A means to display additional content related to existing content on the screen.
- macOS 10.7+
The popover is positioned relative to the existing content and an anchor is used to express the relation between these two units of content. A popover has an appearance that specifies its visual characteristics, as well as a behavior that determines which user interactions will cause the popover to close. A transient popover is closed in response to most user interactions, whereas a semi-transient popover is closed when the user interacts with the window containing the popover's positioning view. Popovers with application-defined behavior are not usually closed on the developer's behalf.
The system automatically positions each popover relative to its positioning view and moves the popover whenever its positioning view moves. A positioning rectangle within the positioning view can be specified for additional granularity.
Popovers can be detached to become a separate window when they are dragged by implementing the appropriate delegate method.