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cf6ffd8c RS |
1 | ;;; longlines.el --- automatically wrap long lines |
2 | ||
aaef169d | 3 | ;; Copyright (C) 2000, 2001, 2004, 2005, 2006 Free Software Foundation, Inc. |
cf6ffd8c RS |
4 | |
5 | ;; Authors: Kai Grossjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE> | |
6 | ;; Alex Schroeder <alex@gnu.org> | |
7 | ;; Chong Yidong <cyd@stupidchicken.com> | |
8 | ;; Maintainer: Chong Yidong <cyd@stupidchicken.com> | |
a145b41c | 9 | ;; Keywords: convenience, wp |
cf6ffd8c RS |
10 | |
11 | ;; This file is part of GNU Emacs. | |
12 | ||
13 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
14 | ;; it under the terms of the GNU General Public License as published by | |
15 | ;; the Free Software Foundation; either version 2, or (at your option) | |
16 | ;; any later version. | |
17 | ||
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
24 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
086add15 LK |
25 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
26 | ;; Boston, MA 02110-1301, USA. | |
cf6ffd8c RS |
27 | |
28 | ;;; Commentary: | |
29 | ||
30 | ;; Some text editors save text files with long lines, and they | |
31 | ;; automatically break these lines at whitespace, without actually | |
32 | ;; inserting any newline characters. When doing `M-q' in Emacs, you | |
33 | ;; are inserting newline characters. Longlines mode provides a file | |
34 | ;; format which wraps the long lines when reading a file and unwraps | |
35 | ;; the lines when saving the file. It can also wrap and unwrap | |
36 | ;; automatically as editing takes place. | |
37 | ||
38 | ;; Special thanks to Rod Smith for many useful bug reports. | |
39 | ||
40 | ;;; Code: | |
41 | ||
cf6ffd8c RS |
42 | (defgroup longlines nil |
43 | "Automatic wrapping of long lines when loading files." | |
44 | :group 'fill) | |
45 | ||
46 | (defcustom longlines-auto-wrap t | |
da95a9c8 | 47 | "Non-nil means long lines are automatically wrapped after each command. |
cf6ffd8c RS |
48 | Otherwise, you can perform filling using `fill-paragraph' or |
49 | `auto-fill-mode'. In any case, the soft newlines will be removed | |
50 | when the file is saved to disk." | |
51 | :group 'longlines | |
52 | :type 'boolean) | |
53 | ||
54 | (defcustom longlines-wrap-follows-window-size nil | |
da95a9c8 | 55 | "Non-nil means wrapping and filling happen at the edge of the window. |
cf6ffd8c RS |
56 | Otherwise, `fill-column' is used, regardless of the window size. This |
57 | does not work well when the buffer is displayed in multiple windows | |
58 | with differing widths." | |
59 | :group 'longlines | |
60 | :type 'boolean) | |
61 | ||
62 | (defcustom longlines-show-hard-newlines nil | |
da95a9c8 | 63 | "Non-nil means each hard newline is marked on the screen. |
c29316d5 | 64 | \(The variable `longlines-show-effect' controls what they look like.) |
cf6ffd8c RS |
65 | You can also enable the display temporarily, using the command |
66 | `longlines-show-hard-newlines'" | |
67 | :group 'longlines | |
68 | :type 'boolean) | |
69 | ||
70 | (defcustom longlines-show-effect (propertize "|\n" 'face 'escape-glyph) | |
da95a9c8 | 71 | "A string to display when showing hard newlines. |
cf6ffd8c RS |
72 | This is used when `longlines-show-hard-newlines' is on." |
73 | :group 'longlines | |
74 | :type 'string) | |
75 | ||
76 | ;; Internal variables | |
77 | ||
78 | (defvar longlines-wrap-beg nil) | |
79 | (defvar longlines-wrap-end nil) | |
