lisp/gnus/gnus-cite.el

   1 ;;; gnus-cite.el --- parse citations in articles for Gnus
   2
   3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   4 ;;   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   5
   6 ;; Author: Per Abhiddenware
   7
   8 ;; This file is part of GNU Emacs.
   9
  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 3 of the License, or
  13 ;; (at your option) any later version.
  14
  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.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28 (eval-when-compile
  29   (when (featurep 'xemacs)
  30     (require 'easy-mmode))) ; for `define-minor-mode'
  31
  32 (require 'gnus)
  33 (require 'gnus-range)
  34 (require 'gnus-art)
  35 (require 'message)      ; for message-cite-prefix-regexp
  36
  37 ;;; Customization:
  38
  39 (defgroup gnus-cite nil
  40   "Citation."
  41   :prefix "gnus-cite-"
  42   :link '(custom-manual "(gnus)Article Highlighting")
  43   :group 'gnus-article)
  44
  45 (defcustom gnus-cited-opened-text-button-line-format "%(%{[-]%}%)\n"
  46   "Format of opened cited text buttons."
  47   :group 'gnus-cite
  48   :type 'string)
  49
  50 (defcustom gnus-cited-closed-text-button-line-format "%(%{[+]%}%)\n"
  51   "Format of closed cited text buttons."
  52   :group 'gnus-cite
  53   :type 'string)
  54
  55 (defcustom gnus-cited-lines-visible nil
  56   "The number of lines of hidden cited text to remain visible.
  57 Or a pair (cons) of numbers which are the number of lines at the top
  58 and bottom of the text, respectively, to remain visible."
  59   :group 'gnus-cite
  60   :type '(choice (const :tag "none" nil)
  61                  integer
  62                  (cons :tag "Top and Bottom" integer integer)))
  63
  64 (defcustom gnus-cite-parse-max-size 25000
  65   "Maximum article size (in bytes) where parsing citations is allowed.
  66 Set it to nil to parse all articles."
  67   :group 'gnus-cite
  68   :type '(choice (const :tag "all" nil)
  69                  integer))
  70
  71 (defcustom gnus-cite-max-prefix 20
  72   "Maximum possible length for a citation prefix."
  73   :group 'gnus-cite
  74   :type 'integer)
  75
  76 (defcustom gnus-supercite-regexp
  77   (concat "^\\(" message-cite-prefix-regexp "\\)? *"
  78           ">>>>> +\"\\([^\"\n]+\\)\" +==")
  79   "*Regexp matching normal Supercite attribution lines.
  80 The first grouping must match prefixes added by other packages."
  81   :group 'gnus-cite
  82   :type 'regexp)
  83
  84 (defcustom gnus-supercite-secondary-regexp "^.*\"\\([^\"\n]+\\)\" +=="
  85   "Regexp matching mangled Supercite attribution lines.
  86 The first regexp group should match the Supercite attribution."
  87   :group 'gnus-cite
  88   :type 'regexp)
  89
  90 (defcustom gnus-cite-minimum-match-count 2
  91   "Minimum number of identical prefixes before we believe it's a citation."
  92   :group 'gnus-cite
  93   :type 'integer)
  94
  95 ;; Some Microsoft products put in a citation that extends to the
  96 ;; remainder of the message:
  97 ;;
  98 ;;     -----Original Message-----
  99 ;;     From: ...
 100 ;;     To: ...
 101 ;;     Sent: ...   [date, in non-RFC-2822 format]
 102 ;;     Subject: ...
 103 ;;
 104 ;;     Cited message, with no prefixes
 105 ;;
 106 ;; The four headers are always the same.  But note they are prone to
 107 ;; folding without additional indentation.
 108 ;;
 109 ;; Others use "----- Original Message -----" instead, and properly quote
 110 ;; the body using "> ".  This style is handled without special cases.
 111
 112 (defcustom gnus-cite-attribution-prefix
 113   "In article\\|in <\\|On \\(Mon\\|Tue\\|Wed\\|Thu\\|Fri\\|Sat\\|Sun\\),\\|----- ?Original Message ?-----"
 114   "*Regexp matching the beginning of an attribution line."
 115   :group 'gnus-cite
 116   :type 'regexp)
 117
 118 (defcustom gnus-cite-attribution-suffix
 119   "\\(\\(wrote\\|writes\\|said\\|says\\|>\\)\\(:\\|\\.\\.\\.\\)\\|----- ?Original Message ?-----\\)[ \t]*$"
 120   "*Regexp matching the end of an attribution line.
 121 The text matching the first grouping will be used as a button."
 122   :group 'gnus-cite
 123   :type 'regexp)
 124
 125 (defcustom gnus-cite-unsightly-citation-regexp
 126   "^-----Original Message-----\nFrom: \\(.+\n\\)+\n"
 127   "Regexp matching Microsoft-type rest-of-message citations."
 128   :version "22.1"
 129   :group 'gnus-cite
 130   :type 'regexp)
 131
 132 (defcustom gnus-cite-ignore-quoted-from t
 133   "Non-nil means don't regard lines beginning with \">From \" as cited text.
 134 Those lines may have been quoted by MTAs in order not to mix up with
 135 the envelope From line."
 136   :version "22.1"
 137   :group 'gnus-cite
 138   :type 'boolean)
 139
 140 (defface gnus-cite-attribution '((t (:italic t)))
 141   "Face used for attribution lines."
 142   :group 'gnus-cite)
 143 ;; backward-compatibility alias
 144 (put 'gnus-cite-attribution-face 'face-alias 'gnus-cite-attribution)
 145 (put 'gnus-cite-attribution-face 'obsolete-face "22.1")
 146
 147 (defcustom gnus-cite-attribution-face 'gnus-cite-attribution
 148   "Face used for attribution lines.
 149 It is merged with the face for the cited text belonging to the attribution."
 150   :version "22.1"
 151   :group 'gnus-cite
 152   :type 'face)
 153
 154 (defface gnus-cite-1 '((((class color)
 155                          (background dark))
 156                         (:foreground "light blue"))
 157                        (((class color)
 158                          (background light))
 159                         (:foreground "MidnightBlue"))
 160                        (t
 161                         (:italic t)))
 162   "Citation face."
 163   :group 'gnus-cite)
 164 ;; backward-compatibility alias
 165 (put 'gnus-cite-face-1 'face-alias 'gnus-cite-1)
 166 (put 'gnus-cite-face-1 'obsolete-face "22.1")
 167
 168 (defface gnus-cite-2 '((((class color)
 169                          (background dark))
 170                         (:foreground "light cyan"))
 171                        (((class color)
 172                          (background light))
 173                         (:foreground "firebrick"))
 174                        (t
 175                         (:italic t)))
 176   "Citation face."
