ponyfill.js 3.0 KB

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  1. /**
  2. * @license
  3. * Copyright 2018 Google Inc.
  4. *
  5. * Permission is hereby granted, free of charge, to any person obtaining a copy
  6. * of this software and associated documentation files (the "Software"), to deal
  7. * in the Software without restriction, including without limitation the rights
  8. * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  9. * copies of the Software, and to permit persons to whom the Software is
  10. * furnished to do so, subject to the following conditions:
  11. *
  12. * The above copyright notice and this permission notice shall be included in
  13. * all copies or substantial portions of the Software.
  14. *
  15. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16. * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17. * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18. * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19. * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20. * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21. * THE SOFTWARE.
  22. */
  23. /**
  24. * @fileoverview A "ponyfill" is a polyfill that doesn't modify the global prototype chain.
  25. * This makes ponyfills safer than traditional polyfills, especially for libraries like MDC.
  26. */
  27. export function closest(element, selector) {
  28. if (element.closest) {
  29. return element.closest(selector);
  30. }
  31. var el = element;
  32. while (el) {
  33. if (matches(el, selector)) {
  34. return el;
  35. }
  36. el = el.parentElement;
  37. }
  38. return null;
  39. }
  40. export function matches(element, selector) {
  41. var nativeMatches = element.matches
  42. || element.webkitMatchesSelector
  43. || element.msMatchesSelector;
  44. return nativeMatches.call(element, selector);
  45. }
  46. /**
  47. * Used to compute the estimated scroll width of elements. When an element is
  48. * hidden due to display: none; being applied to a parent element, the width is
  49. * returned as 0. However, the element will have a true width once no longer
  50. * inside a display: none context. This method computes an estimated width when
  51. * the element is hidden or returns the true width when the element is visble.
  52. * @param {Element} element the element whose width to estimate
  53. */
  54. export function estimateScrollWidth(element) {
  55. // Check the offsetParent. If the element inherits display: none from any
  56. // parent, the offsetParent property will be null (see
  57. // https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/offsetParent).
  58. // This check ensures we only clone the node when necessary.
  59. var htmlEl = element;
  60. if (htmlEl.offsetParent !== null) {
  61. return htmlEl.scrollWidth;
  62. }
  63. var clone = htmlEl.cloneNode(true);
  64. clone.style.setProperty('position', 'absolute');
  65. clone.style.setProperty('transform', 'translate(-9999px, -9999px)');
  66. document.documentElement.appendChild(clone);
  67. var scrollWidth = clone.scrollWidth;
  68. document.documentElement.removeChild(clone);
  69. return scrollWidth;
  70. }
  71. //# sourceMappingURL=ponyfill.js.map