Screen Share - Flutter

Screen sharing in a meeting is the process of sharing your device screen with other participants in the meeting. It allows everyone in the meeting to see exactly what you are seeing on your screen, which can be helpful for presentations, demonstrations, or collaborations.

Screen Share feature Compatibility

Android and iOS app	Web	Desktop app	Safari browser
✅	✅	✅	❌

enableScreenShare()

• By using enableScreenShare() function of Room object, local participant can share his/her screen or window to other participants.

• Screen Share stream of the participant can be accessed from the streams property of Participant object.

disableScreenShare()

• By using disableScreenShare() function of Room object, local participant can stop sharing his/her screen or window to other participants.

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

class MeetingScreen extends StatefulWidget {
  ...
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room _room;

  @override
  void initState() {
    ...
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children:[
        ElevatedButton(
          onPressed:(){
            _room.enableScreenShare();
          },
          child: const Text("Enable Screen Share"),
        ),
        ElevatedButton(
          onPressed:(){
            _room.disableScreenShare();
          },
          child: const Text("Disable Screen Share"),
        ),
      ]
    );
  }
}

iOS Setup

note

For Flutter iOS Screen Share feature, you need to follow this guide Flutter iOS Screen Share

Rendering Screen Share Stream

1. To render the screenshare, you will need the participantId who is presenting the screen, which can be found from the presenterId property of Room object.

We will listen for the Events.presenterChanged on Room object to check if some other participant starts screen share, Events.streamEnabled and Events.streamDisabled on the localParticipant's object to identify if the local participant is presenting or not.

meeting_screen.dart

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

class MeetingScreen extends StatefulWidget {
  final String meetingId;
  final String token;

  const MeetingScreen(
      {super.key, required this.meetingId, required this.token});

  @override
  State<MeetingScreen> createState() => _MeetingScreenState();
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room _room;
  String? _presenterId;


  @override
  void initState() {
    // create room
    _room = VideoSDK.createRoom(
      roomId: widget.meetingId,
      token: widget.token,
      displayName: "John Doe",
      micEnabled: true,
      camEnabled: true,
      defaultCameraIndex:
          1, // Index of MediaDevices will be used to set default camera
    );

    setMeetingEventListener();

    // Join room
    _room.join();

    super.initState();
  }

  // listening to meeting events
  void setMeetingEventListener() {
    _room.on(Events.roomLeft, () {
      participants.clear();
      Navigator.popUntil(context, ModalRoute.withName('/'));
    });
    //Listening if remote participant starts presenting
    _room.on(Events.presenterChanged, (String? presenterId) {
      setState(() => {_presenterId = presenterId});
    });

    //Listening if local participant starts presenting
    _room.localParticipant.on(Events.streamEnabled, (Stream stream) {
      if (stream.kind == "share") {
        setState(() => {_presenterId = _room.localParticipant.id});
      }
    });

    _room.localParticipant.on(Events.streamDisabled, (Stream stream) {
      if (stream.kind == "share") {
        setState(() => {_presenterId = null});
      }
    });
  }

  // onbackButton pressed leave the room
  Future<bool> _onWillPop() async {
    _room.leave();
    return true;
  }

  @override
  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: () => _onWillPop(),
      child: Scaffold(
        appBar: AppBar(
          title: const Text('VideoSDK QuickStart'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            children: [
              Text(widget.meetingId),
              //we will render the screenshare view if the presenterId is not null
              if (_presenterId != null)
                ScreenShareView(
                  participant: _presenterId == _room.localParticipant.id
                      ? _room.localParticipant
                      : _room.participants[_presenterId],
                ),
              ElevatedButton(
                  onPressed: () {
                    if (_presenterId != null) {
                      _room.disableScreenShare();
                    } else {
                      _room.enableScreenShare();
                    }
                  },
                  child: const Text('Toggle Screnshare')),
            ],
          ),
        ),
      ),
    );
  }
}

2. Now that we know if there is an active presenter, let us get the screen share stream from the Participant object and render it.

screen_share_view.dart

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

class ScreenShareView extends StatelessWidget {
  final Participant? participant;

  ScreenShareView({super.key, required this.participant}) {
  //intialize the shareStream
    participant?.streams.forEach((key, value) {
      if (value.kind == "share") {
        shareStream = value;
      }
    });
  }
  Stream? shareStream;

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.grey.shade800,
      height: 300,
      width: 200,
      //show the screen share stream
      child: shareStream != null
          ? RTCVideoView(
              shareStream?.renderer as RTCVideoRenderer,
              objectFit: RTCVideoViewObjectFit.RTCVideoViewObjectFitCover,
            )
          : null,
    );
  }
}

Events associated with enableScreenShare

• Every Participant will receive a callback on Events.streamEnabled of the Participant object with Stream object.

• Every Remote Participant will receive Events.presenterChanged callback on the Room object with the participantId as presenterId who started the screen share.

Events associated with disableScreenShare

• Every Participant will receive a callback on Events.streamDisabled of the Participant object with Stream object.

• Every Remote Participant will receive Events.presenterChanged callback on the Room object with the presenterId as null.

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

class ParticipantTile extends StatefulWidget {
  final Participant participant;
  ...
}

class _ParticipantTileState extends State<ParticipantTile> {

  @override
  void initState() {
    ...

    _initStreamListeners();
    super.initState();
  }

  //Change state according to the events received
  _initStreamListeners() {
    widget.participant.on(Events.streamEnabled, (Stream stream) {
      if (stream.kind == 'share') {
        //Screen share Turned On
      }
    });

    widget.participant.on(Events.streamDisabled, (Stream stream) {
      if (stream.kind == 'share') {
        //Screen Share Turned Off
      }
    });
  }

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

class MeetingScreen extends StatefulWidget {
  ...
}

class _MeetingScreenState extends State<MeetingScreen> {
  late Room room;

  @override
  void initState() {
    ...

    setupRoomEventListener();
  }

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

  void setupRoomEventListener() {

    room.on(Events.presenterChanged, (String? presenterId) {
      //Room screen presenter has changed
      //Participant ID of current presenter is presenterId
    });
  }
}

API Reference

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

• enableScreenShare()
• disableScreenShare()
• Events.streamEnabled
• Events.streamDisabled