 177   :group 'gnus-cite)
 178 ;; backward-compatibility alias
 179 (put 'gnus-cite-face-2 'face-alias 'gnus-cite-2)
 180 (put 'gnus-cite-face-2 'obsolete-face "22.1")
 181
 182 (defface gnus-cite-3 '((((class color)
 183                          (background dark))
 184                         (:foreground "light yellow"))
 185                        (((class color)
 186                          (background light))
 187                         (:foreground "dark green"))
 188                        (t
 189                         (:italic t)))
 190   "Citation face."
 191   :group 'gnus-cite)
 192 ;; backward-compatibility alias
 193 (put 'gnus-cite-face-3 'face-alias 'gnus-cite-3)
 194 (put 'gnus-cite-face-3 'obsolete-face "22.1")
 195
 196 (defface gnus-cite-4 '((((class color)
 197                          (background dark))
 198                         (:foreground "light pink"))
 199                        (((class color)
 200                          (background light))
 201                         (:foreground "OrangeRed"))
 202                        (t
 203                         (:italic t)))
 204   "Citation face."
 205   :group 'gnus-cite)
 206 ;; backward-compatibility alias
 207 (put 'gnus-cite-face-4 'face-alias 'gnus-cite-4)
 208 (put 'gnus-cite-face-4 'obsolete-face "22.1")
 209
 210 (defface gnus-cite-5 '((((class color)
 211                          (background dark))
 212                         (:foreground "pale green"))
 213                        (((class color)
 214                          (background light))
 215                         (:foreground "dark khaki"))
 216                        (t
 217                         (:italic t)))
 218   "Citation face."
 219   :group 'gnus-cite)
 220 ;; backward-compatibility alias
 221 (put 'gnus-cite-face-5 'face-alias 'gnus-cite-5)
 222 (put 'gnus-cite-face-5 'obsolete-face "22.1")
 223
 224 (defface gnus-cite-6 '((((class color)
 225                          (background dark))
 226                         (:foreground "beige"))
 227                        (((class color)
 228                          (background light))
 229                         (:foreground "dark violet"))
 230                        (t
 231                         (:italic t)))
 232   "Citation face."
 233   :group 'gnus-cite)
 234 ;; backward-compatibility alias
 235 (put 'gnus-cite-face-6 'face-alias 'gnus-cite-6)
 236 (put 'gnus-cite-face-6 'obsolete-face "22.1")
 237
 238 (defface gnus-cite-7 '((((class color)
 239                          (background dark))
 240                         (:foreground "orange"))
 241                        (((class color)
 242                          (background light))
 243                         (:foreground "SteelBlue4"))
 244                        (t
 245                         (:italic t)))
 246   "Citation face."
 247   :group 'gnus-cite)
 248 ;; backward-compatibility alias
 249 (put 'gnus-cite-face-7 'face-alias 'gnus-cite-7)
 250 (put 'gnus-cite-face-7 'obsolete-face "22.1")
 251
 252 (defface gnus-cite-8 '((((class color)
 253                          (background dark))
 254                         (:foreground "magenta"))
 255                        (((class color)
 256                          (background light))
 257                         (:foreground "magenta"))
 258                        (t
 259                         (:italic t)))
 260   "Citation face."
 261   :group 'gnus-cite)
 262 ;; backward-compatibility alias
 263 (put 'gnus-cite-face-8 'face-alias 'gnus-cite-8)
 264 (put 'gnus-cite-face-8 'obsolete-face "22.1")
 265
 266 (defface gnus-cite-9 '((((class color)
 267                          (background dark))
 268                         (:foreground "violet"))
 269                        (((class color)
 270                          (background light))
 271                         (:foreground "violet"))
 272                        (t
 273                         (:italic t)))
 274   "Citation face."
 275   :group 'gnus-cite)
 276 ;; backward-compatibility alias
 277 (put 'gnus-cite-face-9 'face-alias 'gnus-cite-9)
 278 (put 'gnus-cite-face-9 'obsolete-face "22.1")
 279
 280 (defface gnus-cite-10 '((((class color)
 281                           (background dark))
 282                          (:foreground "plum1"))
 283                         (((class color)
 284                           (background light))
 285                          (:foreground "medium purple"))
 286                         (t
 287                          (:italic t)))
 288   "Citation face."
 289   :group 'gnus-cite)
 290 ;; backward-compatibility alias
 291 (put 'gnus-cite-face-10 'face-alias 'gnus-cite-10)
 292 (put 'gnus-cite-face-10 'obsolete-face "22.1")
 293
 294 (defface gnus-cite-11 '((((class color)
 295                           (background dark))
 296                          (:foreground "turquoise"))
 297                         (((class color)
 298                           (background light))
 299                          (:foreground "turquoise"))
 300                         (t
 301                          (:italic t)))
 302   "Citation face."
 303   :group 'gnus-cite)
 304 ;; backward-compatibility alias
 305 (put 'gnus-cite-face-11 'face-alias 'gnus-cite-11)
 306 (put 'gnus-cite-face-11 'obsolete-face "22.1")
 307
 308 (defcustom gnus-cite-face-list
 309   '(gnus-cite-1 gnus-cite-2 gnus-cite-3 gnus-cite-4 gnus-cite-5 gnus-cite-6
 310                 gnus-cite-7 gnus-cite-8 gnus-cite-9 gnus-cite-10 gnus-cite-11)
 311   "*List of faces used for highlighting citations.
 312
 313 When there are citations from multiple articles in the same message,
 314 Gnus will try to give each citation from each article its own face.
 315 This should make it easier to see who wrote what."
 316   :group 'gnus-cite
 317   :type '(repeat face)
 318   :set (lambda (symbol value)
 319          (prog1
 320              (custom-set-default symbol value)
 321            (if (boundp 'gnus-message-max-citation-depth)
 322                (setq gnus-message-max-citation-depth (length value)))
 323            (if (boundp 'gnus-message-citation-keywords)
 324                (setq gnus-message-citation-keywords
 325                      `((gnus-message-search-citation-line
 326                         ,@(let ((list nil)
 327                                 (count 1))
 328                             (dolist (face value (nreverse list))
 329                               (push (list count (list 'quote face) 'prepend t)
 330                                     list)
 331                               (setq count (1+ count)))))))))))
 332
 333 (defcustom gnus-cite-hide-percentage 50
 334   "Only hide excess citation if above this percentage of the body."
 335   :group 'gnus-cite
 336   :type 'number)
 337
 338 (defcustom gnus-cite-hide-absolute 10
 339   "Only hide excess citation if above this number of lines in the body."
 340   :group 'gnus-cite
 341   :type 'integer)
 342
 343 (defcustom gnus-cite-blank-line-after-header t
 344   "If non-nil, put a blank line between the citation header and the button."
 345   :group 'gnus-cite
 346   :type 'boolean)
 347
 348 ;; This has to go here because its default value depends on
 349 ;; gnus-cite-face-list.
 350 (defcustom gnus-article-boring-faces (cons 'gnus-signature gnus-cite-face-list)
 351   "List of faces that are not worth reading.
