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author | crupest <crupest@outlook.com> | 2022-04-24 19:56:15 +0800 |
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committer | crupest <crupest@outlook.com> | 2022-04-24 19:56:15 +0800 |
commit | c81dfffe0076c94dc61397fd17677cb24f67cdf2 (patch) | |
tree | 8cf9811371dfb68a487bbde199c67628e12ed020 /FrontEnd/src/utilities/useReverseScrollPositionRemember.ts | |
parent | 4fdf7d1cb50c3dd8ea8e96f7fb4cf8f655152dcc (diff) | |
download | timeline-c81dfffe0076c94dc61397fd17677cb24f67cdf2.tar.gz timeline-c81dfffe0076c94dc61397fd17677cb24f67cdf2.tar.bz2 timeline-c81dfffe0076c94dc61397fd17677cb24f67cdf2.zip |
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Diffstat (limited to 'FrontEnd/src/utilities/useReverseScrollPositionRemember.ts')
-rw-r--r-- | FrontEnd/src/utilities/useReverseScrollPositionRemember.ts | 56 |
1 files changed, 0 insertions, 56 deletions
diff --git a/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts b/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts deleted file mode 100644 index 6fdd4b43..00000000 --- a/FrontEnd/src/utilities/useReverseScrollPositionRemember.ts +++ /dev/null @@ -1,56 +0,0 @@ -import React from "react"; - -let on = false; - -let rememberedReversePosition = getReverseScrollPosition(); - -export function getReverseScrollPosition(): number { - if (document.documentElement.scrollHeight <= window.innerHeight) { - return 0; - } else { - return ( - document.documentElement.scrollHeight - - document.documentElement.scrollTop - - window.innerHeight - ); - } -} - -export function scrollToReverseScrollPosition(reversePosition: number): void { - if (document.documentElement.scrollHeight <= window.innerHeight) return; - - const old = document.documentElement.style.scrollBehavior; - document.documentElement.style.scrollBehavior = "auto"; - - const newPosition = - document.documentElement.scrollHeight - - window.innerHeight - - reversePosition; - - window.scrollTo(0, newPosition); - - document.documentElement.style.scrollBehavior = old; -} - -const scrollListener = (): void => { - rememberedReversePosition = getReverseScrollPosition(); -}; - -const resizeObserver = new ResizeObserver(() => { - scrollToReverseScrollPosition(rememberedReversePosition); -}); - -export default function useReverseScrollPositionRemember(): void { - React.useEffect(() => { - if (on) return; - on = true; - window.addEventListener("scroll", scrollListener); - resizeObserver.observe(document.documentElement); - - return () => { - resizeObserver.disconnect(); - window.removeEventListener("scroll", scrollListener); - on = false; - }; - }, []); -} |