Save settings to ~/.gemini/settings.json and optionally /your/workspace/.gemini/settings.json (#237)

packages/cli/src/config/settings.ts

@@ -0,0 +1,132 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as fs from 'fs';
+import * as path from 'path';
+import { homedir } from 'os';
+import { Config } from '@gemini-code/server';
+
+const SETTINGS_DIRECTORY_NAME = '.gemini';
+const USER_SETTINGS_DIR = path.join(homedir(), SETTINGS_DIRECTORY_NAME);
+const USER_SETTINGS_PATH = path.join(USER_SETTINGS_DIR, 'settings.json');
+
+export enum SettingScope {
+  User = 'User',
+  Workspace = 'Workspace',
+}
+
+export interface Settings {
+  theme?: string;
+  // Add other settings here.
+}
+
+export interface SettingsFile {
+  settings: Settings;
+  path: string;
+}
+export class LoadedSettings {
+  constructor(user: SettingsFile, workspace: SettingsFile) {
+    this.user = user;
+    this.workspace = workspace;
+    this.merged = this.computeMergedSettings();
+  }
+
+  readonly user: SettingsFile;
+  readonly workspace: SettingsFile;
+
+  private merged: Settings;
+
+  getMerged(): Settings {
+    return this.merged;
+  }
+
+  private computeMergedSettings(): Settings {
+    return {
+      ...this.user.settings,
+      ...this.workspace.settings,
+    };
+  }
+
+  forScope(scope: SettingScope): SettingsFile {
+    switch (scope) {
+      case SettingScope.User:
+        return this.user;
+      case SettingScope.Workspace:
+        return this.workspace;
+      default:
+        throw new Error(`Invalid scope: ${scope}`);
+    }
+  }
+
+  setValue(
+    scope: SettingScope,
+    key: keyof Settings,
+    value: string | undefined,
+  ): void {
+    const settingsFile = this.forScope(scope);
+    settingsFile.settings[key] = value;
+    this.merged = this.computeMergedSettings();
+    saveSettings(settingsFile);
+  }
+}
+
+/**
+ * Loads settings from user and project configuration files.
+ * Project settings override user settings.
+ */
+export function loadSettings(config: Config): LoadedSettings {
+  let userSettings: Settings = {};
+  let workspaceSettings = {};
+
+  // Load user settings
+  try {
+    if (fs.existsSync(USER_SETTINGS_PATH)) {
+      const userContent = fs.readFileSync(USER_SETTINGS_PATH, 'utf-8');
+      userSettings = JSON.parse(userContent);
+    }
+  } catch (error) {
+    console.error('Error reading user settings file:', error);
+  }
+
+  const workspaceSettingsPath = path.join(
+    config.getTargetDir(),
+    SETTINGS_DIRECTORY_NAME,
+    'settings.json',
+  );
+
+  // Load workspace settings
+  try {
+    if (fs.existsSync(workspaceSettingsPath)) {
+      const projectContent = fs.readFileSync(workspaceSettingsPath, 'utf-8');
+      workspaceSettings = JSON.parse(projectContent);
+    }
+  } catch (error) {
+    console.error('Error reading workspace settings file:', error);
+  }
+
+  return new LoadedSettings(
+    { path: USER_SETTINGS_PATH, settings: userSettings },
+    { path: workspaceSettingsPath, settings: workspaceSettings },
+  );
+}
+
+export function saveSettings(settingsFile: SettingsFile): void {
+  try {
+    // Ensure the directory exists
+    const dirPath = path.dirname(settingsFile.path);
+    if (!fs.existsSync(dirPath)) {
+      fs.mkdirSync(dirPath, { recursive: true });
+    }
+
+    fs.writeFileSync(
+      settingsFile.path,
+      JSON.stringify(settingsFile.settings, null, 2),
+      'utf-8',
+    );
+  } catch (error) {
+    console.error('Error saving user settings file:', error);
+  }
+}

packages/cli/src/gemini.ts

@@ -14,12 +14,20 @@ import { readPackageUp } from 'read-package-up';
 import { fileURLToPath } from 'node:url';
 import { dirname } from 'node:path';
 import { sandbox_command, start_sandbox } from './utils/sandbox.js';
+import { loadSettings } from './config/settings.js';
+import { themeManager } from './ui/themes/theme-manager.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
 
 async function main() {
   const config = await loadCliConfig();
+  const settings = loadSettings(config);
+  const theme = settings.getMerged().theme;
+  if (theme) {
+    themeManager.setActiveTheme(theme);
+  }
+
   let input = config.getQuestion();
 
