cleanup desktopsharing events

app.js

 import RoomnameGenerator from './modules/util/RoomnameGenerator';
 import CQEvents from './service/connectionquality/CQEvents';
 import UIEvents from './service/UI/UIEvents';
+import DSEvents from './service/desktopsharing/DesktopSharingEventTypes';
 
 import UI from "./modules/UI/UI";
 import statistics from "./modules/statistics/statistics";
 
 import createRoomLocker from './modules/RoomLocker';
 
-const DesktopSharingEventTypes =
-    require("./service/desktopsharing/DesktopSharingEventTypes");
-
 const ConnectionEvents = JitsiMeetJS.events.connection;
 const ConnectionErrors = JitsiMeetJS.errors.connection;
 
         APP.UI.updateDTMFSupport(isDTMFSupported);
     });
 
+    APP.UI.addListener(UIEvents.TOGGLE_SCREENSHARING, function () {
+        APP.desktopsharing.toggleScreenSharing();
+    });
+    APP.UI.addListener(DSEvents.SWITCHING_DONE, function (isSharingScreen) {
+        APP.UI.updateDesktopSharingButtons(isSharingScreen);
+    });
     APP.desktopsharing.addListener(
-        DesktopSharingEventTypes.NEW_STREAM_CREATED,
+        DSEvents.NEW_STREAM_CREATED,
         (track, callback) => {
             const localCallback = (newTrack) => {
                 if (newTrack.isLocal() && newTrack === localVideo) {

modules/UI/UI.js

 import PanelToggler from "./side_pannels/SidePanelToggler";
 import UIUtil from "./util/UIUtil";
 import UIEvents from "../../service/UI/UIEvents";
+import CQEvents from '../../service/connectionquality/CQEvents';
 import PreziManager from './prezi/Prezi';
 import EtherpadManager from './etherpad/Etherpad';
 
 UI.messageHandler = require("./util/MessageHandler");
 var messageHandler = UI.messageHandler;
 var JitsiPopover = require("./util/JitsiPopover");
-var CQEvents = require("../../service/connectionquality/CQEvents");
-var DesktopSharingEventTypes
-    = require("../../service/desktopsharing/DesktopSharingEventTypes");
 var Feedback = require("./Feedback");
 
 var eventEmitter = new EventEmitter();
     VideoLayout.setAudioLevel(id, lvl);
 };
 
-UI.updateDesktopSharingButtons = function () {
-    Toolbar.changeDesktopSharingButtonState();
+UI.updateDesktopSharingButtons = function (isSharingScreen) {
+    Toolbar.changeDesktopSharingButtonState(isSharingScreen);
 };
 
 UI.hideStats = function () {

modules/UI/toolbars/Toolbar.js

         } else {
             AnalyticsAdapter.sendEvent('toolbar.screen.enabled');
         }
-        APP.desktopsharing.toggleScreenSharing();
+        emitter.emit(UIEvents.TOGGLE_SCREENSHARING);
     },
     "toolbar_button_fullScreen": function() {
         AnalyticsAdapter.sendEvent('toolbar.fullscreen.enabled');
     // checks whether desktop sharing is enabled and whether
     // we have params to start automatically sharing
     checkAutoEnableDesktopSharing () {
-        if (UIUtil.isButtonEnabled('desktop')
-            && config.autoEnableDesktopSharing) {
-            APP.desktopsharing.toggleScreenSharing();
+        if (UIUtil.isButtonEnabled('desktop') && config.autoEnableDesktopSharing) {
+            emitter.emit(UIEvents.TOGGLE_SCREENSHARING);
         }
     },
 

modules/desktopsharing/desktopsharing.js

 /* global APP, JitsiMeetJS, config */
 var EventEmitter = require("events");
-var DesktopSharingEventTypes
-    = require("../../service/desktopsharing/DesktopSharingEventTypes");
+import DSEvents from '../../service/desktopsharing/DesktopSharingEventTypes';
 
 const TrackEvents = JitsiMeetJS.events.track;
 
 
 function streamSwitchDone() {
     switchInProgress = false;
-    eventEmitter.emit(
-        DesktopSharingEventTypes.SWITCHING_DONE,
-        isUsingScreenStream);
+    eventEmitter.emit(DSEvents.SWITCHING_DONE, isUsingScreenStream);
 }
 
 function newStreamCreated(track) {
-    eventEmitter.emit(DesktopSharingEventTypes.NEW_STREAM_CREATED,
-        track, streamSwitchDone);
+    eventEmitter.emit(DSEvents.NEW_STREAM_CREATED, track, streamSwitchDone);
 }
 
 function getVideoStreamFailed() {

service/UI/UIEvents.js

     TOGGLE_SETTINGS: "UI.toggle_settings",
     TOGGLE_CONTACT_LIST: "UI.toggle_contact_list",
     TOGGLE_FILM_STRIP: "UI.toggle_film_strip",
+    TOGGLE_SCREENSHARING: "UI.toggle_screensharing",
     CONTACT_CLICKED: "UI.contact_clicked",
     HANGUP: "UI.hangup",
     LOGOUT: "UI.logout",

service/desktopsharing/DesktopSharingEventTypes.js

-var DesktopSharingEventTypes = {
-    INIT: "ds.init",
-
+export default {
     SWITCHING_DONE: "ds.switching_done",
 
     NEW_STREAM_CREATED: "ds.new_stream_created",
      */
     FIREFOX_EXTENSION_NEEDED: "ds.firefox_extension_needed"
 };
-
-module.exports = DesktopSharingEventTypes;