In-App purchasing demo | Qt 6.2

- Qt 6.2
- In-App purchasing demo
- Qt 6.2.3 Reference Documentation

# In-App purchasing demo

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     #include <QFile>
     #include <QDebug>
     #include <QBuffer>
     #include <QRandomGenerator>
     #include <QtConcurrent/QtConcurrentRun>
     #include <mutex>

     #include "hangmangame.h"

     HangmanGame::HangmanGame(QObject *parent)
         : QObject(parent)
         , m_vowelsUnlocked(false)
     {
         connect(this, &HangmanGame::vowelBought, this, &HangmanGame::registerLetterBought);
         (void) QtConcurrent::run(&HangmanGame::initWordList, this);

         m_vowelsUnlocked = m_persistentSettings.value("Hangman/vowelsUnlocked", false).toBool();
         m_vowelsAvailable = m_persistentSettings.value("Hangman/vowelsAvailable", 0).toInt();
         m_wordsGiven = m_persistentSettings.value("Hangman/wordsGiven", 0).toInt();
         m_wordsGuessedCorrectly = m_persistentSettings.value("Hangman/wordsGuessedCorrectly", 0).toInt();
         m_score = m_persistentSettings.value("Hangman/score", 0).toInt();
     }

     void HangmanGame::reset()
     {
         m_lettersOwned.clear();
         emit lettersOwnedChanged();
         emit errorCountChanged();
         chooseRandomWord();
     }

     void HangmanGame::reveal()
     {
         m_lettersOwned += vowels() + consonants();
         emit errorCountChanged();
         emit lettersOwnedChanged();
     }

     void HangmanGame::gameOverReveal()
     {
         m_lettersOwned += vowels() + consonants();
         emit lettersOwnedChanged();
     }

     void HangmanGame::requestLetter(const QString &letterString)
     {
         Q_ASSERT(letterString.size() == 1);
         QChar letter = letterString.at(0);
         registerLetterBought(letter);
     }

     void HangmanGame::guessWord(const QString &word)
     {
         if (word.compare(m_word, Qt::CaseInsensitive) == 0) {
             //Determine how many vowels were earned
             setVowelsAvailable(m_vowelsAvailable + calculateEarnedVowels());
             //score is number of remaining consonants + remaining errors
             setScore(m_score + calculateEarnedPoints());
             m_lettersOwned += m_word.toUpper();
         } else {
             // Small hack to get an additional penalty for guessing wrong
             static int i=0;
             Q_ASSERT(i < 10);
             m_lettersOwned += QString::number(i++);
             emit errorCountChanged();
         }
         emit lettersOwnedChanged();
     }

     bool HangmanGame::isVowel(const QString &letter)
     {
         Q_ASSERT(letter.size() == 1);
         QChar letterChar = letter.at(0);
         return vowels().contains(letterChar);
     }

     QString HangmanGame::vowels() const
     {
         return QStringLiteral("AEIOU");
     }

     QString HangmanGame::consonants() const
     {
         return QStringLiteral("BCDFGHJKLMNPQRSTVWXYZ");
     }

     int HangmanGame::errorCount() const
     {
         int count = 0;
         for (QChar c : m_lettersOwned) {
             if (!m_word.contains(c))
                 ++count;
         }
         return count;
     }

     bool HangmanGame::vowelsUnlocked() const
     {
         return m_vowelsUnlocked;
     }

     void HangmanGame::setVowelsUnlocked(bool vowelsUnlocked)
     {
         if (m_vowelsUnlocked != vowelsUnlocked) {
             m_vowelsUnlocked = vowelsUnlocked;
             m_persistentSettings.setValue("Hangman/vowelsUnlocked", m_vowelsUnlocked);
             emit vowelsUnlockedChanged(m_vowelsUnlocked);
         }
     }

     int HangmanGame::vowelsAvailable() const
     {
         return m_vowelsAvailable;
     }

     int HangmanGame::wordsGiven() const
     {
         return m_wordsGiven;
     }

     int HangmanGame::wordsGuessedCorrectly() const
     {
         return m_wordsGuessedCorrectly;
     }

     int HangmanGame::score() const
     {
         return m_score;
     }

     void HangmanGame::setScore(int score)
     {
         if (m_score != score) {
             m_score = score;
             m_persistentSettings.setValue("Hangman/score", m_score);
             emit scoreChanged(score);
         }
     }

     void HangmanGame::setWordsGiven(int count)
     {
         if (m_wordsGiven != count) {
             m_wordsGiven = count;
             m_persistentSettings.setValue("Hangman/wordsGiven", m_wordsGiven);
             emit wordsGivenChanged(count);
         }
     }

     void HangmanGame::setWordsGuessedCorrectly(int count)
     {
         if (m_wordsGuessedCorrectly != count) {
             m_wordsGuessedCorrectly = count;
             m_persistentSettings.setValue("Hangman/wordsGuessedCorrectly", m_wordsGuessedCorrectly);
             emit wordsGuessedCorrectlyChanged(count);
         }
     }

     void HangmanGame::setVowelsAvailable(int count)
     {
         if (m_vowelsAvailable != count) {
             m_vowelsAvailable = count;
             m_persistentSettings.setValue("Hangman/vowelsAvailable", m_vowelsAvailable);
             emit vowelsAvailableChanged(count);
         }
     }

     void HangmanGame::registerLetterBought(const QChar &letter)
     {
         if (m_lettersOwned.contains(letter))
             return;

         m_lettersOwned.append(letter);
         emit lettersOwnedChanged();

         if (!m_word.contains(letter))
             emit errorCountChanged();
     }

     void HangmanGame::chooseRandomWord()
     {
         const std::lock_guard<QRecursiveMutex> locker(m_lock);
         if (m_wordList.isEmpty())
             return;

         m_word = m_wordList.at(QRandomGenerator::global()->bounded(m_wordList.size()));
         emit wordChanged();
     }

     void HangmanGame::initWordList()
     {
         const std::lock_guard<QRecursiveMutex> locker(m_lock);
         QFile file(":/dict.txt");
         if (file.open(QIODevice::ReadOnly)) {
             QByteArray allData = file.readAll();
             QBuffer buffer(&allData);
             if (!buffer.open(QIODevice::ReadOnly))
                 qFatal("Couldn't open buffer for reading!");

             while (!buffer.atEnd()) {
                 QByteArray ba = buffer.readLine().trimmed().toUpper();
                 if (!ba.isEmpty() && ba.length() < 10)
                     m_wordList.append(QString::fromLatin1(ba));
             }
         }

         chooseRandomWord();
     }

     int HangmanGame::calculateEarnedVowels()
     {
         int total = 0;
         for (int i = 0; i < m_word.length(); ++i) {
             if (isVowel(QString(m_word[i])) && !m_lettersOwned.contains(QString(m_word[i])))
                 total++;
         }
         return total;
     }

     int HangmanGame::calculateEarnedPoints()
     {
         int total = 0;
         for (int i = 0; i < m_word.length(); ++i) {
             if (consonants().contains(QString(m_word[i])) && !m_lettersOwned.contains(QString(m_word[i])))
                 total++;
         }
         total += 8 - errorCount();
         return total;
     }