comparison lisp/modes/view-less.el @ 0:376386a54a3c r19-14

Import from CVS: tag r19-14
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date Mon, 13 Aug 2007 08:45:50 +0200
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1 ;;; view-less.el --- Minor mode for browsing files with keybindings like `less'
2
3 ;; Copyright (C) 1994, 1995 Tinker Systems and INS Engineering Corp.
4
5 ;; Author: Jonathan Stigelman
6 ;; Keywords: wp unix
7
8 ;; This file is part of XEmacs.
9 ;;
10 ;; XEmacs 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 of the License, or
13 ;; (at your option) any later version.
14 ;;
15 ;; XEmacs 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 XEmacs; if not, write to the Free Software
22 ;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23
24 ;;; Synched up with: Not in FSF.
25
26 ;;; Commentary:
27
28 ;; This mode is for browsing files without changing them. Keybindings
29 ;; similar to those used by the less(1) program are used.
30 ;;
31 ;; Originally written for v18 by David Gudeman (gudeman@arizona.edu)
32 ;; Mods by Bengt Martensson, to closely resemble less (July 1987)
33 ;;
34 ;; If you would like all write-protected files to be visited in view-mode,
35 ;; then add the following to your .emacs file:
36 ;;
37 ;; (add-hook 'find-file-hooks 'auto-view-mode)
38
39 ;;; Code:
40
41 (defvar view-search-string ""
42 "Last string searched for with view-search functions.")
43
44 (defvar view-search-arg 1
45 "Argument to last view search.")
46
47 (defvar view-default-lines 10
48 "Default value for the \"d\" and \"u\" commands in view-mode")
49
50 (defvar view-minor-mode nil
51 "Non-nil when view-mode is active. Call `view-mode' to toggle.")
52 (make-variable-buffer-local 'view-minor-mode)
53
54 (defvar view-minor-mode-map
55 (let ((map (make-keymap)))
56 (set-keymap-name map 'view-minor-mode-map)
57 (suppress-keymap map)
58 (define-key map "-" 'negative-argument)
59 (define-key map " " 'scroll-up)
60 (define-key map "f" 'scroll-up)
61 (define-key map "\177" 'scroll-down)
62 (define-key map "b" 'scroll-down)
63 (define-key map 'backspace 'scroll-down)
64 (define-key map "\r" 'view-scroll-lines-up)
65 (define-key map "\n" 'view-scroll-lines-up)
66 (define-key map "e" 'view-scroll-lines-up)
67 (define-key map "j" 'view-scroll-lines-up)
68 (define-key map "y" 'view-scroll-lines-down)
69 (define-key map "k" 'view-scroll-lines-down)
70 (define-key map "d" 'view-scroll-some-lines-up)
71 (define-key map "u" 'view-scroll-some-lines-down)
72 (define-key map "r" 'recenter)
73 (define-key map "t" 'toggle-truncate-lines)
74 (define-key map "N" 'view-buffer)
75 (define-key map "E" 'view-file)
76 (define-key map "P" 'view-buffer)
77 (define-key map "!" 'shell-command)
78 (define-key map "|" 'shell-command-on-region)
79 (define-key map "=" 'what-line)
80 (define-key map "?" 'view-search-backward)
81 (define-key map "h" 'view-mode-describe)
82 (define-key map "s" 'view-repeat-search)
83 (define-key map "n" 'view-repeat-search)
84 (define-key map "/" 'view-search-forward)
85 (define-key map "\\" 'view-search-backward)
86 (define-key map "g" 'view-goto-line)
87 (define-key map "G" 'view-last-windowful)
88 (define-key map "%" 'view-goto-percent)
89 (define-key map "p" 'view-goto-percent)
90 (define-key map "m" 'point-to-register)
91 (define-key map "'" 'register-to-point)
92 (define-key map "C" 'view-cleanup-backspaces)
93 (define-key map "\C-c\C-c" 'view-quit)
94 ;; #### - should this use substitute-command-keys?
