1 ;;; enriched.el --- read and save files in text/enriched format
3 ;; Copyright (c) 1994, 1995, 1996, 2002, 2004 Free Software Foundation, Inc.
5 ;; Author: Boris Goldowsky <boris@gnu.org>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;; This file implements reading, editing, and saving files with
28 ;; text-properties such as faces, levels of indentation, and true line
29 ;; breaks distinguished from newlines just used to fit text into the window.
31 ;; The file format used is the MIME text/enriched format, which is a
32 ;; standard format defined in internet RFC 1563. All standard annotations
33 ;; are supported except for <smaller> and <bigger>, which are currently not
34 ;; possible to display.
36 ;; A separate file, enriched.doc, contains further documentation and other
37 ;; important information about this code. It also serves as an example
38 ;; file in text/enriched format. It should be in the etc directory of your
39 ;; emacs distribution.
46 ;;; Variables controlling the display
49 (defgroup enriched nil
50 "Read and save files in text/enriched format"
53 (defcustom enriched-verbose t
54 "*If non-nil, give status messages when reading and writing files."
59 ;;; Set up faces & display table
62 ;; Emacs doesn't have a "fixed" face by default, since all faces currently
63 ;; have to be fixed-width. So we just pick one that looks different from the
67 "Face used for text that must be shown in fixed width.
68 Currently, emacs can only display fixed-width fonts, but this may change.
69 This face is used for text specifically marked as fixed-width, for example
70 in text/enriched files."
74 '((t (:slant italic)))
75 "Face used for text that is an excerpt from another document.
76 This is used in Enriched mode for text explicitly marked as an excerpt."
79 (defconst enriched-display-table (or (copy-sequence standard-display-table)
80 (make-display-table)))
81 (aset enriched-display-table ?\f (make-vector (1- (frame-width)) ?-))
83 (defconst enriched-par-props '(left-margin right-margin justification)
84 "Text-properties that usually apply to whole paragraphs.
85 These are set front-sticky everywhere except at hard newlines.")
88 ;;; Variables controlling the file format
91 (defconst enriched-initial-annotation
93 (format "Content-Type: text/enriched\nText-Width: %d\n\n"
95 "What to insert at the start of a text/enriched file.
96 If this is a string, it is inserted. If it is a list, it should be a lambda
97 expression, which is evaluated to get the string to insert.")
99 (defconst enriched-annotation-format "<%s%s>"
100 "General format of enriched-text annotations.")
102 (defconst enriched-annotation-regexp "<\\(/\\)?\\([-A-Za-z0-9]+\\)>"
103 "Regular expression matching enriched-text annotations.")
105 (defvar enriched-translations
106 '((face (bold-italic "bold" "italic")
109 (underline "underline")
113 (nil enriched-encode-other-face))
114 (left-margin (4 "indent"))
115 (right-margin (4 "indentright"))
116 (justification (none "nofill")
121 (PARAMETER (t "param")) ; Argument of preceding annotation
122 ;; The following are not part of the standard:
123 (FUNCTION (enriched-decode-foreground "x-color")
124 (enriched-decode-background "x-bg-color")
125 (enriched-decode-display-prop "x-display"))
126 (read-only (t "x-read-only"))
127 (display (nil enriched-handle-display-prop))
128 (unknown (nil format-annotate-value))
129 ; (font-size (2 "bigger") ; unimplemented
132 "List of definitions of text/enriched annotations.
133 See `format-annotate-region' and `format-deannotate-region' for the definition
136 (defconst enriched-ignore
137 '(front-sticky rear-nonsticky hard)
138 "Properties that are OK to ignore when saving text/enriched files.
139 Any property that is neither on this list nor dealt with by
140 `enriched-translations' will generate a warning.")
142 ;;; Internal variables
144 (defcustom enriched-mode-hook nil
145 "Hook run after entering/leaving Enriched mode.
146 If you set variables in this hook, you should arrange for them to be restored
147 to their old values if you leave Enriched mode. One way to do this is to add
148 them and their old values to `enriched-old-bindings'."
152 (defvar enriched-old-bindings nil
153 "Store old variable values that we change when entering mode.
