content/browser/resources/media/client_renderer.js - experimental/chromium/src - Git at Google

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import {$} from 'chrome://resources/js/util.m.js';
 import {millisecondsToString} from './util.js';

 /**
  * CSS classes added / removed in JS to trigger styling changes.
  * @enum {string}
  */
 const ClientRendererCss = {
   NO_PLAYERS_SELECTED: 'no-players-selected',
   NO_COMPONENTS_SELECTED: 'no-components-selected',
   SELECTABLE_BUTTON: 'selectable-button',
   DESTRUCTED_PLAYER: 'destructed-player',
 };

 function removeChildren(element) {
   while (element.hasChildNodes()) {
     element.removeChild(element.lastChild);
   }
 }

 function createSelectableButton(
     id, groupName, buttonLabel, select_cb, isDestructed) {
   // For CSS styling.
   var radioButton = document.createElement('input');
   radioButton.classList.add(ClientRendererCss.SELECTABLE_BUTTON);
   radioButton.type = 'radio';
   radioButton.id = id;
   radioButton.name = groupName;

   buttonLabel.classList.add(ClientRendererCss.SELECTABLE_BUTTON);
   if (isDestructed) {
     buttonLabel.classList.add(ClientRendererCss.DESTRUCTED_PLAYER);
   }
   buttonLabel.setAttribute('for', radioButton.id);

   var fragment = document.createDocumentFragment();
   fragment.appendChild(radioButton);
   fragment.appendChild(buttonLabel);

   // Listen to 'change' rather than 'click' to keep styling in sync with
   // button behavior.
   radioButton.addEventListener('change', function() {
     select_cb();
   });

   return fragment;
 }

 function selectSelectableButton(id) {
   var element = $(id);
   if (!element) {
     console.error('failed to select button with id: ' + id);
     return;
   }

   element.checked = true;
 }

 function downloadLog(text) {
   var file = new Blob([text], {type: 'text/plain'});
   var a = document.createElement('a');
   a.href = URL.createObjectURL(file);
   a.download = 'media-internals.txt';
   a.click();
 }

 export class ClientRenderer {
   constructor() {
     this.playerListElement = $('player-list');
     var audioTableElement = $('audio-property-table');
     if (audioTableElement) {
       this.audioPropertiesTable = audioTableElement.querySelector('tbody');
     }
     var playerTableElement = $('player-property-table');
     if (playerTableElement) {
       this.playerPropertiesTable = playerTableElement.querySelector('tbody');
     }
     var logElement = $('log');
     if (logElement) {
       this.logTable = logElement.querySelector('tbody');
     }
     this.graphElement = $('graphs');
     this.audioPropertyName = $('audio-property-name');
     this.audioFocusSessionListElement_ = $('audio-focus-session-list');
     var generalAudioInformationTableElement = $('general-audio-info-table');
     if (generalAudioInformationTableElement) {
       this.generalAudioInformationTable =
           generalAudioInformationTableElement.querySelector('tbody');
     }

     this.players = null;
     this.selectedPlayer = null;
     this.selectedAudioComponentType = null;
     this.selectedAudioComponentId = null;
     this.selectedAudioCompontentData = null;

     this.selectedPlayerLogIndex = 0;

     this.filterFunction = function() {
       return true;
     };
     this.filterText = $('filter-text');
     if (this.filterText) {
       this.filterText.onkeyup = this.onTextChange_.bind(this);
     }
     this.clipboardDialog = $('clipboard-dialog');

     this.clipboardTextarea = $('clipboard-textarea');
     if (this.clipboardTextarea) {
       this.clipboardTextarea.onblur = this.hideClipboard_.bind(this);
     }
     var clipboardButtons = document.getElementsByClassName('copy-button');
     if (clipboardButtons) {
       for (var i = 0; i < clipboardButtons.length; i++) {
         clipboardButtons[i].onclick = this.copyToClipboard_.bind(this);
       }
     }

     this.saveLogButton = $('save-log-button');
     if (this.saveLogButton) {
       this.saveLogButton.onclick = this.saveLog_.bind(this);
     }

     this.hiddenKeys = ['component_id', 'component_type', 'owner_id'];

     // Tell CSS to hide certain content prior to making selections.
     document.body.classList.add(ClientRendererCss.NO_PLAYERS_SELECTED);
     document.body.classList.add(ClientRendererCss.NO_COMPONENTS_SELECTED);
   }

   /**
    * Called to set general audio information.
    * @param audioInfo The map of information.
    */
   generalAudioInformationSet(audioInfo) {
     this.drawProperties_(audioInfo, this.generalAudioInformationTable);
   }

