(Quitting): Minor clarification.
[bpt/emacs.git] / lisp / textmodes / two-column.el
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1;;; two-column.el --- minor mode for editing of two-column text
2
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3;; Copyright (C) 1992, 1993, 1994, 1995, 2002, 2003, 2004,
4;; 2005 Free Software Foundation, Inc.
e6b72410 5
3e910376 6;; Author: Daniel Pfeiffer <occitan@esperanto.org>
e6b72410 7;; Adapted-By: ESR, Daniel Pfeiffer
6228c05b 8;; Keywords: wp
e6b72410 9
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10;; This file is part of GNU Emacs.
11
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12;; Esperanto: English:
13
14;; ^Ci dosiero estas ero de GNU Emacs. This file is part of GNU Emacs.
15
16;; GNU Emacs estas libera programaro; GNU Emacs is free software; you can
17;; vi povas disdoni ^gin kaj/a^u modifi redistribute it and/or modify it
18;; ^gin sub la kondi^coj de la GNU under the terms of the GNU General
19;; ^Generala Publika Licenco kiel pub- Public License as published by the
20;; likigita far la Liberprogramara Fon- Free Software Foundation; either
21;; da^jo; a^u eldono 2a, a^u (la^u via version 2, or (at your option) any
22;; elekto) ajna posta eldono. later version.
23
24;; GNU Emacs estas disdonata en la GNU Emacs is distributed in the hope
25;; espero ke ^gi estos utila, sed SEN that it will be useful, but WITHOUT
26;; IA GARANTIO; sen e^c la implicita ANY WARRANTY; without even the
27;; garantio de VENDEBLECO a^u PRETECO implied warranty of MERCHANTABILITY
28;; POR DETERMINITA CELO. Vidu la GNU or FITNESS FOR A PARTICULAR PURPOSE.
29;; ^Generala Publika Licenco por plenaj See the GNU General Public License
30;; detaloj. for more details.
31
32;; Vi devus ricevinti kopion de la GNU You should have received a copy of
33;; ^Generala Publika Licenco kune kun the GNU General Public License along
34;; GNU Emacs; vidu la dosieron COPYING. with GNU Emacs; see the file
35;; Alikaze skribu al la COPYING. If not, write to the
36
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37;; Free Software Foundation, 51 Franklin Street, Fifth Floor
38;; Boston, MA 02110-1301, USA.
e6b72410 39
e8af40ee 40;;; Commentary:
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41
42;;; Komentario: Commentary:
43
44;; Tiu programaro ebligas vin redakti This package gives you the ability
45;; dukolumnan tekston. to edit text in a two-column format.
46
47
48;; Vi havas tri eblecojn por eki tiun You have three ways to start up this
49;; mal^cefan modalon. ^Ciu donas al vi minor mode. Each gives you a
50;; horizontale disigatan fenestron, si- horizontally split window similar to
51;; milan al fina apareco de via teksto: the final outcome of your text:
52
53
54;; f2 2 asocias novan bufron nomatan associates a new buffer called
55;; C-x 6 2 same, sed kun 2C/ anta^u. the same, but with 2C/
56;; prepended.
57
58;; f2 b asocias alian bufron. Vi povas associates another buffer.
59;; C-x 6 b anka^u asocii dataron, se vi This can be used to associate a
60;; ^jus anta^ue faris C-x C-f. file if you just did C-x C-f.
61
62;; f2 s disigas jam dukolumnan tekston splits a two-column text into
63;; C-x 6 s en du bufroj ekde la nuna two buffers from the current
64;; linio, kaj je la nuna kolumno. line and at the current column.
65;; La anta^uaj signoj (ofte The preceding characters (often
66;; tabeligilo a^u |) estas la tab or |) are the column
67;; kolumna disiganto. Linioj kiuj separator. Lines that don't
68;; ne enhavas ilin ne estas have them won't be separated.
69;; disigitaj. Kiel la kvara kaj Like the fourth and fifth line
70;; la kvina linio se vi disigas if you split this file from
71;; ^ci dataron ekde la unua angla the first english word.
72;; vorto.
