content: import 'package:flutter/material.dart';
  
  /// Widget using [ToggleButtons) that can be used to toggle the theme mode
  /// of an application.
  ///
  /// This is a simple Flutter "Universal" Widget that only depends on the SDK and
  /// can be dropped into any application.
  class ThemeModeSwitch extends StatelessWidget {
    const ThemeModeSwitch({
      super.key,
      required this.themeMode,
      required this.onChanged,
    });
    final ThemeMode themeMode;
    final ValueChanged<ThemeMode> onChanged;
  
    @override
    Widget build(BuildContext context) {
      final List<bool> isSelected = <bool>[
        themeMode == ThemeMode.light,
        themeMode == ThemeMode.system,
        themeMode == ThemeMode.dark,
      ];
      return ToggleButtons(
        isSelected: isSelected,
        onPressed: (int newIndex) {
          if (newIndex == 0) {
            onChanged(ThemeMode.light);
          } else if (newIndex == 1) {
            onChanged(ThemeMode.system);
          } else {
            onChanged(ThemeMode.dark);
          }
        },
        children: const <Widget>[
          Icon(Icons.wb_sunny),
          Icon(Icons.phone_iphone),
          Icon(Icons.bedtime),
        ],
      );
    }
  }
  