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

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

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  final _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    var validator = MultiValidator([
      RequiredValidator(errorText: 'This field is required'),
    ]);
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Container(
          child: Form(
            key: _formKey,
            child: Column(
              children: [
                TextFormField(
                  validator: validator,
                  decoration: InputDecoration(
                    contentPadding: EdgeInsets.zero,
                    border: const OutlineInputBorder(),
                    hintText: 'Hint Text',
                    error: Transform.translate(
                        offset: const Offset(-10, 0),
                        child: const Text('Error Text')),
                  ),
                ),
                ElevatedButton(
                  onPressed: () {
                    // Validate returns true if the form is valid, or false otherwise.
                    if (_formKey.currentState!.validate()) {
                      // If the form is valid, display a snackbar. In the real world,
                      // you'd often call a server or save the information in a database.
                      ScaffoldMessenger.of(context).showSnackBar(
                        const SnackBar(content: Text('Processing Data')),
                      );
                    }
                  },
                  child: const Text('Submit'),
                ),
              ],
            ),
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: null,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}