A popover is a transient view that appears above other content onscreen when you tap a control or in an area. Typically, a popover includes an arrow pointing to the location from which it emerged. Popovers can be nonmodal or modal. A nonmodal popover is dismissed by tapping another part of the screen or a button on the popover. A modal popover is dismissed by tapping a Cancel or other button on the popover.
Popovers are most appropriate on larger screens and can contain any variety of elements, including navigation bars, toolbars, tab bars, tables, collections, images, maps, and custom views. When a popover is visible, interactions with other views are normally disabled until the popover is dismissed. Use a popover to show options or information related to the content onscreen. Many iPad apps, for example, show a popover of sharing options when you tap the Share button.
Avoid displaying popovers on iPhones. Generally, popovers should be reserved for use in iPad apps. In iPhone apps, utilize all available screen space by presenting information in a fullscreen modal view, rather than in a popover. For related guidance, see Modality.
Use a Close button for confirmation and guidance only. A Close button, such as Cancel or Done, is worth including if it provides clarity, such as exiting with or without saving changes. In general, a popover should close automatically when its presence is no longer necessary. In most cases, a popover should close when someone taps outside of its bounds or selects an item in the popover. If multiple selections can be made, the popover should remain open until someone explicitly dismisses it or taps outside of its bounds.
Always save work when automatically closing a nonmodal popover. It’s easy to dismiss a nonmodal popover unintentionally by tapping another part of the screen. Discard work only when someone taps an explicit Cancel button.
Position popovers appropriately onscreen. A popover’s arrow should point as directly as possible to the element that revealed it. Because popovers can’t be dragged around the screen, a popover shouldn’t cover essential content people may need to see while using the popover. A popover also shouldn’t cover the element that was tapped to show the popover.
Show one popover at a time. Displaying multiple popovers clutters the interface and causes confusion. Never show a cascade or hierarchy of popovers, in which one emerges from another. If you need to show a new popover, close the open one first.
Don’t show another view over a popover. Except for an alert, nothing should be displayed on top of a popover.
When possible, let users close one popover and open another with a single tap. Avoiding extra taps is especially desirable when several different bar buttons each open a popover.
Avoid making a popover too big. A popover shouldn’t take over the entire screen. Make it only big enough to display its contents and point to the place it came from. Be aware that the system might adjust the size of a popover to ensure it fits well onscreen.
Make sure custom popovers look like popovers. Although you can customize many of the visual aspects of a popover, avoid creating a design people might not recognize as a popover. Popovers tend to work best when they contain standard controls and views.
Provide a smooth transition when changing the size of a popover. Some popovers provide both condensed and expanded views of the same information. If you adjust the size of a popover, animate the change to avoid giving the impression that a new popover replaced the old one.
For developer guidance, see UIPopoverPresentationController.