Screen Share - Android

Screen sharing in a meeting is the process of sharing your mobile 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.

How Screen share works?

• The following diagram shows flow of the screen sharing in android using VideoSDK :

enableScreenShare()

• By using enableScreenShare() function of Meeting class, local participant can share his/her mobile screen to other participants.

• You can pass customised screenshare track in enableScreenShare() by using Custom Screen Share Track.

• Screen Share stream of the participant can be accessed from the onStreamEnabled event of ParticipantEventListener.

Screenshare permission

• A participant’s Screen share stream is provided via the MediaProjection API. This API is only compatible with Build.VERSION_CODES.LOLLIPOP or higher.

• Get an instance of the MediaProjectionManager and Call the createScreenCaptureIntent() method in an activity. This initiates a prompt dialog for the user to confirm screen projection.

• One will get a prompt dialog like this:

• After permission is received from the user, you can call enableScreenShare() method.

Kotlin

private fun enableScreenShare() {
    val mediaProjectionManager = application.getSystemService(
        MEDIA_PROJECTION_SERVICE
    ) as MediaProjectionManager
    startActivityForResult(
        mediaProjectionManager.createScreenCaptureIntent(), CAPTURE_PERMISSION_REQUEST_CODE
    )
}

public override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode != CAPTURE_PERMISSION_REQUEST_CODE) return
    if (resultCode == RESULT_OK) {
        // Enabling screen share
        meeting!!.enableScreenShare(data)
    }
}

Java

private void enableScreenShare() {
    MediaProjectionManager mediaProjectionManager =
        (MediaProjectionManager) getApplication().getSystemService(
            Context.MEDIA_PROJECTION_SERVICE);
    startActivityForResult(
        mediaProjectionManager.createScreenCaptureIntent(), CAPTURE_PERMISSION_REQUEST_CODE);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode != CAPTURE_PERMISSION_REQUEST_CODE)
        return;
    if (resultCode == Activity.RESULT_OK) {
        // Enabling screen share
        meeting.enableScreenShare(data);
    }
}

Customise notification

• When a presenter starts screen share, presenter will receive a notification with a pre-defined title and message.

• Notification with pre-defined title and message will look like this:

• You can Customise those title, message and icon as per your requirements using <meta-data> specified in app/src/main/AndroidManifest.xml.

<application>
  <meta-data
    android:name="notificationTitle"
    android:value="@string/notificationTitle"
  />
  <meta-data
    android:name="notificationContent"
    android:value="@string/notificationContent"
  />
  <meta-data
    android:name="notificationIcon"
    android:resource="@mipmap/ic_launcher_round"
  />
</application>

disableScreenShare()

• By using disableScreenShare() function of Meeting class, local participant can stop sharing his/her mobile screen to other participants.

Kotlin

private fun disableScreenShare() {
    // Disabling screen share
    meeting!!.disableScreenShare()
}

Java

private void disableScreenShare(){
    // Disabling screen share
    meeting.disableScreenShare();
}

Events associated with enableScreenShare

• Participant who share their mobile screen will receive a callback on onStreamEnabled() of the Participant with Stream object.

• While other Participants will receive onPresenterChanged() callback of the Meeting class with the participantId as presenterId who started the screen share.

Events associated with disableScreenShare

• Participant who shared their mobile screen will receive a callback on onStreamDisabled() of the Participant with Stream object.

• While other Participants will receive onPresenterChanged() callback of the Meeting class with the presenterId as null indicating there is no presenter.

Kotlin

private fun setLocalListeners() {
    meeting!!.localParticipant.addEventListener(object : ParticipantEventListener() {
        //Callback for when the participant starts a stream
        override fun onStreamEnabled(stream: Stream) {
           if (stream.kind.equals("share", ignoreCase = true)) {
              Log.d("VideoSDK","Share Stream On: onStreamEnabled $stream");
            }
        }

        //Callback for when the participant stops a stream
        override fun onStreamDisabled(stream: Stream) {
            if (stream.kind.equals("share", ignoreCase = true)) {
               Log.d("VideoSDK","Share Stream On: onStreamDisabled $stream");
            }
        }
    });
}

private val meetingEventListener: MeetingEventListener = object : MeetingEventListener() {
    //Callback for when the presenter changes
    override fun onPresenterChanged(participantId: String) {
        if(!TextUtils.isEmpty(participantId))
        {
          Log.d("VideoSDK","$participantId started screen share");
        }else{
          Log.d("VideoSDK","some one stopped screen share");
        }
    }
}

