Use display-graphic-p and display-multi-frame-p in more cases

* lisp/disp-table.el:
* lisp/faces.el:
* lisp/frame.el:
* lisp/info.el (Info-fontify-node):
* lisp/window.el (handle-select-window): Use display-graphic-p and
  display-multi-frame-p instead of explicit memq calls.

lisp/disp-table.el

@@ -175,8 +175,8 @@ in the default way after this call."
 (defun standard-display-g1 (c sc)
   "Display character C as character SC in the g1 character set.
 This function assumes that your terminal uses the SO/SI characters;
-it is meaningless for an X frame."
-  (if (memq window-system '(x w32 ns))
+it is meaningless for a graphical frame."
+  (if (display-graphic-p)
       (error "Cannot use string glyphs in a windowing system"))
   (or standard-display-table
       (setq standard-display-table (make-display-table)))
@@ -186,9 +186,9 @@ it is meaningless for an X frame."
 ;;;###autoload
 (defun standard-display-graphic (c gc)
   "Display character C as character GC in graphics character set.
-This function assumes VT100-compatible escapes; it is meaningless for an
-X frame."
-  (if (memq window-system '(x w32 ns))
+This function assumes VT100-compatible escapes; it is meaningless
+for a graphical frame."
+  (if (display-graphic-p)
       (error "Cannot use string glyphs in a windowing system"))
   (or standard-display-table
       (setq standard-display-table (make-display-table)))
@@ -276,7 +276,7 @@ in `.emacs'."
       (progn
 	(standard-display-default
 	 (unibyte-char-to-multibyte 160) (unibyte-char-to-multibyte 255))
-	(unless (or (memq window-system '(x w32 ns)))
+	(unless (display-graphic-p)
 	  (and (terminal-coding-system)
 	       (set-terminal-coding-system nil))))
 
@@ -289,7 +289,7 @@ in `.emacs'."
     ;; unless some other has been specified.
     (if (equal current-language-environment "English")
 	(set-language-environment "latin-1"))
-    (unless (or noninteractive (memq window-system '(x w32 ns)))
+    (unless (or noninteractive (display-graphic-p))
       ;; Send those codes literally to a character-based terminal.
       ;; If we are using single-byte characters,
       ;; it doesn't matter which coding system we use.

lisp/faces.el

@@ -55,6 +55,7 @@ This means to treat a terminal of type TYPE as if it were of type ALIAS."
   :group 'terminals
   :version "25.1")
 
+(declare-function display-graphic-p "frame" (&optional display))
 (declare-function xw-defined-colors "term/common-win" (&optional frame))
 
 (defvar help-xref-stack-item)
@@ -1239,7 +1240,7 @@ of a global face.  Value is the new attribute value."
 	       ;; explicitly in VALID, using color approximation code
 	       ;; in tty-colors.el.
 	       (when (and (memq attribute '(:foreground :background))
-			  (not (memq (window-system frame) '(x w32 ns)))
+			  (not (display-graphic-p frame))
 			  (not (member new-value
 				       '("unspecified"
 					 "unspecified-fg" "unspecified-bg"))))
@@ -1833,7 +1834,7 @@ The argument FRAME specifies which frame to try.
 The value may be different for frames on different display types.
 If FRAME doesn't support colors, the value is nil.
 If FRAME is nil, that stands for the selected frame."
-  (if (memq (framep (or frame (selected-frame))) '(x w32 ns))
+  (if (display-graphic-p frame)
       (xw-defined-colors frame)
     (mapcar 'car (tty-color-alist frame))))
 (defalias 'x-defined-colors 'defined-colors)
@@ -1877,7 +1878,7 @@ or one of the strings \"unspecified-fg\" or \"unspecified-bg\".
 
