lisp/view.el

   1 ;; View: Peruse file or buffer without editing.
   2 ;; Copyright (C) 1985, 1989 Free Software Foundation, Inc.
   3 ;; Principal author K. Shane Hartman
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 1, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21
  22 (provide 'view)
  23
  24 (defvar view-mode-map nil)
  25 (if view-mode-map
  26     nil
  27   (setq view-mode-map (make-keymap))
  28   (fillarray (nth 1 view-mode-map) 'View-undefined)
  29   (define-key view-mode-map "\C-c" 'view-exit)
  30   (define-key view-mode-map "\C-z" 'suspend-emacs)
  31   (define-key view-mode-map "q" 'view-exit)
  32   (define-key view-mode-map "-" 'negative-argument)
  33   (define-key view-mode-map "0" 'digit-argument)
  34   (define-key view-mode-map "1" 'digit-argument)
  35   (define-key view-mode-map "2" 'digit-argument)
  36   (define-key view-mode-map "3" 'digit-argument)
  37   (define-key view-mode-map "4" 'digit-argument)
  38   (define-key view-mode-map "5" 'digit-argument)
  39   (define-key view-mode-map "6" 'digit-argument)
  40   (define-key view-mode-map "7" 'digit-argument)
  41   (define-key view-mode-map "8" 'digit-argument)
  42   (define-key view-mode-map "9" 'digit-argument)
  43   (define-key view-mode-map "\C-u" 'universal-argument)
  44   (define-key view-mode-map "\e" nil)
  45   (define-key view-mode-map "\C-x" 'Control-X-prefix)
  46   (define-key view-mode-map "\e-" 'negative-argument)
  47   (define-key view-mode-map "\e0" 'digit-argument)
  48   (define-key view-mode-map "\e1" 'digit-argument)
  49   (define-key view-mode-map "\e2" 'digit-argument)
  50   (define-key view-mode-map "\e3" 'digit-argument)
  51   (define-key view-mode-map "\e4" 'digit-argument)
  52   (define-key view-mode-map "\e5" 'digit-argument)
  53   (define-key view-mode-map "\e6" 'digit-argument)
  54   (define-key view-mode-map "\e7" 'digit-argument)
  55   (define-key view-mode-map "\e8" 'digit-argument)
  56   (define-key view-mode-map "\e9" 'digit-argument)
  57   (define-key view-mode-map "<" 'beginning-of-buffer)
  58   (define-key view-mode-map ">" 'end-of-buffer)
  59   (define-key view-mode-map "\ev" 'View-scroll-lines-backward)
  60   (define-key view-mode-map "\C-v" 'View-scroll-lines-forward)
  61   (define-key view-mode-map " " 'View-scroll-lines-forward)
  62   (define-key view-mode-map "\177" 'View-scroll-lines-backward)
  63   (define-key view-mode-map "\n" 'View-scroll-one-more-line)
  64   (define-key view-mode-map "\r" 'View-scroll-one-more-line)
  65   (define-key view-mode-map "\C-l" 'recenter)
  66   (define-key view-mode-map "z" 'View-scroll-lines-forward-set-scroll-size)
  67   (define-key view-mode-map "g" 'View-goto-line)
  68   (define-key view-mode-map "=" 'what-line)
  69   (define-key view-mode-map "." 'set-mark-command)
  70   (define-key view-mode-map "\C-@" 'set-mark-command)
  71   (define-key view-mode-map "'" 'View-back-to-mark)
  72   (define-key view-mode-map "@" 'View-back-to-mark)
  73   (define-key view-mode-map "x" 'exchange-point-and-mark)
  74   (define-key view-mode-map "h" 'Helper-describe-bindings)
  75   (define-key view-mode-map "?" 'Helper-describe-bindings)
  76   (define-key view-mode-map "\C-h" 'Helper-help)
  77   (define-key view-mode-map "\C-n" 'next-line)
  78   (define-key view-mode-map "\C-p" 'previous-line)
  79   (define-key view-mode-map "\C-s" 'isearch-forward)
  80   (define-key view-mode-map "\C-r" 'isearch-backward)
  81   (define-key view-mode-map "s" 'isearch-forward)
  82   (define-key view-mode-map "r" 'isearch-backward)
  83   (define-key view-mode-map "/" 'View-search-regexp-forward)
  84   (define-key view-mode-map "\\" 'View-search-regexp-backward)
  85   ;; This conflicts with the standard binding of isearch-regexp-forward
  86   (define-key view-mode-map "\e\C-s" 'View-search-regexp-forward)
  87   (define-key view-mode-map "\e\C-r" 'View-search-regexp-backward)
  88   (define-key view-mode-map "n" 'View-search-last-regexp-forward)
  89   (define-key view-mode-map "p" 'View-search-last-regexp-backward)
  90   )
  91
  92
  93 ;;;###autoload
  94 (defun view-file (file-name)
  95   "View FILE in View mode, returning to previous buffer when done.