 352 If an article has more pages below the one you are looking at, but
 353 nothing on those pages is a word of at least three letters that is not
 354 in a boring face, then the pages will be skipped."
 355   :type '(repeat face)
 356   :group 'gnus-article-hiding)
 357
 358 ;;; Internal Variables:
 359
 360 (defvar gnus-cite-article nil)
 361 (defvar gnus-cite-overlay-list nil)
 362
 363 (defvar gnus-cite-prefix-alist nil)
 364 ;; Alist of citation prefixes.
 365 ;; The cdr is a list of lines with that prefix.
 366
 367 (defvar gnus-cite-attribution-alist nil)
 368 ;; Alist of attribution lines.
 369 ;; The car is a line number.
 370 ;; The cdr is the prefix for the citation started by that line.
 371
 372 (defvar gnus-cite-loose-prefix-alist nil)
 373 ;; Alist of citation prefixes that have no matching attribution.
 374 ;; The cdr is a list of lines with that prefix.
 375
 376 (defvar gnus-cite-loose-attribution-alist nil)
 377 ;; Alist of attribution lines that have no matching citation.
 378 ;; Each member has the form (WROTE IN PREFIX TAG), where
 379 ;; WROTE: is the attribution line number
 380 ;; IN: is the line number of the previous line if part of the same attribution,
 381 ;; PREFIX: Is the citation prefix of the attribution line(s), and
 382 ;; TAG: Is a Supercite tag, if any.
 383
 384 (defvar gnus-cited-opened-text-button-line-format-alist
 385   `((?b (marker-position beg) ?d)
 386     (?e (marker-position end) ?d)
 387     (?n (count-lines beg end) ?d)
 388     (?l (- end beg) ?d)))
 389 (defvar gnus-cited-opened-text-button-line-format-spec nil)
 390 (defvar gnus-cited-closed-text-button-line-format-alist
 391   gnus-cited-opened-text-button-line-format-alist)
 392 (defvar gnus-cited-closed-text-button-line-format-spec nil)
 393
 394
 395 ;;; Commands:
 396
 397 (defun gnus-article-highlight-citation (&optional force same-buffer)
 398   "Highlight cited text.
 399 Each citation in the article will be highlighted with a different face.
 400 The faces are taken from `gnus-cite-face-list'.
 401 Attribution lines are highlighted with the same face as the
 402 corresponding citation merged with the face `gnus-cite-attribution'.
 403
 404 Text is considered cited if at least `gnus-cite-minimum-match-count'
 405 lines matches `message-cite-prefix-regexp' with the same prefix.
 406
 407 Lines matching `gnus-cite-attribution-suffix' and perhaps
 408 `gnus-cite-attribution-prefix' are considered attribution lines."
 409   (interactive (list 'force))
 410   (with-current-buffer (if same-buffer (current-buffer) gnus-article-buffer)
 411     (gnus-cite-parse-maybe force)
 412     (let ((buffer-read-only nil)
 413           (alist gnus-cite-prefix-alist)
 414           (faces gnus-cite-face-list)
 415           (inhibit-point-motion-hooks t)
 416           face entry prefix skip numbers number face-alist)
 417       ;; Loop through citation prefixes.
 418       (while alist
 419         (setq entry (car alist)
 420               alist (cdr alist)
 421               prefix (car entry)
 422               numbers (cdr entry)
 423               face (car faces)
 424               faces (or (cdr faces) gnus-cite-face-list)
 425               face-alist (cons (cons prefix face) face-alist))
 426         (while numbers
 427           (setq number (car numbers)
 428                 numbers (cdr numbers))
 429           (and (not (assq number gnus-cite-attribution-alist))
 430                (not (assq number gnus-cite-loose-attribution-alist))
 431                (gnus-cite-add-face number prefix face))))
 432       ;; Loop through attribution lines.
 433       (setq alist gnus-cite-attribution-alist)
 434       (while alist
 435         (setq entry (car alist)
 436               alist (cdr alist)
 437               number (car entry)
 438               prefix (cdr entry)
 439               skip (gnus-cite-find-prefix number)
 440               face (cdr (assoc prefix face-alist)))
 441         ;; Add attribution button.
 442         (goto-char (point-min))
 443         (forward-line (1- number))
 444         (when (re-search-forward gnus-cite-attribution-suffix
 445                                  (point-at-eol)
 446                                  t)
 447           (gnus-article-add-button (match-beginning 1) (match-end 1)
 448                                    'gnus-cite-toggle prefix))
 449         ;; Highlight attribution line.
 450         (gnus-cite-add-face number skip face)
 451         (gnus-cite-add-face number skip gnus-cite-attribution-face))
 452       ;; Loop through attribution lines.
 453       (setq alist gnus-cite-loose-attribution-alist)
 454       (while alist
 455         (setq entry (car alist)
 456               alist (cdr alist)
 457               number (car entry)
 458               skip (gnus-cite-find-prefix number))
 459         (gnus-cite-add-face number skip gnus-cite-attribution-face)))))
 460
 461 (defun gnus-dissect-cited-text ()
 462   "Dissect the article buffer looking for cited text."
 463   (with-current-buffer gnus-article-buffer
 464     (gnus-cite-parse-maybe nil t)
 465     (let ((alist gnus-cite-prefix-alist)
 466           prefix numbers number marks m)
 467       ;; Loop through citation prefixes.
 468       (while alist
 469         (setq numbers (pop alist)
 470               prefix (pop numbers))
 471         (while numbers
 472           (setq number (pop numbers))
 473           (goto-char (point-min))
 474           (forward-line number)
 475           (push (cons (point-marker) "") marks)
 476           (while (and numbers
 477                       (= (1- number) (car numbers)))
 478             (setq number (pop numbers)))
 479           (goto-char (point-min))
 480           (forward-line (1- number))
 481           (push (cons (point-marker) prefix) marks)))
 482       ;; Skip to the beginning of the body.
 483       (article-goto-body)
 484       (push (cons (point-marker) "") marks)
 485       ;; Find the end of the body.
 486       (goto-char (point-max))
 487       (gnus-article-search-signature)
 488       (push (cons (point-marker) "") marks)
 489       ;; Sort the marks.
