shaka-player/lib/polyfill/input_event.js

DASH/EME video player library

/*! @license
 * Shaka Player
 * Copyright 2016 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

goog.provide('shaka.polyfill.InputEvent');

goog.require('shaka.log');
goog.require('shaka.polyfill');
goog.require('shaka.util.Platform');


/**
 * @summary A polyfill to patch 'input' event support in IE11.
 */
shaka.polyfill.InputEvent = class {
  /**
   * Install the polyfill if needed.
   */
  static install() {
    shaka.log.debug('InputEvent.install');

    // IE11 doesn't treat the 'input' event correctly.
    // https://bit.ly/2loLsuX

    if (!shaka.util.Platform.isIE()) {
      // Not IE, so don't patch anything.
      return;
    }

    // In our tests, we can end up with multiple independent "shaka" namespaces.
    // So we can't compare addEventListener with the polyfill directly.
    // Instead, store the original in a globally accessible place and check if
    // that has been used yet.
    // eslint-disable-next-line no-restricted-syntax
    if (HTMLInputElement.prototype['originalAddEventListener']) {
      // The polyfill was already installed.
      return;
    }

    shaka.log.info('Patching input event support on IE.');

    // eslint-disable-next-line no-restricted-syntax
    HTMLInputElement.prototype['originalAddEventListener'] =
        // eslint-disable-next-line no-restricted-syntax
        HTMLInputElement.prototype.addEventListener;

    // eslint-disable-next-line no-restricted-syntax
    HTMLInputElement.prototype['addEventListener'] =
        // eslint-disable-next-line no-restricted-syntax
        shaka.polyfill.InputEvent.addEventListener_;
  }

  /**
   * Add an event listener to this object and translate the event types to those
   * that work on IE11.
   *
   * @param {string} type
   * @param {EventListener|function(!Event):(boolean|undefined)} listener
   * @param {(!AddEventListenerOptions|boolean)=} options
   * @this {HTMLInputElement}
   * @private
   */
  static addEventListener_(type, listener, options) {
    if (type == 'input') {
      // Based on the type of input element, translate the HTML5 'input' event
      // to one that IE11 will actually dispatch.

      switch (this.type) {
        // For range inputs, we use the 'change' event.
        case 'range':
          type = 'change';
          break;
      }
    }

    // eslint-disable-next-line no-restricted-syntax
    HTMLInputElement.prototype['originalAddEventListener'].call(
        this, type, listener, options);
  }
};


shaka.polyfill.register(shaka.polyfill.InputEvent.install);