Files
voyage/apps/public-web/node_modules/next/dist/esm/client/use-intersection.js
PascalSchattenburg d147843c76 feat(blog): add file-based blog with dynamic slugs, MDX content and layout shell
- Introduced blog routing using Next.js App Router
- Implemented dynamic [slug] pages for blog posts
- Added MDX-based content loading via lib/posts
- Integrated shared TopBar layout with navigation
- Established clear content, lib and component separation
2026-01-22 14:14:15 +01:00

98 lines
3.1 KiB
JavaScript

import { useCallback, useEffect, useRef, useState } from 'react';
import { requestIdleCallback, cancelIdleCallback } from './request-idle-callback';
const hasIntersectionObserver = typeof IntersectionObserver === 'function';
const observers = new Map();
const idList = [];
function createObserver(options) {
const id = {
root: options.root || null,
margin: options.rootMargin || ''
};
const existing = idList.find((obj)=>obj.root === id.root && obj.margin === id.margin);
let instance;
if (existing) {
instance = observers.get(existing);
if (instance) {
return instance;
}
}
const elements = new Map();
const observer = new IntersectionObserver((entries)=>{
entries.forEach((entry)=>{
const callback = elements.get(entry.target);
const isVisible = entry.isIntersecting || entry.intersectionRatio > 0;
if (callback && isVisible) {
callback(isVisible);
}
});
}, options);
instance = {
id,
observer,
elements
};
idList.push(id);
observers.set(id, instance);
return instance;
}
function observe(element, callback, options) {
const { id, observer, elements } = createObserver(options);
elements.set(element, callback);
observer.observe(element);
return function unobserve() {
elements.delete(element);
observer.unobserve(element);
// Destroy observer when there's nothing left to watch:
if (elements.size === 0) {
observer.disconnect();
observers.delete(id);
const index = idList.findIndex((obj)=>obj.root === id.root && obj.margin === id.margin);
if (index > -1) {
idList.splice(index, 1);
}
}
};
}
export function useIntersection({ rootRef, rootMargin, disabled }) {
const isDisabled = disabled || !hasIntersectionObserver;
const [visible, setVisible] = useState(false);
const elementRef = useRef(null);
const setElement = useCallback((element)=>{
elementRef.current = element;
}, []);
useEffect(()=>{
if (hasIntersectionObserver) {
if (isDisabled || visible) return;
const element = elementRef.current;
if (element && element.tagName) {
const unobserve = observe(element, (isVisible)=>isVisible && setVisible(isVisible), {
root: rootRef?.current,
rootMargin
});
return unobserve;
}
} else {
if (!visible) {
const idleCallback = requestIdleCallback(()=>setVisible(true));
return ()=>cancelIdleCallback(idleCallback);
}
}
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [
isDisabled,
rootMargin,
rootRef,
visible,
elementRef.current
]);
const resetVisible = useCallback(()=>{
setVisible(false);
}, []);
return [
setElement,
visible,
resetVisible
];
}
//# sourceMappingURL=use-intersection.js.map