 490       (setq marks (sort marks 'car-less-than-car))
 491       (let ((omarks marks))
 492         (setq marks nil)
 493         (while (cdr omarks)
 494           (if (= (caar omarks) (caadr omarks))
 495               (progn
 496                 (unless (equal (cdar omarks) "")
 497                   (push (car omarks) marks))
 498                 (unless (equal (cdadr omarks) "")
 499                   (push (cadr omarks) marks))
 500                 (unless (and (equal (cdar omarks) "")
 501                              (equal (cdadr omarks) "")
 502                              (not (cddr omarks)))
 503                   (setq omarks (cdr omarks))))
 504             (push (car omarks) marks))
 505           (setq omarks (cdr omarks)))
 506         (when (car omarks)
 507           (push (car omarks) marks))
 508         (setq marks (setq m (nreverse marks)))
 509         (while (cddr m)
 510           (if (and (equal (cdadr m) "")
 511                    (equal (cdar m) (cdaddr m))
 512                    (goto-char (caadr m))
 513                    (forward-line 1)
 514                    (= (point) (caaddr m)))
 515               (setcdr m (cdddr m))
 516             (setq m (cdr m))))
 517         marks))))
 518
 519 (defun gnus-article-fill-cited-long-lines ()
 520   (gnus-article-fill-cited-article nil t))
 521
 522 (defun gnus-article-fill-cited-article (&optional width long-lines)
 523   "Do word wrapping in the current article.
 524 If WIDTH (the numerical prefix), use that text width when
 525 filling.  If LONG-LINES, only fill sections that have lines
 526 longer than the frame width."
 527   (interactive "P")
 528   (with-current-buffer gnus-article-buffer
 529     (let ((buffer-read-only nil)
 530           (inhibit-point-motion-hooks t)
 531           (marks (gnus-dissect-cited-text))
 532           (adaptive-fill-mode nil)
 533           (filladapt-mode nil)
 534           (fill-column (if width (prefix-numeric-value width) fill-column)))
 535       (save-restriction
 536         (while (cdr marks)
 537           (narrow-to-region (caar marks) (caadr marks))
 538           (let ((adaptive-fill-regexp
 539                  (concat "^" (regexp-quote (cdar marks)) " *"))
 540                 (fill-prefix
 541                  (if (string= (cdar marks) "") ""
 542                    (concat (cdar marks) " ")))
 543                 (do-fill (not long-lines))
 544                 use-hard-newlines)
 545             (unless do-fill
 546               (setq do-fill (gnus-article-foldable-buffer (cdar marks))))
 547             ;; Note: the XEmacs version of `fill-region' inserts a newline
 548             ;; unless the region ends with a newline.
 549             (when do-fill
 550               (if (not long-lines)
 551                   (fill-region (point-min) (point-max))
 552                 (goto-char (point-min))
 553                 (while (not (eobp))
 554                   (end-of-line)
 555                   (when (prog1
 556                             (> (current-column) (window-width))
 557                           (forward-line 1))
 558                     (save-restriction
 559                       (narrow-to-region (line-beginning-position 0) (point))
 560                       (fill-region (point-min) (point-max))))))))
 561           (set-marker (caar marks) nil)
 562           (setq marks (cdr marks)))
 563         (when marks
 564           (set-marker (caar marks) nil))
 565         ;; All this information is now incorrect.
 566         (setq gnus-cite-prefix-alist nil
 567               gnus-cite-attribution-alist nil
 568               gnus-cite-loose-prefix-alist nil
 569               gnus-cite-loose-attribution-alist nil
 570               gnus-cite-article nil)))))
 571
 572 (defun gnus-article-foldable-buffer (prefix)
 573   (let ((do-fill nil)
 574         columns)
 575     (goto-char (point-min))
 576     (while (not (eobp))
 577       (unless (> (length prefix) (- (point-max) (point)))
 578         (forward-char (length prefix)))
 579       (skip-chars-forward " \t")
 580       (unless (eolp)
 581         (let ((elem (assq (current-column) columns)))
 582           (unless elem
 583             (setq elem (cons (current-column) 0))
 584             (push elem columns))
 585           (setcdr elem (1+ (cdr elem)))))
 586       (end-of-line)
 587       (when (> (current-column) (window-width))
 588         (setq do-fill t))
 589       (forward-line 1))
 590     (and do-fill
 591          ;; We know know that there are long lines here, but does this look
 592          ;; like code?  Check for ragged edges on the left.
 593          (< (length columns) 3))))
 594
 595 (defun gnus-article-natural-long-line-p ()
 596   "Return true if the current line is long, and it's natural text."
 597   (save-excursion
 598     (beginning-of-line)
 599     (and
 600      ;; The line is long.
 601      (> (- (line-end-position) (line-beginning-position))
 602         (window-width))
 603      ;; It doesn't start with spaces.
 604      (not (looking-at "    "))
 605      ;; Not cited text.
 606      (let ((line-number (1+ (count-lines (point-min) (point))))
 607            citep)
 608        (dolist (elem gnus-cite-prefix-alist)
 609          (when (member line-number (cdr elem))
 610            (setq citep t)))
 611        (not citep)))))
 612
 613 (defun gnus-article-hide-citation (&optional arg force)
 614   "Toggle hiding of all cited text except attribution lines.
 615 See the documentation for `gnus-article-highlight-citation'.
 616 If given a negative prefix, always show; if given a positive prefix,
 617 always hide."
 618   (interactive (append (gnus-article-hidden-arg) (list 'force)))
 619   (gnus-set-format 'cited-opened-text-button t)
 620   (gnus-set-format 'cited-closed-text-button t)
 621   (with-current-buffer gnus-article-buffer
 622     (let ((buffer-read-only nil)
 623           marks
 624           (inhibit-point-motion-hooks t)
 625           (props (nconc (list 'article-type 'cite)
 626                         gnus-hidden-properties))
 627           (point (point-min))
 628           found beg end start)
 629       (while (setq point
 630                    (text-property-any point (point-max)
 631                                       'gnus-callback
 632                                       'gnus-article-toggle-cited-text))
 633         (setq found t)
 634         (goto-char point)
 635         (gnus-article-toggle-cited-text
 636          (get-text-property point 'gnus-data) arg)
 637         (forward-line 1)
 638         (setq point (point)))
 639       (unless found
 640         (setq marks (gnus-dissect-cited-text))
 641         (while marks
 642           (setq beg nil
 643                 end nil)
 644           (while (and marks (string= (cdar marks) ""))
 645             (setq marks (cdr marks)))
 646           (when marks
 647             (setq beg (caar marks)))
 648           (while (and marks (not (string= (cdar marks) "")))
 649             (setq marks (cdr marks)))
 650           (when marks
 651             (setq end (caar marks)))
 652           ;; Skip past lines we want to leave visible.
 653           (when (and beg end gnus-cited-lines-visible)
 654             (goto-char beg)
 655             (forward-line (if (consp gnus-cited-lines-visible)
 656                               (car gnus-cited-lines-visible)
 657                             gnus-cited-lines-visible))
 658             (if (>= (point) end)
 659                 (setq beg nil)
 660               (setq beg (point-marker))
 661               (when (consp gnus-cited-lines-visible)
 662                 (goto-char end)
 663                 (forward-line (- (cdr gnus-cited-lines-visible)))
 664                 (if (<= (point) beg)
 665                     (setq beg nil)
 666                   (setq end (point-marker))))))
 667           (when (and beg end)
 668             (gnus-add-wash-type 'cite)
 669             ;; We use markers for the end-points to facilitate later
 670             ;; wrapping and mangling of text.
