Source: lib/polyfill/patchedmediakeys_nop.js

  1. /**
  2.  * @license
  3.  * Copyright 2016 Google Inc.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  18. goog.provide('shaka.polyfill.PatchedMediaKeysNop');
  20. goog.require('goog.asserts');
  21. goog.require('shaka.log');
  22. goog.require('shaka.polyfill.register');
  25. /**
  26.  * @namespace shaka.polyfill.PatchedMediaKeysNop
  27.  *
  28.  * @summary A polyfill to stub out
  29.  * {@link https://bit.ly/EmeMar15 EME draft 12 March 2015} on browsers without
  30.  * EME.
  31.  * All methods will fail.
  32.  */
  35. /**
  36.  * Installs the polyfill if needed.
  37.  */
  38. shaka.polyfill.PatchedMediaKeysNop.install = function() {
  39.   if (!window.HTMLVideoElement ||
  40.       (navigator.requestMediaKeySystemAccess &&
  41.        MediaKeySystemAccess.prototype.getConfiguration)) {
  42.     return;
  43.   }
  44.   shaka.log.info('EME not available.');
  46.   // Alias.
  47.   const PatchedMediaKeysNop = shaka.polyfill.PatchedMediaKeysNop;
  49.   // Install patches.
  50.   navigator.requestMediaKeySystemAccess =
  51.       PatchedMediaKeysNop.requestMediaKeySystemAccess;
  52.   // Delete mediaKeys to work around strict mode compatibility issues.
  53.   delete HTMLMediaElement.prototype['mediaKeys'];
  54.   // Work around read-only declaration for mediaKeys by using a string.
  55.   HTMLMediaElement.prototype['mediaKeys'] = null;
  56.   HTMLMediaElement.prototype.setMediaKeys = PatchedMediaKeysNop.setMediaKeys;
  57.   // These are not usable, but allow Player.isBrowserSupported to pass.
  58.   window.MediaKeys = PatchedMediaKeysNop.MediaKeys;
  59.   window.MediaKeySystemAccess = PatchedMediaKeysNop.MediaKeySystemAccess;
  60. };
  63. /**
  64.  * An implementation of navigator.requestMediaKeySystemAccess.
  65.  * Retrieves a MediaKeySystemAccess object.
  66.  *
  67.  * @this {!Navigator}
  68.  * @param {string} keySystem
  69.  * @param {!Array.<!MediaKeySystemConfiguration>} supportedConfigurations
  70.  * @return {!Promise.<!MediaKeySystemAccess>}
  71.  */
  72. shaka.polyfill.PatchedMediaKeysNop.requestMediaKeySystemAccess =
  73.     function(keySystem, supportedConfigurations) {
  74.   shaka.log.debug('PatchedMediaKeysNop.requestMediaKeySystemAccess');
  75.   goog.asserts.assert(this == navigator,
  76.                       'bad "this" for requestMediaKeySystemAccess');
  79.   return Promise.reject(new Error(
  80.       'The key system specified is not supported.'));
  81. };
  84. /**
  85.  * An implementation of HTMLMediaElement.prototype.setMediaKeys.
  86.  * Attaches a MediaKeys object to the media element.
  87.  *
  88.  * @this {!HTMLMediaElement}
  89.  * @param {MediaKeys} mediaKeys
  90.  * @return {!Promise}
  91.  */
  92. shaka.polyfill.PatchedMediaKeysNop.setMediaKeys = function(mediaKeys) {
  93.   shaka.log.debug('PatchedMediaKeysNop.setMediaKeys');
  94.   goog.asserts.assert(this instanceof HTMLMediaElement,
  95.                       'bad "this" for setMediaKeys');
  97.   if (mediaKeys == null) {
  98.     return Promise.resolve();
  99.   }
  101.   return Promise.reject(new Error('MediaKeys not supported.'));
  102. };
  105. /**
  106.  * An unusable constructor for MediaKeys.
  107.  * @constructor
  108.  * @struct
  109.  * @implements {MediaKeys}
  110.  */
  111. shaka.polyfill.PatchedMediaKeysNop.MediaKeys = function() {
  112.   throw new TypeError('Illegal constructor.');
  113. };
  116. /** @override */
  117. shaka.polyfill.PatchedMediaKeysNop.MediaKeys.prototype.createSession =
  118.     function() {};
  121. /** @override */
  122. shaka.polyfill.PatchedMediaKeysNop.MediaKeys.prototype.setServerCertificate =
  123.     function() {};
  126. /**
  127.  * An unusable constructor for MediaKeySystemAccess.
  128.  * @constructor
  129.  * @struct
  130.  * @implements {MediaKeySystemAccess}
  131.  */
  132. shaka.polyfill.PatchedMediaKeysNop.MediaKeySystemAccess = function() {
  133.   throw new TypeError('Illegal constructor.');
  134. };
  137. /** @override */
  138. shaka.polyfill.PatchedMediaKeysNop.MediaKeySystemAccess.prototype.
  139.     getConfiguration = function() {};
  142. /** @override */
  143. shaka.polyfill.PatchedMediaKeysNop.MediaKeySystemAccess.prototype.
  144.     createMediaKeys = function() {};
  147. /** @override */
  148. shaka.polyfill.PatchedMediaKeysNop.MediaKeySystemAccess.prototype.
  149.     keySystem;
  152. // A low priority ensures this is the last and acts as a fallback.
  153. shaka.polyfill.register(shaka.polyfill.PatchedMediaKeysNop.install, -10);