80 | (defvar longlines-wrap-point nil) | |
81 | (defvar longlines-showing nil) | |
82 | ||
83 | (make-variable-buffer-local 'longlines-wrap-beg) | |
84 | (make-variable-buffer-local 'longlines-wrap-end) | |
85 | (make-variable-buffer-local 'longlines-wrap-point) | |
86 | (make-variable-buffer-local 'longlines-showing) | |
87 | ||
88 | ;; Mode | |
89 | ||
90 | ;;;###autoload | |
91 | (define-minor-mode longlines-mode | |
92 | "Toggle Long Lines mode. | |
93 | In Long Lines mode, long lines are wrapped if they extend beyond | |
94 | `fill-column'. The soft newlines used for line wrapping will not | |
95 | show up when the text is yanked or saved to disk. | |
96 | ||
c29316d5 | 97 | If the variable `longlines-auto-wrap' is non-nil, lines are automatically |
cf6ffd8c RS |
98 | wrapped whenever the buffer is changed. You can always call |
99 | `fill-paragraph' to fill individual paragraphs. | |
100 | ||
c29316d5 RS |
101 | If the variable `longlines-show-hard-newlines' is non-nil, hard newlines |
102 | are indicated with a symbol." | |
6da6c2fe | 103 | :group 'longlines :lighter " ll" |
cf6ffd8c RS |
104 | (if longlines-mode |
105 | ;; Turn on longlines mode | |
106 | (progn | |
107 | (use-hard-newlines 1 'never) | |
108 | (set (make-local-variable 'require-final-newline) nil) | |
109 | (add-to-list 'buffer-file-format 'longlines) | |
110 | (add-hook 'change-major-mode-hook 'longlines-mode-off nil t) | |
b39aa4fd | 111 | (add-hook 'before-revert-hook 'longlines-before-revert-hook nil t) |
cf6ffd8c | 112 | (make-local-variable 'buffer-substring-filters) |
930aae96 | 113 | (set (make-local-variable 'isearch-search-fun-function) |
7f5bb182 | 114 | 'longlines-search-function) |
cf6ffd8c RS |
115 | (add-to-list 'buffer-substring-filters 'longlines-encode-string) |
116 | (when longlines-wrap-follows-window-size | |
117 | (set (make-local-variable 'fill-column) | |
118 | (- (window-width) window-min-width)) | |
119 | (add-hook 'window-configuration-change-hook | |
120 | 'longlines-window-change-function nil t)) | |
121 | (let ((buffer-undo-list t) | |
6fd388f3 | 122 | (inhibit-read-only t) |
a145b41c | 123 | (after-change-functions nil) |
cf6ffd8c RS |
124 | (mod (buffer-modified-p))) |
125 | ;; Turning off undo is OK since (spaces + newlines) is | |
126 | ;; conserved, except for a corner case in | |
127 | ;; longlines-wrap-lines that we'll never encounter from here | |
e7b382ed CY |
128 | (save-restriction |
129 | (widen) | |
eb0d2864 CY |
130 | (longlines-decode-buffer) |
131 | (longlines-wrap-region (point-min) (point-max))) | |
cf6ffd8c RS |
132 | (set-buffer-modified-p mod)) |
133 | (when (and longlines-show-hard-newlines | |
134 | (not longlines-showing)) | |
135 | (longlines-show-hard-newlines)) | |
0f157ad5 CY |
136 | |
137 | ;; Hacks to make longlines play nice with various modes. | |
138 | (cond ((eq major-mode 'mail-mode) | |
15575807 | 139 | (add-hook 'mail-setup-hook 'longlines-decode-buffer nil t) |
0f157ad5 CY |
140 | (or mail-citation-hook |
141 | (add-hook 'mail-citation-hook 'mail-indent-citation nil t)) | |
142 | (add-hook 'mail-citation-hook 'longlines-decode-region nil t)) | |
143 | ((eq major-mode 'message-mode) | |
2c127d45 | 144 | (add-hook 'message-setup-hook 'longlines-decode-buffer nil t) |
0f157ad5 CY |
145 | (make-local-variable 'message-indent-citation-function) |
146 | (if (not (listp message-indent-citation-function)) | |
147 | (setq message-indent-citation-function | |
148 | (list message-indent-citation-function))) | |
