lisp/view.el

   1 ;;; view.el --- peruse file or buffer without editing
   2
   3 ;; Copyright (C) 1985, 1989, 1994, 1995, 1997, 2000, 2001, 2002,
   4 ;;   2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Author: K. Shane Hartman
   7 ;; Maintainer: Inge Frick <inge@nada.kth.se>
   8 ;; Keywords: files
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; This package provides the `view' minor mode documented in the Emacs
  30 ;; user's manual.
  31 ;; View mode entry and exit is done through the functions view-mode-enter
  32 ;; and view-mode-exit.  Use these functions to enter or exit view-mode from
  33 ;; emacs lisp programs.
  34 ;; We use both view- and View- as prefix for symbols.  View- is used as
  35 ;; prefix for commands that have a key binding.  view- is used for commands
  36 ;; without key binding.  The purpose of this is to make it easier for a
  37 ;; user to use command name completion.
  38
  39 ;;; Suggested key bindings:
  40 ;;
  41 ;; (define-key ctl-x-4-map "v" 'view-file-other-window)  ; ^x4v
  42 ;; (define-key ctl-x-5-map "v" 'view-file-other-frame)  ; ^x5v
  43 ;;
  44 ;; You could also bind view-file, view-buffer, view-buffer-other-window and
  45 ;; view-buffer-other-frame to keys.
  46 \f
  47 ;;; Code:
  48
  49 (defgroup view nil
  50   "Peruse file or buffer without editing."
  51   :link '(function-link view-mode)
  52   :link '(custom-manual "(emacs)Misc File Ops")
  53   :group 'wp
  54   :group 'editing)
  55
  56 (defcustom view-highlight-face 'highlight
  57    "*The face used for highlighting the match found by View mode search."
  58    :type 'face
  59    :group 'view)
  60
  61 ;; `view-mode-auto-exit' is replaced by the following option variable which
  62 ;; only says if scrolling past buffer end should leave view mode or not, it
  63 ;; doesn't say if leaving view mode should restore windows or not.  The latter
  64 ;; is now controlled by the presence of a value in `view-return-to-alist'.
  65 (defcustom view-scroll-auto-exit nil
  66   "*Non-nil means scrolling past the end of buffer exits View mode.
  67 A value of nil means attempting to scroll past the end of the buffer,
  68 only rings the bell and gives a message on how to leave."
  69   :type 'boolean
  70   :group 'view)
  71
  72 (defcustom view-try-extend-at-buffer-end nil
  73  "*Non-nil means try to load more of file when reaching end of buffer.
  74 This variable is mainly intended to be temporarily set to non-nil by
  75 the F command in view-mode, but you can set it to t if you want the action
  76 for all scroll commands in view mode."
  77   :type 'boolean
  78   :group 'view)
  79
  80 ;;;###autoload
  81 (defcustom view-remove-frame-by-deleting t
  82   "*Determine how View mode removes a frame no longer needed.
  83 If nil, make an icon of the frame.  If non-nil, delete the frame."
  84   :type 'boolean
  85   :group 'view
  86   ;; Changed the default of this to t for Emacs 23.  Users consider
  87   ;; frame iconification annoying.
  88   :version "23.1")
  89
  90 (defcustom view-exits-all-viewing-windows nil
  91   "*Non-nil means restore all windows used to view buffer.
  92 Commands that restore windows when finished viewing a buffer, apply to all
  93 windows that display the buffer and have restore information in
  94 `view-return-to-alist'.
  95 If `view-exits-all-viewing-windows' is nil, only the selected window is
  96 considered for restoring."
  97   :type 'boolean
  98   :group 'view)
  99
 100 (defcustom view-inhibit-help-message nil
 101   "*Non-nil inhibits the help message shown upon entering View mode."
 102   :type 'boolean
 103   :group 'view
 104   :version "22.1")
 105
 106 ;;;###autoload
 107 (defvar view-mode nil
 108   "Non-nil if View mode is enabled.
 109 Don't change this variable directly, you must change it by one of the
 110 functions that enable or disable view mode.")
 111 ;;;###autoload
 112 (make-variable-buffer-local 'view-mode)
 113
 114 (defcustom view-mode-hook nil
 115   "Normal hook run when starting to view a buffer or file."
 116   :type 'hook
 117   :group 'view)
 118 \f
 119 (defvar view-old-buffer-read-only nil)
 120 (make-variable-buffer-local 'view-old-buffer-read-only)
 121
 122 (defvar view-old-Helper-return-blurb)
 123 (make-variable-buffer-local 'view-old-Helper-return-blurb)
 124
 125 ;; Just to avoid warnings.
 126 (defvar Helper-return-blurb)
 127
 128 (defvar view-page-size nil
 129   "Default number of lines to scroll by View page commands.
 130 If nil that means use the window size.")
 131 (make-variable-buffer-local 'view-page-size)
 132
 133 (defvar view-half-page-size nil
 134   "Default number of lines to scroll by View half page commands.
 135 If nil that means use half the window size.")
 136 (make-variable-buffer-local 'view-half-page-size)
 137
 138 (defvar view-last-regexp nil)
 139 (make-variable-buffer-local 'view-last-regexp) ; Global is better???
 140
 141 (defvar view-return-to-alist nil
 142   "What to do with used windows and where to go when finished viewing buffer.
 143 This is local in each buffer being viewed.
 144 It is added to by `view-mode-enter' when starting to view a buffer and
 145 subtracted from by `view-mode-exit' when finished viewing the buffer.
 146
 147 See RETURN-TO-ALIST argument of function `view-mode-exit' for the format of
 148 `view-return-to-alist'.")
 149 (make-variable-buffer-local 'view-return-to-alist)
 150 (put 'view-return-to-alist 'permanent-local t)
 151
 152 (defvar view-exit-action nil
 153   "If non-nil, a function with one argument (a buffer) called when finished viewing.
 154 Commands like \\[view-file] and \\[view-file-other-window] may
 155 set this to bury or kill the viewed buffer.
 156 Observe that the buffer viewed might not appear in any window at
 157 the time this function is called.")
 158 (make-variable-buffer-local 'view-exit-action)
 159
 160 (defvar view-no-disable-on-exit nil
 161   "If non-nil, View mode \"exit\" commands don't actually disable View mode.
 162 Instead, these commands just switch buffers or windows.
 163 This is set in certain buffers by specialized features such as help commands
 164 that use View mode automatically.")
 165
 166 (defvar view-overlay nil
 167   "Overlay used to display where a search operation found its match.
