UINavigationBar change Tint color with animation

Question

Is it possible to change the tint with animation for a smoother effect?

This doesn't work for me:

[UIView beginAnimations:nil context:nil];
[self.navigationController.navigationBar setTintColor:[UIColor greenColor]];
[UIView commitAnimations];

I a not sure if it is even possible using native apple components as I guess they will be using CG to generate the gradient ... just want to find out before I'll start building my own solution ...

Cheers guys :)

Answer 1

You wouldn't believe the length I went through to actually make that possible; it annoyed me to no end that this isn't a stock iOS feature and that transition of tintColor look ugly while the animation to push/pop a viewController is so smooth.

There'a lot of code that checks when to fade, and I've even written a class called PSPDFNavigationAppearanceSnapshot to preserve the navigation state when being popped. (I got that idea from the awesome NimbusKit)

The actual animation is pretty easy:

[self.navigationController.navigationBar.layer addAnimation:PSPDFFadeTransition() forKey:nil];

CATransition *PSPDFFadeTransition(void) {
    return PSPDFFadeTransitionWithDuration(0.25f);
}

CATransition *PSPDFFadeTransitionWithDuration(CGFloat duration) {
    CATransition *transition = [CATransition animation];
    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    transition.type = kCATransitionFade;
    transition.duration = duration;
    return transition;
}

You can compact that code even more; it's a snipped from my iOS PDF library PSPDFKit and I use the fade in various places, thus the helper functions.