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[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 Free Software Foundation, Inc.
4
3e910376 5;; Author: Daniel Pfeiffer <occitan@esperanto.org>
e6b72410 6;; Adapted-By: ESR, Daniel Pfeiffer
6228c05b 7;; Keywords: wp
e6b72410 8
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9;; This file is part of GNU Emacs.
10
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11;; Esperanto: English:
12
13;; ^Ci dosiero estas ero de GNU Emacs. This file is part of GNU Emacs.
14
15;; GNU Emacs estas libera programaro; GNU Emacs is free software; you can
16;; vi povas disdoni ^gin kaj/a^u modifi redistribute it and/or modify it
17;; ^gin sub la kondi^coj de la GNU under the terms of the GNU General
18;; ^Generala Publika Licenco kiel pub- Public License as published by the
19;; likigita far la Liberprogramara Fon- Free Software Foundation; either
20;; da^jo; a^u eldono 2a, a^u (la^u via version 2, or (at your option) any
21;; elekto) ajna posta eldono. later version.
22
23;; GNU Emacs estas disdonata en la GNU Emacs is distributed in the hope
24;; espero ke ^gi estos utila, sed SEN that it will be useful, but WITHOUT
25;; IA GARANTIO; sen e^c la implicita ANY WARRANTY; without even the
26;; garantio de VENDEBLECO a^u PRETECO implied warranty of MERCHANTABILITY
27;; POR DETERMINITA CELO. Vidu la GNU or FITNESS FOR A PARTICULAR PURPOSE.
28;; ^Generala Publika Licenco por plenaj See the GNU General Public License
29;; detaloj. for more details.
30
31;; Vi devus ricevinti kopion de la GNU You should have received a copy of
32;; ^Generala Publika Licenco kune kun the GNU General Public License along
33;; GNU Emacs; vidu la dosieron COPYING. with GNU Emacs; see the file
34;; Alikaze skribu al la COPYING. If not, write to the
35
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36;; Free Software Foundation, 59 Temple Place - Suite 330
37;; Boston, MA 02111-1307, USA.
e6b72410 38
e8af40ee 39;;; Commentary:
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40
41;;; Komentario: Commentary:
42
43;; Tiu programaro ebligas vin redakti This package gives you the ability
44;; dukolumnan tekston. to edit text in a two-column format.
45
46
47;; Vi havas tri eblecojn por eki tiun You have three ways to start up this
48;; mal^cefan modalon. ^Ciu donas al vi minor mode. Each gives you a
49;; horizontale disigatan fenestron, si- horizontally split window similar to
50;; milan al fina apareco de via teksto: the final outcome of your text:
51
52
53;; f2 2 asocias novan bufron nomatan associates a new buffer called
54;; C-x 6 2 same, sed kun 2C/ anta^u. the same, but with 2C/
55;; prepended.
56
57;; f2 b asocias alian bufron. Vi povas associates another buffer.
58;; C-x 6 b anka^u asocii dataron, se vi This can be used to associate a
59;; ^jus anta^ue faris C-x C-f. file if you just did C-x C-f.
60
61;; f2 s disigas jam dukolumnan tekston splits a two-column text into
62;; C-x 6 s en du bufroj ekde la nuna two buffers from the current
63;; linio, kaj je la nuna kolumno. line and at the current column.
64;; La anta^uaj signoj (ofte The preceding characters (often
65;; tabeligilo a^u |) estas la tab or |) are the column
66;; kolumna disiganto. Linioj kiuj separator. Lines that don't
67;; ne enhavas ilin ne estas have them won't be separated.
68;; disigitaj. Kiel la kvara kaj Like the fourth and fifth line
69;; la kvina linio se vi disigas if you split this file from
70;; ^ci dataron ekde la unua angla the first english word.
71;; vorto.
72
73;; Se vi volas meti longajn liniojn If you include long lines, i.e which
74;; (ekz. programerojn) en la kunigotan will span both columns (eg. source
75;; tekston, ili devas esti en la code), they should be in what will
76;; estonte unua kolumno. La alia devas be the first column, with the
77;; havi vakajn linion apud ili. associated buffer having empty lines
78;; next to them.
