Source: lib/polyfill/video_play_promise.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.VideoPlayPromise');
  20. goog.require('shaka.log');
  21. goog.require('shaka.polyfill.register');
  24. /**
  25.  * @namespace shaka.polyfill.VideoPlayPromise
  26.  *
  27.  * @summary A polyfill to silence the play() Promise in HTML5 video.
  28.  */
  31. /**
  32.  * Install the polyfill if needed.
  33.  */
  34. shaka.polyfill.VideoPlayPromise.install = function() {
  35.   shaka.log.debug('VideoPlayPromise.install');
  37.   if (window.HTMLMediaElement) {
  38.     var originalPlay = HTMLMediaElement.prototype.play;
  39.     HTMLMediaElement.prototype.play = function() {
  40.       var p = originalPlay.apply(this, arguments);
  41.       if (p) {
  42.         // This browser is returning a Promise from play().
  43.         // If the play() call fails or is interrupted, the Promise will be
  44.         // rejected.  Some apps, however, don't listen to this Promise,
  45.         // especially since it is not available cross-browser.  If the Promise
  46.         // is rejected without anyone listening for the failure, an error will
  47.         // appear in the JS console.
  48.         // To avoid confusion over this innocuous "error", we will install a
  49.         // catch handler on the Promise.  This does not prevent the app from
  50.         // also catching failures and handling them.  It only prevents the
  51.         // console message.
  52.         p.catch(function() {});
  53.       }
  54.       return p;
  55.     };
  56.   }
  57. };
  59. shaka.polyfill.register(shaka.polyfill.VideoPlayPromise.install);