bigbluebutton-Github/bigbluebutton-html5/imports/ui/components/screenshare/service.js

import Screenshare from '/imports/api/screenshare';
import KurentoBridge from '/imports/api/screenshare/client/bridge';
import Settings from '/imports/ui/services/settings';
import logger from '/imports/startup/client/logger';
import { tryGenerateIceCandidates } from '/imports/utils/safari-webrtc';
import { stopWatching } from '/imports/ui/components/external-video-player/service';
import Meetings from '/imports/api/meetings';
import Auth from '/imports/ui/services/auth';

// when the meeting information has been updated check to see if it was
// screensharing. If it has changed either trigger a call to receive video
// and display it, or end the call and hide the video
const isVideoBroadcasting = () => {
  const ds = Screenshare.findOne({});

  if (!ds) {
    return false;
  }

  return !!ds.screenshare.stream;
};

// if remote screenshare has been ended disconnect and hide the video stream
const presenterScreenshareHasEnded = () => {
  // references a function in the global namespace inside kurento-extension.js
  // that we load dynamically
  KurentoBridge.kurentoExitVideo();
};

// if remote screenshare has been started connect and display the video stream
const presenterScreenshareHasStarted = () => {
  // KurentoBridge.kurentoWatchVideo: references a function in the global
  // namespace inside kurento-extension.js that we load dynamically

  // WebRTC restrictions may need a capture device permission to release
  // useful ICE candidates on recvonly/no-gUM peers
  tryGenerateIceCandidates().then(() => {
    KurentoBridge.kurentoWatchVideo();
  }).catch((error) => {
    logger.error({
      logCode: 'screenshare_no_valid_candidate_gum_failure',
      extraInfo: {
        errorName: error.name,
        errorMessage: error.message,
      },
    }, `Forced gUM to release additional ICE candidates failed due to ${error.name}.`);
    // The fallback gUM failed. Try it anyways and hope for the best.
    KurentoBridge.kurentoWatchVideo();
  });
};

const shareScreen = (onFail) => {
  // stop external video share if running
  const meeting = Meetings.findOne({ meetingId: Auth.meetingID });
  if (meeting && meeting.externalVideoUrl) {
    stopWatching();
  }

  KurentoBridge.kurentoShareScreen(onFail);
};

const screenShareEndAlert = () => new Audio(`${Meteor.settings.public.app.cdn + Meteor.settings.public.app.basename}/resources/sounds/ScreenshareOff.mp3`).play();

const unshareScreen = () => {
  KurentoBridge.kurentoExitScreenShare();
  screenShareEndAlert();
};

const dataSavingSetting = () => Settings.dataSaving.viewScreenshare;

export {
  isVideoBroadcasting,
  presenterScreenshareHasEnded,
  presenterScreenshareHasStarted,
  shareScreen,
  screenShareEndAlert,
  unshareScreen,
  dataSavingSetting,
};