Re: list-colors-display: filter same adjecent colors

[Michael Mauger]

I think we had agreed on this one.  Can it be committed?

Index: emacs/lisp/facemenu.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/facemenu.el,v
retrieving revision 1.71
diff -u -r1.71 facemenu.el
--- emacs/lisp/facemenu.el      1 Sep 2003 15:45:11 -0000       1.71
+++ emacs/lisp/facemenu.el      13 Mar 2004 21:59:20 -0000
@@ -480,9 +480,19 @@
   (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.  On w32, 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 similar color values.
     (let ((l list))
       (while (cdr l)
-       (if (facemenu-color-equal (car l) (car (cdr l)))
+       (if (facemenu-color-name-equal (car l) (car (cdr l)))
            (setcdr l (cdr (cdr l)))
          (setq l (cdr l)))))
     (when (memq (display-visual-class) '(gray-scale pseudo-color
direct-color))
@@ -514,6 +524,22 @@
 determine the correct answer."
   (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.