CATransaction kCATransactionCompletionBlock or similar delegate on iPhone?

Question

I am animating an arbitrary number of layers simultaneously using a CATransaction on the iPhone and would like to be able to perform some additional functionality when the transaction completes. I get animationDidStop calls for each layer that gets animated in the transaction, but would like to know when all layers are done – which would be when the transaction completes. I don't see a similar delegate within CATransaction that would provide notification when the transaction completes, and short of rolling my own notification based on tracking the arbitrary number of layers animating in a given transaction and decrementing that count each time animationDidStop gets called, I'm not sure how to hook into the end of the transaction.
Looking in the docs, I see 2 versions of CATransaction in the class reference, one for iPhone OS 2.0 and later, and one for Mac OS X 10.5 and later. The Mac OS version mentions a completionBlock object accessible via the kCATransactionCompletionBlock property available in Mac OS X 10.6 and later, which doesn't appear to be available for the iPhone?
Does anyone know if the completionBlock property is available on the iPhone or if there is a completion delegate or similar mechanism for receiving notification of a CATransaction completing?
Thanks in advance for any help or suggestions.

Answer 1

JavaJoe23 wrote:
Does anyone know if the completionBlock property is available on the iPhone
Have you tried using the name of the property instead of the constant? E.g.:
[CATransaction valueForKey:@"completionBlock"];
The docs are inconsistent about this. I don't know the story yet, but here's what I'm seeing:
1) Check out the DocumentRevisionHistory in this pdf: [http://developer.apple.com/Mac/library/documentation/GraphicsImaging/Reference /CATransactionclass/CATransactionclass.pdf]
2009-06-01
Updated for iPhone OS 3.0. Added new convenience methods, methods for locking, overriding timing functions, and completion blocks.
2) On my system, /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.1.sdk/System/Li brary/Frameworks/QuartzCore.framework/Headers/CATransaction.h includes this comment:
* Currently supported transaction properties include:
* "animationDuration", "animationTimingFunction", "completionBlock",
* "disableActions". See method declarations above for descriptions of
* each property.
But when I add the QuartzCore framework to my Device 3.1 project, the Groups & Files tree tells me I have a different framework with a header that doesn't include the above comment: /System/Library/Frameworks/QuartzCore.framework/Versions/A/Headers/CATransactio n.h
I haven't gotten any farther than the above observations to date. Every time I've tried to second guess Xcode the adventure has ended badly, so I haven't gone there yet. But maybe the above clues will be useful to you.
- Ray