Rotate UIView around its center keeping its size

Question

I'm trying to rotate an UIView a few radians but after applying the transformation it doesn't look to be keeping its size. What's the proper way to achieve this?

Here's what I'm doing and what I get (Blue box with the arrow is the View I'm trying to rotate -- it should keep same aspect as red box behind):

#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)

double rads = DEGREES_TO_RADIANS(240);
CGAffineTransform transform = CGAffineTransformRotate(CGAffineTransformIdentity, rads);
self.arrowView.transform = transform;

Thanks!

Answer 1

The CGAffineTransformRotate transformation rotates from an existing affine transform. The fact that you are using CGAffineTransformIdentity might be the issue. You must specify the current transform of your view.

#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)
...
double rads = DEGREES_TO_RADIANS(240);
CGAffineTransform transform = CGAffineTransformRotate(self.arrowView.transform, rads);
self.arrowView.transform = transform;

Also, you might want to consider:

self.arrowView.transform = CGAffineTransformMakeRotation(rads);

EDIT : If you can, share what you kind of transformation (animated/inanimate , single/iterative) you want to achieve. I believe there might be a better, optimized way of doing this.

Answer 2

Try with this code:

#define DEGREES_TO_RADIANS(angle) ((angle) / 180.0 * M_PI)

double rads = DEGREES_TO_RADIANS(240);
self.arrowView.layer.transform = CATransform3DMakeRotation(rads, 0, 0, 1);