 671             (setq beg (set-marker (make-marker) beg)
 672                   end (set-marker (make-marker) end))
 673             (gnus-add-text-properties-when 'article-type nil beg end props)
 674             (goto-char beg)
 675             (when (and gnus-cite-blank-line-after-header
 676                        (not (save-excursion (search-backward "\n\n" nil t))))
 677               (insert "\n"))
 678             (put-text-property
 679              (setq start (point-marker))
 680              (progn
 681                (gnus-article-add-button
 682                 (point)
 683                 (progn (eval gnus-cited-closed-text-button-line-format-spec)
 684                        (point))
 685                 `gnus-article-toggle-cited-text
 686                 (list (cons beg end) start))
 687                (point))
 688              'article-type 'annotation)
 689             (set-marker beg (point))))))))
 690
 691 (defun gnus-article-toggle-cited-text (args &optional arg)
 692   "Toggle hiding the text in REGION.
 693 ARG can be nil or a number.  Positive means hide, negative
 694 means show, nil means toggle."
 695   (let* ((region (car args))
 696          (beg (car region))
 697          (end (cdr region))
 698          (start (cadr args))
 699          (hidden
 700           (text-property-any beg (1- end) 'article-type 'cite))
 701          (inhibit-point-motion-hooks t)
 702          buffer-read-only)
 703     (when (or (null arg)
 704               (zerop arg)
 705               (and (> arg 0) (not hidden))
 706               (and (< arg 0) hidden))
 707       (if hidden
 708           (progn
 709             ;; Can't remove 'cite from g-a-wash-types here because
 710             ;; multiple citations may be hidden -jas
 711             (gnus-remove-text-properties-when
 712              'article-type 'cite beg end
 713              (cons 'article-type (cons 'cite
 714                                        gnus-hidden-properties))))
 715         (gnus-add-wash-type 'cite)
 716         (gnus-add-text-properties-when
 717          'article-type nil beg end
 718          (cons 'article-type (cons 'cite
 719                                    gnus-hidden-properties))))
 720       (let ((gnus-article-mime-handle-alist-1 gnus-article-mime-handle-alist))
 721         (gnus-set-mode-line 'article))
 722       (save-excursion
 723         (goto-char start)
 724         (gnus-delete-line)
 725         (put-text-property
 726          (point)
 727          (progn
 728            (gnus-article-add-button
 729             (point)
 730             (progn (eval
 731                     (if hidden
 732                         gnus-cited-opened-text-button-line-format-spec
 733                       gnus-cited-closed-text-button-line-format-spec))
 734                    (point))
 735             `gnus-article-toggle-cited-text
 736             args)
 737            (point))
 738          'article-type 'annotation)))))
 739
 740 (defun gnus-article-hide-citation-maybe (&optional arg force)
 741   "Toggle hiding of cited text that has an attribution line.
 742 If given a negative prefix, always show; if given a positive prefix,
 743 always hide.
 744 This will do nothing unless at least `gnus-cite-hide-percentage'
 745 percent and at least `gnus-cite-hide-absolute' lines of the body is
 746 cited text with attributions.  When called interactively, these two
 747 variables are ignored.
 748 See also the documentation for `gnus-article-highlight-citation'."
 749   (interactive (append (gnus-article-hidden-arg) '(force)))
 750   (with-current-buffer gnus-article-buffer
 751     (gnus-delete-wash-type 'cite)
 752     (unless (gnus-article-check-hidden-text 'cite arg)
 753       (save-excursion
 754         (gnus-cite-parse-maybe force)
 755         (article-goto-body)
 756         (let ((start (point))
 757               (atts gnus-cite-attribution-alist)
 758               (buffer-read-only nil)
 759               (inhibit-point-motion-hooks t)
 760               (hidden 0)
 761               total)
 762           (goto-char (point-max))
 763           (gnus-article-search-signature)
 764           (setq total (count-lines start (point)))
 765           (while atts
 766             (setq hidden (+ hidden (length (cdr (assoc (cdar atts)
 767                                                        gnus-cite-prefix-alist))))
 768                   atts (cdr atts)))
 769           (when (or force
 770                     (and (> (* 100 hidden) (* gnus-cite-hide-percentage total))
 771                          (> hidden gnus-cite-hide-absolute)))
 772             (gnus-add-wash-type 'cite)
 773             (setq atts gnus-cite-attribution-alist)
 774             (while atts
 775               (setq total (cdr (assoc (cdar atts) gnus-cite-prefix-alist))
 776                     atts (cdr atts))
 777               (while total
 778                 (setq hidden (car total)
 779                       total (cdr total))
 780                 (goto-char (point-min))
 781                 (forward-line (1- hidden))
 782                 (unless (assq hidden gnus-cite-attribution-alist)
 783                   (gnus-add-text-properties
 784                    (point) (progn (forward-line 1) (point))
 785                    (nconc (list 'article-type 'cite)
 786                           gnus-hidden-properties)))))))))
 787     (gnus-set-mode-line 'article)))
 788
 789 (defun gnus-article-hide-citation-in-followups ()
 790   "Hide cited text in non-root articles."
 791   (interactive)
 792   (with-current-buffer gnus-article-buffer
 793     (let ((article (cdr gnus-article-current)))
 794       (unless (with-current-buffer gnus-summary-buffer
 795                 (gnus-article-displayed-root-p article))
 796         (gnus-article-hide-citation)))))
 797
 798 ;;; Internal functions:
 799
 800 (defun gnus-cite-parse-maybe (&optional force no-overlay)
 801   "Always parse the buffer."
 802   (gnus-cite-localize)
 803   ;;Reset parser information.
 804   (setq gnus-cite-prefix-alist nil
 805         gnus-cite-attribution-alist nil
 806         gnus-cite-loose-prefix-alist nil
 807         gnus-cite-loose-attribution-alist nil)
 808   (unless no-overlay
 809     (gnus-cite-delete-overlays))
 810   ;; Parse if not too large.
 811   (if (and gnus-cite-parse-max-size
 812            (> (buffer-size) gnus-cite-parse-max-size))
 813       ()
 814     (setq gnus-cite-article (cons (car gnus-article-current)
 815                                   (cdr gnus-article-current)))
 816     (gnus-cite-parse-wrapper)))
 817
 818 (defun gnus-cite-delete-overlays ()
 819   (dolist (overlay gnus-cite-overlay-list)
 820     (ignore-errors
 821       (when (or (not (gnus-overlay-end overlay))
 822                 (and (>= (gnus-overlay-end overlay) (point-min))
 823                      (<= (gnus-overlay-end overlay) (point-max))))
 824         (setq gnus-cite-overlay-list (delete overlay gnus-cite-overlay-list))
 825         (ignore-errors
 826           (gnus-delete-overlay overlay))))))
 827
 828 (defun gnus-cite-parse-wrapper ()
 829   ;; Wrap chopped gnus-cite-parse.