 168 This is local in each buffer, once it is used.")
 169 (make-variable-buffer-local 'view-overlay)
 170
 171 (unless (assq 'view-mode minor-mode-alist)
 172   (setq minor-mode-alist
 173         (cons (list 'view-mode
 174                     (propertize " View"
 175                                 'local-map mode-line-minor-mode-keymap
 176                                 'help-echo "mouse-3: minor mode menu"))
 177               minor-mode-alist)))
 178 \f
 179 ;; Define keymap inside defvar to make it easier to load changes.
 180 ;; Some redundant "less"-like key bindings below have been commented out.
 181 (defvar view-mode-map
 182   (let ((map (make-sparse-keymap)))
 183     (define-key map "C" 'View-kill-and-leave)
 184     (define-key map "c" 'View-leave)
 185     (define-key map "Q" 'View-quit-all)
 186     (define-key map "E" 'View-exit-and-edit)
 187 ;    (define-key map "v" 'View-exit)
 188     (define-key map "e" 'View-exit)
 189     (define-key map "q" 'View-quit)
 190 ;    (define-key map "N" 'View-search-last-regexp-backward)
 191     (define-key map "p" 'View-search-last-regexp-backward)
 192     (define-key map "n" 'View-search-last-regexp-forward)
 193 ;    (define-key map "?" 'View-search-regexp-backward) ; Less does this.
 194     (define-key map "\\" 'View-search-regexp-backward)
 195     (define-key map "/" 'View-search-regexp-forward)
 196     (define-key map "r" 'isearch-backward)
 197     (define-key map "s" 'isearch-forward)
 198     (define-key map "m" 'point-to-register)
 199     (define-key map "'" 'register-to-point)
 200     (define-key map "x" 'exchange-point-and-mark)
 201     (define-key map "@" 'View-back-to-mark)
 202     (define-key map "." 'set-mark-command)
 203     (define-key map "%" 'View-goto-percent)
 204 ;    (define-key map "G" 'View-goto-line-last)
 205     (define-key map "g" 'View-goto-line)
 206     (define-key map "=" 'what-line)
 207     (define-key map "F" 'View-revert-buffer-scroll-page-forward)
 208 ;    (define-key map "k" 'View-scroll-line-backward)
 209     (define-key map "y" 'View-scroll-line-backward)
 210 ;    (define-key map "j" 'View-scroll-line-forward)
 211     (define-key map "\n" 'View-scroll-line-forward)
 212     (define-key map "\r" 'View-scroll-line-forward)
 213     (define-key map "u" 'View-scroll-half-page-backward)
 214     (define-key map "d" 'View-scroll-half-page-forward)
 215     (define-key map "z" 'View-scroll-page-forward-set-page-size)
 216     (define-key map "w" 'View-scroll-page-backward-set-page-size)
 217 ;    (define-key map "b" 'View-scroll-page-backward)
 218     (define-key map "\C-?" 'View-scroll-page-backward)
 219 ;    (define-key map "f" 'View-scroll-page-forward)
 220     (define-key map " " 'View-scroll-page-forward)
 221     (define-key map "o" 'View-scroll-to-buffer-end)
 222     (define-key map ">" 'end-of-buffer)
 223     (define-key map "<" 'beginning-of-buffer)
 224     (define-key map "-" 'negative-argument)
 225     (define-key map "9" 'digit-argument)
 226     (define-key map "8" 'digit-argument)
 227     (define-key map "7" 'digit-argument)
 228     (define-key map "6" 'digit-argument)
 229     (define-key map "5" 'digit-argument)
 230     (define-key map "4" 'digit-argument)
 231     (define-key map "3" 'digit-argument)
 232     (define-key map "2" 'digit-argument)
 233     (define-key map "1" 'digit-argument)
 234     (define-key map "0" 'digit-argument)
 235     (define-key map "H" 'describe-mode)
 236     (define-key map "?" 'describe-mode) ; Maybe do as less instead? See above.
 237     (define-key map "h" 'describe-mode)
 238     map))
 239
 240 (or (assq 'view-mode minor-mode-map-alist)
 241     (setq minor-mode-map-alist
 242           (cons (cons 'view-mode view-mode-map) minor-mode-map-alist)))
 243 \f
 244 ;;; Commands that enter or exit view mode.
 245
 246 ;; This is used when view mode is exited, to make sure we don't try to
 247 ;; kill a buffer modified by the user.  A buffer in view mode can
 248 ;; become modified if the user types C-x C-q, edits the buffer, then
 249 ;; types C-x C-q again to return to view mode.
 250 ;;;###autoload
 251 (defun kill-buffer-if-not-modified (buf)
 252   "Like `kill-buffer', but does nothing if the buffer is modified."
 253   (let ((buf (get-buffer buf)))
 254     (and buf (not (buffer-modified-p buf))
 255          (kill-buffer buf))))
 256
 257 ;;;###autoload
 258 (defun view-file (file)
 259   "View FILE in View mode, returning to previous buffer when done.
 260 Emacs commands editing the buffer contents are not available; instead, a
 261 special set of commands (mostly letters and punctuation) are defined for
 262 moving around in the buffer.
 263 Space scrolls forward, Delete scrolls backward.
 264 For a list of all View commands, type H or h while viewing.
 265
 266 This command runs the normal hook `view-mode-hook'."
 267   (interactive "fView file: ")
 268   (unless (file-exists-p file) (error "%s does not exist" file))
 269   (let ((had-a-buf (get-file-buffer file))
 270         (buffer (find-file-noselect file)))
 271     (if (eq (with-current-buffer buffer
 272               (get major-mode 'mode-class))
 273             'special)
 274         (progn
 275           (switch-to-buffer buffer)
 276           (message "Not using View mode because the major mode is special"))
 277       (view-buffer buffer (and (not had-a-buf) 'kill-buffer-if-not-modified)))))
 278
 279 ;;;###autoload
 280 (defun view-file-other-window (file)
 281   "View FILE in View mode in another window.
 282 When done, return that window to its previous buffer, and kill the
 283 buffer visiting FILE if unmodified and if it wasn't visited before.
 284
 285 Emacs commands editing the buffer contents are not available; instead,
 286 a special set of commands (mostly letters and punctuation)
 287 are defined for moving around in the buffer.
