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emacs/lisp/gnus/mm-decode.el
2003-02-04 13:24:35 +00:00

854 lines
27 KiB
EmacsLisp

;;; mm-decode.el --- functions for decoding MIME things
;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
;; 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, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;;; Code:
(require 'mail-parse)
(require 'mailcap)
(require 'mm-bodies)
(eval-when-compile (require 'cl))
(eval-and-compile
(autoload 'mm-inline-partial "mm-partial")
(autoload 'mm-insert-inline "mm-view"))
(defgroup mime-display ()
"Display of MIME in mail and news articles."
:link '(custom-manual "(emacs-mime)Customization")
:version "21.1"
:group 'mail
:group 'news
:group 'multimedia)
;;; Convenience macros.
(defmacro mm-handle-buffer (handle)
`(nth 0 ,handle))
(defmacro mm-handle-type (handle)
`(nth 1 ,handle))
(defsubst mm-handle-media-type (handle)
(if (stringp (car handle))
(car handle)
(car (mm-handle-type handle))))
(defsubst mm-handle-media-supertype (handle)
(car (split-string (mm-handle-media-type handle) "/")))
(defsubst mm-handle-media-subtype (handle)
(cadr (split-string (mm-handle-media-type handle) "/")))
(defmacro mm-handle-encoding (handle)
`(nth 2 ,handle))
(defmacro mm-handle-undisplayer (handle)
`(nth 3 ,handle))
(defmacro mm-handle-set-undisplayer (handle function)
`(setcar (nthcdr 3 ,handle) ,function))
(defmacro mm-handle-disposition (handle)
`(nth 4 ,handle))
(defmacro mm-handle-description (handle)
`(nth 5 ,handle))
(defmacro mm-handle-cache (handle)
`(nth 6 ,handle))
(defmacro mm-handle-set-cache (handle contents)
`(setcar (nthcdr 6 ,handle) ,contents))
(defmacro mm-handle-id (handle)
`(nth 7 ,handle))
(defmacro mm-make-handle (&optional buffer type encoding undisplayer
disposition description cache
id)
`(list ,buffer ,type ,encoding ,undisplayer
,disposition ,description ,cache ,id))
(defcustom mm-inline-media-tests
'(("image/jpeg"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'jpeg handle)))
("image/png"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'png handle)))
("image/gif"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'gif handle)))
("image/tiff"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'tiff handle)) )
("image/xbm"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'xbm handle)))
("image/x-xbitmap"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'xbm handle)))
("image/xpm"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'xpm handle)))
("image/x-pixmap"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'xpm handle)))
("image/bmp"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'bmp handle)))
("image/x-portable-bitmap"
mm-inline-image
(lambda (handle)
(mm-valid-and-fit-image-p 'pbm handle)))
("text/plain" mm-inline-text identity)
("text/enriched" mm-inline-text identity)
("text/richtext" mm-inline-text identity)
("text/x-patch" mm-display-patch-inline
(lambda (handle)
(locate-library "diff-mode")))
("application/emacs-lisp" mm-display-elisp-inline identity)
("text/html"
mm-inline-text
(lambda (handle)
(locate-library "w3")))
("text/x-vcard"
mm-inline-text
(lambda (handle)
(or (featurep 'vcard)
(locate-library "vcard"))))
("message/delivery-status" mm-inline-text identity)
("message/rfc822" mm-inline-message identity)
("message/partial" mm-inline-partial identity)
("text/.*" mm-inline-text identity)
("audio/wav" mm-inline-audio
(lambda (handle)
(and (or (featurep 'nas-sound) (featurep 'native-sound))
(device-sound-enabled-p))))
("audio/au"
mm-inline-audio
(lambda (handle)
(and (or (featurep 'nas-sound) (featurep 'native-sound))
(device-sound-enabled-p))))
("application/pgp-signature" ignore identity)
("multipart/alternative" ignore identity)
("multipart/mixed" ignore identity)
("multipart/related" ignore identity))
"Alist of media types/tests saying whether types can be displayed inline."
:type '(repeat (list (string :tag "MIME type")
(function :tag "Display function")
(function :tag "Display test")))
:group 'mime-display)
(defcustom mm-inlined-types
'("image/.*" "text/.*" "message/delivery-status" "message/rfc822"
"message/partial" "application/emacs-lisp"
"application/pgp-signature")
"List of media types that are to be displayed inline."
