24 lines
544 B
JavaScript
24 lines
544 B
JavaScript
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export const isSticky = (el, scrollY, stickyTop) => {
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const top = Math.floor(el.offsetTop - scrollY);
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if (top <= stickyTop) {
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el.classList.add('is-stuck');
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} else {
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el.classList.remove('is-stuck');
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}
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};
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export default (el) => {
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if (!el) return;
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const computedStyle = window.getComputedStyle(el);
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if (!/sticky/.test(computedStyle.position)) return;
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const stickyTop = parseInt(computedStyle.top, 10);
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document.addEventListener('scroll', () => isSticky(el, window.scrollY, stickyTop), {
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passive: true,
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});
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};
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