79
80;; Averto: en Emacs kiam vi ^san^gas la Attention: in Emacs when you change
81;; ^cefan modalon, la mal^cefaj modaloj the major mode, the minor modes are
82;; estas anka^u elmemorigitaj. Tiu- also purged from memory. In that
83;; okaze vi devas religi la du bufrojn case you must reassociate the two
84;; per iu C-x 6-ordono, ekz. C-x 6 b. buffers with any C-x 6-command, e.g.
85;; C-x 6 b.
86
87;; Kiam vi estos kontenta de la When you have edited both buffers to
88;; rezulto, vi kunmetos la du kolumnojn your content, you merge them with
89;; per C-x 6 1. Se vi poste vidas C-x 6 1. If you then see a problem,
90;; problemon, vi neniigu la kunmeton you undo the merge with C-x u and
91;; per C-x u kaj plue modifu la du continue to edit the two buffers.
92;; bufrojn. Kiam vi ne plu volas tajpi When you no longer want to edit in
93;; dukolumne, vi eliru el la mal^cefa two columns, you turn off the minor
94;; modalo per C-x 6 d. mode with C-x 6 d.
95
96
97;; Aldone al dukolumna redaktado, ek- In addition to two-column editing of
98;; zemple por skribi dulingvan tekston text, for example for writing a
99;; flank-al-flanke kiel ^ci tiu, aliaj bilingual text side-by-side as shown
100;; interesaj uzoj trovitas por tiu mal- here, other interesting uses have
101;; ^cefa modalo: been found for this minor mode:
102
103;; Vi povas disigi la kolumnojn per {+} You can separate the columns with
104;; ajna pla^ca ^ceno starigante {+} any string that pleases you, by
105;; `2C-separator'. Ekzemple "{+} " {+} setting `2C-separator'. For example
106;; por amuzi^gi. f2 s a^u C-x 6 s {+} "{+} " if you'd like to have fun.
107;; traktas tiujn kun prefiksa {+} f2 s or C-x 6 s handles these with a
108;; argumento kiu signifas la longon {+} prefix argument that means the
109;; de tia ^ceno. {+} desired length of such a string.
110
111
112;; Programistoj eble ^satus la eblecon Programmers might like the ability
113;; forspliti la komentarian kolumnon de to split off the comment column of a
114;; dosiero kiel la sekvanta. Vi povas file that looks like the following.
115;; rearan^gigi la paragrafon. La pro- You can fill-paragraph the comment.
116;; blemo estas ke koda^jo tuj lar- The problem is, code quickly gets
117;; ^gi^gas, tiel ke vi bezonas pli rather wide, so you need to use a
118;; mallar^gan komentarian kolumnon. narrower comment column. Code lines
119;; Koda^jaj linioj tra `comment-column' that reach beyond `comment-column'
120;; ne problemas, krom ke vi ne vidos are no problem, except that you
121;; iliajn finojn dum redaktado. won't see their end during editing.
122
123
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124;; BEGIN -- This is just some meaningless
125;; FOR i IN 1..10 LOOP -- code in Ada, that runs foobar
e6b72410 126;; foobar( i ); -- once for each argument from one
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127;; END LOOP; -- to ten, and then we're already
128;; END; -- through with it.
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129
130;; Pli bone ankora^u, vi povas pozici- Better yet, you can put the point
131;; i^gi anta^u "This", tajpi M-3 f2 s before "This", type M-3 f2 s
132;; kiu igas "-- " la separigilon inter which makes "-- " the separator
133;; senkomentaria Ada bufro kaj nur- between a no-comments Ada buffer,
134;; teksta komentaria bufro. Kiam vi and a plain text comment buffer.
135;; denove kuni^gos ilin, ^ciu nevaka When you put them back together,
136;; linio de l' dua kolumno denove every non-empty line of the 2nd
137;; anta^uhavos "-- ". column will again be preceded by
138;; "-- ".
