Checkbox

sample.packages.flutter.lib.src.material.checkbox.30.

This example shows how you can override the default theme of of a [Checkbox] with a [MaterialStateProperty]. In this example, the checkbox's color will be Colors.blue when the [Checkbox] is being pressed, hovered, or focused. Otherwise, the checkbox's color will be Colors.red.

  
import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const Center(
          child: MyStatefulWidget(),
        ),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State {
  bool isChecked = false;

  @override
  Widget build(BuildContext context) {
    Color getColor(Set states) {
      const Set interactiveStates = {
        MaterialState.pressed,
        MaterialState.hovered,
        MaterialState.focused,
      };
      if (states.any(interactiveStates.contains)) {
        return Colors.blue;
      }
      return Colors.red;
    }

    return Checkbox(
      checkColor: Colors.white,
      fillColor: MaterialStateProperty.resolveWith(getColor),
      value: isChecked,
      onChanged: (bool? value) {
        setState(() {
          isChecked = value!;
        });
      },
    );
  }
}