   /**
    * Called when an audio component is added to the collection.
    * @param componentType Integer AudioComponent enum value; must match values
    * from the AudioLogFactory::AudioComponent enum.
    * @param components The entire map of components (name -> dict).
    */
   audioComponentAdded(componentType, components) {
     this.redrawAudioComponentList_(componentType, components);

     // Redraw the component if it's currently selected.
     if (this.selectedAudioComponentType === componentType &&
         this.selectedAudioComponentId &&
         this.selectedAudioComponentId in components) {
       // TODO(chcunningham): This path is used both for adding and updating
       // the components. Split this up to have a separate update method.
       // At present, this selectAudioComponent call is key to *updating* the
       // the property table for existing audio components.
       this.selectAudioComponent_(
           componentType, this.selectedAudioComponentId,
           components[this.selectedAudioComponentId]);
     }
   }

   /**
    * Called when the list of audio focus sessions has changed.
    * @param sessions A list of media sessions that contain the current state.
    */
   audioFocusSessionUpdated(sessions) {
     removeChildren(this.audioFocusSessionListElement_);

     sessions.forEach(session => {
       this.audioFocusSessionListElement_.appendChild(
           this.createAudioFocusSessionRow_(session));
     });
   }

   /**
    * Called when an audio component is removed from the collection.
    * @param componentType Integer AudioComponent enum value; must match values
    * from the AudioLogFactory::AudioComponent enum.
    * @param components The entire map of components (name -> dict).
    */
   audioComponentRemoved(componentType, components) {
     this.redrawAudioComponentList_(componentType, components);
   }

   /**
    * Called when a player is added to the collection.
    * @param players The entire map of id -> player.
    * @param player_added The player that is added.
    */
   playerAdded(players, playerAdded) {
     this.redrawPlayerList_(players);
   }

   /**
    * Called when a player is removed from the collection.
    * @param players The entire map of id -> player.
    * @param playerRemoved The player that was removed.
    */
   playerRemoved(players, playerRemoved) {
     if (playerRemoved === this.selectedPlayer) {
       removeChildren(this.playerPropertiesTable);
       removeChildren(this.logTable);
       removeChildren(this.graphElement);
       document.body.classList.add(ClientRendererCss.NO_PLAYERS_SELECTED);
     }
     this.redrawPlayerList_(players);
   }

   /**
    * Called when a property on a player is changed.
    * @param players The entire map of id -> player.
    * @param player The player that had its property changed.
    * @param key The name of the property that was changed.
    * @param value The new value of the property.
    */
   playerUpdated(players, player, key, value) {
     if (player === this.selectedPlayer) {
       this.drawProperties_(player.properties, this.playerPropertiesTable);
       this.drawLog_();
     }
     if (key === 'event' && value === 'WEBMEDIAPLAYER_DESTROYED') {
       player.destructed = true;
     }
     if ([
           'url', 'frame_url', 'frame_title', 'audio_codec_name',
           'video_codec_name', 'width', 'height', 'event'
         ].includes(key)) {
       this.redrawPlayerList_(players);
     }
   }

   createVideoCaptureFormatTable(formats) {
     if (!formats || formats.length === 0) {
       return document.createTextNode('No formats');
     }

     var table = document.createElement('table');
     var thead = document.createElement('thead');
     var theadRow = document.createElement('tr');
     for (var key in formats[0]) {
       var th = document.createElement('th');
       th.appendChild(document.createTextNode(key));
       theadRow.appendChild(th);
     }
     thead.appendChild(theadRow);
     table.appendChild(thead);
     var tbody = document.createElement('tbody');
     for (var i = 0; i < formats.length; ++i) {
       var tr = document.createElement('tr');
       for (var key in formats[i]) {
         var td = document.createElement('td');
         td.appendChild(document.createTextNode(formats[i][key]));
         tr.appendChild(td);
       }
       tbody.appendChild(tr);
     }
     table.appendChild(tbody);
     table.classList.add('video-capture-formats-table');
     return table;
   }

   redrawVideoCaptureCapabilities(videoCaptureCapabilities, keys) {
     var copyButtonElement = $('video-capture-capabilities-copy-button');
     copyButtonElement.onclick = function() {
       this.showClipboard(JSON.stringify(videoCaptureCapabilities, null, 2));
     }.bind(this);

     var videoTableBodyElement = $('video-capture-capabilities-tbody');
     removeChildren(videoTableBodyElement);

