How do I chain scale animations with an iPhone UIImageView?

Question

I'm trying to scale an image down, change the image, then scale it back up.

CABasicAnimation* shrink = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
shrink.toValue = [NSNumber numberWithDouble:0];
shrink.duration = 1;
    shrink.delegate = self;
    [myImageView.layer addAnimation:shrink forKey:@"shrink"];   

makes the shrink, then when it completes, I change the image, and start the grow:

- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag 
{
    myImageView.image = [images objectAtIndex:image];
CABasicAnimation* grow = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
grow.toValue = CGAffineTransformMakeScale(1,1);
    grow.delegate = self;
grow.duration = 1;
[myImageView.layer addAnimation:grow forKey:@"grow"];   
}

This works great on the simulator, but on the device, when the shrink completes, I get a flash of the full-size, old image, then the grow animation begins with the new image.

Any idea how to get rid of that flash?

(I've tried "removedOnCompletion = NO;" and attempted setting the affineTransform equal to the scaled down size after the first completion, but didn't have much luck.)

Any tips appreciated.

kb

Edit:

Excellent! Setting the following:

shrink.fillMode = kCAFillModeForwards; 
shrink.removedOnCompletion = NO; 

Removed the flashing. Thanks, Ben!

Answer 1

Try setting your animation's fillMode to kCAFillModeForwards. That should leave the item as it was at the end of the animation, rather than before.

Answer 2

I've had the same problem when I tried to create another CAAnimation in the animationDidStop method. I suggest using CAKeyframeAnimation.