  96 The usual Emacs commands are not available; instead,
  97 a special set of commands (mostly letters and punctuation)
  98 are defined for moving around in the buffer.
  99 Space scrolls forward, Delete scrolls backward.
 100 For list of all View commands, type ? or h while viewing.
 101
 102 Calls the value of  view-hook  if that is non-nil."
 103   (interactive "fView file: ")
 104   (let ((old-buf (current-buffer))
 105         (had-a-buf (get-file-buffer file-name))
 106         (buf-to-view (find-file-noselect file-name)))
 107     (switch-to-buffer buf-to-view t)
 108     (view-mode old-buf
 109                (and (not had-a-buf) (not (buffer-modified-p buf-to-view))
 110                     'kill-buffer))))
 111
 112 ;;;###autoload
 113 (defun view-file-other-window (file-name)
 114   "View FILE in View mode in other window.
 115 Return to previous buffer when done.
 116 The usual Emacs commands are not available; instead,
 117 a special set of commands (mostly letters and punctuation)
 118 are defined for moving around in the buffer.
 119 Space scrolls forward, Delete scrolls backward.
 120 For list of all View commands, type ? or h while viewing.
 121
 122 Calls the value of  view-hook  if that is non-nil."
 123   (interactive "fView file: ")
 124   (let ((old-arrangement (current-window-configuration))
 125         (had-a-buf (get-file-buffer file-name))
 126         (buf-to-view (find-file-noselect file-name)))
 127     (switch-to-buffer-other-window buf-to-view)
 128     (view-mode old-arrangement
 129                (and (not had-a-buf) (not (buffer-modified-p buf-to-view))
 130                     'kill-buffer))))
 131
 132 ;;;###autoload
 133 (defun view-buffer (buffer-name)
 134   "View BUFFER in View mode, returning to previous buffer when done.
 135 The usual Emacs commands are not available; instead,
 136 a special set of commands (mostly letters and punctuation)
 137 are defined for moving around in the buffer.
 138 Space scrolls forward, Delete scrolls backward.
 139 For list of all View commands, type ? or h while viewing.
 140
 141 Calls the value of  view-hook  if that is non-nil."
 142   (interactive "bView buffer: ")
 143   (let ((old-buf (current-buffer)))
 144     (switch-to-buffer buffer-name t)
 145     (view-mode old-buf nil)))
 146
 147 ;;;###autoload
 148 (defun view-buffer-other-window (buffer-name not-return)
 149   "View BUFFER in View mode in another window,
 150 returning to original buffer when done  ONLY if
 151 prefix argument not-return is nil (as by default).
 152   The usual Emacs commands are not available; instead,
 153 a special set of commands (mostly letters and punctuation)
 154 are defined for moving around in the buffer.
 155 Space scrolls forward, Delete scrolls backward.
 156 For list of all View commands, type ? or h while viewing.
 157
 158 Calls the value of  view-hook  if that is non-nil."
 159   (interactive \"bView buffer:\\nP\")
 160   (let ((return-to (and not-return (current-window-configuration))))
 161     (switch-to-buffer-other-window buffer-name)
 162     (view-mode return-to)))
 163
 164 ;;;###autoload
 165 (defun view-mode (&optional prev-buffer action)
 166   "Major mode for viewing text but not editing it.
