#ifndef ELASINGLETON_H
#define ELASINGLETON_H

#include <QMutex>

template <typename T> class Singleton {
public:
    static T *getInstance();

private:
    Q_DISABLE_COPY(Singleton)
};

template <typename T> T *Singleton<T>::getInstance() {
    static QMutex mutex;
    QMutexLocker  locker(&mutex);
    static T     *instance = nullptr;
    if (instance == nullptr) {
        instance = new T();
    }
    return instance;
}

#define Q_SINGLETON_CREATE(Class)  \
private:                           \
    friend class Singleton<Class>; \
                                   \
public:                            \
    static Class *getInstance() { return Singleton<Class>::getInstance(); }

#define Q_SINGLETON_CREATE_H(Class) \
private:                            \
    static Class *_instance;        \
                                    \
public:                             \
    static Class *getInstance();

#define Q_SINGLETON_CREATE_CPP(Class)  \
    Class *Class::_instance = nullptr; \
    Class *Class::getInstance() {      \
        static QMutex mutex;           \
        QMutexLocker  locker(&mutex);  \
        if (_instance == nullptr) {    \
            _instance = new Class();   \
        }                              \
        return _instance;              \
    }

#endif // ELASINGLETON_H