Participant Event Listener

Monitor participant activities with ParticipantEventListener. This listener provides callbacks for participant join/leave events, audio/video state changes, hand raise actions, screen sharing, recording, and more.

Prerequisites

• An active call session
• Access to the CallSession instance

Register Listener

Register a ParticipantEventListener to receive participant event callbacks:

Kotlin

val callSession = CallSession.getInstance()

callSession.addParticipantEventListener(this, object : ParticipantEventListener() {
    override fun onParticipantJoined(participant: Participant) {
        Log.d(TAG, "${participant.name} joined the call")
    }

    override fun onParticipantLeft(participant: Participant) {
        Log.d(TAG, "${participant.name} left the call")
    }

    override fun onParticipantListChanged(participants: List<Participant>) {
        Log.d(TAG, "Participant list updated: ${participants.size} participants")
    }

    // Additional callbacks...
})

Java

CallSession callSession = CallSession.getInstance();

callSession.addParticipantEventListener(this, new ParticipantEventListener() {
    @Override
    public void onParticipantJoined(Participant participant) {
        Log.d(TAG, participant.getName() + " joined the call");
    }

    @Override
    public void onParticipantLeft(Participant participant) {
        Log.d(TAG, participant.getName() + " left the call");
    }

    @Override
    public void onParticipantListChanged(List<Participant> participants) {
        Log.d(TAG, "Participant list updated: " + participants.size() + " participants");
    }

    // Additional callbacks...
});

The listener is automatically removed when the LifecycleOwner (Activity/Fragment) is destroyed, preventing memory leaks.

---

Participant Object

The Participant object contains information about a call participant:

Property	Type	Description
uid	String	Unique identifier of the participant
name	String	Display name of the participant
avatar	String	Avatar URL of the participant
isAudioMuted	Boolean	Whether audio is muted
isVideoPaused	Boolean	Whether video is paused
isHandRaised	Boolean	Whether hand is raised
isScreenSharing	Boolean	Whether screen is being shared

---

Callbacks

onParticipantJoined

Triggered when a new participant joins the call.

Kotlin

override fun onParticipantJoined(participant: Participant) {
    Log.d(TAG, "${participant.name} joined the call")
    // Show join notification
    // Update participant grid
}

Java

@Override
public void onParticipantJoined(Participant participant) {
    Log.d(TAG, participant.getName() + " joined the call");
    // Show join notification
    // Update participant grid
}

Use Cases:

• Display join notification/toast
• Update participant count
• Play join sound

---

onParticipantLeft

Triggered when a participant leaves the call.

Kotlin

override fun onParticipantLeft(participant: Participant) {
    Log.d(TAG, "${participant.name} left the call")
    // Show leave notification
    // Update participant grid
}

Java

@Override
public void onParticipantLeft(Participant participant) {
    Log.d(TAG, participant.getName() + " left the call");
    // Show leave notification
    // Update participant grid
}

Use Cases:

• Display leave notification
• Update participant count
• Play leave sound

---

onParticipantListChanged

Triggered when the participant list changes (join, leave, or any update).

Kotlin

override fun onParticipantListChanged(participants: List<Participant>) {
    Log.d(TAG, "Participants: ${participants.size}")
    // Update participant list UI
    updateParticipantGrid(participants)
}

Java

@Override
public void onParticipantListChanged(List<Participant> participants) {
    Log.d(TAG, "Participants: " + participants.size());
    // Update participant list UI
    updateParticipantGrid(participants);
}

Use Cases:

• Refresh participant list/grid
• Update participant count badge
• Sync local state with server

---

onParticipantAudioMuted

Triggered when a participant mutes their audio.

Kotlin

override fun onParticipantAudioMuted(participant: Participant) {
    Log.d(TAG, "${participant.name} muted their audio")
    // Show muted indicator on participant tile
}

Java

@Override
public void onParticipantAudioMuted(Participant participant) {
    Log.d(TAG, participant.getName() + " muted their audio");
    // Show muted indicator on participant tile
}

---

onParticipantAudioUnmuted

Triggered when a participant unmutes their audio.

