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1 | ;;; refill.el --- `auto-fill' by refilling paragraphs on changes |
2 | ||
3731a850 | 3 | ;; Copyright (C) 2000, 2002, 2003, 2004, 2005 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 | ||
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9 | ;; This file is part of GNU Emacs. |
10 | ||
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 |
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13 | ;; the Free Software Foundation; either version 2, or (at your option) |
14 | ;; any later version. | |
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 |
2be7dabc | 22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
4fc5845f LK |
23 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
24 | ;; Boston, MA 02110-1301, USA. | |
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25 | |
26 | ;;; Commentary: | |
27 | ||
28 | ;; Provides a mode where paragraphs are refilled after changes in them | |
7850e188 | 29 | ;; (using `after-change-functions'). This gives something akin to typical |
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30 | ;; word processor-style filling. We restrict refilling due to |
31 | ;; self-insertion to the characters which trigger auto-fill. | |
32 | ||
33 | ;; It partly satisfies a todo item in enriched.el for some value of | |
34 | ;; `without slowing down editing too much'. It doesn't attempt to do | |
35 | ;; anything (using `window-size-change-functions'?) about resizing | |
36 | ;; windows -- who cares? | |
37 | ||
38 | ;; This implementation is probably fragile and missing some special | |
39 | ;; cases -- not extensively tested. Yanking paragraph breaks, for | |
40 | ;; instance, won't DTRT by refilling all the relevant paragraphs. | |
41 | ||
42 | ;; You could do it a bit more efficiently (and robustly?) with just an | |
43 | ;; auto-fill function, but that doesn't cope with changes other than | |
44 | ;; through self-insertion. (Using auto-fill and after-change | |
45 | ;; functions together didn't seem winning.) This could probably | |
46 | ;; benefit from a less-general and faster `fill-paragraph-function', | |
47 | ;; ideally as a primitive. | |
48 | ||
49 | ;; The work is done in a local post-command hook but only if | |
50 | ;; `refill-doit' has been set by the after-change function. Using | |
7850e188 | 51 | ;; `post-command-hook' ensures simply that refilling only happens |
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52 | ;; once per command. |
53 | ||
54 | ;; [Per Abrahamsen's maniac.el does a similar thing, but operates from | |
55 | ;; post-command-hook. I don't understand the statement in it that | |
7850e188 | 56 | ;; after-change-functions don't work for this purpose; perhaps there was |
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57 | ;; some Emacs bug at the time. ISTR maniac has problems with |
58 | ;; whitespace at the end of paragraphs.] | |
59 | ||
d1a27f1d SM |
60 | ;;; Todo/Bugs: |
61 | ||
62 | ;; - When deleting the first word on a line, the space after that word tends | |
63 | ;; to become part of the fill-prefix, causing either wrong filling of the | |
64 | ;; remaining text, or causing the cursor to move unexpectedly. Ex: | |
65 | ;; Start with | |
66 | ;; I>< blabla | |
67 | ;; | |
68 | ;; and hit backspace. We end up with | |
69 | ;; | |
70 | ;; ><blabla | |
71 | ;; instead of | |
72 | ;; >< blabla | |
73 | ;; | |
74 | ;; Other example. Start with | |
75 | ;; | |
76 | ;; Foo bar blablabla asdgf | |
77 | ;; word>< asdfas dfasdfasd | |
78 | ;; asd asdfa sdfasd sdf | |
79 | ;; | |
80 | ;; and hit M-backspace. We end up with | |
81 | ;; | |
82 | ;; Foo bar blablabla asdgf | |
83 | ;; ><asdfas dfasdfasd asd | |
84 | ;; asdfa sdfasd sdf | |
85 | ||
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86 | ;;; Code: |
87 | ||
04138be8 SM |
88 | (eval-when-compile (require 'cl)) |
89 | ||
e4caa91a MR |
90 | (defgroup refill nil |
91 | "Refilling paragraphs on changes." | |
92 | :group 'fill) | |
93 | ||
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94 | (defvar refill-ignorable-overlay nil |
95 | "Portion of the most recently filled paragraph not needing filling. | |
96 | This is used to optimize refilling.") | |
97 | (make-variable-buffer-local 'refill-ignorable-overlay) | |
98 | ||
99 | (defun refill-adjust-ignorable-overlay (overlay afterp beg end &optional len) | |
100 | "Adjust OVERLAY to not include the about-to-be-modified region." | |
101 | (when (not afterp) | |
