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-rw-r--r--FrontEnd/src/app/utilities/useReverseScrollPositionRemember.ts33
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;
+ };
+ }, []);
+}