;;; emu.el --- Emulation module for each Emacs variants

;; Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.

;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
;; Keywords: emulation, compatibility, NEmacs, MULE, Emacs/mule, XEmacs

;; This file is part of emu.

;; 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 'poe)

(defvar running-emacs-18 (<= emacs-major-version 18))
(defvar running-xemacs (featurep 'xemacs))

(defvar running-mule-merged-emacs (and (not (boundp 'MULE))
				       (not running-xemacs) (featurep 'mule)))
(defvar running-xemacs-with-mule (and running-xemacs (featurep 'mule)))

(defvar running-emacs-19 (and (not running-xemacs) (= emacs-major-version 19)))
(defvar running-emacs-19_29-or-later
  (or (and running-emacs-19 (>= emacs-minor-version 29))
      (and (not running-xemacs)(>= emacs-major-version 20))))

(defvar running-xemacs-19 (and running-xemacs
			       (= emacs-major-version 19)))
(defvar running-xemacs-20-or-later (and running-xemacs
					(>= emacs-major-version 20)))
(defvar running-xemacs-19_14-or-later
  (or (and running-xemacs-19 (>= emacs-minor-version 14))
      running-xemacs-20-or-later))

(cond (running-xemacs
       ;; for XEmacs
       (defvar mouse-button-1 'button1)
       (defvar mouse-button-2 'button2)
       (defvar mouse-button-3 'button3)
       )
      ((>= emacs-major-version 19)
       ;; for tm-7.106
       (defalias 'tl:make-overlay 'make-overlay)
       (defalias 'tl:overlay-put 'overlay-put)
       (defalias 'tl:overlay-buffer 'overlay-buffer)
       
       (make-obsolete 'tl:make-overlay 'make-overlay)
       (make-obsolete 'tl:overlay-put 'overlay-put)
       (make-obsolete 'tl:overlay-buffer 'overlay-buffer)
       
       ;; mouse
       (defvar mouse-button-1 [mouse-1])
       (defvar mouse-button-2 [mouse-2])
       (defvar mouse-button-3 [down-mouse-3])
       )
      (t
       ;; mouse
       (defvar mouse-button-1 nil)
       (defvar mouse-button-2 nil)
       (defvar mouse-button-3 nil)
       ))

(require 'poem)
(require 'mcharset)

(cond (running-xemacs
       (if (featurep 'mule)
	   ;; for XEmacs with MULE
	   (require 'emu-x20)
	 ;; for XEmacs without MULE
	 (require 'emu-latin1)
	 ))
      (running-mule-merged-emacs
       ;; for Emacs 20.1 and 20.2
       (require 'emu-e20)
       )
      ((boundp 'MULE)
       ;; for MULE 1.* and 2.*
       (require 'emu-mule)
       )
      ((boundp 'NEMACS)
       ;; for NEmacs and NEpoch
       (require 'emu-nemacs)
       )
      (t
       ;; for Emacs 19
       (require 'emu-latin1)
       ))


;;; @ Mule emulating aliases
;;;
;;; You should not use it.

(or (boundp '*noconv*)
    (defconst *noconv* 'binary
      "Coding-system for binary.
This constant is defined to emulate old MULE anything older than MULE 2.3.
It is obsolete, so don't use it."))


;;; @ MIME charset
;;;

(defun charsets-to-mime-charset (charsets)
  "Return MIME charset from list of charset CHARSETS.
This function refers variable `charsets-mime-charset-alist'
and `default-mime-charset'."
  (if charsets
      (or (catch 'tag
	    (let ((rest charsets-mime-charset-alist)
		  cell)
	      (while (setq cell (car rest))
		(if (catch 'not-subset
		      (let ((set1 charsets)
			    (set2 (car cell))
			    obj)
			(while set1
			  (setq obj (car set1))
			  (or (memq obj set2)
			      (throw 'not-subset nil))
			  (setq set1 (cdr set1)))
			t))
		    (throw 'tag (cdr cell)))
		(setq rest (cdr rest)))))
	  default-mime-charset)))


;;; @ Emacs 20.3 emulation
;;;

(defmacro-maybe string-as-unibyte (string)
  "Return a unibyte string with the same individual bytes as STRING.
If STRING is unibyte, the result is STRING itself.
\[Emacs 20.3 emulating macro]"
  string)

(defmacro-maybe string-as-multibyte (string)
  "Return a multibyte string with the same individual bytes as STRING.
If STRING is multibyte, the result is STRING itself.
\[Emacs 20.3 emulating macro]"
  string)


;;; @ for XEmacs 20
;;;

(or (fboundp 'char-int)
    (fset 'char-int (symbol-function 'identity))
    )
(or (fboundp 'int-char)
    (fset 'int-char (symbol-function 'identity))
    )
(or (fboundp 'char-or-char-int-p)
    (fset 'char-or-char-int-p (symbol-function 'integerp))
    )


;;; @ for text/richtext and text/enriched
;;;

(cond ((fboundp 'richtext-decode)
       ;; have richtext.el
       )
      ((or running-emacs-19_29-or-later running-xemacs-19_14-or-later)
       ;; have enriched.el
       (autoload 'richtext-decode "richtext")
       (or (assq 'text/richtext format-alist)
	   (setq format-alist
		 (cons
		  (cons 'text/richtext
			'("Extended MIME text/richtext format."
			  "Content-[Tt]ype:[ \t]*text/richtext"
			  richtext-decode richtext-encode t enriched-mode))
		  format-alist)))
       )
      (t
       ;; don't have enriched.el
       (autoload 'richtext-decode "tinyrich")
       (autoload 'enriched-decode "tinyrich")
       ))


;;; @ end
;;;

(provide 'emu)

;;; emu.el ends here