Collision when bounds of a view are changing

Question

I am working with UIDynamicAnimator, UICollisionBehavior and several moving UIImageView. It looks like this when everything is working fine. Pictures are moving on the screen without superposition.

But after I changed the bounds of some views, the collision doesn't update as it should and it gives me this:

The collision doesn't work anymore as expected: views became superposed.

I am updating the bounds with this code:

    [UIView animateWithDuration:2
                      delay:0
                    options:UIViewAnimationOptionCurveEaseInOut
                 animations:^{
                     CGRect newBounds = imageView.bounds;
                     newBounds.size.height = 500;
                     newBounds.size.width = 500;
                     imageView.bounds = newBounds;
                 }
                 completion:^(BOOL finished) {
                     [animator updateItemUsingCurrentState:imageView];
                 }];

updateItemUsingCurrentState: function doesn't seem to have effect on bounds changes... Am I right?

Answer 1

I succeed to do it by setting my animator variable to nil and declaring it and every linked animation behaviors again.

If someone else has a better way to do it, I am still listening. Thanks.

Answer 2

I ended up removing all behaviors from the dynamic animator without deallocing it and re-adding them again:

        let behaviors = (self.dynamicAnimator.behaviors as NSArray).copy() as! [UIDynamicBehavior]
        self.dynamicAnimator.removeAllBehaviors()
        for behavior in behaviors {
            self.dynamicAnimator.addBehavior(behavior)
        }