     for (var component in videoCaptureCapabilities) {
       var tableRow = document.createElement('tr');
       var device = videoCaptureCapabilities[component];
       for (var i in keys) {
         var value = device[keys[i]];
         var tableCell = document.createElement('td');
         var cellElement;
         if ((typeof value) === (typeof[])) {
           cellElement = this.createVideoCaptureFormatTable(value);
         } else {
           cellElement = document.createTextNode(
               ((typeof value) === 'undefined') ? 'n/a' : value);
         }
         tableCell.appendChild(cellElement);
         tableRow.appendChild(tableCell);
       }
       videoTableBodyElement.appendChild(tableRow);
     }
   }

   getAudioComponentName_(componentType, id) {
     var baseName;
     switch (componentType) {
       case 0:
       case 1:
         baseName = 'Controller';
         break;
       case 2:
         baseName = 'Stream';
         break;
       default:
         baseName = 'UnknownType';
         console.error('Unrecognized component type: ' + componentType);
         break;
     }
     return baseName + ' ' + id;
   }

   getListElementForAudioComponent_(componentType) {
     var listElement;
     switch (componentType) {
       case 0:
         listElement = $('audio-input-controller-list');
         break;
       case 1:
         listElement = $('audio-output-controller-list');
         break;
       case 2:
         listElement = $('audio-output-stream-list');
         break;
       default:
         console.error('Unrecognized component type: ' + componentType);
         listElement = null;
         break;
     }
     return listElement;
   }

   redrawAudioComponentList_(componentType, components) {
     // Group name imposes rule that only one component can be selected
     // (and have its properties displayed) at a time.
     var buttonGroupName = 'audio-components';

     var listElement = this.getListElementForAudioComponent_(componentType);
     if (!listElement) {
       console.error(
           'Failed to find list element for component type: ' + componentType);
       return;
     }

     var fragment = document.createDocumentFragment();
     for (var id in components) {
       var li = document.createElement('li');
       var buttonCb = this.selectAudioComponent_.bind(
           this, componentType, id, components[id]);
       var friendlyName = this.getAudioComponentName_(componentType, id);
       var label = document.createElement('label');
       label.appendChild(document.createTextNode(friendlyName));
       li.appendChild(
           createSelectableButton(id, buttonGroupName, label, buttonCb));
       fragment.appendChild(li);
     }
     removeChildren(listElement);
     listElement.appendChild(fragment);

     if (this.selectedAudioComponentType &&
         this.selectedAudioComponentType === componentType &&
         this.selectedAudioComponentId in components) {
       // Re-select the selected component since the button was just recreated.
       selectSelectableButton(this.selectedAudioComponentId);
     }
   }

   selectAudioComponent_(componentType, componentId, componentData) {
     document.body.classList.remove(ClientRendererCss.NO_COMPONENTS_SELECTED);

     this.selectedAudioComponentType = componentType;
     this.selectedAudioComponentId = componentId;
     this.selectedAudioCompontentData = componentData;
     this.drawProperties_(componentData, this.audioPropertiesTable);

     removeChildren(this.audioPropertyName);
     this.audioPropertyName.appendChild(document.createTextNode(
         this.getAudioComponentName_(componentType, componentId)));
   }

   redrawPlayerList_(players) {
     this.players = players;

     // Group name imposes rule that only one component can be selected
     // (and have its properties displayed) at a time.
     var buttonGroupName = 'player-buttons';

     var hasPlayers = false;
     var fragment = document.createDocumentFragment();
     for (var id in players) {
       hasPlayers = true;
       var player = players[id];
       var p = player.properties;
       var label = document.createElement('label');

       var nameText = p.url || 'Player ' + player.id;
       var nameNode = document.createElement('div');
       nameNode.appendChild(document.createTextNode(nameText));
       nameNode.className = 'player-name';
       label.appendChild(nameNode);

       var frame = [];
       if (p.frame_title) {
         frame.push(p.frame_title);
       }
       if (p.frame_url) {
         frame.push(p.frame_url);
       }
       var frameText = frame.join(' - ');
       if (frameText) {
         var frameNode = document.createElement('div');
         frameNode.className = 'player-frame';
         frameNode.appendChild(document.createTextNode(frameText));
         label.appendChild(frameNode);
       }

       var desc = [];
       if (p.width && p.height) {
         desc.push(p.width + 'x' + p.height);
       }
       if (p.video_codec_name) {
         desc.push(p.video_codec_name);
       }
       if (p.video_codec_name && p.audio_codec_name) {
         desc.push('+');
       }
       if (p.audio_codec_name) {
         desc.push(p.audio_codec_name);
       }
       if (p.event) {
         desc.push('(' + p.event + ')');
       }
       var descText = desc.join(' ');
       if (descText) {
         var descNode = document.createElement('div');
         descNode.className = 'player-desc';
         descNode.appendChild(document.createTextNode(descText));
         label.appendChild(descNode);
       }