73
74;; Se vi volas meti longajn liniojn If you include long lines, i.e which
75;; (ekz. programerojn) en la kunigotan will span both columns (eg. source
76;; tekston, ili devas esti en la code), they should be in what will
77;; estonte unua kolumno. La alia devas be the first column, with the
78;; havi vakajn linion apud ili. associated buffer having empty lines
79;; next to them.
80
81;; Averto: en Emacs kiam vi ^san^gas la Attention: in Emacs when you change
82;; ^cefan modalon, la mal^cefaj modaloj the major mode, the minor modes are
83;; estas anka^u elmemorigitaj. Tiu- also purged from memory. In that
84;; okaze vi devas religi la du bufrojn case you must reassociate the two
85;; per iu C-x 6-ordono, ekz. C-x 6 b. buffers with any C-x 6-command, e.g.
86;; C-x 6 b.
87
88;; Kiam vi estos kontenta de la When you have edited both buffers to
89;; rezulto, vi kunmetos la du kolumnojn your content, you merge them with
90;; per C-x 6 1. Se vi poste vidas C-x 6 1. If you then see a problem,
91;; problemon, vi neniigu la kunmeton you undo the merge with C-x u and
92;; per C-x u kaj plue modifu la du continue to edit the two buffers.
93;; bufrojn. Kiam vi ne plu volas tajpi When you no longer want to edit in
94;; dukolumne, vi eliru el la mal^cefa two columns, you turn off the minor
95;; modalo per C-x 6 d. mode with C-x 6 d.
96
97
98;; Aldone al dukolumna redaktado, ek- In addition to two-column editing of
99;; zemple por skribi dulingvan tekston text, for example for writing a
100;; flank-al-flanke kiel ^ci tiu, aliaj bilingual text side-by-side as shown
101;; interesaj uzoj trovitas por tiu mal- here, other interesting uses have
102;; ^cefa modalo: been found for this minor mode:
103
104;; Vi povas disigi la kolumnojn per {+} You can separate the columns with
105;; ajna pla^ca ^ceno starigante {+} any string that pleases you, by
106;; `2C-separator'. Ekzemple "{+} " {+} setting `2C-separator'. For example
107;; por amuzi^gi. f2 s a^u C-x 6 s {+} "{+} " if you'd like to have fun.
108;; traktas tiujn kun prefiksa {+} f2 s or C-x 6 s handles these with a
109;; argumento kiu signifas la longon {+} prefix argument that means the
110;; de tia ^ceno. {+} desired length of such a string.
111
112
113;; Programistoj eble ^satus la eblecon Programmers might like the ability
114;; forspliti la komentarian kolumnon de to split off the comment column of a
115;; dosiero kiel la sekvanta. Vi povas file that looks like the following.
116;; rearan^gigi la paragrafon. La pro- You can fill-paragraph the comment.
117;; blemo estas ke koda^jo tuj lar- The problem is, code quickly gets
118;; ^gi^gas, tiel ke vi bezonas pli rather wide, so you need to use a
119;; mallar^gan komentarian kolumnon. narrower comment column. Code lines
120;; Koda^jaj linioj tra `comment-column' that reach beyond `comment-column'
121;; ne problemas, krom ke vi ne vidos are no problem, except that you
122;; iliajn finojn dum redaktado. won't see their end during editing.
123
124
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125;; BEGIN -- This is just some meaningless
126;; FOR i IN 1..10 LOOP -- code in Ada, that runs foobar
e6b72410 127;; foobar( i ); -- once for each argument from one
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128;; END LOOP; -- to ten, and then we're already
129;; END; -- through with it.
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130
131;; Pli bone ankora^u, vi povas pozici- Better yet, you can put the point
132;; i^gi anta^u "This", tajpi M-3 f2 s before "This", type M-3 f2 s
133;; kiu igas "-- " la separigilon inter which makes "-- " the separator
134;; senkomentaria Ada bufro kaj nur- between a no-comments Ada buffer,
135;; teksta komentaria bufro. Kiam vi and a plain text comment buffer.
