On iPhones:
- It will force the full width of the accessory view irrespective of its content
- Placing a view that manages its own glass – like a collection of individual glassy buttons – means that the full-width container is still encased in an outer layer of glass.
- There is no way to remove the outer glass layer, and it's not exposed as a property of a visual effect view, of the parent
_UITabAccessoryContainer, or its parent_UITabBarContainerView.
On iPads:
- Infuriatingly, it behaves completely different in regular width layouts.
- Suddenly, it doesn't draw a full width glass container around the content and starts respecting the supplied view's layout. A collection of glassy buttons starts working as intended.
- This all falls apart in compact layouts and starts behaving like an iPhone.
The lack of configuration on this API is deeply unusual. More unusual is that there's no layout guide or similar for us to hook into to supply our own bottom accessory behavior.