Mawoka
31 lines
841 B
JavaScript
31 lines
841 B
JavaScript
/*
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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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// Stolen from https://svelte.dev/repl/c6a402704224403f96a3db56c2f48dfc?version=3.55.0
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let intersectionObserver;
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function ensureIntersectionObserver() {
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if (intersectionObserver) return;
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intersectionObserver = new IntersectionObserver((entries) => {
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entries.forEach((entry) => {
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const eventName = entry.isIntersecting ? 'enterViewport' : 'exitViewport';
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entry.target.dispatchEvent(new CustomEvent(eventName));
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});
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});
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}
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export default function viewport(element) {
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ensureIntersectionObserver();
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intersectionObserver.observe(element);
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return {
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destroy() {
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intersectionObserver.unobserve(element);
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}
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};
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}
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