Call & Participant State

Video Call State

When you join a call, we'll automatically expose 3 StateFlow objects:

val clientState = streamVideo.state
val callState = call.state
val participants = call.state.participants

Call State

Here's an example of how you can access the call state:

val call = client.call("default", "mycall")
val joinResult = call.join(create=true)
// state is now available at
val state = call.state

The following fields are available on the call

Participant State

The ParticipantsState is the most essential component used to render a participant in a call. It contains all of the information to render a participant, such as audio & video renderers, availabilities of audio & video, the screen sharing session, reactions, and etc. Here's how you iterate over the participants:

// all participants
val participants: StateFlow<List<ParticipantState>> = call.state.participants
coroutineScope.launch {
    participants.collectLatest { participants ->
        // ..
    }
}

// all participants in Jetpack Compose
val participants: List<ParticipantState> by call.state.participants.collectAsState()
participants.forEach { participantState ->
    // ..
}

// you
val me: StateFlow<ParticipantState?> = call.state.me

In Jetpack Compose, you can observe the ParticipantsState and render videos like the example below:

// all participants
val participants by call.state.participants.collectAsState()

LazyColumn {
    items(items = participants, key = { it.sessionId }) { participant ->
        ParticipantVideo(call = call, participant = participant)
    }
}

// you
val me by call.state.me.collectAsState()

ParticipantVideo(
    call = call,
    participant = me
)

The following fields are available on the participant

Participants Sorting

call.state.participants is always sorted by the active sort preset. The preset is picked up automatically from the call type (e.g. livestream calls use LivestreamOrAudioRoom; other types use Default). You can switch the preset at any time, or pass a custom comparator.

Available presets

Switching the preset

call.state.setSortPreset(SortPreset.SpeakerLayout)

Custom comparator

For ad-hoc orderings that don't fit a preset, use updateParticipantSortingOrder. The example below sorts participants alphabetically by name:

call.state.updateParticipantSortingOrder(
    compareByDescending {
        it.name.value
    },
)

Calling setSortPreset(...) again clears any custom comparator.

Composing your own preset

If you want to build a custom comparator from the same primitives the built-in presets use, the io.getstream.video.android.core.sorting package exposes them: dominantSpeaker, speaking, screenSharing, publishingVideo, publishingAudio, raisedHand, byUserId, byRole(vararg), bySourcePriority(vararg ParticipantSource), plus the combinators combineComparators, conditional, ifInvisible, and ifInvisibleOrUnknown. The surface mirrors the iOS and React SDKs.

Detecting participant source

Participants can be created from different sources (WebRTC, RTMP/OBS, WHIP, SIP, etc...). The source property of the ParticipantState object indicates the source of the participant.

val participants = call.state.participants.value
// participants joining through OBS have RTMP source
val rtmpParticipants = participants.filter {
    it.source == ParticipantSource.PARTICIPANT_SOURCE_RTMP
}

Client State

// client state is available on the client object
val state = client.state

And contains these fields: