How to automatically resize NSPopover with auto-layout

Question

I currently have a subclass of NSPopover that sets it by the content controller to a custom NSViewController designed to represent tabs:

self.popover.contentViewController = tabViewController; self.popover.animates = YES; 

I run my own “tab view controller” because I heard that the NSTabViewController doesn’t play the animation well. I would like to use auto-layout, so I don't think I want to combine with the popover contentSize property. When I change tabs, popover resizes correctly, however it doesn’t bring changes to life. In addition, I have a crossfade animation that occurs when the tab switch is switched and the popover does not change until the animation ends.

First, I would like to figure out how to get a resized popover for an animation, and then I will worry about synchronizing the animation.

thanks