136;; denove kuni^gos ilin, ^ciu nevaka When you put them back together,
137;; linio de l' dua kolumno denove every non-empty line of the 2nd
138;; anta^uhavos "-- ". column will again be preceded by
139;; "-- ".
140
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141
142;;; Code:
143\f
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144
145;; Lucid patch
146(or (fboundp 'frame-width)
147 (fset 'frame-width 'screen-width))
148
149
3bcbd523 150;;;;; Set up keymap ;;;;;
72c0ae01 151
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152(defvar 2C-mode-map
153 (let ((map (make-sparse-keymap)))
154 (define-key map "2" '2C-two-columns)
155 (define-key map [f2] '2C-two-columns)
156 (define-key map "b" '2C-associate-buffer)
157 (define-key map "s" '2C-split)
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158 map)
159 "Keymap for commands for setting up two-column mode.")
160
161
162
163;;;###autoload (autoload '2C-command "two-column" () t 'keymap)
164(fset '2C-command 2C-mode-map)
72c0ae01 165
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166;; This one is for historical reasons and simple keyboards, it is not
167;; at all mnemonic. All usual sequences containing 2 were used, and
168;; f2 could not be set up in a standard way under Emacs 18.
2c02e313 169;;;###autoload (global-set-key "\C-x6" '2C-command)
e6b72410 170
2c02e313 171;;;###autoload (global-set-key [f2] '2C-command)
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172
173
174(defvar 2C-minor-mode-map
175 (let ((map (make-sparse-keymap)))
176 (define-key map "1" '2C-merge)
177 (define-key map "d" '2C-dissociate)
178 (define-key map "o" '2C-associated-buffer)
8fe9ecef 179 (define-key map "\^m" '2C-newline)
e6b72410 180 (define-key map "|" '2C-toggle-autoscroll)
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181 (define-key map "{" '2C-shrink-window-horizontally)
182 (define-key map "}" '2C-enlarge-window-horizontally)
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183 map)
184 "Keymap for commands for use in two-column mode.")
185
186
187(setq minor-mode-map-alist
188 (cons (cons '2C-mode
189 (let ((map (make-sparse-keymap)))
190 (substitute-key-definition '2C-command 2C-minor-mode-map
191 map (current-global-map))
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192 (substitute-key-definition 'enlarge-window-horizontally
193 '2C-enlarge-window-horizontally
194 map (current-global-map))
195 (substitute-key-definition 'shrink-window-horizontally
196 '2C-shrink-window-horizontally
197 map (current-global-map))
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198 map))
199 minor-mode-map-alist))
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200\f
201;;;;; variable declarations ;;;;;
72c0ae01 202
ded3e3d8 203(defgroup two-column nil
5cbebcab 204 "Minor mode for editing of two-column text."
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205 :prefix "2C-"
206 :group 'frames)
207
208
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209;; Markers seem to be the only buffer-id not affected by renaming a buffer.
210;; This nevertheless loses when a buffer is killed. The variable-name is
211;; required by `describe-mode'.
212(defvar 2C-mode nil
72c0ae01 213 "Marker to the associated buffer, if non-nil.")
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214(make-variable-buffer-local '2C-mode)
215(put '2C-mode 'permanent-local t)
216
217
218
219(setq minor-mode-alist (cons '(2C-mode " 2C") minor-mode-alist))
220
72c0ae01 221
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222
223;; rearranged, so that the pertinent info will show in 40 columns
ded3e3d8 224(defcustom 2C-mode-line-format
72c0ae01 225 '("-%*- %15b --" (-3 . "%p") "--%[(" mode-name
e6b72410 226 minor-mode-alist "%n" mode-line-process ")%]%-")
431328cc 227 "*Value of `mode-line-format' for a buffer in two-column minor mode."
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228 :type 'sexp
229 :group 'two-column)
72c0ae01 230
e6b72410 231
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232(defcustom 2C-other-buffer-hook 'text-mode
233 "*Hook run in new buffer when it is associated with current one."
234 :type 'function
235 :group 'two-column)
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236
237
ded3e3d8 238(defcustom 2C-separator ""
72c0ae01 239 "*A string inserted between the two columns when merging.
