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| /* | |
| * Copyright (c) 2016-2020 Martin Donath <martin.donath@squidfunk.com> | |
| * | |
| * Permission is hereby granted, free of charge, to any person obtaining a copy | |
| * of this software and associated documentation files (the "Software"), to | |
| * deal in the Software without restriction, including without limitation the | |
| * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or | |
| * sell copies of the Software, and to permit persons to whom the Software is | |
| * furnished to do so, subject to the following conditions: | |
| * | |
| * The above copyright notice and this permission notice shall be included in | |
| * all copies or substantial portions of the Software. | |
| * | |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE | |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
| * IN THE SOFTWARE. | |
| */ | |
| import { NEVER, Observable, fromEvent, iif, merge } from "rxjs" | |
| import { map, mapTo, shareReplay, switchMap } from "rxjs/operators" | |
| import { getElements } from "browser" | |
| /* ---------------------------------------------------------------------------- | |
| * Helper types | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Patch options | |
| */ | |
| interface PatchOptions { | |
| document$: Observable<Document> /* Document observable */ | |
| } | |
| /* ---------------------------------------------------------------------------- | |
| * Helper functions | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Check whether the given device is an Apple device | |
| * | |
| * @return Test result | |
| */ | |
| function isAppleDevice(): boolean { | |
| return /(iPad|iPhone|iPod)/.test(navigator.userAgent) | |
| } | |
| /* ---------------------------------------------------------------------------- | |
| * Functions | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Patch all elements with `data-md-scrollfix` attributes | |
| * | |
| * This is a year-old patch which ensures that overflow scrolling works at the | |
| * top and bottom of containers on iOS by ensuring a `1px` scroll offset upon | |
| * the start of a touch event. | |
| * | |
| * @see https://bit.ly/2SCtAOO - Original source | |
| * | |
| * @param options - Options | |
| */ | |
| export function patchScrollfix( | |
| { document$ }: PatchOptions | |
| ): void { | |
| const els$ = document$ | |
| .pipe( | |
| map(() => getElements("[data-md-scrollfix]")), | |
| shareReplay({ bufferSize: 1, refCount: true }) | |
| ) | |
| /* Remove marker attribute, so we'll only add the fix once */ | |
| els$.subscribe(els => { | |
| for (const el of els) | |
| el.removeAttribute("data-md-scrollfix") | |
| }) | |
| /* Patch overflow scrolling on touch start */ | |
| iif(isAppleDevice, els$, NEVER) | |
| .pipe( | |
| switchMap(els => merge(...els.map(el => ( | |
| fromEvent(el, "touchstart") | |
| .pipe( | |
| mapTo(el) | |
| ) | |
| )))) | |
| ) | |
| .subscribe(el => { | |
| const top = el.scrollTop | |
| /* We're at the top of the container */ | |
| if (top === 0) { | |
| el.scrollTop = 1 | |
| /* We're at the bottom of the container */ | |
| } else if (top + el.offsetHeight === el.scrollHeight) { | |
| el.scrollTop = top - 1 | |
| } | |
| }) | |
| } |