Another CoreAnimation Protip
If you’re building your interface using CALayers, beware the following weirdness when sublayers are added to a parent layer. I had a parent layer, with a bunch of sublayers being added and removed during the lifetime of the view. I didn’t want any animations when that occurs, but I was still noticing a fade in / fade out action going on.
I had already disabled the kCAOrderIn and kCAOrderOut action keys on the sublayers, but I didn’t realize I also had to disable the sublayers action on the parent layer. Beware that the sublayers action is also fired when you call [CALayer addSublayer:] and [CALayer removeFromSuperlayer].