code.delx.au - gnu-emacs/blob - lisp/view.el

   1 ;;; view.el --- peruse file or buffer without editing.
   2
   3 ;; Copyright (C) 1985, 1989 Free Software Foundation, Inc.
   4
   5 ;; Author: K. Shane Hartman
   6 ;; Maintainer: FSF
   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 2, or (at your option)
  13 ;; 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; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; This package provides the `view' major mode documented in the Emacs
  27 ;; user's manual.
  28
  29 ;;; Code:
  30
  31 (defvar view-mode-map nil)
  32 (if view-mode-map
  33     nil
  34   (setq view-mode-map (make-keymap))
  35   (fillarray (nth 1 view-mode-map) 'View-undefined)
  36   (define-key view-mode-map "\C-c" 'view-exit)
  37   (define-key view-mode-map "\C-z" 'suspend-emacs)
  38   (define-key view-mode-map "q" 'view-exit)
  39   (define-key view-mode-map "-" 'negative-argument)
  40   (define-key view-mode-map "0" 'digit-argument)
  41   (define-key view-mode-map "1" 'digit-argument)
  42   (define-key view-mode-map "2" 'digit-argument)
  43   (define-key view-mode-map "3" 'digit-argument)
  44   (define-key view-mode-map "4" 'digit-argument)
  45   (define-key view-mode-map "5" 'digit-argument)
  46   (define-key view-mode-map "6" 'digit-argument)
  47   (define-key view-mode-map "7" 'digit-argument)
  48   (define-key view-mode-map "8" 'digit-argument)
  49   (define-key view-mode-map "9" 'digit-argument)
  50   (define-key view-mode-map "\C-u" 'universal-argument)
  51   (define-key view-mode-map "\e" nil)
  52   (define-key view-mode-map "\C-x" 'Control-X-prefix)
  53   (define-key view-mode-map "\e-" 'negative-argument)
  54   (define-key view-mode-map "\e0" 'digit-argument)
  55   (define-key view-mode-map "\e1" 'digit-argument)
  56   (define-key view-mode-map "\e2" 'digit-argument)
  57   (define-key view-mode-map "\e3" 'digit-argument)
  58   (define-key view-mode-map "\e4" 'digit-argument)
  59   (define-key view-mode-map "\e5" 'digit-argument)
  60   (define-key view-mode-map "\e6" 'digit-argument)
  61   (define-key view-mode-map "\e7" 'digit-argument)
  62   (define-key view-mode-map "\e8" 'digit-argument)
  63   (define-key view-mode-map "\e9" 'digit-argument)
  64   (define-key view-mode-map "<" 'beginning-of-buffer)
  65   (define-key view-mode-map ">" 'end-of-buffer)
  66   (define-key view-mode-map "\ev" 'View-scroll-lines-backward)
  67   (define-key view-mode-map "\C-v" 'View-scroll-lines-forward)
  68   (define-key view-mode-map " " 'View-scroll-lines-forward)
  69   (define-key view-mode-map "\177" 'View-scroll-lines-backward)
  70   (define-key view-mode-map "\n" 'View-scroll-one-more-line)
  71   (define-key view-mode-map "\r" 'View-scroll-one-more-line)
  72   (define-key view-mode-map "\C-l" 'recenter)
  73   (define-key view-mode-map "z" 'View-scroll-lines-forward-set-scroll-size)
  74   (define-key view-mode-map "g" 'View-goto-line)
  75   (define-key view-mode-map "=" 'what-line)
  76   (define-key view-mode-map "." 'set-mark-command)
  77   (define-key view-mode-map "\C-@" 'set-mark-command)
  78   (define-key view-mode-map "'" 'View-back-to-mark)
  79   (define-key view-mode-map "@" 'View-back-to-mark)
  80   (define-key view-mode-map "x" 'exchange-point-and-mark)
  81   (define-key view-mode-map "h" 'Helper-describe-bindings)
  82   (define-key view-mode-map "?" 'Helper-describe-bindings)
  83   (define-key view-mode-map (char-to-string help-char) 'Helper-help)
  84   (define-key view-mode-map "\C-n" 'next-line)
  85   (define-key view-mode-map "\C-p" 'previous-line)
  86   (define-key view-mode-map "\C-s" 'isearch-forward)
  87   (define-key view-mode-map "\C-r" 'isearch-backward)
  88   (define-key view-mode-map "s" 'isearch-forward)
  89   (define-key view-mode-map "r" 'isearch-backward)
  90   (define-key view-mode-map "/" 'View-search-regexp-forward)
  91   (define-key view-mode-map "\\" 'View-search-regexp-backward)
  92   ;; This conflicts with the standard binding of isearch-regexp-forward
  93   (define-key view-mode-map "\e\C-s" 'View-search-regexp-forward)
  94   (define-key view-mode-map "\e\C-r" 'View-search-regexp-backward)
  95   (define-key view-mode-map "n" 'View-search-last-regexp-forward)
  96   (define-key view-mode-map "p" 'View-search-last-regexp-backward)
  97   )
  98
  99
 100 ;;;###autoload
 101 (defun view-file (file-name)
 102   "View FILE in View mode, returning to previous buffer when done.
