How is retain setter implemented with @synthesize?

Question

I have the following in the header:

@property (nonatomic, retain) UIView *overlay;

And in the implementation:

@synthesize o         


        

Answer 1

A synthesized retained setter looks like :

- (void)setValue: (id)newValue
{
    if (value != newValue)
    {
        [value release];
        value = newValue;
        [value retain];
    }
}

In your case, you have two valid methods :

1) Create a temp var, alloc/init (= retained), set to property, release.

IView *tempOverlay = [[UIView alloc] initWithFrame:CGRectMake(160.0f, 70.0f, 150.0f, 310.0f)];
self.overlay = tempOverlay;
[tempOverlay release];

2) No temp var, set directly to ivar.

overlay = [[UIView alloc] initWithFrame:CGRectMake(160.0f, 70.0f, 150.0f, 310.0f)];

UPDATE: If you use method 2), you have to explicitly handle the rest of memory management (not only retaining), by releasing any previous value it might have before if needed. If done only once in init (for instance), you can just put a [overlay release]; in dealloc.