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60370d40 | 1 | ;;; composite.el --- support character composition |
c674f351 KH |
2 | |
3 | ;; Copyright (C) 1999 Electrotechnical Laboratory, JAPAN. | |
4 | ;; Licensed to the Free Software Foundation. | |
5 | ||
6 | ;; Keywords: mule, multilingual, character composition | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
11 | ;; it under the terms of the GNU General Public License as published by | |
12 | ;; the Free Software Foundation; either version 2, or (at your option) | |
13 | ;; any later version. | |
14 | ||
15 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | ;; GNU General Public License for more details. | |
19 | ||
20 | ;; You should have received a copy of the GNU General Public License | |
21 | ;; along with GNU Emacs; see the file COPYING. If not, write to the | |
22 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | ;; Boston, MA 02111-1307, USA. | |
24 | ||
60370d40 PJ |
25 | ;;; Commentary: |
26 | ||
c674f351 KH |
27 | ;;; Code: |
28 | ||
c674f351 KH |
29 | (defconst reference-point-alist |
30 | '((tl . 0) (tc . 1) (tr . 2) | |
31 | (Bl . 3) (Bc . 4) (Br . 5) | |
32 | (bl . 6) (bc . 7) (br . 8) | |
33 | (cl . 9) (cc . 10) (cr . 11) | |
34 | (top-left . 0) (top-center . 1) (top-right . 2) | |
35 | (base-left . 3) (base-center . 4) (base-right . 5) | |
36 | (bottom-left . 6) (bottom-center . 7) (bottom-right . 8) | |
37 | (center-left . 9) (center-center . 10) (center-right . 11) | |
38 | ;; For backward compatibility... | |
39 | (ml . 3) (mc . 10) (mr . 5) | |
40 | (mid-left . 3) (mid-center . 10) (mid-right . 5)) | |
41 | "Alist of symbols vs integer codes of glyph reference points. | |
42 | A glyph reference point symbol is to be used to specify a composition | |
1d1af02d | 43 | rule in COMPONENTS argument to such functions as `compose-region'. |
c674f351 KH |
44 | |
45 | Meanings of glyph reference point codes are as follows: | |
46 | ||
47 | 0----1----2 <---- ascent 0:tl or top-left | |
48 | | | 1:tc or top-center | |
49 | | | 2:tr or top-right | |
50 | | | 3:Bl or base-left 9:cl or center-left | |
51 | 9 10 11 <---- center 4:Bc or base-center 10:cc or center-center | |
52 | | | 5:Br or base-right 11:cr or center-right | |
53 | --3----4----5-- <-- baseline 6:bl or bottom-left | |
54 | | | 7:bc or bottom-center | |
55 | 6----7----8 <---- descent 8:br or bottom-right | |
56 | ||
57 | Glyph reference point symbols are to be used to specify composition | |
58 | rule of the form \(GLOBAL-REF-POINT . NEW-REF-POINT), where | |
59 | GLOBAL-REF-POINT is a reference point in the overall glyphs already | |
60 | composed, and NEW-REF-POINT is a reference point in the new glyph to | |
61 | be added. | |
62 | ||
63 | For instance, if GLOBAL-REF-POINT is `br' (bottom-right) and | |
8f625692 | 64 | NEW-REF-POINT is `tc' (top-center), the overall glyph is updated as |
c674f351 KH |
65 | follows (the point `*' corresponds to both reference points): |
66 | ||
67 | +-------+--+ <--- new ascent | |
68 | | | | | |
69 | | global| | | |
70 | | glyph | | | |
71 | -- | | |-- <--- baseline \(doesn't change) | |
72 | +----+--*--+ | |
73 | | | new | | |
74 | | |glyph| | |
75 | +----+-----+ <--- new descent | |
9c87e5c4 KH |
76 | |
77 | A composition rule may have the form \(GLOBAL-REF-POINT | |
78 | NEW-REF-POINT XOFF YOFF), where XOFF and YOFF specifies how much | |
79 | to shift NEW-REF-POINT from GLOBAL-REF-POINT. In this case, XOFF | |
80 | and YOFF are integers in the range -100..100 representing the | |
81 | shifting percentage against the font size.") | |
c674f351 KH |
82 | |
83 | ;; Encode composition rule RULE into an integer value. RULE is a cons | |
84 | ;; of global and new reference point symbols. | |
85 | ;; This must be compatible with C macro COMPOSITION_ENCODE_RULE | |
86 | ;; defined in composite.h. | |
87 | ||
88 | (defun encode-composition-rule (rule) | |
89 | (if (and (integerp rule) (< rule 144)) | |
90 | ;; Already encoded. | |
91 | rule | |
9c87e5c4 KH |
92 | (if (consp rule) |
93 | (let ((gref (car rule)) | |
94 | (nref (cdr rule)) | |
95 | xoff yoff) | |
96 | (if (consp nref) ; (GREF NREF XOFF YOFF) | |
97 | (progn | |
98 | (setq xoff (nth 1 nref) | |
99 | yoff (nth 2 nref) | |
100 | nref (car nref)) | |
101 | (or (and (>= xoff -100) (<= xoff 100) | |
102 | (>= yoff -100) (<= yoff 100)) | |
103 | (error "Invalid compostion rule: %s" rule)) | |
104 | (setq xoff (+ xoff 128) yoff (+ yoff 128))) | |
105 | ;; (GREF . NREF) | |
106 | (setq xoff 0 yoff 0)) | |
107 | (or (integerp gref) | |
108 | (setq gref (cdr (assq gref reference-point-alist)))) | |
109 | (or (integerp nref) | |
