Constants describing the possible display modes for a split view controller.
Display modes apply to a split view controller in an expanded arrangement. When the split view interface is collapsed, the display mode is ignored.
The split view controller automatically decides the most appropriate display mode based on the device and the current app size. You can assign this constant as the value of the
preferredDisplayMode property but this value is never reported by the
The primary and secondary view controllers are displayed side-by-side onscreen.
The primary view controller is layered on top of the secondary view controller, leaving the secondary view controller partially visible.