question_screen.dart

import 'package:flutter/material.dart';
import 'package:quiz_app/answer_button.dart';
import 'package:quiz_app/data/questions.dart';

class QuestionScreen extends StatefulWidget {
  const QuestionScreen({
    super.key,
    required this.onSelectAnswer,
  });

  final void Function(String answer) onSelectAnswer;

  @override
  State<QuestionScreen> createState() {
    return _QuestionScreen();
  }
}

class _QuestionScreen extends State<QuestionScreen> {
  var currentQuestionIndex = 0;
  void answerQuestion(String selectedAnswer) {
    widget.onSelectAnswer(selectedAnswer);
    // currentQuestionIndex = currentQuestionIndex + 1;
    // currentQuestionIndex += 1; // Here the value can be set manually eg. variable  += 2
    setState(() {
      currentQuestionIndex++; // increments the value by 1 and only by 1
    });
  }

  @override
  Widget build(context) {
    final currentQuestion = questions[currentQuestionIndex];

    return SizedBox(
      width: double.infinity, // Using as much width as available
      child: Container(
        margin: const EdgeInsetsDirectional.all(40),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              currentQuestion.text,
              style: TextStyle(
                color: const Color.fromARGB(255, 201, 163, 249),
                fontSize: 24,
                fontWeight: FontWeight.bold,
              ),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 30),
            ...currentQuestion.getShuffleAnswers().map(
              (answer) {
                return AnswerButton(
                  answerText: answer,
                  onTap: () {
                    answerQuestion(answer);
                  },
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}