How do I find details of the current UIView animation?

Question

I have a setter method for a property on a custom UIView class. If it's set within a UIView animation block, I'd like it to add a CABasicAnimation to the view's layer with the same duration and easing as the UIView animation. How do I find out whether I'm inside a UIView animation block, and how do I get its duration and easing curve?

Answer 1

Based on this question I made this extension to UIView block animations: UIView+AnimatedProperty.

It allows you to run CAAnimations when the setter is called from animation block. Example with cornerRadius is included.

Answer 2

Very simple.. You can get all animation keys applied to your view using

[self.YourView.layer animationKeys];

Answer 3

You can get the current animation easily enough. For instance, setting up a CATransaction:

CAAnimation *animation = [self.layer animationForKey:self.layer.animationKeys.firstObject];
[CATransaction begin];
[CATransaction setAnimationDuration:animation.duration];
[CATransaction setAnimationTimingFunction:animation.timingFunction];

// CALayer animation here

[CATransaction commit];

Answer 4

The documentation for [UIView animateWithDuration] states that

This method performs the specified animations immediately using the UIViewAnimationOptionCurveEaseInOut and UIViewAnimationOptionTransitionNone animation options.

As for the duration, you set the duration yourself, so you already now that.