forked from cybrespace/pinafore
47 lines
1.1 KiB
JavaScript
47 lines
1.1 KiB
JavaScript
// via https://github.com/tootsuite/mastodon/blob/f59ed3a4fafab776b4eeb92f805dfe1fecc17ee3/app/javascript/mastodon/scroll.js
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const easingOutQuint = (x, t, b, c, d) =>
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c * ((t = t / d - 1) * t * t * t * t + 1) + b
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const scroll = (node, key, target) => {
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const startTime = Date.now()
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const offset = node[key]
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const gap = target - offset
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const duration = 1000
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let interrupt = false
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const step = () => {
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const elapsed = Date.now() - startTime
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const percentage = elapsed / duration
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if (interrupt) {
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return
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}
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if (percentage > 1) {
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cleanup()
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return
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}
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node[key] = easingOutQuint(0, elapsed, offset, gap, duration)
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requestAnimationFrame(step)
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}
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const cancel = () => {
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interrupt = true
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cleanup()
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}
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const cleanup = () => {
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node.removeEventListener('wheel', cancel)
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node.removeEventListener('touchstart', cancel)
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}
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node.addEventListener('wheel', cancel, {passive: true})
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node.addEventListener('touchstart', cancel, {passive: true})
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step()
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return cancel
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}
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export const smoothScrollToTop = node => scroll(node, 'scrollTop', 0)
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