abstract out remoteVideos management

modules/UI/UI.js

 function setupToolbars() {
     Toolbar.init(eventEmitter);
     Toolbar.setupButtonsFromConfig();
-    BottomToolbar.init(eventEmitter);
+    BottomToolbar.setupListeners(eventEmitter);
 }
 
 /**
 
     registerListeners();
 
+    BottomToolbar.init();
+
     VideoLayout.init(eventEmitter);
     if (!interfaceConfig.filmStripOnly) {
         VideoLayout.initLargeVideo(PanelToggler.isVisible());
         $("#header").css("display", "none");
         $("#bottomToolbar").css("display", "none");
         $("#downloadlog").css("display", "none");
-        $("#remoteVideos").css("padding", "0px 0px 18px 0px");
-        $("#remoteVideos").css("right", "0px");
+        BottomToolbar.setupFilmStripOnly();
         messageHandler.disableNotifications();
         $('body').popover("disable");
         JitsiPopover.enabled = false;

modules/UI/audio_levels/AudioLevels.js

 /* jshint -W101 */
 
 import CanvasUtil from './CanvasUtils';
+import BottomToolbar from '../toolbars/BottomToolbar';
 
 const LOCAL_LEVEL = 'local';
 
      * Updates the audio level canvas for the given id. If the canvas
      * didn't exist we create it.
      */
-    updateAudioLevelCanvas (id, VideoLayout) {
+    updateAudioLevelCanvas (id, thumbWidth, thumbHeight) {
         let videoSpanId = 'localVideoContainer';
         if (id) {
             videoSpanId = `participant_${id}`;
 
         let audioLevelCanvas = $(`#${videoSpanId}>canvas`);
 
-        let videoSpaceWidth = $('#remoteVideos').width();
-        let thumbnailSize = VideoLayout.calculateThumbnailSize(videoSpaceWidth);
-        let thumbnailWidth = thumbnailSize[0];
-        let thumbnailHeight = thumbnailSize[1];
-
         if (!audioLevelCanvas || audioLevelCanvas.length === 0) {
 
             audioLevelCanvas = document.createElement('canvas');
             audioLevelCanvas.className = "audiolevel";
             audioLevelCanvas.style.bottom = `-${interfaceConfig.CANVAS_EXTRA/2}px`;
             audioLevelCanvas.style.left = `-${interfaceConfig.CANVAS_EXTRA/2}px`;
-            resizeAudioLevelCanvas(audioLevelCanvas, thumbnailWidth, thumbnailHeight);
+            resizeAudioLevelCanvas(audioLevelCanvas, thumbWidth, thumbHeight);
 
             videoSpan.appendChild(audioLevelCanvas);
         } else {
             audioLevelCanvas = audioLevelCanvas.get(0);
 
-            resizeAudioLevelCanvas(audioLevelCanvas, thumbnailWidth, thumbnailHeight);
+            resizeAudioLevelCanvas(audioLevelCanvas, thumbWidth, thumbHeight);
         }
     },
 
         ASDrawContext.fill();
     },
 
-    /**
-     * Indicates that the remote video has been resized.
-     */
-    onRemoteVideoResized (width, height) {
-        let resized = false;
-
-        $('#remoteVideos>span>canvas').each(function() {
-            let canvas = $(this).get(0);
-            if (canvas.width !== width + interfaceConfig.CANVAS_EXTRA) {
-                canvas.width = width + interfaceConfig.CANVAS_EXTRA;
-                resized = true;
-            }
+    updateCanvasSize (thumbWidth, thumbHeight) {
+        let canvasWidth = thumbWidth + interfaceConfig.CANVAS_EXTRA;
+        let canvasHeight = thumbHeight + interfaceConfig.CANVAS_EXTRA;
 
-            if (canvas.height !== height + interfaceConfig.CANVAS_EXTRA) {
-                canvas.height = height + interfaceConfig.CANVAS_EXTRA;
-                resized = true;
-            }
-        });
+        BottomToolbar.getThumbs().children('canvas').width(canvasWidth).height(canvasHeight);
 