154 The value is a list of \(VAR VALUE VAR VALUE...).")
155 (make-variable-buffer-local 'enriched-old-bindings)
157 ;; The next variable is buffer local if and only if Enriched mode is
158 ;; enabled. The buffer local value records whether
159 ;; `default-text-properties' should remain buffer local when disabling
160 ;; Enriched mode. For technical reasons, the default value should be t.
161 (defvar enriched-default-text-properties-local-flag t)
163 ;; Technical internal variable. Bound to t if `enriched-mode' is
164 ;; being rerun by a major mode to allow it to restore buffer-local
165 ;; variables and to correctly update `enriched-old-bindings'.
166 (defvar enriched-rerun-flag nil)
172 (put 'enriched-mode 'permanent-local t)
174 (define-minor-mode enriched-mode
175 "Minor mode for editing text/enriched files.
176 These are files with embedded formatting information in the MIME standard
177 text/enriched format.
178 Turning the mode on or off runs `enriched-mode-hook'.
180 More information about Enriched mode is available in the file
181 etc/enriched.doc in the Emacs distribution directory.
185 \\{enriched-mode-map}"
187 (cond ((null enriched-mode)
189 (setq buffer-file-format (delq 'text/enriched buffer-file-format))
190 ;; restore old variable values
191 (while enriched-old-bindings
192 (set (pop enriched-old-bindings) (pop enriched-old-bindings)))
193 (unless enriched-default-text-properties-local-flag
194 (kill-local-variable 'default-text-properties))
195 (kill-local-variable 'enriched-default-text-properties-local-flag)
196 (unless use-hard-newlines (use-hard-newlines 0)))
198 ((and (memq 'text/enriched buffer-file-format)
199 (not enriched-rerun-flag))
200 ;; Mode already on; do nothing.
204 (add-to-list 'buffer-file-format 'text/enriched)
205 ;; Save old variable values before we change them.
206 ;; These will be restored if we exit Enriched mode.
207 (setq enriched-old-bindings
208 (list 'buffer-display-table buffer-display-table
209 'default-text-properties default-text-properties
210 'use-hard-newlines use-hard-newlines))
211 (make-local-variable 'enriched-default-text-properties-local-flag)
212 (setq enriched-default-text-properties-local-flag
213 (local-variable-p 'default-text-properties))
214 (make-local-variable 'default-text-properties)
215 (setq buffer-display-table enriched-display-table)
216 (use-hard-newlines 1 (if enriched-rerun-flag 'never nil))
217 (let ((sticky (plist-get default-text-properties 'front-sticky))
218 (p enriched-par-props))
220 (add-to-list 'sticky x))
222 (setq default-text-properties
223 (plist-put default-text-properties
224 'front-sticky sticky)))))))
226 (defun enriched-before-change-major-mode ()
228 (while enriched-old-bindings
229 (set (pop enriched-old-bindings) (pop enriched-old-bindings)))))
231 (add-hook 'change-major-mode-hook 'enriched-before-change-major-mode)
233 (defun enriched-after-change-major-mode ()
235 (let ((enriched-rerun-flag t))
238 (add-hook 'after-change-major-mode-hook 'enriched-after-change-major-mode)
244 (defvar enriched-mode-map nil
245 "Keymap for Enriched mode.")
247 (if (null enriched-mode-map)
248 (fset 'enriched-mode-map (setq enriched-mode-map (make-sparse-keymap))))
250 (if (not (assq 'enriched-mode minor-mode-map-alist))
251 (setq minor-mode-map-alist
252 (cons (cons 'enriched-mode enriched-mode-map)
253 minor-mode-map-alist)))
255 (define-key enriched-mode-map "\C-a" 'beginning-of-line-text)
256 (define-key enriched-mode-map "\C-m" 'reindent-then-newline-and-indent)
257 (define-key enriched-mode-map "\C-j" 'reindent-then-newline-and-indent)
258 (define-key enriched-mode-map "\M-j" 'facemenu-justification-menu)
259 (define-key enriched-mode-map "\M-S" 'set-justification-center)
260 (define-key enriched-mode-map "\C-x\t" 'increase-left-margin)
261 (define-key enriched-mode-map "\C-c\C-l" 'set-left-margin)
262 (define-key enriched-mode-map "\C-c\C-r" 'set-right-margin)
265 ;;; Some functions dealing with text-properties, especially indentation
268 (defun enriched-map-property-regions (prop func &optional from to)
269 "Apply a function to regions of the buffer based on a text property.