149 | (add-to-list 'message-indent-citation-function | |
150 | 'longlines-decode-region t))) | |
426f8573 CY |
151 | |
152 | (when longlines-auto-wrap | |
153 | (auto-fill-mode 0) | |
154 | (add-hook 'after-change-functions | |
155 | 'longlines-after-change-function nil t) | |
156 | (add-hook 'post-command-hook | |
157 | 'longlines-post-command-function nil t))) | |
cf6ffd8c RS |
158 | ;; Turn off longlines mode |
159 | (setq buffer-file-format (delete 'longlines buffer-file-format)) | |
160 | (if longlines-showing | |
161 | (longlines-unshow-hard-newlines)) | |
6fd388f3 | 162 | (let ((buffer-undo-list t) |
a145b41c | 163 | (after-change-functions nil) |
6fd388f3 | 164 | (inhibit-read-only t)) |
e7b382ed CY |
165 | (save-restriction |
166 | (widen) | |
167 | (longlines-encode-region (point-min) (point-max)))) | |
cf6ffd8c | 168 | (remove-hook 'change-major-mode-hook 'longlines-mode-off t) |
cf6ffd8c RS |
169 | (remove-hook 'after-change-functions 'longlines-after-change-function t) |
170 | (remove-hook 'post-command-hook 'longlines-post-command-function t) | |
b39aa4fd | 171 | (remove-hook 'before-revert-hook 'longlines-before-revert-hook t) |
cf6ffd8c RS |
172 | (remove-hook 'window-configuration-change-hook |
173 | 'longlines-window-change-function t) | |
6fd388f3 CY |
174 | (when longlines-wrap-follows-window-size |
175 | (kill-local-variable 'fill-column)) | |
930aae96 | 176 | (kill-local-variable 'isearch-search-fun-function) |
6fd388f3 CY |
177 | (kill-local-variable 'require-final-newline) |
178 | (kill-local-variable 'buffer-substring-filters) | |
179 | (kill-local-variable 'use-hard-newlines))) | |
cf6ffd8c RS |
180 | |
181 | (defun longlines-mode-off () | |
182 | "Turn off longlines mode. | |
183 | This function exists to be called by `change-major-mode-hook' when the | |
184 | major mode changes." | |
185 | (longlines-mode 0)) | |
186 | ||
187 | ;; Showing the effect of hard newlines in the buffer | |
188 | ||
cf6ffd8c RS |
189 | (defun longlines-show-hard-newlines (&optional arg) |
190 | "Make hard newlines visible by adding a face. | |
191 | With optional argument ARG, make the hard newlines invisible again." | |
192 | (interactive "P") | |
193 | (let ((buffer-undo-list t) | |
194 | (mod (buffer-modified-p))) | |
195 | (if arg | |
196 | (longlines-unshow-hard-newlines) | |
197 | (setq longlines-showing t) | |
198 | (longlines-show-region (point-min) (point-max))) | |
199 | (set-buffer-modified-p mod))) | |
200 | ||
201 | (defun longlines-show-region (beg end) | |
202 | "Make hard newlines between BEG and END visible." | |
203 | (let* ((pmin (min beg end)) | |
204 | (pmax (max beg end)) | |
da95a9c8 SM |
205 | (pos (text-property-not-all pmin pmax 'hard nil)) |
206 | (inhibit-read-only t)) | |
cf6ffd8c RS |
207 | (while pos |
208 | (put-text-property pos (1+ pos) 'display | |
209 | (copy-sequence longlines-show-effect)) | |
52325bee | 210 | (setq pos (text-property-not-all (1+ pos) pmax 'hard nil))))) |
cf6ffd8c RS |
211 | |
212 | (defun longlines-unshow-hard-newlines () | |
213 | "Make hard newlines invisible again." | |
214 | (interactive) | |
215 | (setq longlines-showing nil) | |
52325bee | 216 | (let ((pos (text-property-not-all (point-min) (point-max) 'hard nil))) |
cf6ffd8c RS |
217 | (while pos |
218 | (remove-text-properties pos (1+ pos) '(display)) | |
52325bee | 219 | (setq pos (text-property-not-all (1+ pos) (point-max) 'hard nil))))) |
cf6ffd8c RS |
220 | |
221 | ;; Wrapping the paragraphs. | |
222 | ||
223 | (defun longlines-wrap-region (beg end) | |
