import 'package:flutter/material.dart';
import 'package:provider/provider.dart'; // .yaml file provider: ^3.1.0+1

void main() {
  runApp(MaterialApp(
    title: 'Navigation Basics',
    home: FirstRoute(),
  ));
}


class FirstRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      builder: (context) => Data(),
      child: Scaffold(
        appBar: AppBar(
          title: Text('First Route'),
        ),
        body: Column(
          children: <Widget>[
            Container(
              width: 256,
              margin: const EdgeInsets.only(bottom: 8),
              child: TextField(
                decoration: InputDecoration(
                    hintText: 'Enter user name', labelText: 'User Name'),
                onChanged: (String newUserName){
                  Provider.of<Data>(context).changePassword(newUserName);
                  print(newUserName);
                },
              ),
            ),
            Container(
              width: 256,
              margin: const EdgeInsets.only(bottom: 8),
              child: TextField(
                obscureText: true,
                decoration: InputDecoration(
                    hintText: 'Enter password', labelText: 'Password'),
                onChanged: (String newPassword){
                  Provider.of<Data>(context).changePassword(newPassword);
                  print(newPassword);
                },
              ),
            ),
            Center(
              child: RaisedButton(
                child: Text('Open route'),
                onPressed: () {
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => SecondRoute()),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class SecondRoute extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Second Route"),
      ),
      body: Column(
        children: <Widget>[
          Center(
            child: RaisedButton(
              onPressed: () {
                Navigator.pop(context);
              },
              child: Text('Go back!'),
            ),
          ),
          Text(
            Provider.of<Data>(context).userName,
//            Provider.of<String>(context),
            style: TextStyle(
                color: Colors.blue,
                fontSize: 20.0
            ),
          ),
          Text(
            Provider.of<Data>(context).password,
//            Provider.of<String>(context),
            style: TextStyle(
                color: Colors.green,
                fontSize: 20.0
            ),
          ),
        ],
      ),
    );
  }
}