:type '(repeat string)
:group 'mime-display)
(defcustom mm-automatic-display
'("text/plain" "text/enriched" "text/richtext" "text/html"
"text/x-vcard" "image/.*" "message/delivery-status" "multipart/.*"
"message/rfc822" "text/x-patch" "application/pgp-signature"
"application/emacs-lisp")
"A list of MIME types to be displayed automatically."
:type '(repeat string)
:group 'mime-display)
(defcustom mm-attachment-override-types '("text/x-vcard")
"Types to have \"attachment\" ignored if they can be displayed inline."
:type '(repeat string)
:group 'mime-display)
(defcustom mm-inline-override-types nil
"Types to be treated as attachments even if they can be displayed inline."
:type '(repeat string)
:group 'mime-display)
(defcustom mm-automatic-external-display nil
"List of MIME type regexps that will be displayed externally automatically."
:type '(repeat string)
:group 'mime-display)
(defcustom mm-discouraged-alternatives nil
"List of MIME types that are discouraged when viewing multipart/alternative.
Viewing agents are supposed to view the last possible part of a message,
as that is supposed to be the richest. However, users may prefer other
types instead, and this list says what types are most unwanted. If,
for instance, text/html parts are very unwanted, and text/richtext are
somewhat unwanted, then the value of this variable should be set
to:
(\"text/html\" \"text/richtext\")"
:type '(repeat string)
:group 'mime-display)
(defvar mm-tmp-directory
(cond ((fboundp 'temp-directory) (temp-directory))
((boundp 'temporary-file-directory) temporary-file-directory)
("/tmp/"))
"Where mm will store its temporary files.")
(defcustom mm-inline-large-images nil
"If non-nil, then all images fit in the buffer."
:type 'boolean
:group 'mime-display)
;;; Internal variables.
(defvar mm-dissection-list nil)
(defvar mm-last-shell-command "")
(defvar mm-content-id-alist nil)
;; According to RFC2046, in particular, in a digest, the default
;; Content-Type value for a body part is changed from "text/plain" to
;; "message/rfc822".
(defvar mm-dissect-default-type "text/plain")
(defvar mm-viewer-completion-map
(let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
(set-keymap-parent map minibuffer-local-completion-map)
map)
"Keymap for input viewer with completion.")
;; Should we bind other key to minibuffer-complete-word?
(define-key mm-viewer-completion-map " " 'self-insert-command)
;;; The functions.
(defun mm-dissect-buffer (&optional no-strict-mime)
"Dissect the current buffer and return a list of MIME handles."
(save-excursion
(let (ct ctl type subtype cte cd description id result)
(save-restriction
(mail-narrow-to-head)
(when (or no-strict-mime
(mail-fetch-field "mime-version"))
(setq ct (mail-fetch-field "content-type")
ctl (ignore-errors (mail-header-parse-content-type ct))
cte (mail-fetch-field "content-transfer-encoding")
cd (mail-fetch-field "content-disposition")
description (mail-fetch-field "content-description")
id (mail-fetch-field "content-id"))))
(when cte
(setq cte (mail-header-strip cte)))
(if (or (not ctl)
(not (string-match "/" (car ctl))))
(mm-dissect-singlepart
(list mm-dissect-default-type)
(and cte (intern (downcase (mail-header-remove-whitespace
(mail-header-remove-comments
cte)))))
no-strict-mime
(and cd (ignore-errors (mail-header-parse-content-disposition cd)))
description)
(setq type (split-string (car ctl) "/"))
(setq subtype (cadr type)
type (pop type))
(setq
result
(cond
((equal type "multipart")
(let ((mm-dissect-default-type (if (equal subtype "digest")
"message/rfc822"
"text/plain")))
(cons (car ctl) (mm-dissect-multipart ctl))))
(t
(mm-dissect-singlepart
ctl
(and cte (intern (downcase (mail-header-remove-whitespace
(mail-header-remove-comments
cte)))))
no-strict-mime
(and cd (ignore-errors (mail-header-parse-content-disposition cd)))
description id))))
(when id
(when (string-match " *<\\(.*\\)> *" id)
(setq id (match-string 1 id)))
(push (cons id result) mm-content-id-alist))
result))))
(defun mm-dissect-singlepart (ctl cte &optional force cdl description id)
(when (or force
(if (equal "text/plain" (car ctl))
(assoc 'format ctl)
t))
(let ((res (mm-make-handle
(mm-copy-to-buffer) ctl cte nil cdl description nil id)))
(push (car res) mm-dissection-list)
res)))
(defun mm-remove-all-parts ()
"Remove all MIME handles."