Kotlin

override fun onParticipantAudioUnmuted(participant: Participant) {
    Log.d(TAG, "${participant.name} unmuted their audio")
    // Hide muted indicator on participant tile
}

Java

@Override
public void onParticipantAudioUnmuted(Participant participant) {
    Log.d(TAG, participant.getName() + " unmuted their audio");
    // Hide muted indicator on participant tile
}

---

onParticipantVideoPaused

Triggered when a participant pauses their video.

Kotlin

override fun onParticipantVideoPaused(participant: Participant) {
    Log.d(TAG, "${participant.name} paused their video")
    // Show avatar or placeholder instead of video
}

Java

@Override
public void onParticipantVideoPaused(Participant participant) {
    Log.d(TAG, participant.getName() + " paused their video");
    // Show avatar or placeholder instead of video
}

---

onParticipantVideoResumed

Triggered when a participant resumes their video.

Kotlin

override fun onParticipantVideoResumed(participant: Participant) {
    Log.d(TAG, "${participant.name} resumed their video")
    // Show video stream
}

Java

@Override
public void onParticipantVideoResumed(Participant participant) {
    Log.d(TAG, participant.getName() + " resumed their video");
    // Show video stream
}

---

onParticipantHandRaised

Triggered when a participant raises their hand.

Kotlin

override fun onParticipantHandRaised(participant: Participant) {
    Log.d(TAG, "${participant.name} raised their hand")
    // Show hand raised indicator
    // Optionally play notification sound
}

Java

@Override
public void onParticipantHandRaised(Participant participant) {
    Log.d(TAG, participant.getName() + " raised their hand");
    // Show hand raised indicator
    // Optionally play notification sound
}

---

onParticipantHandLowered

Triggered when a participant lowers their hand.

Kotlin

override fun onParticipantHandLowered(participant: Participant) {
    Log.d(TAG, "${participant.name} lowered their hand")
    // Hide hand raised indicator
}

Java

@Override
public void onParticipantHandLowered(Participant participant) {
    Log.d(TAG, participant.getName() + " lowered their hand");
    // Hide hand raised indicator
}

---

onParticipantStartedScreenShare

Triggered when a participant starts sharing their screen.

Kotlin

override fun onParticipantStartedScreenShare(participant: Participant) {
    Log.d(TAG, "${participant.name} started screen sharing")
    // Switch to screen share view
    // Show screen share indicator
}

Java

@Override
public void onParticipantStartedScreenShare(Participant participant) {
    Log.d(TAG, participant.getName() + " started screen sharing");
    // Switch to screen share view
    // Show screen share indicator
}

---

onParticipantStoppedScreenShare

Triggered when a participant stops sharing their screen.

Kotlin

override fun onParticipantStoppedScreenShare(participant: Participant) {
    Log.d(TAG, "${participant.name} stopped screen sharing")
    // Switch back to normal view
    // Hide screen share indicator
}

Java

@Override
public void onParticipantStoppedScreenShare(Participant participant) {
    Log.d(TAG, participant.getName() + " stopped screen sharing");
    // Switch back to normal view
    // Hide screen share indicator
}

---

onParticipantStartedRecording

Triggered when a participant starts recording the session.

Kotlin

override fun onParticipantStartedRecording(participant: Participant) {
    Log.d(TAG, "${participant.name} started recording")
    // Show recording indicator
    // Notify other participants
}

Java

@Override
public void onParticipantStartedRecording(Participant participant) {
    Log.d(TAG, participant.getName() + " started recording");
    // Show recording indicator
    // Notify other participants
}

---

onParticipantStoppedRecording

Triggered when a participant stops recording the session.

Kotlin

override fun onParticipantStoppedRecording(participant: Participant) {
    Log.d(TAG, "${participant.name} stopped recording")
    // Hide recording indicator
}

Java

@Override
public void onParticipantStoppedRecording(Participant participant) {
    Log.d(TAG, participant.getName() + " stopped recording");
    // Hide recording indicator
}

---

onDominantSpeakerChanged

Triggered when the dominant speaker changes (the participant currently speaking the loudest).

