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1 | ;;; refill.el --- `auto-fill' by refilling paragraphs on changes |
2 | ||
acaf905b | 3 | ;; Copyright (C) 2000-2012 Free Software Foundation, Inc. |
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4 | |
5 | ;; Author: Dave Love <fx@gnu.org> | |
a2515a78 | 6 | ;; Maintainer: Miles Bader <miles@gnu.org> |
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7 | ;; Keywords: wp |
8 | ||
2be7dabc GM |
9 | ;; This file is part of GNU Emacs. |
10 | ||
1fecc8fe | 11 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
aaaf7be7 | 12 | ;; it under the terms of the GNU General Public License as published by |
1fecc8fe GM |
13 | ;; the Free Software Foundation, either version 3 of the License, or |
14 | ;; (at your option) any later version. | |
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15 | |
16 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
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17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | ;; GNU General Public License for more details. | |
2be7dabc | 20 | |
aaaf7be7 | 21 | ;; You should have received a copy of the GNU General Public License |
1fecc8fe | 22 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
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23 | |
24 | ;;; Commentary: | |
25 | ||
26 | ;; Provides a mode where paragraphs are refilled after changes in them | |
7850e188 | 27 | ;; (using `after-change-functions'). This gives something akin to typical |
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28 | ;; word processor-style filling. We restrict refilling due to |
29 | ;; self-insertion to the characters which trigger auto-fill. | |
30 | ||
31 | ;; It partly satisfies a todo item in enriched.el for some value of | |
32 | ;; `without slowing down editing too much'. It doesn't attempt to do | |
33 | ;; anything (using `window-size-change-functions'?) about resizing | |
34 | ;; windows -- who cares? | |
35 | ||
36 | ;; This implementation is probably fragile and missing some special | |
37 | ;; cases -- not extensively tested. Yanking paragraph breaks, for | |
38 | ;; instance, won't DTRT by refilling all the relevant paragraphs. | |
39 | ||
40 | ;; You could do it a bit more efficiently (and robustly?) with just an | |
41 | ;; auto-fill function, but that doesn't cope with changes other than | |
42 | ;; through self-insertion. (Using auto-fill and after-change | |
43 | ;; functions together didn't seem winning.) This could probably | |
44 | ;; benefit from a less-general and faster `fill-paragraph-function', | |
45 | ;; ideally as a primitive. | |
46 | ||
47 | ;; The work is done in a local post-command hook but only if | |
48 | ;; `refill-doit' has been set by the after-change function. Using | |
7850e188 | 49 | ;; `post-command-hook' ensures simply that refilling only happens |
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50 | ;; once per command. |
51 | ||
52 | ;; [Per Abrahamsen's maniac.el does a similar thing, but operates from | |
53 | ;; post-command-hook. I don't understand the statement in it that | |
7850e188 | 54 | ;; after-change-functions don't work for this purpose; perhaps there was |
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55 | ;; some Emacs bug at the time. ISTR maniac has problems with |
56 | ;; whitespace at the end of paragraphs.] | |
57 | ||
d1a27f1d SM |
58 | ;;; Todo/Bugs: |
59 | ||
60 | ;; - When deleting the first word on a line, the space after that word tends | |
61 | ;; to become part of the fill-prefix, causing either wrong filling of the | |
62 | ;; remaining text, or causing the cursor to move unexpectedly. Ex: | |
63 | ;; Start with | |
64 | ;; I>< blabla | |
65 | ;; | |
66 | ;; and hit backspace. We end up with | |
67 | ;; | |
68 | ;; ><blabla | |
69 | ;; instead of | |
70 | ;; >< blabla | |
71 | ;; | |
72 | ;; Other example. Start with | |
73 | ;; | |
74 | ;; Foo bar blablabla asdgf | |
75 | ;; word>< asdfas dfasdfasd | |
76 | ;; asd asdfa sdfasd sdf | |
77 | ;; | |
78 | ;; and hit M-backspace. We end up with | |
79 | ;; | |
80 | ;; Foo bar blablabla asdgf | |
81 | ;; ><asdfas dfasdfasd asd | |
82 | ;; asdfa sdfasd sdf | |
83 | ||
aaaf7be7 DL |
84 | ;;; Code: |
85 | ||
e4caa91a MR |
86 | (defgroup refill nil |
87 | "Refilling paragraphs on changes." | |
88 | :group 'fill) | |
89 | ||
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90 | (defvar refill-ignorable-overlay nil |
91 | "Portion of the most recently filled paragraph not needing filling. | |
92 | This is used to optimize refilling.") | |
93 | (make-variable-buffer-local 'refill-ignorable-overlay) | |
94 | ||
