Abstract Factory.cpp

#include <iostream>
#include <memory>

// Abstract Product A
class Button {
public:
    virtual void paint() const = 0;
    virtual ~Button() = default;
};

// Abstract Product B
class Checkbox {
public:
    virtual void paint() const = 0;
    virtual ~Checkbox() = default;
};

// Concrete Products for Family 1: Windows
class WindowsButton : public Button {
public:
    void paint() const override { std::cout << "Render Windows Button\n"; }
};

class WindowsCheckbox : public Checkbox {
public:
    void paint() const override { std::cout << "Render Windows Checkbox\n"; }
};

// Concrete Products for Family 2: macOS
class MacButton : public Button {
public:
    void paint() const override { std::cout << "Render macOS Button\n"; }
};

class MacCheckbox : public Checkbox {
public:
    void paint() const override { std::cout << "Render macOS Checkbox\n"; }
};

// Abstract Factory: Defines creation methods for all family members
class GUIFactory {
public:
    virtual std::unique_ptr<Button> createButton() const = 0;
    virtual std::unique_ptr<Checkbox> createCheckbox() const = 0;
    virtual ~GUIFactory() = default;
};

// Concrete Factory 1: Windows Family
class WindowsFactory : public GUIFactory {
public:
    std::unique_ptr<Button> createButton() const override {
        return std::make_unique<WindowsButton>();
    }
    std::unique_ptr<Checkbox> createCheckbox() const override {
        return std::make_unique<WindowsCheckbox>();
    }
};

// Concrete Factory 2: macOS Family
class MacFactory : public GUIFactory {
public:
    std::unique_ptr<Button> createButton() const override {
        return std::make_unique<MacButton>();
    }
    std::unique_ptr<Checkbox> createCheckbox() const override {
        return std::make_unique<MacCheckbox>();
    }
};

void renderUI(const GUIFactory& factory) {
    auto button = factory.createButton();
    auto checkbox = factory.createCheckbox();
    
    button->paint();
    checkbox->paint();
}

int main() {
    std::cout << "--- Building Windows UI ---\n";
    WindowsFactory winFactory;
    renderUI(winFactory);

    std::cout << "\n--- Building macOS UI ---\n";
    MacFactory macFactory;
    renderUI(macFactory);

    return 0;
}