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useVirtualScrollParent() hook using useVirtual() from react-virtual
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| const html = document.documentElement | |
| const body = document.body | |
| /** | |
| Pseudo HTML element which behaves like a regular element in terms of scrolling. | |
| */ | |
| const documentElement = { | |
| set scrollLeft(x) { html.scrollLeft = x }, | |
| get scrollLeft() { return window.scrollX || window.pageXOffset }, | |
| set scrollTop(x) { html.scrollTop = x }, | |
| get scrollTop() { return window.scrollY || window.pageYOffset }, | |
| get scrollWidth() { | |
| return Math.max( | |
| body.scrollWidth, html.scrollWidth, | |
| body.offsetWidth, html.offsetWidth, | |
| body.clientWidth, html.clientWidth, | |
| ) | |
| }, | |
| get scrollHeight() { | |
| return Math.max( | |
| body.scrollHeight, html.scrollHeight, | |
| body.offsetHeight, html.offsetHeight, | |
| body.clientHeight, html.clientHeight, | |
| ) | |
| }, | |
| get clientWidth() { return html.clientWidth }, | |
| get clientHeight() { return html.clientHeight }, | |
| getBoundingClientRect() { | |
| return { | |
| x: 0, | |
| y: 0, | |
| top: 0, | |
| left: 0, | |
| width: this.clientWidth, | |
| height: this.clientHeight, | |
| } | |
| }, | |
| addEventListener(event, ...args) { | |
| const target = event === 'scroll' ? window : html | |
| return target.addEventListener(event, ...args) | |
| }, | |
| removeEventListener(event, ...args) { | |
| const target = event === 'scroll' ? window : html | |
| return target.removeEventListener(event, ...args) | |
| }, | |
| } | |
| export default documentElement |
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| import React from 'react' | |
| import { useVirtual } from 'react-virtual' | |
| import documentElement from './document-element' | |
| export default function useVirtualScrollParent(options) { | |
| const sizeKey = options.horizontal ? 'width' : 'height' | |
| const { parentRef } = options | |
| const [rowSize, setRowSize] = React.useState(options.estimateSize(0)) | |
| // Mock the API surface currently used through parentRef | |
| const mockedParentRef = React.useRef(null) | |
| React.useLayoutEffect(() => { | |
| const scrolled = parentRef.current | |
| if (!scrolled) { return } | |
| let scrollParent = findScrollParent(scrolled) | |
| if (scrollParent === document.documentElement) { | |
| scrollParent = documentElement | |
| } | |
| let originalScrollListener = null | |
| const scrollListener = (originalEvent) => { | |
| // Compensate for potential <body> offset (due to disabled scrolling for example) | |
| const bodyOffset = scrollParent === documentElement | |
| ? parseInt(document.body.style.top || '0', 10) | |
| : 0 | |
| const target = { | |
| scrollLeft: scrollParent.scrollLeft - scrolled.offsetLeft, | |
| scrollTop: scrollParent.scrollTop - scrolled.offsetTop - bodyOffset, | |
| } | |
| originalScrollListener({ target }) | |
| } | |
| mockedParentRef.current = { | |
| get scrollLeft() { | |
| return scrollParent.scrollLeft - scrolled.offsetLeft | |
| }, | |
| set scrollLeft(x) { | |
| scrollParent.scrollLeft = x + scrolled.offsetLeft | |
| }, | |
| get scrollTop() { | |
| return scrollParent.scrollTop - scrolled.offsetTop | |
| }, | |
| set scrollTop(x) { | |
| scrollParent.scrollTop = x + scrolled.offsetTop | |
| }, | |
| getBoundingClientRect: () => ({ | |
| width: scrollParent.clientWidth, | |
| height: scrollParent.clientHeight, | |
| }), | |
| addEventListener: (type, listener, ...args) => { | |
| // Only proxy 'scroll' event listeners | |
| if (type === 'scroll') { | |
| originalScrollListener = listener | |
| listener = scrollListener | |
| args = [] // has to be reset for IE11 to be able to later remove it | |
| listener() | |
| } | |
| return scrollParent.addEventListener(type, listener, ...args) | |
| }, | |
| removeEventListener: (type, listener, ...args) => { | |
| if (type === 'scroll') { | |
| listener = scrollListener | |
| args = [] | |
| } | |
| return scrollParent.removeEventListener(type, listener, ...args) | |
| } | |
| } | |
| }, [parentRef]) | |
| const rowVirtualizer = useVirtual({ | |
| ...options, | |
| parentRef: mockedParentRef, | |
| estimateSize: React.useCallback(() => rowSize, [rowSize]), | |
| }) | |
| // Calculate row size from first item only | |
| const sizedElementRef = React.useRef() | |
| const estimateSizeRef = React.useCallback(element => { | |
| sizedElementRef.current = element | |
| if (!element) { return } | |
| setRowSize(element.getBoundingClientRect()[sizeKey] + 1) | |
| }, [setRowSize, sizeKey]) | |
| // Re-calculate row size on window resize | |
| React.useLayoutEffect(() => { | |
| const onResize = () => { | |
| if (!sizedElementRef.current) { return } | |
| setRowSize(sizedElementRef.current.getBoundingClientRect()[sizeKey] + 1) | |
| } | |
| onResize() | |
| window.addEventListener('resize', onResize) | |
| return () => { window.removeEventListener('resize', onResize) } | |
| }, [sizeKey, estimateSizeRef]) | |
| return { | |
| ...rowVirtualizer, | |
| estimateSizeRef, | |
| } | |
| } | |
| function findScrollParent(node) { | |
| const scrollingElement = document.scrollingElement || document.documentElement | |
| if (!(node instanceof HTMLElement || node instanceof SVGElement)) { | |
| return scrollingElement | |
| } | |
| let style = getComputedStyle(node) | |
| if (style.position === 'fixed') { | |
| return scrollingElement | |
| } | |
| const excludeStaticParent = style.position === 'absolute' | |
| const overflowRegex = /(auto|scroll|overlay)/ | |
| let parent = node.parentElement | |
| while (parent) { | |
| style = getComputedStyle(parent) | |
| if (excludeStaticParent && style.position === 'static') { | |
| continue | |
| } | |
| if (overflowRegex.test(style.overflow + style.overflowY + style.overflowX)) { | |
| return parent === document.body ? scrollingElement : parent | |
| } | |
| parent = parent.parentElement | |
| } | |
| return scrollingElement | |
| } |
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Good catch, I've updated the code now so that it should be correct (
target=>scrollParent)