Facade

#include <iostream>

using namespace std;

class GtkSystem
{
public:
    void Init(int argc, char** argv);
    int EventLoop() { cout<<"GtkSystem::EventLoop"<<endl; return 0; }
};

class QtSystem
{
public:
    void Init(int argc, char** argv);
    int EventLoop() { cout<<"QtSystem::EventLoop"<<endl; return 1; }
};

class LogSystem
{
public:
    static void Logger(const char* text) { cout<<"LogSystem::Logger["<<text<<"]"<<endl; }
}; 

class GuiFacade
{
public:
    GuiFacade();
    ~GuiFacade();
    int MainLoop();
    void Logger(const char* text);

private:
#ifdef GUI_WITH_GTK
    GtkSystem* m_pGuiSystem;
#else
    QtSystem* m_pGuiSystem;
#endif
    LogSystem* m_pLogSystem;
};

GuiFacade::GuiFacade()
{
#ifdef GUI_WITH_GTK
    m_pGuiSystem = new GtkSystem;
#else
    m_pGuiSystem = new QtSystem;
#endif
}

GuiFacade::~GuiFacade()
{
    delete m_pGuiSystem;
    m_pGuiSystem = NULL;
}

int GuiFacade::MainLoop()
{
    return m_pGuiSystem->EventLoop();
}

void GuiFacade::Logger(const char* text)
{
    LogSystem::Logger(text);
}

int main(int argc, char *argv[])
{
    GuiFacade facade;

    facade.Logger("GuiSystem Startup");
    facade.MainLoop();

    return 0;
}