Kotlin

override fun onDominantSpeakerChanged(participant: Participant) {
    Log.d(TAG, "${participant.name} is now the dominant speaker")
    // Highlight the dominant speaker's tile
    // Auto-focus on dominant speaker in spotlight mode
}

Java

@Override
public void onDominantSpeakerChanged(Participant participant) {
    Log.d(TAG, participant.getName() + " is now the dominant speaker");
    // Highlight the dominant speaker's tile
    // Auto-focus on dominant speaker in spotlight mode
}

Use Cases:

• Highlight active speaker in UI
• Auto-switch spotlight to dominant speaker
• Show speaking indicator animation

---

Complete Example

Here’s a complete example handling all participant events:

Kotlin

class CallActivity : AppCompatActivity() {
    private lateinit var callSession: CallSession

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

        callSession = CallSession.getInstance()
        setupParticipantEventListener()
    }

    private fun setupParticipantEventListener() {
        callSession.addParticipantEventListener(this, object : ParticipantEventListener() {
            override fun onParticipantJoined(participant: Participant) {
                runOnUiThread {
                    showToast("${participant.name} joined")
                }
            }

            override fun onParticipantLeft(participant: Participant) {
                runOnUiThread {
                    showToast("${participant.name} left")
                }
            }

            override fun onParticipantListChanged(participants: List<Participant>) {
                runOnUiThread {
                    updateParticipantCount(participants.size)
                }
            }

            override fun onParticipantAudioMuted(participant: Participant) {
                runOnUiThread {
                    updateParticipantAudioState(participant.uid, isMuted = true)
                }
            }

            override fun onParticipantAudioUnmuted(participant: Participant) {
                runOnUiThread {
                    updateParticipantAudioState(participant.uid, isMuted = false)
                }
            }

            override fun onParticipantVideoPaused(participant: Participant) {
                runOnUiThread {
                    updateParticipantVideoState(participant.uid, isPaused = true)
                }
            }

            override fun onParticipantVideoResumed(participant: Participant) {
                runOnUiThread {
                    updateParticipantVideoState(participant.uid, isPaused = false)
                }
            }

            override fun onParticipantHandRaised(participant: Participant) {
                runOnUiThread {
                    showHandRaisedIndicator(participant.uid, isRaised = true)
                }
            }

            override fun onParticipantHandLowered(participant: Participant) {
                runOnUiThread {
                    showHandRaisedIndicator(participant.uid, isRaised = false)
                }
            }

            override fun onParticipantStartedScreenShare(participant: Participant) {
                runOnUiThread {
                    showScreenShareView(participant)
                }
            }

            override fun onParticipantStoppedScreenShare(participant: Participant) {
                runOnUiThread {
                    hideScreenShareView()
                }
            }

            override fun onParticipantStartedRecording(participant: Participant) {
                runOnUiThread {
                    showRecordingIndicator(true)
                }
            }

            override fun onParticipantStoppedRecording(participant: Participant) {
                runOnUiThread {
                    showRecordingIndicator(false)
                }
            }

            override fun onDominantSpeakerChanged(participant: Participant) {
                runOnUiThread {
                    highlightDominantSpeaker(participant.uid)
                }
            }
        })
    }

    // UI helper methods
    private fun showToast(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show()
    }

    private fun updateParticipantCount(count: Int) { /* ... */ }
    private fun updateParticipantAudioState(uid: String, isMuted: Boolean) { /* ... */ }
    private fun updateParticipantVideoState(uid: String, isPaused: Boolean) { /* ... */ }
    private fun showHandRaisedIndicator(uid: String, isRaised: Boolean) { /* ... */ }
    private fun showScreenShareView(participant: Participant) { /* ... */ }
    private fun hideScreenShareView() { /* ... */ }
    private fun showRecordingIndicator(show: Boolean) { /* ... */ }
    private fun highlightDominantSpeaker(uid: String) { /* ... */ }

    companion object {
        private const val TAG = "CallActivity"
    }
}

Java

public class CallActivity extends AppCompatActivity {
    private static final String TAG = "CallActivity";
    private CallSession callSession;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_call);

        callSession = CallSession.getInstance();
        setupParticipantEventListener();
    }

    private void setupParticipantEventListener() {
        callSession.addParticipantEventListener(this, new ParticipantEventListener() {
            @Override
            public void onParticipantJoined(Participant participant) {
                runOnUiThread(() -> showToast(participant.getName() + " joined"));
            }

