53 lines
1.6 KiB
TypeScript
53 lines
1.6 KiB
TypeScript
/*
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* Copyright (C) Contributors to the Suwayomi project
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/.
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*/
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import type { RefObject } from 'react';
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import { useLayoutEffect, useState } from 'react';
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export const useIntersectionObserver = (
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ref: RefObject<HTMLElement | null> | HTMLElement | undefined | null,
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callback: IntersectionObserverCallback,
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{
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ignoreInitialObserve = false,
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root,
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rootMargin,
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threshold,
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}: IntersectionObserverInit & { ignoreInitialObserve?: boolean } = {},
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): (() => void) => {
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const [disconnect, setDisconnect] = useState<() => void>(() => {});
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useLayoutEffect(() => {
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const element = ref instanceof HTMLElement ? ref : ref?.current;
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if (!element) {
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return () => {};
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}
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// gets immediately observed once on initial render
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let isInitialObserve = true;
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const intersectionObserver = new IntersectionObserver(
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(...args) => {
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if (ignoreInitialObserve && isInitialObserve) {
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isInitialObserve = false;
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return;
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}
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callback(...args);
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},
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{ root, rootMargin, threshold },
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);
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intersectionObserver.observe(element);
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setDisconnect(() => () => intersectionObserver.disconnect());
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return () => intersectionObserver.disconnect();
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}, [ref, callback, ignoreInitialObserve, root, rootMargin, threshold]);
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return disconnect;
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};
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