139
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140
141;;; Code:
142\f
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143
144;; Lucid patch
145(or (fboundp 'frame-width)
146 (fset 'frame-width 'screen-width))
147
148
3bcbd523 149;;;;; Set up keymap ;;;;;
72c0ae01 150
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151(defvar 2C-mode-map
152 (let ((map (make-sparse-keymap)))
153 (define-key map "2" '2C-two-columns)
154 (define-key map [f2] '2C-two-columns)
155 (define-key map "b" '2C-associate-buffer)
156 (define-key map "s" '2C-split)
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157 map)
158 "Keymap for commands for setting up two-column mode.")
159
160
161
162;;;###autoload (autoload '2C-command "two-column" () t 'keymap)
163(fset '2C-command 2C-mode-map)
72c0ae01 164
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165;; This one is for historical reasons and simple keyboards, it is not
166;; at all mnemonic. All usual sequences containing 2 were used, and
167;; f2 could not be set up in a standard way under Emacs 18.
2c02e313 168;;;###autoload (global-set-key "\C-x6" '2C-command)
e6b72410 169
2c02e313 170;;;###autoload (global-set-key [f2] '2C-command)
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171
172
173(defvar 2C-minor-mode-map
174 (let ((map (make-sparse-keymap)))
175 (define-key map "1" '2C-merge)
176 (define-key map "d" '2C-dissociate)
177 (define-key map "o" '2C-associated-buffer)
8fe9ecef 178 (define-key map "\^m" '2C-newline)
e6b72410 179 (define-key map "|" '2C-toggle-autoscroll)
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180 (define-key map "{" '2C-shrink-window-horizontally)
181 (define-key map "}" '2C-enlarge-window-horizontally)
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182 map)
183 "Keymap for commands for use in two-column mode.")
184
185
186(setq minor-mode-map-alist
187 (cons (cons '2C-mode
188 (let ((map (make-sparse-keymap)))
189 (substitute-key-definition '2C-command 2C-minor-mode-map
190 map (current-global-map))
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191 (substitute-key-definition 'enlarge-window-horizontally
192 '2C-enlarge-window-horizontally
193 map (current-global-map))
194 (substitute-key-definition 'shrink-window-horizontally
195 '2C-shrink-window-horizontally
196 map (current-global-map))
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197 map))
198 minor-mode-map-alist))
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199\f
200;;;;; variable declarations ;;;;;
72c0ae01 201
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202(defgroup two-column nil
203 "Minor mode for editing of two-column text"
204 :prefix "2C-"
205 :group 'frames)
206
207
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208;; Markers seem to be the only buffer-id not affected by renaming a buffer.
209;; This nevertheless loses when a buffer is killed. The variable-name is
210;; required by `describe-mode'.
211(defvar 2C-mode nil
72c0ae01 212 "Marker to the associated buffer, if non-nil.")
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213(make-variable-buffer-local '2C-mode)
214(put '2C-mode 'permanent-local t)
215
216
217
218(setq minor-mode-alist (cons '(2C-mode " 2C") minor-mode-alist))
219
72c0ae01 220
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221
222;; rearranged, so that the pertinent info will show in 40 columns
ded3e3d8 223(defcustom 2C-mode-line-format
72c0ae01 224 '("-%*- %15b --" (-3 . "%p") "--%[(" mode-name
e6b72410 225 minor-mode-alist "%n" mode-line-process ")%]%-")
431328cc 226 "*Value of `mode-line-format' for a buffer in two-column minor mode."
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227 :type 'sexp
228 :group 'two-column)
72c0ae01 229
e6b72410 230
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231(defcustom 2C-other-buffer-hook 'text-mode
232 "*Hook run in new buffer when it is associated with current one."
233 :type 'function
234 :group 'two-column)
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235
236
ded3e3d8 237(defcustom 2C-separator ""
72c0ae01 238 "*A string inserted between the two columns when merging.
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239This gets set locally by \\[2C-split]."