 288 Space scrolls forward, Delete scrolls backward.
 289 For a list of all View commands, type H or h while viewing.
 290
 291 This command runs the normal hook `view-mode-hook'."
 292   (interactive "fIn other window view file: ")
 293   (unless (file-exists-p file) (error "%s does not exist" file))
 294   (let ((had-a-buf (get-file-buffer file))
 295         (buf-to-view (find-file-noselect file)))
 296     (view-buffer-other-window buf-to-view nil
 297                               (and (not had-a-buf)
 298                                    'kill-buffer-if-not-modified))))
 299
 300 ;;;###autoload
 301 (defun view-file-other-frame (file)
 302   "View FILE in View mode in another frame.
 303 When done, kill the buffer visiting FILE if unmodified and if it wasn't
 304 visited before; also, maybe delete other frame and/or return to previous
 305 buffer.
 306
 307 Emacs commands editing the buffer contents are not available; instead,
 308 a special set of commands (mostly letters and punctuation)
 309 are defined for moving around in the buffer.
 310 Space scrolls forward, Delete scrolls backward.
 311 For a list of all View commands, type H or h while viewing.
 312
 313 This command runs the normal hook `view-mode-hook'."
 314   (interactive "fIn other frame view file: ")
 315   (unless (file-exists-p file) (error "%s does not exist" file))
 316   (let ((had-a-buf (get-file-buffer file))
 317         (buf-to-view (find-file-noselect file)))
 318     (view-buffer-other-frame buf-to-view nil
 319                              (and (not had-a-buf)
 320                                   'kill-buffer-if-not-modified))))
 321
 322
 323 ;;;###autoload
 324 (defun view-buffer (buffer &optional exit-action)
 325   "View BUFFER in View mode, returning to previous buffer when done.
 326 Emacs commands editing the buffer contents are not available; instead, a
 327 special set of commands (mostly letters and punctuation) are defined for
 328 moving around in the buffer.
 329 Space scrolls forward, Delete scrolls backward.
 330 For a list of all View commands, type H or h while viewing.
 331
 332 This command runs the normal hook `view-mode-hook'.
 333
 334 Optional argument EXIT-ACTION is either nil or a function with buffer as
 335 argument.  This function is called when finished viewing buffer.  Use
 336 this argument instead of explicitly setting `view-exit-action'.
 337
 338 Do not set EXIT-ACTION to `kill-buffer' when BUFFER visits a
 339 file: Users may suspend viewing in order to modify the buffer.
 340 Exiting View mode will then discard the user's edits.  Setting
 341 EXIT-ACTION to `kill-buffer-if-not-modified' avoids this."
 342   (interactive "bView buffer: ")
 343   (let ((undo-window (list (window-buffer) (window-start) (window-point))))
 344     (switch-to-buffer buffer)
 345     (view-mode-enter (cons (selected-window) (cons nil undo-window))
 346                      exit-action)))
 347
 348 ;;;###autoload
 349 (defun view-buffer-other-window (buffer &optional not-return exit-action)
 350   "View BUFFER in View mode in another window.
 351 Return to previous buffer when done, unless optional NOT-RETURN is
 352 non-nil.  Emacs commands editing the buffer contents are not available;
 353 instead, a special set of commands (mostly letters and punctuation) are
 354 defined for moving around in the buffer.
 355 Space scrolls forward, Delete scrolls backward.
 356 For a list of all View commands, type H or h while viewing.
 357
 358 This command runs the normal hook `view-mode-hook'.
 359
 360 Optional argument EXIT-ACTION is either nil or a function with buffer as
 361 argument.  This function is called when finished viewing buffer.  Use
 362 this argument instead of explicitly setting `view-exit-action'."
 363   (interactive "bIn other window view buffer:\nP")
 364   (let* ((win                           ; This window will be selected by
 365           (get-lru-window))             ; switch-to-buffer-other-window below.
 366          (return-to
 367           (and (not not-return)
 368                (cons (selected-window)
 369                      (if (eq win (selected-window))
 370                          t                      ; Has to make new window.
 371                        (list
 372                         (window-buffer win)     ; Other windows old buffer.
 373                         (window-start win)
 374                         (window-point win)))))))
 375     (switch-to-buffer-other-window buffer)
 376     (view-mode-enter (and return-to (cons (selected-window) return-to))
 377                      exit-action)))
 378
 379 ;;;###autoload
 380 (defun view-buffer-other-frame (buffer &optional not-return exit-action)
 381   "View BUFFER in View mode in another frame.
 382 Return to previous buffer when done, unless optional NOT-RETURN is
 383 non-nil.  Emacs commands editing the buffer contents are not available;
 384 instead, a special set of commands (mostly letters and punctuation) are
 385 defined for moving around in the buffer.
 386 Space scrolls forward, Delete scrolls backward.
 387 For a list of all View commands, type H or h while viewing.
 388
 389 This command runs the normal hook `view-mode-hook'.
 390
 391 Optional argument EXIT-ACTION is either nil or a function with buffer as
 392 argument.  This function is called when finished viewing buffer.  Use
 393 this argument instead of explicitly setting `view-exit-action'."
 394   (interactive "bView buffer in other frame: \nP")
 395   (let ((return-to
 396          (and (not not-return) (cons (selected-window) t)))) ; Old window.
 397     (switch-to-buffer-other-frame buffer)
 398     (view-mode-enter (and return-to (cons (selected-window) return-to))
 399                      exit-action)))
 400 \f
 401 ;;;###autoload
 402 (defun view-mode (&optional arg)
 403   ;; In the following documentation string we have to use some explicit key
 404   ;; bindings instead of using the \\[] construction.  The reason for this
 405   ;; is that most commands have more than one key binding.
 406   "Toggle View mode, a minor mode for viewing text but not editing it.
 407 With prefix argument ARG, turn View mode on if ARG is positive, otherwise
 408 turn it off.
 409
 410 Emacs commands that do not change the buffer contents are available as usual.
 411 Kill commands insert text in kill buffers but do not delete.  Other commands
 412 \(among them most letters and punctuation) beep and tell that the buffer is
 413 read-only.
 414 \\<view-mode-map>
 415 The following additional commands are provided.  Most commands take prefix
 416 arguments.  Page commands default to \"page size\" lines which is almost a whole
 417 window full, or number of lines set by \\[View-scroll-page-forward-set-page-size] or \\[View-scroll-page-backward-set-page-size].  Half page commands default to
 418 and set \"half page size\" lines which initially is half a window full.  Search
 419 commands default to a repeat count of one.
 420
 421 H, h, ?  This message.
 422 Digits  provide prefix arguments.
 423 \\[negative-argument]   negative prefix argument.
 424 \\[beginning-of-buffer] move to the beginning of buffer.
 425 >       move to the end of buffer.
 426 \\[View-scroll-to-buffer-end]   scroll so that buffer end is at last line of window.
