Source: lib/util/dom_utils.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  8. goog.provide('shaka.util.Dom');
  10. goog.require('goog.asserts');
  13. // TODO: revisit this when Closure Compiler supports partially-exported classes.
  14. /** @export */
  15. shaka.util.Dom = class {
  16.   /**
  17.    * Creates an element, and cast the type from Element to HTMLElement.
  18.    *
  19.    * @param {string} tagName
  20.    * @return {!HTMLElement}
  21.    */
  22.   static createHTMLElement(tagName) {
  23.     const element =
  24.       /** @type {!HTMLElement} */ (document.createElement(tagName));
  25.     return element;
  26.   }
  29.   /**
  30.    * Create a "button" element with the correct type.
  31.    *
  32.    * The compiler is very picky about the use of the "disabled" property on
  33.    * HTMLElement, since it is only defined on certain subclasses of that.  This
  34.    * method merely creates a button and casts it to the correct type.
  35.    *
  36.    * @return {!HTMLButtonElement}
  37.    */
  38.   static createButton() {
  39.     const button = document.createElement('button');
  40.     button.setAttribute('type', 'button');
  41.     return /** @type {!HTMLButtonElement} */ (button);
  42.   }
  45.   /**
  46.    * Cast a Node/Element to an HTMLElement
  47.    *
  48.    * @param {!Node|!Element} original
  49.    * @return {!HTMLElement}
  50.    */
  51.   static asHTMLElement(original) {
  52.     return /** @type {!HTMLElement}*/ (original);
  53.   }
  56.   /**
  57.    * Cast a Node/Element to an HTMLCanvasElement
  58.    *
  59.    * @param {!Node|!Element} original
  60.    * @return {!HTMLCanvasElement}
  61.    */
  62.   static asHTMLCanvasElement(original) {
  63.     return /** @type {!HTMLCanvasElement}*/ (original);
  64.   }
  67.   /**
  68.    * Cast a Node/Element to an HTMLMediaElement
  69.    *
  70.    * @param {!Node|!Element} original
  71.    * @return {!HTMLMediaElement}
  72.    */
  73.   static asHTMLMediaElement(original) {
  74.     return /** @type {!HTMLMediaElement}*/ (original);
  75.   }
  78.   /**
  79.    * Returns the element with a given class name.
  80.    * Assumes the class name to be unique for a given parent.
  81.    *
  82.    * @param {string} className
  83.    * @param {!HTMLElement} parent
  84.    * @return {!HTMLElement}
  85.    */
  86.   static getElementByClassName(className, parent) {
  87.     const elements = parent.getElementsByClassName(className);
  88.     goog.asserts.assert(elements.length == 1,
  89.         'Should only be one element with class name ' + className);
  91.     return shaka.util.Dom.asHTMLElement(elements[0]);
  92.   }
  94.   /**
  95.    * Remove all of the child nodes of an element.
  96.    * @param {!Element} element
  97.    * @export
  98.    */
  99.   static removeAllChildren(element) {
  100.     while (element.firstChild) {
  101.       element.removeChild(element.firstChild);
  102.     }
  103.   }
  104. };