onHidden.js 1.3 KB

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  1. import { WINDOW } from '../../types.js';
  2. /*
  3. * Copyright 2020 Google LLC
  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. * https://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. */
  17. const onHidden = (cb, once) => {
  18. const onHiddenOrPageHide = (event) => {
  19. if (event.type === 'pagehide' || WINDOW.document.visibilityState === 'hidden') {
  20. cb(event);
  21. if (once) {
  22. removeEventListener('visibilitychange', onHiddenOrPageHide, true);
  23. removeEventListener('pagehide', onHiddenOrPageHide, true);
  24. }
  25. }
  26. };
  27. addEventListener('visibilitychange', onHiddenOrPageHide, true);
  28. // Some browsers have buggy implementations of visibilitychange,
  29. // so we use pagehide in addition, just to be safe.
  30. addEventListener('pagehide', onHiddenOrPageHide, true);
  31. };
  32. export { onHidden };
  33. //# sourceMappingURL=onHidden.js.map