       var li = document.createElement('li');
       var buttonCb = this.selectPlayer_.bind(this, player);
       li.appendChild(createSelectableButton(
           id, buttonGroupName, label, buttonCb, player.destructed));
       fragment.appendChild(li);
     }
     removeChildren(this.playerListElement);
     this.playerListElement.appendChild(fragment);

     if (this.selectedPlayer && this.selectedPlayer.id in players) {
       // Re-select the selected player since the button was just recreated.
       selectSelectableButton(this.selectedPlayer.id);
     }

     this.saveLogButton.style.display = hasPlayers ? 'inline-block' : 'none';
   }

   selectPlayer_(player) {
     document.body.classList.remove(ClientRendererCss.NO_PLAYERS_SELECTED);

     this.selectedPlayer = player;
     this.selectedPlayerLogIndex = 0;
     this.selectedAudioComponentType = null;
     this.selectedAudioComponentId = null;
     this.selectedAudioCompontentData = null;
     this.drawProperties_(player.properties, this.playerPropertiesTable);

     removeChildren(this.logTable);
     removeChildren(this.graphElement);
     this.drawLog_();
   }

   drawProperties_(propertyMap, propertiesTable) {
     removeChildren(propertiesTable);
     var sortedKeys = Object.keys(propertyMap).sort();
     for (var i = 0; i < sortedKeys.length; ++i) {
       var key = sortedKeys[i];
       if (this.hiddenKeys.indexOf(key) >= 0) {
         continue;
       }

       var value = propertyMap[key];
       var row = propertiesTable.insertRow(-1);
       var keyCell = row.insertCell(-1);
       var valueCell = row.insertCell(-1);

       keyCell.appendChild(document.createTextNode(key));
       valueCell.appendChild(document.createTextNode(JSON.stringify(value)));
     }
   }

   appendEventToLog_(event) {
     if (this.filterFunction(event.key)) {
       var row = this.logTable.insertRow(-1);

       var timestampCell = row.insertCell(-1);
       timestampCell.classList.add('timestamp');
       timestampCell.appendChild(
           document.createTextNode(millisecondsToString(event.time)));
       row.insertCell(-1).appendChild(document.createTextNode(event.key));
       row.insertCell(-1).appendChild(
           document.createTextNode(JSON.stringify(event.value)));
     }
   }

   drawLog_() {
     var toDraw =
         this.selectedPlayer.allEvents.slice(this.selectedPlayerLogIndex);
     toDraw.forEach(this.appendEventToLog_.bind(this));
     this.selectedPlayerLogIndex = this.selectedPlayer.allEvents.length;
   }

   saveLog_() {
     var strippedPlayers = [];
     for (var id in this.players) {
       var p = this.players[id];
       strippedPlayers.push({properties: p.properties, events: p.allEvents});
     }
     downloadLog(JSON.stringify(strippedPlayers, null, 2));
   }

   showClipboard(string) {
     this.clipboardTextarea.value = string;
     this.clipboardDialog.showModal();
     this.clipboardTextarea.focus();
     this.clipboardTextarea.select();
   }

   hideClipboard_() {
     if (this.clipboardDialog.open) {
       this.clipboardDialog.close();
     }
   }

   copyToClipboard_() {
     if (!this.selectedPlayer && !this.selectedAudioCompontentData) {
       return;
     }
     var properties =
         this.selectedAudioCompontentData || this.selectedPlayer.properties;
     var stringBuffer = [];

     for (var key in properties) {
       var value = properties[key];
       stringBuffer.push(key.toString());
       stringBuffer.push(': ');
       stringBuffer.push(value.toString());
       stringBuffer.push('\n');
     }

     this.showClipboard(stringBuffer.join(''));
   }

   onTextChange_(event) {
     var text = this.filterText.value.toLowerCase();
     var parts = text.split(',')
                     .map(function(part) {
                       return part.trim();
                     })
                     .filter(function(part) {
                       return part.trim().length > 0;
                     });

     this.filterFunction = function(text) {
       text = text.toLowerCase();
       return parts.length === 0 || parts.some(function(part) {
         return text.indexOf(part) !== -1;
       });
     };

     if (this.selectedPlayer) {
       removeChildren(this.logTable);
       this.selectedPlayerLogIndex = 0;
       this.drawLog_();
     }
   }

   createAudioFocusSessionRow_(session) {
     const template = $('audio-focus-session-row');
     const span = template.content.querySelectorAll('span');
     span[0].textContent = session.name;
     span[1].textContent = session.owner;
     span[2].textContent = session.state;
     return document.importNode(template.content, true);
   }
 }
	// Copyright 2013 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import {$} from 'chrome://resources/js/util.m.js';
	import {millisecondsToString} from './util.js';

