import 'package:flutter/material.dart';
import 'package:quantity_input/quantity_input.dart';

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

class MyApp extends StatefulWidget {
  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int simpleIntInput = 0;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Example',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: SafeArea(
        child: Scaffold(
          appBar: AppBar(
            title: Text('Example')
          ),
          body: Center(
            child: Column(  
              mainAxisSize: MainAxisSize.min,
              children: [
                QuantityInput(
                  value: simpleIntInput,
                  onChanged: (value) => setState(() => simpleIntInput = int.parse(value.replaceAll(',', '')))
                ),
                Text(
                  'Value: $simpleIntInput',
                  style: TextStyle(
                    color: Colors.black,
                    fontWeight: FontWeight.bold
                  )
                )
              ]
            )
          )
        )
      )
    );
  }
}