jaredandClaude Sonnet 4.6
3df95adc52
Creates useNearViewport hook (IntersectionObserver, 200px rootMargin, one-shot disconnect after first trigger). ImageContent and VideoContent now gate loadSrc() on nearViewport — when autoPlay is enabled, encrypted media is not decrypted until the element is within 200px of the visible area, reducing initial page load cost on long timelines. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
31 lines
843 B
TypeScript
31 lines
843 B
TypeScript
import { RefObject, useEffect, useState } from 'react';
|
|
|
|
/**
|
|
* Returns true once the observed element has come within `margin` pixels of
|
|
* the viewport. Disconnects the observer after the first intersection so there
|
|
* is no ongoing overhead.
|
|
*/
|
|
export function useNearViewport(ref: RefObject<Element | null>, margin = 200): boolean {
|
|
const [triggered, setTriggered] = useState(false);
|
|
|
|
useEffect(() => {
|
|
const el = ref.current;
|
|
if (!el || triggered) return undefined;
|
|
|
|
const observer = new IntersectionObserver(
|
|
(entries) => {
|
|
if (entries[0]?.isIntersecting) {
|
|
setTriggered(true);
|
|
observer.disconnect();
|
|
}
|
|
},
|
|
{ rootMargin: `${margin}px` },
|
|
);
|
|
|
|
observer.observe(el);
|
|
return () => observer.disconnect();
|
|
}, [ref, margin, triggered]);
|
|
|
|
return triggered;
|
|
}
|