Re: list-colors-display: display all color names

[Juri Linkov]

Michael Mauger <address@hidden> writes:
> Does matching on the name rather than the color value result in a different 
> output with your other changes?  Should we match on color value unless the 
> name 
> starts with the string "System"?

The problem is that "SystemMenuText" and "SystemText" are not color names,
but rather color settings.  Matching them by name is not a reliable solution.
There is a likelihood of non-Windows color names starting with the string
"System", or Windows colors having name without the string "System".

I looked a little at Windows-related Emacs files, and see that the
variable `w32-default-color-map' does not contain Window theme colors.
I think it could be used to match Window theme color by a condition like

    (not (and (boundp 'w32-default-color-map)
         (not (assoc (car (car l)) w32-default-color-map))))

I don't use Windows, so I can't check it.  Could you see if all names are
displayed correctly?  Then do you have any objections to the following patch?

Index: lisp/facemenu.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/facemenu.el,v
retrieving revision 1.73
diff -u -r1.73 facemenu.el
--- lisp/facemenu.el    4 Sep 2004 19:11:18 -0000       1.73
+++ lisp/facemenu.el    29 Dec 2004 19:02:09 -0000
@@ -471,50 +471,66 @@
       col)))
 
 ;;;###autoload
-(defun list-colors-display (&optional list)
+(defun list-colors-display (&optional list buffer-name)
   "Display names of defined colors, and show what they look like.
 If the optional argument LIST is non-nil, it should be a list of
-colors to display.  Otherwise, this command computes a list
-of colors that the current display can handle."
+colors to display.  Otherwise, this command computes a list of
+colors that the current display can handle.  If the optional
+argument BUFFER-NAME is nil, it defaults to *Colors*."
   (interactive)
   (when (and (null list) (> (display-color-cells) 0))
-    (setq list (defined-colors))
-    ;; Delete duplicate colors.
-
-    ;; Identify duplicate colors by the name rather than the color
-    ;; value.  For example, on MS-Windows, logical colors are added to
-    ;; the list that might have the same value but have different
-    ;; names and meanings.  For example, `SystemMenuText' (the color
-    ;; w32 uses for the text in menu entries) and `SystemWindowText'
-    ;; (the default color w32 uses for the text in windows and
-    ;; dialogs) may be the same display color and be adjacent in the
-    ;; list.  Detecting duplicates by name insures that both of these
-    ;; colors remain despite identical color values.
-    (let ((l list))
-      (while (cdr l)
-       (if (facemenu-color-name-equal (car l) (car (cdr l)))
-           (setcdr l (cdr (cdr l)))
-         (setq l (cdr l)))))
+    (setq list (list-colors-duplicates (defined-colors)))
     (when (memq (display-visual-class) '(gray-scale pseudo-color direct-color))
       ;; Don't show more than what the display can handle.
       (let ((lc (nthcdr (1- (display-color-cells)) list)))
        (if lc
            (setcdr lc nil)))))
-  (with-output-to-temp-buffer "*Colors*"
+  (with-output-to-temp-buffer (or buffer-name "*Colors*")
     (save-excursion
       (set-buffer standard-output)
-      (let (s)
-       (while list
-         (setq s (point))
-         (insert (car list))
-         (indent-to 20)
-         (put-text-property s (point) 'face
-                            (cons 'background-color (car list)))
-         (setq s (point))
-         (insert "  " (car list) "\n")
-         (put-text-property s (point) 'face
-                            (cons 'foreground-color (car list)))
-         (setq list (cdr list)))))))
+      (setq truncate-lines t)
+      (dolist (color list)
+       (if (consp color)
+           (if (cdr color)
+               (setq color (sort color (lambda (a b)
+                                         (string< (downcase a)
+                                                  (downcase b))))))
+         (setq color (list color)))
+       (put-text-property
+        (prog1 (point)
+          (insert (car color))
+          (indent-to 22))
+        (point)
+        'face (cons 'background-color (car color)))
+       (put-text-property
+        (prog1 (point)
+          (insert "  " (if (cdr color)
+                           (mapconcat 'identity (cdr color) ", ")
+                         (car color))
+                  "\n"))
+        (point)
+        'face (cons 'foreground-color (car color)))))))
+
+(defun list-colors-duplicates (&optional list)
+  "Return a list of colors with grouped duplicate colors.
+If a color has no duplicates, then the element of the returned list
+has the form '(COLOR-NAME).  The element of the returned list with
+duplicate colors has the form '(COLOR-NAME DUPLICATE-COLOR-NAME ...).
+This function uses the predicate `facemenu-color-equal' to compare
+color names.  If the optional argument LIST is non-nil, it should
+be a list of colors to display.  Otherwise, this function uses
+a list of colors that the current display can handle."
+  (let* ((list (mapcar 'list (or list (defined-colors))))
+        (l list))
+    (while (cdr l)
+      (if (and (facemenu-color-equal (car (car l)) (car (car (cdr l))))
+              (not (and (boundp 'w32-default-color-map)
+                        (not (assoc (car (car l)) w32-default-color-map)))))
+         (progn
+           (setcdr (car l) (cons (car (car (cdr l))) (cdr (car l))))
+           (setcdr l (cdr (cdr l))))
+       (setq l (cdr l))))
+    list))
 
 (defun facemenu-color-equal (a b)
   "Return t if colors A and B are the same color.
@@ -525,22 +541,6 @@
   (cond ((equal a b) t)
        ((equal (color-values a) (color-values b)))))
 
-(defun facemenu-color-name-equal (a b)
-  "Return t if colors A and B are the same color.
-A and B should be strings naming colors.  These names are
-downcased, stripped of spaces and the string `grey' is turned
-into `gray'.  This accommodates alternative spellings of colors
-found commonly in the list.  It returns nil if the colors differ."
-  (progn
-    (setq a (replace-regexp-in-string "grey" "gray"
-            (replace-regexp-in-string " " ""
-             (downcase a)))
-         b (replace-regexp-in-string "grey" "gray"
-            (replace-regexp-in-string " " ""
-             (downcase b))))
-
-    (equal a b)))
-
 (defun facemenu-add-face (face &optional start end)
   "Add FACE to text between START and END.
 If START is nil or START to END is empty, add FACE to next typed character

-- 
Juri Linkov
http://www.jurta.org/emacs/