(interactive)
(mapcar 'mm-remove-part mm-dissection-list)
(setq mm-dissection-list nil))
(defun mm-dissect-multipart (ctl)
(goto-char (point-min))
(let* ((boundary (concat "\n--" (mail-content-type-get ctl 'boundary)))
(close-delimiter (concat (regexp-quote boundary) "--[ \t]*$"))
start parts
(end (save-excursion
(goto-char (point-max))
(if (re-search-backward close-delimiter nil t)
(match-beginning 0)
(point-max)))))
(setq boundary (concat (regexp-quote boundary) "[ \t]*$"))
(while (and (< (point) end) (re-search-forward boundary end t))
(goto-char (match-beginning 0))
(when start
(save-excursion
(save-restriction
(narrow-to-region start (point))
(setq parts (nconc (list (mm-dissect-buffer t)) parts)))))
(forward-line 2)
(setq start (point)))
(when (and start (< start end))
(save-excursion
(save-restriction
(narrow-to-region start end)
(setq parts (nconc (list (mm-dissect-buffer t)) parts)))))
(nreverse parts)))
(defun mm-copy-to-buffer ()
"Copy the contents of the current buffer to a fresh buffer."
(save-excursion
(let ((obuf (current-buffer))
beg)
(goto-char (point-min))
(search-forward-regexp "^\n" nil t)
(setq beg (point))
(set-buffer (generate-new-buffer " *mm*"))
(insert-buffer-substring obuf beg)
(current-buffer))))
(defun mm-display-part (handle &optional no-default)
"Display the MIME part represented by HANDLE.
Returns nil if the part is removed; inline if displayed inline;
external if displayed external."
(save-excursion
(mailcap-parse-mailcaps)
(if (mm-handle-displayed-p handle)
(mm-remove-part handle)
(let* ((type (mm-handle-media-type handle))
(method (mailcap-mime-info type)))
(if (mm-inlined-p handle)
(progn
(forward-line 1)
(mm-display-inline handle)
'inline)
(when (or method
(not no-default))
(if (and (not method)
(equal "text" (car (split-string type))))
(progn
(forward-line 1)
(mm-insert-inline handle (mm-get-part handle))
'inline)
(mm-display-external
handle (or method 'mailcap-save-binary-file)))))))))
(defun mm-display-external (handle method)
"Display HANDLE using METHOD."
(let ((outbuf (current-buffer)))
(mm-with-unibyte-buffer
(if (functionp method)
(let ((cur (current-buffer)))
(if (eq method 'mailcap-save-binary-file)
(progn
(set-buffer (generate-new-buffer " *mm*"))
(setq method nil))
(mm-insert-part handle)
(let ((win (get-buffer-window cur t)))
(when win
(select-window win)))
(switch-to-buffer (generate-new-buffer " *mm*")))
(mm-set-buffer-file-coding-system mm-binary-coding-system)
(insert-buffer-substring cur)
(goto-char (point-min))
(message "Viewing with %s" method)
(let ((mm (current-buffer))
(non-viewer (assq 'non-viewer
(mailcap-mime-info
(mm-handle-media-type handle) t))))
(unwind-protect
(if method
(funcall method)
(mm-save-part handle))
(when (and (not non-viewer)
method)
(mm-handle-set-undisplayer handle mm)))))
;; The function is a string to be executed.
(mm-insert-part handle)
(let* ((dir (mm-make-temp-file
(expand-file-name "emm." mm-tmp-directory) 'dir))
(filename (mail-content-type-get
(mm-handle-disposition handle) 'filename))
(mime-info (mailcap-mime-info
(mm-handle-media-type handle) t))
(needsterm (or (assoc "needsterm" mime-info)
(assoc "needsterminal" mime-info)))
(copiousoutput (assoc "copiousoutput" mime-info))
file buffer)
;; We create a private sub-directory where we store our files.
