Is there any way to create a custom animation for NSPopover?
I can switch off the animation by using the animates property, however since NSPopover is a subclass of NSResponder and not a proper view or window I can't figure out how to animate it myself.
There is no way to hook into the animation system of NSPopover. I did a class-dump of the interface and it doesn't even look like there are any useful private methods.
If you want a custom animated popover you will need to implement it from scratch (which is not that hard, really).