-        if (resized) {
-            Object.keys(audioLevelCanvasCache).forEach(function (id) {
-                audioLevelCanvasCache[id].width = width + interfaceConfig.CANVAS_EXTRA;
-                audioLevelCanvasCache[id].height = height + interfaceConfig.CANVAS_EXTRA;
-            });
-        }
+        Object.keys(audioLevelCanvasCache).forEach(function (id) {
+            audioLevelCanvasCache[id].width = canvasWidth;
+            audioLevelCanvasCache[id].height = canvasHeight;
+        });
     }
 };
 

modules/UI/etherpad/Etherpad.js

 import LargeContainer from '../videolayout/LargeContainer';
 import UIUtil from "../util/UIUtil";
 import SidePanelToggler from "../side_pannels/SidePanelToggler";
+import BottomToolbar from '../toolbars/BottomToolbar';
 
 const options = $.param({
     showControns: true,
     }
 
     resize (containerWidth, containerHeight, animate) {
-        let remoteVideos = $('#remoteVideos');
-
-        let height = containerHeight - remoteVideos.outerHeight();
+        let height = containerHeight - BottomToolbar.getFilmStripHeight();
         let width = containerWidth;
 
         $(this.iframe).width(width).height(height);

modules/UI/prezi/Prezi.js

 import messageHandler from '../util/MessageHandler';
 import ToolbarToggler from "../toolbars/ToolbarToggler";
 import SidePanelToggler from "../side_pannels/SidePanelToggler";
+import BottomToolbar from '../toolbars/BottomToolbar';
 
 const defaultPreziLink = "http://prezi.com/wz7vhjycl7e6/my-prezi";
 const alphanumRegex = /^[a-z0-9-_\/&\?=;]+$/i;
     }
 
     resize (containerWidth, containerHeight) {
-        let remoteVideos = $('#remoteVideos');
-        let height = containerHeight - remoteVideos.outerHeight();
+        let height = containerHeight - BottomToolbar.getFilmStripHeight();
 
         let width = containerWidth;
 

modules/UI/toolbars/BottomToolbar.js

 };
 
 const BottomToolbar = {
-    init (emitter) {
+    init () {
+        this.filmStrip = $('#remoteVideos');
+        this.toolbar = $('#bottomToolbar');
+    },
+
+    setupListeners (emitter) {
         UIUtil.hideDisabledButtons(defaultBottomToolbarButtons);
 
         const buttonHandlers = {
     },
 
     toggleFilmStrip () {
-        $("#remoteVideos").toggleClass("hidden");
+        this.filmStrip.toggleClass("hidden");
+    },
+
+    isFilmStripVisible () {
+        return !this.filmStrip.hasClass('hidden');
+    },
+
+    setupFilmStripOnly () {
+        this.filmStrip.css({
+            padding: "0px 0px 18px 0px",
+            right: 0
+        });
+    },
+
+    getFilmStripHeight () {
+        if (this.isFilmStripVisible()) {
+            return this.filmStrip.outerHeight();
+        } else {
+            return 0;
+        }
+    },
+
+    getFilmStripWidth () {
+        return this.filmStrip.width();
+    },
+
+    resizeThumbnails (thumbWidth, thumbHeight, animate = false) {
+        return new Promise(resolve => {
+            this.filmStrip.animate({
+                // adds 2 px because of small video 1px border
+                height: thumbHeight + 2
+            }, {
+                queue: false,
+                duration: animate ? 500 : 0
+            });
+
+            this.getThumbs().animate({
+                height: thumbHeight,
+                width: thumbWidth
+            }, {
+                queue: false,
+                duration: animate ? 500 : 0,
+                complete:  resolve
+            });
+
+            if (!animate) {
+                resolve();
+            }
+        });
+    },
+
+    resizeToolbar (thumbWidth, thumbHeight) {
+        let bottom = (thumbHeight - this.toolbar.outerHeight())/2 + 18;
+        this.toolbar.css({bottom});
     },
 
-    onRemoteVideoResized (width, height) {
-        let toolbar = $('#bottomToolbar');
-        let bottom = (height - toolbar.outerHeight())/2 + 18;
+    getThumbs (visible = false) {
+        let selector = 'span';
+        if (visible) {
+            selector += ':visible';
+        }
 