110 | (setq nref (cdr (assq nref reference-point-alist)))) | |
111 | (or (and (>= gref 0) (< gref 12) (>= nref 0) (< nref 12)) | |
112 | (error "Invalid composition rule: %S" rule)) | |
113 | (logior (lsh xoff 16) (lsh yoff 8) (+ (* gref 12) nref))) | |
114 | (error "Invalid composition rule: %S" rule)))) | |
c674f351 KH |
115 | |
116 | ;; Decode encoded composition rule RULE-CODE. The value is a cons of | |
117 | ;; global and new reference point symbols. | |
118 | ;; This must be compatible with C macro COMPOSITION_DECODE_RULE | |
119 | ;; defined in composite.h. | |
120 | ||
121 | (defun decode-composition-rule (rule-code) | |
9c87e5c4 | 122 | (or (and (natnump rule-code) (< rule-code #x1000000)) |
c674f351 | 123 | (error "Invalid encoded composition rule: %S" rule-code)) |
9c87e5c4 KH |
124 | (let ((xoff (lsh rule-code -16)) |
125 | (yoff (logand (lsh rule-code -8) #xFF)) | |
126 | gref nref) | |
127 | (setq rule-code (logand rule-code #xFF) | |
128 | gref (car (rassq (/ rule-code 12) reference-point-alist)) | |
129 | nref (car (rassq (% rule-code 12) reference-point-alist))) | |
c674f351 KH |
130 | (or (and gref (symbolp gref) nref (symbolp nref)) |
131 | (error "Invalid composition rule code: %S" rule-code)) | |
9c87e5c4 KH |
132 | (if (and (= xoff 0) (= yoff 0)) |
133 | (cons gref nref) | |
134 | (setq xoff (- xoff 128) yoff (- yoff 128)) | |
135 | (list gref xoff yoff nref)))) | |
c674f351 KH |
136 | |
137 | ;; Encode composition rules in composition components COMPONENTS. The | |
138 | ;; value is a copy of COMPONENTS, where composition rules (cons of | |
139 | ;; global and new glyph reference point symbols) are replaced with | |
140 | ;; encoded composition rules. Optional 2nd argument NOCOPY non-nil | |
141 | ;; means don't make a copy but modify COMPONENTS directly. | |
142 | ||
143 | (defun encode-composition-components (components &optional nocopy) | |
144 | (or nocopy | |
145 | (setq components (copy-sequence components))) | |
146 | (if (vectorp components) | |
147 | (let ((len (length components)) | |
148 | (i 1)) | |
149 | (while (< i len) | |
150 | (aset components i | |
151 | (encode-composition-rule (aref components i))) | |
152 | (setq i (+ i 2)))) | |
153 | (let ((tail (cdr components))) | |
154 | (while tail | |
155 | (setcar tail | |
156 | (encode-composition-rule (car tail))) | |
157 | (setq tail (nthcdr 2 tail))))) | |
158 | components) | |
159 | ||
160 | ;; Decode composition rule codes in composition components COMPONENTS. | |
161 | ;; The value is a copy of COMPONENTS, where composition rule codes are | |
162 | ;; replaced with composition rules (cons of global and new glyph | |
163 | ;; reference point symbols). Optional 2nd argument NOCOPY non-nil | |
164 | ;; means don't make a copy but modify COMPONENTS directly. | |
165 | ;; It is assumed that COMPONENTS is a vector and is for rule-base | |
166 | ;; composition, thus (2N+1)th elements are rule codes. | |
167 | ||
168 | (defun decode-composition-components (components &optional nocopy) | |
169 | (or nocopy | |
170 | (setq components (copy-sequence components))) | |
171 | (let ((len (length components)) | |
172 | (i 1)) | |
173 | (while (< i len) | |
174 | (aset components i | |
175 | (decode-composition-rule (aref components i))) | |
176 | (setq i (+ i 2)))) | |
177 | components) | |
178 | ||
c674f351 KH |
179 | (defun compose-region (start end &optional components modification-func) |
180 | "Compose characters in the current region. | |
181 | ||
c9f60860 KH |
182 | Characters are composed relatively, i.e. composed by overstricking or |
183 | stacking depending on ascent, descent and other properties. | |
184 | ||
c674f351 KH |
185 | When called from a program, expects these four arguments. |
186 | ||
187 | First two arguments START and END are positions (integers or markers) | |
188 | specifying the region. | |
189 | ||
1d1af02d DL |
190 | Optional 3rd argument COMPONENTS, if non-nil, is a character, a string |
191 | or a vector or list of integers and rules. | |
c674f351 KH |
192 | |
193 | If it is a character, it is an alternate character to display instead | |
194 | of the text in the region. | |
195 | ||
196 | If it is a string, the elements are alternate characters. | |
197 | ||
198 | If it is a vector or list, it is a sequence of alternate characters and | |
199 | composition rules, where (2N)th elements are characters and (2N+1)th | |
200 | elements are composition rules to specify how to compose (2N+2)th | |
201 | elements with previously composed N glyphs. | |
202 | ||
203 | A composition rule is a cons of global and new glyph reference point | |
204 | symbols. See the documentation of `reference-point-alist' for more | |
