1 ;;; view.el --- peruse file or buffer without editing.
3 ;; Copyright (C) 1985, 1989, 1994, 1995 Free Software Foundation, Inc.
5 ;; Author: K. Shane Hartman
8 ;; This file is part of GNU Emacs.
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)
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.
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.
26 ;; This package provides the `view' minor mode documented in the Emacs
32 (defvar view-highlight-face
'highlight
33 "*The overlay face used for highlighting the match found by View mode search.")
35 (defvar view-mode nil
"Non-nil if View mode is enabled.")
36 (make-variable-buffer-local 'view-mode
)
38 (defvar view-mode-auto-exit nil
39 "Non-nil means scrolling past the end of buffer exits View mode.")
40 (make-variable-buffer-local 'view-mode-auto-exit
)
42 (defvar view-old-buffer-read-only nil
)
43 (make-variable-buffer-local 'view-old-buffer-read-only
)
44 (defvar view-old-Helper-return-blurb
)
45 (make-variable-buffer-local 'view-old-Helper-return-blurb
)
47 (defvar view-scroll-size nil
)
48 (make-variable-buffer-local 'view-scroll-size
)
50 (defvar view-last-regexp nil
)
51 (make-variable-buffer-local 'view-last-regexp
)
53 (defvar view-exit-action nil
)
54 (make-variable-buffer-local 'view-exit-action
)
55 (defvar view-return-here nil
)
56 (make-variable-buffer-local 'view-return-here
)
57 (defvar view-exit-position nil
)
58 (make-variable-buffer-local 'view-exit-position
)
60 (defvar view-overlay nil
61 "Overlay used to display where a search operation found its match.
62 This is local in each buffer, once it is used.")
63 (make-variable-buffer-local 'view-overlay
)
65 (or (assq 'view-mode minor-mode-alist
)
66 (setq minor-mode-alist
67 (cons '(view-mode " View") minor-mode-alist
)))
69 (defvar view-mode-map nil
)
72 (setq view-mode-map
(make-keymap))
73 (suppress-keymap view-mode-map
)
74 (define-key view-mode-map
"q" 'view-exit
)
75 (define-key view-mode-map
"<" 'beginning-of-buffer
)
76 (define-key view-mode-map
">" 'end-of-buffer
)
77 (define-key view-mode-map
"\ev" 'View-scroll-lines-backward
)
78 (define-key view-mode-map
"\C-v" 'View-scroll-lines-forward
)
79 (define-key view-mode-map
" " 'View-scroll-lines-forward
)
80 (define-key view-mode-map
"\C-?" 'View-scroll-lines-backward
)
81 (define-key view-mode-map
"\n" 'View-scroll-one-more-line
)
82 (define-key view-mode-map
"\r" 'View-scroll-one-more-line
)
83 (define-key view-mode-map
"z" 'View-scroll-lines-forward-set-scroll-size
)
84 (define-key view-mode-map
"g" 'View-goto-line
)
85 (define-key view-mode-map
"=" 'what-line
)
86 (define-key view-mode-map
"." 'set-mark-command
)
87 (define-key view-mode-map
"'" 'View-back-to-mark
)
88 (define-key view-mode-map
"@" 'View-back-to-mark
)
89 (define-key view-mode-map
"x" 'exchange-point-and-mark
)
90 (define-key view-mode-map
"h" 'Helper-describe-bindings
)
91 (define-key view-mode-map
"?" 'Helper-describe-bindings
)
92 (define-key view-mode-map
(char-to-string help-char
) 'Helper-help
)
93 (define-key view-mode-map
"s" 'isearch-forward
)
94 (define-key view-mode-map
"r" 'isearch-backward
)
95 (define-key view-mode-map
"/" 'View-search-regexp-forward
)
96 (define-key view-mode-map
"\\" 'View-search-regexp-backward
)
97 ;; This conflicts with the standard binding of isearch-regexp-forward
98 (define-key view-mode-map
"\e\C-s" 'View-search-regexp-forward
)
99 (define-key view-mode-map
"\e\C-r" 'View-search-regexp-backward
)
100 (define-key view-mode-map
"n" 'View-search-last-regexp-forward
)
101 (define-key view-mode-map
"p" 'View-search-last-regexp-backward
)
104 (or (assq 'view-mode minor-mode-map-alist
)
105 (setq minor-mode-map-alist
106 (cons (cons 'view-mode view-mode-map
) minor-mode-map-alist
)))
110 (defun view-file (file-name)
111 "View FILE in View mode, returning to previous buffer when done.
