Vim mode (#3936)

packages/cli/src/ui/contexts/VimModeContext.tsx

@@ -0,0 +1,79 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useState,
+} from 'react';
+import { LoadedSettings, SettingScope } from '../../config/settings.js';
+
+export type VimMode = 'NORMAL' | 'INSERT';
+
+interface VimModeContextType {
+  vimEnabled: boolean;
+  vimMode: VimMode;
+  toggleVimEnabled: () => Promise<boolean>;
+  setVimMode: (mode: VimMode) => void;
+}
+
+const VimModeContext = createContext<VimModeContextType | undefined>(undefined);
+
+export const VimModeProvider = ({
+  children,
+  settings,
+}: {
+  children: React.ReactNode;
+  settings: LoadedSettings;
+}) => {
+  const initialVimEnabled = settings.merged.vimMode ?? false;
+  const [vimEnabled, setVimEnabled] = useState(initialVimEnabled);
+  const [vimMode, setVimMode] = useState<VimMode>(
+    initialVimEnabled ? 'NORMAL' : 'INSERT',
+  );
+
+  useEffect(() => {
+    // Initialize vimEnabled from settings on mount
+    const enabled = settings.merged.vimMode ?? false;
+    setVimEnabled(enabled);
+    // When vim mode is enabled, always start in NORMAL mode
+    if (enabled) {
+      setVimMode('NORMAL');
+    }
+  }, [settings.merged.vimMode]);
+
+  const toggleVimEnabled = useCallback(async () => {
+    const newValue = !vimEnabled;
+    setVimEnabled(newValue);
+    // When enabling vim mode, start in NORMAL mode
+    if (newValue) {
+      setVimMode('NORMAL');
+    }
+    await settings.setValue(SettingScope.User, 'vimMode', newValue);
+    return newValue;
+  }, [vimEnabled, settings]);
+
+  const value = {
+    vimEnabled,
+    vimMode,
+    toggleVimEnabled,
+    setVimMode,
+  };
+
+  return (
+    <VimModeContext.Provider value={value}>{children}</VimModeContext.Provider>
+  );
+};
+
+export const useVimMode = () => {
+  const context = useContext(VimModeContext);
+  if (context === undefined) {
+    throw new Error('useVimMode must be used within a VimModeProvider');
+  }
+  return context;
+};