 167 Letters do not insert themselves.  Instead these commands are provided.
 168 Most commands take prefix arguments.  Commands dealing with lines
 169 default to \"scroll size\" lines (initially size of window).
 170 Search commands default to a repeat count of one.
 171 M-< or <        move to beginning of buffer.
 172 M-> or >        move to end of buffer.
 173 C-v or Space    scroll forward lines.
 174 M-v or DEL      scroll backward lines.
 175 CR or LF        scroll forward one line (backward with prefix argument).
 176 z               like Space except set number of lines for further
 177                    scrolling commands to scroll by.
 178 C-u and Digits  provide prefix arguments.  `-' denotes negative argument.
 179 =               prints the current line number.
 180 g               goes to line given by prefix argument.
 181 / or M-C-s      searches forward for regular expression
 182 \\ or M-C-r     searches backward for regular expression.
 183 n               searches forward for last regular expression.
 184 p               searches backward for last regular expression.
 185 C-@ or .        set the mark.
 186 x               exchanges point and mark.
 187 C-s or s        do forward incremental search.
 188 C-r or r        do reverse incremental search.
 189 @ or '          return to mark and pops mark ring.
 190                   Mark ring is pushed at start of every
 191                   successful search and when jump to line to occurs.
 192                   The mark is set on jump to buffer start or end.
 193 ? or h          provide help message (list of commands).
 194 C-h             provides help (list of commands or description of a command).
 195 C-n             moves down lines vertically.
 196 C-p             moves upward lines vertically.
 197 C-l             recenters the screen.
 198 q or C-c        exit view-mode and return to previous buffer.
 199
 200 Entry to this mode calls the value of  view-hook  if non-nil.
 201 \\{view-mode-map}"
 202 ;  Not interactive because dangerous things happen
 203 ;  if you call it without passing a buffer as argument
 204 ;  and they are not easy to fix.
 205 ;  (interactive)
 206   (make-local-variable 'view-old-mode-line-buffer-identification)
 207   (setq view-old-mode-line-buffer-identification
 208         mode-line-buffer-identification)
 209   (make-local-variable 'view-old-buffer-read-only)
 210   (setq view-old-buffer-read-only buffer-read-only)
 211   (make-local-variable 'view-old-mode-name)
 212   (setq view-old-mode-name mode-name)
 213   (make-local-variable 'view-old-major-mode)
 214   (setq view-old-major-mode major-mode)
 215   (make-local-variable 'view-old-local-map)
 216   (setq view-old-local-map (current-local-map))
 217   (make-local-variable 'view-old-Helper-return-blurb)
 218   (setq view-old-Helper-return-blurb
 219         (and (boundp 'Helper-return-blurb) Helper-return-blurb))
 220
 221   (setq buffer-read-only t)
 222   (setq mode-line-buffer-identification
 223         (list
 224          (if (buffer-file-name)
 225              "Viewing %f"
 226            "Viewing %b")))
 227   (setq mode-name "View")
 228   (setq major-mode 'view-mode)
 229   (setq Helper-return-blurb
 230         (format "continue viewing %s"
 231                 (if (buffer-file-name)
 232                     (file-name-nondirectory (buffer-file-name))
 233                     (buffer-name))))
 234
 235   (make-local-variable 'view-exit-action)
 236   (setq view-exit-action action)
 237   (make-local-variable 'view-return-here)
 238   (setq view-return-here prev-buffer)
 239   (make-local-variable 'view-exit-position)
 240   (setq view-exit-position (point-marker))
 241
 242   (make-local-variable 'view-scroll-size)
 243   (setq view-scroll-size nil)
 244   (make-local-variable 'view-last-regexp)
 245   (setq view-last-regexp nil)
 246
 247   (beginning-of-line)
 248   (setq goal-column nil)
 249
 250   (use-local-map view-mode-map)
 251   (run-hooks 'view-hook)
 252   (view-helpful-message))
 253
 254 \f
 255 (defun view-exit ()
 256   "Exit from view-mode.