270 For each contiguous region of the buffer for which the value of PROPERTY is
271 eq, the FUNCTION will be called. Optional arguments FROM and TO specify the
272 region over which to scan.
274 The specified function receives three arguments: the VALUE of the property in
275 the region, and the START and END of each region."
278 (if to (narrow-to-region (point-min) to))
279 (goto-char (or from (point-min)))
280 (let ((begin (point))
282 (marker (make-marker))
283 (val (get-text-property (point) prop)))
284 (while (setq end (text-property-not-all begin (point-max) prop val))
285 (move-marker marker end)
286 (funcall func val begin (marker-position marker))
287 (setq begin (marker-position marker)
288 val (get-text-property marker prop)))
289 (if (< begin (point-max))
290 (funcall func val begin (point-max)))))))
292 (put 'enriched-map-property-regions 'lisp-indent-hook 1)
294 (defun enriched-insert-indentation (&optional from to)
295 "Indent and justify each line in the region."
298 (if to (narrow-to-region (point-min) to))
299 (goto-char (or from (point-min)))
300 (if (not (bolp)) (forward-line 1))
303 nil ; skip blank lines
304 (indent-to (current-left-margin))
305 (justify-current-line t nil t))
313 (defun enriched-encode (from to orig-buf)
314 (if enriched-verbose (message "Enriched: encoding document..."))
315 (let ((inhibit-read-only t))
317 (narrow-to-region from to)
318 (delete-to-left-margin)
321 (format-replace-strings '(("<" . "<<")))
322 (format-insert-annotations
323 (format-annotate-region from (point-max) enriched-translations
324 'enriched-make-annotation enriched-ignore))
326 (insert (if (stringp enriched-initial-annotation)
327 enriched-initial-annotation
329 ;; Eval this in the buffer we are annotating. This
330 ;; fixes a bug which was saving incorrect File-Width
331 ;; information, since we were looking at local
332 ;; variables in the wrong buffer.
333 (if orig-buf (set-buffer orig-buf))
334 (funcall enriched-initial-annotation))))
335 (enriched-map-property-regions 'hard
337 (if (and v (= ?\n (char-after b)))
338 (progn (goto-char b) (insert "\n"))))
340 (if enriched-verbose (message nil))
344 (defun enriched-make-annotation (internal-ann positive)
345 "Format an annotation INTERNAL-ANN.
346 INTERNAL-ANN may be a string, for a flag, or a list of the form (PARAM VALUE).
347 If POSITIVE is non-nil, this is the opening annotation;
348 if nil, the matching close."
349 (cond ((stringp internal-ann)
350 (format enriched-annotation-format (if positive "" "/") internal-ann))
351 ;; Otherwise it is an annotation with parameters, represented as a list
353 (let ((item (car internal-ann))
354 (params (cdr internal-ann)))
355 (concat (format enriched-annotation-format "" item)
356 (mapconcat (lambda (i) (concat "<param>" i "</param>"))
358 (t (format enriched-annotation-format "/" (car internal-ann)))))
360 (defun enriched-encode-other-face (old new)
361 "Generate annotations for random face change.
362 One annotation each for foreground color, background color, italic, etc."
363 (cons (and old (enriched-face-ans old))
364 (and new (enriched-face-ans new))))
366 (defun enriched-face-ans (face)
367 "Return annotations specifying FACE.
368 FACE may be a list of faces instead of a single face;
369 it can also be anything allowed as an element of a list
370 which can be the value of the `face' text property."
