feat: start of monorepo

packages/website/src/hooks/useOnScreen.ts

@@ -0,0 +1,26 @@
+import { RefObject, useEffect, useRef, useState } from 'react';
+
+/**
+ * Thanks GuCier!
+ *
+ * https://stackoverflow.com/a/65008608/12294756
+ */
+export default function useOnScreen(ref: RefObject<HTMLElement>) {
+  const [isIntersecting, setIntersecting] = useState(false);
+  const observer = useRef<IntersectionObserver>();
+
+  useEffect(() => {
+    observer.current = new IntersectionObserver(([entry]) =>
+      setIntersecting(entry.isIntersecting),
+    );
+  }, [ref]);
+
+  useEffect(() => {
+    if (!ref.current) return;
+
+    observer.current?.observe(ref.current);
+    return () => observer.current?.disconnect();
+  }, [ref]);
+
+  return isIntersecting;
+}