 830   (article-goto-body)
 831   (let ((inhibit-point-motion-hooks t))
 832     (save-excursion
 833       (gnus-cite-parse-attributions))
 834     (save-excursion
 835       (gnus-cite-parse))
 836     (save-excursion
 837       (gnus-cite-connect-attributions))))
 838
 839 (defun gnus-cite-parse ()
 840   ;; Parse and connect citation prefixes and attribution lines.
 841
 842   ;; Parse current buffer searching for citation prefixes.
 843   (let ((line (1+ (count-lines (point-min) (point))))
 844         (case-fold-search t)
 845         (max (save-excursion
 846                (goto-char (point-max))
 847                (gnus-article-search-signature)
 848                (point)))
 849         (prefix-regexp (concat "^\\(" message-cite-prefix-regexp "\\)"))
 850         alist entry start begin end numbers prefix guess-limit)
 851     ;; Get all potential prefixes in `alist'.
 852     (while (< (point) max)
 853       ;; Each line.
 854       (setq begin (point)
 855             guess-limit (progn (skip-chars-forward "^> \t\r\n") (point))
 856             end (point-at-bol 2)
 857             start end)
 858       (goto-char begin)
 859       ;; Ignore standard Supercite attribution prefix.
 860       (when (and (< guess-limit (+ begin gnus-cite-max-prefix))
 861                  (looking-at gnus-supercite-regexp))
 862         (if (match-end 1)
 863             (setq end (1+ (match-end 1)))
 864           (setq end (1+ begin))))
 865       ;; Ignore very long prefixes.
 866       (when (> end (+ begin gnus-cite-max-prefix))
 867         (setq end (+ begin gnus-cite-max-prefix)))
 868       ;; Ignore quoted envelope From_.
 869       (when (and gnus-cite-ignore-quoted-from
 870                  (prog2
 871                      (setq case-fold-search nil)
 872                      (looking-at ">From ")
 873                    (setq case-fold-search t)))
 874         (setq end (1+ begin)))
 875       (while (re-search-forward prefix-regexp (1- end) t)
 876         ;; Each prefix.
 877         (setq end (match-end 0)
 878               prefix (buffer-substring begin end))
 879         (set-text-properties 0 (length prefix) nil prefix)
 880         (setq entry (assoc prefix alist))
 881         (if entry
 882             (setcdr entry (cons line (cdr entry)))
 883           (push (list prefix line) alist))
 884         (goto-char begin))
 885       (goto-char start)
 886       (setq line (1+ line)))
 887     ;; Horrible special case for some Microsoft mailers.
 888     (goto-char (point-min))
 889     (setq start t begin nil entry nil)
 890     (while start
 891       ;; Assume this search ends up at the beginning of a line.
 892       (if (re-search-forward gnus-cite-unsightly-citation-regexp max t)
 893           (progn
 894             (when (number-or-marker-p start)
 895               (setq begin (count-lines (point-min) start)
 896                     end (count-lines (point-min) (match-beginning 0))))
 897             (setq start (match-end 0)))
 898         (when (number-or-marker-p start)
 899           (setq begin (count-lines (point-min) start)
 900                 end (count-lines (point-min) max)))
 901         (setq start nil))
 902       (when begin
 903         (while (< begin end)
 904           ;; Need to do 1+ because we're in the bol.
 905           (push (setq begin (1+ begin)) entry))))
 906     (when entry
 907       (push (cons "" entry) alist))
 908     ;; We got all the potential prefixes.  Now create
 909     ;; `gnus-cite-prefix-alist' containing the oldest prefix for each
 910     ;; line that appears at least `gnus-cite-minimum-match-count'
 911     ;; times.  First sort them by length.  Longer is older.
 912     (setq alist (sort alist (lambda (a b)
 913                               (> (length (car a)) (length (car b))))))
 914     (while alist
 915       (setq entry (car alist)
 916             prefix (car entry)
 917             numbers (cdr entry)
 918             alist (cdr alist))
 919       (cond ((null numbers)
 920              ;; No lines with this prefix that wasn't also part of
 921              ;; a longer prefix.
 922              )
 923             ((< (length numbers) gnus-cite-minimum-match-count)
 924              ;; Too few lines with this prefix.  We keep it a bit
 925              ;; longer in case it is an exact match for an attribution
 926              ;; line, but we don't remove the line from other
 927              ;; prefixes.
 928              (push entry gnus-cite-prefix-alist))
 929             (t
 930              (push entry
 931                    gnus-cite-prefix-alist)
 932              ;; Remove articles from other prefixes.
 933              (let ((loop alist)
 934                    current)
 935                (while loop
 936                  (setq current (car loop)
 937                        loop (cdr loop))
 938                  (setcdr current
 939                          (gnus-set-difference (cdr current) numbers)))))))))
 940
 941 (defun gnus-cite-parse-attributions ()
 942   (let (al-alist)
 943     ;; Parse attributions
 944     (while (re-search-forward gnus-cite-attribution-suffix (point-max) t)
 945       (let* ((start (match-beginning 0))
 946              (end (match-end 0))
 947              (wrote (count-lines (point-min) end))
 948              (prefix (gnus-cite-find-prefix wrote))
 949              ;; Check previous line for an attribution leader.
 950              (tag (progn
 951                     (beginning-of-line 1)
 952                     (when (looking-at gnus-supercite-secondary-regexp)
 953                       (buffer-substring (match-beginning 1)
 954                                         (match-end 1)))))
 955              (in (progn
 956                    (goto-char start)
 957                    (and (re-search-backward gnus-cite-attribution-prefix
 958                                             (save-excursion
 959                                               (beginning-of-line 0)
 960                                               (point))
 961                                             t)
 962                         (not (re-search-forward gnus-cite-attribution-suffix
 963                                                 start t))
 964                         (count-lines (point-min) (1+ (point)))))))
 965         (when (eq wrote in)
 966           (setq in nil))
 967         (goto-char end)
 968         ;; don't add duplicates
 969         (let ((al (buffer-substring (save-excursion (beginning-of-line 0)
 970                                                     (1+ (point)))
 971                                     end)))
 972           (when (not (assoc al al-alist))
 973             (push (list wrote in prefix tag)
 974                   gnus-cite-loose-attribution-alist)
 975             (push (cons al t) al-alist)))))))
 976
 977 (defun gnus-cite-connect-attributions ()
 978   ;; Connect attributions to citations
 979
 980   ;; No citations have been connected to attribution lines yet.
 981   (setq gnus-cite-loose-prefix-alist (append gnus-cite-prefix-alist nil))
 982
 983   ;; Parse current buffer searching for attribution lines.
 984   ;; Find exact supercite citations.
 985   (gnus-cite-match-attributions 'small nil
 986                                 (lambda (prefix tag)
 987                                   (when tag
 988                                     (concat "\\`"
 989                                             (regexp-quote prefix) "[ \t]*"
 990                                             (regexp-quote tag) ">"))))
 991   ;; Find loose supercite citations after attributions.
