snapshot of https://github.com/excalidraw/excalidraw.git (master, 2026-09-16; blobs > 131072B omitted)

packages/excalidraw/hooks/useScrollPosition.ts

@@ -0,0 +1,33 @@
+import throttle from "lodash.throttle";
+import { useEffect } from "react";
+
+import { atom, useAtom } from "../editor-jotai";
+
+const scrollPositionAtom = atom<number>(0);
+
+export const useScrollPosition = <T extends HTMLElement>(
+  elementRef: React.RefObject<T | null>,
+) => {
+  const [scrollPosition, setScrollPosition] = useAtom(scrollPositionAtom);
+
+  useEffect(() => {
+    const { current: element } = elementRef;
+    if (!element) {
+      return;
+    }
+
+    const handleScroll = throttle(() => {
+      const { scrollTop } = element;
+      setScrollPosition(scrollTop);
+    }, 200);
+
+    element.addEventListener("scroll", handleScroll);
+
+    return () => {
+      handleScroll.cancel();
+      element.removeEventListener("scroll", handleScroll);
+    };
+  }, [elementRef, setScrollPosition]);
+
+  return scrollPosition;
+};