NSLayoutConstraint.constant ignoring animation

Question

I\'m creating an autolayout-friendly split view class for one of my applications. Among its various features is that it can collapse panes, and can animate their collapse, much

Answer 1

I agree, this is pretty strange, and could well be a bug. I'd definitely report it as such because, to the best of my knowledge, this should work.

I was able to get it to work by using the NSAnimationContext class method +runAnimationGroup:completionHandler: instead of the beginGrouping and endGrouping statements:

[NSAnimationContext runAnimationGroup:^(NSAnimationContext* context){
    [constraint.animator setConstant:self.width];   
} completionHandler:^(void){
    [theView removeConstraint:constraint];
    NSLog(@"completed");
}];