Реализации на С++

Abstract factory

Общая реализация на языке С++

BaseGraphics

class BaseGraphics 
{
public:
    virtual ~BaseGraphics() = 0;
};

BaseGraphics::~BaseGraphics() {}


class QtGraphics : public BaseGraphics
{
public:
	QtGraphics(shared_ptr<Image> im) 
	{
		cout << "Calling the QtGraphics constructor;" << endl; 
	}
	
	~QtGraphics() override 
	{ 
		cout << "Calling the QtGraphics destructor;" << endl; 
	}
};

AbstractGraphFactory

class AbstractGraphFactory
{
public:
	virtual ~AbstractGraphFactory() = default;

	virtual unique_ptr<BaseGraphics> createGraphics(shared_ptr<Image> im) = 0;
	virtual unique_ptr<BasePen> createPen(shared_ptr<Color> cl) = 0;
	virtual unique_ptr<BaseBrush> createBrush(shared_ptr<Color> cl) = 0;
};


class QtGraphFactory : public AbstractGraphFactory
{
public:
	unique_ptr<BaseGraphics> createGraphics(shared_ptr<Image> im) override
	{
		return make_unique<QtGraphics>(im);
	}

	unique_ptr<BasePen> createPen(shared_ptr<Color> cl) override
	{
		return make_unique<QtPen>();
	}

	unique_ptr<BaseBrush> createBrush(shared_ptr<Color> cl) override
	{
		return make_unique<QtBrush>();
	}
};

User

class User
{
public:
	void use(shared_ptr<AbstractGraphFactory>& cr)
	{
		shared_ptr<Image> image = make_shared<Image>();
		auto graphics = cr->createGraphics(image);
	}
};

Pen

class BasePen {};

class QtPen : public BasePen {};

Brush

class BaseBrush {};

class QtBrush : public BaseBrush {};

Image

class Image {};

Color

class Color {};

# include <iostream>
# include <memory>

using namespace std;

int main()
{
	shared_ptr<AbstractGraphFactory> grfactory = make_shared<QtGraphFactory>();

	unique_ptr<User> us = make_unique<User>();

	us->use(grfactory);
}