112 The usual Emacs commands are not available; instead,
113 a special set of commands (mostly letters and punctuation)
114 are defined for moving around in the buffer.
115 Space scrolls forward, Delete scrolls backward.
116 For list of all View commands, type ? or h while viewing.
118 This command runs the normal hook `view-mode-hook'."
119 (interactive "fView file: ")
120 (let ((old-buf (current-buffer))
121 (had-a-buf (get-file-buffer file-name
))
122 (buf-to-view (find-file-noselect file-name
)))
123 ;; This used to pass t as second argument,
124 ;; but then the buffer did not show up in the Buffers menu.
125 (switch-to-buffer buf-to-view had-a-buf
)
126 (view-mode-enter old-buf
127 (and (not had-a-buf
) (not (buffer-modified-p buf-to-view
))
131 (defun view-file-other-window (file-name)
132 "View FILE in View mode in other window.
133 Return to previous buffer when done.
134 The usual Emacs commands are not available; instead,
135 a special set of commands (mostly letters and punctuation)
136 are defined for moving around in the buffer.
137 Space scrolls forward, Delete scrolls backward.
138 For list of all View commands, type ? or h while viewing.
140 This command runs the normal hook `view-mode-hook'."
141 (interactive "fView file: ")
142 (let ((old-arrangement (current-window-configuration))
143 (had-a-buf (get-file-buffer file-name
))
144 (buf-to-view (find-file-noselect file-name
)))
145 (switch-to-buffer-other-window buf-to-view
)
146 (view-mode-enter old-arrangement
147 (and (not had-a-buf
) (not (buffer-modified-p buf-to-view
))
151 (defun view-buffer (buffer-name)
152 "View BUFFER in View mode, returning to previous buffer when done.
153 The usual Emacs commands are not available; instead,
154 a special set of commands (mostly letters and punctuation)
155 are defined for moving around in the buffer.
156 Space scrolls forward, Delete scrolls backward.
157 For list of all View commands, type ? or h while viewing.
159 This command runs the normal hook `view-mode-hook'."
160 (interactive "bView buffer: ")
161 (let ((old-buf (current-buffer)))
162 (switch-to-buffer buffer-name t
)
163 (view-mode-enter old-buf nil
)))
166 (defun view-buffer-other-window (buffer-name not-return
)
167 "View BUFFER in View mode in another window.
168 Return to previous buffer when done, unless NOT-RETURN is non-nil.
170 The usual Emacs commands are not available in View mode; instead,
171 a special set of commands (mostly letters and punctuation)
172 are defined for moving around in the buffer.
173 Space scrolls forward, Delete scrolls backward.
174 For list of all View commands, type ? or h while viewing.
176 This command runs the normal hook `view-mode-hook'."
177 (interactive "bView buffer:\nP")
178 (let ((return-to (and not-return
(current-window-configuration))))
179 (switch-to-buffer-other-window buffer-name
)
180 (view-mode-enter return-to
)))
183 (defun view-mode (&optional arg
)
185 If you use this function to turn on View mode,
186 \"exiting\" View mode does nothing except turn View mode off.
187 The other way to turn View mode on is by calling
193 (> (prefix-numeric-value arg
) 0)))
194 (force-mode-line-update))
196 (defun view-mode-enter (&optional prev-buffer action
)
197 "Minor mode for viewing text but not editing it.
198 Letters do not insert themselves. Instead these commands are provided.
199 Most commands take prefix arguments. Commands dealing with lines
200 default to \"scroll size\" lines (initially size of window).
