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Diffstat (limited to 'vnext/src/components/Header.js')
-rw-r--r-- | vnext/src/components/Header.js | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/vnext/src/components/Header.js b/vnext/src/components/Header.js deleted file mode 100644 index 48f89360..00000000 --- a/vnext/src/components/Header.js +++ /dev/null @@ -1,69 +0,0 @@ -import React, { useEffect, useCallback, useRef } from 'react'; -import ReactDOM from 'react-dom'; -import PropTypes from 'prop-types'; - -const elClassHidden = 'header--hidden'; - -const header = document.getElementById('header'); -header.removeChild(document.getElementById('header_wrapper')); - -export default function Header({ children }) { - let dHeight = useRef(0); - let wHeight = useRef(0); - let wScrollCurrent = useRef(0); - let wScrollBefore = useRef(0); - let wScrollDiff = useRef(0); - - useEffect(() => { - window.addEventListener('scroll', () => (!window.requestAnimationFrame) - ? throttle(250, updateHeader) - : window.requestAnimationFrame(updateHeader), false); - }, [updateHeader]); - let throttle = (delay, fn) => { - var last, deferTimer; - return function () { - var context = this, args = arguments, now = +new Date; - if (last && now < last + delay) { - clearTimeout(deferTimer); - deferTimer = setTimeout( - function () { - last = now; - fn.apply(context, args); - }, - delay); - } else { - last = now; - fn.apply(context, args); - } - }; - }; - let updateHeader = useCallback(() => { - dHeight.current = document.body.offsetHeight; - wHeight.current = window.innerHeight; - wScrollCurrent.current = window.pageYOffset; - wScrollDiff.current = wScrollBefore.current - wScrollCurrent.current; - - if (wScrollCurrent.current <= 0) { - // scrolled to the very top; element sticks to the top - header.classList.remove(elClassHidden); - } else if (wScrollDiff > 0 && header.classList.contains(elClassHidden)) { - // scrolled up; element slides in - header.classList.remove(elClassHidden); - } else if (wScrollDiff.current < 0) { - // scrolled down - if (wScrollCurrent.current + wHeight.current >= dHeight.current && header.classList.contains(elClassHidden)) { - // scrolled to the very bottom; element slides in - header.classList.remove(elClassHidden); - } else { - // scrolled down; element slides out - header.classList.add(elClassHidden); - } - } - wScrollBefore.current = wScrollCurrent.current; - }, []); - return ReactDOM.createPortal(children, header); -} - -Header.propTypes = { - children: PropTypes.node -}; |