 427 SPC     scroll forward \"page size\" lines.
 428           With prefix scroll forward prefix lines.
 429 DEL     scroll backward \"page size\" lines.
 430           With prefix scroll backward prefix lines.
 431 \\[View-scroll-page-forward-set-page-size]      like  \\[View-scroll-page-forward]  but with prefix sets \"page size\" to prefix.
 432 \\[View-scroll-page-backward-set-page-size]     like  \\[View-scroll-page-backward]  but with prefix sets \"page size\" to prefix.
 433 \\[View-scroll-half-page-forward]       scroll forward \"half page size\" lines.  With prefix, sets
 434           \"half page size\" to prefix lines and scrolls forward that much.
 435 \\[View-scroll-half-page-backward]      scroll backward \"half page size\" lines.  With prefix, sets
 436           \"half page size\" to prefix lines and scrolls backward that much.
 437 RET, LFD  scroll forward one line.  With prefix scroll forward prefix line(s).
 438 y       scroll backward one line.  With prefix scroll backward prefix line(s).
 439 \\[View-revert-buffer-scroll-page-forward]      revert-buffer if necessary and scroll forward.
 440           Use this to view a changing file.
 441 \\[what-line]   prints the current line number.
 442 \\[View-goto-percent]   goes prefix argument (default 100) percent into buffer.
 443 \\[View-goto-line]      goes to line given by prefix argument (default first line).
 444 .       set the mark.
 445 x       exchanges point and mark.
 446 \\[View-back-to-mark]   return to mark and pops mark ring.
 447           Mark ring is pushed at start of every successful search and when
 448           jump to line occurs.  The mark is set on jump to buffer start or end.
 449 \\[point-to-register]   save current position in character register.
 450 '       go to position saved in character register.
 451 s       do forward incremental search.
 452 r       do reverse incremental search.
 453 \\[View-search-regexp-forward]  searches forward for regular expression, starting after current page.
 454           ! and @ have a special meaning at the beginning of the regexp.
 455           ! means search for a line with no match for regexp.  @ means start
 456           search at beginning (end for backward search) of buffer.
 457 \\      searches backward for regular expression, starting before current page.
 458 \\[View-search-last-regexp-forward]     searches forward for last regular expression.
 459 p       searches backward for last regular expression.
 460 \\[View-quit]   quit View mode, restoring this window and buffer to previous state.
 461           \\[View-quit] is the normal way to leave view mode.
 462 \\[View-exit]   exit View mode but stay in current buffer.  Use this if you started
 463           viewing a buffer (file) and find out you want to edit it.
 464           This command restores the previous read-only status of the buffer.
 465 \\[View-exit-and-edit]  exit View mode, and make the current buffer editable
 466           even if it was not editable before entry to View mode.
 467 \\[View-quit-all]       quit View mode, restoring all windows to previous state.
 468 \\[View-leave]  quit View mode and maybe switch buffers, but don't kill this buffer.
 469 \\[View-kill-and-leave] quit View mode, kill current buffer and go back to other buffer.
 470
 471 The effect of \\[View-leave], \\[View-quit] and \\[View-kill-and-leave] depends on how view-mode was entered.  If it was
 472 entered by view-file, view-file-other-window, view-file-other-frame, or
 473 \\[dired-view-file] \(\\[view-file], \\[view-file-other-window],
 474 \\[view-file-other-frame], or the Dired mode v command),
 475 then \\[View-quit] will try to kill the current buffer.
 476 If view-mode was entered from another buffer, by \\[view-buffer],
 477 \\[view-buffer-other-window], \\[view-buffer-other frame], \\[view-file],
 478 \\[view-file-other-window], or \\[view-file-other-frame],
 479 then \\[View-leave], \\[View-quit] and \\[View-kill-and-leave] will return to that buffer.
 480
 481 Entry to view-mode runs the normal hook `view-mode-hook'."
 482   (interactive "P")
 483   (unless (and arg                      ; Do nothing if already OK.
 484                (if (> (prefix-numeric-value arg) 0) view-mode (not view-mode)))
 485     (if view-mode (view-mode-disable)
 486       (view-mode-enable))))
 487 \f
 488 (defun view-mode-enable ()
 489   "Turn on View mode."
 490   ;; Always leave view mode before changing major mode.
 491   ;; This is to guarantee that the buffer-read-only variable is restored.
 492   (add-hook 'change-major-mode-hook 'view-mode-disable nil t)
 493   (setq view-mode t
 494         view-page-size nil
 495         view-half-page-size nil
 496         view-old-buffer-read-only buffer-read-only
 497         buffer-read-only t
 498         view-old-Helper-return-blurb (and (boundp 'Helper-return-blurb)
 499                                           Helper-return-blurb)
 500         Helper-return-blurb
 501         (format "continue viewing %s"
 502                 (if (buffer-file-name)
 503                     (file-name-nondirectory (buffer-file-name))
 504                   (buffer-name))))
 505   (force-mode-line-update)
 506   (run-hooks 'view-mode-hook))
 507
 508 (defun view-mode-disable ()
 509   "Turn off View mode."
 510   (remove-hook 'change-major-mode-hook 'view-mode-disable t)
 511   (and view-overlay (delete-overlay view-overlay))
 512   (force-mode-line-update)
 513   ;; Calling toggle-read-only while View mode is enabled
 514   ;; sets view-read-only to t as a buffer-local variable
 515   ;; after exiting View mode.  That arranges that the next toggle-read-only
 516   ;; will reenable View mode.
 517   ;; Cancelling View mode in any other way should cancel that, too,
 518   ;; so that View mode stays off if toggle-read-only is called.
 519   (if (local-variable-p 'view-read-only)
 520       (kill-local-variable 'view-read-only))
 521   (setq view-mode nil
 522         Helper-return-blurb view-old-Helper-return-blurb)
 523   (if buffer-read-only
 524       (setq buffer-read-only view-old-buffer-read-only)))
 525
 526 ;;;###autoload
 527 (defun view-return-to-alist-update (buffer &optional item)
 528   "Update `view-return-to-alist' of buffer BUFFER.
 529 Remove from `view-return-to-alist' all entries referencing dead
 530 windows.  Optional argument ITEM non-nil means add ITEM to
 531 `view-return-to-alist' after purging.  For a decsription of items
 532 that can be added see the RETURN-TO-ALIST argument of the
 533 function `view-mode-exit'.  If `view-return-to-alist' contains an
 534 entry for the selected window, purge that entry from
 535 `view-return-to-alist' before adding ITEM."
