util.js 2.3 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253
  1. /**
  2. * @license
  3. * Copyright 2016 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. export function createFocusTrapInstance(surfaceEl, focusTrapFactory, initialFocusEl) {
  24. return focusTrapFactory(surfaceEl, { initialFocusEl: initialFocusEl });
  25. }
  26. export function isScrollable(el) {
  27. return el ? el.scrollHeight > el.offsetHeight : false;
  28. }
  29. /**
  30. * For scrollable content, returns true if the content has not been scrolled
  31. * (that is, the scroll content is as the "top"). This is used in full-screen
  32. * dialogs, where the scroll divider is expected only to appear once the
  33. * content has been scrolled "underneath" the header bar.
  34. */
  35. export function isScrollAtTop(el) {
  36. return el ? el.scrollTop === 0 : false;
  37. }
  38. /**
  39. * For scrollable content, returns true if the content has been scrolled all the
  40. * way to the bottom. This is used in full-screen dialogs, where the footer
  41. * scroll divider is expected only to appear when the content is "cut-off" by
  42. * the footer bar.
  43. */
  44. export function isScrollAtBottom(el) {
  45. return el ? Math.ceil(el.scrollHeight - el.scrollTop) === el.clientHeight :
  46. false;
  47. }
  48. export function areTopsMisaligned(els) {
  49. var tops = new Set();
  50. [].forEach.call(els, function (el) { return tops.add(el.offsetTop); });
  51. return tops.size > 1;
  52. }
  53. //# sourceMappingURL=util.js.map