`ToggleButtons` fill color switcher

toggle_buttons_fill_colors.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MainApp());
}

enum Buttons {
  android,
  iOS,
}

class MainApp extends StatefulWidget {
  const MainApp({super.key});

  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {
  late final ValueNotifier<List<bool>> _states;

  @override
  void dispose() {
    _states.dispose();
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
    _states = ValueNotifier(
        Buttons.values.map((button) => button.index == 0).toList());
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: ValueListenableBuilder(
            valueListenable: _states,
            builder: (context, states, child) {
              final selectedIndex = states.indexOf(true);
              return ToggleButtons(
                isSelected: states,
                selectedColor: theme.colorScheme.surface,
                fillColor: selectedIndex == 0
                    ? theme.colorScheme.primary
                    : theme.colorScheme.tertiary,
                onPressed: (index) {
                  _states.value = Buttons.values
                      .map((button) => button.index == index)
                      .toList();
                },
                children: [
                  ...Buttons.values.map((button) => Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: Text(button.name),
                      )),
                ],
              );
            },
          ),
        ),
      ),
    );
  }
}