            @Override
            public void onParticipantLeft(Participant participant) {
                runOnUiThread(() -> showToast(participant.getName() + " left"));
            }

            @Override
            public void onParticipantListChanged(List<Participant> participants) {
                runOnUiThread(() -> updateParticipantCount(participants.size()));
            }

            @Override
            public void onParticipantAudioMuted(Participant participant) {
                runOnUiThread(() -> 
                    updateParticipantAudioState(participant.getUid(), true));
            }

            @Override
            public void onParticipantAudioUnmuted(Participant participant) {
                runOnUiThread(() -> 
                    updateParticipantAudioState(participant.getUid(), false));
            }

            @Override
            public void onParticipantVideoPaused(Participant participant) {
                runOnUiThread(() -> 
                    updateParticipantVideoState(participant.getUid(), true));
            }

            @Override
            public void onParticipantVideoResumed(Participant participant) {
                runOnUiThread(() -> 
                    updateParticipantVideoState(participant.getUid(), false));
            }

            @Override
            public void onParticipantHandRaised(Participant participant) {
                runOnUiThread(() -> 
                    showHandRaisedIndicator(participant.getUid(), true));
            }

            @Override
            public void onParticipantHandLowered(Participant participant) {
                runOnUiThread(() -> 
                    showHandRaisedIndicator(participant.getUid(), false));
            }

            @Override
            public void onParticipantStartedScreenShare(Participant participant) {
                runOnUiThread(() -> showScreenShareView(participant));
            }

            @Override
            public void onParticipantStoppedScreenShare(Participant participant) {
                runOnUiThread(() -> hideScreenShareView());
            }

            @Override
            public void onParticipantStartedRecording(Participant participant) {
                runOnUiThread(() -> showRecordingIndicator(true));
            }

            @Override
            public void onParticipantStoppedRecording(Participant participant) {
                runOnUiThread(() -> showRecordingIndicator(false));
            }

            @Override
            public void onDominantSpeakerChanged(Participant participant) {
                runOnUiThread(() -> highlightDominantSpeaker(participant.getUid()));
            }
        });
    }

    // UI helper methods
    private void showToast(String message) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
    }

    private void updateParticipantCount(int count) { /* ... */ }
    private void updateParticipantAudioState(String uid, boolean isMuted) { /* ... */ }
    private void updateParticipantVideoState(String uid, boolean isPaused) { /* ... */ }
    private void showHandRaisedIndicator(String uid, boolean isRaised) { /* ... */ }
    private void showScreenShareView(Participant participant) { /* ... */ }
    private void hideScreenShareView() { /* ... */ }
    private void showRecordingIndicator(boolean show) { /* ... */ }
    private void highlightDominantSpeaker(String uid) { /* ... */ }
}

---

Callbacks Summary

Callback	Parameter	Description
onParticipantJoined	Participant	A participant joined the call
onParticipantLeft	Participant	A participant left the call
onParticipantListChanged	List<Participant>	Participant list was updated
onParticipantAudioMuted	Participant	A participant muted their audio
onParticipantAudioUnmuted	Participant	A participant unmuted their audio
onParticipantVideoPaused	Participant	A participant paused their video
onParticipantVideoResumed	Participant	A participant resumed their video
onParticipantHandRaised	Participant	A participant raised their hand
onParticipantHandLowered	Participant	A participant lowered their hand
onParticipantStartedScreenShare	Participant	A participant started screen sharing
onParticipantStoppedScreenShare	Participant	A participant stopped screen sharing
onParticipantStartedRecording	Participant	A participant started recording
onParticipantStoppedRecording	Participant	A participant stopped recording
onDominantSpeakerChanged	Participant	The dominant speaker changed

Next Steps

Media Events Listener

Handle local media state changes

Participant Actions

Control other participants