simplify scrollTop

This commit is contained in:
Wes Bos 2020-01-27 15:36:45 -05:00
parent 80c7a41d21
commit 4c0cb690d3

View file

@ -24,22 +24,14 @@ const BackToTopLink = styled.a`
}
`;
function scrollTopMax() {
let ref;
// scrollTopMax is only on Firefox right now! https://caniuse.com/#search=scrolltopmax
return (ref = document.scrollingElement.scrollTopMax) != null
? ref
: document.scrollingElement.scrollHeight - document.documentElement.clientHeight
}
function useScrollPosition() {
const [percent, setPercent] = useState(0);
function handleScroll(event) {
console.log(document.documentElement.scrollTop);
const howFar =
document.documentElement.scrollTop /
scrollTopMax();
const scrollTop =
document.scrollingElement.scrollHeight -
document.documentElement.clientHeight;
const howFar = document.documentElement.scrollTop / scrollTop;
setPercent(howFar);
}