source: projects/emacsen-common/branches/0.4.x/apel-sample/usr/share/emacs/site-lisp/apel/mcs-e20.el @ 7238

;;; mcs-e20.el --- MIME charset implementation for Emacs 20.1 and 20.2

;; Copyright (C) 1996,1997,1998,1999,2000 Free Software Foundation, Inc.

;; Author: MORIOKA Tomohiko <tomo@m17n.org>
;; Keywords: emulation, compatibility, Mule

;; This file is part of APEL (A Portable Emacs Library).

;; This program 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.

;; This program 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, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;    This module requires Emacs 20.1 and 20.2.

;;; Code:

(require 'pces)
(eval-when-compile (require 'static))

(defsubst encode-mime-charset-region (start end charset &optional lbt)
  "Encode the text between START and END as MIME CHARSET."
  (let (cs)
    (if (and enable-multibyte-characters
             (setq cs (mime-charset-to-coding-system charset lbt)))
        (encode-coding-region start end cs)
      )))

(defsubst decode-mime-charset-region (start end charset &optional lbt)
  "Decode the text between START and END as MIME CHARSET."
  (let (cs)
    (if (and enable-multibyte-characters
             (setq cs (mime-charset-to-coding-system charset lbt)))
        (decode-coding-region start end cs)
      )))


(defsubst encode-mime-charset-string (string charset &optional lbt)
  "Encode the STRING as MIME CHARSET."
  (let (cs)
    (if (and enable-multibyte-characters
             (setq cs (mime-charset-to-coding-system charset lbt)))
        (encode-coding-string string cs)
      string)))

(defsubst decode-mime-charset-string (string charset &optional lbt)
  "Decode the STRING as MIME CHARSET."
  (let (cs)
    (if (and enable-multibyte-characters
             (setq cs (mime-charset-to-coding-system charset lbt)))
        (decode-coding-string string cs)
      string)))


(defvar charsets-mime-charset-alist
  '(((ascii)                                            . us-ascii)
    ((ascii latin-iso8859-1)                            . iso-8859-1)
    ((ascii latin-iso8859-2)                            . iso-8859-2)
    ((ascii latin-iso8859-3)                            . iso-8859-3)
    ((ascii latin-iso8859-4)                            . iso-8859-4)
;;; ((ascii cyrillic-iso8859-5)                         . iso-8859-5)
    ((ascii cyrillic-iso8859-5)                         . koi8-r)
    ((ascii arabic-iso8859-6)                           . iso-8859-6)
    ((ascii greek-iso8859-7)                            . iso-8859-7)
    ((ascii hebrew-iso8859-8)                           . iso-8859-8)
    ((ascii latin-iso8859-9)                            . iso-8859-9)
    ((ascii latin-jisx0201
            japanese-jisx0208-1978 japanese-jisx0208)   . iso-2022-jp)
    ((ascii latin-jisx0201
            katakana-jisx0201 japanese-jisx0208)        . shift_jis)
    ((ascii korean-ksc5601)                             . euc-kr)
    ((ascii chinese-gb2312)                             . gb2312)
    ((ascii chinese-big5-1 chinese-big5-2)              . big5)
    ((ascii thai-tis620 composition)                    . tis-620)
    ((ascii latin-iso8859-1 greek-iso8859-7
            latin-jisx0201 japanese-jisx0208-1978
            chinese-gb2312 japanese-jisx0208
            korean-ksc5601 japanese-jisx0212)           . iso-2022-jp-2)
;     ((ascii latin-iso8859-1 greek-iso8859-7
;           latin-jisx0201 japanese-jisx0208-1978
;           chinese-gb2312 japanese-jisx0208
;           korean-ksc5601 japanese-jisx0212
;           chinese-cns11643-1 chinese-cns11643-2)      . iso-2022-int-1)
;     ((ascii latin-iso8859-1 latin-iso8859-2
;           cyrillic-iso8859-5 greek-iso8859-7
;           latin-jisx0201 japanese-jisx0208-1978
;           chinese-gb2312 japanese-jisx0208
;           korean-ksc5601 japanese-jisx0212
;           chinese-cns11643-1 chinese-cns11643-2
;           chinese-cns11643-3 chinese-cns11643-4
;           chinese-cns11643-5 chinese-cns11643-6
;           chinese-cns11643-7)                         . iso-2022-int-1)
    ))

(defun-maybe coding-system-get (coding-system prop)
  "Extract a value from CODING-SYSTEM's property list for property PROP."
  (plist-get (coding-system-plist coding-system) prop)
  )

(defun coding-system-to-mime-charset (coding-system)
  "Convert CODING-SYSTEM to a MIME-charset.
Return nil if corresponding MIME-charset is not found."
  (or (car (rassq coding-system mime-charset-coding-system-alist))
      (coding-system-get coding-system 'mime-charset)
      ))

(defun-maybe-cond mime-charset-list ()
  "Return a list of all existing MIME-charset."
  ((boundp 'coding-system-list)
   (let ((dest (mapcar (function car) mime-charset-coding-system-alist))
         (rest coding-system-list)
         cs)
     (while rest
       (setq cs (car rest))
       (unless (rassq cs mime-charset-coding-system-alist)
         (if (setq cs (coding-system-get cs 'mime-charset))
             (or (rassq cs mime-charset-coding-system-alist)
                 (memq cs dest)  
                 (setq dest (cons cs dest))
                 )))
       (setq rest (cdr rest)))
     dest))
   (t
    (let ((dest (mapcar (function car) mime-charset-coding-system-alist))
          (rest (coding-system-list))
          cs)
      (while rest
        (setq cs (car rest))
        (unless (rassq cs mime-charset-coding-system-alist)
          (when (setq cs (or (coding-system-get cs 'mime-charset)
                             (and
                              (setq cs (aref
                                        (coding-system-get cs 'coding-spec)
                                        2))
                              (string-match "(MIME:[ \t]*\\([^,)]+\\)" cs)
                              (match-string 1 cs))))
            (setq cs (intern (downcase cs)))
            (or (rassq cs mime-charset-coding-system-alist)
                (memq cs dest)
                (setq dest (cons cs dest))
                )))
        (setq rest (cdr rest)))
      dest)
    ))

(static-when (and (string= (decode-coding-string "\e.A\eN!" 'ctext) "\eN!")
                  (or (not (find-coding-system 'x-ctext))
                      (coding-system-get 'x-ctext 'apel)))
  (unless (find-coding-system 'x-ctext)
    (make-coding-system
     'x-ctext 2 ?x
     "Compound text based generic encoding for decoding unknown messages."
     '((ascii t) (latin-iso8859-1 t) t t
       nil ascii-eol ascii-cntl nil locking-shift single-shift nil nil nil
       init-bol nil nil)
     '((safe-charsets . t)
       (mime-charset . x-ctext)))
    (coding-system-put 'x-ctext 'apel t)
    ))


;;; @ end
;;;

(require 'product)
(product-provide (provide 'mcs-e20) (require 'apel-ver))

;;; mcs-e20.el ends here