 536   (with-current-buffer buffer
 537     (when view-return-to-alist
 538       (let* ((list view-return-to-alist)
 539              entry entry-window last)
 540         (while list
 541           (setq entry (car list))
 542           (setq entry-window (car entry))
 543           (if (and (windowp entry-window)
 544                    (or (and item (eq entry-window (selected-window)))
 545                        (not (window-live-p entry-window))))
 546               ;; Remove that entry.
 547               (if last
 548                   (setcdr last (cdr list))
 549                 (setq view-return-to-alist
 550                       (cdr view-return-to-alist)))
 551             ;; Leave entry alone.
 552             (setq last entry))
 553           (setq list (cdr list)))))
 554     ;; Add ITEM.
 555     (when item
 556       (setq view-return-to-alist
 557             (cons item view-return-to-alist)))))
 558
 559 ;;;###autoload
 560 (defun view-mode-enter (&optional return-to exit-action)
 561   "Enter View mode and set up exit from view mode depending on optional arguments.
 562 RETURN-TO non-nil means add RETURN-TO as an element to the buffer
 563 local alist `view-return-to-alist'.  Save EXIT-ACTION in buffer
 564 local variable `view-exit-action'.  It should be either nil or a
 565 function that takes a buffer as argument.  This function will be
 566 called by `view-mode-exit'.
 567
 568 RETURN-TO is either nil, meaning do nothing when exiting view
 569 mode, or must have the format (WINDOW OLD-WINDOW . OLD-BUF-INFO).
 570 WINDOW is the window used for viewing.  OLD-WINDOW is nil or the
 571 window to select after viewing.  OLD-BUF-INFO tells what to do
 572 with WINDOW when exiting.  It is one of:
 573 1) nil            Do nothing.
 574 2) t              Delete WINDOW or, if it is the only window and
 575                   `view-remove-frame-by-deleting' is non-nil, its
 576                   frame.
 577 3) (OLD-BUFF START POINT)  Display buffer OLD-BUFF with displayed text
 578                   starting at START and point at POINT in WINDOW.
 579 4) quit-window    Do `quit-window' in WINDOW.
 580 5) keep-frame     Like case 2) but do not delete the frame.
 581
 582 For a list of all View commands, type H or h while viewing.
 583
 584 This function runs the normal hook `view-mode-hook'."
 585   (when return-to
 586     (let ((entry (assq (car return-to) view-return-to-alist)))
 587       (if entry
 588           (setcdr entry (cdr return-to))
 589         (setq view-return-to-alist (cons return-to view-return-to-alist)))))
 590   (when exit-action
 591     (setq view-exit-action exit-action))
 592
 593   (unless view-mode
 594     (view-mode-enable)
 595     (force-mode-line-update)
 596     (unless view-inhibit-help-message
 597       (message "%s"
 598                (substitute-command-keys "\
 599 View mode: type \\[help-command] for help, \\[describe-mode] for commands, \\[View-quit] to quit.")))))
 600 \f
 601 (defun view-mode-exit (&optional return-to-alist exit-action all-win)
 602   "Exit View mode in various ways, depending on optional arguments.
 603 RETURN-TO-ALIST, EXIT-ACTION and ALL-WIN determine what to do
 604 after exit.  EXIT-ACTION is nil or a function that is called with
 605 current buffer as argument.
 606
 607 RETURN-TO-ALIST is an alist that, for some of the windows
 608 displaying the current buffer, maintains information on what to
 609 do when exiting those windows.  If ALL-WIN is non-nil or the
 610 variable `view-exits-all-viewing-windows' is non-nil,
 611 view-mode-exit attempts to restore all windows showing the
 612 current buffer to their old state.  Otherwise, only the selected
 613 window is affected (provided it is on RETURN-TO-ALIST).
 614
 615 Elements of RETURN-TO-ALIST must have the format
 616   (WINDOW OLD-WINDOW . OLD-BUF-INFO) where
 617
 618 WINDOW is a window displaying the current buffer and OLD-WINDOW
 619 is either nil or a window to select after viewing.  OLD-BUF-INFO
 620 provides information on what to do with WINDOW and may be one of:
 621 1) nil            Do nothing.
 622 2) t              Delete WINDOW and, if it is the only window and
 623                   `view-remove-frame-by-deleting' is non-nil, its
 624                   frame.
 625 3) (OLD-BUF START POINT)  Display buffer OLD-BUF with displayed text
 626                   starting at START and point at POINT in WINDOW.
 627 4) quit-window    Do `quit-window' in WINDOW.
 628 5) keep-frame     Like case 2) but do not delete the frame.
 629
 630 If one of the WINDOW in RETURN-TO-ALIST is the selected window
 631 and the corresponding OLD-WINDOW is a live window, then select
 632 OLD-WINDOW."
 633   (when view-mode                   ; Only do something if in view mode.
 634     (setq all-win
 635           (and return-to-alist
 636                (or all-win view-exits-all-viewing-windows)))
 637     (let* ((buffer (current-buffer))
 638            window notlost
 639            (sel-old (assq (selected-window) return-to-alist))
 640            (alist (cond
 641                    (all-win                ; Try to restore all windows.
 642                     (append return-to-alist nil)) ; Copy.
 643                    (sel-old                     ; Only selected window.
 644                     (list sel-old))))
 645            (old-window (if sel-old (car (cdr sel-old)))))
 646       (if all-win                        ; Follow chains of old-windows.
 647           (let ((c (length alist)) a)
 648             (while (and (> c 0)   ; Safety if mutually refering windows.
 649                         (or (not (window-live-p old-window))
 650                             (eq buffer (window-buffer old-window)))
 651                         (setq a (assq old-window alist)))
 652               (setq c (1- c))
 653               (setq old-window (car (cdr a))))
 654             (if (or (zerop c) (not (window-live-p old-window)))
 655                 (setq old-window (selected-window)))))
 656       (unless view-no-disable-on-exit
 657         (view-mode-disable))
 658       (while alist                          ; Restore windows with info.
 659         (setq notlost nil)
 660         (when (and (window-live-p (setq window (car (car alist))))
 661                    (eq buffer (window-buffer window)))
 662           (let ((frame (window-frame window))
 663                 (old-buf-info (cdr (cdr (car alist)))))
 664             (if all-win (select-window window))
 665             (cond
 666              ((and (consp old-buf-info)         ; Case 3.
 667                    (buffer-live-p (car old-buf-info)))
 668               (set-window-buffer window (car old-buf-info)) ; old-buf
 669               (set-window-start window (car (cdr old-buf-info)))
 670               (set-window-point window (car (cdr (cdr old-buf-info)))))
 671              ((eq old-buf-info 'quit-window)
 672               (quit-window))                    ; Case 4.