95 (define-key map "\C-x\C-q" 'view-quit-toggle-ro)
96 (define-key map "q" 'view-quit)
97 map
98 ))
99
100 (add-minor-mode 'view-minor-mode " View" view-minor-mode-map)
101
102 (defvar view-mode-map
103 (let ((map (copy-keymap view-minor-mode-map)))
104 (set-keymap-name map 'view-mode-map)
105 map))
106
107 ;;;###autoload
108 (defun view-file (file &optional other-p)
109 "Find FILE, enter view mode. With prefix arg OTHER-P, use other window."
110 (interactive "fView File: \nP")
111 (let ((old-p (get-file-buffer file))
112 (obuf (current-buffer)))
113 (if other-p
114 (find-file-other-window file)
115 (find-file file))
116 (view-mode (if other-p nil obuf)
117 (if old-p nil 'kill-buffer))
118 nil))
119
120 ;;;###autoload
121 (defun view-buffer (buf &optional other-p)
122 "Switch to BUF, enter view mode. With prefix arg use other window."
123 (interactive "bView Buffer: \nP")
124 (let ((obuf (current-buffer)))
125 (if other-p
126 (switch-to-buffer-other-window buf)
127 (switch-to-buffer buf))
128 (view-mode (if other-p nil obuf) (if other-p nil 'bury-buffer))))
129
130 ;;;###autoload
131 (defun view-file-other-window (file)
132 "Find FILE in other window, and enter view mode."
133 (interactive "fView File: ")
134 (view-file file t))
135
136 ;;;###autoload
137 (defun view-buffer-other-window (buffer)
138 "Switch to BUFFER in another window, and enter view mode."
139 (interactive "bView Buffer: ")
140 (view-buffer buffer t))
141
142 (defun view-brief-help ()
143 (message
144 (substitute-command-keys
145 "\\<view-minor-mode-map>\\[scroll-up] = page forward; \\[scroll-down] = page back; \
146 \\[view-mode-describe] = help; \\[view-quit] = quit.")))
147
148 (defvar view-exit-position)
149 (defvar view-prev-buffer)
150 (defvar view-exit-action)
151 (defvar view-old-buffer-read-only)
152
153 ;;;###autoload
154 (defun view-minor-mode (&optional prev-buffer exit-action)
155 "Minor mode for viewing text, with bindings like `less'.
156 Commands are:
157 \\<view-minor-mode-map>
158 0..9 prefix args
159 - prefix minus
160 \\[scroll-up] page forward
161 \\[scroll-down] page back
162 \\[view-scroll-lines-up] scroll prefix-arg lines forward, default 1.
163 \\[view-scroll-lines-down] scroll prefix-arg lines backward, default 1.
164 \\[view-scroll-some-lines-down] scroll prefix-arg lines backward, default 10.
165 \\[view-scroll-some-lines-up] scroll prefix-arg lines forward, default 10.
166 \\[what-line] print line number
167 \\[view-mode-describe] print this help message
168 \\[view-search-forward] regexp search, uses previous string if you just hit RET
169 \\[view-search-backward] as above but searches backward
170 \\[view-repeat-search] repeat last search
171 \\[view-goto-line] goto line prefix-arg, default 1
172 \\[view-last-windowful] goto line prefix-arg, default last line
173 \\[view-goto-percent] goto a position by percentage
174 \\[toggle-truncate-lines] toggle truncate-lines
175 \\[view-file] view another file
176 \\[view-buffer] view another buffer
177 \\[view-cleanup-backspaces] cleanup backspace constructions
178 \\[shell-command] execute a shell command
179 \\[shell-command-on-region]\
180 execute a shell command with the region as input
181 \\[view-quit] exit view-mode, and bury the current buffer.
182
183 If invoked with the optional (prefix) arg non-nil, view-mode cleans up
184 backspace constructions.
185
186 More precisely:
187 \\{view-minor-mode-map}"
188 (interactive)
189
190 (make-local-variable 'view-default-lines)
191 (set (make-local-variable 'view-exit-position) (point))
192 (set (make-local-variable 'view-prev-buffer) prev-buffer)
193 (set (make-local-variable 'view-exit-action) exit-action)
194 (set (make-local-variable 'view-old-buffer-read-only) buffer-read-only)
195 (add-hook (make-local-variable 'change-major-mode-hook)
196 'view-fixup-read-only)
197 (setq view-minor-mode t
198 buffer-read-only t)
199 (view-brief-help))
200
201 ;;;###autoload
202 (defun view-mode (&optional prev-buffer exit-action clean-bs)
203 "View the current buffer using view-minor-mode. This exists to be 99.9%
204 compatible with the implementations of `view-mode' in view.el and older
205 versions of view-less.el."