 103 The usual Emacs commands are not available; instead,
 104 a special set of commands (mostly letters and punctuation)
 105 are defined for moving around in the buffer.
 106 Space scrolls forward, Delete scrolls backward.
 107 For list of all View commands, type ? or h while viewing.
 108
 109 Calls the value of  view-hook  if that is non-nil."
 110   (interactive "fView file: ")
 111   (let ((old-buf (current-buffer))
 112         (had-a-buf (get-file-buffer file-name))
 113         (buf-to-view (find-file-noselect file-name)))
 114     (switch-to-buffer buf-to-view t)
 115     (view-mode old-buf
 116                (and (not had-a-buf) (not (buffer-modified-p buf-to-view))
 117                     'kill-buffer))))
 118
 119 ;;;###autoload
 120 (defun view-file-other-window (file-name)
 121   "View FILE in View mode in other window.
 122 Return to previous buffer when done.
 123 The usual Emacs commands are not available; instead,
 124 a special set of commands (mostly letters and punctuation)
 125 are defined for moving around in the buffer.
 126 Space scrolls forward, Delete scrolls backward.
 127 For list of all View commands, type ? or h while viewing.
 128
 129 Calls the value of  view-hook  if that is non-nil."
 130   (interactive "fView file: ")
 131   (let ((old-arrangement (current-window-configuration))
 132         (had-a-buf (get-file-buffer file-name))
 133         (buf-to-view (find-file-noselect file-name)))
 134     (switch-to-buffer-other-window buf-to-view)
 135     (view-mode old-arrangement
 136                (and (not had-a-buf) (not (buffer-modified-p buf-to-view))
 137                     'kill-buffer))))
 138
 139 ;;;###autoload
 140 (defun view-buffer (buffer-name)
 141   "View BUFFER in View mode, returning to previous buffer when done.
 142 The usual Emacs commands are not available; instead,
 143 a special set of commands (mostly letters and punctuation)
 144 are defined for moving around in the buffer.
 145 Space scrolls forward, Delete scrolls backward.
 146 For list of all View commands, type ? or h while viewing.
 147
 148 Calls the value of  view-hook  if that is non-nil."
 149   (interactive "bView buffer: ")
 150   (let ((old-buf (current-buffer)))
 151     (switch-to-buffer buffer-name t)
 152     (view-mode old-buf nil)))
 153
 154 ;;;###autoload
 155 (defun view-buffer-other-window (buffer-name not-return)
 156   "View BUFFER in View mode in another window,
 157 returning to original buffer when done  ONLY if
 158 prefix argument not-return is nil (as by default).
 159   The usual Emacs commands are not available; instead,
 160 a special set of commands (mostly letters and punctuation)
 161 are defined for moving around in the buffer.