   // hop into sandbox if we are outside and sandboxing is enabled
@@ -41,6 +49,7 @@ async function main() {
     render(
       React.createElement(App, {
         config,
+        settings,
         cliVersion,
       }),
     );

packages/cli/src/ui/App.tsx

@@ -20,6 +20,7 @@ import { useStartupWarnings } from './hooks/useAppEffects.js';
 import { shortenPath, type Config } from '@gemini-code/server';
 import { Colors } from './colors.js';
 import { Intro } from './components/Intro.js';
+import { LoadedSettings } from '../config/settings.js';
 import { Tips } from './components/Tips.js';
 import { ConsoleOutput } from './components/ConsolePatcher.js';
 import { HistoryItemDisplay } from './components/HistoryItemDisplay.js';
@@ -29,10 +30,11 @@ import { isAtCommand } from './utils/commandUtils.js';
 
 interface AppProps {
   config: Config;
+  settings: LoadedSettings;
   cliVersion: string;
 }
 
-export const App = ({ config, cliVersion }: AppProps) => {
+export const App = ({ config, settings, cliVersion }: AppProps) => {
   const [history, setHistory] = useState<HistoryItem[]>([]);
   const [startupWarnings, setStartupWarnings] = useState<string[]>([]);
   const {
@@ -40,7 +42,7 @@ export const App = ({ config, cliVersion }: AppProps) => {
     openThemeDialog,
     handleThemeSelect,
     handleThemeHighlight,
-  } = useThemeCommand();
+  } = useThemeCommand(settings);
 
   const {
     streamingState,
@@ -176,6 +178,7 @@ export const App = ({ config, cliVersion }: AppProps) => {
         <ThemeDialog
           onSelect={handleThemeSelect}
           onHighlight={handleThemeHighlight}
+          settings={settings}
         />
       ) : (
         <>

packages/cli/src/ui/components/ThemeDialog.tsx

@@ -4,33 +4,87 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import React from 'react';
-import { Box, Text } from 'ink';
+import React, { useState } from 'react';
+import { Box, Text, useInput } from 'ink';
 import { Colors } from '../colors.js';
-import { themeManager } from '../themes/theme-manager.js';
+import { themeManager, DEFAULT_THEME } from '../themes/theme-manager.js';
 import { RadioButtonSelect } from './shared/RadioButtonSelect.js';
 import { DiffRenderer } from './messages/DiffRenderer.js';
 import { colorizeCode } from '../utils/CodeColorizer.js';
+import { LoadedSettings, SettingScope } from '../../config/settings.js';
 
 interface ThemeDialogProps {
   /** Callback function when a theme is selected */
-  onSelect: (themeName: string) => void;
+  onSelect: (themeName: string | undefined, scope: SettingScope) => void;
 
   /** Callback function when a theme is highlighted */
-  onHighlight: (themeName: string) => void;
+  onHighlight: (themeName: string | undefined) => void;
+  /** The settings object */
+  settings: LoadedSettings;
 }
 