206 (interactive (list nil 'bury-buffer current-prefix-arg))
207 ;; #### - The first two arguments provide compatibility with view.el (and
208 ;; thus FSFmacs), while the third argument as a prefix argument maintains
209 ;; interactive compatibility with older versions of view-less. --Stig
210 (if clean-bs (cleanup-backspaces))
211 (view-minor-mode prev-buffer exit-action))
212
213 ;;;###autoload
214 (defun view-major-mode (&optional prev-buffer exit-action clean-bs)
215 "View the current buffer using view-mode, as a major mode.
216 This function has a nonstandard name because `view-mode' is wrongly
217 named but is like this for compatibility reasons."
218 ;; #### - The first two arguments provide compatibility with view.el (and
219 ;; thus FSFmacs), while the third argument as a prefix argument maintains
220 ;; interactive compatibility with older versions of view-less. --Stig
221 (interactive (list nil 'bury-buffer current-prefix-arg))
222 (kill-all-local-variables)
223 (use-local-map view-mode-map)
224 (setq major-mode 'view-mode)
225 (set (make-local-variable 'view-exit-position) (point))
226 (set (make-local-variable 'view-prev-buffer) prev-buffer)
227 (set (make-local-variable 'view-exit-action) exit-action)
228 (set (make-local-variable 'view-old-buffer-read-only) buffer-read-only)
229 (set (make-local-variable 'view-major-mode) t)
230 (setq buffer-read-only t)
231 (if clean-bs (cleanup-backspaces))
232 (run-hooks 'view-mode-hook))
233
234 ;;;###autoload
235 (defun auto-view-mode ()
236 "If the file of the current buffer is not writable, call view-mode.
237 This is meant to be added to `find-file-hooks'."
238 (or (file-writable-p buffer-file-name)
239 (view-minor-mode)))
240
241 (defun view-fixup-read-only ()
242 ;; doing M-x normal mode should NOT leave the buffer read-only
243 (and (boundp 'view-old-buffer-read-only)
244 (progn (setq buffer-read-only view-old-buffer-read-only)
245 (kill-local-variable 'view-old-buffer-read-only))))
246
247 (defun view-quit-toggle-ro ()
248 "Exit view mode and execute the global binding of the key that invoked this
249 command. Normally, this will toggle the state of `buffer-read-only', perhaps
250 invoking some version-control mechanism."
251 (interactive)
252 (setq view-exit-position nil)
253 ;; Kludge so this works as advertised. Stig, why can't you write
254 ;; bug-free code???
255 (let ((buffer-read-only buffer-read-only))
256 (view-quit t))
257 ;; no longer in view-minor-mode, so the keymap has changed...
258 (call-interactively (key-binding (this-command-keys))))
259
260 (defun view-quit (&optional no-exit-action)
261 "Exit view mode. With prefix argument, keep the current buffer selected."
262 (interactive "P")
263 (view-fixup-read-only)
264 (setq view-minor-mode nil)
265 (if view-exit-position (goto-char view-exit-position))
266 (if (and (boundp 'view-major-mode) view-major-mode)
267 (fundamental-mode)
268 (let ((pbuf view-prev-buffer)
269 (exitact view-exit-action))
270 (if no-exit-action
271 nil
272 (if exitact (funcall exitact (current-buffer)))
273 (if pbuf (switch-to-buffer pbuf))))))
274
275 ;; #### - similar to what's in man.el and this ought to be written in C anyway... --Stig
276 (defun cleanup-backspaces ()
277 "Cleanup backspace constructions.
278 _^H and ^H_ sequences are deleted. x^Hx sequences are turned into x for all
279 characters x. ^^H| and |^H^ sequences are turned into ^. +^Ho and o^H+ are
280 turned into (+)."
