TextStyle basic usage

text_style_demo.dart

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.light().copyWith(
        scaffoldBackgroundColor: darkBlue,
        textTheme: const TextTheme(
          headline4: TextStyle(
            color: Colors.white,
          ),
        ),
      ),
      debugShowCheckedModeBanner: false,
      // Default functionality with a Scaffold, which provides a Material widget
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
      // Comment the above and uncomment the below to enjoy Flutter's jarring default
      // TextStyle, meant to be unattractive so you choose your own values!
      // home: Center(child: const Text('Error theme', style: TextStyle(color: Colors.blue))),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Text(
          'Hello, World!',
          style: Theme.of(context).textTheme.headline4,
        ),
        Text(
          'Hello, World!',
          style: Theme.of(context).textTheme.headline4!.copyWith(
                color: Colors.red,
                fontStyle: FontStyle.italic,
              ),
        ),
        const Text(
          'Hello, Flutter!',
          style: TextStyle(color: Colors.blue, fontSize: 48),
        ),
        const Text(
          'inherit: true (the default)',
          style: TextStyle(),
        ),
        const Text(
          'inherit: false',
          style: TextStyle(inherit: false),
        ),
      ],
    );
  }
}