It seems the image size related stuff should work perfectly but I'd pass an UIImage object to the initWithImage method.

Kimitri commented on Objective-C / iPhone coding question: How to read pixel width&height of an image (written by Ile) 04.10.2010 (en) posted to #programming

I know very little Objective-C but I'd say the traditional way is to use a delegate. However, the whole Grand Central Dispatch + CoreData + llvm + clang thingy pushed Apple to add closures to Objective-C. So, I guess you could use closures if you're targeting new OS X instances.

Kimitri commented on How to implement callbacks in objective-c? (written by Ile) 03.06.2010 (en) posted to #programming