Styles and Themes of Text

 import 'package:flutter/material.dart';

import 'package:practice/ui_helper/util.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "Hello Flutter Application",
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.lightGreen,
        textTheme: const TextTheme(
          displayLarge: TextStyle(fontSize: 30, fontWeight: FontWeight.bold),
          displayMedium: TextStyle(
              fontSize: 30,
              fontWeight: FontWeight.bold,
              color: Colors.lightGreen),
          titleMedium: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.w500,
              fontStyle: FontStyle.italic),
          titleSmall: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.w500,
              fontStyle: FontStyle.italic,
              color: Colors.orange),
        ),
      ),
      home: const FlutterApp(),
    );
  }
}

class FlutterApp extends StatelessWidget {
  const FlutterApp({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text(
          "Hello World",
          style: TextStyle(fontWeight: FontWeight.bold),
        ),
        centerTitle: true,
        backgroundColor: Colors.grey,
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              "Text 1",
              style: Theme.of(context)
                  .textTheme
                  .displayLarge!
                  .copyWith(color: Colors.orange),
            ),
            Text("Text 2",
                style: Theme.of(context)
                    .textTheme
                    .titleMedium), //"Theme.of" indicates Theme of Application.
            Text("Text 3",
                style: Theme.of(context)
                    .textTheme
                    .displayMedium), //"textTheme" indicates Theme of Text.
            //Text("Text 4", style: Theme.of(context).textTheme.titleSmall),
            //Text("Text 4", style: mTextStyle11()),

            /*When we add "mTextStyle11()", then "package:practice/ui_helper/util.dart"
              package will Automatically Import.*/

            //Text("Text 4", style: mTextStyle30()),
            Text(
              "Text 4",
              style: mTextStyle11(textColor: Colors.pink),
            ),
          ],
        ),
      ),
    );
  }
}