(set-file-modes dir 448)
(if filename
(setq file (expand-file-name (file-name-nondirectory filename)
dir))
(setq file (mm-make-temp-file (expand-file-name "mm." dir))))
(let ((coding-system-for-write mm-binary-coding-system))
(write-region (point-min) (point-max) file nil 'nomesg))
(message "Viewing with %s" method)
(cond (needsterm
(unwind-protect
(start-process "*display*" nil
"xterm"
"-e" shell-file-name
shell-command-switch
(mm-mailcap-command
method file (mm-handle-type handle)))
(mm-handle-set-undisplayer handle (cons file buffer)))
(message "Displaying %s..." (format method file))
'external)
(copiousoutput
(with-current-buffer outbuf
(forward-line 1)
(mm-insert-inline
handle
(unwind-protect
(progn
(call-process shell-file-name nil
(setq buffer
(generate-new-buffer "*mm*"))
nil
shell-command-switch
(mm-mailcap-command
method file (mm-handle-type handle)))
(if (buffer-live-p buffer)
(save-excursion
(set-buffer buffer)
(buffer-string))))
(progn
(ignore-errors (delete-file file))
(ignore-errors (delete-directory
(file-name-directory file)))
(ignore-errors (kill-buffer buffer))))))
'inline)
(t
(unwind-protect
(start-process "*display*"
(setq buffer
(generate-new-buffer "*mm*"))
shell-file-name
shell-command-switch
(mm-mailcap-command
method file (mm-handle-type handle)))
(mm-handle-set-undisplayer handle (cons file buffer)))
(message "Displaying %s..." (format method file))
'external)))))))
(defun mm-mailcap-command (method file type-list)
(let ((ctl (cdr type-list))
(beg 0)
(uses-stdin t)
out sub total)
(while (string-match "%{\\([^}]+\\)}\\|%s\\|%t\\|%%" method beg)
(push (substring method beg (match-beginning 0)) out)
(setq beg (match-end 0)
total (match-string 0 method)
sub (match-string 1 method))
(cond
((string= total "%%")
(push "%" out))
((string= total "%s")
(setq uses-stdin nil)
(push (mm-quote-arg file) out))
((string= total "%t")
(push (mm-quote-arg (car type-list)) out))
(t
(push (mm-quote-arg (or (cdr (assq (intern sub) ctl)) "")) out))))
(push (substring method beg (length method)) out)
(if uses-stdin
(progn
(push "<" out)
(push (mm-quote-arg file) out)))
(mapconcat 'identity (nreverse out) "")))
(defun mm-remove-parts (handles)
"Remove the displayed MIME parts represented by HANDLES."
(if (and (listp handles)
(bufferp (car handles)))
(mm-remove-part handles)
(let (handle)
(while (setq handle (pop handles))
(cond
((stringp handle)
;; Do nothing.
)
((and (listp handle)
(stringp (car handle)))
(mm-remove-parts (cdr handle)))
(t
(mm-remove-part handle)))))))
(defun mm-destroy-parts (handles)
"Remove the displayed MIME parts represented by HANDLES."
(if (and (listp handles)
(bufferp (car handles)))
(mm-destroy-part handles)
(let (handle)
(while (setq handle (pop handles))
(cond
((stringp handle)
;; Do nothing.
)
((and (listp handle)
(stringp (car handle)))
(mm-destroy-parts (cdr handle)))
(t
(mm-destroy-part handle)))))))
(defun mm-remove-part (handle)
"Remove the displayed MIME part represented by HANDLE."
(when (listp handle)
(let ((object (mm-handle-undisplayer handle)))
(ignore-errors
(cond
;; Internally displayed part.
((mm-annotationp object)
(delete-annotation object))
((or (functionp object)
(and (listp object)
(eq (car object) 'lambda)))
(funcall object))
;; Externally displayed part.
((consp object)
(ignore-errors (delete-file (car object)))
(ignore-errors (delete-directory (file-name-directory (car object))))
(ignore-errors (kill-buffer (cdr object))))
((bufferp object)
(when (buffer-live-p object)
(kill-buffer object)))))
(mm-handle-set-undisplayer handle nil))))
(defun mm-display-inline (handle)
(let* ((type (mm-handle-media-type handle))
(function (cadr (mm-assoc-string-match mm-inline-media-tests type))))
(funcall function handle)
(goto-char (point-min))))
(defun mm-assoc-string-match (alist type)
(dolist (elem alist)
(when (string-match (car elem) type)
(return elem))))
(defun mm-inlinable-p (handle)
"Say whether HANDLE can be displayed inline."
(let ((alist mm-inline-media-tests)
(type (mm-handle-media-type handle))
test)
(while alist
(when (string-match (caar alist) type)
(setq test (caddar alist)
alist nil)
(setq test (funcall test handle)))
(pop alist))
test))
(defun mm-automatic-display-p (handle)
"Say whether the user wants HANDLE to be displayed automatically."
