Presenter Mode - CometChat Docs

Quick Reference - Start a presentation session:

// Configure presenter settings
let presenterSettings = new CometChatCalls.PresenterSettingsBuilder()
  .setIsPresenter(true) // false for viewer
  .enableDefaultLayout(true)
  .setCallEventListener(callListener)
  .build();

// Render presenter component
// <CometChatCalls.PresenterComponent presenterSettings={presenterSettings} callToken={callToken} />

Available via: SDK | UI Kits

Overview

The Presenter Mode feature allows developers to create a calling service experience in which:

There are one or more users who are presenting their video, audio and/or screen (Maximum 5)
Viewers who are consumers of that presentation. (They cannot send their audio, video or screen streams out).
The total number of presenters and viewers can go up to 100.
Features such as mute/unmute audio, show/hide camera capture, recording, etc. will be enabled only for the Presenter in this mode.
Other call participants will not get these features. Hence they act like passive viewers in the call.

Using this feature developers can create experiences such as:

All hands calls
Keynote speeches
Webinars
Talk shows
Online classes
and many more…

About this guide

This guide demonstrates how to start a presentation into an React Native application. Before you begin, we strongly recommend you read the calling setup guide. Before starting a call session you have to generate a call token.

Start Presentation Session

The most important class that will be used in the implementation is the PresentationSettings class. This class allows you to set the various parameters for the Presentation Mode. In order to set the various parameters of the PresentationSettings class, you need to use the PresentationSettingsBuilder class. Below are the various options available with the PresentationSettings class. You will need to set the User Type, There are 2 type of users in Presenter Mode, Presenter & Participant , You can set this PresentationSettingsBuilder by using the following method setIsPresenter(true/false) A basic example of how to start a Presentation:

JavaScript

let presenterSettings = new CometChatCalls.PresenterSettingsBuilder()
											.setIsPresenter(isPresenter)
                  	.enableDefaultLayout(defaultLayout)
                  	.setCallEventListener(callListener)
                  	.build();

render(){
 return(
    <View style={{flex:1}}>
				<CometChatCalls.PresenterComponent presenterSettings={presenterSettings} callToken={callToken} />
     </View>
 );
}

Listeners

Listeners can be added in two ways the first one is to use .setCallEventListener(listeners : OngoingCallListener) method in CallSettingsBuilder or PresenterSettingsBuilder class. The second way is to use CometChatCalls.addCallEventListener(name: string, callListener: OngoingCallListener) by this you can add multiple listeners and remove the specific listener by their name CometChatCalls.removeCallEventListener(name: string)

JavaScript

useEffect(() => {
  CometChatCalls.addCallEventListener("UNIQUE_ID", {
    onUserJoined: (user) => {
      console.log("user joined:", user);
    },
    onUserLeft: (user) => {
      console.log("user left:", user);
    },
    onUserListUpdated: (userList) => {
      console.log("user list:", userList);
    },
    onCallEnded: () => {
      console.log("Call ended");
    },
    onCallEndButtonPressed: () => {
      console.log("End Call button pressed");
    },
    onError: (error) => {
      console.log("Call Error: ", error);
    },
    onAudioModesUpdated: (audioModes) => {
      console.log("audio modes:", audioModes);
    },
    onUserMuted: (event) => {
      console.log("user muted:", event);
    },
  });
  return () => CometChatCalls.removeCallEventListener("UNIQUE_ID");
}, []);

Always remove call event listeners when the component unmounts using CometChatCalls.removeCallEventListener(listenerId). Failing to remove listeners can cause memory leaks and duplicate event handling.

onUserJoined Response

On Event — onUserJoined returns a user object when a participant joins the presentation:User Object:

Parameter	Type	Description	Sample Value
`uid`	string	Unique identifier of the user	`"cometchat-uid-6"`
`name`	string	Display name of the user	`"Ronald Jerry"`
`avatar`	string	URL to user’s avatar image	`"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-6.webp"`
`id`	string	Internal session participant ID	`"cd530243"`
`joinedAt`	string	Unix timestamp when user joined (as string)	`"1772095303043"`
`isVideoMuted`	boolean	Whether user’s video is muted	`true`
`isAudioMuted`	boolean	Whether user’s audio is muted	`false`
`isLocalUser`	boolean	Whether this is the local user	`false`

onUserLeft Response

On Event — onUserLeft returns a user object when a participant leaves the presentation:User Object:

