Function: display-save-under
display-save-under is a byte-compiled function defined in frame.el.gz.
Signature
(display-save-under &optional DISPLAY)
Documentation
Return non-nil if DISPLAY's screen supports the SaveUnder feature.
DISPLAY can be a display name or a frame. If DISPLAY is omitted or nil, it defaults to the selected frame's display.
Probably introduced at or before Emacs version 21.1.
Source Code
;; Defined in /usr/src/emacs/lisp/frame.el.gz
(defun display-save-under (&optional display)
"Return non-nil if DISPLAY's screen supports the SaveUnder feature.
DISPLAY can be a display name or a frame.
If DISPLAY is omitted or nil, it defaults to the selected frame's display."
(let ((frame-type (framep-on-display display)))
(cond
((memq frame-type '(x w32 ns haiku pgtk android))
(x-display-save-under display))
(t
'not-useful))))