(let ((methods mm-automatic-display)
(type (mm-handle-media-type handle))
method result)
(while (setq method (pop methods))
(when (and (not (mm-inline-override-p handle))
(string-match method type)
(mm-inlinable-p handle))
(setq result t
methods nil)))
result))
(defun mm-inlined-p (handle)
"Say whether the user wants HANDLE to be displayed automatically."
(let ((methods mm-inlined-types)
(type (mm-handle-media-type handle))
method result)
(while (setq method (pop methods))
(when (and (not (mm-inline-override-p handle))
(string-match method type)
(mm-inlinable-p handle))
(setq result t
methods nil)))
result))
(defun mm-attachment-override-p (handle)
"Say whether HANDLE should have attachment behavior overridden."
(let ((types mm-attachment-override-types)
(type (mm-handle-media-type handle))
ty)
(catch 'found
(while (setq ty (pop types))
(when (and (string-match ty type)
(mm-inlinable-p handle))
(throw 'found t))))))
(defun mm-inline-override-p (handle)
"Say whether HANDLE should have inline behavior overridden."
(let ((types mm-inline-override-types)
(type (mm-handle-media-type handle))
ty)
(catch 'found
(while (setq ty (pop types))
(when (string-match ty type)
(throw 'found t))))))
(defun mm-automatic-external-display-p (type)
"Return the user-defined method for TYPE."
(let ((methods mm-automatic-external-display)
method result)
(while (setq method (pop methods))
(when (string-match method type)
(setq result t
methods nil)))
result))
(defun mm-destroy-part (handle)
"Destroy the data structures connected to HANDLE."
(when (listp handle)
(mm-remove-part handle)
(when (buffer-live-p (mm-handle-buffer handle))
(kill-buffer (mm-handle-buffer handle)))))
(defun mm-handle-displayed-p (handle)
"Say whether HANDLE is displayed or not."
(mm-handle-undisplayer handle))
;;;
;;; Functions for outputting parts
;;;
(defun mm-get-part (handle)
"Return the contents of HANDLE as a string."
(mm-with-unibyte-buffer
(mm-insert-part handle)
(buffer-string)))
(defun mm-insert-part (handle)
"Insert the contents of HANDLE in the current buffer."
(let ((cur (current-buffer)))
(save-excursion
(if (member (mm-handle-media-supertype handle) '("text" "message"))
(with-temp-buffer
(insert-buffer-substring (mm-handle-buffer handle))
(mm-decode-content-transfer-encoding
(mm-handle-encoding handle)
(mm-handle-media-type handle))
(let ((temp (current-buffer)))
(set-buffer cur)
(insert-buffer-substring temp)))
(mm-with-unibyte-buffer
(insert-buffer-substring (mm-handle-buffer handle))
(mm-decode-content-transfer-encoding
(mm-handle-encoding handle)
(mm-handle-media-type handle))
(let ((temp (current-buffer)))
(set-buffer cur)
(insert-buffer-substring temp)))))))
(defvar mm-default-directory nil)
(defun mm-save-part (handle)
"Write HANDLE to a file."
(let* ((name (mail-content-type-get (mm-handle-type handle) 'name))
(filename (mail-content-type-get
(mm-handle-disposition handle) 'filename))
file)
(when filename
(setq filename (file-name-nondirectory filename)))
(setq file
(read-file-name "Save MIME part to: "
(expand-file-name
(or filename name "")
(or mm-default-directory default-directory))))
(setq mm-default-directory (file-name-directory file))
(when (or (not (file-exists-p file))
(yes-or-no-p (format "File %s already exists; overwrite? "
file)))
(mm-save-part-to-file handle file))))
(defun mm-save-part-to-file (handle file)
(mm-with-unibyte-buffer
(mm-insert-part handle)
(let ((coding-system-for-write 'binary)
;; Don't re-compress .gz & al. Arguably we should make
;; `file-name-handler-alist' nil, but that would chop
;; ange-ftp, which is reasonable to use here.
(inhibit-file-name-operation 'write-region)
(inhibit-file-name-handlers
(cons 'jka-compr-handler inhibit-file-name-handlers)))
(write-region (point-min) (point-max) file))))
(defun mm-pipe-part (handle)
"Pipe HANDLE to a process."
