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[emacs.git] / lisp / mail / mail-hist.el
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1 ;;; mail-hist.el --- Headers and message body history for outgoing mail.
3 ;; Copyright (C) 1994 Free Software Foundation, Inc.
5 ;; Author: Karl Fogel <kfogel@red-bean.com>
6 ;; Created: March, 1994
7 ;; Keywords: mail, history
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; any later version.
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24 ;; Boston, MA 02111-1307, USA.
26 ;;; Commentary:
28 ;; Thanks to Jim Blandy for mentioning ring.el. It saved a lot of
29 ;; time.
31 ;; To use this package, put it in a directory in your load-path, and
32 ;; put this in your .emacs file:
34 ;; (load "mail-hist" nil t)
36 ;; Or you could do it with autoloads and hooks in your .emacs:
38 ;; (add-hook 'mail-mode-hook 'mail-hist-define-keys)
39 ;; (add-hook 'mail-send-hook 'mail-hist-put-headers-into-history)
40 ;; (add-hook 'vm-mail-mode-hook 'mail-hist-define-keys) ;or rmail, etc
41 ;; (autoload 'mail-hist-define-keys "mail-hist")
42 ;; (autoload 'mail-hist-put-headers-into-history "mail-hist")
44 ;; Once it's installed, use M-p and M-n from mail headers to recover
45 ;; previous/next contents in the history for that header, or, in the
46 ;; body of the message, to recover previous/next text of the message.
47 ;; This only applies to outgoing mail -- mail-hist ignores received
48 ;; messages.
50 ;; Although repeated history requests do clear out the text from the
51 ;; previous request, an isolated request just inserts its text at
52 ;; point, so that you can mix the histories of different messages
53 ;; easily. This might be confusing at times, but there should be no
54 ;; problems that undo can't handle.
56 ;;; Code:
57 (require 'ring)
58 (require 'sendmail)
60 (defgroup mail-hist nil
61 "Headers and message body history for outgoing mail."
62 :prefix "mail-hist-"
63 :group 'mail)
65 ;;;###autoload
66 (defun mail-hist-define-keys ()
67 "Define keys for accessing mail header history. For use in hooks."
68 (local-set-key "\M-p" 'mail-hist-previous-input)
69 (local-set-key "\M-n" 'mail-hist-next-input))
71 ;;;###autoload
72 (defun mail-hist-enable ()
73 (add-hook 'mail-mode-hook 'mail-hist-define-keys)
74 (add-hook 'mail-send-hook 'mail-hist-put-headers-into-history))
76 (defvar mail-hist-header-ring-alist nil
77 "Alist of form (header-name . history-ring).
78 Used for knowing which history list to look in when the user asks for
79 previous/next input.")
81 (defcustom mail-hist-history-size (or kill-ring-max 1729)
82 "*The maximum number of elements in a mail field's history.
83 Oldest elements are dumped first."
84 :type 'integer
85 :group 'mail-hist)
87 ;;;###autoload
88 (defcustom mail-hist-keep-history t
89 "*Non-nil means keep a history for headers and text of outgoing mail."
90 :type 'boolean
91 :group 'mail-hist)
93 ;; For handling repeated history requests
94 (defvar mail-hist-access-count 0)
96 (defvar mail-hist-last-bounds nil)
97 ;; (start . end) A pair indicating the buffer positions delimiting the
98 ;; last inserted history, so it can be replaced by a new input if the
99 ;; command is repeated.
101 (defvar mail-hist-header-regexp "^[^:]*:"
102 "Regular expression for matching headers in a mail message.")
104 (defsubst mail-hist-current-header-name ()
105 "Get name of mail header point is currently in, without the colon.
106 Returns nil if not in a header, implying that point is in the body of
107 the message."
108 (if (>= (point) (mail-text-start))
109 nil ; then we are in the body of the message
110 (save-excursion
111 (let* ((body-start
112 (mail-text-start))
113 (name-start
114 (re-search-backward mail-hist-header-regexp nil t))
115 (name-end
116 (prog2 (search-forward ":" body-start t) (1- (point)))))
117 (and
118 name-start
119 name-end
120 (downcase (buffer-substring-no-properties name-start name-end)))))))
122 (defsubst mail-hist-forward-header (count)
123 "Move forward COUNT headers (backward if COUNT is negative).
124 If last/first header is encountered first, stop there and returns
125 nil.
127 Places point on the first non-whitespace on the line following the
128 colon after the header name, or on the second space following that if
129 the header is empty."
130 (let ((boundary (mail-header-end)))
131 (and
132 (> boundary 0)
133 (let ((unstopped t))
134 (setq boundary (save-excursion
135 (goto-char boundary)
136 (beginning-of-line)
137 (1- (point))))
138 (if (> count 0)
139 (while (> count 0)
140 (setq
141 unstopped
142 (re-search-forward mail-hist-header-regexp boundary t))
143 (setq count (1- count)))
144 ;; because the current header will match too.
145 (setq count (1- count))
146 ;; count is negative
147 (while (< count 0)
148 (setq
149 unstopped
150 (re-search-backward mail-hist-header-regexp nil t))
151 (setq count (1+ count)))
152 ;; we end up behind the header, so must move to the front
153 (re-search-forward mail-hist-header-regexp boundary t))
154 ;; Now we are right after the colon
155 (and (looking-at "\\s-") (forward-char 1))
156 ;; return nil if didn't go as far as asked, otherwise point
157 unstopped))))
159 (defsubst mail-hist-beginning-of-header ()
160 "Move to the start of the current header.
