Question

I have an implict animation as follows:

[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1];
[UIView setAnimationDelegate:self];

...

[UIView commitAnimations];

When this animation begins and ends, it triggers these delegate functions:

- (void)animationWillStart:(NSString *)animationID context:(void *)context;

- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag;

I have multiple things that get animated in my viewController, and the delegate functions are getting crossed. How do I tag a particular animation so I can check which one it is in the delegate functions?

It’s also odd to me that the parameter for one of these functions is a string while the other is a CAAnimation. Both of these methods get called, but am I using the wrong one or something?

Answer 1

For implicit animations like that, you set your animationDidStopSelector:

[UIView setAnimationDidStopSelector:@selector(animationDidEnd:finished:context:)];

and that will call your animationDidEnd as follows:

- (void) animationDidEnd:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context

This is pretty much the same as the animationWillStartSelecter which calls beginAnimations:context:

For both, you can use context to pass in a tag or other values that your selectors can use to distinguish the animation.