UI and logic separation

Question

Hi I want to write a simple game application for example Chess or Monopoly. I want to have to separate classes Game and UI. I wonder what is the best way to communicate between thees two classes. By events? By saving reference to ui in Game object ? I want to separate the logic from ui. any comments are appreciated. thnx.

Sam Hobbs · Answer

Don't use exceptions for normal events. You will need to use events for anything that the game player does such as move the mouse or click it or presse a key. I would design it so that the game logic calls the UI. I think it would be good design for the game logic to know about the UI. The UI should exist for the details of the UI; the main logic would not be in the UI. In business software a popular philosophy is to use three layers; a Data Access Layer (DAL) a Business Layer Logic (BLL) and the UI. You can search for articles about that; there are even books about it. It is probably relevant to games also.

Eduard G · Answer

Thank you for the answer but the question is what is the best way to let UI know that player1 has won the game for example? Is it OK to keep the reference to the Game objec in the UI controll or to keep UI reference in the Game controll or notify UI by fireing an event or throwing an exception?

Sam Hobbs · Answer

You can create the UI as a UserControl and the game in a separate application. The control can be part of a control library in a control library project. Or you can create your game logic in a class and the class can be in a class library in a separate project and the application would have the UI in it and call the game logic in the separate class. Or you can create both a control library and a class library and then a third application that uses them.