Initial revision

1 files changed, 179 insertions, 0 deletions

diff --git a/lisp/gnus/gnus-mule.el b/lisp/gnus/gnus-mule.el
new file mode 100644
index 00000000000..b7abab722d3
--- /dev/null
+++ b/lisp/gnus/gnus-mule.el
@@ -0,0 +1,179 @@
+;; gnus-mule.el -- Provide multilingual environment to GNUS
+
+;; Copyright (C) 1995 Free Software Foundation, Inc.
+;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
+
+;; Keywords: gnus, mule
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Commentary:
+
+;; This package enables GNUS to code convert automatically
+;; accoding to a coding system specified for each news group.
+;; Please put the following line in your .emacs:
+;;	(add-hook 'gnus-startup-hook 'gnus-mule-initialize)
+;; If you want to specify some coding system for a specific news
+;; group, add the fllowing line in your .emacs:
+;;	(gnus-mule-add-group "xxx.yyy.zzz" 'some-coding-system)
+;;
+;; Decoding of summary buffer is not yet implemented.
+
+(require 'gnus)
+
+(defvar gnus-newsgroup-coding-systems nil
+  "Assoc list of news groups vs corresponding coding systems.
+Each element is a list of news group name and cons of coding systems
+for reading and posting.")
+
+;;;###autoload
+(defun gnus-mule-add-group (name coding-system)
+  "Specify that articles of news group NAME are encoded in CODING-SYSTEM.
+All news groups deeper than NAME are also the target.
+If CODING-SYSTEM is a cons, the car and cdr part are regarded as
+coding-system for reading and writing respectively."
+  (if (not (consp coding-system))
+      (setq coding-system (cons coding-system coding-system)))
+  (setq name (concat "^" (regexp-quote name)))
+  (let ((group (assoc name gnus-newsgroup-coding-systems)))
+    (if group
+	(setcdr group coding-system)
+      (setq gnus-newsgroup-coding-systems
+	    (cons (cons name coding-system) gnus-newsgroup-coding-systems)))))
+
+(defun gnus-mule-get-coding-system (group)
+  "Return the coding system for news group GROUP."
+  (let ((groups gnus-newsgroup-coding-systems)
+	(len -1)
+	coding-system)
+    ;; Find an entry which matches GROUP the best (i.e. longest).
+    (while groups
+      (if (and (string-match (car (car groups)) group)
+	       (> (match-end 0) len))
+	  (setq len (match-end 0)
+		coding-system (cdr (car groups))))
+      (setq groups (cdr groups)))
+    coding-system))
+
+;; Flag to indicate if article buffer is already decoded or not.")
+(defvar gnus-mule-article-decoded nil)
+;; Codingsystem for reading articles of the current news group.
+(defvar gnus-mule-coding-system nil)
+(defvar gnus-mule-subject nil)
+(defvar gnus-mule-decoded-subject nil)
+(defvar gnus-mule-original-subject nil)
+
+;; Encode (if ENCODING is t) or decode (if ENCODING is nil)  the
+;; region from START to END by CODING-SYSTEM.
+(defun gnus-mule-code-convert1 (start end coding-system encoding)
+  (if (< start end)
+      (save-excursion
+       (if encoding
+	   (encode-coding-region start end coding-system)
+	 (decode-coding-region start end coding-system)))))
+
+;; Encode (if ENCODING is t) or decode (if ENCODING is nil) the
+;; current buffer by CODING-SYSTEM.  Try not to move positions of
+;; (window-start) and (point).
+(defun gnus-mule-code-convert (coding-system encoding)
+  (if coding-system
+      (let ((win (get-buffer-window (current-buffer))))
+	(if win
+	    ;; We should keep (point) and (window-start).
+	    (save-window-excursion
+	      (select-window win)
+	      (if encoding
+		  ;; Simple way to assure point is on valid character boundary.
