rotate a UIView around its center but several times

Question

I\'m trying to rotate some UIView around its center, so the simple code goes something like (in pseudocode):

[UIView beginAnimations:@\"crazyRo         


        

Answer 1

As Brad Larson indicated, you can do this with a CAKeyframeAnimation. For instance,

CAKeyframeAnimation *rotationAnimation;
rotationAnimation = 
   [CAKeyframeAnimation animationWithKeyPath:@"transform.rotation.z"];

rotationAnimation.values = [NSArray arrayWithObjects:
                            [NSNumber numberWithFloat:0.0 * M_PI], 
                            [NSNumber numberWithFloat:0.75 * M_PI], 
                            [NSNumber numberWithFloat:1.5 * M_PI], 
                            [NSNumber numberWithFloat:2.0 * M_PI], nil]; 
rotationAnimation.calculationMode = kCAAnimationPaced;
rotationAnimation.removedOnCompletion = NO;
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.timingFunction = 
   [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
rotationAnimation.duration = 10.0;

CALayer *layer = [viewToSpin layer];
[layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];

You can control the duration of the total animation with the rotationAnimation.duration property, and the acceleration and deceleration (and calculation of steps in between) with the rotationAnimation.timingFunction property.