 162 Space scrolls forward, Delete scrolls backward.
 163 For list of all View commands, type ? or h while viewing.
 164
 165 Calls the value of  view-hook  if that is non-nil."
 166   (interactive "bView buffer:\nP")
 167   (let ((return-to (and not-return (current-window-configuration))))
 168     (switch-to-buffer-other-window buffer-name)
 169     (view-mode return-to)))
 170
 171 ;;;###autoload
 172 (defun view-mode (&optional prev-buffer action)
 173   "Major mode for viewing text but not editing it.
 174 Letters do not insert themselves.  Instead these commands are provided.
 175 Most commands take prefix arguments.  Commands dealing with lines
 176 default to \"scroll size\" lines (initially size of window).
 177 Search commands default to a repeat count of one.
 178 M-< or <        move to beginning of buffer.
 179 M-> or >        move to end of buffer.
 180 C-v or Space    scroll forward lines.
 181 M-v or DEL      scroll backward lines.
 182 CR or LF        scroll forward one line (backward with prefix argument).
 183 z               like Space except set number of lines for further
 184                    scrolling commands to scroll by.
 185 C-u and Digits  provide prefix arguments.  `-' denotes negative argument.
 186 =               prints the current line number.
 187 g               goes to line given by prefix argument.
 188 / or M-C-s      searches forward for regular expression
 189 \\ or M-C-r     searches backward for regular expression.
 190 n               searches forward for last regular expression.
 191 p               searches backward for last regular expression.
 192 C-@ or .        set the mark.
 193 x               exchanges point and mark.
 194 C-s or s        do forward incremental search.
 195 C-r or r        do reverse incremental search.
 196 @ or '          return to mark and pops mark ring.
 197                   Mark ring is pushed at start of every
 198                   successful search and when jump to line to occurs.
 199                   The mark is set on jump to buffer start or end.
 200 ? or h          provide help message (list of commands).
 201 \\[Helper-help]         provides help (list of commands or description of a command).
 202 C-n             moves down lines vertically.
 203 C-p             moves upward lines vertically.
 204 C-l             recenters the screen.
 205 q or C-c        exit view-mode and return to previous buffer.
 206
 207 Entry to this mode calls the value of  view-hook  if non-nil.
 208 \\{view-mode-map}"
 209 ;  Not interactive because dangerous things happen
 210 ;  if you call it without passing a buffer as argument
 211 ;  and they are not easy to fix.
 212 ;  (interactive)
 213   (make-local-variable 'view-old-mode-line-buffer-identification)
 214   (setq view-old-mode-line-buffer-identification
 215         mode-line-buffer-identification)
 216   (make-local-variable 'view-old-buffer-read-only)
 217   (setq view-old-buffer-read-only buffer-read-only)
 218   (make-local-variable 'view-old-mode-name)
 219   (setq view-old-mode-name mode-name)
 220   (make-local-variable 'view-old-major-mode)
 221   (setq view-old-major-mode major-mode)
 222   (make-local-variable 'view-old-local-map)
 223   (setq view-old-local-map (current-local-map))
 224   (make-local-variable 'view-old-Helper-return-blurb)
 225   (setq view-old-Helper-return-blurb
 226         (and (boundp 'Helper-return-blurb) Helper-return-blurb))
 227
 228   (setq buffer-read-only t)
 229   (setq mode-line-buffer-identification
 230         (list
 231          (if (buffer-file-name)
 232              "Viewing %f"
 233            "Viewing %b")))
 234   (setq mode-name "View")
 235   (setq major-mode 'view-mode)
 236   (setq Helper-return-blurb
 237         (format "continue viewing %s"
 238                 (if (buffer-file-name)
 239                     (file-name-nondirectory (buffer-file-name))
 240                     (buffer-name))))
 241
 242   (make-local-variable 'view-exit-action)
 243   (setq view-exit-action action)
 244   (make-local-variable 'view-return-here)
 245   (setq view-return-here prev-buffer)
 246   (make-local-variable 'view-exit-position)
 247   (setq view-exit-position (point-marker))
 248
 249   (make-local-variable 'view-scroll-size)
 250   (setq view-scroll-size nil)
 251   (make-local-variable 'view-last-regexp)
 252   (setq view-last-regexp nil)
 253
 254   (beginning-of-line)
 255   (setq goal-column nil)
 256
 257   (use-local-map view-mode-map)
 258   (run-hooks 'view-hook)
 259   (view-helpful-message))
 260
 261 \f
 262 (defun view-exit ()
 263   "Exit from view-mode.
