lib-jitsi-meet/modules/RTC/adapter.screenshare.js

/*! adapterjs - v0.12.3 - 2015-11-16 */
var console = require("jitsi-meet-logger").getLogger(__filename);
// Adapter's interface.
var AdapterJS = AdapterJS || {};

// Browserify compatibility
if(typeof exports !== 'undefined') {
  module.exports = AdapterJS;
}

AdapterJS.options = AdapterJS.options || {};

// uncomment to get virtual webcams
// AdapterJS.options.getAllCams = true;

// uncomment to prevent the install prompt when the plugin in not yet installed
// AdapterJS.options.hidePluginInstallPrompt = true;

// AdapterJS version
AdapterJS.VERSION = '0.12.3';

// This function will be called when the WebRTC API is ready to be used
// Whether it is the native implementation (Chrome, Firefox, Opera) or
// the plugin
// You may Override this function to synchronise the start of your application
// with the WebRTC API being ready.
// If you decide not to override use this synchronisation, it may result in
// an extensive CPU usage on the plugin start (once per tab loaded)
// Params:
//    - isUsingPlugin: true is the WebRTC plugin is being used, false otherwise
//
AdapterJS.onwebrtcready = AdapterJS.onwebrtcready || function(isUsingPlugin) {
  // The WebRTC API is ready.
  // Override me and do whatever you want here
};

// Sets a callback function to be called when the WebRTC interface is ready.
// The first argument is the function to callback.\
// Throws an error if the first argument is not a function
AdapterJS.webRTCReady = function (callback) {
  if (typeof callback !== 'function') {
    throw new Error('Callback provided is not a function');
  }

  if (true === AdapterJS.onwebrtcreadyDone) {
    // All WebRTC interfaces are ready, just call the callback
    callback(null !== AdapterJS.WebRTCPlugin.plugin);
  } else {
    // will be triggered automatically when your browser/plugin is ready.
    AdapterJS.onwebrtcready = callback;
  }
};

// Plugin namespace
AdapterJS.WebRTCPlugin = AdapterJS.WebRTCPlugin || {};

// The object to store plugin information
AdapterJS.WebRTCPlugin.pluginInfo = {
  prefix : 'Tem',
  plugName : 'TemWebRTCPlugin',
  pluginId : 'plugin0',
  type : 'application/x-temwebrtcplugin',
  onload : '__TemWebRTCReady0',
  portalLink : 'http://skylink.io/plugin/',
  downloadLink : null, //set below
  companyName: 'Temasys'
};
if(!!navigator.platform.match(/^Mac/i)) {
  AdapterJS.WebRTCPlugin.pluginInfo.downloadLink = 'http://bit.ly/1n77hco';
}
else if(!!navigator.platform.match(/^Win/i)) {
  AdapterJS.WebRTCPlugin.pluginInfo.downloadLink = 'http://bit.ly/1kkS4FN';
}

AdapterJS.WebRTCPlugin.TAGS = {
  NONE  : 'none',
  AUDIO : 'audio',
  VIDEO : 'video'
};

// Unique identifier of each opened page
AdapterJS.WebRTCPlugin.pageId = Math.random().toString(36).slice(2);

// Use this whenever you want to call the plugin.
AdapterJS.WebRTCPlugin.plugin = null;

// Set log level for the plugin once it is ready.
// The different values are
// This is an asynchronous function that will run when the plugin is ready
AdapterJS.WebRTCPlugin.setLogLevel = null;

// Defines webrtc's JS interface according to the plugin's implementation.
// Define plugin Browsers as WebRTC Interface.
AdapterJS.WebRTCPlugin.defineWebRTCInterface = null;

// This function detects whether or not a plugin is installed.
// Checks if Not IE (firefox, for example), else if it's IE,
// we're running IE and do something. If not it is not supported.
AdapterJS.WebRTCPlugin.isPluginInstalled = null;

 // Lets adapter.js wait until the the document is ready before injecting the plugin
AdapterJS.WebRTCPlugin.pluginInjectionInterval = null;

// Inject the HTML DOM object element into the page.
AdapterJS.WebRTCPlugin.injectPlugin = null;

// States of readiness that the plugin goes through when
// being injected and stated
AdapterJS.WebRTCPlugin.PLUGIN_STATES = {
  NONE : 0,           // no plugin use
  INITIALIZING : 1,   // Detected need for plugin
  INJECTING : 2,      // Injecting plugin
  INJECTED: 3,        // Plugin element injected but not usable yet
  READY: 4            // Plugin ready to be used
};

// Current state of the plugin. You cannot use the plugin before this is
// equal to AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY
AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.NONE;

// True is AdapterJS.onwebrtcready was already called, false otherwise
// Used to make sure AdapterJS.onwebrtcready is only called once
AdapterJS.onwebrtcreadyDone = false;

// Log levels for the plugin.
// To be set by calling AdapterJS.WebRTCPlugin.setLogLevel
/*
Log outputs are prefixed in some cases.
  INFO: Information reported by the plugin.
  ERROR: Errors originating from within the plugin.
  WEBRTC: Error originating from within the libWebRTC library
*/
// From the least verbose to the most verbose
AdapterJS.WebRTCPlugin.PLUGIN_LOG_LEVELS = {
  NONE : 'NONE',
  ERROR : 'ERROR',
  WARNING : 'WARNING',
  INFO: 'INFO',
  VERBOSE: 'VERBOSE',
  SENSITIVE: 'SENSITIVE'
};

