Question

I am not very experienced with OOP so I wanted to share what I am currently doing and ask for some advice about how I should go about a couple of things.

I am currently working on a simple game that uses a 2d grid. Here is a quick overview of my class structure:

• ‘GameBoard’- has an array of the possible cell states for the game, and methods that implement the rules.
• ‘GameView’ – has the superclass NSView, and is placed in my window as a custom view. This class is intended to read from the game board and draw the contents of the array by mapping the stares to an enumeration of images in its drawRect: method.
• ‘GameController’ – this is an intermediate class intended to initialise the game board and view, and handle the various UI controls. This class has instance variables of the ‘GameBoard’ and ‘GameView’ type.

Originally, I was doing nearly everything in the View class, and had it working fine but it started to get hard really to follow, which was my main reason for wanting to spread my code over a new class.

I have created a method in ‘GameController’ that initialises a new game, with some user defined parameters (removed in the snippet to save space).

-(IBACTION)initialiseGame:(id)sender {
    gameBoard = [[GameBoard alloc] init...];
    gameView = [[GameView alloc] init...];
}

What I want to do here is pass the game view a pointer to the game board instance so that I can read it’s array to draw the current state of the game, something like:

-(void)initWithGameBoard:(GameBoard*)gameBoard;

Is this the right way of going about that, or should I be doing this in a different way?

My next problem with moving to the controller class is that I cannot seem to find out how to do is get a pointer to the instance of GameView that I have placed on the window in IB? Would it be better to not place the view on the window in interface builder, and instead place it on the window programatically in the initialiseGame function? If so how would I go about doing that?

I guess one other question would be, should I just scrap this idea and stick to doing everything in the GameDraw class?

Thank you very much for taking your time to read this, this is probably a very simple question to any experienced object-oriented programmer, but I cannot seem to find the answers specifically anywhere.

Answer 1

There’s more than one way to do make this work, but here’s how I would do it:

1. Instantiate the view once in IB. Don’t invoke alloc/init yourself.
2. In your view controller, make an outlet for your view and connect it in Interface Builder. That’s how your controller will get access to it. Your view controller will need to be the file owner — probably it already is.
3. Design the view to be reusable. Give it a -setGameBoard: method for the controller to invoke. Make sure the view can draw something blank when it doesn’t have a game board.

4. Write -initializeGame: like this:

   -(IBAction) initialiseGame:(id) sender {
       gameBoard = [[GameBoard alloc] init...];
       [gameView setGameBoard:gameBoard];
   }