161 The start of the current header is defined as one space after the
162 colon, or just after the colon if it is not followed by whitespace."
163 ;; this is slick as all heck:
164 (if (mail-hist-forward-header -1)
165 (mail-hist-forward-header 1)
166 (mail-hist-forward-header 1)
167 (mail-hist-forward-header -1)))
169 (defsubst mail-hist-current-header-contents ()
170 "Get the contents of the mail header in which point is located."
171 (save-excursion
172 (mail-hist-beginning-of-header)
173 (let ((start (point)))
174 (or (mail-hist-forward-header 1)
175 (goto-char (mail-header-end)))
176 (beginning-of-line)
177 (buffer-substring start (1- (point))))))
179 (defsubst mail-hist-get-header-ring (header)
180 "Get HEADER's history ring, or nil if none.
181 HEADER is a string without the colon."
182 (setq header (downcase header))
183 (cdr (assoc header mail-hist-header-ring-alist)))
185 (defcustom mail-hist-text-size-limit nil
186 "*Don't store any header or body with more than this many characters.
187 If the value is nil, that means no limit on text size."
188 :type '(choice (const nil) integer)
189 :group 'mail-hist)
191 (defun mail-hist-text-too-long-p (text)
192 "Return t if TEXT does not exceed mail-hist's size limit.
193 The variable `mail-hist-text-size-limit' defines this limit."
194 (if mail-hist-text-size-limit
195 (> (length text) mail-hist-text-size-limit)))
197 (defsubst mail-hist-add-header-contents-to-ring (header &optional contents)
198 "Add the contents of HEADER to the header history ring.
199 Optional argument CONTENTS is a string which will be the contents
200 \(instead of whatever's found in the header)."
201 (setq header (downcase header))
202 (let ((ctnts (or contents (mail-hist-current-header-contents)))
203 (ring (cdr (assoc header mail-hist-header-ring-alist))))
204 (if (mail-hist-text-too-long-p ctnts) (setq ctnts ""))
205 (or ring
206 ;; If the ring doesn't exist, we'll have to make it and add it
207 ;; to the mail-header-ring-alist:
208 (prog1
209 (setq ring (make-ring mail-hist-history-size))
210 (setq mail-hist-header-ring-alist
211 (cons (cons header ring) mail-hist-header-ring-alist))))
212 (ring-insert ring ctnts)))
214 ;;;###autoload
215 (defun mail-hist-put-headers-into-history ()
216 "Put headers and contents of this message into mail header history.
217 Each header has its own independent history, as does the body of the
218 message.
220 This function normally would be called when the message is sent."
221 (and
222 mail-hist-keep-history
223 (save-excursion
224 (goto-char (point-min))
225 (while (mail-hist-forward-header 1)
226 (mail-hist-add-header-contents-to-ring
227 (mail-hist-current-header-name)))
228 (let ((body-contents
229 (buffer-substring (mail-text-start) (point-max))))
230 (mail-hist-add-header-contents-to-ring "body" body-contents)))))
234 (defun mail-hist-retrieve-and-insert (header access-func)
235 "Helper for `mail-hist-previous-input' and `mail-hist-next-input'."
236 (setq header (downcase header))
237 (let* ((ring (cdr (assoc header mail-hist-header-ring-alist)))
238 (len (ring-length ring))
239 (repeat (eq last-command 'mail-hist-input-access)))
240 (if repeat
241 (setq mail-hist-access-count
242 (funcall access-func mail-hist-access-count len))
243 (setq mail-hist-access-count 0))
244 (if (null ring)
245 (progn
246 (ding)
247 (message "No history for \"%s\"." header))
248 (if (ring-empty-p ring)
249 (error "\"%s\" ring is empty." header)
250 (and repeat
251 (delete-region (car mail-hist-last-bounds)
252 (cdr mail-hist-last-bounds)))
253 (let ((start (point)))
254 (insert (ring-ref ring mail-hist-access-count))
255 (setq mail-hist-last-bounds (cons start (point)))
256 (setq this-command 'mail-hist-input-access)
257 ;; Special case: when flipping through message bodies, it's
258 ;; usually most useful for point to stay at the top. This
259 ;; is because the unique part of a message in a thread is
260 ;; more likely to be at the top than the bottom, as the
261 ;; bottom is often just the same quoted history for every
262 ;; message in the thread, differing only in indentation
263 ;; level.
264 (if (string-equal header "body")
265 (goto-char start)))
266 ))))
269 (defun mail-hist-previous-input (header)
270 "Insert the previous contents of this mail header or message body.
271 Moves back through the history of sent mail messages. Each header has
272 its own independent history, as does the body of the message.
274 The history only contains the contents of outgoing messages, not
275 received mail."
276 (interactive (list (or (mail-hist-current-header-name) "body")))
277 (mail-hist-retrieve-and-insert header 'ring-plus1))
280 (defun mail-hist-next-input (header)
281 "Insert next contents of this mail header or message body.
282 Moves back through the history of sent mail messages. Each header has
283 its own independent history, as does the body of the message.
285 Although you can do so, it does not make much sense to call this
286 without having called `mail-hist-previous-header' first
287 (\\[mail-hist-previous-header]).
289 The history only contains the contents of outgoing messages, not
290 received mail."
291 (interactive (list (or (mail-hist-current-header-name) "body")))
292 (mail-hist-retrieve-and-insert header 'ring-minus1))
295 (provide 'mail-hist)
297 ;; mail-hist.el ends here