+		  (beginning-of-line))
+	      (gnus-mule-code-convert1 (point-min) (window-start)
+				       coding-system encoding)
+	      (gnus-mule-code-convert1 (window-start) (point)
+				       coding-system encoding)
+	      (gnus-mule-code-convert1 (point) (point-max)
+				       coding-system encoding)
+	      (if (not (pos-visible-in-window-p))
+		  ;; point went out of window, move to the bottom of window.
+		  (move-to-window-line -1)))
+	  ;; No window for the buffer, no need to worry about (point)
+	  ;; and (windos-start).
+	  (gnus-mule-code-convert1 (point-min) (point-max)
+				   coding-system encoding))
+	)))
+
+;; Set `gnus-mule-coding-system' to the coding system articles of the
+;; current news group is encoded.   This function is set in
+;; `gnus-select-group-hook'.
+(defun gnus-mule-select-coding-system ()
+  (let ((coding-system (gnus-mule-get-coding-system gnus-newsgroup-name)))
+    (setq gnus-mule-coding-system
+	  (if (and coding-system (coding-system-p (car coding-system)))
+	      (car coding-system)))))
+
+;; Decode the current article.  This function is set in
+;; `gnus-article-prepare-hook'.
+(defun gnus-mule-decode-article ()
+  (gnus-mule-code-convert gnus-mule-coding-system nil)
+  (setq gnus-mule-article-decoded t))
+
+;; Decode the current summary buffer.  This function is set in
+;; `gnus-summary-prepare-hook'. 
+(defun gnus-mule-decode-summary ()
+  ;; I have not yet implemented this function because I'm not yet
+  ;; familiar with the new Gnus codes, especialy how to extract only
+  ;; subjects from a summary buffer.
+  nil)
+
+(defun gnus-mule-toggle-article-format ()
+  "Toggle decoding/encoding of the current article buffer."
+  (interactive)
+  (let ((buf (get-buffer gnus-article-buffer)))
+    (if (and gnus-mule-coding-system buf)
+	(save-excursion
+	  (set-buffer buf)
+	  (let ((modif (buffer-modified-p))
+		buffer-read-only)
+	    (gnus-mule-code-convert gnus-mule-coding-system
+				   gnus-mule-article-decoded)
+	    (setq gnus-mule-article-decoded (not gnus-mule-article-decoded))
+	    (set-buffer-modified-p modif))))))
+
+;;;###autoload
+(defun gnus-mule-initialize ()
+  "Do several settings for GNUS to enable automatic code conversion."
+  ;; Convenient key definitions
+  (define-key gnus-article-mode-map "z" 'gnus-mule-toggle-article-format)
+  (define-key gnus-summary-mode-map "z" 'gnus-mule-toggle-article-format)
+  ;; Hook definition
+  (add-hook 'gnus-select-group-hook 'gnus-mule-select-coding-system)
+  (add-hook 'gnus-summary-prepare-hook 'gnus-mule-decode-summary)
+  (add-hook 'gnus-article-prepare-hook 'gnus-mule-decode-article))
+
+(gnus-mule-add-group "" 'coding-system-iso-2022-7) ;; default coding system
+(gnus-mule-add-group "alt" 'no-conversion)
+(gnus-mule-add-group "comp" 'no-conversion)
+(gnus-mule-add-group "gnu" 'no-conversion)
+(gnus-mule-add-group "rec" 'no-conversion)
+(gnus-mule-add-group "sci" 'no-conversion)
+(gnus-mule-add-group "soc" 'no-conversion)
+(gnus-mule-add-group "alt.chinese.text" 'coding-system-hz)
+(gnus-mule-add-group "alt.hk" 'coding-system-hz)
+(gnus-mule-add-group "alt.chinese.text.big5" 'coding-system-big5)
+(gnus-mule-add-group "soc.culture.vietnamese" '(nil . coding-system-viqr))
+
+(add-hook 'gnus-startup-hook 'gnus-mule-initialize)
+
+;; gnus-mule.el ends here