Retaining rootViewController?

Question

I wonder if someone can help me out with regards to the memory management in the code below. I am particularly interested in rootController, does it get retained when I do initWithRootViewController or does it instead (which is my guess) get retained with window addSubView: I am just curious what is happening ...

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    Base_TableViewController *rootController = [[Base_TableViewController alloc] init];
    navController = [[UINavigationController alloc] initWithRootViewController:rootController];
    [window addSubview:[navController view]];
    [window makeKeyAndVisible];

    [rootController release];
    return YES;
}

- (void)dealloc {
    [navController release];
    [window release];
    [super dealloc];
}

EDIT:

So essentially the code above is correct, the release at the bottom cancels out the alloc at the top, "rootController" is retained by navController?

Many thanks, much appreciated.

Gary

Answer 1

After the call to alloc init, the retain count on rootController will be one. If navController does a retain in it's initWithRootViewController message, then after that line, it will have a retain count of two (I am pretty sure UINavigationController will retain it's root view controller).

Adding the navController's view to the window will not affect the rootController's retain count (It will increment the retain count on the UIView member of navController).

After the rootController release, it will decrement the retain count down to one.

Edit

Yep. In fact you could simplify the code a little more by removing the release at the bottom and sticking an autorelease around the initial allocation.

Answer 2

initWithRootViewController: retains navController. And addSubview: retains navController.view

EDIT: Yes, that is true. And [rootController release] does not actually release rootController, it just decrements its retain count by one since it is already retained by initWithRootViewController.