 673              (old-buf-info                      ; Case 2 or 5.
 674               (cond
 675                ((not (one-window-p t))          ; Not only window.
 676                 (delete-window))
 677                ((eq old-buf-info 'keep-frame)   ; Case 5.
 678                 (bury-buffer))
 679                ((not (eq frame (next-frame)))  ; Case 2 and only window.
 680                 ;; Not the only frame, so can safely be removed.
 681                 (if view-remove-frame-by-deleting
 682                     (delete-frame frame)
 683                   (setq notlost t)         ; Keep the window. See below.
 684                   (iconify-frame frame))))))))
 685         ;; If a frame is removed by iconifying it, the window is not
 686         ;; really lost.  In this case we keep the entry in
 687         ;; `view-return-to-alist' so that if the user deiconifies the
 688         ;; frame and then hits q, the frame is iconified again.
 689         (unless notlost
 690           (with-current-buffer buffer
 691             (setq view-return-to-alist
 692                   (delete (car alist) view-return-to-alist))))
 693         (setq alist (cdr alist)))
 694       (when (window-live-p old-window)
 695         ;; old-window is still alive => select it.
 696         (select-window old-window))
 697       (when exit-action
 698         ;; Don't do that: If the user wants to quit the *Help* buffer a
 699         ;; second time it won't have any effect.
 700 ;;;     (setq view-exit-action nil)
 701         (funcall exit-action buffer))
 702       (force-mode-line-update))))
 703 \f
 704 (defun View-exit ()
 705   "Exit View mode but stay in current buffer."
 706   (interactive)
 707   (view-mode-exit))
 708
 709 ;;;###autoload
 710 (defun View-exit-and-edit ()
 711   "Exit View mode and make the current buffer editable."
 712   (interactive)
 713   (let ((view-old-buffer-read-only nil)
 714         (view-no-disable-on-exit nil))
 715     (view-mode-exit)))
 716
 717 (defun View-leave ()
 718   "Quit View mode and maybe switch buffers, but don't kill this buffer."
 719   (interactive)
 720   (view-mode-exit view-return-to-alist))
 721
 722 (defun View-quit ()
 723   "Quit View mode, trying to restore window and buffer to previous state.
 724 Maybe kill this buffer.  Try to restore selected window to previous state
 725 and go to previous buffer or window."
 726   (interactive)
 727   (view-mode-exit view-return-to-alist view-exit-action))
 728
 729 (defun View-quit-all ()
 730   "Quit View mode, trying to restore windows and buffers to previous state.
 731 Maybe kill current buffer.  Try to restore all windows viewing buffer to
 732 previous state and go to previous buffer or window."
 733   (interactive)
 734   (view-mode-exit view-return-to-alist view-exit-action t))
 735
 736 (defun View-kill-and-leave ()
 737   "Quit View mode, kill current buffer and return to previous buffer."
 738   (interactive)
 739   (view-mode-exit view-return-to-alist (or view-exit-action 'kill-buffer) t))
 740 \f
 741
 742 ;;; Some help routines.
 743
 744 (defun view-window-size ()
 745   ;; Window height excluding mode line.
 746   (1- (window-height)))
 747
 748 ;(defun view-last-command (&optional who what)
 749 ;  (setq view-last-command-entry this-command)
 750 ;  (setq view-last-command who)
 751 ;  (setq view-last-command-argument what))
 752
 753 ;(defun View-repeat-last-command ()
 754 ;  "Repeat last command issued in View mode."
 755 ;  (interactive)
 756 ;  (if (and view-last-command
 757 ;          (eq view-last-command-entry last-command))
 758 ;      (funcall view-last-command view-last-command-argument))
 759 ;  (setq this-command view-last-command-entry))
 760
 761 (defun view-recenter ()
 762   ;; Center point in window.
 763   (recenter (/ (view-window-size) 2)))
 764
 765 (defun view-page-size-default (lines)
 766   ;; Get page size.
 767   (let ((default (- (view-window-size) next-screen-context-lines)))
 768     (if (or (null lines) (zerop (setq lines (prefix-numeric-value lines))))
 769         default
 770       (min (abs lines) default))))
 771
 772 (defun view-set-half-page-size-default (lines)
 773   ;; Get and maybe set half page size.
 774   (if (not lines) (or view-half-page-size
 775                       (/ (view-window-size) 2))
 776     (setq view-half-page-size
 777           (if (zerop (setq lines (prefix-numeric-value lines)))
 778               (/ (view-window-size) 2)
 779             (view-page-size-default lines)))))
 780
 781
 782 ;;; Commands for moving around in the buffer.
 783
 784 (defun View-goto-percent (&optional percent)
 785   "Move to end (or prefix PERCENT) of buffer in View mode.
 786 Display is centered at point.
 787 Also set the mark at the position where point was."
 788   (interactive "P")
 789   (push-mark)
 790   (goto-char
 791    (if percent
 792        (+ (point-min)
 793           (floor (* (- (point-max) (point-min)) 0.01
 794                     (max 0 (min 100 (prefix-numeric-value percent))))))
 795      (point-max)))
 796   (view-recenter))
 797
 798 ;(defun View-goto-line-last (&optional line)
 799 ;"Move to last (or prefix LINE) line in View mode.
 800 ;Display is centered at LINE.
 801 ;Sets mark at starting position and pushes mark ring."
 802 ;  (interactive "P")
 803 ;  (push-mark)
 804 ;  (if line (goto-line (prefix-numeric-value line))
 805 ;    (goto-char (point-max))
 806 ;    (beginning-of-line))
 807 ;  (view-recenter))
 808
 809 (defun View-goto-line (&optional line)
 810   "Move to first (or prefix LINE) line in View mode.
 811 Display is centered at LINE.
 812 Also set the mark at the position where point was."
 813   (interactive "p")
 814   (push-mark)
 815   (goto-line line)
 816   (view-recenter))
 817
 818 (defun View-back-to-mark (&optional ignore)
 819   "Return to last mark set in View mode, else beginning of file.
 820 Display that line at the center of the window.
 821 This command pops the mark ring, so that successive
 822 invocations return to earlier marks."
 823   (interactive)
 824   (goto-char (or (mark t) (point-min)))
 825   (pop-mark)
 826   (view-recenter))
 827 \f
 828 (defun view-scroll-lines (lines backward default maxdefault)
 829   ;; This function does the job for all the scrolling commands.