// Does a waiting check before proceeding to load the plugin.
AdapterJS.WebRTCPlugin.WaitForPluginReady = null;

// This methid will use an interval to wait for the plugin to be ready.
AdapterJS.WebRTCPlugin.callWhenPluginReady = null;

// !!!! WARNING: DO NOT OVERRIDE THIS FUNCTION. !!!
// This function will be called when plugin is ready. It sends necessary
// details to the plugin.
// The function will wait for the document to be ready and the set the
// plugin state to AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY,
// indicating that it can start being requested.
// This function is not in the IE/Safari condition brackets so that
// TemPluginLoaded function might be called on Chrome/Firefox.
// This function is the only private function that is not encapsulated to
// allow the plugin method to be called.
__TemWebRTCReady0 = function () {
  if (document.readyState === 'complete') {
    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY;

    AdapterJS.maybeThroughWebRTCReady();
  } else {
    AdapterJS.WebRTCPlugin.documentReadyInterval = setInterval(function () {
      if (document.readyState === 'complete') {
        // TODO: update comments, we wait for the document to be ready
        clearInterval(AdapterJS.WebRTCPlugin.documentReadyInterval);
        AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY;

        AdapterJS.maybeThroughWebRTCReady();
      }
    }, 100);
  }
};

AdapterJS.maybeThroughWebRTCReady = function() {
  if (!AdapterJS.onwebrtcreadyDone) {
    AdapterJS.onwebrtcreadyDone = true;

    if (typeof(AdapterJS.onwebrtcready) === 'function') {
      AdapterJS.onwebrtcready(AdapterJS.WebRTCPlugin.plugin !== null);
    }
  }
};

// Text namespace
AdapterJS.TEXT = {
  PLUGIN: {
    REQUIRE_INSTALLATION: 'This website requires you to install a WebRTC-enabling plugin ' +
      'to work on this browser.',
    NOT_SUPPORTED: 'Your browser does not support WebRTC.',
    BUTTON: 'Install Now'
  },
  REFRESH: {
    REQUIRE_REFRESH: 'Please refresh page',
    BUTTON: 'Refresh Page'
  }
};

// The result of ice connection states.
// - starting: Ice connection is starting.
// - checking: Ice connection is checking.
// - connected Ice connection is connected.
// - completed Ice connection is connected.
// - done Ice connection has been completed.
// - disconnected Ice connection has been disconnected.
// - failed Ice connection has failed.
// - closed Ice connection is closed.
AdapterJS._iceConnectionStates = {
  starting : 'starting',
  checking : 'checking',
  connected : 'connected',
  completed : 'connected',
  done : 'completed',
  disconnected : 'disconnected',
  failed : 'failed',
  closed : 'closed'
};

//The IceConnection states that has been fired for each peer.
AdapterJS._iceConnectionFiredStates = [];


// Check if WebRTC Interface is defined.
AdapterJS.isDefined = null;

// This function helps to retrieve the webrtc detected browser information.
// This sets:
// - webrtcDetectedBrowser: The browser agent name.
// - webrtcDetectedVersion: The browser version.
// - webrtcDetectedType: The types of webRTC support.
//   - 'moz': Mozilla implementation of webRTC.
//   - 'webkit': WebKit implementation of webRTC.
//   - 'plugin': Using the plugin implementation.
AdapterJS.parseWebrtcDetectedBrowser = function () {
  var hasMatch, checkMatch = navigator.userAgent.match(
    /(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
  if (/trident/i.test(checkMatch[1])) {
    hasMatch = /\brv[ :]+(\d+)/g.exec(navigator.userAgent) || [];
    webrtcDetectedBrowser = 'IE';
    webrtcDetectedVersion = parseInt(hasMatch[1] || '0', 10);
  } else if (checkMatch[1] === 'Chrome') {
    hasMatch = navigator.userAgent.match(/\bOPR\/(\d+)/);
    if (hasMatch !== null) {
      webrtcDetectedBrowser = 'opera';
      webrtcDetectedVersion = parseInt(hasMatch[1], 10);
    }
  }
  if (navigator.userAgent.indexOf('Safari')) {
    if (typeof InstallTrigger !== 'undefined') {
      webrtcDetectedBrowser = 'firefox';
    } else if (/*@cc_on!@*/ false || !!document.documentMode) {
      webrtcDetectedBrowser = 'IE';
    } else if (
      Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0) {
      webrtcDetectedBrowser = 'safari';
    } else if (!!window.opera || navigator.userAgent.indexOf(' OPR/') >= 0) {
      webrtcDetectedBrowser = 'opera';
    } else if (!!window.chrome) {
      webrtcDetectedBrowser = 'chrome';
    }
  }
  if (!webrtcDetectedBrowser) {
    webrtcDetectedVersion = checkMatch[1];
  }
  if (!webrtcDetectedVersion) {
    try {
      checkMatch = (checkMatch[2]) ? [checkMatch[1], checkMatch[2]] :
        [navigator.appName, navigator.appVersion, '-?'];
      if ((hasMatch = navigator.userAgent.match(/version\/(\d+)/i)) !== null) {
        checkMatch.splice(1, 1, hasMatch[1]);
      }
      webrtcDetectedVersion = parseInt(checkMatch[1], 10);
    } catch (error) { }
  }
};