240 :type 'string
241 :group 'two-column)
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242(put '2C-separator 'permanent-local t)
243
244
72c0ae01 245
ded3e3d8 246(defcustom 2C-window-width 40
72c0ae01 247 "*The width of the first column. (Must be at least `window-min-width')
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248This value is local for every buffer that sets it."
249 :type 'integer
250 :group 'two-column)
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251(make-variable-buffer-local '2C-window-width)
252(put '2C-window-width 'permanent-local t)
72c0ae01 253
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254
255
ded3e3d8 256(defcustom 2C-beyond-fill-column 4
72c0ae01 257 "*Base for calculating `fill-column' for a buffer in two-column minor mode.
e6b72410 258The value of `fill-column' becomes `2C-window-width' for this buffer
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259minus this value."
260 :type 'integer
261 :group 'two-column)
72c0ae01 262
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263
264
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265(defcustom 2C-autoscroll t
266 "If non-nil, Emacs attempts to keep the two column's buffers aligned."
267 :type 'boolean
268 :group 'two-column)
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269
270
271
272(defvar 2C-autoscroll-start nil)
273(make-variable-buffer-local '2C-autoscroll-start)
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274\f
275;;;;; base functions ;;;;;
276
e6b72410 277;; The access method for the other buffer. This tries to remedy against
72c0ae01 278;; lost local variables and lost buffers.
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279(defun 2C-other (&optional req)
280 (or (if 2C-mode
281 (or (prog1
282 (marker-buffer 2C-mode)
283 (setq mode-line-format 2C-mode-line-format))
284 ;; The associated buffer somehow got killed.
285 (progn
286 ;; The other variables may later be useful if the user
287 ;; reestablishes the association.
288 (kill-local-variable '2C-mode)
289 (kill-local-variable 'mode-line-format)
290 nil)))
e8af40ee 291 (if req (error "You must first set two-column minor mode"))))
72c0ae01 292
72c0ae01 293
72c0ae01 294
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295;; function for setting up two-column minor mode in a buffer associated
296;; with the buffer pointed to by the marker other.
297(defun 2C-mode (other)
298 "Minor mode for independently editing two columns.
299This is set up for two associated buffers by the three commands bound
300to \\[2C-two-columns] , \\[2C-associate-buffer] and \\[2C-split].
301Turning on two-column mode calls the value of the variable `2C-mode-hook',
302if that value is non-nil.
303
304These buffers can be edited separately, for example with `fill-paragraph'.
305If you want to disable parallel scrolling temporarily, use \\[2C-toggle-autoscroll] .
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306
307If you include long lines, i.e which will span both columns (eg.
308source code), they should be in what will be the first column, with
309the associated buffer having empty lines next to them.
310
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311Potential uses are writing bilingual texts, or editing the comments of a
312source code. See the file lisp/two-column.el for detailed examples.
313
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314You have the following commands at your disposal:
315
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316\\[2C-two-columns] Rearrange screen with current buffer first
317\\[2C-associate-buffer] Reassociate buffer after changing major mode
72c0ae01 318\\[shrink-window-horizontally], \\[enlarge-window-horizontally] Shrink, enlarge current column
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319\\[2C-associated-buffer] Switch to associated buffer at same point
320\\[2C-newline] Insert newline(s) in both buffers at same point
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321\\[2C-merge] Merge both buffers
322\\[2C-dissociate] Dissociate the two buffers
72c0ae01 323
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324These keybindings can be customized in your ~/.emacs by `2C-mode-map',
325`2C-minor-mode-map' and by binding `2C-command' to some prefix.
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326
327The appearance of the screen can be customized by the variables
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328`2C-window-width', `2C-beyond-fill-column', `2C-mode-line-format' and
329`truncate-partial-width-windows'."
5181be3a 330 (add-hook 'post-command-hook '2C-autoscroll nil t)
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331 (setq fill-column (- 2C-window-width
332 2C-beyond-fill-column)
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333 mode-line-format 2C-mode-line-format
334 2C-mode other)
335 (run-hooks '2C-mode-hook))
336
337
72c0ae01 338
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339;;;###autoload
340(defun 2C-two-columns (&optional buffer)
341 "Split current window vertically for two-column editing.