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240This gets set locally by \\[2C-split]."
241 :type 'string
242 :group 'two-column)
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243(put '2C-separator 'permanent-local t)
244
245
72c0ae01 246
ded3e3d8 247(defcustom 2C-window-width 40
72c0ae01 248 "*The width of the first column. (Must be at least `window-min-width')
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249This value is local for every buffer that sets it."
250 :type 'integer
251 :group 'two-column)
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252(make-variable-buffer-local '2C-window-width)
253(put '2C-window-width 'permanent-local t)
72c0ae01 254
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255
256
ded3e3d8 257(defcustom 2C-beyond-fill-column 4
72c0ae01 258 "*Base for calculating `fill-column' for a buffer in two-column minor mode.
e6b72410 259The value of `fill-column' becomes `2C-window-width' for this buffer
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260minus this value."
261 :type 'integer
262 :group 'two-column)
72c0ae01 263
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264
265
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266(defcustom 2C-autoscroll t
267 "If non-nil, Emacs attempts to keep the two column's buffers aligned."
268 :type 'boolean
269 :group 'two-column)
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270
271
272
273(defvar 2C-autoscroll-start nil)
274(make-variable-buffer-local '2C-autoscroll-start)
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275\f
276;;;;; base functions ;;;;;
277
e6b72410 278;; The access method for the other buffer. This tries to remedy against
72c0ae01 279;; lost local variables and lost buffers.
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280(defun 2C-other (&optional req)
281 (or (if 2C-mode
282 (or (prog1
283 (marker-buffer 2C-mode)
284 (setq mode-line-format 2C-mode-line-format))
285 ;; The associated buffer somehow got killed.
286 (progn
287 ;; The other variables may later be useful if the user
288 ;; reestablishes the association.
289 (kill-local-variable '2C-mode)
290 (kill-local-variable 'mode-line-format)
291 nil)))
e8af40ee 292 (if req (error "You must first set two-column minor mode"))))
72c0ae01 293
72c0ae01 294
72c0ae01 295
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296;; function for setting up two-column minor mode in a buffer associated
297;; with the buffer pointed to by the marker other.
298(defun 2C-mode (other)
299 "Minor mode for independently editing two columns.
300This is set up for two associated buffers by the three commands bound
301to \\[2C-two-columns] , \\[2C-associate-buffer] and \\[2C-split].
302Turning on two-column mode calls the value of the variable `2C-mode-hook',
303if that value is non-nil.
304
305These buffers can be edited separately, for example with `fill-paragraph'.
306If you want to disable parallel scrolling temporarily, use \\[2C-toggle-autoscroll] .
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307
308If you include long lines, i.e which will span both columns (eg.
309source code), they should be in what will be the first column, with
310the associated buffer having empty lines next to them.
311
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312Potential uses are writing bilingual texts, or editing the comments of a
313source code. See the file lisp/two-column.el for detailed examples.
314
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315You have the following commands at your disposal:
316
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317\\[2C-two-columns] Rearrange screen with current buffer first
318\\[2C-associate-buffer] Reassociate buffer after changing major mode
72c0ae01 319\\[shrink-window-horizontally], \\[enlarge-window-horizontally] Shrink, enlarge current column
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320\\[2C-associated-buffer] Switch to associated buffer at same point
321\\[2C-newline] Insert newline(s) in both buffers at same point
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322\\[2C-merge] Merge both buffers
323\\[2C-dissociate] Dissociate the two buffers
72c0ae01 324
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325These keybindings can be customized in your ~/.emacs by `2C-mode-map',
326`2C-minor-mode-map' and by binding `2C-command' to some prefix.
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327
328The appearance of the screen can be customized by the variables
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329`2C-window-width', `2C-beyond-fill-column', `2C-mode-line-format' and
330`truncate-partial-width-windows'."
