Design Pattern Abstract Factory

AbstractFactory.cpp

#include <iostream>
 
class Button {
public:
    virtual void paint() = 0;
    virtual ~Button() { }
};
 
class WinButton : public Button {
public:
    void paint() override {
        std::cout << "I'm a WinButton";
    }
    ~WinButton() { }
};
 
class OSXButton : public Button {
public:
    void paint() override {
        std::cout << "I'm an OSXButton";
    }
    ~OSXButton() { }
};
 
class GUIFactory {
public:
    virtual Button *createButton() = 0;
    virtual ~GUIFactory() { }
};
 
class WinFactory : public GUIFactory {
public:
    Button *createButton() override {
        return new WinButton();
    }
    ~WinFactory() { }
};
 
class OSXFactory : public GUIFactory {
public:
    Button *createButton() override {
        return new OSXButton();
    }
    ~OSXFactory() { }
};
 
class Application {
public:
    Application(GUIFactory *factory) {
        if (factory != NULL)
        {
            Button *button = factory->createButton();
            button->paint();
            delete button;
            delete factory;
        }
        else
        {
            std::cerr << "Fatal Error!!" << std::endl;
        }
    }
};
 
GUIFactory *createOsSpecificFactory() {
    int sys;
    std::cout << "Enter OS type (0: Windows, 1: MacOS X): ";
    std::cin >> sys;
 
    switch (sys)
    {
    case 0:
        return new WinFactory();
    case 1:
        return new OSXFactory();
    default:
        std::cerr << "The number you chose is out of range!!" << std::endl;
        return nullptr;
    }
}
 
int main() {
    Application application(createOsSpecificFactory());
 
    return 0;
}