// To fix configuration as some browsers does not support
// the 'urls' attribute.
AdapterJS.maybeFixConfiguration = function (pcConfig) {
  if (pcConfig === null) {
    return;
  }
  for (var i = 0; i < pcConfig.iceServers.length; i++) {
    if (pcConfig.iceServers[i].hasOwnProperty('urls')) {
      pcConfig.iceServers[i].url = pcConfig.iceServers[i].urls;
      delete pcConfig.iceServers[i].urls;
    }
  }
};

AdapterJS.addEvent = function(elem, evnt, func) {
  if (elem.addEventListener) { // W3C DOM
    elem.addEventListener(evnt, func, false);
  } else if (elem.attachEvent) {// OLD IE DOM
    elem.attachEvent('on'+evnt, func);
  } else { // No much to do
    elem[evnt] = func;
  }
};

AdapterJS.renderNotificationBar = function (text, buttonText, buttonLink, openNewTab, displayRefreshBar) {
  // only inject once the page is ready
  if (document.readyState !== 'complete') {
    return;
  }

  var w = window;
  var i = document.createElement('iframe');
  i.style.position = 'fixed';
  i.style.top = '-41px';
  i.style.left = 0;
  i.style.right = 0;
  i.style.width = '100%';
  i.style.height = '40px';
  i.style.backgroundColor = '#ffffe1';
  i.style.border = 'none';
  i.style.borderBottom = '1px solid #888888';
  i.style.zIndex = '9999999';
  if(typeof i.style.webkitTransition === 'string') {
    i.style.webkitTransition = 'all .5s ease-out';
  } else if(typeof i.style.transition === 'string') {
    i.style.transition = 'all .5s ease-out';
  }
  document.body.appendChild(i);
  c = (i.contentWindow) ? i.contentWindow :
    (i.contentDocument.document) ? i.contentDocument.document : i.contentDocument;
  c.document.open();
  c.document.write('<span style="display: inline-block; font-family: Helvetica, Arial,' +
    'sans-serif; font-size: .9rem; padding: 4px; vertical-align: ' +
    'middle; cursor: default;">' + text + '</span>');
  if(buttonText && buttonLink) {
    c.document.write('<button id="okay">' + buttonText + '</button><button id="cancel">Cancel</button>');
    c.document.close();

    // On click on okay
    AdapterJS.addEvent(c.document.getElementById('okay'), 'click', function(e) {
      if (!!displayRefreshBar) {
        AdapterJS.renderNotificationBar(AdapterJS.TEXT.EXTENSION ?
          AdapterJS.TEXT.EXTENSION.REQUIRE_REFRESH : AdapterJS.TEXT.REFRESH.REQUIRE_REFRESH,
          AdapterJS.TEXT.REFRESH.BUTTON, 'javascript:location.reload()');
      }
      window.open(buttonLink, !!openNewTab ? '_blank' : '_top');

      e.preventDefault();
      try {
        event.cancelBubble = true;
      } catch(error) { }

      var pluginInstallInterval = setInterval(function(){
        if(! isIE) {
          navigator.plugins.refresh(false);
        }
        AdapterJS.WebRTCPlugin.isPluginInstalled(
          AdapterJS.WebRTCPlugin.pluginInfo.prefix,
          AdapterJS.WebRTCPlugin.pluginInfo.plugName,
          function() { // plugin now installed
            clearInterval(pluginInstallInterval);
            AdapterJS.WebRTCPlugin.defineWebRTCInterface();
          },
          function() {
            // still no plugin detected, nothing to do
          });
      } , 500);
    });

    // On click on Cancel
    AdapterJS.addEvent(c.document.getElementById('cancel'), 'click', function(e) {
      w.document.body.removeChild(i);
    });
  } else {
    c.document.close();
  }
  setTimeout(function() {
    if(typeof i.style.webkitTransform === 'string') {
      i.style.webkitTransform = 'translateY(40px)';
    } else if(typeof i.style.transform === 'string') {
      i.style.transform = 'translateY(40px)';
    } else {
      i.style.top = '0px';
    }
  }, 300);
};

// -----------------------------------------------------------
// Detected webrtc implementation. Types are:
// - 'moz': Mozilla implementation of webRTC.
// - 'webkit': WebKit implementation of webRTC.
// - 'plugin': Using the plugin implementation.
webrtcDetectedType = null;

// Detected webrtc datachannel support. Types are:
// - 'SCTP': SCTP datachannel support.
// - 'RTP': RTP datachannel support.
webrtcDetectedDCSupport = null;

// Set the settings for creating DataChannels, MediaStream for
// Cross-browser compability.
// - This is only for SCTP based support browsers.
// the 'urls' attribute.
checkMediaDataChannelSettings =
  function (peerBrowserAgent, peerBrowserVersion, callback, constraints) {
  if (typeof callback !== 'function') {
    return;
  }
  var beOfferer = true;
  var isLocalFirefox = webrtcDetectedBrowser === 'firefox';
  // Nightly version does not require MozDontOfferDataChannel for interop
  var isLocalFirefoxInterop = webrtcDetectedType === 'moz' && webrtcDetectedVersion > 30;
  var isPeerFirefox = peerBrowserAgent === 'firefox';
  var isPeerFirefoxInterop = peerBrowserAgent === 'firefox' &&
    ((peerBrowserVersion) ? (peerBrowserVersion > 30) : false);