 830   ;; Scroll forward LINES lines.  If BACKWARD is true scroll backwards.
 831   ;; If LINES is negative scroll in the other direction.  If LINES is 0 or nil,
 832   ;; scroll DEFAULT lines.  If MAXDEFAULT is true then scroll no more than a
 833   ;; window full.
 834   (if (or (null lines) (zerop (setq lines (prefix-numeric-value lines))))
 835       (setq lines default))
 836   (when (< lines 0)
 837     (setq backward (not backward)) (setq lines (- lines)))
 838   (setq default (view-page-size-default nil)) ; Max scrolled at a time.
 839   (if maxdefault (setq lines (min lines default)))
 840   (cond
 841    (backward (scroll-down lines))
 842    ((view-really-at-end)
 843     (if view-scroll-auto-exit (View-quit)
 844       (ding)
 845       (view-end-message)))
 846    (t (while (> lines default)
 847         (scroll-up default)
 848         (setq lines (- lines default))
 849         (if (view-really-at-end) (setq lines 0)))
 850       (scroll-up lines)
 851       (if (view-really-at-end) (view-end-message))
 852       (move-to-window-line -1)
 853       (beginning-of-line))))
 854
 855 (defun view-really-at-end ()
 856   ;; Return true if buffer end visible.  Maybe revert buffer and test.
 857   (and (pos-visible-in-window-p (point-max))
 858        (let ((buf (current-buffer))
 859              (bufname (buffer-name))
 860              (file (buffer-file-name)))
 861          (or (not view-try-extend-at-buffer-end)
 862              (null file)
 863              (verify-visited-file-modtime buf)
 864              (not (file-exists-p file))
 865              (when (buffer-modified-p buf)
 866                (setq file (file-name-nondirectory file))
 867                (not (yes-or-no-p
 868                      (format
 869                       "File %s changed on disk.  Discard your edits%s? "
 870                       file
 871                       (if (string= bufname file) ""
 872                         (concat " in " bufname))))))
 873              (progn
 874                (revert-buffer t t t)
 875                (pos-visible-in-window-p (point-max)))))))
 876
 877 (defun view-end-message ()
 878   ;; Tell that we are at end of buffer.
 879   (goto-char (point-max))
 880   (if view-return-to-alist
 881       (message "End of buffer.  Type %s to quit viewing."
 882                (substitute-command-keys
 883                 (if view-scroll-auto-exit "\\[View-scroll-page-forward]"
 884                   "\\[View-quit]")))
 885     (message "End of buffer")))
 886 \f
 887 (defun View-scroll-to-buffer-end ()
 888   "Scroll backward or forward so that buffer end is at last line of window."
 889   (interactive)
 890   (let ((p (if (pos-visible-in-window-p (point-max)) (point))))
 891     (goto-char (point-max))
 892     (recenter -1)
 893     (and p (goto-char p))))
 894
 895 (defun View-scroll-page-forward (&optional lines)
 896   "Scroll \"page size\" or prefix LINES lines forward in View mode.
 897 Exit if end of text is visible and `view-scroll-auto-exit' is non-nil.
 898 \"page size\" is whole window full, or number of lines set by
 899 \\[View-scroll-page-forward-set-page-size] or
 900 \\[View-scroll-page-backward-set-page-size].
 901 If LINES is more than a window-full, only the last window-full is shown."
 902   (interactive "P")
 903   (view-scroll-lines lines nil (view-page-size-default view-page-size) nil))
 904
 905 (defun View-scroll-page-backward (&optional lines)
 906   "Scroll \"page size\" or prefix LINES lines backward in View mode.
 907 See also `View-scroll-page-forward'."
 908   (interactive "P")
 909   (view-scroll-lines lines t (view-page-size-default view-page-size) nil))
 910
 911 (defun View-scroll-page-forward-set-page-size (&optional lines)
 912   "Scroll forward LINES lines in View mode, setting the \"page size\".
 913 This is the number of lines which \\[View-scroll-page-forward] and
 914 \\[View-scroll-page-backward] scroll by default.
 915 If LINES is omitted or = 0, sets \"page size\" to window height and
 916 scrolls forward that much, otherwise scrolls forward LINES lines and sets
 917 \"page size\" to the minimum of window height and the absolute value of LINES.
 918 See also `View-scroll-page-forward'."
 919   (interactive "P")
 920   (view-scroll-lines lines nil
 921                      (setq view-page-size (view-page-size-default lines))
 922                      nil))
 923
 924 (defun View-scroll-page-backward-set-page-size (&optional lines)
 925   "Scroll backward prefix LINES lines in View mode, setting the \"page size\".
 926 See also `View-scroll-page-forward-set-page-size'."
 927   (interactive "P")
 928   (view-scroll-lines lines t
 929                      (setq view-page-size (view-page-size-default lines))
 930                      nil))
 931
 932 (defun View-scroll-line-forward (&optional lines)
 933   "Scroll forward one line (or prefix LINES lines) in View mode.
 934 See also `View-scroll-page-forward,' but note that scrolling is limited
 935 to minimum of LINES and one window-full."
 936   (interactive "P")
 937   (view-scroll-lines lines nil 1 t))
 938
 939 (defun View-scroll-line-backward (&optional lines)
 940   "Scroll backward one line (or prefix LINES lines) in View mode.
 941 See also `View-scroll-line-forward'."
 942   (interactive "P")
 943   (view-scroll-lines lines t 1 t))
 944
 945 (defun View-scroll-half-page-forward (&optional lines)
 946   "Scroll forward a \"half page\" (or prefix LINES) lines in View mode.
 947 If LINES is not omitted, the \"half page size\" is set to the minimum of
 948 window height and the absolute value of LINES.
 949 LINES=0 resets \"half page size\" to half window height."
 950   (interactive "P")
 951   (view-scroll-lines lines nil (view-set-half-page-size-default lines) t))
 952
 953 (defun View-scroll-half-page-backward (&optional lines)
 954   "Scroll backward a \"half page\" (or prefix LINES) lines in View mode.
 955 See also `View-scroll-half-page-forward'."
 956   (interactive "P")
 957   (view-scroll-lines lines t (view-set-half-page-size-default lines) t))
 958
 959 (defun View-revert-buffer-scroll-page-forward (&optional lines)
 960   "Scroll forward, reverting buffer if needed, in View mode.
 961 If buffer has not been changed and the corresponding file is newer, first
 962 revert the buffer, then scroll.