224 | "Wrap each successive line, starting with the line before BEG. | |
225 | Stop when we reach lines after END that don't need wrapping, or the | |
226 | end of the buffer." | |
227 | (setq longlines-wrap-point (point)) | |
228 | (goto-char beg) | |
229 | (forward-line -1) | |
230 | ;; Two successful longlines-wrap-line's in a row mean successive | |
231 | ;; lines don't need wrapping. | |
232 | (while (null (and (longlines-wrap-line) | |
233 | (or (eobp) | |
234 | (and (>= (point) end) | |
235 | (longlines-wrap-line)))))) | |
236 | (goto-char longlines-wrap-point)) | |
237 | ||
238 | (defun longlines-wrap-line () | |
239 | "If the current line needs to be wrapped, wrap it and return nil. | |
240 | If wrapping is performed, point remains on the line. If the line does | |
241 | not need to be wrapped, move point to the next line and return t." | |
242 | (if (longlines-set-breakpoint) | |
cee723fb CY |
243 | (progn (insert-before-markers ?\n) |
244 | (backward-char 1) | |
245 | (delete-char -1) | |
246 | (forward-char 1) | |
cf6ffd8c RS |
247 | nil) |
248 | (if (longlines-merge-lines-p) | |
249 | (progn (end-of-line) | |
cf6ffd8c RS |
250 | ;; After certain commands (e.g. kill-line), there may be two |
251 | ;; successive soft newlines in the buffer. In this case, we | |
252 | ;; replace these two newlines by a single space. Unfortunately, | |
253 | ;; this breaks the conservation of (spaces + newlines), so we | |
254 | ;; have to fiddle with longlines-wrap-point. | |
e5ad37ee DK |
255 | (if (or (prog1 (bolp) (forward-char 1)) (eolp)) |
256 | (progn | |
257 | (delete-char -1) | |
258 | (if (> longlines-wrap-point (point)) | |
259 | (setq longlines-wrap-point | |
260 | (1- longlines-wrap-point)))) | |
261 | (insert-before-markers-and-inherit ?\ ) | |
262 | (backward-char 1) | |
263 | (delete-char -1) | |
264 | (forward-char 1)) | |
cf6ffd8c RS |
265 | nil) |
266 | (forward-line 1) | |
267 | t))) | |
268 | ||
269 | (defun longlines-set-breakpoint () | |
270 | "Place point where we should break the current line, and return t. | |
271 | If the line should not be broken, return nil; point remains on the | |
272 | line." | |
273 | (move-to-column fill-column) | |
274 | (if (and (re-search-forward "[^ ]" (line-end-position) 1) | |
275 | (> (current-column) fill-column)) | |
276 | ;; This line is too long. Can we break it? | |
277 | (or (longlines-find-break-backward) | |
278 | (progn (move-to-column fill-column) | |
279 | (longlines-find-break-forward))))) | |
280 | ||
281 | (defun longlines-find-break-backward () | |
282 | "Move point backward to the first available breakpoint and return t. | |
283 | If no breakpoint is found, return nil." | |
284 | (and (search-backward " " (line-beginning-position) 1) | |
285 | (save-excursion | |
286 | (skip-chars-backward " " (line-beginning-position)) | |
287 | (null (bolp))) | |
288 | (progn (forward-char 1) | |
289 | (if (and fill-nobreak-predicate | |
290 | (run-hook-with-args-until-success | |
291 | 'fill-nobreak-predicate)) | |
292 | (progn (skip-chars-backward " " (line-beginning-position)) | |
293 | (longlines-find-break-backward)) | |
294 | t)))) | |
295 | ||
296 | (defun longlines-find-break-forward () | |
297 | "Move point forward to the first available breakpoint and return t. | |
298 | If no break point is found, return nil." | |
299 | (and (search-forward " " (line-end-position) 1) | |
300 | (progn (skip-chars-forward " " (line-end-position)) | |
301 | (null (eolp))) | |
302 | (if (and fill-nobreak-predicate | |