 257 If you viewed an existing buffer, that buffer returns to its previous mode.
 258 If you viewed a file that was not present in Emacs, its buffer is killed."
 259   (interactive)
 260   (setq mode-line-buffer-identification
 261         view-old-mode-line-buffer-identification)
 262   (setq major-mode view-old-major-mode)
 263   (setq mode-name view-old-mode-name)
 264   (use-local-map (current-local-map))
 265   (setq buffer-read-only view-old-buffer-read-only)
 266
 267   (goto-char view-exit-position)
 268   (set-marker view-exit-position nil)
 269
 270   ;; Now do something to the buffer that we were viewing
 271   ;; (such as kill it).
 272   (let ((viewed-buffer (current-buffer))
 273         (action view-exit-action))
 274     (cond
 275      ((bufferp view-return-here)
 276       (switch-to-buffer view-return-here))
 277      ((window-configuration-p view-return-here)
 278       (set-window-configuration view-return-here)))
 279     (if action (funcall action viewed-buffer))))
 280
 281 (defun view-helpful-message ()
 282   (message
 283    (if (and (eq (key-binding "\C-h") 'Helper-help)
 284             (eq (key-binding "?") 'Helper-describe-bindings)
 285             (eq (key-binding "\C-c") 'view-exit))
 286        "Type C-h for help, ? for commands, C-c to quit"
 287      (substitute-command-keys
 288       "Type \\[Helper-help] for help, \\[Helper-describe-bindings] for commands, \\[exit-recursive-edit] to quit."))))
 289
 290 (defun View-undefined ()
 291   (interactive)
 292   (ding)
 293   (view-helpful-message))
 294
 295 (defun view-window-size () (1- (window-height)))
 296
 297 (defun view-scroll-size ()
 298   (min (view-window-size) (or view-scroll-size (view-window-size))))
 299
 300 (defvar view-hook nil
 301   "If non-nil, its value is called when viewing buffer or file.")
 302
 303 ;(defun view-last-command (&optional who what)
 304 ;  (setq view-last-command-entry this-command)
 305 ;  (setq view-last-command who)
 306 ;  (setq view-last-command-argument what))
 307
 308 ;(defun View-repeat-last-command ()
 309 ;  "Repeat last command issued in View mode."
 310 ;  (interactive)
 311 ;  (if (and view-last-command
 312 ;          (eq view-last-command-entry last-command))
 313 ;      (funcall view-last-command view-last-command-argument))
 314 ;  (setq this-command view-last-command-entry))
 315
 316 (defun View-goto-line (&optional line)
 317   "Move to LINE in View mode.
 318 Display is centered at LINE.  Sets mark at starting position and pushes
 319 mark ring."
 320   (interactive "p")
 321   (push-mark)
 322   (goto-line (or line 1))
 323   (recenter (/ (view-window-size) 2)))
 324
 325 (defun View-scroll-lines-forward (&optional lines)
 326   "Scroll forward in View mode, or exit if end of text is visible.
 327 No arg means whole window full, or number of lines set by \\[View-scroll-lines-forward-set-scroll-size].
 328 Arg is number of lines to scroll."
 329   (interactive "P")
 330   (if (pos-visible-in-window-p (point-max))
 331       (exit-recursive-edit))
 332   (setq lines
 333         (if lines (prefix-numeric-value lines)
 334           (view-scroll-size)))
 335 ; (view-last-command 'View-scroll-lines-forward lines)
 336   (if (>= lines (view-window-size))
 337       (scroll-up nil)
 338     (if (>= (- lines) (view-window-size))
 339         (scroll-down nil)
 340       (scroll-up lines)))
 341   (cond ((pos-visible-in-window-p (point-max))
 342          (goto-char (point-max))
 343          (recenter -1)
 344          (message (substitute-command-keys
 345                 "End.  Type \\[exit-recursive-edit] to quit viewing."))))
 346   (move-to-window-line -1)
 347   (beginning-of-line))
 348
 349 (defun View-scroll-lines-forward-set-scroll-size (&optional lines)
 350   "Scroll forward LINES lines in View mode, setting the \"scroll size\".
 351 This is the number of lines which \\[View-scroll-lines-forward] and \\[View-scroll-lines-backward] scroll by default.