95 | (defun refill-adjust-ignorable-overlay (overlay afterp beg end &optional len) | |
96 | "Adjust OVERLAY to not include the about-to-be-modified region." | |
97 | (when (not afterp) | |
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98 | (save-excursion |
99 | (goto-char beg) | |
100 | (forward-line -1) | |
101 | (if (<= (point) (overlay-start overlay)) | |
102 | ;; Just get OVERLAY out of the way | |
ad2feb08 | 103 | (move-overlay overlay (point-min) (point-min)) |
db95369b | 104 | ;; Make overlay contain only the region |
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105 | (move-overlay overlay (overlay-start overlay) (point)))))) |
106 | ||
107 | (defun refill-fill-paragraph-at (pos &optional arg) | |
108 | "Like `fill-paragraph' at POS, but don't delete whitespace at paragraph end." | |
ad2feb08 SM |
109 | (save-excursion |
110 | (goto-char pos) | |
111 | ;; FIXME: forward-paragraph seems to disregard `use-hard-newlines', | |
112 | ;; leading to excessive refilling and wrong choice of fill-prefix. | |
113 | ;; might be a bug in my paragraphs.el. | |
114 | (forward-paragraph) | |
115 | (skip-syntax-backward "-") | |
116 | (let ((end (point)) | |
117 | (beg (progn (backward-paragraph) (point))) | |
118 | (obeg (overlay-start refill-ignorable-overlay)) | |
119 | (oend (overlay-end refill-ignorable-overlay))) | |
120 | (unless (> beg pos) ;Don't fill if point is outside the paragraph. | |
121 | (goto-char pos) | |
122 | (if (and (>= beg obeg) (< beg oend)) | |
123 | ;; Limit filling to the modified tail of the paragraph. | |
124 | (let ( ;; When adaptive-fill-mode is enabled, the filling | |
125 | ;; functions will attempt to set the fill prefix from | |
126 | ;; the fake paragraph bounds we pass in, so set it | |
127 | ;; ourselves first, using the real paragraph bounds. | |
128 | (fill-prefix | |
129 | (if (and adaptive-fill-mode | |
130 | (or (null fill-prefix) (string= fill-prefix ""))) | |
131 | (fill-context-prefix beg end) | |
132 | fill-prefix)) | |
133 | ;; Turn off adaptive-fill-mode temporarily | |
134 | (adaptive-fill-mode nil)) | |
135 | (save-restriction | |
136 | (if use-hard-newlines | |
137 | (fill-region oend end arg) | |
138 | (fill-region-as-paragraph oend end arg))) | |
139 | (move-overlay refill-ignorable-overlay obeg (point))) | |
140 | ;; Fill the whole paragraph | |
141 | (save-restriction | |
142 | (if use-hard-newlines | |
143 | (fill-region beg end arg) | |
144 | (fill-region-as-paragraph beg end arg))) | |
145 | (move-overlay refill-ignorable-overlay beg (point))))))) | |
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146 | |
147 | (defun refill-fill-paragraph (arg) | |
148 | "Like `fill-paragraph' but don't delete whitespace at paragraph end." | |
149 | (refill-fill-paragraph-at (point) arg)) | |
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150 | |
151 | (defvar refill-doit nil | |
8b4703c4 | 152 | "Non-nil tells `refill-post-command-function' to do its processing. |
7850e188 | 153 | Set by `refill-after-change-function' in `after-change-functions' and |
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154 | unset by `refill-post-command-function' in `post-command-hook', and |
155 | sometimes `refill-pre-command-function' in `pre-command-hook'. This | |
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156 | ensures refilling is only done once per command that causes a change, |
157 | regardless of the number of after-change calls from commands doing | |
158 | complex processing.") | |
159 | (make-variable-buffer-local 'refill-doit) | |
160 | ||
161 | (defun refill-after-change-function (beg end len) | |
162 | "Function for `after-change-functions' which just sets `refill-doit'." | |
163 | (unless undo-in-progress | |
867092e9 | 164 | (setq refill-doit end))) |
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165 | |
166 | (defun refill-post-command-function () | |
167 | "Post-command function to do refilling (conditionally)." | |
867092e9 | 168 | (when refill-doit ; there was a change |
aaaf7be7 | 169 | ;; There's probably scope for more special cases here... |
a464a6c7 SM |
170 | (pcase this-command |
171 | (`self-insert-command | |
04138be8 SM |
172 | ;; Treat self-insertion commands specially, since they don't |
173 | ;; always reset `refill-doit' -- for self-insertion commands that | |
174 | ;; *don't* cause a refill, we want to leave it turned on so that | |
175 | ;; any subsequent non-modification command will cause a refill. | |
176 | (when (aref auto-fill-chars (char-before)) | |
177 | ;; Respond to the same characters as auto-fill (other than | |
178 | ;; newline, covered below). | |
