IPhone SDK - how can I find out when the animation is over?

Question

I start the animated extension when I touch the image, and then reduce it to its normal size when it is released. With setAnimationBeginsFromCurrentState: YES, the zoom effect is nice and smooth if you lift part of your finger through the animation.

However, what I want to do is to “lock” the larger size in place if you touch the image long enough to complete the animation, but let it shrink as usual if you release it prematurely.

Is there a way to find out if there is an animation at the moment, or is a specific animation completed?

I suppose I can possibly do this with the performSelector: afterDelay: call in touchesStarted function, with a delay equal to the length of the animation and cancel it if touchEEnd arrives too soon, but I can’t imagine that this is the best way ...

Answer 1

- (void)animateStuff {
    [UIView beginAnimations:@"animationName" context:nil];
    [UIView setAnimationDelegate:self];
    [self.view doWhatever];
    [UIView commitAnimations];
}

- (void)animationDidStop:(NSString *)animationID
                finished:(NSNumber *)finished
                 context:(void *)context
{
    if ([finished boolValue]) {
        NSLog(@"Animation Done!");
    }
}

Answer 2

Another possibility:

 [UIView animateWithDuration:0.3 animations:^{

      myView.transform = CGAffineTransformMakeRotation(M_PI);

 }completion:^(BOOL finished) {

      NSLog(@"Animation complete!");
 }];

Answer 3

I think the "+ (void) setAnimationDidStopSelector: (SEL) selector" should do what you want. It will call this selector in your delegate after the animation is complete.