  // Resends an updated version of constraints for MozDataChannel to work
  // If other userAgent is firefox and user is firefox, remove MozDataChannel
  if ((isLocalFirefox && isPeerFirefox) || (isLocalFirefoxInterop)) {
    try {
      delete constraints.mandatory.MozDontOfferDataChannel;
    } catch (error) {
      console.error('Failed deleting MozDontOfferDataChannel');
      console.error(error);
    }
  } else if ((isLocalFirefox && !isPeerFirefox)) {
    constraints.mandatory.MozDontOfferDataChannel = true;
  }
  if (!isLocalFirefox) {
    // temporary measure to remove Moz* constraints in non Firefox browsers
    for (var prop in constraints.mandatory) {
      if (constraints.mandatory.hasOwnProperty(prop)) {
        if (prop.indexOf('Moz') !== -1) {
          delete constraints.mandatory[prop];
        }
      }
    }
  }
  // Firefox (not interopable) cannot offer DataChannel as it will cause problems to the
  // interopability of the media stream
  if (isLocalFirefox && !isPeerFirefox && !isLocalFirefoxInterop) {
    beOfferer = false;
  }
  callback(beOfferer, constraints);
};

// Handles the differences for all browsers ice connection state output.
// - Tested outcomes are:
//   - Chrome (offerer)  : 'checking' > 'completed' > 'completed'
//   - Chrome (answerer) : 'checking' > 'connected'
//   - Firefox (offerer) : 'checking' > 'connected'
//   - Firefox (answerer): 'checking' > 'connected'
checkIceConnectionState = function (peerId, iceConnectionState, callback) {
  if (typeof callback !== 'function') {
    console.warn('No callback specified in checkIceConnectionState. Aborted.');
    return;
  }
  peerId = (peerId) ? peerId : 'peer';

  if (!AdapterJS._iceConnectionFiredStates[peerId] ||
    iceConnectionState === AdapterJS._iceConnectionStates.disconnected ||
    iceConnectionState === AdapterJS._iceConnectionStates.failed ||
    iceConnectionState === AdapterJS._iceConnectionStates.closed) {
    AdapterJS._iceConnectionFiredStates[peerId] = [];
  }
  iceConnectionState = AdapterJS._iceConnectionStates[iceConnectionState];
  if (AdapterJS._iceConnectionFiredStates[peerId].indexOf(iceConnectionState) < 0) {
    AdapterJS._iceConnectionFiredStates[peerId].push(iceConnectionState);
    if (iceConnectionState === AdapterJS._iceConnectionStates.connected) {
      setTimeout(function () {
        AdapterJS._iceConnectionFiredStates[peerId]
          .push(AdapterJS._iceConnectionStates.done);
        callback(AdapterJS._iceConnectionStates.done);
      }, 1000);
    }
    callback(iceConnectionState);
  }
  return;
};

// Firefox:
// - Creates iceServer from the url for Firefox.
// - Create iceServer with stun url.
// - Create iceServer with turn url.
//   - Ignore the transport parameter from TURN url for FF version <=27.
//   - Return null for createIceServer if transport=tcp.
// - FF 27 and above supports transport parameters in TURN url,
// - So passing in the full url to create iceServer.
// Chrome:
// - Creates iceServer from the url for Chrome M33 and earlier.
//   - Create iceServer with stun url.
//   - Chrome M28 & above uses below TURN format.
// Plugin:
// - Creates Ice Server for Plugin Browsers
//   - If Stun - Create iceServer with stun url.
//   - Else - Create iceServer with turn url
//   - This is a WebRTC Function
createIceServer = null;

// Firefox:
// - Creates IceServers for Firefox
//   - Use .url for FireFox.
//   - Multiple Urls support
// Chrome:
// - Creates iceServers from the urls for Chrome M34 and above.
//   - .urls is supported since Chrome M34.
//   - Multiple Urls support
// Plugin:
// - Creates Ice Servers for Plugin Browsers
//   - Multiple Urls support
//   - This is a WebRTC Function
createIceServers = null;
//------------------------------------------------------------

//The RTCPeerConnection object.
RTCPeerConnection = null;

// Creates RTCSessionDescription object for Plugin Browsers
RTCSessionDescription = (typeof RTCSessionDescription === 'function') ?
  RTCSessionDescription : null;

// Creates RTCIceCandidate object for Plugin Browsers
RTCIceCandidate = (typeof RTCIceCandidate === 'function') ?
  RTCIceCandidate : null;

// Get UserMedia (only difference is the prefix).
// Code from Adam Barth.
getUserMedia = null;

// Attach a media stream to an element.
attachMediaStream = null;

// Re-attach a media stream to an element.
reattachMediaStream = null;


// Detected browser agent name. Types are:
// - 'firefox': Firefox browser.
// - 'chrome': Chrome browser.
// - 'opera': Opera browser.
// - 'safari': Safari browser.
// - 'IE' - Internet Explorer browser.
webrtcDetectedBrowser = null;

// Detected browser version.
webrtcDetectedVersion = null;

// Check for browser types and react accordingly
if (navigator.mozGetUserMedia) {
  webrtcDetectedBrowser = 'firefox';
  webrtcDetectedVersion = parseInt(navigator
    .userAgent.match(/Firefox\/([0-9]+)\./)[1], 10);
  webrtcDetectedType = 'moz';
  webrtcDetectedDCSupport = 'SCTP';

  RTCPeerConnection = function (pcConfig, pcConstraints) {
    AdapterJS.maybeFixConfiguration(pcConfig);
    return new mozRTCPeerConnection(pcConfig, pcConstraints);
  };

 // The RTCSessionDescription object.
  RTCSessionDescription = mozRTCSessionDescription;
  window.RTCSessionDescription = RTCSessionDescription;

