source: projects/emacsen-common/trunk/apel-sample/usr/share/emacs/site-lisp/apel/mcs-om.el @ 7238

;;; mcs-om.el --- MIME charset implementation for Mule 1.* and Mule 2.*

;; Copyright (C) 1995,1996,1997,1998 MORIOKA Tomohiko

;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
;; 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.

;;; Code:

(require 'poem)

(defsubst lbt-to-string (lbt)
  (cdr (assq lbt '((nil . nil)
                   (CRLF . "\r\n")
                   (CR . "\r")
                   (dos . "\r\n")
                   (mac . "\r"))))
  )

(defun encode-mime-charset-region (start end charset &optional lbt)
  "Encode the text between START and END as MIME CHARSET."
  (let ((cs (mime-charset-to-coding-system charset lbt)))
    (if cs
        (code-convert start end *internal* cs)
      (if (and lbt (setq cs (mime-charset-to-coding-system charset)))
          (let ((newline (lbt-to-string lbt)))
            (save-excursion
              (save-restriction
                (narrow-to-region start end)
                (code-convert (point-min) (point-max) *internal* cs)
                (if newline
                    (goto-char (point-min))
                  (while (search-forward "\n" nil t)
                    (replace-match newline))))))))))

(defun decode-mime-charset-region (start end charset &optional lbt)
  "Decode the text between START and END as MIME CHARSET."
  (let ((cs (mime-charset-to-coding-system charset lbt)))
    (if cs
        (code-convert start end cs *internal*)
      (if (and lbt (setq cs (mime-charset-to-coding-system charset)))
          (let ((newline (lbt-to-string lbt)))
            (if newline
                (save-excursion
                  (save-restriction
                    (narrow-to-region start end)
                    (goto-char (point-min))
                    (while (search-forward newline nil t)
                      (replace-match "\n")))
                  (code-convert (point-min) (point-max) cs *internal*))
              (code-convert start end cs *internal*)))))))

(defun encode-mime-charset-string (string charset &optional lbt)
  "Encode the STRING as MIME CHARSET."
  (let ((cs (mime-charset-to-coding-system charset lbt)))
    (if cs
        (code-convert-string string *internal* cs)
      (if (and lbt (setq cs (mime-charset-to-coding-system charset)))
          (let ((newline (lbt-to-string lbt)))
            (if newline
                (with-temp-buffer
                  (insert string)
                  (code-convert (point-min) (point-max) *internal* cs)
                  (goto-char (point-min))
                  (while (search-forward "\n" nil t)
                    (replace-match newline))
                  (buffer-string))
              (decode-coding-string string cs)))
        string))))

(defun decode-mime-charset-string (string charset &optional lbt)
  "Decode the STRING which is encoded in MIME CHARSET."
  (let ((cs (mime-charset-to-coding-system charset lbt)))
    (if cs
        (decode-coding-string string cs)
      (if (and lbt (setq cs (mime-charset-to-coding-system charset)))
          (let ((newline (lbt-to-string lbt)))
            (if newline
                (with-temp-buffer
                  (insert string)
                  (goto-char (point-min))
                  (while (search-forward newline nil t)
                    (replace-match "\n"))
                  (code-convert (point-min) (point-max) cs *internal*)
                  (buffer-string))
              (decode-coding-string string cs)))
        string))))

(cond
 ((and (>= emacs-major-version 19) (>= emacs-minor-version 29))
  ;; for MULE 2.3 based on Emacs 19.34.
  (defun write-region-as-mime-charset (charset start end filename
                                               &optional append visit lockname)
    "Like `write-region', q.v., but code-convert by MIME CHARSET."
    (let ((file-coding-system
           (or (mime-charset-to-coding-system charset)
               *noconv*)))
      (write-region start end filename append visit lockname)))
  )
 (t
  ;; for MULE 2.3 based on Emacs 19.28.
  (defun write-region-as-mime-charset (charset start end filename
                                               &optional append visit lockname)
    "Like `write-region', q.v., but code-convert by MIME CHARSET."
    (let ((file-coding-system
           (or (mime-charset-to-coding-system charset)
               *noconv*)))
      (write-region start end filename append visit)))
  ))


;;; @ to coding-system
;;;

(condition-case nil
    (require 'cyrillic)
  (error nil))