 export function ThemeDialog({
   onSelect,
   onHighlight,
+  settings,
 }: ThemeDialogProps): React.JSX.Element {
+  const [selectedScope, setSelectedScope] = useState<SettingScope>(
+    SettingScope.User,
+  );
+
   const themeItems = themeManager.getAvailableThemes().map((theme) => ({
     label: theme.active ? `${theme.name} (Active)` : theme.name,
     value: theme.name,
   }));
-  const initialIndex = themeItems.findIndex(
-    (item) => item.value === themeManager.getActiveTheme().name,
+  const [selectInputKey, setSelectInputKey] = useState(Date.now());
+
+  const initialThemeIndex = themeItems.findIndex(
+    (item) =>
+      item.value ===
+      (settings.forScope(selectedScope).settings.theme || DEFAULT_THEME.name),
   );
+
+  const scopeItems = [
+    { label: 'User Settings', value: SettingScope.User },
+    { label: 'Workspace Settings', value: SettingScope.Workspace },
+  ];
+
+  const handleThemeSelect = (themeName: string) => {
+    onSelect(themeName, selectedScope);
+  };
+
+  const handleScopeHighlight = (scope: SettingScope) => {
+    setSelectedScope(scope);
+    setSelectInputKey(Date.now());
+  };
+
+  const handleScopeSelect = (scope: SettingScope) => {
+    handleScopeHighlight(scope);
+    setFocusedSection('theme'); // Reset focus to theme section
+  };
+
+  const [focusedSection, setFocusedSection] = useState<'theme' | 'scope'>(
+    'theme',
+  );
+
+  useInput((input, key) => {
+    if (key.tab) {
+      setFocusedSection((prev) => (prev === 'theme' ? 'scope' : 'theme'));
+    }
+  });
+
+  let otherScopeModifiedMessage = '';
+  const otherScope =
+    selectedScope === SettingScope.User
+      ? SettingScope.Workspace
+      : SettingScope.User;
+  if (settings.forScope(otherScope).settings.theme !== undefined) {
+    otherScopeModifiedMessage =
+      settings.forScope(selectedScope).settings.theme !== undefined
+        ? `(Also modified in ${otherScope})`
+        : `(Modified in ${otherScope})`;
+  }
+
   return (
     <Box
       borderStyle="round"
@@ -39,18 +93,36 @@ export function ThemeDialog({
       padding={1}
       width="50%"
     >
-      <Box marginBottom={1}>
-        <Text bold>Select Theme</Text>
-      </Box>
+      <Text bold={focusedSection === 'theme'}>
+        {focusedSection === 'theme' ? '> ' : '  '}Select Theme{' '}
+        <Text color={Colors.SubtleComment}>{otherScopeModifiedMessage}</Text>
+      </Text>
+
       <RadioButtonSelect
+        key={selectInputKey}
         items={themeItems}
-        initialIndex={initialIndex}
-        onSelect={onSelect}
+        initialIndex={initialThemeIndex}
+        onSelect={handleThemeSelect} // Use the wrapper handler
         onHighlight={onHighlight}
+        isFocused={focusedSection === 'theme'}
       />
+      {/* Scope Selection */}
+      <Box marginTop={1} flexDirection="column">
+        <Text bold={focusedSection === 'scope'}>
+          {focusedSection === 'scope' ? '> ' : '  '}Apply To
+        </Text>
+        <RadioButtonSelect
+          items={scopeItems}
+          initialIndex={0} // Default to User Settings
+          onSelect={handleScopeSelect}
+          onHighlight={handleScopeHighlight}
+          isFocused={focusedSection === 'scope'}
+        />
+      </Box>
+
       <Box marginTop={1}>
         <Text color={Colors.SubtleComment}>
-          (Use ↑/↓ arrows and Enter to select)
+          (Use ↑/↓ arrows and Enter to select, Tab to change focus)
         </Text>
       </Box>
 

packages/cli/src/ui/components/shared/RadioButtonSelect.tsx

@@ -37,6 +37,9 @@ export interface RadioButtonSelectProps<T> {
 
   /** Function called when an item is highlighted. Receives the `value` of the selected item. */
   onHighlight?: (value: T) => void;
+
+  /** Whether this select input is currently focused and should respond to input. */
+  isFocused?: boolean;
 }
 
 /**
@@ -77,6 +80,7 @@ export function RadioButtonSelect<T>({
   initialIndex,
   onSelect,
   onHighlight,
+  isFocused,
 }: RadioButtonSelectProps<T>): React.JSX.Element {
   const handleSelect = (item: RadioSelectItem<T>) => {
     onSelect(item.value);
@@ -95,6 +99,7 @@ export function RadioButtonSelect<T>({
       initialIndex={initialIndex}
       onSelect={handleSelect}
       onHighlight={handleHighlight}
+      isFocused={isFocused}
     />
   );
 }