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102 | (save-excursion |
103 | (goto-char beg) | |
104 | (forward-line -1) | |
105 | (if (<= (point) (overlay-start overlay)) | |
106 | ;; Just get OVERLAY out of the way | |
ad2feb08 | 107 | (move-overlay overlay (point-min) (point-min)) |
db95369b | 108 | ;; Make overlay contain only the region |
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109 | (move-overlay overlay (overlay-start overlay) (point)))))) |
110 | ||
111 | (defun refill-fill-paragraph-at (pos &optional arg) | |
112 | "Like `fill-paragraph' at POS, but don't delete whitespace at paragraph end." | |
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113 | (save-excursion |
114 | (goto-char pos) | |
115 | ;; FIXME: forward-paragraph seems to disregard `use-hard-newlines', | |
116 | ;; leading to excessive refilling and wrong choice of fill-prefix. | |
117 | ;; might be a bug in my paragraphs.el. | |
118 | (forward-paragraph) | |
119 | (skip-syntax-backward "-") | |
120 | (let ((end (point)) | |
121 | (beg (progn (backward-paragraph) (point))) | |
122 | (obeg (overlay-start refill-ignorable-overlay)) | |
123 | (oend (overlay-end refill-ignorable-overlay))) | |
124 | (unless (> beg pos) ;Don't fill if point is outside the paragraph. | |
125 | (goto-char pos) | |
126 | (if (and (>= beg obeg) (< beg oend)) | |
127 | ;; Limit filling to the modified tail of the paragraph. | |
128 | (let ( ;; When adaptive-fill-mode is enabled, the filling | |
129 | ;; functions will attempt to set the fill prefix from | |
130 | ;; the fake paragraph bounds we pass in, so set it | |
131 | ;; ourselves first, using the real paragraph bounds. | |
132 | (fill-prefix | |
133 | (if (and adaptive-fill-mode | |
134 | (or (null fill-prefix) (string= fill-prefix ""))) | |
135 | (fill-context-prefix beg end) | |
136 | fill-prefix)) | |
137 | ;; Turn off adaptive-fill-mode temporarily | |
138 | (adaptive-fill-mode nil)) | |
139 | (save-restriction | |
140 | (if use-hard-newlines | |
141 | (fill-region oend end arg) | |
142 | (fill-region-as-paragraph oend end arg))) | |
143 | (move-overlay refill-ignorable-overlay obeg (point))) | |
144 | ;; Fill the whole paragraph | |
145 | (save-restriction | |
146 | (if use-hard-newlines | |
147 | (fill-region beg end arg) | |
148 | (fill-region-as-paragraph beg end arg))) | |
149 | (move-overlay refill-ignorable-overlay beg (point))))))) | |
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150 | |
151 | (defun refill-fill-paragraph (arg) | |
152 | "Like `fill-paragraph' but don't delete whitespace at paragraph end." | |
153 | (refill-fill-paragraph-at (point) arg)) | |
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154 | |
155 | (defvar refill-doit nil | |
8b4703c4 | 156 | "Non-nil tells `refill-post-command-function' to do its processing. |
7850e188 | 157 | Set by `refill-after-change-function' in `after-change-functions' and |
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158 | unset by `refill-post-command-function' in `post-command-hook', and |
159 | sometimes `refill-pre-command-function' in `pre-command-hook'. This | |
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160 | ensures refilling is only done once per command that causes a change, |
161 | regardless of the number of after-change calls from commands doing | |
162 | complex processing.") | |
163 | (make-variable-buffer-local 'refill-doit) | |
164 | ||
165 | (defun refill-after-change-function (beg end len) | |
166 | "Function for `after-change-functions' which just sets `refill-doit'." | |
167 | (unless undo-in-progress | |
867092e9 | 168 | (setq refill-doit end))) |
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169 | |
170 | (defun refill-post-command-function () | |
171 | "Post-command function to do refilling (conditionally)." | |
867092e9 | 172 | (when refill-doit ; there was a change |
aaaf7be7 | 173 | ;; There's probably scope for more special cases here... |
04138be8 SM |
174 | (case this-command |
175 | (self-insert-command | |
176 | ;; Treat self-insertion commands specially, since they don't | |
177 | ;; always reset `refill-doit' -- for self-insertion commands that | |
178 | ;; *don't* cause a refill, we want to leave it turned on so that | |
179 | ;; any subsequent non-modification command will cause a refill. | |
180 | (when (aref auto-fill-chars (char-before)) | |
181 | ;; Respond to the same characters as auto-fill (other than | |
182 | ;; newline, covered below). | |
183 | (refill-fill-paragraph-at refill-doit) | |
