using System;

​

public interface IWidget

{

    void Render();

}

public interface IButton: IWidget {}

public interface ITextbox: IWidget {}

​

public class MaterialButton: IButton

{

    public void Render()

    {

        Console.WriteLine("Material Button");

    }

}

public class MaterialTextbox : ITextbox

{

    public void Render()

    {

        Console.WriteLine("Material Textbox");

    }

}

​

public class AntButton : IButton

{

    public void Render()

    {

        Console.WriteLine("Ant Button");

    }

}

public class AntTextbox: ITextbox

{

    public void Render()

    {

        Console.WriteLine("Ant Textbox");

    }

}

​

public enum Theme

{

    Material,

    Ant

}

​

public interface IWidgetFactory

{

    IButton CreateButton();

    ITextbox CreateTextbox();

}

​

public class MaterialWidgetFactory : IWidgetFactory

{

    public IButton CreateButton()

    {

        return new MaterialButton();

    }

​

    public ITextbox CreateTextbox()

    {

        return new MaterialTextbox();

    }

}

public class AntWidgetFactory : IWidgetFactory

{

    public IButton CreateButton()

    {

        return new AntButton();

    }

​

    public ITextbox CreateTextbox()

    {

        return new AntTextbox();

    }

}

​

public class ContactForm

{

    public void Render(IWidgetFactory widgetFactory) 

    {

        widgetFactory.CreateTextbox().Render();

        widgetFactory.CreateButton().Render();

    }

}

​

public class Program

{

    public static void Main()

    {

        new ContactForm().Render(new MaterialWidgetFactory());

    }

}