
    hideParticipantListButton:YES]
    build];

Overview

Getting Started

Call Session

Features

Advanced

Migration Guide

Resources

Mute a Participant

Pause Participant Video

Pin a Participant

Listen for Participant Events

Participant Object

Hide Participant List Button

​Mute a Participant

​Pause Participant Video

​Pin a Participant

​Listen for Participant Events

​Participant Object

​Hide Participant List Button

Mute a Participant

Pause Participant Video

Pin a Participant

Listen for Participant Events

Participant Object

Hide Participant List Button