184 | (setq refill-doit nil))) | |
185 | ((quoted-insert fill-paragraph fill-region) nil) | |
186 | ((newline newline-and-indent open-line indent-new-comment-line | |
187 | reindent-then-newline-and-indent) | |
188 | ;; Don't zap what was just inserted. | |
189 | (save-excursion | |
190 | (beginning-of-line) ; for newline-and-indent | |
191 | (skip-chars-backward "\n") | |
192 | (save-restriction | |
193 | (narrow-to-region (point-min) (point)) | |
194 | (refill-fill-paragraph-at refill-doit))) | |
195 | (widen) | |
196 | (save-excursion | |
197 | (skip-chars-forward "\n") | |
198 | (save-restriction | |
199 | (narrow-to-region (line-beginning-position) (point-max)) | |
200 | (refill-fill-paragraph-at refill-doit)))) | |
201 | (t | |
202 | (refill-fill-paragraph-at refill-doit))) | |
203 | (setq refill-doit nil))) | |
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204 | |
205 | (defun refill-pre-command-function () | |
206 | "Pre-command function to do refilling (conditionally)." | |
207 | (when (and refill-doit (not (eq this-command 'self-insert-command))) | |
208 | ;; A previous setting of `refill-doit' didn't result in a refill, | |
209 | ;; because it was a self-insert-command. Since the next command is | |
210 | ;; something else, do the refill now. | |
211 | (refill-fill-paragraph-at refill-doit) | |
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212 | (setq refill-doit nil))) |
213 | ||
04138be8 | 214 | (defvar refill-saved-state nil) |
10ee3d79 | 215 | |
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216 | ;;;###autoload |
217 | (define-minor-mode refill-mode | |
218 | "Toggle Refill minor mode. | |
219 | With prefix arg, turn Refill mode on iff arg is positive. | |
220 | ||
221 | When Refill mode is on, the current paragraph will be formatted when | |
222 | changes are made within it. Self-inserting characters only cause | |
223 | refilling if they would cause auto-filling." | |
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224 | :group 'refill |
225 | :lighter " Refill" | |
226 | :keymap '(("\177" . backward-delete-char-untabify)) | |
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227 | ;; Remove old state if necessary |
228 | (when refill-ignorable-overlay | |
229 | (delete-overlay refill-ignorable-overlay) | |
230 | (kill-local-variable 'refill-ignorable-overlay)) | |
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231 | (when (local-variable-p 'refill-saved-state) |
232 | (dolist (x refill-saved-state) | |
233 | (set (make-local-variable (car x)) (cdr x))) | |
234 | (kill-local-variable 'refill-saved-state)) | |
aaaf7be7 | 235 | (if refill-mode |
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236 | (progn |
237 | (add-hook 'after-change-functions 'refill-after-change-function nil t) | |
238 | (add-hook 'post-command-hook 'refill-post-command-function nil t) | |
867092e9 | 239 | (add-hook 'pre-command-hook 'refill-pre-command-function nil t) |
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240 | (set (make-local-variable 'refill-saved-state) |
241 | (mapcar (lambda (s) (cons s (symbol-value s))) | |
242 | '(fill-paragraph-function auto-fill-function))) | |
f5bd4bf2 | 243 | ;; This provides the test for recursive paragraph filling. |
7850e188 SM |
244 | (set (make-local-variable 'fill-paragraph-function) |
245 | 'refill-fill-paragraph) | |
d1a27f1d SM |
246 | ;; When using justification, doing DEL on 2 spaces should remove |
247 | ;; both, otherwise, the subsequent refill will undo the DEL. | |
248 | (set (make-local-variable 'backward-delete-char-untabify-method) | |
249 | 'hungry) | |
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250 | (setq refill-ignorable-overlay (make-overlay 1 1 nil nil t)) |
251 | (overlay-put refill-ignorable-overlay 'modification-hooks | |
252 | '(refill-adjust-ignorable-overlay)) | |
253 | (overlay-put refill-ignorable-overlay 'insert-behind-hooks | |
254 | '(refill-adjust-ignorable-overlay)) | |
7850e188 | 255 | (auto-fill-mode 0)) |
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256 | (remove-hook 'after-change-functions 'refill-after-change-function t) |
257 | (remove-hook 'post-command-hook 'refill-post-command-function t) | |
d1a27f1d | 258 | (kill-local-variable 'backward-delete-char-untabify-method))) |
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259 | |
260 | (provide 'refill) | |
261 | ||
04138be8 | 262 | ;; arch-tag: 2c4ce9e8-1daa-4a3b-b6f8-fd6ac5bf6138 |
aaaf7be7 | 263 | ;;; refill.el ends here |