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

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

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

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  final TextEditingController _controller = TextEditingController();
  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }
  
  @override
  void dispose(){
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
            decoration: InputDecoration(
            labelText: "Type more than 9 Characters, then try to use the backspace key",
            ),
            controller: _controller,
            onChanged: (value){
              
              print(_controller.text);
            },
            maxLength: 9,
            ),
          ],
        ),
      ),
    );
  }
}