120 lines
2.9 KiB
JavaScript
120 lines
2.9 KiB
JavaScript
import 'intersection-observer';
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import * as React from 'react';
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import useLayoutEffect from '@react-hook/passive-layout-effect';
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function useIntersectionObserver(target, options = {}) {
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const {
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root = null,
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pollInterval = null,
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useMutationObserver = false,
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rootMargin = '0px 0px 0px 0px',
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threshold = 0,
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initialIsIntersecting = false
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} = options;
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const [entry, setEntry] = React.useState(() => ({
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boundingClientRect: null,
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intersectionRatio: 0,
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intersectionRect: null,
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isIntersecting: initialIsIntersecting,
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rootBounds: null,
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target: null,
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time: 0
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}));
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const [observer, setObserver] = React.useState(() => getIntersectionObserver({
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root,
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pollInterval,
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useMutationObserver,
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rootMargin,
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threshold
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}));
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React.useEffect(() => {
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const observer = getIntersectionObserver({
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root,
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pollInterval,
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useMutationObserver,
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rootMargin,
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threshold
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});
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setObserver(observer); // eslint-disable-next-line react-hooks/exhaustive-deps
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}, [root, rootMargin, pollInterval, useMutationObserver, JSON.stringify(threshold)]);
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useLayoutEffect(() => {
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const targetEl = target && 'current' in target ? target.current : target;
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if (!observer || !targetEl) return;
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let didUnsubscribe = false;
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observer.observer.observe(targetEl);
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const callback = entries => {
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if (didUnsubscribe) return;
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for (let i = 0; i < entries.length; i++) {
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const entry = entries[i];
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if (entry.target === targetEl) {
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setEntry(entry);
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}
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}
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};
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observer.subscribe(callback);
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return () => {
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didUnsubscribe = true;
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observer.observer.unobserve(targetEl);
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observer.unsubscribe(callback);
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};
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}, [target, observer]);
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return entry;
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}
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function createIntersectionObserver({
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root = null,
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pollInterval = null,
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useMutationObserver = false,
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rootMargin = '0px 0px 0px 0px',
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threshold = 0
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}) {
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const callbacks = new Set();
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if (typeof IntersectionObserver === 'undefined') return null;
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const observer = new IntersectionObserver(entries => {
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for (const callback of callbacks) callback(entries, observer);
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}, {
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root,
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rootMargin,
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threshold
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}); // @ts-ignore
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observer.POLL_INTERVAL = pollInterval; // @ts-ignore
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observer.USE_MUTATION_OBSERVER = useMutationObserver;
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return {
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observer,
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getListeners() {
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return callbacks;
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},
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subscribe: callback => callbacks.add(callback),
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unsubscribe: callback => callbacks.delete(callback)
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};
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}
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const _intersectionObserver = /*#__PURE__*/new Map();
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function getIntersectionObserver(options) {
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const {
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root,
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...keys
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} = options;
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const key = JSON.stringify(keys);
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let base = _intersectionObserver.get(root);
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if (!base) {
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base = {};
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_intersectionObserver.set(root, base);
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}
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return !base[key] ? base[key] = createIntersectionObserver(options) : base[key];
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}
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export default useIntersectionObserver; |