Popovers and split views are forms of interface designed originally for the iPad. In iOS 7 and before, they existed only on the iPad. New in iOS 8, both are available also on the iPhone, where they can either adapt — appearing in an altered form, more appropriate to the smaller screen — or appear just as they do on the iPad.
A popover is a sort of secondary window or dialog: it displays a view layered on top of the main interface. It is usually associated, through a sort of arrow, with a view in the main interface — usually the button that the user tapped to summon the popover. The popover dims out the rest of the screen, like a
.FormSheet presented view (see Chapter 6). It might be effectively modal, preventing the user from working in the rest of the interface; alternatively, it might vanish if the user taps outside it.
A popover can bring to the larger iPad the smaller, more lightweight flavor of the iPhone. For example, in my LinkSame app, both the settings view (where the user configures the game) and the help view (which describes how to play the game) are popovers (Figure 9-1). On the iPhone, both these views would occupy the entire screen; for each, we’d need a way to navigate to it, and then the user would have to return to the main interface afterward. But with the larger iPad screen, neither view is large enough, or important enough, to occupy the entire screen exclusively. As popovers, they are characterized as smaller, secondary ...