Open Radar

 
Summary:
In the Calendar and Safari apps on iOS, their navigation controllers display content below the title and buttons, and automatically animate between view controller pushes, or can be pinned while the title and bar button items change. A public API for this would be best because current solutions are far from perfect. Using container views, the navigation bar blurs do not match from the parent controller and child controller. Subclassing UINavigationBar to extend the content slightly works, but the bar button items either get centered or moved to the bottom, and the content of the view controller scroll view does not automatically set its insets to the custom height. It also does not allow for pinning the content between view controllers, and could break easily with iOS updates.

Steps to Reproduce:
NA

Expected Results:
Able to set a "contentView" on UINavigationController which will be pinned in place between view controller pushes. If a view controller sets a content view for itself, it will animate with the push to the new content view and height.

Actual Results:
Not currently possible without creating a custom navigation bar, bar items, and layout or subclassing UINavigationBar which can break with iOS updates.