 963 This command is useful if you are viewing a changing file.
 964
 965 The prefix argument LINES says how many lines to scroll.
 966 If you don't specify a prefix argument, it uses the number of lines set by
 967 \\[View-scroll-page-forward-set-page-size] or
 968 \\[View-scroll-page-backward-set-page-size].
 969 If LINES is more than a window-full, only the last window-full is shown."
 970   (interactive "P")
 971   (let ((view-scroll-auto-exit nil)
 972         (view-try-extend-at-buffer-end t))
 973     (view-scroll-lines lines nil (view-page-size-default view-page-size) nil)))
 974 \f
 975 (defun View-search-regexp-forward (n regexp)
 976   "Search forward for first (or prefix Nth) occurrence of REGEXP in View mode.
 977
 978 Displays line found at center of window.  Sets mark at starting position and
 979 pushes mark ring.
 980
 981 Characters @ and ! are special at the beginning of REGEXP.  They modify
 982 the search rather than become part of the pattern searched for.
 983 @ means search all the buffer i.e. start search at the beginning of buffer.
 984 ! means search for a line that contains no match for the pattern.
 985 If REGEXP is empty or only consist of these control characters, then
 986 an earlier remembered REGEXP is used, otherwise REGEXP is remembered
 987 for use by later search commands.
 988
 989 The variable `view-highlight-face' controls the face that is used
 990 for highlighting the match that is found."
 991   (interactive "p\nsSearch forward (regexp): ")
 992   (view-search n regexp))
 993
 994 (defun View-search-regexp-backward (n regexp)
 995   "Search backward for first (or prefix Nth) occurrence of REGEXP in View mode.
 996
 997 Displays line found at center of window.  Sets mark at starting position and
 998 pushes mark ring.
 999
1000 Characters @ and ! are special at the beginning of REGEXP.  They modify
1001 the search rather than become part of the pattern searched for.
1002 @ means search all the buffer i.e. start search at the end of buffer.
1003 ! means search for a line that contains no match for the pattern.
1004 If REGEXP is empty or only consist of these control characters, then
1005 an earlier remembered REGEXP is used, otherwise REGEXP is remembered
1006 for use by later search commands.
1007
1008 The variable `view-highlight-face' controls the face that is used
1009 for highlighting the match that is found."
1010   (interactive "p\nsSearch backward (regexp): ")
1011   (view-search (- n) regexp))
1012
1013 (defun View-search-last-regexp-forward (n) "\
1014 Search forward for first (or prefix Nth) instance of last regexp in View mode.
1015 Displays line found at center of window.  Sets mark at starting position and
1016 pushes mark ring.
1017
1018 The variable `view-highlight-face' controls the face that is used
1019 for highlighting the match that is found."
1020   (interactive "p")
1021   (view-search n nil))
1022
1023 (defun View-search-last-regexp-backward (n) "\
1024 Search backward for first (or prefix Nth) instance of last regexp in View mode.
1025 Displays line found at center of window.  Sets mark at starting position and
1026 pushes mark ring.
1027
1028 The variable `view-highlight-face' controls the face that is used
1029 for highlighting the match that is found."
1030   (interactive "p")
1031   (view-search (- n) nil))
1032
1033 (defun view-search (times regexp)
1034   ;; This function does the job for all the View-search- commands.
1035   ;; Search for the TIMESt match for REGEXP. If TIMES is negative
1036   ;; search backwards. If REGEXP is nil use `view-last-regexp'.
1037   ;; Charcters "!" and "@" have a special meaning at the beginning of
1038   ;; REGEXP and are removed from REGEXP before the search "!" means
1039   ;; search for lines with no match for REGEXP.  "@" means search in
1040   ;; the whole buffer, don't start searching from the present point.
1041   (let (where no end ln)
1042     (cond
1043      ((and regexp (> (length regexp) 0)
1044            (or (not (memq (string-to-char regexp) '(?! ?@)))
1045                (progn
1046                  (if (member (substring regexp 0 2) '("!@" "@!"))
1047                      (setq end t no t ln 2)
1048                    (setq no (not (setq end (eq ?@ (string-to-char regexp))))
1049                          ln 1))
1050                  (> (length (setq regexp (substring regexp ln))) 0))))
1051       (setq view-last-regexp (if no (list regexp) regexp)))
1052      ((consp view-last-regexp)
1053       (setq regexp (car view-last-regexp))
1054       (unless (setq no (not no)) (setq view-last-regexp regexp)))
1055      (view-last-regexp (setq regexp view-last-regexp)
1056                        (if no (setq view-last-regexp (list regexp))))
1057      (t (error "No previous View-mode search")))
1058     (save-excursion
1059       (if end (goto-char (if (< times 0) (point-max) (point-min)))
1060         (move-to-window-line (if (< times 0) 0 -1)))
1061       (if (if no (view-search-no-match-lines times regexp)
1062             (re-search-forward regexp nil t times))
1063           (setq where (point))))
1064     (if where
1065         (progn
1066           (push-mark)
1067           (goto-char where)
1068           (if view-overlay
1069               (move-overlay view-overlay (match-beginning 0) (match-end 0))
1070             (setq view-overlay
1071                   (make-overlay (match-beginning 0) (match-end 0))))
1072           (overlay-put view-overlay 'face view-highlight-face)
1073           (beginning-of-line)
1074           (view-recenter))
1075       (message "Can't find occurrence %d of %s%s"
1076                times (if no "no " "") regexp)
1077       (sit-for 4))))
1078
1079 ;; This is the dumb approach, looking at each line.  The original
1080 ;; version of this function looked like it might have been trying to
1081 ;; do something clever, but not succeeding:
1082 ;; http://lists.gnu.org/archive/html/bug-gnu-emacs/2007-09/msg00073.html
1083 (defun view-search-no-match-lines (times regexp)
1084   "Search for the TIMESth occurrence of a line with no match for REGEXP.
1085 If such a line is found, return non-nil and set the match-data to that line.
1086 If TIMES is negative, search backwards."
1087   (let ((step (if (>= times 0) 1
1088                 (setq times (- times))
1089                 -1)))
1090     ;; Note that we do not check the current line.
1091     (while (and (> times 0)
1092                 (zerop (forward-line step)))
1093       ;; (forward-line 1) returns 0 on moving within the last line.
1094       (if (eobp)
1095           (setq times -1)
1096         (or (re-search-forward regexp (line-end-position) t)
1097             (setq times (1- times))))))
1098   (and (zerop times)
1099        (looking-at ".*")))
1100
1101 (provide 'view)
1102
1103 ;; arch-tag: 6d0ace36-1d12-4de3-8de3-1fa3231636d7
1104 ;;; view.el ends here