	/**
	* CSS classes added / removed in JS to trigger styling changes.
	* @enum {string}
	*/
	const ClientRendererCss = {
	NO_PLAYERS_SELECTED: 'no-players-selected',
	NO_COMPONENTS_SELECTED: 'no-components-selected',
	SELECTABLE_BUTTON: 'selectable-button',
	DESTRUCTED_PLAYER: 'destructed-player',
	};

	function removeChildren(element) {
	while (element.hasChildNodes()) {
	element.removeChild(element.lastChild);
	}
	}

	function createSelectableButton(
	id, groupName, buttonLabel, select_cb, isDestructed) {
	// For CSS styling.
	var radioButton = document.createElement('input');
	radioButton.classList.add(ClientRendererCss.SELECTABLE_BUTTON);
	radioButton.type = 'radio';
	radioButton.id = id;
	radioButton.name = groupName;

	buttonLabel.classList.add(ClientRendererCss.SELECTABLE_BUTTON);
	if (isDestructed) {
	buttonLabel.classList.add(ClientRendererCss.DESTRUCTED_PLAYER);
	}
	buttonLabel.setAttribute('for', radioButton.id);

	var fragment = document.createDocumentFragment();
	fragment.appendChild(radioButton);
	fragment.appendChild(buttonLabel);

	// Listen to 'change' rather than 'click' to keep styling in sync with
	// button behavior.
	radioButton.addEventListener('change', function() {
	select_cb();
	});

	return fragment;
	}

	function selectSelectableButton(id) {
	var element = $(id);
	if (!element) {
	console.error('failed to select button with id: ' + id);
	return;
	}

	element.checked = true;
	}

	function downloadLog(text) {
	var file = new Blob([text], {type: 'text/plain'});
	var a = document.createElement('a');
	a.href = URL.createObjectURL(file);
	a.download = 'media-internals.txt';
	a.click();
	}

	export class ClientRenderer {
	constructor() {
	this.playerListElement = $('player-list');
	var audioTableElement = $('audio-property-table');
	if (audioTableElement) {
	this.audioPropertiesTable = audioTableElement.querySelector('tbody');
	}
	var playerTableElement = $('player-property-table');
	if (playerTableElement) {
	this.playerPropertiesTable = playerTableElement.querySelector('tbody');
	}
	var logElement = $('log');
	if (logElement) {
	this.logTable = logElement.querySelector('tbody');
	}
	this.graphElement = $('graphs');
	this.audioPropertyName = $('audio-property-name');
	this.audioFocusSessionListElement_ = $('audio-focus-session-list');
	var generalAudioInformationTableElement = $('general-audio-info-table');
	if (generalAudioInformationTableElement) {
	this.generalAudioInformationTable =
	generalAudioInformationTableElement.querySelector('tbody');
	}

	this.players = null;
	this.selectedPlayer = null;
	this.selectedAudioComponentType = null;
	this.selectedAudioComponentId = null;
	this.selectedAudioCompontentData = null;

	this.selectedPlayerLogIndex = 0;

	this.filterFunction = function() {
	return true;
	};
	this.filterText = $('filter-text');
	if (this.filterText) {
	this.filterText.onkeyup = this.onTextChange_.bind(this);
	}
	this.clipboardDialog = $('clipboard-dialog');

	this.clipboardTextarea = $('clipboard-textarea');
	if (this.clipboardTextarea) {
	this.clipboardTextarea.onblur = this.hideClipboard_.bind(this);
	}
	var clipboardButtons = document.getElementsByClassName('copy-button');
	if (clipboardButtons) {
	for (var i = 0; i < clipboardButtons.length; i++) {
	clipboardButtons[i].onclick = this.copyToClipboard_.bind(this);
	}
	}

	this.saveLogButton = $('save-log-button');
	if (this.saveLogButton) {
	this.saveLogButton.onclick = this.saveLog_.bind(this);
	}

	this.hiddenKeys = ['component_id', 'component_type', 'owner_id'];

	// Tell CSS to hide certain content prior to making selections.
	document.body.classList.add(ClientRendererCss.NO_PLAYERS_SELECTED);
	document.body.classList.add(ClientRendererCss.NO_COMPONENTS_SELECTED);
	}

	/**
	* Called to set general audio information.
	* @param audioInfo The map of information.
	*/
	generalAudioInformationSet(audioInfo) {
	this.drawProperties_(audioInfo, this.generalAudioInformationTable);
	}

