32 lines
967 B
TypeScript
32 lines
967 B
TypeScript
 
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import type { Action } from 'svelte/action';
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import { syncopatedDelay } from './tokens';
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// use:reveal={index} — révèle l'élément à l'entrée dans le viewport avec cascade gwoka.
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// L'état caché est posé en CSS uniquement sous html.has-js + prefers-reduced-motion: no-preference,
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// donc le contenu reste lisible sans JS et sans animation.
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export const reveal: Action<HTMLElement, number | undefined> = (node, index = 0) => {
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const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
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if (reduce) {
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node.classList.add('is-visible');
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return;
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}
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node.style.setProperty('--d', `${syncopatedDelay(index)}ms`);
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const io = new IntersectionObserver(
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(entries) => {
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for (const e of entries) {
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if (e.isIntersecting) {
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node.classList.add('is-visible');
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io.unobserve(node);
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}
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}
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},
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{ threshold: 0.12, rootMargin: '0px 0px -8% 0px' }
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);
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io.observe(node);
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return {
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destroy() {
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io.disconnect();
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}
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};
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};
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