Error when focussing on next Focus in Flutter - flutter

Question

If I click away from a TextField and then back on it and want to focus on the next TextField (using FocusScope.of(context).nextFocus()) by hitting enter on the software keyboard I get this error:
Exception has occurred.
_AssertionError ('package:flutter/src/widgets/focus_manager.dart': Failed assertion: line 790 pos 7: 'context != null': Tried to get the bounds of a focus node that didn't have its context set yet.
The context needs to be set before trying to evaluate traversal policies. Setting the context is typically done with the attach method.)
This is my code:
import 'package:quizlet/api/convert_json.dart';
import 'package:quizlet/style.dart';
class CreateQuiz extends StatefulWidget {
const CreateQuiz({super.key});
#override
State<CreateQuiz> createState() => _CreateQuizState();
}
class _CreateQuizState extends State<CreateQuiz> {
int wordCount = 3;
List errorDefinitions = [false, false, false];
List errorAnswers = [false, false, false];
bool errorTitle = false;
bool errorDescription = false;
final List definitions = [
TextEditingController(),
TextEditingController(),
TextEditingController()
];
final List answers = [
TextEditingController(),
TextEditingController(),
TextEditingController()
];
final title = TextEditingController();
final description = TextEditingController();
#override
Widget build(BuildContext context) {
double height = MediaQuery.of(context).size.height;
final brightness = MediaQuery.of(context).platformBrightness;
bool darkMode = brightness == Brightness.dark;
final hintColor = darkMode ? Colors.white : Colors.black;
return Scaffold(
appBar: AppBar(
title: const Text("Create Quiz"),
actions: [
TextButton(
style: TextButton.styleFrom(
foregroundColor: Colors.white,
),
onPressed: () {
onPressed();
},
child: Text(
"Done",
style: TextStyle(fontSize: height / 55),
),
),
],
),
body: GestureDetector(
behavior: HitTestBehavior.opaque,
onTap: () {
FocusScope.of(context).requestFocus(FocusNode());
},
child: Padding(
padding: const EdgeInsets.all(10.0),
child: ListView(
children: [
SizedBox(
height: height / 40,
),
TextField(
onSubmitted: (value) {
FocusScope.of(context).nextFocus();
},
onChanged: (value) {
setState(() {
errorTitle = false;
});
},
textInputAction: TextInputAction.next,
onEditingComplete: () {},
keyboardType: TextInputType.multiline,
controller: title,
decoration: InputDecoration(
contentPadding: const EdgeInsets.all(10.0),
hintStyle: TextStyle(
color: errorTitle ? Colors.red : hintColor,
),
hintText: errorTitle ? "Title can't be blank" : "Title",
border: const OutlineInputBorder(),
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(
color: errorTitle ? Colors.red : color1,
width: 2.0,
),
),
),
),
const SizedBox(
height: 5,
),
TextField(
onSubmitted: (value) {
FocusScope.of(context).nextFocus();
},
onChanged: (value) {
setState(() {
errorDescription = false;
});
},
textInputAction: TextInputAction.newline,
onEditingComplete: () {},
controller: description,
maxLines: null,
decoration: InputDecoration(
contentPadding: const EdgeInsets.all(10.0),
hintText: errorDescription
? "Description can't be blank"
: "Description",
hintStyle: TextStyle(
color: errorDescription ? Colors.red : hintColor,
),
border: const OutlineInputBorder(),
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(
color: errorDescription ? Colors.red : color1,
width: 2.0,
),
),
),
),
SizedBox(
height: height / 20,
),
ListView.builder(
shrinkWrap: true,
physics: const NeverScrollableScrollPhysics(),
itemCount: wordCount,
itemBuilder: (BuildContext context, int i) {
return Column(
children: [
TextField(
onSubmitted: (value) {
FocusScope.of(context).nextFocus();
},
onChanged: (value) {
setState(() {
errorDefinitions[i] = false;
});
},
textInputAction: TextInputAction.next,
onEditingComplete: () {},
autocorrect: false,
controller: definitions[i],
decoration: InputDecoration(
contentPadding: const EdgeInsets.all(10.0),
hintStyle: TextStyle(
color: errorDefinitions[i] ? Colors.red : hintColor,
),
hintText: errorDefinitions[i]
? "Definition can't be blank"
: "Definition",
border: const OutlineInputBorder(),
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(
color: errorDefinitions[i] ? Colors.red : color1,
width: 2.0,
),
),
),
),
const SizedBox(
height: 5,
),
TextField(
onSubmitted: (value) {
setState(() {
if (definitions[i].text != "" &&
answers[i].text != "") {
if (i + 2 >= wordCount) {
wordCount++;
definitions.add(TextEditingController());
answers.add(TextEditingController());
errorAnswers.add(false);
errorDefinitions.add(false);
}
FocusScope.of(context).nextFocus();
}
});
},
onChanged: (value) {
setState(() {
errorAnswers[i] = false;
});
},
textInputAction: TextInputAction.next,
onEditingComplete: () {},
autocorrect: false,
controller: answers[i],
decoration: InputDecoration(
contentPadding: const EdgeInsets.all(10.0),
hintStyle: TextStyle(
color: errorAnswers[i] ? Colors.red : hintColor,
),
hintText: errorAnswers[i]
? "Answer can't be blank"
: "Answer",
border: const OutlineInputBorder(),
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(
color: errorAnswers[i] ? Colors.red : color1,
width: 2.0,
),
),
),
),
SizedBox(
height: height / 50,
),
],
);
},
),
],
),
),
),
);
}```