chrome screen share - page js

opentok_screenshare.js

/*
 * Check if user has extension installed and launch
 *
 */
function shareScreen() {

  // Chrome screen-sharing extension ID
  var extensionId = 'dgckdhnehiggafbppghjpnapieoegekl';

  // check that the extension is installed by looking for a 
  // sessionStorage variable that contains the extension id
  // this has to be set after installation unless the content
  // script does that
  //if (sessionStorage.getScreenMediaJSExtensionId) {
      // sends a message to the chrome extension (background.js)
      chrome.runtime.sendMessage(
        extensionId,
        { type:'getScreen', id: 1 },
        function(response) {
          if (response) {
            if (response.sourceId === '') {
              // user canceled
            } else {
              launchScreenShare(extensionId);
            }
          } else {
            installChromeExtension();
          }
          launchScreenShare(extensionId);
      }); // disconnect is called here
   } else {
     installChromeExtension();
   }
}

/*
 * Prompt user to install extension
 *
 */
function installChromeExtension() {
  // set modal pop-up text
  var installHtml  = 'You need to install the Chrome extension in order to share your screen.';
      installHtml += '<ol>';
      installHtml += '  <li>Click <b>Install Screenshare Extension</b></li>';
      installHtml += '  <li>Click <b>Add Extension</b> in the pop-up</li>';
      installHtml += '</ol>';

  $('#sfModal').find('h4').html('Chrome extension required'); 
  $('#sfModal').find('p').html(installHtml); 
  $('#sfModal').modal('show');
}


function launchScreenShare(extensionId) {
    // opentok settings
    var apiKey    = API.key,
        sessionId = API.session,
        token     = API.token;

    // For Google Chrome only, register your extension by ID,
    // You can find it at chrome://extensions once the extension is installed
    OT.registerScreenSharingExtension('chrome', extensionId);

    // Check that user has a supported browser and plugin installed
    // if so, go ahead and publish
    OT.checkScreenSharingCapability(function(response) {
      if (!response.supported) {
        alert('This browser does not support screen sharing.  Please use the Google Chrome browser.');
      } else {
   
        var pubOptions = {
          videoSource : 'screen',
          insertMode: 'append',
          width: '100%',
          height: '100%',
        }

        // Screen sharing is available, now publish it! 
        var screenSharingPublisher = OT.initPublisher(
          'videoContainer',
          pubOptions,
          function(error) {
            if (error) {
              console.log("Screen sharing cancelled by user.");
            } else {
              session.publish(
                screenSharingPublisher,
                function(error) {
                  if (error) {
                    alert('Sorry, there was a problem with screensharing. Please try again or contact SpeedFaces support. ' + error.message);
                  } 
                });
            }
        });

        // user stopped sharing screen event
        screenSharingPublisher.on("streamDestroyed", function () {
           console.log("destroyed!");
        });

      }
    });
}

/*  background-script.js */
/* background page, responsible for actually choosing media */
chrome.runtime.onMessageExternal.addListener(function (message, sender, callback) {
    switch(message.type) {
        case 'getScreen':
            var pending = chrome.desktopCapture.chooseDesktopMedia(message.options || ['screen', 'window'],
                                                                   sender.tab, function (streamid) {
                // communicate this string to the app so it can call getUserMedia with it
                message.type = 'gotScreen';
                message.sourceId = streamid;
                callback(message);
                return false;
            });
            return true; // retain callback for chooseDesktopMedia result
        case 'cancelGetScreen':
            chrome.desktopCapture.cancelChooseDesktopMedia(message.request);
            message.type = 'canceledGetScreen';
            callback(message);
            return false; //dispose callback
    }
});

/* content-script.js */
sessionStorage.getScreenMediaJSExtensionId = chrome.runtime.id;

123123