[Erc-help] Proposed patch: make erc-button-face override existing faces

[Francis L. <fr...@wo...>]

ERCers,

This proposed patch makes erc-button-face have priority over existing
faces when erc-button.el buttonizes an URL.  To see why this is an
issue, eval this code, and then type /TOPIC in a channel that has URLs
in its topic:

	(progn
	  (require 'erc-button)
	  (erc-button-mode 1)
	  (set-face-foreground (make-face 'my-button-face) "yellow")
	  (setq erc-button-face 'my-button-face)
	  (set-face-foreground 'erc-notice-face "red"))

The face of the URLs in the topic ends up being the list

	(erc-notice-face my-button-face)

but with this patch, it would be

	(my-button-face erc-notice-face)

giving priority to the button face.  The reasoning here is that the
button-ness of a button is more important than the notice-ness of a
notice (or whatever the ambient text face may be).

If I don't hear objections, in a few days I'm commit this patch.  This
patch also fixes a byte-compiler warning about too-few arguments in a
call to `error'.
--
Francis Litterio
franl <at> world . std . com


--- erc-button.el	16 Jan 2005 09:17:51 -0500	1.60
+++ erc-button.el	17 Jan 2005 07:11:50 -0500	
@@ -1,4 +1,4 @@
-;;; erc-button.el --- A way of buttonizing certain things in ERC buffers
+;; erc-button.el --- A way of buttonizing certain things in ERC buffers
 
 ;; Copyright (C) 1996,1997,1998,1999,2000,2001,2002,2003,2004
 ;;        Free Software Foundation, Inc.
@@ -80,6 +80,14 @@
   :type 'face
   :group 'erc-faces)
 
+(defcustom erc-button-face-has-priority t
+  "Flag indicating whether erc-button-face overrides existing faces.
+
+If non-nil, buttons displayed with erc-button-face will have that face
+merged into any existing faces on the button text with higher priority."
+  :type 'boolean
+  :group 'erc-faces)
+
 (defcustom erc-button-url-regexp "\\(www\\.\\|\\(s?https?\\|ftp\\|file\\|gopher\\|news\\|telnet\\|wais\\|mailto\\):\\)\\(//[-a-zA-Z0-9_.]+:[0-9]*\\)?[-a-zA-Z0-9_=!?#$@~`%&*+\\/:;.,]+[-a-zA-Z0-9_=#$@~`%&*+\\/]"
   "Regular expression that matches URLs."
   :group 'erc-button
@@ -360,7 +368,11 @@
     ;; new face is a list containing FACE and the old stuff.  end is
     ;; where this face changes.
     (while (< pos to)
-      (setq new (if old (append old (erc-list face)) face))
+      (setq new (if old
+		    (if erc-button-face-has-priority
+			(append (erc-list face) old)
+		      (append old (erc-list face)))
+		  face))
       (put-text-property pos end 'face new)
       (setq pos end
             old (erc-list (get-text-property pos 'face))
@@ -389,7 +401,7 @@
     (unless fun
       (message "No button at point"))
     (when (and fun (symbolp fun) (not (fboundp fun)))
-      (error "Function %S is not bound"))
+      (error "Function %S is not bound" fun))
     (apply fun data)))
 
 (defun erc-button-next ()