Parmanoir

While looping over a collection and adding a CALayer for each object, you won't see any refresh during the loop : you'll beachball until you've run through your collection, and then your view will update. But as Core Animation is threaded, it's only a matter of saying "I want an update just now".

Use [CATransaction commit] to have your NSView update instantly.

If you're animating your CALayer

• create your CALayer
• flush it to the screen with [CATransaction commit]
• setup an animation like layer.transform = CATransform3DMakeRotation(1.57, 0, 0, 1)
• flush it again, still with [CATransaction commit]

There you go ! That's an easy way to do some work over lots of objects while updating your NSView easily, without having to worry about threads.