179 | (refill-fill-paragraph-at refill-doit) | |
180 | (setq refill-doit nil))) | |
a464a6c7 SM |
181 | ((or `quoted-insert `fill-paragraph `fill-region) nil) |
182 | ((or `newline `newline-and-indent `open-line `indent-new-comment-line | |
183 | `reindent-then-newline-and-indent) | |
04138be8 SM |
184 | ;; Don't zap what was just inserted. |
185 | (save-excursion | |
186 | (beginning-of-line) ; for newline-and-indent | |
187 | (skip-chars-backward "\n") | |
188 | (save-restriction | |
189 | (narrow-to-region (point-min) (point)) | |
190 | (refill-fill-paragraph-at refill-doit))) | |
191 | (widen) | |
192 | (save-excursion | |
193 | (skip-chars-forward "\n") | |
194 | (save-restriction | |
195 | (narrow-to-region (line-beginning-position) (point-max)) | |
196 | (refill-fill-paragraph-at refill-doit)))) | |
a464a6c7 | 197 | (_ |
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198 | (refill-fill-paragraph-at refill-doit))) |
199 | (setq refill-doit nil))) | |
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200 | |
201 | (defun refill-pre-command-function () | |
202 | "Pre-command function to do refilling (conditionally)." | |
203 | (when (and refill-doit (not (eq this-command 'self-insert-command))) | |
204 | ;; A previous setting of `refill-doit' didn't result in a refill, | |
205 | ;; because it was a self-insert-command. Since the next command is | |
206 | ;; something else, do the refill now. | |
207 | (refill-fill-paragraph-at refill-doit) | |
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208 | (setq refill-doit nil))) |
209 | ||
04138be8 | 210 | (defvar refill-saved-state nil) |
10ee3d79 | 211 | |
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212 | ;;;###autoload |
213 | (define-minor-mode refill-mode | |
ac6c8639 CY |
214 | "Toggle automatic refilling (Refill mode). |
215 | With a prefix argument ARG, enable Refill mode if ARG is | |
216 | positive, and disable it otherwise. If called from Lisp, enable | |
217 | the mode if ARG is omitted or nil. | |
aaaf7be7 | 218 | |
ac6c8639 CY |
219 | Refill mode is a buffer-local minor mode. When enabled, the |
220 | current paragraph is refilled as you edit. Self-inserting | |
221 | characters only cause refilling if they would cause | |
222 | auto-filling. | |
223 | ||
224 | For true \"word wrap\" behavior, use `visual-line-mode' instead." | |
6de274aa LK |
225 | :group 'refill |
226 | :lighter " Refill" | |
227 | :keymap '(("\177" . backward-delete-char-untabify)) | |
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228 | ;; Remove old state if necessary |
229 | (when refill-ignorable-overlay | |
230 | (delete-overlay refill-ignorable-overlay) | |
231 | (kill-local-variable 'refill-ignorable-overlay)) | |
04138be8 SM |
232 | (when (local-variable-p 'refill-saved-state) |
233 | (dolist (x refill-saved-state) | |
234 | (set (make-local-variable (car x)) (cdr x))) | |
235 | (kill-local-variable 'refill-saved-state)) | |
aaaf7be7 | 236 | (if refill-mode |
7850e188 SM |
237 | (progn |
238 | (add-hook 'after-change-functions 'refill-after-change-function nil t) | |
239 | (add-hook 'post-command-hook 'refill-post-command-function nil t) | |
867092e9 | 240 | (add-hook 'pre-command-hook 'refill-pre-command-function nil t) |
04138be8 SM |
241 | (set (make-local-variable 'refill-saved-state) |
242 | (mapcar (lambda (s) (cons s (symbol-value s))) | |
243 | '(fill-paragraph-function auto-fill-function))) | |
f5bd4bf2 | 244 | ;; This provides the test for recursive paragraph filling. |
7850e188 SM |
245 | (set (make-local-variable 'fill-paragraph-function) |
246 | 'refill-fill-paragraph) | |
d1a27f1d SM |
247 | ;; When using justification, doing DEL on 2 spaces should remove |
248 | ;; both, otherwise, the subsequent refill will undo the DEL. | |
249 | (set (make-local-variable 'backward-delete-char-untabify-method) | |
250 | 'hungry) | |
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251 | (setq refill-ignorable-overlay (make-overlay 1 1 nil nil t)) |
252 | (overlay-put refill-ignorable-overlay 'modification-hooks | |
253 | '(refill-adjust-ignorable-overlay)) | |
254 | (overlay-put refill-ignorable-overlay 'insert-behind-hooks | |
255 | '(refill-adjust-ignorable-overlay)) | |
7850e188 | 256 | (auto-fill-mode 0)) |
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257 | (remove-hook 'after-change-functions 'refill-after-change-function t) |
258 | (remove-hook 'post-command-hook 'refill-post-command-function t) | |
d1a27f1d | 259 | (kill-local-variable 'backward-delete-char-untabify-method))) |
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260 | |
261 | (provide 'refill) | |
262 | ||
263 | ;;; refill.el ends here |