JuLearn/lib/learn.dart

import 'package:flutter/material.dart';
import 'package:ju_learn/main.dart';

class QuizPage extends StatefulWidget {
  Vault v;
  QuizPage(this.v, {super.key});

  @override
  // ignore: no_logic_in_create_state, library_private_types_in_public_api
  _QuizPageState createState() {
    v.randomize();
    return _QuizPageState(v);
  }
}

class _QuizPageState extends State<QuizPage> {
  int _currentQuestionIndex = 0;
  int ask_state = -1;
  int _score = 0;
  Vault v;
  _QuizPageState(this.v);

  void _checkAnswer(int selectedIndex) {
    //if (selectedIndex == v.questions[_currentQuestionIndex].correct) {
    //  setState(() {
    //    _score++;
    //  });
    //}
    setState(() {
      ask_state = selectedIndex;
    });
  }

  void _nextQuestion() {
    setState(() {
      if (_currentQuestionIndex < v.questions.length - 1) {
        ask_state = -1;
        _currentQuestionIndex++;
      } else {
        _showResultDialog();
      }
    });
  }

  void _showResultDialog() {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Quiz Completed'),
          content: Text('Your score: $_score / ${v.questions.length}'),
          actions: [
            TextButton(
              child: const Text('Restart'),
              onPressed: () {
                setState(() {
                  _currentQuestionIndex = 0;
                  _score = 0;
                });
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Learning: ${v.name}'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            Text(
              v.questions[_currentQuestionIndex].quest,
              style: const TextStyle(
                fontSize: 20.0,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 20.0),
            ...v.questions[_currentQuestionIndex].answers.map(
              (option) {
                return Container(
                    margin: const EdgeInsets.symmetric(vertical: 8.0),
                    child: FilledButton(
                        onPressed: () => ask_state == -1
                            ? _checkAnswer(
                                v.questions[_currentQuestionIndex].answers
                                    .indexOf(option),
                              )
                            : _nextQuestion(),
                        child: Text(option),
                        style: FilledButton.styleFrom(
                          backgroundColor: ask_state == -1
                              ? null
                              : (v.questions[_currentQuestionIndex].correct ==
                                      v.questions[_currentQuestionIndex].answers
                                          .indexOf(option)
                                  ? Colors.green
                                  : Colors.red),
                        )));
              },
            ),
            if (ask_state != -1)
              Text(
                v.questions[_currentQuestionIndex].explanation,
                style: const TextStyle(
                  fontSize: 15.0,
                  fontWeight: FontWeight.bold,
                ),
              )
          ],
        ),
      ),
    );
  }
}