Re: emacs-21 and gnus

[Colin Walters <walters@cis.ohio-state.edu>]

Colin Marquardt <colin.marquardt@usa.alcatel.com> writes:

> Some users still might want that, true. If not, it adds some
> incentive to switch to Emacs 21 ;-)

It does look nice in Emacs 21.  Screen shot at:

<URL:http://www.cis.ohio-state.edu/~walters/shot.jpg>

> What do they get on the console?

An arrow overlay, just like in Emacs20 and XEmacs.

> Sounds reasonable to me. Or maybe set it to nil per default, and
> after people start using and liking it, make t the default.

Another option is to make it turned on by default only if:

(and (string-match "GNU" (emacs-version))
     (>= emacs-major-version 21)
     (display-graphic-p))

> Unfortunately, I cannot really try your first patch since I still
> didn't switch the either XEmacs 21.4 or Emacs 21 (which is more
> likely to happen).

Well, it does work in Emacs 20, too.  It *should* work in XEmacs, but
I haven't tried it, because my init files and everything are too
tightly bound to GNU Emacs.

Here's an updated patch (supersedes the old one):

2001-07-12  Colin Walters  <walters@cis.ohio-state.edu>

	* gnus-sum.el (gnus-summary-display-arrow): New variable.
	(gnus-summary-set-article-display-arrow): New function.
	(gnus-summary-goto-subject): Use it.

--- gnus-sum.el.~6.72.~	Thu Jul 12 13:04:12 2001
+++ gnus-sum.el	Fri Jul 13 00:44:36 2001
@@ -797,6 +797,15 @@
   :group 'gnus-summary
   :type 'hook)
 
+(defcustom gnus-summary-display-arrow
+  (and (string-match "GNU" (emacs-version))
+       (>= emacs-major-version 21)
+       (display-graphic-p))
+  "*If non-nil, display an arrow highlighting the current article."
+  :version "21.1"
+  :group 'gnus-summary
+  :type 'boolean)
+
 (defcustom gnus-summary-selected-face 'gnus-summary-selected-face
   "Face used for highlighting the current article in the summary buffer."
   :group 'gnus-summary-visual
@@ -2703,6 +2712,21 @@
 	  (aset table i [??]))))
     (setq buffer-display-table table)))
 
+(defun gnus-summary-set-article-display-arrow (pos)
+  "Update the overlay arrow to point to line at position POS."
+  (when (and gnus-summary-display-arrow
+	     (boundp 'overlay-arrow-position)
+	     (boundp 'overlay-arrow-string))
+    (save-excursion
+      (goto-char pos)
+      (beginning-of-line)
+      (unless overlay-arrow-position
+	(setq overlay-arrow-position (make-marker)))
+      (setq overlay-arrow-string "=>"
+	    overlay-arrow-position (set-marker overlay-arrow-position
+					       (point)
+					       (current-buffer))))))
+
 (defun gnus-summary-buffer-name (group)
   "Return the summary buffer name of GROUP."
   (concat "*Summary " group "*"))
@@ -6123,7 +6147,9 @@
 	  (unless silent
 	    (gnus-message 3 "Can't find article %d" article))
 	  nil)
-      (goto-char (gnus-data-pos data))
+      (let ((pt (gnus-data-pos data)))
+	(goto-char pt)
+	(gnus-summary-set-article-display-arrow pt))
       (gnus-summary-position-point)
       article)))