A uisplitviewdelegate is actually a UISplitViewControllerDelegate, which defines methods that allow you to manage changes to a split view interface.
From the docs:
A uisplitviewdelegate is actually a UISplitViewControllerDelegate, which defines methods that allow you to manage changes to a split view interface. Use the methods of this protocol to respond to changes in the current display mode and to the current interface orientation. When the split view interface collapses and expands, or when a new view controller is added to the interface, you can also use these methods to configure the child view controllers appropriately.