281 (interactive)
282 (save-excursion
283 (goto-char (point-min))
284 (while (= (following-char) ?\C-h)
285 (delete-char 1))
286 (while (search-forward "\C-h" nil t)
287 (forward-char -2)
288 (cond ((looking-at "_\C-h\\|\\(.\\)\C-h\\1\\||\C-h\\^")
289 (delete-char 2))
290 ((looking-at ".\C-h_\\|\\^\C-h|")
291 (forward-char 1)
292 (delete-char 2))
293 ((looking-at "+\C-ho\\|o\C-h+")
294 (delete-char 3)
295 (insert "(+)"))
296 ((looking-at "|\C-h-")
297 (delete-char 3)
298 (insert "*"))
299 (t (forward-char 2))))))
300
301 (defun view-cleanup-backspaces ()
302 "Cleanup backspaces and if buffer is currently unmodified, don't flag it
303 as a modified buffer. This works even if the buffer is read-only."
304 (interactive)
305 (let ((buffer-read-only)
306 (buf-mod (buffer-modified-p)))
307 (cleanup-backspaces)
308 ;; #### - THIS IS PROBABLY A REALLY DANGEROUS THING TO DO IN A MINOR MODE!!
309 (set-buffer-modified-p buf-mod)))
310
311 (defun toggle-truncate-lines (&optional p)
312 "Toggles the values of truncate-lines.
313 Positive prefix arg sets, negative disables."
314 (interactive "P")
315 (setq truncate-lines (if p
316 (> (prefix-numeric-value p) 0)
317 (not truncate-lines)))
318 (recenter))
319
320 (defun view-scroll-lines-up (p)
321 "Scroll up prefix-arg lines, default 1."
322 (interactive "p")
323 (scroll-up p))
324
325 (defun view-scroll-lines-down (p)
326 "Scroll down prefix-arg lines, default 1."
327 (interactive "p")
328 (scroll-up (- p)))
329
330 (defun view-scroll-some-lines-down (&optional n)
331 "Scroll down prefix-arg lines, default 10, or last argument."
332 (interactive "p")
333 (if (> n 1) (setq view-default-lines n))
334 (scroll-down view-default-lines))
335
336 (defun view-scroll-some-lines-up (&optional n)
337 "Scroll up prefix-arg lines, default 10, or last argument."
338 (interactive "p")
339 (if (> n 1) (setq view-default-lines n))
340 (scroll-up view-default-lines))
341
342 (defun view-goto-line (&optional n)
343 "Goto prefix arg line N. N = 1 by default.."
344 (interactive "p")
345 (goto-line n))
346
347 (defun view-last-windowful (&optional n)
348 "Goto prefix arg line N or the first line of the last windowful in buffer."
349 (interactive "p")
350 (if current-prefix-arg
351 (goto-line n)
352 (end-of-buffer)
353 (recenter -1)
354 (move-to-window-line 0)))
355
356 (defun view-goto-percent (&optional percent)
357 "Set mark and go to a position PERCENT way into the current buffer."
358 (interactive "p")
359 (set-mark-command nil)
360 (goto-char (+ (point-min) (/ (* percent (- (point-max) (point-min))) 100)))
361 (beginning-of-line))
362
363 (defun view-mode-describe ()
364 (interactive)
365 (let ((mode-name "View")
366 (major-mode 'view-mode))
367 (describe-mode)))
368
369 (defun view-search-forward (s p)
370 "Search forward for REGEXP. If regexp is empty, use last search string.
371 With prefix ARG, search forward that many occurrences."
372 (interactive "sView search: \np")
373 (unwind-protect
374 (re-search-forward
375 (if (string-equal "" s) view-search-string s) nil nil p)
376 (setq view-search-arg p)
377 (or (string-equal "" s)
378 (setq view-search-string s))))
379
380 (defun view-search-backward (s p)
381 "Search backward for REGEXP. If regexp is empty, use last search string.
382 With prefix ARG, search forward that many occurrences."
383 (interactive "sView search backward: \np")
384 (view-search-forward s (- p)))
385
386 (defun view-repeat-search (p)
387 "Repeat last view search command. If a prefix arg is given, use that
388 instead of the previous arg, if the prefix is just a -, then take the
389 negative of the last prefix arg."
390 (interactive "P")
391 (view-search-forward
392 view-search-string
393 (cond ((null p) view-search-arg)
394 ((eq p '-) (- view-search-arg))
395 (t (prefix-numeric-value p)))))
396
397 (provide 'view)
398 (provide 'view-less)