Top level interfaces and dialogs can be manipulated by the user, such as being iconifed or maximized. The program can manipulate these windows too. The function
top-level-interface-display-state returns a value that indicates the current state of the interface
. The following values can be returned:
The window is visible and has its normal size.
The window is visible and has been maximized.
The window is visible as an icon.
The window is not visible.
In addition, the function
(setf top-level-interface-display-state) can be used to change the state of a top level interface. The value can be set to one of the above, or to
:restore if the current state is
:hidden. When set to
:restore, the state will become
:maximized depending on how the interface was visible in the past.
CAPI User Guide and Reference Manual (Macintosh version) - 3 Aug 2017