Detect window-system from display name

1 files changed, 32 insertions, 21 deletions

diff --git a/lisp/frame.el b/lisp/frame.el
index 9be64a6b7ff..1e8883eb98e 100644
--- a/lisp/frame.el
+++ b/lisp/frame.el
@@ -25,6 +25,8 @@
 ;;; Commentary:
 
 ;;; Code:
+(eval-when-compile (require 'cl-lib))
+
 (defvar frame-creation-function-alist
   (list (cons nil
 	      (if (fboundp 'tty-create-frame-with-faces)
@@ -45,6 +47,12 @@ Then, for frames on WINDOW-SYSTEM, any parameters specified in
 ALIST supersede the corresponding parameters specified in
 `default-frame-alist'.")
 
+(defvar display-format-alist nil
+  "Alist of patterns to decode display names.
+The car of each entry is a regular expression matching a display
+name string.  The cdr is a symbol giving the window-system that
+handles the corresponding kind of display.")
+
 ;; The initial value given here used to ask for a minibuffer.
 ;; But that's not necessary, because the default is to have one.
 ;; By not specifying it here, we let an X resource specify it.
@@ -510,31 +518,19 @@ is not considered (see `next-frame')."
 				  0))
   (select-frame-set-input-focus (selected-frame)))
 
-(declare-function x-initialize-window-system "term/x-win" ())
-(declare-function ns-initialize-window-system "term/ns-win" ())
-(defvar x-display-name)                 ; term/x-win
+(defun window-system-for-display (display)
+  "Return the window system for DISPLAY.
+Return nil if we don't know how to interpret DISPLAY."
+  (cl-loop for descriptor in display-format-alist
+           for pattern = (car descriptor)
+           for system = (cdr descriptor)
+           when (string-match-p pattern display) return system))
 
 (defun make-frame-on-display (display &optional parameters)
   "Make a frame on display DISPLAY.
 The optional argument PARAMETERS specifies additional frame parameters."
   (interactive "sMake frame on display: ")
-  (cond ((featurep 'ns)
-	 (when (and (boundp 'ns-initialized) (not ns-initialized))
-	   (setq x-display-name display)
-	   (ns-initialize-window-system))
-	 (make-frame `((window-system . ns)
-		       (display . ,display) . ,parameters)))
-	((eq window-system 'w32)
-	 ;; On Windows, ignore DISPLAY.
-	 (make-frame parameters))
-	(t
-	 (unless (string-match-p "\\`[^:]*:[0-9]+\\(\\.[0-9]+\\)?\\'" display)
-	   (error "Invalid display, not HOST:SERVER or HOST:SERVER.SCREEN"))
-	 (when (and (boundp 'x-initialized) (not x-initialized))
-	   (setq x-display-name display)
-	   (x-initialize-window-system))
-	 (make-frame `((window-system . x)
-		       (display . ,display) . ,parameters)))))
+  (make-frame (cons (cons 'display display) parameters)))
 
 (declare-function x-close-connection "xfns.c" (terminal))
 
@@ -616,6 +612,8 @@ neither or both.
  (window-system . nil)	The frame should be displayed on a terminal device.
  (window-system . x)	The frame should be displayed in an X window.
 
+ (display . \":0\")     The frame should appear on display :0.
+
  (terminal . TERMINAL)  The frame should use the terminal object TERMINAL.
 
 In addition, any parameter specified in `default-frame-alist',
@@ -626,11 +624,15 @@ this function runs the hook `before-make-frame-hook'.  After
 creating the frame, it runs the hook `after-make-frame-functions'
 with one arg, the newly created frame.
 
+If a display parameter is supplied and a window-system is not,
+guess the window-system from the display.
+
 On graphical displays, this function does not itself make the new
 frame the selected frame.  However, the window system may select
 the new frame according to its own rules."
   (interactive)
-  (let* ((w (cond
+  (let* ((display (cdr (assq 'display parameters)))
+         (w (cond
 	     ((assq 'terminal parameters)
 	      (let ((type (terminal-live-p (cdr (assq 'terminal parameters)))))
 		(cond
@@ -640,6 +642,10 @@ the new frame according to its own rules."
 		 (t type))))
 	     ((assq 'window-system parameters)
 	      (cdr (assq 'window-system parameters)))
+             (display
+              (or (window-system-for-display display)
+                  (error "Don't know how to interpret display \"%S\""
+                         display)))
 	     (t window-system)))
 	 (frame-creation-function (cdr (assq w frame-creation-function-alist)))
 	 (oldframe (selected-frame))
@@ -647,6 +653,11 @@ the new frame according to its own rules."
 	 frame)
     (unless frame-creation-function
       (error "Don't know how to create a frame on window system %s" w))
+
+    (unless (get w 'window-system-initialized)
+      (funcall (cdr (assq w window-system-initialization-alist)))
+      (put w 'window-system-initialized t))
+
     ;; Add parameters from `window-system-default-frame-alist'.
     (dolist (p (cdr (assq w window-system-default-frame-alist)))
       (unless (assq (car p) params)