	/**
	* Called when an audio component is added to the collection.
	* @param componentType Integer AudioComponent enum value; must match values
	* from the AudioLogFactory::AudioComponent enum.
	* @param components The entire map of components (name -> dict).
	*/
	audioComponentAdded(componentType, components) {
	this.redrawAudioComponentList_(componentType, components);

	// Redraw the component if it's currently selected.
	if (this.selectedAudioComponentType === componentType &&
	this.selectedAudioComponentId &&
	this.selectedAudioComponentId in components) {
	// TODO(chcunningham): This path is used both for adding and updating
	// the components. Split this up to have a separate update method.
	// At present, this selectAudioComponent call is key to updating the
	// the property table for existing audio components.
	this.selectAudioComponent_(
	componentType, this.selectedAudioComponentId,
	components[this.selectedAudioComponentId]);
	}
	}

	/**
	* Called when the list of audio focus sessions has changed.
	* @param sessions A list of media sessions that contain the current state.
	*/
	audioFocusSessionUpdated(sessions) {
	removeChildren(this.audioFocusSessionListElement_);

	sessions.forEach(session => {
	this.audioFocusSessionListElement_.appendChild(
	this.createAudioFocusSessionRow_(session));
	});
	}

	/**
	* Called when an audio component is removed from the collection.
	* @param componentType Integer AudioComponent enum value; must match values
	* from the AudioLogFactory::AudioComponent enum.
	* @param components The entire map of components (name -> dict).
	*/
	audioComponentRemoved(componentType, components) {
	this.redrawAudioComponentList_(componentType, components);
	}

	/**
	* Called when a player is added to the collection.
	* @param players The entire map of id -> player.
	* @param player_added The player that is added.
	*/
	playerAdded(players, playerAdded) {
	this.redrawPlayerList_(players);
	}

	/**
	* Called when a player is removed from the collection.
	* @param players The entire map of id -> player.
	* @param playerRemoved The player that was removed.
	*/
	playerRemoved(players, playerRemoved) {
	if (playerRemoved === this.selectedPlayer) {
	removeChildren(this.playerPropertiesTable);
	removeChildren(this.logTable);
	removeChildren(this.graphElement);
	document.body.classList.add(ClientRendererCss.NO_PLAYERS_SELECTED);
	}
	this.redrawPlayerList_(players);
	}

	/**
	* Called when a property on a player is changed.
	* @param players The entire map of id -> player.
	* @param player The player that had its property changed.
	* @param key The name of the property that was changed.
	* @param value The new value of the property.
	*/
	playerUpdated(players, player, key, value) {
	if (player === this.selectedPlayer) {
	this.drawProperties_(player.properties, this.playerPropertiesTable);
	this.drawLog_();
	}
	if (key === 'event' && value === 'WEBMEDIAPLAYER_DESTROYED') {
	player.destructed = true;
	}
	if ([
	'url', 'frame_url', 'frame_title', 'audio_codec_name',
	'video_codec_name', 'width', 'height', 'event'
	].includes(key)) {
	this.redrawPlayerList_(players);
	}
	}

	createVideoCaptureFormatTable(formats) {
	if (!formats \|\| formats.length === 0) {
	return document.createTextNode('No formats');
	}

	var table = document.createElement('table');
	var thead = document.createElement('thead');
	var theadRow = document.createElement('tr');
	for (var key in formats[0]) {
	var th = document.createElement('th');
	th.appendChild(document.createTextNode(key));
	theadRow.appendChild(th);
	}
	thead.appendChild(theadRow);
	table.appendChild(thead);
	var tbody = document.createElement('tbody');
	for (var i = 0; i < formats.length; ++i) {
	var tr = document.createElement('tr');
	for (var key in formats[i]) {
	var td = document.createElement('td');
	td.appendChild(document.createTextNode(formats[i][key]));
	tr.appendChild(td);
	}
	tbody.appendChild(tr);
	}
	table.appendChild(tbody);
	table.classList.add('video-capture-formats-table');
	return table;
	}

	redrawVideoCaptureCapabilities(videoCaptureCapabilities, keys) {
	var copyButtonElement = $('video-capture-capabilities-copy-button');
	copyButtonElement.onclick = function() {
	this.showClipboard(JSON.stringify(videoCaptureCapabilities, null, 2));
	}.bind(this);

	var videoTableBodyElement = $('video-capture-capabilities-tbody');
	removeChildren(videoTableBodyElement);

