Re: [NSView removeFromSuperview] not affecting retain count

FROM : Julian Pellico
DATE : Mon Dec 20 20:04:30 2004

> Why do you check this in the first place? Do you suspect that there is
> a leak? What made you suspicious of that? Have you tracked it with
> ObjectAlloc?

Of course; otherwise I wouldn't be printing out retain counts. I do
exactly these things with the MyView:
- allocate a MyViewController which contains a MyView
- add the MyViewController to an array
- release the MyViewController
- make the MyView a subview of another custom view
- call removeFromSuperview on the MyView
- remove the MyViewController from the array

The MyViewController gets dealloc'ed, but the MyView doesn't.

>
> What if you write that method like this:
>
> - (void) removeMyViews
> {
>        for (int i = 0; i < [myViewControllers count]; i++)
>        {
>                NSView *aView = [[myViewControllers objectAtIndex: i] view];
>                NSLog(@"--- 1 --- %@ retainCount: %u, superview: %@", aView, [aView
> retainCount], [aView superview]);
>                [aView removeFromSuperview];
>                NSLog(@"--- 2 --- retainCount: %u, superview: %@", [aView
> retainCount], [aView superview]);
>        }
>        [myViewControllers removeAllObjects];
> }
>
> Does it make any difference if you replace "removeFromSuperview" with
> "removeFromSuperviewWithoutNeedingDisplay"?

I forgot to try these things when I was at home -- I'll do this tonight.

> My advice is always that you shouldn't try to track retain count like
> that. What if it's autoreleased?

It would hardly be safe for the frameworks to autorelease it. I might
want that NSView well past the end of the run loop.