-        toolbar.css({bottom});
+        return this.filmStrip.children(selector);
     }
 };
 

modules/UI/toolbars/ToolbarToggler.js

 /* global APP, config, $, interfaceConfig */
 
 import UIUtil from '../util/UIUtil';
+import BottomToolbar from './BottomToolbar';
 
 let toolbarTimeoutObject;
 let toolbarTimeout = interfaceConfig.INITIAL_TOOLBAR_TIMEOUT;
     } else {
         header.hide("slide", { direction: "up", duration: 300});
         $('#subject').animate({top: "-=40"}, 300);
-        if ($("#remoteVideos").hasClass("hidden")) {
+        if (!BottomToolbar.isFilmStripVisible()) {
             bottomToolbar.hide(
                 "slide", {direction: "right", duration: 300}
             );

modules/UI/videolayout/LargeVideo.js

 import UIUtil from "../util/UIUtil";
 import UIEvents from "../../../service/UI/UIEvents";
 import LargeContainer from './LargeContainer';
+import BottomToolbar from '../toolbars/BottomToolbar';
 
 const RTCBrowserType = require("../../RTC/RTCBrowserType");
 
     let availableWidth = Math.max(videoWidth, videoSpaceWidth);
     let availableHeight = Math.max(videoHeight, videoSpaceHeight);
 
-    let filmstrip = $("#remoteVideos");
-
-    if (!filmstrip.hasClass("hidden"))
-        videoSpaceHeight -= filmstrip.outerHeight();
+    videoSpaceHeight -= BottomToolbar.getFilmStripHeight();
 
     if (availableWidth / aspectRatio >= videoSpaceHeight) {
         availableHeight = videoSpaceHeight;

modules/UI/videolayout/RemoteVideo.js

     if (APP.conference.isModerator) {
         this.addRemoteVideoMenu();
     }
-    AudioLevels.updateAudioLevelCanvas(this.id, this.VideoLayout);
+    let {thumbWidth, thumbHeight} = this.VideoLayout.calculateThumbnailSize();
+    AudioLevels.updateAudioLevelCanvas(this.id, thumbWidth, thumbHeight);
 
     return this.container;
 };

modules/UI/videolayout/VideoLayout.js

  */
 var focusedVideoResourceJid = null;
 
+const thumbAspectRatio = 16.0 / 9.0;
+
 /**
  * On contact list item clicked.
  */
         let localId = APP.conference.localId;
         this.onVideoTypeChanged(localId, stream.getType());
 
-        AudioLevels.updateAudioLevelCanvas(null, VideoLayout);
+        let {thumbWidth, thumbHeight} = this.calculateThumbnailSize();
+        AudioLevels.updateAudioLevelCanvas(null, thumbWidth, thumbHeight);
 
         localVideoThumbnail.changeVideo(stream);
 
     electLastVisibleVideo () {
         // pick the last visible video in the row
         // if nobody else is left, this picks the local video
-        let pick = $('#remoteVideos>span[id!="mixedstream"]:visible:last');
-        if (pick.length) {
-            let id = getPeerContainerResourceId(pick[0]);
+        let thumbs = BottomToolbar.getThumbs(true).filter('id!="mixedstream"');
+
+        let lastVisible = thumbs.filter(':visible:last');
+        if (lastVisible.length) {
+            let id = getPeerContainerResourceId(lastVisible[0]);
             if (remoteVideos[id]) {
                 console.info("electLastVisibleVideo: " + id);
                 return id;
         }
 
         console.info("Last visible video no longer exists");
-        pick = $('#remoteVideos>span[id!="mixedstream"]');
-        if (pick.length) {
-            let id = getPeerContainerResourceId(pick[0]);
+        thumbs = BottomToolbar.getThumbs();
+        if (thumbs.length) {
+            let id = getPeerContainerResourceId(thumbs[0]);
             if (remoteVideos[id]) {
                 console.info("electLastVisibleVideo: " + id);
                 return id;
 
