A Text field will 'hide' the so-called persistent FooterButtons

Scaffold_TextFooterButtons.dart

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

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

class MyApp extends StatefulWidget {
  MyApp({Key key}) : super(key: key);
  State createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  int _count = 0;

  @override
  Widget build(BuildContext context) {
    final title = 'Floating App Bar';

    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: title,
      home: Scaffold(
        appBar: AppBar(
          title: Text('Sample Code'),
        ),
        body: Center(
            child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text('You have pressed the button $_count times.'),
            TextField(
              decoration: InputDecoration(
                hintText: 'Text field to type anything',
              ),
            ),
          ],
        )),
        bottomNavigationBar: BottomAppBar(
          child: Container(
            height: 50.0,
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () => setState(() {
                _count++;
              }),
          tooltip: 'Increment Counter',
          child: Icon(Icons.add),
        ),
        floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,
        persistentFooterButtons: <Widget>[
          IconButton(icon: Icon(Icons.insert_emoticon), onPressed: () {}),
          IconButton(icon: Icon(Icons.mood), onPressed: () {}),
          IconButton(icon: Icon(Icons.mood_bad), onPressed: () {}),
          IconButton(
              icon: Icon(Icons.sentiment_dissatisfied), onPressed: () {}),
          IconButton(icon: Icon(Icons.sentiment_neutral), onPressed: () {}),
          IconButton(icon: Icon(Icons.sentiment_satisfied), onPressed: () {}),
          IconButton(
              icon: Icon(Icons.sentiment_very_dissatisfied), onPressed: () {}),
        ],
      ),
    );
  }
}