342When called the first time, associates a buffer with the current
343buffer in two-column minor mode (see \\[describe-mode] ).
344Runs `2C-other-buffer-hook' in the new buffer.
345When called again, restores the screen layout with the current buffer
17c3470e 346first and the associated buffer to its right."
72c0ae01 347 (interactive "P")
e6b72410 348 ;; first go to full width, so that we can certainly split into two windows
3bcbd523 349 (if (< (window-width) (frame-width))
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350 (enlarge-window 99999 t))
351 (split-window-horizontally
e6b72410 352 (max window-min-width (min 2C-window-width
3bcbd523 353 (- (frame-width) window-min-width))))
e6b72410 354 (if (2C-other)
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355 (progn
356 (other-window 1)
e6b72410 357 (switch-to-buffer (2C-other))
72c0ae01 358 (other-window -1)
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359 (if 2C-autoscroll
360 (2C-toggle-autoscroll t)))
361
362 (2C-mode (prog1 (point-marker)
363 (other-window 1)
364 (switch-to-buffer
365 (or buffer
8fe9ecef 366 (generate-new-buffer (concat "2C/" (buffer-name)))))
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367 (or buffer
368 (run-hooks '2C-other-buffer-hook))))
eaae8106 369
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370 (2C-mode (prog1 (point-marker)
371 (other-window -1)))))
372
373
72c0ae01 374
6f5191a2 375;;;###autoload
e6b72410 376(defun 2C-associate-buffer ()
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377 "Associate another buffer with this one in two-column minor mode.
378Can also be used to associate a just previously visited file, by
379accepting the proposed default buffer.
380
e6b72410 381\(See \\[describe-mode] .)"
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382 (interactive)
383 (let ((b1 (current-buffer))
e6b72410 384 (b2 (or (2C-other)
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385 (read-buffer "Associate buffer: " (other-buffer)))))
386 (save-excursion
e6b72410 387 (setq 2C-mode nil)
72c0ae01 388 (set-buffer b2)
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389 (and (2C-other)
390 (not (eq b1 (2C-other)))
e8af40ee 391 (error "Buffer already associated with buffer `%s'"
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392 (buffer-name (2C-other))))
393 (setq b1 (and (assq '2C-window-width (buffer-local-variables))
394 2C-window-width)))
72c0ae01 395 ; if other buffer has a local width, adjust here too
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396 (if b1 (setq 2C-window-width (- (frame-width) b1)))
397 (2C-two-columns b2)))
398
399
72c0ae01 400
6f5191a2 401;;;###autoload
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402(defun 2C-split (arg)
403 "Split a two-column text at point, into two buffers in two-column minor mode.
404Point becomes the local value of `2C-window-width'. Only lines that
405have the ARG same preceding characters at that column get split. The
406ARG preceding characters without any leading whitespace become the local
407value for `2C-separator'. This way lines that continue across both
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408columns remain untouched in the first buffer.
409
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410This function can be used with a prototype line, to set up things. You
411write the first line of each column and then split that line. E.g.:
72c0ae01 412
e6b72410 413First column's text sSs Second column's text
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414 \\___/\\
415 / \\
e6b72410 416 5 character Separator You type M-5 \\[2C-split] with the point here.
72c0ae01 417
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418\(See \\[describe-mode] .)"