5181be3a 331 (add-hook 'post-command-hook '2C-autoscroll nil t)
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332 (setq fill-column (- 2C-window-width
333 2C-beyond-fill-column)
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334 mode-line-format 2C-mode-line-format
335 2C-mode other)
336 (run-hooks '2C-mode-hook))
337
338
72c0ae01 339
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340;;;###autoload
341(defun 2C-two-columns (&optional buffer)
342 "Split current window vertically for two-column editing.
343When called the first time, associates a buffer with the current
344buffer in two-column minor mode (see \\[describe-mode] ).
345Runs `2C-other-buffer-hook' in the new buffer.
346When called again, restores the screen layout with the current buffer
17c3470e 347first and the associated buffer to its right."
72c0ae01 348 (interactive "P")
e6b72410 349 ;; first go to full width, so that we can certainly split into two windows
3bcbd523 350 (if (< (window-width) (frame-width))
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351 (enlarge-window 99999 t))
352 (split-window-horizontally
e6b72410 353 (max window-min-width (min 2C-window-width
3bcbd523 354 (- (frame-width) window-min-width))))
e6b72410 355 (if (2C-other)
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356 (progn
357 (other-window 1)
e6b72410 358 (switch-to-buffer (2C-other))
72c0ae01 359 (other-window -1)
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360 (if 2C-autoscroll
361 (2C-toggle-autoscroll t)))
362
363 (2C-mode (prog1 (point-marker)
364 (other-window 1)
365 (switch-to-buffer
366 (or buffer
8fe9ecef 367 (generate-new-buffer (concat "2C/" (buffer-name)))))
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368 (or buffer
369 (run-hooks '2C-other-buffer-hook))))
eaae8106 370
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371 (2C-mode (prog1 (point-marker)
372 (other-window -1)))))
373
374
72c0ae01 375
6f5191a2 376;;;###autoload
e6b72410 377(defun 2C-associate-buffer ()
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378 "Associate another buffer with this one in two-column minor mode.
379Can also be used to associate a just previously visited file, by
380accepting the proposed default buffer.
381
e6b72410 382\(See \\[describe-mode] .)"
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383 (interactive)
384 (let ((b1 (current-buffer))
e6b72410 385 (b2 (or (2C-other)
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386 (read-buffer "Associate buffer: " (other-buffer)))))
387 (save-excursion
e6b72410 388 (setq 2C-mode nil)
72c0ae01 389 (set-buffer b2)
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390 (and (2C-other)
391 (not (eq b1 (2C-other)))
e8af40ee 392 (error "Buffer already associated with buffer `%s'"
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393 (buffer-name (2C-other))))
394 (setq b1 (and (assq '2C-window-width (buffer-local-variables))
395 2C-window-width)))
72c0ae01 396 ; if other buffer has a local width, adjust here too
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397 (if b1 (setq 2C-window-width (- (frame-width) b1)))
398 (2C-two-columns b2)))
399
400
72c0ae01 401
6f5191a2 402;;;###autoload
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403(defun 2C-split (arg)
404 "Split a two-column text at point, into two buffers in two-column minor mode.
405Point becomes the local value of `2C-window-width'. Only lines that
406have the ARG same preceding characters at that column get split. The
407ARG preceding characters without any leading whitespace become the local
408value for `2C-separator'. This way lines that continue across both
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409columns remain untouched in the first buffer.
410
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411This function can be used with a prototype line, to set up things. You
412write the first line of each column and then split that line. E.g.:
72c0ae01 413
e6b72410 414First column's text sSs Second column's text
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415 \\___/\\
416 / \\
e6b72410 417 5 character Separator You type M-5 \\[2C-split] with the point here.
72c0ae01 418
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419\(See \\[describe-mode] .)"