  // The RTCIceCandidate object.
  RTCIceCandidate = mozRTCIceCandidate;
  window.RTCIceCandidate = RTCIceCandidate;

  window.getUserMedia = navigator.mozGetUserMedia.bind(navigator);
  navigator.getUserMedia = window.getUserMedia;

  // Shim for MediaStreamTrack.getSources.
  MediaStreamTrack.getSources = function(successCb) {
    setTimeout(function() {
      var infos = [
        { kind: 'audio', id: 'default', label:'', facing:'' },
        { kind: 'video', id: 'default', label:'', facing:'' }
      ];
      successCb(infos);
    }, 0);
  };

  createIceServer = function (url, username, password) {
    var iceServer = null;
    var url_parts = url.split(':');
    if (url_parts[0].indexOf('stun') === 0) {
      iceServer = { url : url };
    } else if (url_parts[0].indexOf('turn') === 0) {
      if (webrtcDetectedVersion < 27) {
        var turn_url_parts = url.split('?');
        if (turn_url_parts.length === 1 ||
          turn_url_parts[1].indexOf('transport=udp') === 0) {
          iceServer = {
            url : turn_url_parts[0],
            credential : password,
            username : username
          };
        }
      } else {
        iceServer = {
          url : url,
          credential : password,
          username : username
        };
      }
    }
    return iceServer;
  };

  createIceServers = function (urls, username, password) {
    var iceServers = [];
    for (var i = 0; i < urls.length; i++) {
      var iceServer = createIceServer(urls[i], username, password);
      if (iceServer !== null) {
        iceServers.push(iceServer);
      }
    }
    return iceServers;
  };

  attachMediaStream = function (element, stream) {
    element.mozSrcObject = stream;
    if (stream !== null)
      element.play();

    return element;
  };

  reattachMediaStream = function (to, from) {
    to.mozSrcObject = from.mozSrcObject;
    to.play();
    return to;
  };

  MediaStreamTrack.getSources = MediaStreamTrack.getSources || function (callback) {
    if (!callback) {
      throw new TypeError('Failed to execute \'getSources\' on \'MediaStreamTrack\'' +
        ': 1 argument required, but only 0 present.');
    }
    return callback([]);
  };

  // Fake get{Video,Audio}Tracks
  if (!MediaStream.prototype.getVideoTracks) {
    MediaStream.prototype.getVideoTracks = function () {
      return [];
    };
  }
  if (!MediaStream.prototype.getAudioTracks) {
    MediaStream.prototype.getAudioTracks = function () {
      return [];
    };
  }

  AdapterJS.maybeThroughWebRTCReady();
} else if (navigator.webkitGetUserMedia) {
  webrtcDetectedBrowser = 'chrome';
  webrtcDetectedType = 'webkit';
  webrtcDetectedVersion = parseInt(navigator
    .userAgent.match(/Chrom(e|ium)\/([0-9]+)\./)[2], 10);
  // check if browser is opera 20+
  var checkIfOpera = navigator.userAgent.match(/\bOPR\/(\d+)/);
  if (checkIfOpera !== null) {
    webrtcDetectedBrowser = 'opera';
    webrtcDetectedVersion = parseInt(checkIfOpera[1], 10);
  }
  // check browser datachannel support
  if ((webrtcDetectedBrowser === 'chrome' && webrtcDetectedVersion >= 31) ||
    (webrtcDetectedBrowser === 'opera' && webrtcDetectedVersion >= 20)) {
    webrtcDetectedDCSupport = 'SCTP';
  } else if (webrtcDetectedBrowser === 'chrome' && webrtcDetectedVersion < 30 &&
    webrtcDetectedVersion > 24) {
    webrtcDetectedDCSupport = 'RTP';
  } else {
    webrtcDetectedDCSupport = '';
  }

  createIceServer = function (url, username, password) {
    var iceServer = null;
    var url_parts = url.split(':');
    if (url_parts[0].indexOf('stun') === 0) {
      iceServer = { 'url' : url };
    } else if (url_parts[0].indexOf('turn') === 0) {
      iceServer = {
        'url' : url,
        'credential' : password,
        'username' : username
      };
    }
    return iceServer;
  };

  createIceServers = function (urls, username, password) {
    var iceServers = [];
    if (webrtcDetectedVersion >= 34) {
      iceServers = {
        'urls' : urls,
        'credential' : password,
        'username' : username
      };
    } else {
      for (var i = 0; i < urls.length; i++) {
        var iceServer = createIceServer(urls[i], username, password);
        if (iceServer !== null) {
          iceServers.push(iceServer);
        }
      }
    }
    return iceServers;
  };

  RTCPeerConnection = function (pcConfig, pcConstraints) {
    if (webrtcDetectedVersion < 34) {
      AdapterJS.maybeFixConfiguration(pcConfig);
    }
    return new webkitRTCPeerConnection(pcConfig, pcConstraints);
  };

  window.getUserMedia = navigator.webkitGetUserMedia.bind(navigator);
  navigator.getUserMedia = window.getUserMedia;

  attachMediaStream = function (element, stream) {
    if (typeof element.srcObject !== 'undefined') {
      element.srcObject = stream;
    } else if (typeof element.mozSrcObject !== 'undefined') {
      element.mozSrcObject = stream;
    } else if (typeof element.src !== 'undefined') {
      element.src = (stream === null ? '' : URL.createObjectURL(stream));
    } else {
      console.log('Error attaching stream to element.');
    }
    return element;
  };

  reattachMediaStream = function (to, from) {
    to.src = from.src;
    return to;
  };