303 | (run-hook-with-args-until-success | |
304 | 'fill-nobreak-predicate)) | |
305 | (longlines-find-break-forward) | |
306 | t))) | |
307 | ||
308 | (defun longlines-merge-lines-p () | |
309 | "Return t if part of the next line can fit onto the current line. | |
310 | Otherwise, return nil. Text cannot be moved across hard newlines." | |
311 | (save-excursion | |
312 | (end-of-line) | |
313 | (and (null (eobp)) | |
314 | (null (get-text-property (point) 'hard)) | |
315 | (let ((space (- fill-column (current-column)))) | |
316 | (forward-line 1) | |
317 | (if (eq (char-after) ? ) | |
318 | t ; We can always merge some spaces | |
319 | (<= (if (search-forward " " (line-end-position) 1) | |
320 | (current-column) | |
321 | (1+ (current-column))) | |
322 | space)))))) | |
323 | ||
0f157ad5 CY |
324 | (defun longlines-decode-region (&optional beg end) |
325 | "Turn all newlines between BEG and END into hard newlines. | |
326 | If BEG and END are nil, the point and mark are used." | |
327 | (if (null beg) (setq beg (point))) | |
328 | (if (null end) (setq end (mark t))) | |
cf6ffd8c | 329 | (save-excursion |
eb0d2864 CY |
330 | (let ((reg-max (max beg end))) |
331 | (goto-char (min beg end)) | |
332 | (while (search-forward "\n" reg-max t) | |
333 | (set-hard-newline-properties | |
334 | (match-beginning 0) (match-end 0)))))) | |
cf6ffd8c | 335 | |
2c127d45 CY |
336 | (defun longlines-decode-buffer () |
337 | "Turn all newlines in the buffer into hard newlines." | |
338 | (longlines-decode-region (point-min) (point-max))) | |
339 | ||
cf6ffd8c RS |
340 | (defun longlines-encode-region (beg end &optional buffer) |
341 | "Replace each soft newline between BEG and END with exactly one space. | |
342 | Hard newlines are left intact. The optional argument BUFFER exists for | |
343 | compatibility with `format-alist', and is ignored." | |
344 | (save-excursion | |
eb0d2864 CY |
345 | (let ((reg-max (max beg end)) |
346 | (mod (buffer-modified-p))) | |
cf6ffd8c | 347 | (goto-char (min beg end)) |
eb0d2864 | 348 | (while (search-forward "\n" reg-max t) |
cf6ffd8c RS |
349 | (unless (get-text-property (match-beginning 0) 'hard) |
350 | (replace-match " "))) | |
351 | (set-buffer-modified-p mod) | |
352 | end))) | |
353 | ||
354 | (defun longlines-encode-string (string) | |
355 | "Return a copy of STRING with each soft newline replaced by a space. | |
356 | Hard newlines are left intact." | |
357 | (let* ((str (copy-sequence string)) | |
358 | (pos (string-match "\n" str))) | |
359 | (while pos | |
360 | (if (null (get-text-property pos 'hard str)) | |
361 | (aset str pos ? )) | |
362 | (setq pos (string-match "\n" str (1+ pos)))) | |
363 | str)) | |
364 | ||
365 | ;; Auto wrap | |
366 | ||
367 | (defun longlines-auto-wrap (&optional arg) | |
368 | "Turn on automatic line wrapping, and wrap the entire buffer. | |
369 | With optional argument ARG, turn off line wrapping." | |
370 | (interactive "P") | |
371 | (remove-hook 'after-change-functions 'longlines-after-change-function t) | |
372 | (remove-hook 'post-command-hook 'longlines-post-command-function t) | |
373 | (if arg | |
374 | (progn (setq longlines-auto-wrap nil) | |
375 | (message "Auto wrap disabled.")) | |
376 | (setq longlines-auto-wrap t) | |
377 | (add-hook 'after-change-functions | |
378 | 'longlines-after-change-function nil t) | |
379 | (add-hook 'post-command-hook | |
380 | 'longlines-post-command-function nil t) | |
381 | (let ((mod (buffer-modified-p))) | |