Parameter	Type	Description	Sample Value
`uid`	string	Unique identifier of the user	`"cometchat-uid-6"`
`name`	string	Display name of the user	`"Ronald Jerry"`
`avatar`	string	URL to user’s avatar image	`"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-6.webp"`
`id`	string	Internal session participant ID	`"cd530243"`
`joinedAt`	string	Unix timestamp when user joined (as string)	`"1772095303043"`
`isVideoMuted`	boolean	Whether user’s video was muted	`true`
`isAudioMuted`	boolean	Whether user’s audio was muted	`false`

onUserListUpdated Response

On Event — onUserListUpdated returns an array of all current participants in the presentation:User Array:

Parameter	Type	Description	Sample Value
(array)	array	Array of user objects	See below ↓

User Object (each item in array):

Parameter	Type	Description	Sample Value
`uid`	string	Unique identifier of the user	`"cometchat-uid-7"`
`name`	string	Display name of the user	`"Henry Marino"`
`avatar`	string	URL to user’s avatar image	`"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-7.webp"`

onAudioModesUpdated Response

On Event — onAudioModesUpdated returns an array of available audio output modes:Audio Modes Array:

Parameter	Type	Description	Sample Value
(array)	array	Array of audio mode objects	See below ↓

Audio Mode Object (each item in array):

Parameter	Type	Description	Sample Value
`type`	string	Type of audio output device	`"SPEAKER"`
`selected`	boolean	Whether this mode is currently selected	`true`

onRecordingStarted Response

On Event — onRecordingStarted returns information about the user who started the recording:RecordingStartedBy Object:

Parameter	Type	Description	Sample Value
`uid`	string	Unique identifier of the user who started recording	`"cometchat-uid-7"`
`name`	string	Display name of the user	`"Henry Marino"`
`avatar`	string	URL to user’s avatar image	`"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-7.webp"`
`recordId`	string	Unique identifier for this recording session	`"noujausedimwfhwl"`
`id`	string	Internal session participant ID	`"042d0440"`
`isLocalUser`	string	Whether this is the local user (as string)	`"true"`
`isVideoMuted`	string	Whether user’s video is muted (as string)	`"true"`
`isAudioMuted`	string	Whether user’s audio is muted (as string)	`"false"`

onRecordingStopped Response

On Event — onRecordingStopped returns information about the user who stopped the recording:RecordingStoppedBy Object:

Parameter	Type	Description	Sample Value
`uid`	string	Unique identifier of the user who stopped recording	`"cometchat-uid-7"`
`name`	string	Display name of the user	`"Henry Marino"`
`avatar`	string	URL to user’s avatar image	`"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-7.webp"`
`id`	string	Internal session participant ID	`"042d0440"`
`isLocalUser`	string	Whether this is the local user (as string)	`"true"`
`isVideoMuted`	string	Whether user’s video is muted (as string)	`"true"`
`isAudioMuted`	string	Whether user’s audio is muted (as string)	`"false"`

The CometChatCallsEventsListener listener provides you with the below callback methods:

Callback Method	Description
onCallEnded()	This method is called when the call is successfully ended. The call details can be obtained from the `Call` object provided.
onCallEndButtonPressed()	This method is called when the user press end call button.
onUserJoined(user: RTCUser)	This method is called when any other user joins the call. The user details can be obtained from the `User` object provided.
onUserLeft(user: RTCUser)	This method is called when a user leaves the call. The details of the user can be obtained from the provided `User` object.
onUserListUpdated(users: Array<RTCUser>)	This method is triggered every time a participant joins or leaves the call providing the list of users active in the call
onAudioModesUpdated(devices: Array<AudioMode>)	This callback is triggered if any new audio output source is available or becomes unavailable.
onUserMuted(muteObj: RTCMutedUser)	This method is triggered when a user is muted in the ongoing call.
onRecordingStarted(user: RTCUser)	This method is triggered when a recording starts.
onRecordingStopped(user: RTCUser)	This method is triggered when a recording stops.
onError(e: CometChatException)	This method is called when there is some error in establishing the call.

Settings

The PresentationSettings class is the most important class when it comes to the implementation of the Calling feature. This is the class that allows you to customize the overall calling experience. The properties for the call/conference can be set using the PresentationSettingsBuilder class. This will eventually give you and object of the PresentationSettings class which you can pass to the joinPresentation() method to start the call. The mandatory parameters that are required to be present for any call/conference to work are:

Context - context of the activity/application
RelativeLayout - A RelativeLayout object in which the calling UI is loaded.

