Question

I have a View Controller that initializes a UIView as its view. That view initializes another UIView as a subview. Both UIViews communicate with the View Controller through a delegate/protocol.

Each UIView creates an instance of the ViewController and makes it equal to the delegate:

ViewController *aDelegate = [[ViewController alloc] init];
self.delegate = aDelegate;

PROBLEM: The View Controller has a variable called (int)selection that is modified by both UIViews. Both views must know how each other modified the variable, but since each has a different instance of the View Controller that communication is impossible. How would I fix this problem?

Thanks a ton

EDIT: Peter mentioned assigning the delegate at the views creation which I like, but how would I do that for the subview since it is created in the UIView and not the View Controller. PS. In reality it is a subview of a subview of a subview so can I create them all in the View Controller and then assign it as the delegate?

Tried assigning the delegate as follows but it continually crashes when I attempt to call a ViewController method from the view:

MyView *mainView = [[MyView alloc] initWithFrame:frame];
self.view = mainView;
mainView.delegate = self;
[mainView release];

Answer 1

The views does not need to know about each other. In your view controller you define a property for the sub view

@property (nonatomic, retain) MyView *myView;

Then you create your sub view and assign the delegate. This can be done in viewDidLoad

- (void)viewDidLoad {
    [super viewDidLoad];

    CGRect frame = ...;
    MyView *subView = [[MyView alloc] initWithFrame:frame];
    self.myView = subView;
    subView.delegate = self;
    [self.view addSubView:subView];
    [subView release];


    self.view.delegate = self;
} 

Then in your delegate method, which I just guessed how it could look, you can update the view controller as well as the other view.

- (void)view:(MyView *)view didUpdateSelection:(int)newSelection {
    self.selection = newSelection;
    if (view == self.view) {
        self.myView.selection = newSelection;
    }
    else {
        self.view.selection = newSelection;
    }
}