Media Events - Flutter

VideoSDK offers various events that can be monitored to obtain information about the media status of participants in the room.

Here are the events specifically related to the stream:

Events.streamEnabled

• This event is triggered whenever a participant's video, audio or screen share stream is enabled, including your own.
• It can be subscribed to using the Room object.
• The handler receives the RTCStream. stream.participantId is the id of the participant the stream belongs to, and stream.kind is a MediaType.

Events.streamDisabled

• This event is triggered whenever a participant's video, audio or screen share stream is disabled, including your own.
• It can be subscribed to using the Room object.
• The handler receives the RTCStream. stream.participantId is the id of the participant the stream belongs to, and stream.kind is a MediaType.

Events.streamPaused

• This event is triggered whenever a video, audio or screen share stream you receive is paused.
• It can be subscribed to using the Room object.
• The handler receives the stream's kind (audio, video or share) and the reason, both as String?. The room's handler does not say which participant's stream was paused; a handler added with participant.on() gets only that participant's streams.

Events.streamResumed

• This event is triggered whenever a paused stream you receive is resumed.
• It can be subscribed to using the Room object.
• The handler receives the stream's kind and the reason, both as String?. The room's handler does not say which participant's stream was resumed; a handler added with participant.on() gets only that participant's streams.

note

Each of these events is also delivered on the participant who owns the stream. Listen with participant.on() in a participant tile.

Example

Here is an example demonstrating the usage of all the events mentioned on this page.

A participant tile listens for its participant's streams on the room. Streams that already exist when the tile is built are in participant.streams.

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';

class ParticipantTile extends StatefulWidget {
  final Room room;
  final Participant participant;
  //Existing configuration
}

class _ParticipantTileState extends State<ParticipantTile> {
  @override
  void initState() {
    super.initState();
    //Existing configuration

    setupRoomEventListener();
  }

  @override
  Widget build(BuildContext context) {
    return YourParticipantTileWidget();
  }

  void setupRoomEventListener() {
    widget.room.on(Events.streamEnabled, _onStreamEnabled);
    widget.room.on(Events.streamDisabled, _onStreamDisabled);
  }

  void _onStreamEnabled(RTCStream stream) {
    // The room reports every participant's streams, so keep only this one's
    if (stream.participantId != widget.participant.id) return;

    if (stream.kind == MediaType.VIDEO) {
      // Participant turned on video
    } else if (stream.kind == MediaType.AUDIO) {
      // Participant turned on audio
    } else if (stream.kind == MediaType.SHARE) {
      // Participant started screenshare
    }
  }

  void _onStreamDisabled(RTCStream stream) {
    if (stream.participantId != widget.participant.id) return;

    if (stream.kind == MediaType.VIDEO) {
      // Participant turned off video
    } else if (stream.kind == MediaType.AUDIO) {
      // Participant turned off audio
    } else if (stream.kind == MediaType.SHARE) {
      // Participant stopped screenshare
    }
  }

  @override
  void dispose() {
    // The room outlives the tile, so remove the handlers from it
    widget.room.off(Events.streamEnabled, _onStreamEnabled);
    widget.room.off(Events.streamDisabled, _onStreamDisabled);
    super.dispose();
  }
}

On the room, streamPaused and streamResumed do not say whose stream it was. Listen for them on the room to react to any pause, or with participant.on() in a tile.

import 'package:flutter/material.dart';
import 'package:videosdk/videosdk.dart';

class RoomScreen extends StatefulWidget {
  //Existing configuration
}

class _RoomScreenState extends State<RoomScreen> {
  late Room room;

  @override
  void initState() {
    super.initState();
    //Existing configuration

    setupRoomEventListener();
  }

  @override
  Widget build(BuildContext context) {
    return YourRoomWidget();
  }

  void setupRoomEventListener() {
    room.on(Events.streamPaused, (String? kind, String? reason) {
      if (kind == "video") {
        // A video stream you receive was paused
      } else if (kind == "audio") {
        // An audio stream you receive was paused
      } else if (kind == "share") {
        // A screenshare stream you receive was paused
      }
    });

    room.on(Events.streamResumed, (String? kind, String? reason) {
      if (kind == "video") {
        // A video stream you receive was resumed
      } else if (kind == "audio") {
        // An audio stream you receive was resumed
      } else if (kind == "share") {
        // A screenshare stream you receive was resumed
      }
    });
  }
}

Stream state

Each RTCStream also reports whether it is active, stuck or frozen. Listen with stream.on(Events.streamStateChanged, (StreamState state, int timestamp) {}). See Stream Events.

API Reference

The API references for all the methods and events utilized in this guide are provided below.

• Events.streamEnabled
• Events.streamDisabled
• Events.streamPaused
• Events.streamResumed
• room.off()