gistfile1.txt

// Copyright 2019 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

import 'package:flutter/material.dart';

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

class CenteredText extends StatelessWidget {
  const CenteredText(this.text, {super.key, required this.style});

  final TextStyle style;
  final String text;

  Size measureHeight(String text, TextStyle style, double maxWidth) {
    final textPainter = TextPainter(
        text: TextSpan(text: text, style: style),
        maxLines: 1,
        textDirection: TextDirection.ltr,
        textAlign: TextAlign.left);

    try {
      textPainter.layout();

      final height =
          textPainter.computeDistanceToActualBaseline(TextBaseline.ideographic);
      return Size(textPainter.width, height);
    } finally {
      textPainter.dispose();
    }
  }

  @override
  Widget build(BuildContext context) {
    return LayoutBuilder(builder: (context, constraints) {
      final size = measureHeight(text, style, constraints.maxWidth);

      return Stack(children: [
        Positioned(
            left: (constraints.maxWidth - size.width) / 2,
            top: (constraints.maxHeight - size.height) / 2,
            child: Text(text, style: style)),
      ]);
    });
  }
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    super.key,
    required this.title,
  });

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    final decoration1 = BoxDecoration(
        color: Colors.black,
        border: Border.all(color: Colors.red, width: 15),
        borderRadius: BorderRadius.circular(100));
    final decoration2 = BoxDecoration(
        color: Colors.black, borderRadius: BorderRadius.circular(100));

    final style = TextStyle(
        fontSize: 150, color: Colors.white, height: 1, fontFamily: "Helvetica");

    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(mainAxisSize: MainAxisSize.min, children: [
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
                  decoration: decoration1,
                  height: 160,
                  width: 400,
                  child: Center(child: Text("123", style: style))),
              SizedBox(width: 10),
              Container(
                  decoration: decoration1,
                  height: 160,
                  width: 400,
                  child: CenteredText("123", style: style)),
            ],
          ),
          SizedBox(height: 10),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
                  decoration: decoration2,
                  height: 160,
                  width: 400,
                  child: Center(child: Text("123", style: style))),
              SizedBox(width: 10),
              Container(
                  decoration: decoration2,
                  height: 160,
                  width: 400,
                  child: CenteredText("123", style: style)),
            ],
          ),
        ]),
      ),
    );
  }
}