CALayer with rotation animation

Question

I have masked an image like this:

UIView *maskImage; maskImage = [[UIView alloc] init];
maskImage.backgroundColor = UIColorFromRGB(FTRMaskColor);
maskImage.frame = newFrame;

CALayer *theLayer = [CALayer layer];
theLayer.contents = (id)[[UIImage imageNamed:@"image.png"] CGImage];
theLayer.frame = newFrame;

maskImage.layer.mask = theLayer;

It works fine but the main problem is if I want to rotate the my Ipad, the rotation animation of the view or the layer (I'm not very sure) doesn't work. It rotates without animation. Could you help, please?

Answer 1

To rotate a CALayer:

NSNumber *rotationAtStart = [myLayer valueForKeyPath:@"transform.rotation"];
CATransform3D myRotationTransform = CATransform3DRotate(myLayer.transform, myRotationAngle, 0.0, 0.0, 1.0);
myLayer.transform = myRotationTransform;        
CABasicAnimation *myAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
myAnimation.duration = kMyAnimationDuration;
myAnimation.fromValue = rotationAtStart;
myAnimation.toValue = [NSNumber numberWithFloat:([rotationAtStart floatValue] + myRotationAngle)];
[myLayer addAnimation:myAnimation forKey:@"transform.rotation"];

myRotationAngle should be in radians. Use negative values for counter-clockwise rotation and positive values for clockwise.