CALayer addAnimation:forKey: animates every property set before

Question

So, I've got a CALayer from a UITableView instance. I first want to set a couple properties like the backgroundColor. Afterwards I add an animation that is supposed to make the reloading (-reloadData) look nicer. However, the CATransition I'm adding also animates the backgroundColor I set before. I guess I'm missing something real basic here but I really don't get what.

Here's my code:

    self.superview.backgroundColor = [UIColor greenColor];
    self.backgroundColor = nil;
    self.backgroundView.backgroundColor = nil;

I want the UITableView to be green immediately.

Here's the transition:

CATransition* swapAnimation = [CATransition animation];
            swapAnimation.type = kCATransitionPush;
            swapAnimation.subtype = kCATransitionTypeFromUITableViewRowAnimation(animation);
            swapAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
            swapAnimation.fillMode = kCAFillModeBoth;
            swapAnimation.duration = 5.0f;
            swapAnimation.removedOnCompletion = YES;
            [self.layer addAnimation:swapAnimation forKey:@"UITableViewReloadDataAnimationKey"];

When I'm running this, the UITableView keeps its original backgroundColor, the green (which is actually shining through the now transparent UITableView) slides in from the top/bottom with the cells. It's code from a category explaining the self.layer calls.

Answer 1

Looks like you need to wrap the background color setter in an explicit CATransaction, because it's not getting flushed until after you add the animation.

Like so:

[CATransaction begin];
// set background
[CATransaction flush];
[CATransaction commit];