	for (var component in videoCaptureCapabilities) {
	var tableRow = document.createElement('tr');
	var device = videoCaptureCapabilities[component];
	for (var i in keys) {
	var value = device[keys[i]];
	var tableCell = document.createElement('td');
	var cellElement;
	if ((typeof value) === (typeof[])) {
	cellElement = this.createVideoCaptureFormatTable(value);
	} else {
	cellElement = document.createTextNode(
	((typeof value) === 'undefined') ? 'n/a' : value);
	}
	tableCell.appendChild(cellElement);
	tableRow.appendChild(tableCell);
	}
	videoTableBodyElement.appendChild(tableRow);
	}
	}

	getAudioComponentName_(componentType, id) {
	var baseName;
	switch (componentType) {
	case 0:
	case 1:
	baseName = 'Controller';
	break;
	case 2:
	baseName = 'Stream';
	break;
	default:
	baseName = 'UnknownType';
	console.error('Unrecognized component type: ' + componentType);
	break;
	}
	return baseName + ' ' + id;
	}

	getListElementForAudioComponent_(componentType) {
	var listElement;
	switch (componentType) {
	case 0:
	listElement = $('audio-input-controller-list');
	break;
	case 1:
	listElement = $('audio-output-controller-list');
	break;
	case 2:
	listElement = $('audio-output-stream-list');
	break;
	default:
	console.error('Unrecognized component type: ' + componentType);
	listElement = null;
	break;
	}
	return listElement;
	}

	redrawAudioComponentList_(componentType, components) {
	// Group name imposes rule that only one component can be selected
	// (and have its properties displayed) at a time.
	var buttonGroupName = 'audio-components';

	var listElement = this.getListElementForAudioComponent_(componentType);
	if (!listElement) {
	console.error(
	'Failed to find list element for component type: ' + componentType);
	return;
	}

	var fragment = document.createDocumentFragment();
	for (var id in components) {
	var li = document.createElement('li');
	var buttonCb = this.selectAudioComponent_.bind(
	this, componentType, id, components[id]);
	var friendlyName = this.getAudioComponentName_(componentType, id);
	var label = document.createElement('label');
	label.appendChild(document.createTextNode(friendlyName));
	li.appendChild(
	createSelectableButton(id, buttonGroupName, label, buttonCb));
	fragment.appendChild(li);
	}
	removeChildren(listElement);
	listElement.appendChild(fragment);

	if (this.selectedAudioComponentType &&
	this.selectedAudioComponentType === componentType &&
	this.selectedAudioComponentId in components) {
	// Re-select the selected component since the button was just recreated.
	selectSelectableButton(this.selectedAudioComponentId);
	}
	}

	selectAudioComponent_(componentType, componentId, componentData) {
	document.body.classList.remove(ClientRendererCss.NO_COMPONENTS_SELECTED);

	this.selectedAudioComponentType = componentType;
	this.selectedAudioComponentId = componentId;
	this.selectedAudioCompontentData = componentData;
	this.drawProperties_(componentData, this.audioPropertiesTable);

	removeChildren(this.audioPropertyName);
	this.audioPropertyName.appendChild(document.createTextNode(
	this.getAudioComponentName_(componentType, componentId)));
	}

	redrawPlayerList_(players) {
	this.players = players;

	// Group name imposes rule that only one component can be selected
	// (and have its properties displayed) at a time.
	var buttonGroupName = 'player-buttons';

	var hasPlayers = false;
	var fragment = document.createDocumentFragment();
	for (var id in players) {
	hasPlayers = true;
	var player = players[id];
	var p = player.properties;
	var label = document.createElement('label');

	var nameText = p.url \|\| 'Player ' + player.id;
	var nameNode = document.createElement('div');
	nameNode.appendChild(document.createTextNode(nameText));
	nameNode.className = 'player-name';
	label.appendChild(nameNode);

	var frame = [];
	if (p.frame_title) {
	frame.push(p.frame_title);
	}
	if (p.frame_url) {
	frame.push(p.frame_url);
	}
	var frameText = frame.join(' - ');
	if (frameText) {
	var frameNode = document.createElement('div');
	frameNode.className = 'player-frame';
	frameNode.appendChild(document.createTextNode(frameText));
	label.appendChild(frameNode);
	}

	var desc = [];
	if (p.width && p.height) {
	desc.push(p.width + 'x' + p.height);
	}
	if (p.video_codec_name) {
	desc.push(p.video_codec_name);
	}
	if (p.video_codec_name && p.audio_codec_name) {
	desc.push('+');
	}
	if (p.audio_codec_name) {
	desc.push(p.audio_codec_name);
	}
	if (p.event) {
	desc.push('(' + p.event + ')');
	}
	var descText = desc.join(' ');
	if (descText) {
	var descNode = document.createElement('div');
	descNode.className = 'player-desc';
	descNode.appendChild(document.createTextNode(descText));
	label.appendChild(descNode);
	}

