In-App purchasing demo

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 #ifndef HANGMANGAME_H
 #define HANGMANGAME_H

 #include <QObject>
 #include <QStringList>
 #include <QMutex>
 #include <QSettings>
 #include <QtQml/qqml.h>

 #include "purchasing/inapp/inappproduct.h"
 #include "purchasing/inapp/inapppurchasebackend.h"
 #include "purchasing/inapp/inappstore.h"
 #include "purchasing/inapp/inapptransaction.h"
 #include "purchasing/qmltypes/inappproductqmltype.h"
 #include "purchasing/qmltypes/inappstoreqmltype.h"

 class HangmanGame : public QObject
 {
     Q_OBJECT
     Q_PROPERTY(QString word READ word NOTIFY wordChanged)
     Q_PROPERTY(QString lettersOwned READ lettersOwned NOTIFY lettersOwnedChanged)
     Q_PROPERTY(QString vowels READ vowels CONSTANT)
     Q_PROPERTY(QString consonants READ consonants CONSTANT)
     Q_PROPERTY(int errorCount READ errorCount NOTIFY errorCountChanged)
     Q_PROPERTY(bool vowelsUnlocked READ vowelsUnlocked WRITE setVowelsUnlocked NOTIFY vowelsUnlockedChanged)
     Q_PROPERTY(int vowelsAvailable READ vowelsAvailable WRITE setVowelsAvailable NOTIFY vowelsAvailableChanged)
     Q_PROPERTY(int wordsGiven READ wordsGiven WRITE setWordsGiven NOTIFY wordsGivenChanged)
     Q_PROPERTY(int  wordsGuessedCorrectly READ wordsGuessedCorrectly WRITE setWordsGuessedCorrectly NOTIFY wordsGuessedCorrectlyChanged)
     Q_PROPERTY(int score READ score WRITE setScore NOTIFY scoreChanged)
     QML_NAMED_ELEMENT(Hangman)

 public:
     explicit HangmanGame(QObject *parent = 0);
     Q_INVOKABLE void reset();
     Q_INVOKABLE void reveal();
     Q_INVOKABLE void gameOverReveal();
     Q_INVOKABLE void requestLetter(const QString &letterString);
     Q_INVOKABLE void guessWord(const QString &word);
     Q_INVOKABLE bool isVowel(const QString &letter);
     Q_INVOKABLE void setVowelsAvailable(int count);
     Q_INVOKABLE void setWordsGiven(int count);
     Q_INVOKABLE void setWordsGuessedCorrectly(int count);
     Q_INVOKABLE void setScore(int score);

     QString word() const { return m_word; }
     QString lettersOwned() const { return m_lettersOwned; }
     QString vowels() const;
     QString consonants() const;
     int errorCount() const;
     bool vowelsUnlocked() const;
     void setVowelsUnlocked(bool vowelsUnlocked);
     int vowelsAvailable() const;
     int wordsGiven() const;
     int wordsGuessedCorrectly() const;
     int score() const;

 signals:
     void wordChanged();
     void lettersOwnedChanged();
     void errorCountChanged();
     void vowelBought(const QChar &vowel);
     void purchaseWasSuccessful(bool wasSuccessful);
     void vowelsUnlockedChanged(bool unlocked);
     void vowelsAvailableChanged(int arg);
     void wordsGivenChanged(int arg);
     void wordsGuessedCorrectlyChanged(int arg);
     void scoreChanged(int arg);

 private slots:
     void registerLetterBought(const QChar &letter);

 private:
     void chooseRandomWord();
     void initWordList();
     int calculateEarnedVowels();
     int calculateEarnedPoints();

     QString m_word;
     QString m_lettersOwned;
     QStringList m_wordList;
     QRecursiveMutex m_lock;
     bool m_vowelsUnlocked;
     QSettings m_persistentSettings;
     int m_vowelsAvailable;
     int m_wordsGiven;
     int m_wordsGuessedCorrectly;
     int m_score;
 };

 #endif // HANGMANGAME_H