Abstract Factory Pattern

Overview

Use Case

• When you want to provide family of related objects without specifying their concrete classes.

Code

Product interface

    interface IButton
    {
        void Click();
    }
    interface ICheckbox
    {
        void Check();
    }
    class WinButton : IButton
    {
        public void Click()
        {
            Console.WriteLine("Windows button clicked.");
        }
    }
    class WinCheckbox : ICheckbox
    {
        public void Check()
        {
            Console.WriteLine("Windows checkbox checked.");
        }
    }
    class MacButton : IButton
    {
        public void Click()
        {
            Console.WriteLine("Mac button clicked.");
        }
    }
    class MacCheckbox : ICheckbox
    {
        public void Check()
        {
            Console.WriteLine("Mac checkbox checked.");
        }
    }

• Factory interface

      interface IGUIFactory
      {
          IButton CreateButton();
          ICheckbox CreateCheckbox();
      }
       class WinFactory : IGUIFactory
      {
          public IButton CreateButton()
          {
              return new WinButton();
          }
          public ICheckbox CreateCheckbox()
          {
              return new WinCheckbox();
          }
      }
  
      class MacFactory : IGUIFactory
      {
          public IButton CreateButton()
          {
              return new MacButton();
          }
          public ICheckbox CreateCheckbox()
          {
              return new MacCheckbox();
          }
      }
  

• Client code

      IGUIFactory factory = new MacFactory();
      var button = factory.CreateButton();
      button.Click();
      var checkbox = factory.CreateCheckbox();
      checkbox.Check();