(declare-function x-display-screens "xfns.c" (&optional terminal))
(defun display-screens (&optional display)
- "Return the number of screens associated with DISPLAY."
+ "Return the number of screens associated with DISPLAY.
+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))
For graphical terminals, note that on \"multi-monitor\" setups this
refers to the pixel height for all physical monitors associated
with DISPLAY. To get information for each physical monitor, use
-`display-monitor-attributes-list'."
+`display-monitor-attributes-list'.
+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))
For graphical terminals, note that on \"multi-monitor\" setups this
refers to the pixel width for all physical monitors associated
with DISPLAY. To get information for each physical monitor, use
-`display-monitor-attributes-list'."
+`display-monitor-attributes-list'.
+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))
For graphical terminals, note that on \"multi-monitor\" setups this
refers to the height in millimeters for all physical monitors
associated with DISPLAY. To get information for each physical
-monitor, use `display-monitor-attributes-list'."
+monitor, use `display-monitor-attributes-list'.
+If DISPLAY is omitted or nil, it defaults to the selected frame's display."
(and (memq (framep-on-display display) '(x w32 ns))
(or (cddr (assoc (or display (frame-parameter nil 'display))
display-mm-dimensions-alist))
For graphical terminals, note that on \"multi-monitor\" setups this
refers to the width in millimeters for all physical monitors
associated with DISPLAY. To get information for each physical
-monitor, use `display-monitor-attributes-list'."
+monitor, use `display-monitor-attributes-list'.
+If DISPLAY is omitted or nil, it defaults to the selected frame's display."
(and (memq (framep-on-display display) '(x w32 ns))
(or (cadr (assoc (or display (frame-parameter nil 'display))
display-mm-dimensions-alist))
(defun display-backing-store (&optional display)
"Return the backing store capability of DISPLAY's screen.
The value may be `always', `when-mapped', `not-useful', or nil if
-the question is inapplicable to a certain kind of display."
+the question is inapplicable to a certain kind of display.
+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))
(declare-function x-display-save-under "xfns.c" (&optional terminal))
(defun display-save-under (&optional display)
- "Return non-nil if DISPLAY's screen supports the SaveUnder feature."
+ "Return non-nil if DISPLAY's screen supports the SaveUnder feature.
+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))
(declare-function x-display-planes "xfns.c" (&optional terminal))
(defun display-planes (&optional display)
- "Return the number of planes supported by DISPLAY."
+ "Return the number of planes supported by DISPLAY.
+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))
(declare-function x-display-color-cells "xfns.c" (&optional terminal))
(defun display-color-cells (&optional display)
- "Return the number of color cells supported by DISPLAY."
+ "Return the number of color cells supported by DISPLAY.
+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))
(defun display-visual-class (&optional display)
"Return the visual class of DISPLAY.
The value is one of the symbols `static-gray', `gray-scale',
-`static-color', `pseudo-color', `true-color', or `direct-color'."
+`static-color', `pseudo-color', `true-color', or `direct-color'.
+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))
physical monitors. Every non-tip frame (including invisible one)
in a graphical display is dominated by exactly one physical
monitor at a time, though it can span multiple (or no) physical
-monitors."
+monitors.
+If DISPLAY is omitted or nil, it defaults to the selected frame's display."
(let ((frame-type (framep-on-display display)))
(cond
((eq frame-type 'x)