Java

private void setLocalListeners() {
    meeting.getLocalParticipant().addEventListener(new ParticipantEventListener() {
        //Callback for when the participant starts a stream
        @Override
        public void onStreamEnabled(Stream stream) {
            if (stream.getKind().equalsIgnoreCase("share")) {
                Log.d("VideoSDK","Share Stream On: onStreamEnabled" + stream);
            }
        }

        //Callback for when the participant stops a stream
        @Override
        public void onStreamDisabled(Stream stream) {
            if (stream.getKind().equalsIgnoreCase("share")) {
                Log.d("VideoSDK","Share Stream Off: onStreamDisabled" + stream);
            }
        }
    });
}

private final MeetingEventListener meetingEventListener = new MeetingEventListener() {
    //Callback for when the presenter changes
    @Override
    public void onPresenterChanged(String participantId) {
      if(participantId != null){
        Log.d("VideoSDK",participantId + "started screen share");
      }else{
        Log.d("VideoSDK","some one stopped screen share");
      }
    }
};

Rendering Screen Share Stream

• When a local participant shares their screen, the onStreamEnabled() function of the ParticipantEventListener is triggered, allowing the Stream to be added to a VideoView.

Kotlin

private fun setLocalListeners() {
    meeting!!.localParticipant.addEventListener(object : ParticipantEventListener() {
        override fun onStreamEnabled(stream: Stream) {
           if (stream.kind.equals("share", ignoreCase = true)) {
                // display share video
                val videoTrack = stream.track as VideoTrack
                shareView!!.addTrack(videoTrack)
            }
        }
        override fun onStreamDisabled(stream: Stream) {
            if (stream.kind.equals("share", ignoreCase = true)) {
               shareView!!.removeTrack()
            }
        }
    });
}

Java

private void setLocalListeners() {
    meeting.getLocalParticipant().addEventListener(new ParticipantEventListener() {
        @Override
        public void onStreamEnabled(Stream stream) {
            if (stream.getKind().equalsIgnoreCase("share")) {
                // display share video
                VideoTrack videoTrack = (VideoTrack) stream.getTrack();
                shareView.addTrack(videoTrack);
            }
        }
        @Override
        public void onStreamDisabled(Stream stream) {
            if (stream.getKind().equalsIgnoreCase("share")) {
                shareView.removeTrack();
            }
        }
    });
}

• When another participant (excluding the local participant) shares their screen, the onPresenterChanged() function in the MeetingEventListener is triggered, providing the participantId of the screen sharer.

Kotlin

private val meetingEventListener: MeetingEventListener = object : MeetingEventListener() {
    override fun onPresenterChanged(participantId: String) {
        updatePresenter(participantId)
    }
}

//Getting the stream from the participantId
private fun updatePresenter(participantId: String?) {
    // find participant
    val participant = meeting!!.participants.get(participantId) ?: return

    // find share stream in participant
    var shareStream: Stream? = null
    for (stream: Stream in participant.streams.values) {
        if ((stream.kind == "share")) {
            shareStream = stream
            break
        }
    }
    if (shareStream == null) return

    // display share video
    val videoTrack = shareStream.track as VideoTrack
    shareView!!.addTrack(videoTrack)

    // listen for share stop event
    participant.addEventListener(object : ParticipantEventListener() {
        override fun onStreamDisabled(stream: Stream) {
            if ((stream.kind == "share")) {
                shareView!!.removeTrack()
            }
        }
    })
}

Java

private final MeetingEventListener meetingEventListener = new MeetingEventListener() {
    //Triggered when Presenter changes
    @Override
    public void onPresenterChanged(String participantId) {
        updatePresenter(participantId);
    }
};

//Getting the stream from the participantId
private void updatePresenter(String participantId) {
    // find participant
    Participant participant = meeting.getParticipants().get(participantId);
    if (participant == null) return;

    // find share stream in participant
    Stream shareStream = null;
    for (Stream stream: participant.getStreams().values()) {
        if (stream.getKind().equals("share")) {
            shareStream = stream;
            break;
        }
    }
    if (shareStream == null) return;

    // display share video
    VideoTrack videoTrack = (VideoTrack) shareStream.getTrack();
    shareView.addTrack(videoTrack)

    // listen for share stop event
    participant.addEventListener(new ParticipantEventListener() {
        @Override
        public void onStreamDisabled(Stream stream) {
            if (stream.getKind().equals("share")) {
                shareView.removeTrack();
            }
        }
    });
}

info

• Here screenShare stream is displayed using VideoView, but you may also use SurfaceViewRender for the same.
• For VideoView, SDK version should be 0.1.13 or higher.
• To know more about VideoView, please visit here

API Reference

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

• enableScreenShare()
• disableScreenShare()
• onStreamEnabled()
• onStreamDisabled()
• onPresenterChanged()