  AdapterJS.maybeThroughWebRTCReady();
} else if (navigator.mediaDevices && navigator.userAgent.match(
    /Edge\/(\d+).(\d+)$/)) {
  webrtcDetectedBrowser = 'edge';

  webrtcDetectedVersion =
    parseInt(navigator.userAgent.match(/Edge\/(\d+).(\d+)$/)[2], 10);

  // the minimum version still supported by adapter.
  webrtcMinimumVersion = 12;

  window.getUserMedia = navigator.getUserMedia.bind(navigator);

  attachMediaStream = function(element, stream) {
    element.srcObject = stream;
    return element;
  };
  reattachMediaStream = function(to, from) {
    to.srcObject = from.srcObject;
    return to;
  };

  AdapterJS.maybeThroughWebRTCReady();
} else { // TRY TO USE PLUGIN
  // IE 9 is not offering an implementation of console.log until you open a console
  if (typeof console !== 'object' || typeof console.log !== 'function') {
    /* jshint -W020 */
    console = {} || console;
    // Implemented based on console specs from MDN
    // You may override these functions
    console.log = function (arg) {};
    console.info = function (arg) {};
    console.error = function (arg) {};
    console.dir = function (arg) {};
    console.exception = function (arg) {};
    console.trace = function (arg) {};
    console.warn = function (arg) {};
    console.count = function (arg) {};
    console.debug = function (arg) {};
    console.count = function (arg) {};
    console.time = function (arg) {};
    console.timeEnd = function (arg) {};
    console.group = function (arg) {};
    console.groupCollapsed = function (arg) {};
    console.groupEnd = function (arg) {};
    /* jshint +W020 */
  }
  webrtcDetectedType = 'plugin';
  webrtcDetectedDCSupport = 'plugin';
  AdapterJS.parseWebrtcDetectedBrowser();
  isIE = webrtcDetectedBrowser === 'IE';

  /* jshint -W035 */
  AdapterJS.WebRTCPlugin.WaitForPluginReady = function() {
    while (AdapterJS.WebRTCPlugin.pluginState !== AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      /* empty because it needs to prevent the function from running. */
    }
  };
  /* jshint +W035 */

  AdapterJS.WebRTCPlugin.callWhenPluginReady = function (callback) {
    if (AdapterJS.WebRTCPlugin.pluginState === AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      // Call immediately if possible
      // Once the plugin is set, the code will always take this path
      callback();
    } else {
      // otherwise start a 100ms interval
      var checkPluginReadyState = setInterval(function () {
        if (AdapterJS.WebRTCPlugin.pluginState === AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
          clearInterval(checkPluginReadyState);
          callback();
        }
      }, 100);
    }
  };

  AdapterJS.WebRTCPlugin.setLogLevel = function(logLevel) {
    AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
      AdapterJS.WebRTCPlugin.plugin.setLogLevel(logLevel);
    });
  };

  AdapterJS.WebRTCPlugin.injectPlugin = function () {
    // only inject once the page is ready
    if (document.readyState !== 'complete') {
      return;
    }

    // Prevent multiple injections
    if (AdapterJS.WebRTCPlugin.pluginState !== AdapterJS.WebRTCPlugin.PLUGIN_STATES.INITIALIZING) {
      return;
    }

    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INJECTING;

    if (webrtcDetectedBrowser === 'IE' && webrtcDetectedVersion <= 10) {
      var frag = document.createDocumentFragment();
      AdapterJS.WebRTCPlugin.plugin = document.createElement('div');
      AdapterJS.WebRTCPlugin.plugin.innerHTML = '<object id="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '" type="' +
        AdapterJS.WebRTCPlugin.pluginInfo.type + '" ' + 'width="1" height="1">' +
        '<param name="pluginId" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '" /> ' +
        '<param name="windowless" value="false" /> ' +
        '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '" /> ' +
        '<param name="onload" value="' + AdapterJS.WebRTCPlugin.pluginInfo.onload + '" />' +
        '<param name="tag" value="' + AdapterJS.WebRTCPlugin.TAGS.NONE + '" />' +
        // uncomment to be able to use virtual cams
        (AdapterJS.options.getAllCams ? '<param name="forceGetAllCams" value="True" />':'') +

        '</object>';
      while (AdapterJS.WebRTCPlugin.plugin.firstChild) {
        frag.appendChild(AdapterJS.WebRTCPlugin.plugin.firstChild);
      }
      document.body.appendChild(frag);

      // Need to re-fetch the plugin
      AdapterJS.WebRTCPlugin.plugin =
        document.getElementById(AdapterJS.WebRTCPlugin.pluginInfo.pluginId);
    } else {
      // Load Plugin
      AdapterJS.WebRTCPlugin.plugin = document.createElement('object');
      AdapterJS.WebRTCPlugin.plugin.id =
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId;
      // IE will only start the plugin if it's ACTUALLY visible
      if (isIE) {
        AdapterJS.WebRTCPlugin.plugin.width = '1px';
        AdapterJS.WebRTCPlugin.plugin.height = '1px';
      } else { // The size of the plugin on Safari should be 0x0px
              // so that the autorisation prompt is at the top
        AdapterJS.WebRTCPlugin.plugin.width = '0px';
        AdapterJS.WebRTCPlugin.plugin.height = '0px';
      }
      AdapterJS.WebRTCPlugin.plugin.type = AdapterJS.WebRTCPlugin.pluginInfo.type;
      AdapterJS.WebRTCPlugin.plugin.innerHTML = '<param name="onload" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.onload + '">' +
        '<param name="pluginId" value="' +
        AdapterJS.WebRTCPlugin.pluginInfo.pluginId + '">' +
        '<param name="windowless" value="false" /> ' +
        (AdapterJS.options.getAllCams ? '<param name="forceGetAllCams" value="True" />':'') +
        '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '">' +
        '<param name="tag" value="' + AdapterJS.WebRTCPlugin.TAGS.NONE + '" />';
      document.body.appendChild(AdapterJS.WebRTCPlugin.plugin);
    }