(defvar mime-charset-coding-system-alist
  '((iso-8859-1      . *ctext*)
    (x-ctext         . *ctext*)
    (gb2312          . *euc-china*)
    (koi8-r          . *koi8*)
    (iso-2022-jp-2   . *iso-2022-ss2-7*)
    (x-iso-2022-jp-2 . *iso-2022-ss2-7*)
    (shift_jis       . *sjis*)
    (x-shiftjis      . *sjis*)
    ))

(defsubst mime-charset-to-coding-system (charset &optional lbt)
  "Return coding-system corresponding with CHARSET.
CHARSET is a symbol whose name is MIME charset.
If optional argument LBT (`CRLF', `LF', `CR', `unix', `dos' or `mac')
is specified, it is used as line break code type of coding-system."
  (if (stringp charset)
      (setq charset (intern (downcase charset)))
    )
  (setq charset (or (cdr (assq charset mime-charset-coding-system-alist))
                    (intern (concat "*" (symbol-name charset) "*"))))
  (if lbt
      (setq charset (intern (format "%s%s" charset
                                    (cond ((eq lbt 'CRLF) 'dos)
                                          ((eq lbt 'LF) 'unix)
                                          ((eq lbt 'CR) 'mac)
                                          (t lbt)))))
    )
  (if (coding-system-p charset)
      charset
    ))


;;; @ detection
;;;

(defvar charsets-mime-charset-alist
  (let ((alist
         '(((lc-ascii)                                  . us-ascii)
           ((lc-ascii lc-ltn1)                          . iso-8859-1)
           ((lc-ascii lc-ltn2)                          . iso-8859-2)
           ((lc-ascii lc-ltn3)                          . iso-8859-3)
           ((lc-ascii lc-ltn4)                          . iso-8859-4)
;;;        ((lc-ascii lc-crl)                           . iso-8859-5)
           ((lc-ascii lc-crl)                           . koi8-r)
           ((lc-ascii lc-arb)                           . iso-8859-6)
           ((lc-ascii lc-grk)                           . iso-8859-7)
           ((lc-ascii lc-hbw)                           . iso-8859-8)
           ((lc-ascii lc-ltn5)                          . iso-8859-9)
           ((lc-ascii lc-roman lc-jpold lc-jp)          . iso-2022-jp)
           ((lc-ascii lc-kr)                            . euc-kr)
           ((lc-ascii lc-cn)                            . gb2312)
           ((lc-ascii lc-big5-1 lc-big5-2)              . big5)
           ((lc-ascii lc-roman lc-ltn1 lc-grk
                      lc-jpold lc-cn lc-jp lc-kr
                      lc-jp2)                           . iso-2022-jp-2)
           ((lc-ascii lc-roman lc-ltn1 lc-grk
                      lc-jpold lc-cn lc-jp lc-kr lc-jp2
                      lc-cns1 lc-cns2)                  . iso-2022-int-1)
           ((lc-ascii lc-roman
                      lc-ltn1 lc-ltn2 lc-crl lc-grk
                      lc-jpold lc-cn lc-jp lc-kr lc-jp2
                      lc-cns1 lc-cns2 lc-cns3 lc-cns4
                      lc-cns5 lc-cns6 lc-cns7)          . iso-2022-int-1)
           ))
        dest)
    (while alist
      (catch 'not-found
        (let ((pair (car alist)))
          (setq dest
                (append dest
                        (list
                         (cons (mapcar (function
                                        (lambda (cs)
                                          (if (boundp cs)
                                              (symbol-value cs)
                                            (throw 'not-found nil)
                                            )))
                                       (car pair))
                               (cdr pair)))))))
      (setq alist (cdr alist)))
    dest))

(defvar default-mime-charset 'x-ctext
  "Default value of MIME-charset.
It is used when MIME-charset is not specified.
It must be symbol.")

(defvar default-mime-charset-for-write
  default-mime-charset
  "Default value of MIME-charset for encoding.
It is used when suitable MIME-charset is not found.
It must be symbol.")

(defun detect-mime-charset-region (start end)
  "Return MIME charset for region between START and END."
  (or (charsets-to-mime-charset
       (cons lc-ascii (find-charset-region start end)))
      default-mime-charset-for-write))


;;; @ end
;;;

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

;;; mcs-om.el ends here