FocusNodes and Navigator problem

FocusNodesVisualGlitch.dart

import 'package:flutter/material.dart';

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

class TestApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark(),
      home: TestScreen(),
    );
  }
}

class TestScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: Container(
      child: Center(
        child: RaisedButton(
            onPressed: () => _pushSecondScreen(context),
            child: Text('Push to a new screen')),
      ),
    ));
  }

  void _pushSecondScreen(BuildContext context) {
    Navigator.of(context).push(MaterialPageRoute(builder: (_) => SecondTest()));
  }
}

class SecondTest extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Second Screen'),
      ),
      body: ListView(
        padding: EdgeInsets.all(20.0),
        children: List<Widget>.generate(10, (i) => _buildTextField(i)),
      ),
    );
  }

  Widget _buildTextField(int index) {
    // The custom focus node is thrown in here for example, but in a real world app,
    // a reference to the node would be kept so the app can manage focus between the nodes
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8.0),
      child: TextField(
        focusNode: FocusNode(),
        decoration: InputDecoration(
            labelText: 'Field $index',
            filled: true,
            border: OutlineInputBorder(
                borderRadius: BorderRadius.all(Radius.circular(5.0)))),
      ),
    );
  }
}