371 (cond ((and (consp face) (eq (car face) 'foreground-color))
372 (list (list "x-color" (cdr face))))
373 ((and (consp face) (eq (car face) 'background-color))
374 (list (list "x-bg-color" (cdr face))))
375 ((and (listp face) (eq (car face) :foreground))
376 (list (list "x-color" (cadr face))))
377 ((and (listp face) (eq (car face) :background))
378 (list (list "x-bg-color" (cadr face))))
380 (apply 'append (mapcar 'enriched-face-ans face)))
381 ((let* ((fg (face-attribute face :foreground))
382 (bg (face-attribute face :background))
383 (props (face-font face t))
384 (ans (cdr (format-annotate-single-property-change
385 'face nil props enriched-translations))))
386 (unless (eq fg 'unspecified)
387 (setq ans (cons (list "x-color" fg) ans)))
388 (unless (eq bg 'unspecified)
389 (setq ans (cons (list "x-bg-color" bg) ans)))
397 (defun enriched-decode (from to)
398 (if enriched-verbose (message "Enriched: decoding document..."))
399 (use-hard-newlines 1 'never)
402 (narrow-to-region from to)
406 (let ((file-width (enriched-get-file-width)))
407 (enriched-remove-header)
409 ;; Deal with newlines
410 (while (search-forward-regexp "\n\n+" nil t)
411 (if (current-justification)
413 (set-hard-newline-properties (match-beginning 0) (point)))
415 ;; Translate annotations
416 (format-deannotate-region from (point-max) enriched-translations
417 'enriched-next-annotation)
419 ;; Indent or fill the buffer
420 (cond (file-width ; File was filled to this width
421 (setq fill-column file-width)
422 (if enriched-verbose (message "Indenting..."))
423 (enriched-insert-indentation))
424 (t ; File was not filled.
425 (if enriched-verbose (message "Filling paragraphs..."))
426 (fill-region (point-min) (point-max))))
427 (if enriched-verbose (message nil)))
430 (defun enriched-next-annotation ()
431 "Find and return next text/enriched annotation.
432 Any \"<<\" strings encountered are converted to \"<\".
433 Return value is \(begin end name positive-p), or nil if none was found."
434 (while (and (search-forward "<" nil 1)
435 (progn (goto-char (match-beginning 0))
436 (not (looking-at enriched-annotation-regexp))))
438 (if (= ?< (char-after (point)))
440 ;; A single < that does not start an annotation is an error,
441 ;; which we note and then ignore.
442 (message "Warning: malformed annotation in file at %s"
445 (let* ((beg (match-beginning 0))
447 (name (downcase (buffer-substring
448 (match-beginning 2) (match-end 2))))
449 (pos (not (match-beginning 1))))
450 (list beg end name pos))))
452 (defun enriched-get-file-width ()
453 "Look for file width information on this line."
455 (if (search-forward "Text-Width: " (+ (point) 1000) t)
456 (read (current-buffer)))))
458 (defun enriched-remove-header ()
459 "Remove file-format header at point."
460 (while (looking-at "^[-A-Za-z]+: .*\n")
461 (delete-region (point) (match-end 0)))
462 (if (looking-at "^\n")
465 (defun enriched-decode-foreground (from to &optional color)
467 (list from to 'face (list ':foreground color))
468 (message "Warning: no color specified for <x-color>")
471 (defun enriched-decode-background (from to &optional color)
473 (list from to 'face (list ':background color))
474 (message "Warning: no color specified for <x-bg-color>")
477 ;;; Handling the `display' property.
480 (defun enriched-handle-display-prop (old new)
481 "Return a list of annotations for a change in the `display' property.
482 OLD is the old value of the property, NEW is the new value. Value
483 is a list `(CLOSE OPEN)', where CLOSE is a list of annotations to
484 close and OPEN a list of annotations to open. Each of these lists
485 has the form `(ANNOTATION PARAM ...)'."
486 (let ((annotation "x-display")
487 (param (prin1-to-string (or old new))))
489 (cons nil (list (list annotation param)))
490 (cons (list (list annotation param)) nil))))
492 (defun enriched-decode-display-prop (start end &optional param)
493 "Decode a `display' property for text between START and END.
494 PARAM is a `<param>' found for the property.
495 Value is a list `(START END SYMBOL VALUE)' with START and END denoting
496 the range of text to assign text property SYMBOL with value VALUE."
497 (let ((prop (when (stringp param)
499 (car (read-from-string param))
502 (message "Warning: invalid <x-display> parameter %s" param))
503 (list start end 'display prop)))
505 ;;; arch-tag: 05cae488-3fea-45cd-ac29-5b02cb64e42b
506 ;;; enriched.el ends here