import React, { useState, useRef, useEffect } from 'react'; import classNames from 'classnames'; export default function StickyHeader({ className, stickyClassName, stickyStyle, children, enabled = true, }) { const [sticky, setSticky] = useState(false); const ref = useRef(); const top = useRef(0); useEffect(() => { const checkPosition = () => { if (ref.current) { if (!top.current) { top.current = ref.current.offsetTop + ref.current.offsetHeight; } const state = window.pageYOffset > top.current; if (sticky !== state) { setSticky(state); } } }; checkPosition(); if (enabled) { window.addEventListener('scroll', checkPosition); } return () => { window.removeEventListener('scroll', checkPosition); }; }, [sticky, enabled]); return (