 If FRAME is omitted or nil, use the selected frame."
   (unless (member color '(unspecified "unspecified-bg" "unspecified-fg"))
-    (if (member (framep (or frame (selected-frame))) '(x w32 ns))
+    (if (display-graphic-p frame)
 	(xw-color-defined-p color frame)
       (numberp (tty-color-translate color frame)))))
 (defalias 'x-color-defined-p 'color-defined-p)
@@ -1903,7 +1904,7 @@ return value is nil."
   (cond
    ((member color '(unspecified "unspecified-fg" "unspecified-bg"))
     nil)
-   ((memq (framep (or frame (selected-frame))) '(x w32 ns))
+   ((display-graphic-p frame)
     (xw-color-values color frame))
    (t
     (tty-color-values color frame))))
@@ -1917,7 +1918,7 @@ return value is nil."
 The optional argument DISPLAY specifies which display to ask about.
 DISPLAY should be either a frame or a display name (a string).
 If omitted or nil, that stands for the selected frame's display."
-  (if (memq (framep-on-display display) '(x w32 ns))
+  (if (display-graphic-p display)
       (xw-display-color-p display)
     (tty-display-color-p display)))
 (defalias 'x-display-color-p 'display-color-p)
@@ -1928,12 +1929,9 @@ If omitted or nil, that stands for the selected frame's display."
   "Return non-nil if frames on DISPLAY can display shades of gray.
 DISPLAY should be either a frame or a display name (a string).
 If omitted or nil, that stands for the selected frame's display."
-  (let ((frame-type (framep-on-display display)))
-    (cond
-     ((memq frame-type '(x w32 ns))
-      (x-display-grayscale-p display))
-     (t
-      (> (tty-color-gray-shades display) 2)))))
+  (if (display-graphic-p display)
+      (x-display-grayscale-p display)
+    (> (tty-color-gray-shades display) 2)))
 
 (defun read-color (&optional prompt convert-to-RGB allow-empty-name msg)
   "Read a color name or RGB triplet.

lisp/frame.el

@@ -974,7 +974,7 @@ recently selected windows nor the buffer list."
   (select-frame frame norecord)
   (raise-frame frame)
   ;; Ensure, if possible, that FRAME gets input focus.
-  (when (memq (window-system frame) '(x w32 ns))
+  (when (display-multi-frame-p frame)
     (x-focus-frame frame))
   ;; Move mouse cursor if necessary.
   (cond
@@ -1027,16 +1027,15 @@ that variable should be nil."
   "Do whatever is right to suspend the current frame.
 Calls `suspend-emacs' if invoked from the controlling tty device,
 `suspend-tty' from a secondary tty device, and
-`iconify-or-deiconify-frame' from an X frame."
+`iconify-or-deiconify-frame' from a graphical frame."
   (interactive)
-  (let ((type (framep (selected-frame))))
   (cond
-     ((memq type '(x ns w32)) (iconify-or-deiconify-frame))
-     ((eq type t)
+   ((display-multi-frame-p) (iconify-or-deiconify-frame))
+   ((eq (framep (selected-frame)) t)
     (if (controlling-tty-p)
         (suspend-emacs)
       (suspend-tty)))
-     (t (suspend-emacs)))))
+   (t (suspend-emacs))))
 
 (defun make-frame-names-alist ()
   ;; Only consider the frames on the same display.

lisp/info.el

@@ -4768,7 +4768,7 @@ first line or header line, and for breadcrumb links.")
             ;; This is a serious problem for trying to handle multiple
             ;; frame types at once.  We want this text to be invisible
             ;; on frames that can display the font above.
-            (when (memq (framep (selected-frame)) '(x pc w32 ns))
+            (when (display-multi-font-p)
               (add-text-properties (1- (match-beginning 2)) (match-end 2)
                                    '(invisible t front-sticky nil rear-nonsticky t))))))
 

lisp/window.el

@@ -9314,6 +9314,8 @@ is active.  This function is run by `mouse-autoselect-window-timer'."
      ;; autoselection.
      (mouse-autoselect-window-start mouse-position window)))))
 
+(declare-function display-multi-frame-p "frame" (&optional display))
+
 (defun handle-select-window (event)
   "Handle select-window events."
   (interactive "^e")
@@ -9351,7 +9353,7 @@ is active.  This function is run by `mouse-autoselect-window-timer'."
       ;; we might get two windows with an active cursor.
       (select-window window)
       (cond
-       ((or (not (memq (window-system frame) '(x w32 ns)))
+       ((or (not (display-multi-frame-p))
             (not focus-follows-mouse)
             ;; Focus FRAME if it's either a child frame or an ancestor
             ;; of the frame switched from.