    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INJECTED;
  };

  AdapterJS.WebRTCPlugin.isPluginInstalled =
    function (comName, plugName, installedCb, notInstalledCb) {
    if (!isIE) {
      var pluginArray = navigator.plugins;
      for (var i = 0; i < pluginArray.length; i++) {
        if (pluginArray[i].name.indexOf(plugName) >= 0) {
          installedCb();
          return;
        }
      }
      notInstalledCb();
    } else {
      try {
        var axo = new ActiveXObject(comName + '.' + plugName);
      } catch (e) {
        notInstalledCb();
        return;
      }
      installedCb();
    }
  };

  AdapterJS.WebRTCPlugin.defineWebRTCInterface = function () {
    if (AdapterJS.WebRTCPlugin.pluginState ===
        AdapterJS.WebRTCPlugin.PLUGIN_STATES.READY) {
      console.error("AdapterJS - WebRTC interface has already been defined");
      return;
    }

    AdapterJS.WebRTCPlugin.pluginState = AdapterJS.WebRTCPlugin.PLUGIN_STATES.INITIALIZING;

    AdapterJS.isDefined = function (variable) {
      return variable !== null && variable !== undefined;
    };

    createIceServer = function (url, username, password) {
      var iceServer = null;
      var url_parts = url.split(':');
      if (url_parts[0].indexOf('stun') === 0) {
        iceServer = {
          'url' : url,
          'hasCredentials' : false
        };
      } else if (url_parts[0].indexOf('turn') === 0) {
        iceServer = {
          'url' : url,
          'hasCredentials' : true,
          'credential' : password,
          'username' : username
        };
      }
      return iceServer;
    };

    createIceServers = function (urls, username, password) {
      var iceServers = [];
      for (var i = 0; i < urls.length; ++i) {
        iceServers.push(createIceServer(urls[i], username, password));
      }
      return iceServers;
    };

    RTCSessionDescription = function (info) {
      AdapterJS.WebRTCPlugin.WaitForPluginReady();
      return AdapterJS.WebRTCPlugin.plugin.
        ConstructSessionDescription(info.type, info.sdp);
    };

    RTCPeerConnection = function (servers, constraints) {
      var iceServers = null;
      if (servers) {
        iceServers = servers.iceServers;
        for (var i = 0; i < iceServers.length; i++) {
          if (iceServers[i].urls && !iceServers[i].url) {
            iceServers[i].url = iceServers[i].urls;
          }
          iceServers[i].hasCredentials = AdapterJS.
            isDefined(iceServers[i].username) &&
            AdapterJS.isDefined(iceServers[i].credential);
        }
      }
      var mandatory = (constraints && constraints.mandatory) ?
        constraints.mandatory : null;
      var optional = (constraints && constraints.optional) ?
        constraints.optional : null;

      AdapterJS.WebRTCPlugin.WaitForPluginReady();
      return AdapterJS.WebRTCPlugin.plugin.
        PeerConnection(AdapterJS.WebRTCPlugin.pageId,
        iceServers, mandatory, optional);
    };

    MediaStreamTrack = {};
    MediaStreamTrack.getSources = function (callback) {
      AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
        AdapterJS.WebRTCPlugin.plugin.GetSources(callback);
      });
    };

    window.getUserMedia = function (constraints, successCallback, failureCallback) {
      constraints.audio = constraints.audio || false;
      constraints.video = constraints.video || false;

      AdapterJS.WebRTCPlugin.callWhenPluginReady(function() {
        AdapterJS.WebRTCPlugin.plugin.
          getUserMedia(constraints, successCallback, failureCallback);
      });
    };
    window.navigator.getUserMedia = window.getUserMedia;

    attachMediaStream = function (element, stream) {
      if (!element || !element.parentNode) {
        return;
      }

      var streamId;
      if (stream === null) {
        streamId = '';
      } else {
        if (typeof stream.enableSoundTracks !== 'undefined') {
          stream.enableSoundTracks(true);
        }
        streamId = stream.id;
      }

      var elementId = element.id.length === 0 ? Math.random().toString(36).slice(2) : element.id;
      var nodeName = element.nodeName.toLowerCase();
      if (nodeName !== 'object') { // not a plugin <object> tag yet
        var tag;
        switch(nodeName) {
          case 'audio':
            tag = AdapterJS.WebRTCPlugin.TAGS.AUDIO;
            break;
          case 'video':
            tag = AdapterJS.WebRTCPlugin.TAGS.VIDEO;
            break;
          default:
            tag = AdapterJS.WebRTCPlugin.TAGS.NONE;
          }

        var frag = document.createDocumentFragment();
        var temp = document.createElement('div');
        var classHTML = '';
        if (element.className) {
          classHTML = 'class="' + element.className + '" ';
        } else if (element.attributes && element.attributes['class']) {
          classHTML = 'class="' + element.attributes['class'].value + '" ';
        }