420 (interactive "*p")
421 (and (2C-other)
72c0ae01 422 (if (y-or-n-p (concat "Overwrite associated buffer `"
e6b72410 423 (buffer-name (2C-other))
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424 "'? "))
425 (save-excursion
e6b72410 426 (set-buffer (2C-other))
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427 (erase-buffer))
428 (signal 'quit nil)))
429 (let ((point (point))
430 ; make next-line always come back to same column
431 (goal-column (current-column))
432 ; a counter for empty lines in other buffer
433 (n (1- (count-lines (point-min) (point))))
434 chars other)
435 (save-excursion
436 (backward-char arg)
437 (setq chars (buffer-substring (point) point))
438 (skip-chars-forward " \t" point)
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439 (make-local-variable '2C-separator)
440 (setq 2C-separator (buffer-substring (point) point)
441 2C-window-width (current-column)))
442 (2C-two-columns)
443 (setq other (2C-other))
444 ; now we're ready to actually split
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445 (save-excursion
446 (while (not (eobp))
447 (if (not (and (= (current-column) goal-column)
448 (string= chars
449 (buffer-substring (point)
450 (save-excursion
451 (backward-char arg)
452 (point))))))
453 (setq n (1+ n))
454 (setq point (point))
455 (backward-char arg)
456 (skip-chars-backward " \t")
457 (delete-region point (point))
458 (setq point (point))
459 (insert-char ?\n n)
460 (append-to-buffer other point (progn (end-of-line)
461 (if (eobp)
462 (point)
463 (1+ (point)))))
464 (delete-region point (point))
465 (setq n 0))
466 (next-line 1)))))
467
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468
469
470
471(defun 2C-dissociate ()
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472 "Turn off two-column minor mode in current and associated buffer.
473If the associated buffer is unmodified and empty, it is killed."
474 (interactive)
475 (let ((buffer (current-buffer)))
476 (save-excursion
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477 (and (2C-other)
478 (set-buffer (2C-other))
479 (or (not (2C-other))
480 (eq buffer (2C-other)))
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481 (if (and (not (buffer-modified-p))
482 (eobp) (bobp))
483 (kill-buffer nil)
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484 (kill-local-variable '2C-mode)
485 (kill-local-variable '2C-window-width)
486 (kill-local-variable '2C-separator)
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487 (kill-local-variable 'mode-line-format)
488 (kill-local-variable 'fill-column))))
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489 (kill-local-variable '2C-mode)
490 (kill-local-variable '2C-window-width)
491 (kill-local-variable '2C-separator)
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492 (kill-local-variable 'mode-line-format)
493 (kill-local-variable 'fill-column)))
494
495
e6b72410 496
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497;; this doesn't use yank-rectangle, so that the first column can
498;; contain long lines
e6b72410 499(defun 2C-merge ()
72c0ae01 500 "Merges the associated buffer with the current buffer.
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501They get merged at the column, which is the value of `2C-window-width',
502i.e. usually at the vertical window separator. This separator gets
503replaced with white space. Beyond that the value of `2C-separator' gets
504inserted on merged lines. The two columns are thus pasted side by side,
505in a single text. If the other buffer is not displayed to the left of
506this one, then this one becomes the left column.
507
508If you want `2C-separator' on empty lines in the second column,
72c0ae01 509you should put just one space in them. In the final result, you can strip
eaae8106 510off trailing spaces with \\[delete-trailing-whitespace]."
72c0ae01 511 (interactive)
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512 (and (> (car (window-edges)) 0) ; not touching left edge of screen
513 (eq (window-buffer (previous-window))
8fe9ecef 514 (2C-other t))
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515 (other-window -1))
516 (save-excursion
517 (let ((b1 (current-buffer))
8fe9ecef 518 (b2 (2C-other t))
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519 string)
520 (goto-char (point-min))
521 (set-buffer b2)
522 (goto-char (point-min))
523 (while (not (eobp))
524 (setq string (buffer-substring (point)
525 (progn (end-of-line) (point))))
526 (or (eobp)
527 (forward-char)) ; next line
528 (set-buffer b1)
529 (if (string= string "")
530 ()
531 (end-of-line)
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532 (indent-to-column 2C-window-width)
533 (insert 2C-separator string))
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534 (next-line 1) ; add one if necessary
535 (set-buffer b2))))
3bcbd523 536 (if (< (window-width) (frame-width))
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537 (enlarge-window 99999 t)))
538\f
539;;;;; utility functions ;;;;;
540
e6b72410 541(defun 2C-associated-buffer ()
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542 "Switch to associated buffer."