         // In case this is not currently in the last n we don't show it.
         if (localLastNCount && localLastNCount > 0 &&
-            $('#remoteVideos>span').length >= localLastNCount + 2) {
+            BottomToolbar.getThumbs().length >= localLastNCount + 2) {
             remoteVideo.showPeerContainer('hide');
         } else {
             VideoLayout.resizeThumbnails();
      * Resizes thumbnails.
      */
     resizeThumbnails (animate = false) {
-        let videoSpaceWidth = $('#remoteVideos').width();
+        let {thumbWidth, thumbHeight} = this.calculateThumbnailSize();
 
-        let [width, height] = this.calculateThumbnailSize(videoSpaceWidth);
+        $('.userAvatar').css('left', (thumbWidth - thumbHeight) / 2);
 
-        $('.userAvatar').css('left', (width - height) / 2);
-
-        $('#remoteVideos').animate({
-            // adds 2 px because of small video 1px border
-            height: height + 2
-        }, {
-            queue: false,
-            duration: animate ? 500 : 0
-        });
-
-        $('#remoteVideos>span').animate({
-            height, width
-        }, {
-            queue: false,
-            duration: animate ? 500 : 0,
-            complete: function () {
-                BottomToolbar.onRemoteVideoResized(width, height);
-                AudioLevels.onRemoteVideoResized(width, height);
-            }
+        BottomToolbar.resizeThumbnails(thumbWidth, thumbHeight, animate).then(function () {
+            BottomToolbar.resizeToolbar(thumbWidth, thumbHeight);
+            AudioLevels.updateCanvasSize(thumbWidth, thumbHeight);
         });
     },
 
     /**
      * Calculates the thumbnail size.
      *
-     * @param videoSpaceWidth the width of the video space
      */
-    calculateThumbnailSize (videoSpaceWidth) {
+    calculateThumbnailSize () {
+        let videoSpaceWidth = BottomToolbar.getFilmStripWidth();
         // Calculate the available height, which is the inner window height
         // minus 39px for the header minus 2px for the delimiter lines on the
         // top and bottom of the large video, minus the 36px space inside the
         // remoteVideos container used for highlighting shadow.
-       var availableHeight = 100;
+        let availableHeight = 100;
 
-        var numvids = $('#remoteVideos>span:visible').length;
+        let numvids = BottomToolbar.getThumbs().length;
         if (localLastNCount && localLastNCount > 0) {
             numvids = Math.min(localLastNCount + 1, numvids);
         }
 
-       // Remove the 3px borders arround videos and border around the remote
-       // videos area and the 4 pixels between the local video and the others
-       //TODO: Find out where the 4 pixels come from and remove them
-       var availableWinWidth = videoSpaceWidth - 2 * 3 * numvids - 70 - 4;
+        // Remove the 3px borders arround videos and border around the remote
+        // videos area and the 4 pixels between the local video and the others
+        //TODO: Find out where the 4 pixels come from and remove them
+        let availableWinWidth = videoSpaceWidth - 2 * 3 * numvids - 70 - 4;
 
-       var availableWidth = availableWinWidth / numvids;
-       var aspectRatio = 16.0 / 9.0;
-       var maxHeight = Math.min(160, availableHeight);
-       availableHeight
-           = Math.min(  maxHeight,
-                        availableWidth / aspectRatio,
-                        window.innerHeight - 18);
+        let availableWidth = availableWinWidth / numvids;
+        let maxHeight = Math.min(160, availableHeight);
+        availableHeight
+            = Math.min(  maxHeight,
+                         availableWidth / thumbAspectRatio,
+                         window.innerHeight - 18);
 
-       if (availableHeight < availableWidth / aspectRatio) {
-           availableWidth = Math.floor(availableHeight * aspectRatio);
-       }
+        if (availableHeight < availableWidth / thumbAspectRatio) {
+            availableWidth = Math.floor(availableHeight * thumbAspectRatio);
+        }
 
-       return [availableWidth, availableHeight];
+        return {
+            thumbWidth: availableWidth,
+            thumbHeight: availableHeight
+        };
    },
 
     /**
         var updateLargeVideo = false;
 
         // Handle LastN/local LastN changes.
-        $('#remoteVideos>span').each(function( index, element ) {
+        BottomToolbar.getThumbs().each(function( index, element ) {
             var resourceJid = getPeerContainerResourceId(element);
 
             // We do not want to process any logic for our own(local) video