 264 If you viewed an existing buffer, that buffer returns to its previous mode.
 265 If you viewed a file that was not present in Emacs, its buffer is killed."
 266   (interactive)
 267   (setq mode-line-buffer-identification
 268         view-old-mode-line-buffer-identification)
 269   (setq major-mode view-old-major-mode)
 270   (setq mode-name view-old-mode-name)
 271   (use-local-map view-old-local-map)
 272   (setq buffer-read-only view-old-buffer-read-only)
 273
 274   (goto-char view-exit-position)
 275   (set-marker view-exit-position nil)
 276
 277   ;; Now do something to the buffer that we were viewing
 278   ;; (such as kill it).
 279   (let ((viewed-buffer (current-buffer))
 280         (action view-exit-action))
 281     (cond
 282      ((bufferp view-return-here)
 283       (switch-to-buffer view-return-here))
 284      ((window-configuration-p view-return-here)
 285       (set-window-configuration view-return-here)))
 286     (if action (funcall action viewed-buffer))))
 287
 288 (defun view-helpful-message ()
 289   (message
 290      (substitute-command-keys
 291       "Type \\[Helper-help] for help, \\[Helper-describe-bindings] for commands, \\[view-exit] to quit.")))
 292
 293 (defun View-undefined ()
 294   (interactive)
 295   (ding)
 296   (view-helpful-message))
 297
 298 (defun view-window-size () (1- (window-height)))
 299
 300 (defun view-scroll-size ()
 301   (min (view-window-size) (or view-scroll-size (view-window-size))))
 302
 303 (defvar view-hook nil
 304   "If non-nil, its value is called when viewing buffer or file.")
 305
 306 ;(defun view-last-command (&optional who what)
 307 ;  (setq view-last-command-entry this-command)
 308 ;  (setq view-last-command who)
 309 ;  (setq view-last-command-argument what))
 310
 311 ;(defun View-repeat-last-command ()
 312 ;  "Repeat last command issued in View mode."
 313 ;  (interactive)
 314 ;  (if (and view-last-command
 315 ;          (eq view-last-command-entry last-command))
 316 ;      (funcall view-last-command view-last-command-argument))
 317 ;  (setq this-command view-last-command-entry))
 318
 319 (defun View-goto-line (&optional line)
 320   "Move to LINE in View mode.
 321 Display is centered at LINE.  Sets mark at starting position and pushes
 322 mark ring."
 323   (interactive "p")
 324   (push-mark)
 325   (goto-line (or line 1))
 326   (recenter (/ (view-window-size) 2)))
 327
 328 (defun View-scroll-lines-forward (&optional lines)
 329   "Scroll forward in View mode, or exit if end of text is visible.
 330 No arg means whole window full, or number of lines set by \\[View-scroll-lines-forward-set-scroll-size].
 331 Arg is number of lines to scroll."
 332   (interactive "P")
 333   (if (pos-visible-in-window-p (point-max))
 334       (view-exit)
 335     (setq lines
 336           (if lines (prefix-numeric-value lines)
 337             (view-scroll-size)))
 338     ;; (view-last-command 'View-scroll-lines-forward lines)
 339     (if (>= lines (view-window-size))
 340         (scroll-up nil)
 341       (if (>= (- lines) (view-window-size))
 342           (scroll-down nil)
 343         (scroll-up lines)))
 344     (cond ((pos-visible-in-window-p (point-max))
 345            (goto-char (point-max))
 346            (recenter -1)
 347            (message (substitute-command-keys
 348                      "End.  Type \\[view-exit] to quit viewing."))))
 349     (move-to-window-line -1)
 350     (beginning-of-line)))
 351
 352 (defun View-scroll-lines-forward-set-scroll-size (&optional lines)
 353   "Scroll forward LINES lines in View mode, setting the \"scroll size\".