 992   (gnus-cite-match-attributions 'small t
 993                                 (lambda (prefix tag)
 994                                   (when tag
 995                                     (concat "\\<"
 996                                             (regexp-quote tag)
 997                                             "\\>"))))
 998   ;; Find loose supercite citations anywhere.
 999   (gnus-cite-match-attributions 'small nil
1000                                 (lambda (prefix tag)
1001                                   (when tag
1002                                     (concat "\\<"
1003                                             (regexp-quote tag)
1004                                             "\\>"))))
1005   ;; Find nested citations after attributions.
1006   (gnus-cite-match-attributions 'small-if-unique t
1007                                 (lambda (prefix tag)
1008                                   (concat "\\`" (regexp-quote prefix) ".+")))
1009   ;; Find nested citations anywhere.
1010   (gnus-cite-match-attributions 'small nil
1011                                 (lambda (prefix tag)
1012                                   (concat "\\`" (regexp-quote prefix) ".+")))
1013   ;; Remove loose prefixes with too few lines.
1014   (let ((alist gnus-cite-loose-prefix-alist)
1015         entry)
1016     (while alist
1017       (setq entry (car alist)
1018             alist (cdr alist))
1019       (when (< (length (cdr entry)) gnus-cite-minimum-match-count)
1020         (setq gnus-cite-prefix-alist
1021               (delq entry gnus-cite-prefix-alist)
1022               gnus-cite-loose-prefix-alist
1023               (delq entry gnus-cite-loose-prefix-alist)))))
1024   ;; Find flat attributions.
1025   (gnus-cite-match-attributions 'first t nil)
1026   ;; Find any attributions (are we getting desperate yet?).
1027   (gnus-cite-match-attributions 'first nil nil))
1028
1029 (defun gnus-cite-match-attributions (sort after fun)
1030   ;; Match all loose attributions and citations (SORT AFTER FUN) .
1031   ;;
1032   ;; If SORT is `small', the citation with the shortest prefix will be
1033   ;; used, if it is `first' the first prefix will be used, if it is
1034   ;; `small-if-unique' the shortest prefix will be used if the
1035   ;; attribution line does not share its own prefix with other
1036   ;; loose attribution lines, otherwise the first prefix will be used.
1037   ;;
1038   ;; If AFTER is non-nil, only citations after the attribution line
1039   ;; will be considered.
1040   ;;
1041   ;; If FUN is non-nil, it will be called with the arguments (WROTE
1042   ;; PREFIX TAG) and expected to return a regular expression.  Only
1043   ;; citations whose prefix matches the regular expression will be
1044   ;; considered.
1045   ;;
1046   ;; WROTE is the attribution line number.
1047   ;; PREFIX is the attribution line prefix.
1048   ;; TAG is the Supercite tag on the attribution line.
1049   (let ((atts gnus-cite-loose-attribution-alist)
1050         (case-fold-search t)
1051         att wrote in prefix tag regexp limit smallest best size)
1052     (while atts
1053       (setq att (car atts)
1054             atts (cdr atts)
1055             wrote (nth 0 att)
1056             in (nth 1 att)
1057             prefix (nth 2 att)
1058             tag (nth 3 att)
1059             regexp (if fun (funcall fun prefix tag) "")
1060             size (cond ((eq sort 'small) t)
1061                        ((eq sort 'first) nil)
1062                        (t (< (length (gnus-cite-find-loose prefix)) 2)))
1063             limit (if after wrote -1)
1064             smallest 1000000
1065             best nil)
1066       (let ((cites gnus-cite-loose-prefix-alist)
1067             cite candidate numbers first compare)
1068         (while cites
1069           (setq cite (car cites)
1070                 cites (cdr cites)
1071                 candidate (car cite)
1072                 numbers (cdr cite)
1073                 first (apply 'min numbers)
1074                 compare (if size (length candidate) first))
1075           (and (> first limit)
1076                regexp
1077                (string-match regexp candidate)
1078                (< compare smallest)
1079                (setq best cite
1080                      smallest compare))))
1081       (if (null best)
1082           ()
1083         (setq gnus-cite-loose-attribution-alist
1084               (delq att gnus-cite-loose-attribution-alist))
1085         (push (cons wrote (car best)) gnus-cite-attribution-alist)
1086         (when in
1087           (push (cons in (car best)) gnus-cite-attribution-alist))
1088         (when (memq best gnus-cite-loose-prefix-alist)
1089           (let ((loop gnus-cite-prefix-alist)
1090                 (numbers (cdr best))
1091                 current)
1092             (setq gnus-cite-loose-prefix-alist
1093                   (delq best gnus-cite-loose-prefix-alist))
1094             (while loop
1095               (setq current (car loop)
1096                     loop (cdr loop))
1097               (if (eq current best)
1098                   ()
1099                 (setcdr current (gnus-set-difference (cdr current) numbers))
1100                 (when (null (cdr current))
1101                   (setq gnus-cite-loose-prefix-alist
1102                         (delq current gnus-cite-loose-prefix-alist)
1103                         atts (delq current atts)))))))))))
1104
1105 (defun gnus-cite-find-loose (prefix)
1106   ;; Return a list of loose attribution lines prefixed by PREFIX.
1107   (let* ((atts gnus-cite-loose-attribution-alist)
1108          att line lines)
1109     (while atts
1110       (setq att (car atts)
1111             line (car att)
1112             atts (cdr atts))
1113       (when (string-equal (gnus-cite-find-prefix line) prefix)
1114         (push line lines)))
1115     lines))
1116
1117 (defun gnus-cite-add-face (number prefix face)
1118   ;; At line NUMBER, ignore PREFIX and add FACE to the rest of the line.
1119   (when face
1120     (let ((inhibit-point-motion-hooks t)
1121           from to overlay)
1122       (goto-char (point-min))
1123       (when (zerop (forward-line (1- number)))
1124         (forward-char (length prefix))
1125         (skip-chars-forward " \t")
1126         (setq from (point))
1127         (end-of-line 1)
1128         (skip-chars-backward " \t")
1129         (setq to (point))
1130         (when (< from to)
1131           (push (setq overlay (gnus-make-overlay from to))
1132                 gnus-cite-overlay-list)
1133           (gnus-overlay-put overlay 'evaporate t)
1134           (gnus-overlay-put overlay 'face face))))))
1135
1136 (defun gnus-cite-toggle (prefix)
1137   (with-current-buffer gnus-article-buffer
1138     (gnus-cite-parse-maybe nil t)
1139     (let ((buffer-read-only nil)
1140           (numbers (cdr (assoc prefix gnus-cite-prefix-alist)))
1141           (inhibit-point-motion-hooks t)
1142           number)
1143       (while numbers
1144         (setq number (car numbers)
1145               numbers (cdr numbers))
1146         (goto-char (point-min))
1147         (forward-line (1- number))
1148         (cond ((get-text-property (point) 'invisible)
1149                ;; Can't remove 'cite from g-a-wash-types here because
1150                ;; multiple citations may be hidden -jas
1151                (remove-text-properties (point) (progn (forward-line 1) (point))
1152                                        gnus-hidden-properties))
1153               ((assq number gnus-cite-attribution-alist))
1154               (t
1155                (gnus-add-wash-type 'cite)
1156                (gnus-add-text-properties
1157                 (point) (progn (forward-line 1) (point))
1158                 (nconc (list 'article-type 'cite)
1159                        gnus-hidden-properties))))
1160         (let ((gnus-article-mime-handle-alist-1
1161                gnus-article-mime-handle-alist))
1162           (gnus-set-mode-line 'article))))))
1163
1164 (defun gnus-cite-find-prefix (line)
1165   ;; Return citation prefix for LINE.