201 Search commands default to a repeat count of one.
202 M-< or < move to beginning of buffer.
203 M-> or > move to end of buffer.
204 C-v or Space scroll forward lines.
205 M-v or DEL scroll backward lines.
206 CR or LF scroll forward one line (backward with prefix argument).
207 z like Space except set number of lines for further
208 scrolling commands to scroll by.
209 C-u and Digits provide prefix arguments. `-' denotes negative argument.
210 = prints the current line number.
211 g goes to line given by prefix argument.
212 / or M-C-s searches forward for regular expression
213 \\ or M-C-r searches backward for regular expression.
214 n searches forward for last regular expression.
215 p searches backward for last regular expression.
216 C-@ or . set the mark.
217 x exchanges point and mark.
218 C-s or s do forward incremental search.
219 C-r or r do reverse incremental search.
220 @ or ' return to mark and pops mark ring.
221 Mark ring is pushed at start of every
222 successful search and when jump to line to occurs.
223 The mark is set on jump to buffer start or end.
224 ? or h provide help message (list of commands).
225 \\[Helper-help] provides help (list of commands or description of a command).
226 C-n moves down lines vertically.
227 C-p moves upward lines vertically.
228 C-l recenters the screen.
229 q exit view-mode and return to previous buffer.
231 This function runs the normal hook `view-mode-hook'.
234 ; Not interactive because dangerous things happen
235 ; if you call it without passing a buffer as argument
236 ; and they are not easy to fix.
238 (setq view-old-buffer-read-only buffer-read-only
)
239 (setq view-old-Helper-return-blurb
240 (and (boundp 'Helper-return-blurb
) Helper-return-blurb
))
242 ;; Enable view-exit to make use of the data we just saved
243 ;; and to perform the exit action.
244 (setq view-mode-auto-exit t
)
246 (setq buffer-read-only t
)
248 (setq Helper-return-blurb
249 (format "continue viewing %s"
250 (if (buffer-file-name)
251 (file-name-nondirectory (buffer-file-name))
254 (setq view-exit-action action
)
255 (setq view-return-here prev-buffer
)
256 (setq view-exit-position
(point-marker))
259 (setq goal-column nil
)
261 (run-hooks 'view-mode-hook
)
263 (substitute-command-keys
264 "Type \\[Helper-help] for help, \\[Helper-describe-bindings] for commands, \\[view-exit] to quit.")))
267 "Exit from view-mode.
268 If you viewed an existing buffer, that buffer returns to its previous mode.
269 If you viewed a file that was not present in Emacs, its buffer is killed."
272 (and view-overlay
(delete-overlay view-overlay
))
273 (force-mode-line-update)
274 (cond (view-mode-auto-exit
275 (setq buffer-read-only view-old-buffer-read-only
)
276 (setq view-mode-auto-exit nil
)
278 (goto-char view-exit-position
)
279 (set-marker view-exit-position nil
)
281 ;; Now do something to the buffer that we were viewing
282 ;; (such as kill it).
283 (let ((viewed-buffer (current-buffer))
284 (action view-exit-action
))
286 ((bufferp view-return-here
)
287 (switch-to-buffer view-return-here
))
288 ((window-configuration-p view-return-here
)
289 (set-window-configuration view-return-here
)))
290 (if action
(funcall action viewed-buffer
))))))
292 (defun view-window-size () (1- (window-height)))
294 (defun view-scroll-size ()
295 (min (view-window-size) (or view-scroll-size
(view-window-size))))
297 (defvar view-mode-hook nil
298 "Normal hook run when starting to view a buffer or file.")
300 ;(defun view-last-command (&optional who what)
301 ; (setq view-last-command-entry this-command)
302 ; (setq view-last-command who)
303 ; (setq view-last-command-argument what))
305 ;(defun View-repeat-last-command ()
306 ; "Repeat last command issued in View mode."