        temp.innerHTML = '<object id="' + elementId + '" ' + classHTML +
          'type="' + AdapterJS.WebRTCPlugin.pluginInfo.type + '">' +
          '<param name="pluginId" value="' + elementId + '" /> ' +
          '<param name="pageId" value="' + AdapterJS.WebRTCPlugin.pageId + '" /> ' +
          '<param name="windowless" value="true" /> ' +
          '<param name="streamId" value="' + streamId + '" /> ' +
          '<param name="tag" value="' + tag + '" /> ' +
          '</object>';
        while (temp.firstChild) {
          frag.appendChild(temp.firstChild);
        }

        var height = '';
        var width = '';
        if (element.clientWidth || element.clientHeight) {
          width = element.clientWidth;
          height = element.clientHeight;
        }
        else if (element.width || element.height) {
          width = element.width;
          height = element.height;
        }

        element.parentNode.insertBefore(frag, element);
        frag = document.getElementById(elementId);
        frag.width = width;
        frag.height = height;
        element.parentNode.removeChild(element);
      } else { // already an <object> tag, just change the stream id
        var children = element.children;
        for (var i = 0; i !== children.length; ++i) {
          if (children[i].name === 'streamId') {
            children[i].value = streamId;
            break;
          }
        }
        element.setStreamId(streamId);
      }
      var newElement = document.getElementById(elementId);
      AdapterJS.forwardEventHandlers(newElement, element, Object.getPrototypeOf(element));

      return newElement;
    };

    reattachMediaStream = function (to, from) {
      var stream = null;
      var children = from.children;
      for (var i = 0; i !== children.length; ++i) {
        if (children[i].name === 'streamId') {
          AdapterJS.WebRTCPlugin.WaitForPluginReady();
          stream = AdapterJS.WebRTCPlugin.plugin
            .getStreamWithId(AdapterJS.WebRTCPlugin.pageId, children[i].value);
          break;
        }
      }
      if (stream !== null) {
        return attachMediaStream(to, stream);
      } else {
        console.log('Could not find the stream associated with this element');
      }
    };

    AdapterJS.forwardEventHandlers = function (destElem, srcElem, prototype) {

      properties = Object.getOwnPropertyNames( prototype );

      for(prop in properties) {
        propName = properties[prop];

        if (typeof(propName.slice) === 'function') {
          if (propName.slice(0,2) == 'on' && srcElem[propName] != null) {
            if (isIE) {
              destElem.attachEvent(propName,srcElem[propName]);
            } else {
              destElem.addEventListener(propName.slice(2), srcElem[propName], false)
            }
          } else {
            //TODO (http://jira.temasys.com.sg/browse/TWP-328) Forward non-event properties ?
          }
        }
      }

      var subPrototype = Object.getPrototypeOf(prototype)
      if(subPrototype != null) {
        AdapterJS.forwardEventHandlers(destElem, srcElem, subPrototype);
      }
    }

    RTCIceCandidate = function (candidate) {
      if (!candidate.sdpMid) {
        candidate.sdpMid = '';
      }

      AdapterJS.WebRTCPlugin.WaitForPluginReady();
      return AdapterJS.WebRTCPlugin.plugin.ConstructIceCandidate(
        candidate.sdpMid, candidate.sdpMLineIndex, candidate.candidate
      );
    };

    // inject plugin
    AdapterJS.addEvent(document, 'readystatechange', AdapterJS.WebRTCPlugin.injectPlugin);
    AdapterJS.WebRTCPlugin.injectPlugin();
  };

  // This function will be called if the plugin is needed (browser different
  // from Chrome or Firefox), but the plugin is not installed.
  AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb = AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb ||
    function() {
      AdapterJS.addEvent(document,
                        'readystatechange',
                         AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv);
      AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv();
    };

  AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCbPriv = function () {
    if (AdapterJS.options.hidePluginInstallPrompt) {
      return;
    }

    var downloadLink = AdapterJS.WebRTCPlugin.pluginInfo.downloadLink;
    if(downloadLink) { // if download link
      var popupString;
      if (AdapterJS.WebRTCPlugin.pluginInfo.portalLink) { // is portal link
       popupString = 'This website requires you to install the ' +
        ' <a href="' + AdapterJS.WebRTCPlugin.pluginInfo.portalLink +
        '" target="_blank">' + AdapterJS.WebRTCPlugin.pluginInfo.companyName +
        ' WebRTC Plugin</a>' +
        ' to work on this browser.';
      } else { // no portal link, just print a generic explanation
       popupString = AdapterJS.TEXT.PLUGIN.REQUIRE_INSTALLATION;
      }

      AdapterJS.renderNotificationBar(popupString, AdapterJS.TEXT.PLUGIN.BUTTON, downloadLink);
    } else { // no download link, just print a generic explanation
      AdapterJS.renderNotificationBar(AdapterJS.TEXT.PLUGIN.NOT_SUPPORTED);
    }
  };

  // Try to detect the plugin and act accordingly
  AdapterJS.WebRTCPlugin.isPluginInstalled(
    AdapterJS.WebRTCPlugin.pluginInfo.prefix,
    AdapterJS.WebRTCPlugin.pluginInfo.plugName,
    AdapterJS.WebRTCPlugin.defineWebRTCInterface,
    AdapterJS.WebRTCPlugin.pluginNeededButNotInstalledCb);
}