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I am trying to make UIView glow back and forth twice. My animation below works but just after it has finished it goes to the state that I animated it to, and not the original. I set autoreverses to YES so why is it not going back to original state ?

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationRepeatCount:2];
[UIView setAnimationRepeatAutoreverses:YES];
[UIView setAnimationDuration:0.3];
[UIView setAnimationBeginsFromCurrentState:YES];
textDetailView.layer.backgroundColor = [UIColor colorWithRed:0 green:1 blue:0 alpha:0.3].CGColor;
[UIView commitAnimations];
pnizzle
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1 Answers1

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The animation reverses but the value doesn't. After the animation completes it removes itself from the view (actually from the views layer) and the view appears to have the properties that have been set on it.

You could set the value back in a completion block or in the selector for the older UIView animation that you are using.

Alternatively, for animations where the value doesn't change you could benefit from using Core Animation (which doesn't hangs the value (after the animation the view goes bak to its original state)).

You would need to import QuartzCore.framework and include QuartzCore/QuartzCore.h to get it to work.

The could would also need to be updated to something like this: 

CABasicAnimation *myColorAnimation = [CABasicAnimation animationWithKeyPath:@"backgroundColor"];
[myColorAnimation setAutoreverses:YES];
[myColorAnimation setRepeatCount:2];
[myColorAnimation setDuration:0.3];
[myColorAnimation setToValue:(id)[myColor CGColor]];
// the default "from value" is the current value
[[textDetailView layer] addAnimation:myColorAnimation forKey:@"myColorKey"];
David Rönnqvist
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  • I was using CABasicAnimation until I realised I need to use the "didFinishSelector" to do something after my animation finishes. Since I am forced to go back to that, how do I get a signal that my CABasicAnimation has finished ? Is there some sort of delegate method. Thanks – pnizzle Jun 18 '12 at 10:45
  • @pnizzle In this specific case you _don't_ need the callback since the view will have the original color after the animation, just like you wanted it to. That's why it's a good fit for your case. – David Rönnqvist Jun 18 '12 at 10:51
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    @pnizzle Yes, you can set yourself as the `delegate` of the animation and then you will get callbacks for `animationDidStart:` and `animationDidStop:finished:` – David Rönnqvist Jun 18 '12 at 10:52
  • thanks for the quick reply. I meant to say that when the animation finishes (glows twice and goes back to normal state), some method should be called which will do some other animation. I wanted to call this method in the @selector(methodName). I need to find a way to detect that the animation has finished or stopped so my next animation can be called – pnizzle Jun 18 '12 at 10:56
  • Just saw your second comment, let me implement these and let you know how it goes. Thanks – pnizzle Jun 18 '12 at 10:57
  • thanks for the animationDidFinish: it took me to an interesting discussion on [identifying CAAnimation within animationDidFinish](http://stackoverflow.com/questions/1255086/how-to-identify-caanimation-within-the-animationdidstop-delegate) as I found out it is not so simple to do so – pnizzle Jun 18 '12 at 23:39