308 ; (if (and view-last-command
309 ; (eq view-last-command-entry last-command))
310 ; (funcall view-last-command view-last-command-argument))
311 ; (setq this-command view-last-command-entry))
313 (defun View-goto-line (line)
314 "Move to line LINE in View mode.
315 Display is centered at LINE. Sets mark at starting position and pushes
320 (recenter (/ (view-window-size) 2)))
322 (defun View-scroll-lines-forward (&optional lines
)
323 "Scroll forward in View mode, or exit if end of text is visible.
324 No arg means whole window full, or number of lines set by \\[View-scroll-lines-forward-set-scroll-size].
325 Arg is number of lines to scroll."
328 (if lines
(prefix-numeric-value lines
)
330 (if (and (pos-visible-in-window-p (point-max))
331 ;; Allow scrolling backward at the end of the buffer.
335 ;; (view-last-command 'View-scroll-lines-forward lines)
336 (if (>= lines
(view-window-size))
338 (if (>= (- lines
) (view-window-size))
341 (cond ((pos-visible-in-window-p (point-max))
342 (goto-char (point-max))
344 (message (substitute-command-keys
345 "End. Type \\[view-exit] to quit viewing."))))
346 (move-to-window-line -
1)
347 (beginning-of-line)))
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."
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
))
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."
368 (View-scroll-lines-forward (if (not arg
) 1 -
1)))
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."
375 (View-scroll-lines-forward (if lines
376 (- (prefix-numeric-value lines
))
377 (- (view-scroll-size)))))
379 (defun View-search-regexp-forward (n regexp
)
380 "Search forward for Nth occurrence of REGEXP.
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.
384 The variable `view-highlight-face' controls the face that is used
385 for highlighting the match that is found."
386 (interactive "p\nsSearch forward (regexp): ")
387 ;;;(view-last-command 'View-search-last-regexp-forward n)
388 (view-search n
(if (equal regexp
"") view-last-regexp regexp
)))
390 (defun View-search-regexp-backward (n regexp
)
391 "Search backward from window start for Nth instance of REGEXP.
392 Displays line found at center of window. REGEXP is remembered for
393 searching with \\[View-search-last-regexp-forward] and \\[View-search-last-regexp-backward]. Sets mark at starting position and pushes mark ring.
395 The variable `view-highlight-face' controls the face that is used
396 for highlighting the match that is found."
397 (interactive "p\nsSearch backward (regexp): ")
398 (View-search-regexp-forward (- n
)
399 (if (equal regexp
"") view-last-regexp regexp
)))
401 (defun View-search-last-regexp-forward (n)
402 "Search forward from window end for Nth instance of last regexp.
403 Displays line found at center of window. Sets mark at starting position
404 and pushes mark ring.
406 The variable `view-highlight-face' controls the face that is used
407 for highlighting the match that is found."
409 (View-search-regexp-forward n view-last-regexp
))
411 (defun View-search-last-regexp-backward (n)
412 "Search backward from window start for Nth instance of last regexp.
413 Displays line found at center of window. Sets mark at starting position and
416 The variable `view-highlight-face' controls the face that is used
417 for highlighting the match that is found."
419 (View-search-regexp-backward n view-last-regexp
))
421 (defun View-back-to-mark (&optional ignore
)
422 "Return to last mark set in View mode, else beginning of file.
423 Displays line at center of window. Pops mark ring so successive
424 invocations return to earlier marks."
426 (goto-char (or (mark t
) (point-min)))
428 (recenter (/ (view-window-size) 2)))
430 (defun view-search (times regexp
)
431 (setq view-last-regexp regexp
)
434 (move-to-window-line (if (< times
0) 0 -
1))
435 (if (re-search-forward regexp nil t times
)
436 (setq where
(point))))
442 (move-overlay view-overlay
(match-beginning 0) (match-end 0))
444 (make-overlay (match-beginning 0) (match-end 0))))
445 (overlay-put view-overlay
'face view-highlight-face
)
447 (recenter (/ (view-window-size) 2)))
448 (message "Can't find occurrence %d of %s" times regexp
)
454 ;;; view.el ends here