Determining Whether Current Animation Has Been Completed

Question

For the iPhone, I want to combine two animations together but am crossing some problems. Basically, I want to hide and then show some outlets in one go. I can do this when they are separated into different events, but I when I combine them, the second round of animations (the show portion) takes precedence (when setAnimationBeginsFromCurrentState:FALSE). When it is setAnimationBeginsFromCurrentState:TRUE, nothing really happens at all.
Is there some way that I can have it wait till all the hiding stuff and then do the show stuff? I suppose this defeats the purpose of core animation's implicit purpose, so I guess I'm trying to go for a keyframe type of approach (I'm not sure. I'm pretty new to objective-c).
// The following chunk is set on awakeFromNib
zero = CGPointMake(250.0f, 524.0f);
bCenter01 = [button01 center];
bCenter02 = [button02 center];
//here are just the first two of my buttons that I wan't to animate, but imagine 14 more after this
// END awakeFromNib chunk
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// assume this is a button press
// HIDE portion
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:FALSE];
float time = 1.7;
CGAffineTransform rotate = CGAffineTransformMakeRotation(-M_PI);
[UIView setAnimationDuration:time];
[button01 setCenter:zero];
[button01 setTransform:rotate];
[button01 setAlpha:0.0];
time -= .1;
[UIView setAnimationDuration:time];
[button02 setCenter:zero];
[button02 setTransform:rotate];
[button02 setAlpha:0.0];
time -= .1;
// again, assume this is repeated 14 more times for the other buttons
// SHOW portion (this is basically where I want the animation to start after the HIDE has finished
// currently, when the button is pressed, the animation currently just starts from here (as it has "instantly" moved everything from the hide portion)
time = 0.2;
[UIView setAnimationDuration:time];
[button01 setTransform:rotate];
[button01 setCenter:bCenter01];
[button01 setAlpha:1.0];
time += .1;
[UIView setAnimationDuration:time];
[button02 setTransform:rotate];
[button02 setCenter:bCenter02];
[button02 setAlpha:1.0];
time += .1;
// again, assume 14 more...
[UIView commitAnimations];

Answer 1

I figured out how to do this. If anyone wants to know how to perform an animation after another one, this is what I did...
By the way, you don't have to declare the goPutThemBack in your header file.
- (IBAction)clear:(id)sender {
[UIView beginAnimations:nil context:NULL]
[button01 setCenter:offWindow];
// all your animations up here for the first part (let's assume this will hide something)
// now the magic to starting the second part
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:@selector(goPutThemBack:finished:context:)];
// end magic part
[UIView commitAnimations];
- (void)goPutThemBack:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context {
[UIView beginAnimations:nil context:NULL];
[button01 setCenter:onWindow];
// second set of animations
[UIView commitAnimations];