382 | (longlines-wrap-region (point-min) (point-max)) | |
383 | (set-buffer-modified-p mod)) | |
384 | (message "Auto wrap enabled."))) | |
385 | ||
386 | (defun longlines-after-change-function (beg end len) | |
387 | "Update `longlines-wrap-beg' and `longlines-wrap-end'. | |
388 | This is called by `after-change-functions' to keep track of the region | |
389 | that has changed." | |
390 | (unless undo-in-progress | |
391 | (setq longlines-wrap-beg | |
392 | (if longlines-wrap-beg (min longlines-wrap-beg beg) beg)) | |
393 | (setq longlines-wrap-end | |
394 | (if longlines-wrap-end (max longlines-wrap-end end) end)))) | |
395 | ||
396 | (defun longlines-post-command-function () | |
397 | "Perform line wrapping on the parts of the buffer that have changed. | |
398 | This is called by `post-command-hook' after each command." | |
399 | (when longlines-wrap-beg | |
e17833bc CY |
400 | (if (or (eq this-command 'yank) |
401 | (eq this-command 'yank-pop)) | |
402 | (longlines-decode-region (point) (mark t))) | |
403 | (if longlines-showing | |
404 | (longlines-show-region longlines-wrap-beg longlines-wrap-end)) | |
cf6ffd8c RS |
405 | (unless (or (eq this-command 'fill-paragraph) |
406 | (eq this-command 'fill-region)) | |
407 | (longlines-wrap-region longlines-wrap-beg longlines-wrap-end)) | |
408 | (setq longlines-wrap-beg nil) | |
409 | (setq longlines-wrap-end nil))) | |
410 | ||
411 | (defun longlines-window-change-function () | |
412 | "Re-wrap the buffer if the window width has changed. | |
413 | This is called by `window-size-change-functions'." | |
414 | (when (/= fill-column (- (window-width) window-min-width)) | |
415 | (setq fill-column (- (window-width) window-min-width)) | |
416 | (let ((mod (buffer-modified-p))) | |
417 | (longlines-wrap-region (point-min) (point-max)) | |
418 | (set-buffer-modified-p mod)))) | |
419 | ||
930aae96 CY |
420 | ;; Isearch |
421 | ||
7f5bb182 | 422 | (defun longlines-search-function () |
930aae96 CY |
423 | (cond |
424 | (isearch-word | |
425 | (if isearch-forward 'word-search-forward 'word-search-backward)) | |
426 | (isearch-regexp | |
427 | (if isearch-forward 're-search-forward 're-search-backward)) | |
428 | (t | |
429 | (if isearch-forward | |
430 | 'longlines-search-forward | |
431 | 'longlines-search-backward)))) | |
432 | ||
433 | (defun longlines-search-forward (string &optional bound noerror count) | |
625fca9a | 434 | (let ((search-spaces-regexp "[ \n]+")) |
930aae96 CY |
435 | (re-search-forward (regexp-quote string) bound noerror count))) |
436 | ||
437 | (defun longlines-search-backward (string &optional bound noerror count) | |
625fca9a | 438 | (let ((search-spaces-regexp "[ \n]+")) |
930aae96 CY |
439 | (re-search-backward (regexp-quote string) bound noerror count))) |
440 | ||
cf6ffd8c RS |
441 | ;; Loading and saving |
442 | ||
b39aa4fd CY |
443 | (defun longlines-before-revert-hook () |
444 | (add-hook 'after-revert-hook 'longlines-after-revert-hook nil t) | |
445 | (longlines-mode 0)) | |
446 | ||
447 | (defun longlines-after-revert-hook () | |
448 | (remove-hook 'after-revert-hook 'longlines-after-revert-hook t) | |
449 | (longlines-mode 1)) | |
450 | ||
cf6ffd8c RS |
451 | (add-to-list |
452 | 'format-alist | |
c613b39c | 453 | (list 'longlines "Automatically wrap long lines." nil nil |
b39aa4fd | 454 | 'longlines-encode-region t nil)) |
cf6ffd8c RS |
455 | |
456 | (provide 'longlines) | |
457 | ||
96a29ab7 | 458 | ;; arch-tag: 3489d225-5506-47b9-8659-d8807b77c624 |
cf6ffd8c | 459 | ;;; longlines.el ends here |