419 (interactive "*p")
420 (and (2C-other)
72c0ae01 421 (if (y-or-n-p (concat "Overwrite associated buffer `"
e6b72410 422 (buffer-name (2C-other))
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423 "'? "))
424 (save-excursion
e6b72410 425 (set-buffer (2C-other))
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426 (erase-buffer))
427 (signal 'quit nil)))
428 (let ((point (point))
429 ; make next-line always come back to same column
430 (goal-column (current-column))
431 ; a counter for empty lines in other buffer
432 (n (1- (count-lines (point-min) (point))))
433 chars other)
434 (save-excursion
435 (backward-char arg)
436 (setq chars (buffer-substring (point) point))
437 (skip-chars-forward " \t" point)
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438 (make-local-variable '2C-separator)
439 (setq 2C-separator (buffer-substring (point) point)
440 2C-window-width (current-column)))
441 (2C-two-columns)
442 (setq other (2C-other))
443 ; now we're ready to actually split
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444 (save-excursion
445 (while (not (eobp))
446 (if (not (and (= (current-column) goal-column)
447 (string= chars
448 (buffer-substring (point)
449 (save-excursion
450 (backward-char arg)
451 (point))))))
452 (setq n (1+ n))
453 (setq point (point))
454 (backward-char arg)
455 (skip-chars-backward " \t")
456 (delete-region point (point))
457 (setq point (point))
458 (insert-char ?\n n)
459 (append-to-buffer other point (progn (end-of-line)
460 (if (eobp)
461 (point)
462 (1+ (point)))))
463 (delete-region point (point))
464 (setq n 0))
465 (next-line 1)))))
466
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467
468
469
470(defun 2C-dissociate ()
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471 "Turn off two-column minor mode in current and associated buffer.
472If the associated buffer is unmodified and empty, it is killed."
473 (interactive)
474 (let ((buffer (current-buffer)))
475 (save-excursion
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476 (and (2C-other)
477 (set-buffer (2C-other))
478 (or (not (2C-other))
479 (eq buffer (2C-other)))
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480 (if (and (not (buffer-modified-p))
481 (eobp) (bobp))
482 (kill-buffer nil)
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483 (kill-local-variable '2C-mode)
484 (kill-local-variable '2C-window-width)
485 (kill-local-variable '2C-separator)
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486 (kill-local-variable 'mode-line-format)
487 (kill-local-variable 'fill-column))))
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488 (kill-local-variable '2C-mode)
489 (kill-local-variable '2C-window-width)
490 (kill-local-variable '2C-separator)
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491 (kill-local-variable 'mode-line-format)
492 (kill-local-variable 'fill-column)))
493
494
e6b72410 495
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496;; this doesn't use yank-rectangle, so that the first column can
497;; contain long lines
e6b72410 498(defun 2C-merge ()
72c0ae01 499 "Merges the associated buffer with the current buffer.
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500They get merged at the column, which is the value of `2C-window-width',
501i.e. usually at the vertical window separator. This separator gets
502replaced with white space. Beyond that the value of `2C-separator' gets
503inserted on merged lines. The two columns are thus pasted side by side,
504in a single text. If the other buffer is not displayed to the left of
505this one, then this one becomes the left column.
506
507If you want `2C-separator' on empty lines in the second column,
72c0ae01 508you should put just one space in them. In the final result, you can strip
eaae8106 509off trailing spaces with \\[delete-trailing-whitespace]."
72c0ae01 510 (interactive)
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511 (and (> (car (window-edges)) 0) ; not touching left edge of screen
512 (eq (window-buffer (previous-window))
8fe9ecef 513 (2C-other t))
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514 (other-window -1))
515 (save-excursion
516 (let ((b1 (current-buffer))
8fe9ecef 517 (b2 (2C-other t))
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518 string)
519 (goto-char (point-min))
520 (set-buffer b2)
521 (goto-char (point-min))
522 (while (not (eobp))
523 (setq string (buffer-substring (point)
524 (progn (end-of-line) (point))))
525 (or (eobp)
526 (forward-char)) ; next line
527 (set-buffer b1)
528 (if (string= string "")
529 ()
530 (end-of-line)
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531 (indent-to-column 2C-window-width)
532 (insert 2C-separator string))
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533 (next-line 1) ; add one if necessary
534 (set-buffer b2))))
3bcbd523 535 (if (< (window-width) (frame-width))
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536 (enlarge-window 99999 t)))
537\f
538;;;;; utility functions ;;;;;
539
e6b72410 540(defun 2C-associated-buffer ()
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541 "Switch to associated buffer."