 354 This is the number of lines which \\[View-scroll-lines-forward] and \\[View-scroll-lines-backward] scroll by default.
 355 The absolute value of LINES is used, so this command can be used to scroll
 356 backwards (but \"scroll size\" is always positive).  If LINES is greater than
 357 window height or omitted, then window height is assumed.  If LINES is less
 358 than window height then scrolling context is provided from previous screen."
 359   (interactive "P")
 360   (if (not lines)
 361       (setq view-scroll-size (view-window-size))
 362     (setq lines (prefix-numeric-value lines))
 363     (setq view-scroll-size
 364           (min (if (> lines 0) lines (- lines)) (view-window-size))))
 365   (View-scroll-lines-forward lines))
 366
 367 (defun View-scroll-one-more-line (&optional arg)
 368   "Scroll one more line up in View mode.
 369 With ARG scroll one line down."
 370   (interactive "P")
 371   (View-scroll-lines-forward (if (not arg) 1 -1)))
 372
 373 (defun View-scroll-lines-backward (&optional lines)
 374   "Scroll backward in View mode.
 375 No arg means whole window full, or number of lines set by \\[View-scroll-lines-forward-set-scroll-size].
 376 Arg is number of lines to scroll."
 377   (interactive "P")
 378   (View-scroll-lines-forward (if lines
 379                                  (- (prefix-numeric-value lines))
 380                                (- (view-scroll-size)))))
 381
 382 (defun View-search-regexp-forward (times regexp)
 383   "Search forward for NTH occurrence of REGEXP in View mode.
 384 Displays line found at center of window.  REGEXP is remembered for
 385 searching with \\[View-search-last-regexp-forward] and \\[View-search-last-regexp-backward].  Sets mark at starting position and pushes mark ring."
 386   (interactive "p\nsSearch forward (regexp): ")
 387   (if (> (length regexp) 0)
 388       (progn
 389        ;(view-last-command 'View-search-last-regexp-forward times)
 390         (view-search times regexp))))
 391
 392 (defun View-search-regexp-backward (times regexp)
 393   "Search backward from window start for NTH instance of REGEXP in View mode.
 394 Displays line found at center of window.  REGEXP is remembered for
 395 searching with \\[View-search-last-regexp-forward] and \\[View-search-last-regexp-backward].  Sets mark at starting position and pushes mark ring."
 396   (interactive "p\nsSearch backward (regexp): ")
 397   (View-search-regexp-forward (- times) regexp))
 398
 399 (defun View-search-last-regexp-forward (times)
 400   "Search forward from window end for NTH instance of last regexp in View mode.
 401 Displays line found at center of window.  Sets mark at starting position
 402 and pushes mark ring."
 403   (interactive "p")
 404   (View-search-regexp-forward times view-last-regexp))
 405
 406 (defun View-search-last-regexp-backward (times)
 407   "Search backward from window start for NTH instance of last regexp in View mode.
 408 Displays line found at center of window.  Sets mark at starting position and
 409 pushes mark ring."
 410   (interactive "p")
 411   (View-search-regexp-backward times view-last-regexp))
 412
 413 (defun View-back-to-mark (&optional ignore)
 414   "Return to last mark set in View mode, else beginning of file.
 415 Displays line at center of window.  Pops mark ring so successive
 416 invocations return to earlier marks."
 417   (interactive)
 418   (goto-char (or (mark) (point-min)))
 419   (pop-mark)
 420   (recenter (/ (view-window-size) 2)))
 421
 422 (defun view-search (times regexp)
 423   (setq view-last-regexp regexp)
 424   (let (where)
 425     (save-excursion
 426       (move-to-window-line (if (< times 0) 0 -1))
 427       (if (re-search-forward regexp nil t times)
 428           (setq where (point))))
 429     (if where
 430         (progn
 431           (push-mark)
 432           (goto-char where)
 433           (beginning-of-line)
 434           (recenter (/ (view-window-size) 2)))
 435       (message "Can't find occurrence %d of %s" times regexp)
 436       (sit-for 4))))
 437
 438 \f
 439 (provide 'view)
 440
 441 ;;; view.el ends here