concrete_factory.swift

class WinFactory : AbstractGUIFactory {
    func createButton() -> Button {
        return WinButton()
    }
    
    func createWindow() -> Window {
        return WinWindow()
    }
}

class OSXFactory : AbstractGUIFactory {
    func createButton() -> Button {
        return OSXButton()
    }
    
    func createWindow() -> Window {
        return OSXWindow()
    }
}