 352 The absolute value of LINES is used, so this command can be used to scroll
 353 backwards (but \"scroll size\" is always positive).  If LINES is greater than
 354 window height or omitted, then window height is assumed.  If LINES is less
 355 than window height then scrolling context is provided from previous screen."
 356   (interactive "P")
 357   (if (not lines)
 358       (setq view-scroll-size (view-window-size))
 359     (setq lines (prefix-numeric-value lines))
 360     (setq view-scroll-size
 361           (min (if (> lines 0) lines (- lines)) (view-window-size))))
 362   (View-scroll-lines-forward lines))
 363
 364 (defun View-scroll-one-more-line (&optional arg)
 365   "Scroll one more line up in View mode.
 366 With ARG scroll one line down."
 367   (interactive "P")
 368   (View-scroll-lines-forward (if (not arg) 1 -1)))
 369
 370 (defun View-scroll-lines-backward (&optional lines)
 371   "Scroll backward in View mode.
 372 No arg means whole window full, or number of lines set by \\[View-scroll-lines-forward-set-scroll-size].
 373 Arg is number of lines to scroll."
 374   (interactive "P")
 375   (View-scroll-lines-forward (if lines
 376                                  (- (prefix-numeric-value lines))
 377                                (- (view-scroll-size)))))
 378
 379 (defun View-search-regexp-forward (times regexp)
 380   "Search forward for NTH occurrence of REGEXP in View mode.
 381 Displays line found at center of window.  REGEXP is remembered for
 382 searching with \\[View-search-last-regexp-forward] and \\[View-search-last-regexp-backward].  Sets mark at starting position and pushes mark ring."
 383   (interactive "p\nsSearch forward (regexp): ")
 384   (if (> (length regexp) 0)
 385       (progn
 386        ;(view-last-command 'View-search-last-regexp-forward times)
 387         (view-search times regexp))))
 388
 389 (defun View-search-regexp-backward (times regexp)
 390   "Search backward from window start for NTH instance of REGEXP in View mode.
 391 Displays line found at center of window.  REGEXP is remembered for
 392 searching with \\[View-search-last-regexp-forward] and \\[View-search-last-regexp-backward].  Sets mark at starting position and pushes mark ring."
 393   (interactive "p\nsSearch backward (regexp): ")
 394   (View-search-regexp-forward (- times) regexp))
 395
 396 (defun View-search-last-regexp-forward (times)
 397   "Search forward from window end for NTH instance of last regexp in View mode.
 398 Displays line found at center of window.  Sets mark at starting position
 399 and pushes mark ring."
 400   (interactive "p")
 401   (View-search-regexp-forward times view-last-regexp))
 402
 403 (defun View-search-last-regexp-backward (times)
 404   "Search backward from window start for NTH instance of last regexp in View mode.
 405 Displays line found at center of window.  Sets mark at starting position and
 406 pushes mark ring."
 407   (interactive "p")
 408   (View-search-regexp-backward times view-last-regexp))
 409
 410 (defun View-back-to-mark (&optional ignore)
 411   "Return to last mark set in View mode, else beginning of file.
 412 Displays line at center of window.  Pops mark ring so successive
 413 invocations return to earlier marks."
 414   (interactive)
 415   (goto-char (or (mark) (point-min)))
 416   (pop-mark)
 417   (recenter (/ (view-window-size) 2)))
 418
 419 (defun view-search (times regexp)
 420   (setq view-last-regexp regexp)
 421   (let (where)
 422     (save-excursion
 423       (move-to-window-line (if (< times 0) 0 -1))
 424       (if (re-search-forward regexp nil t times)
 425           (setq where (point))))
 426     (if where
 427         (progn
 428           (push-mark)
 429           (goto-char where)
 430           (beginning-of-line)
 431           (recenter (/ (view-window-size) 2)))
 432       (message "Can't find occurrence %d of %s" times regexp)
 433       (sit-for 4))))
 434
 435 \f
 436 ;;;###autoload
 437 (define-key ctl-x-map "v" 'view-file)
 438
 439 ;;;###autoload
 440 (define-key ctl-x-4-map "v" 'view-file-other-window)