diff options
Diffstat (limited to 'FrontEnd/src/app/utilities')
-rw-r--r-- | FrontEnd/src/app/utilities/useReverseScrollPositionRemember.ts | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/FrontEnd/src/app/utilities/useReverseScrollPositionRemember.ts b/FrontEnd/src/app/utilities/useReverseScrollPositionRemember.ts new file mode 100644 index 00000000..8a2bd7a0 --- /dev/null +++ b/FrontEnd/src/app/utilities/useReverseScrollPositionRemember.ts @@ -0,0 +1,33 @@ +import React from "react"; + +let on = false; + +export default function useReverseScrollPositionRemember(): void { + React.useEffect(() => { + if (on) return; + on = true; + + let scrollPosition = + document.documentElement.scrollHeight - + document.documentElement.scrollTop; + + const scrollListener = (): void => { + scrollPosition = document.documentElement.scrollHeight - window.scrollY; + }; + + window.addEventListener("scroll", scrollListener); + + const resizeObserver = new ResizeObserver(() => { + document.documentElement.scrollTop = + document.documentElement.scrollHeight - scrollPosition; + }); + + resizeObserver.observe(document.documentElement); + + return () => { + window.removeEventListener("scroll", scrollListener); + resizeObserver.disconnect(); + on = false; + }; + }, []); +} |