Question

I’ve got a scrollView app. And each scrollView item has it’s own title (navigationItem title). Now when user does something(I have a way of capturing this event) on a particular scrollView item I want to animate the navigation item.

I was thinking maybe changing it’s background color continuously or something or maybe better increase/decrease it’s transparency if possible.

Has anyone done something similar to this? What would be the right approach to do this? I don’t have a script requirement what I need to do, just that the current scrollView item(view) is different from others.

Thanks for any suggestions

I got it from the response I received :

CABasicAnimation *animation=[CABasicAnimation animationWithKeyPath:@"opacity"];
    animation.duration=1.5;
    animation.repeatCount=1000000;
    animation.autoreverses=YES;
    animation.fromValue=[NSNumber numberWithFloat:1.0];
    animation.toValue=[NSNumber numberWithFloat:0.3];
    [button addAnimation:animation forKey:@"animateOpacity"];

it’s not too fast and intensive to cause a seizure I hope

Answer 1

UIBarButtonItem (annoyingly) does not inherit from UIView, so CoreAnimation would do diddly squat if you tried it. However, if you rolled your own navigation item with a UIButton and a UIImageView set as the customView property, then animation is entirely possible with UIView’s block animation wrapper:

[UIView animateWithDuration:1.0f animations:^{
    [myButton setAlpha:0.0f];
    //the button is now invisible
}];

As for color animations, unfortunately, only CGColors may be animated, and then, only under very sketchy circumstances.