543 (interactive)
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544 (let ((line (+ (count-lines (point-min) (point))
545 (if (bolp) 1 0)))
546 (col (if (eolp) (if (bolp) 0) (current-column))))
547 (if (get-buffer-window (2C-other t))
548 (select-window (get-buffer-window (2C-other)))
549 (switch-to-buffer (2C-other)))
550 (newline (goto-line line))
551 (if col
552 (move-to-column col)
553 (end-of-line 1))))
554
555(defun 2C-newline (arg)
556 "Insert ARG newlines in both buffers."
557 (interactive "P")
558 (save-window-excursion
559 (2C-associated-buffer)
560 (newline arg))
561 (newline arg))
72c0ae01 562
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563(defun 2C-toggle-autoscroll (arg)
564 "Toggle autoscrolling, or set it iff prefix ARG is non-nil and positive.
565When autoscrolling is turned on, this also realigns the two buffers."
72c0ae01 566 (interactive "P")
8fe9ecef 567 ;(sit-for 0)
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568 (setq 2C-autoscroll-start (window-start))
569 (if (setq 2C-autoscroll (if arg
570 (>= (prefix-numeric-value arg) 0)
571 (not 2C-autoscroll)))
572 (select-window
573 (prog1 (selected-window)
574 (message "Autoscrolling is on.")
e6b72410 575 (setq arg (count-lines (point-min) (window-start)))
8fe9ecef 576 (if (get-buffer-window (2C-other t))
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577 (progn
578 (select-window (get-buffer-window (2C-other)))
579 (setq arg (- arg (count-lines (point-min) (window-start))))
580 ;; make sure that other buffer has enough lines
581 (save-excursion
582 (insert-char ?\n
583 (- arg (count-lines (window-start)
584 (goto-char (point-max)))
585 -1)))
586 (scroll-up arg)))))
587 (message "Autoscrolling is off.")))
588
589
590
591(defun 2C-autoscroll ()
592 (if 2C-autoscroll
593 ;; catch a mouse scroll on non-selected scrollbar
594 (select-window
595 (prog1 (selected-window)
596 (and (consp last-command-char)
597 (not (eq (selected-window)
598 (car (car (cdr last-command-char)))))
599 (select-window (car (car (cdr last-command-char)))))
600 ;; In some cases scrolling causes an error, but post-command-hook
601 ;; shouldn't, and should always stay in the original window
602 (condition-case ()
603 (and (or 2C-autoscroll-start (2C-toggle-autoscroll t) nil)
604 (/= (window-start) 2C-autoscroll-start)
605 (2C-other)
606 (get-buffer-window (2C-other))
607 (let ((lines (count-lines (window-start)
608 2C-autoscroll-start)))
609 (if (< (window-start) 2C-autoscroll-start)
610 (setq lines (- lines)))
611 (setq 2C-autoscroll-start (window-start))
612 (select-window (get-buffer-window (2C-other)))
613 ;; make sure that other buffer has enough lines
614 (save-excursion
615 (insert-char
616 ?\n (- lines (count-lines (window-start)
617 (goto-char (point-max)))
618 -1)))
619 (scroll-up lines)
620 (setq 2C-autoscroll-start (window-start))))
621 (error))))))
622
623
72c0ae01 624
30a7d33c 625(defun 2C-enlarge-window-horizontally (arg)
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626 "Make current window ARG columns wider."
627 (interactive "p")
628 (enlarge-window arg t)
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629 (and (2C-other)
630 (setq 2C-window-width (+ 2C-window-width arg))
631 (set-buffer (2C-other))
632 (setq 2C-window-width (- 2C-window-width arg))))
72c0ae01 633
30a7d33c 634(defun 2C-shrink-window-horizontally (arg)
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635 "Make current window ARG columns narrower."
636 (interactive "p")
30a7d33c 637 (2C-enlarge-window-horizontally (- arg)))
72c0ae01 638
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639
640
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641(provide 'two-column)
642
ab5796a9 643;;; arch-tag: 2021b5ab-d3a4-4a8c-a21c-1936b0f9e6b1
72c0ae01 644;;; two-column.el ends here