Teclado

main.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.dark().copyWith(
        scaffoldBackgroundColor: darkBlue,
      ),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Container(
          height: 176,
          color: Colors.white,
          child: Row(
            children: [
              Expanded(
                flex: 3,
                child: Column(
                  children: [
                    oneToNineButtons(),
                    Row(
                      children: [
                        _button('<-', 1, bgColor: Colors.orange),
                        _button('0', 2),
                      ],
                    ),
                  ],
                ),
              ),
              Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  _button('Cancelar', 2, bgColor: Colors.red, width: 80),
                  _button('Ok', 2, bgColor: Colors.grey, width: 80),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget oneToNineButtons() {
    return Column(
      children: [
        Row(
          children: [
            _button('1', 1),
            _button('2', 1),
            _button('3', 1),
          ],
        ),
        Row(
          children: [
            _button('4', 1),
            _button('5', 1),
            _button('6', 1),
          ],
        ),
        Row(
          children: [
            _button('7', 1),
            _button('8', 1),
            _button('9', 1),
          ],
        ),
      ],
    );
  }

  Widget _button(
    String label,
    int flex, {
    Color bgColor = Colors.white,
    double? width,
    VoidCallback? onPressed,
  }) {
    return Expanded(
      flex: flex,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: 2, vertical: 2),
        child: OutlinedButton(
          onPressed: onPressed,
          style: OutlinedButton.styleFrom(
            padding: const EdgeInsets.all(0),
            minimumSize: Size(width ?? 0, 48),
            backgroundColor: bgColor,
            side: const BorderSide(color: Colors.grey),
          ),
          child: Text(
            label,
            style: const TextStyle(
              color: Colors.black,
            ),
          ),
        ),
      ),
    );
  }
}