Multiline editor (#302)

Co-authored-by: Taylor Mullen <ntaylormullen@google.com>

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

@@ -0,0 +1,32 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useEffect, useState } from 'react';
+
+const TERMINAL_PADDING_X = 8;
+
+export function useTerminalSize(): { columns: number; rows: number } {
+  const [size, setSize] = useState({
+    columns: (process.stdout.columns || 60) - TERMINAL_PADDING_X,
+    rows: process.stdout.rows || 20,
+  });
+
+  useEffect(() => {
+    function updateSize() {
+      setSize({
+        columns: (process.stdout.columns || 60) - TERMINAL_PADDING_X,
+        rows: process.stdout.rows || 20,
+      });
+    }
+
+    process.stdout.on('resize', updateSize);
+    return () => {
+      process.stdout.off('resize', updateSize);
+    };
+  }, []);
+
+  return size;
+}