542 (interactive)
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543 (let ((line (+ (count-lines (point-min) (point))
544 (if (bolp) 1 0)))
545 (col (if (eolp) (if (bolp) 0) (current-column))))
546 (if (get-buffer-window (2C-other t))
547 (select-window (get-buffer-window (2C-other)))
548 (switch-to-buffer (2C-other)))
549 (newline (goto-line line))
550 (if col
551 (move-to-column col)
552 (end-of-line 1))))
553
554(defun 2C-newline (arg)
555 "Insert ARG newlines in both buffers."
556 (interactive "P")
557 (save-window-excursion
558 (2C-associated-buffer)
559 (newline arg))
560 (newline arg))
72c0ae01 561
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562(defun 2C-toggle-autoscroll (arg)
563 "Toggle autoscrolling, or set it iff prefix ARG is non-nil and positive.
564When autoscrolling is turned on, this also realigns the two buffers."
72c0ae01 565 (interactive "P")
8fe9ecef 566 ;(sit-for 0)
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567 (setq 2C-autoscroll-start (window-start))
568 (if (setq 2C-autoscroll (if arg
569 (>= (prefix-numeric-value arg) 0)
570 (not 2C-autoscroll)))
571 (select-window
572 (prog1 (selected-window)
573 (message "Autoscrolling is on.")
e6b72410 574 (setq arg (count-lines (point-min) (window-start)))
8fe9ecef 575 (if (get-buffer-window (2C-other t))
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576 (progn
577 (select-window (get-buffer-window (2C-other)))
578 (setq arg (- arg (count-lines (point-min) (window-start))))
579 ;; make sure that other buffer has enough lines
580 (save-excursion
581 (insert-char ?\n
582 (- arg (count-lines (window-start)
583 (goto-char (point-max)))
584 -1)))
585 (scroll-up arg)))))
586 (message "Autoscrolling is off.")))
587
588
589
590(defun 2C-autoscroll ()
591 (if 2C-autoscroll
592 ;; catch a mouse scroll on non-selected scrollbar
593 (select-window
594 (prog1 (selected-window)
595 (and (consp last-command-char)
596 (not (eq (selected-window)
597 (car (car (cdr last-command-char)))))
598 (select-window (car (car (cdr last-command-char)))))
599 ;; In some cases scrolling causes an error, but post-command-hook
600 ;; shouldn't, and should always stay in the original window
601 (condition-case ()
602 (and (or 2C-autoscroll-start (2C-toggle-autoscroll t) nil)
603 (/= (window-start) 2C-autoscroll-start)
604 (2C-other)
605 (get-buffer-window (2C-other))
606 (let ((lines (count-lines (window-start)
607 2C-autoscroll-start)))
608 (if (< (window-start) 2C-autoscroll-start)
609 (setq lines (- lines)))
610 (setq 2C-autoscroll-start (window-start))
611 (select-window (get-buffer-window (2C-other)))
612 ;; make sure that other buffer has enough lines
613 (save-excursion
614 (insert-char
615 ?\n (- lines (count-lines (window-start)
616 (goto-char (point-max)))
617 -1)))
618 (scroll-up lines)
619 (setq 2C-autoscroll-start (window-start))))
620 (error))))))
621
622
72c0ae01 623
30a7d33c 624(defun 2C-enlarge-window-horizontally (arg)
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625 "Make current window ARG columns wider."
626 (interactive "p")
627 (enlarge-window arg t)
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628 (and (2C-other)
629 (setq 2C-window-width (+ 2C-window-width arg))
630 (set-buffer (2C-other))
631 (setq 2C-window-width (- 2C-window-width arg))))
72c0ae01 632
30a7d33c 633(defun 2C-shrink-window-horizontally (arg)
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634 "Make current window ARG columns narrower."
635 (interactive "p")
30a7d33c 636 (2C-enlarge-window-horizontally (- arg)))
72c0ae01 637
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638
639
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640(provide 'two-column)
641
72c0ae01 642;;; two-column.el ends here