1166   (let ((alist gnus-cite-prefix-alist)
1167         (prefix "")
1168         entry)
1169     (while alist
1170       (setq entry (car alist)
1171             alist (cdr alist))
1172       (when (memq line (cdr entry))
1173         (setq prefix (car entry))))
1174     prefix))
1175
1176 (defun gnus-cite-localize ()
1177   "Make the citation variables local to the article buffer."
1178   (let ((vars '(gnus-cite-article
1179                 gnus-cite-overlay-list gnus-cite-prefix-alist
1180                 gnus-cite-attribution-alist gnus-cite-loose-prefix-alist
1181                 gnus-cite-loose-attribution-alist)))
1182     (while vars
1183       (make-local-variable (pop vars)))))
1184
1185 (defun gnus-cited-line-p ()
1186   "Say whether the current line is a cited line."
1187   (save-excursion
1188     (beginning-of-line)
1189     (let ((found nil))
1190       (dolist (prefix (mapcar 'car gnus-cite-prefix-alist))
1191         (when (string= (buffer-substring (point) (+ (length prefix) (point)))
1192                        prefix)
1193           (setq found t)))
1194       found)))
1195
1196
1197 ;; Highlighting of different citation levels in message-mode.
1198 ;; - message-cite-prefix will be overridden if this is enabled.
1199
1200 (defvar gnus-message-max-citation-depth
1201   (length gnus-cite-face-list)
1202   "Maximum supported level of citation.")
1203
1204 (defvar gnus-message-cite-prefix-regexp
1205   (concat "^\\(?:" message-cite-prefix-regexp "\\)"))
1206
1207 (defun gnus-message-search-citation-line (limit)
1208   "Search for a cited line and set match data accordingly.
1209 Returns nil if there is no such line before LIMIT, t otherwise."
1210   (when (re-search-forward gnus-message-cite-prefix-regexp limit t)
1211     (let ((cdepth (min (length (apply 'concat
1212                                       (split-string
1213                                        (match-string-no-properties 0)
1214                                        "[ \t [:alnum:]]+")))
1215                        gnus-message-max-citation-depth))
1216           (mlist (make-list (* (1+ gnus-message-max-citation-depth) 2) nil))
1217           (start (point-at-bol))
1218           (end (point-at-eol)))
1219       (setcar mlist start)
1220       (setcar (cdr mlist) end)
1221       (setcar (nthcdr (* cdepth 2) mlist) start)
1222       (setcar (nthcdr (1+ (* cdepth 2)) mlist) end)
1223       (set-match-data mlist))
1224     t))
1225
1226 (defvar gnus-message-citation-keywords
1227   ;; eval-when-compile ;; This breaks in XEmacs
1228   `((gnus-message-search-citation-line
1229      ,@(let ((list nil)
1230              (count 1))
1231          ;; (require 'gnus-cite)
1232          (dolist (face gnus-cite-face-list (nreverse list))
1233            (push (list count (list 'quote face) 'prepend t) list)
1234            (setq count (1+ count)))))) ;;
1235   "Keywords for highlighting different levels of message citations.")
1236
1237 (defvar font-lock-defaults-computed)
1238 (defvar font-lock-keywords)
1239 (defvar font-lock-set-defaults)
1240
1241 (eval-and-compile
1242   (unless (featurep 'xemacs)
1243     (autoload 'font-lock-set-defaults "font-lock")))
1244
1245 (define-minor-mode gnus-message-citation-mode
1246   "Toggle `gnus-message-citation-mode' in current buffer.
1247 This buffer local minor mode provides additional font-lock support for
1248 nested citations.
1249 With prefix ARG, turn `gnus-message-citation-mode' on if and only if ARG
1250 is positive.
1251 Automatically turn `font-lock-mode' on when `gnus-message-citation-mode'
1252 is turned on."
1253   nil ;; init-value
1254   "" ;; lighter
1255   nil ;; keymap
1256   (when (eq major-mode 'message-mode)
1257     (let ((defaults (car (if (featurep 'xemacs)
1258                              (get 'message-mode 'font-lock-defaults)
1259                            font-lock-defaults)))
1260           default keywords)
1261       (while defaults
1262         (setq default (if (consp defaults)
1263                           (pop defaults)
1264                         (prog1
1265                             defaults
1266                           (setq defaults nil))))
1267         (if gnus-message-citation-mode
1268             ;; `gnus-message-citation-keywords' should be the last
1269             ;; elements of the keywords because the others are unlikely
1270             ;; to have the OVERRIDE flags -- XEmacs applies a keyword
1271             ;; having no OVERRIDE flag to matched text even if it has
1272             ;; already other faces, while Emacs doesn't.
1273             (set (make-local-variable default)
1274                  (append (default-value default)
1275                          gnus-message-citation-keywords))
1276           (kill-local-variable default))))
1277     ;; Force `font-lock-set-defaults' to update `font-lock-keywords'.
1278     (if (featurep 'xemacs)
1279         (progn
1280           (require 'font-lock)
1281           (setq font-lock-defaults-computed nil
1282                 font-lock-keywords nil))
1283       (setq font-lock-set-defaults nil))
1284     (font-lock-set-defaults)
1285     (cond ((symbol-value 'font-lock-mode)
1286            (font-lock-fontify-buffer))
1287           (gnus-message-citation-mode
1288            (font-lock-mode 1)))))
1289
1290 (defun turn-on-gnus-message-citation-mode ()
1291   "Turn on `gnus-message-citation-mode'."
1292   (gnus-message-citation-mode 1))
1293 (defun turn-off-gnus-message-citation-mode ()
1294   "Turn off `gnus-message-citation-mode'."
1295   (gnus-message-citation-mode -1))
1296
1297 (gnus-ems-redefine)
1298
1299 (provide 'gnus-cite)
1300
1301 ;; Local Variables:
1302 ;; coding: iso-8859-1
1303 ;; End:
1304
1305 ;;; gnus-cite.el ends here