Files
mkdocs-material/src/assets/javascripts/components/navigation/layer/watch/index.ts
2020-03-03 18:19:33 +01:00

79 lines
2.7 KiB
TypeScript

/*
* 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 { findLast } from "ramda"
import { Observable, fromEvent, merge } from "rxjs"
import { map, scan } from "rxjs/operators"
import {
getElement,
getElementOrThrow
} from "observables"
import { NavigationLayer } from "../_"
/* ----------------------------------------------------------------------------
* Functions
* ------------------------------------------------------------------------- */
/**
* Watch navigation layer
*
* On iOS we want to add `-webkit-overflow-scrolling: touch` for the menus
* contained in the drawer, but as the navigational layers are nested, we can
* only add it to the topmost layer or extremely weird cropping will occur.
* This implementation keeps track of the previous and current layer.
*
* @param els - Navigation elements
*
* @return Navigation layer observable
*/
export function watchNavigationLayer(
els: HTMLElement[]
): Observable<NavigationLayer> {
const table = new Map<HTMLInputElement, HTMLElement>()
for (const el of els) {
const label = getElement<HTMLLabelElement>("label", el)
if (typeof label !== "undefined") {
const input = getElementOrThrow<HTMLInputElement>(`#${label.htmlFor}`)
table.set(input, el)
}
}
/* Determine topmost layer */
const layer$ = merge(...[...table.keys()].map(input => (
fromEvent(input, "change")
)))
.pipe(
map(() => getElementOrThrow(".md-nav__list", table.get(
findLast(({ checked }) => checked, [...table.keys()])!
)))
)
/* Return previous and next layer */
return layer$
.pipe(
map(next => ({ next })),
scan(({ next: prev }, { next }) => ({ prev, next }))
)
}