On May 30, 2009, at 5:43 PM, Pierre Berloquin wrote:
Declaring in .h
-(void)vagTouchesBegan:(id)sender;
was my first impulse. But that's not enough.
It's not clear from your two posts which method you're getting a
warning for. I thought it was for the -vagTouchesBegan method, but you
claim it's not. Please post the actual warning that you get from XCode.
About the memory problem, I suppose I should receive touchesBegan in
the
controller and sort out what I get ?
No, that's not what I was referring to. I was referring to the fact
that if an object of class A retains an object of class B and that
same object of class B also retains the object of class A which
retains it, then you have what's called a retain cycle. That may cause
you trouble if you're not careful.
The view controller already retains its view, so if you're passing the
view controller object to the view object for it to keep, then the
view object should NOT retain that view controller object. If what I
just said isn't completely clear to you, you should read
http://devworld.apple.com/documentation/Cocoa/Conceptual/MemoryMgmt/MemoryMgmt.html
If that document is still a bit obscure, then you should search the
web for more accessible explanations. For instance,
http://stackoverflow.com/questions/791322/retain-cycles-why-is-that-such-a-bad-thing
Note that it *is* ok for the view object to have a pointer to its view
controller. All I'm saying is that you should avoid retaining the view
controller in its view. Thus, instead of
- (void) setViewController: (UIViewController*) vcontroller
{
[viewController release];
viewController = [vcontroller retain];
}
(which is the typical setter for objects) you should have
- (void) setViewController: (UIViewController*) vcontroller
{
viewController = vcontroller; // Note: no release and no retain
}
(atypical for objects, but necessary in this case to avoid a retain
cycle).
Or, if you prefer to use properties, instead of
@property (readwrite, nonatomic, retain) UIViewController*
viewController;
you should use
@property (readwrite, nonatomic, assign) UIViewController*
viewController;
Wagner
2009/5/30 WT <jrca...@gmail.com>
On May 30, 2009, at 4:40 PM, Pierre Berloquin wrote:
[theViewController vagTouchesBegan:self];
QED
There's still a warning that the view controller may not respond.
But it
works seamlessly.
Can I get rid of the warning?
Yes, by declaring the method -vagTouchesBegan: in the header file
of your
view controller class.
Something to be cautious about when storing in the view a pointer
to its
view controller is that you may end up creating a retain cycle,
since the
view controller already retains its view. I would recommend that
you read
the documentation on memory management to make sure you don't create
unnecessary problems for yourself.
Wagner
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