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

@@ -6,23 +6,36 @@
 
 import { useState, useCallback } from 'react';
 import { themeManager } from '../themes/theme-manager.js';
+import { LoadedSettings, SettingScope } from '../../config/settings.js'; // Import LoadedSettings, AppSettings, MergedSetting
 
 interface UseThemeCommandReturn {
   isThemeDialogOpen: boolean;
   openThemeDialog: () => void;
-  handleThemeSelect: (themeName: string) => void;
-  handleThemeHighlight: (themeName: string) => void;
+  handleThemeSelect: (
+    themeName: string | undefined,
+    scope: SettingScope,
+  ) => void; // Added scope
+  handleThemeHighlight: (themeName: string | undefined) => void;
 }
 
-export const useThemeCommand = (): UseThemeCommandReturn => {
-  const [isThemeDialogOpen, setIsThemeDialogOpen] = useState(false);
+export const useThemeCommand = (
+  loadedSettings: LoadedSettings, // Changed parameter
+): UseThemeCommandReturn => {
+  // Determine the effective theme
+  const effectiveTheme = loadedSettings.getMerged().theme;
+
+  // Initial state: Open dialog if no theme is set in either user or workspace settings
+  const [isThemeDialogOpen, setIsThemeDialogOpen] = useState(
+    effectiveTheme === undefined,
+  );
+  // TODO: refactor how theme's are accessed to avoid requiring a forced render.
   const [, setForceRender] = useState(0);
 
   const openThemeDialog = useCallback(() => {
     setIsThemeDialogOpen(true);
   }, []);
 
-  function applyTheme(themeName: string) {
+  function applyTheme(themeName: string | undefined) {
     try {
       themeManager.setActiveTheme(themeName);
       setForceRender((v) => v + 1); // Trigger potential re-render
@@ -31,17 +44,25 @@ export const useThemeCommand = (): UseThemeCommandReturn => {
     }
   }
 
-  const handleThemeHighlight = useCallback((themeName: string) => {
+  const handleThemeHighlight = useCallback(
+    (themeName: string | undefined) => {
       applyTheme(themeName);
-  }, []);
+    },
+    [applyTheme],
+  ); // Added applyTheme to dependencies
 
-  const handleThemeSelect = useCallback((themeName: string) => {
+  const handleThemeSelect = useCallback(
+    (themeName: string | undefined, scope: SettingScope) => {
+      // Added scope parameter
       try {
-      applyTheme(themeName);
+        loadedSettings.setValue(scope, 'theme', themeName); // Update the merged settings
+        applyTheme(loadedSettings.getMerged().theme); // Apply the current theme
       } finally {
         setIsThemeDialogOpen(false); // Close the dialog
       }
-  }, []);
+    },
+    [applyTheme], // Added applyTheme to dependencies
+  );
 
   return {
     isThemeDialogOpen,

packages/cli/src/ui/themes/theme-manager.ts

@@ -19,8 +19,9 @@ export interface ThemeDisplay {
   active: boolean;
 }
 
+export const DEFAULT_THEME: Theme = VS2015;
+
 class ThemeManager {
-  private static readonly DEFAULT_THEME: Theme = VS2015;
   private readonly availableThemes: Theme[];
   private activeTheme: Theme;
 
@@ -35,7 +36,7 @@ class ThemeManager {
       XCode,
       ANSI,
     ];
-    this.activeTheme = ThemeManager.DEFAULT_THEME;
+    this.activeTheme = DEFAULT_THEME;
   }
 
   /**
@@ -52,10 +53,8 @@ class ThemeManager {
    * Sets the active theme.
    * @param themeName The name of the theme to activate.
    */
-  setActiveTheme(themeName: string): void {
-    const foundTheme = this.availableThemes.find(
-      (theme) => theme.name === themeName,
-    );
+  setActiveTheme(themeName: string | undefined): void {
+    const foundTheme = this.findThemeByName(themeName);
 
     if (foundTheme) {
       this.activeTheme = foundTheme;
@@ -64,6 +63,13 @@ class ThemeManager {
     }
   }
 
+  findThemeByName(themeName: string | undefined): Theme | undefined {
+    if (!themeName) {
+      return DEFAULT_THEME;
+    }
+    return this.availableThemes.find((theme) => theme.name === themeName);
+  }
+
   /**
    * Returns the currently active theme object.
    */