	var li = document.createElement('li');
	var buttonCb = this.selectPlayer_.bind(this, player);
	li.appendChild(createSelectableButton(
	id, buttonGroupName, label, buttonCb, player.destructed));
	fragment.appendChild(li);
	}
	removeChildren(this.playerListElement);
	this.playerListElement.appendChild(fragment);

	if (this.selectedPlayer && this.selectedPlayer.id in players) {
	// Re-select the selected player since the button was just recreated.
	selectSelectableButton(this.selectedPlayer.id);
	}

	this.saveLogButton.style.display = hasPlayers ? 'inline-block' : 'none';
	}

	selectPlayer_(player) {
	document.body.classList.remove(ClientRendererCss.NO_PLAYERS_SELECTED);

	this.selectedPlayer = player;
	this.selectedPlayerLogIndex = 0;
	this.selectedAudioComponentType = null;
	this.selectedAudioComponentId = null;
	this.selectedAudioCompontentData = null;
	this.drawProperties_(player.properties, this.playerPropertiesTable);

	removeChildren(this.logTable);
	removeChildren(this.graphElement);
	this.drawLog_();
	}

	drawProperties_(propertyMap, propertiesTable) {
	removeChildren(propertiesTable);
	var sortedKeys = Object.keys(propertyMap).sort();
	for (var i = 0; i < sortedKeys.length; ++i) {
	var key = sortedKeys[i];
	if (this.hiddenKeys.indexOf(key) >= 0) {
	continue;
	}

	var value = propertyMap[key];
	var row = propertiesTable.insertRow(-1);
	var keyCell = row.insertCell(-1);
	var valueCell = row.insertCell(-1);

	keyCell.appendChild(document.createTextNode(key));
	valueCell.appendChild(document.createTextNode(JSON.stringify(value)));
	}
	}

	appendEventToLog_(event) {
	if (this.filterFunction(event.key)) {
	var row = this.logTable.insertRow(-1);

	var timestampCell = row.insertCell(-1);
	timestampCell.classList.add('timestamp');
	timestampCell.appendChild(
	document.createTextNode(millisecondsToString(event.time)));
	row.insertCell(-1).appendChild(document.createTextNode(event.key));
	row.insertCell(-1).appendChild(
	document.createTextNode(JSON.stringify(event.value)));
	}
	}

	drawLog_() {
	var toDraw =
	this.selectedPlayer.allEvents.slice(this.selectedPlayerLogIndex);
	toDraw.forEach(this.appendEventToLog_.bind(this));
	this.selectedPlayerLogIndex = this.selectedPlayer.allEvents.length;
	}

	saveLog_() {
	var strippedPlayers = [];
	for (var id in this.players) {
	var p = this.players[id];
	strippedPlayers.push({properties: p.properties, events: p.allEvents});
	}
	downloadLog(JSON.stringify(strippedPlayers, null, 2));
	}

	showClipboard(string) {
	this.clipboardTextarea.value = string;
	this.clipboardDialog.showModal();
	this.clipboardTextarea.focus();
	this.clipboardTextarea.select();
	}

	hideClipboard_() {
	if (this.clipboardDialog.open) {
	this.clipboardDialog.close();
	}
	}

	copyToClipboard_() {
	if (!this.selectedPlayer && !this.selectedAudioCompontentData) {
	return;
	}
	var properties =
	this.selectedAudioCompontentData \|\| this.selectedPlayer.properties;
	var stringBuffer = [];

	for (var key in properties) {
	var value = properties[key];
	stringBuffer.push(key.toString());
	stringBuffer.push(': ');
	stringBuffer.push(value.toString());
	stringBuffer.push('\n');
	}

	this.showClipboard(stringBuffer.join(''));
	}

	onTextChange_(event) {
	var text = this.filterText.value.toLowerCase();
	var parts = text.split(',')
	.map(function(part) {
	return part.trim();
	})
	.filter(function(part) {
	return part.trim().length > 0;
	});

	this.filterFunction = function(text) {
	text = text.toLowerCase();
	return parts.length === 0 \|\| parts.some(function(part) {
	return text.indexOf(part) !== -1;
	});
	};

	if (this.selectedPlayer) {
	removeChildren(this.logTable);
	this.selectedPlayerLogIndex = 0;
	this.drawLog_();
	}
	}

	createAudioFocusSessionRow_(session) {
	const template = $('audio-focus-session-row');
	const span = template.content.querySelectorAll('span');
	span[0].textContent = session.name;
	span[1].textContent = session.owner;
	span[2].textContent = session.state;
	return document.importNode(template.content, true);
	}
	}