feat: Ctrl+O to expand paste placeholder (#18103)

packages/cli/src/ui/hooks/useTimedMessage.ts

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState, useCallback, useRef, useEffect } from 'react';
+
+/**
+ * A hook to manage a state value that automatically resets to null after a duration.
+ * Useful for transient UI messages, hints, or warnings.
+ */
+export function useTimedMessage<T>(durationMs: number) {
+  const [message, setMessage] = useState<T | null>(null);
+  const timeoutRef = useRef<NodeJS.Timeout | null>(null);
+
+  const showMessage = useCallback(
+    (msg: T) => {
+      setMessage(msg);
+      if (timeoutRef.current) {
+        clearTimeout(timeoutRef.current);
+      }
+      timeoutRef.current = setTimeout(() => {
+        setMessage(null);
+      }, durationMs);
+    },
+    [durationMs],
+  );
+
+  useEffect(
+    () => () => {
+      if (timeoutRef.current) {
+        clearTimeout(timeoutRef.current);
+      }
+    },
+    [],
+  );
+
+  return [message, showMessage] as const;
+}