(let* ((name (mail-content-type-get (mm-handle-type handle) 'name))
(command
(read-string "Shell command on MIME part: " mm-last-shell-command)))
(mm-with-unibyte-buffer
(mm-insert-part handle)
(shell-command-on-region (point-min) (point-max) command nil))))
(defun mm-interactively-view-part (handle)
"Display HANDLE using METHOD."
(let* ((type (mm-handle-media-type handle))
(methods
(mapcar (lambda (i) (list (cdr (assoc 'viewer i))))
(mailcap-mime-info type 'all)))
(method (let ((minibuffer-local-completion-map
mm-viewer-completion-map))
(completing-read "Viewer: " methods))))
(when (string= method "")
(error "No method given"))
(if (string-match "^[^% \t]+$" method)
(setq method (concat method " %s")))
(mm-display-external handle method)))
(defun mm-preferred-alternative (handles &optional preferred)
"Say which of HANDLES are preferred."
(let ((prec (if preferred (list preferred)
(mm-preferred-alternative-precedence handles)))
p h result type handle)
(while (setq p (pop prec))
(setq h handles)
(while h
(setq handle (car h))
(setq type (mm-handle-media-type handle))
(when (and (equal p type)
(mm-automatic-display-p handle)
(or (stringp (car handle))
(not (mm-handle-disposition handle))
(equal (car (mm-handle-disposition handle))
"inline")))
(setq result handle
h nil
prec nil))
(pop h)))
result))
(defun mm-preferred-alternative-precedence (handles)
"Return the precedence based on HANDLES and `mm-discouraged-alternatives'."
(let ((seq (nreverse (mapcar #'mm-handle-media-type
handles))))
(dolist (disc (reverse mm-discouraged-alternatives))
(dolist (elem (copy-sequence seq))
(when (string-match disc elem)
(setq seq (nconc (delete elem seq) (list elem))))))
seq))
(defun mm-get-content-id (id)
"Return the handle(s) referred to by ID."
(cdr (assoc id mm-content-id-alist)))
(defun mm-get-image (handle)
"Return an image instance based on HANDLE."
(let ((type (mm-handle-media-subtype handle))
spec)
;; Allow some common translations.
(setq type
(cond
((equal type "x-pixmap")
"xpm")
((equal type "x-xbitmap")
"xbm")
((equal type "x-portable-bitmap")
"pbm")
(t type)))
(or (mm-handle-cache handle)
(mm-with-unibyte-buffer
(mm-insert-part handle)
(prog1
(setq spec
(ignore-errors
;; Avoid testing `make-glyph' since W3 may define
;; a bogus version of it.
(if (fboundp 'create-image)
(create-image (buffer-string) (intern type) 'data-p)
(cond
((equal type "xbm")
;; xbm images require special handling, since
;; the only way to create glyphs from these
;; (without a ton of work) is to write them
;; out to a file, and then create a file
;; specifier.
(let ((file (mm-make-temp-file
(expand-file-name "emm.xbm"
mm-tmp-directory))))
(unwind-protect
(progn
(write-region (point-min) (point-max) file)
(make-glyph (list (cons 'x file))))
(ignore-errors
(delete-file file)))))
(t
(make-glyph
(vector (intern type) :data (buffer-string))))))))
(mm-handle-set-cache handle spec))))))
(defun mm-image-fit-p (handle)
"Say whether the image in HANDLE will fit the current window."
(let ((image (mm-get-image handle)))
(if (fboundp 'glyph-width)
;; XEmacs' glyphs can actually tell us about their width, so
;; lets be nice and smart about them.
(or mm-inline-large-images
(and (< (glyph-width image) (window-pixel-width))
(< (glyph-height image) (window-pixel-height))))
(let* ((size (image-size image))
(w (car size))
(h (cdr size)))
(or mm-inline-large-images
(and (< h (1- (window-height))) ; Don't include mode line.
(< w (window-width))))))))
(defun mm-valid-image-format-p (format)
"Say whether FORMAT can be displayed natively by Emacs."
(cond
;; Handle XEmacs
((fboundp 'valid-image-instantiator-format-p)
(valid-image-instantiator-format-p format))
;; Handle Emacs 21
((fboundp 'image-type-available-p)
(and (display-graphic-p)
(image-type-available-p format)))
;; Nobody else can do images yet.
(t
nil)))
(defun mm-valid-and-fit-image-p (format handle)
"Say whether FORMAT can be displayed natively and HANDLE fits the window."
(and (mm-valid-image-format-p format)
(mm-image-fit-p handle)))
(provide 'mm-decode)
;;; mm-decode.el ends here