The options available for customization of calls are:

Parameter	Description
`setIsPresenter(isPresenter: boolean)`	If set to `true` user will join as the presenter. If set to `false` user will join as the viewer.
`enableDefaultLayout(defaultLayout: boolean)`	If set to `true` enables the default layout for handling the call operations. If set to `false` it hides the button layout and just displays the Call View. Default value = true
`showEndCallButton(showEndCallButton: boolean)`	If set to `true` it displays the EndCallButton in Button Layout. If set to `false` it hides the EndCallButton in Button Layout. Default value = true
`showEndCallButton(showEndCallButton: boolean)`	If set to `true` it displays the PauseVideoButton in Button Layout. If set to `false` it hides the PauseVideoButton in Button Layout. Default value = true
`showMuteAudioButton`(showMuteAudioButton: boolean)“	If set to `true` it displays the MuteAudioButton in Button Layout. If set to `false` it hides the MuteAudioButton in Button Layout. Default value = true
`showSwitchCameraButton`(showSwitchCameraButton: boolean)“	If set to `true` it displays the SwitchCameraButton in Button Layout. If set to `false` it hides the SwitchCameraButton in Button Layout. Default value = true
`showAudioModeButton`(showAudioModeButton: boolean)“	If set to `true` it displays the AudioModeButton in Button Layout. If set to `false` it hides the AudioModeButton in Button Layout. Default value = true
`setIsAudioOnlyCall(audioOnly: boolean)`	If set to `true`, the call will be strictly an audio call. If set to `false`, the call will be an audio-video call.Default value = false
`startWithAudioMuted(audioMuted: boolean)`	This ensures the call is started with the audio muted if set to true. Default value = false
`startWithVideoMuted(videoMuted: boolean)`	This ensures the call is started with the video paused if set to true. Default value = false
`startWithVideoMuted(videoMuted: boolean)`	If set to true it displays the Recording in Button Layout. if set to false it hides the Recording in Button Layout. Default value = false
`setDefaultAudioMode(audioMode: string)`	This method can be used if you wish to start the call with a specific audio mode. The available options are 1. CometChatCalls.AUDIO_MODE.SPEAKER = “SPEAKER” 2. CometChatCalls.AUDIO_MODE.EARPIECE = “EARPIECE” 3. CometChatCalls.AUDIO_MODE.BLUETOOTH = “BLUETOOTH” 4. CometChatCalls.AUDIO_MODE.HEADPHONES = “HEADPHONES”
`setEventListener(new CometChatCallsEventsListener())`	The `CometChatCallsEventsListener` listener provides you callbacks

In case you wish to achieve a completely customised UI for the Calling experience, you can do so by embedding default android buttons to the screen as per your requirement and then use the below methods to achieve different functionalities for the embedded buttons. For the use case where you wish to align your own custom buttons and not use the default layout provided by CometChat you can embed the buttons in your layout and use the below methods to perform the corresponding operations:

Best Practices

Set user type correctly

Always explicitly set setIsPresenter(true) for presenters and setIsPresenter(false) for viewers. Viewers cannot send audio, video, or screen streams — this is enforced by the SDK, not just the UI.

Limit presenters to 5

Presenter Mode supports a maximum of 5 concurrent presenters. If your app allows dynamic role switching, enforce this limit in your logic before calling setIsPresenter(true) for additional users.

Clean up listeners on component unmount

Always remove call event listeners in your component’s cleanup function (e.g., the return function of useEffect). Orphaned listeners can cause memory leaks and duplicate event handling.

Generate call tokens just before use

Call tokens are session-specific and time-limited. Generate them right before starting the presentation session rather than caching them for extended periods.

Troubleshooting

Viewer can send audio/video

Verify that setIsPresenter(false) is set for viewer participants. If a viewer is incorrectly set as a presenter, they will have access to media controls.

Presentation UI does not render

Ensure the CometChatCalls.PresenterComponent is wrapped in a View with flex: 1 or explicit dimensions. Also confirm that both presenterSettings and callToken props are provided and not null.

Listeners not firing

Check that the listener is registered before the presentation session starts. If using addCallEventListener, ensure the listenerId is unique and hasn’t been overwritten. Also verify the Calls SDK has been initialized via CometChatCalls.init().

Maximum participant limit reached

Presenter Mode supports up to 100 total participants (presenters + viewers). If users can’t join, check the current participant count in your session.

Next Steps

Call Session

Start and manage standard call sessions with full configuration options

Recording

Record presentation sessions for playback and compliance

Video View Customisation

Customize the main video container and participant tiles

Calls SDK Setup

Install dependencies, configure permissions, and initialize the Calls SDK

​Overview

​About this guide

​Start Presentation Session

​Listeners

​Settings

​Best Practices

​Troubleshooting

​Next Steps

Call Session

Recording

Video View Customisation

Calls SDK Setup

Overview

About this guide

Start Presentation Session

Listeners

Settings

Best Practices

Troubleshooting

Next Steps