205 | detail. | |
206 | ||
207 | Optional 4th argument MODIFICATION-FUNC is a function to call to | |
208 | adjust the composition when it gets invalid because of a change of | |
209 | text in the composition." | |
210 | (interactive "r") | |
211 | (let ((modified-p (buffer-modified-p)) | |
212 | (buffer-read-only nil)) | |
213 | (if (or (vectorp components) (listp components)) | |
214 | (setq components (encode-composition-components components))) | |
215 | (compose-region-internal start end components modification-func) | |
216 | (set-buffer-modified-p modified-p))) | |
217 | ||
c674f351 KH |
218 | (defun decompose-region (start end) |
219 | "Decompose text in the current region. | |
220 | ||
221 | When called from a program, expects two arguments, | |
222 | positions (integers or markers) specifying the region." | |
223 | (interactive "r") | |
224 | (let ((modified-p (buffer-modified-p)) | |
225 | (buffer-read-only nil)) | |
226 | (remove-text-properties start end '(composition nil)) | |
227 | (set-buffer-modified-p modified-p))) | |
228 | ||
c674f351 KH |
229 | (defun compose-string (string &optional start end components modification-func) |
230 | "Compose characters in string STRING. | |
231 | ||
c1750694 | 232 | The return value is STRING with the `composition' property put on all |
c674f351 KH |
233 | the characters in it. |
234 | ||
235 | Optional 2nd and 3rd arguments START and END specify the range of | |
c1750694 | 236 | STRING to be composed. They default to the beginning and the end of |
c674f351 KH |
237 | STRING respectively. |
238 | ||
239 | Optional 4th argument COMPONENTS, if non-nil, is a character or a | |
240 | sequence (vector, list, or string) of integers. See the function | |
241 | `compose-region' for more detail. | |
242 | ||
243 | Optional 5th argument MODIFICATION-FUNC is a function to call to | |
244 | adjust the composition when it gets invalid because of a change of | |
245 | text in the composition." | |
246 | (if (or (vectorp components) (listp components)) | |
247 | (setq components (encode-composition-components components))) | |
248 | (or start (setq start 0)) | |
249 | (or end (setq end (length string))) | |
250 | (compose-string-internal string start end components modification-func) | |
251 | string) | |
252 | ||
c674f351 KH |
253 | (defun decompose-string (string) |
254 | "Return STRING where `composition' property is removed." | |
255 | (remove-text-properties 0 (length string) '(composition nil) string) | |
256 | string) | |
257 | ||
c674f351 KH |
258 | (defun compose-chars (&rest args) |
259 | "Return a string from arguments in which all characters are composed. | |
260 | For relative composition, arguments are characters. | |
261 | For rule-based composition, Mth \(where M is odd) arguments are | |
262 | characters, and Nth \(where N is even) arguments are composition rules. | |
263 | A composition rule is a cons of glyph reference points of the form | |
264 | \(GLOBAL-REF-POINT . NEW-REF-POINT). See the documentation of | |
265 | `reference-point-alist' for more detail." | |
266 | (let (str components) | |
267 | (if (consp (car (cdr args))) | |
268 | ;; Rule-base composition. | |
269 | (let ((len (length args)) | |
270 | (tail (encode-composition-components args 'nocopy))) | |
271 | ||
272 | (while tail | |
273 | (setq str (cons (car tail) str)) | |
274 | (setq tail (nthcdr 2 tail))) | |
275 | (setq str (concat (nreverse str)) | |
276 | components args)) | |
277 | ;; Relative composition. | |
278 | (setq str (concat args))) | |
279 | (compose-string-internal str 0 (length str) components))) | |
280 | ||
c674f351 KH |
281 | (defun find-composition (pos &optional limit string detail-p) |
282 | "Return information about a composition at or nearest to buffer position POS. | |
283 | ||
284 | If the character at POS has `composition' property, the value is a list | |
285 | of FROM, TO, and VALID-P. | |
286 | ||
287 | FROM and TO specify the range of text that has the same `composition' | |
288 | property, VALID-P is non-nil if and only if this composition is valid. | |
289 | ||
290 | If there's no composition at POS, and the optional 2nd argument LIMIT | |
291 | is non-nil, search for a composition toward LIMIT. | |
292 | ||
293 | If no composition is found, return nil. | |
294 | ||
295 | Optional 3rd argument STRING, if non-nil, is a string to look for a | |
296 | composition in; nil means the current buffer. | |
297 | ||
298 | If a valid composition is found and the optional 4th argument DETAIL-P | |
299 | is non-nil, the return value is a list of FROM, TO, COMPONENTS, | |
300 | RELATIVE-P, MOD-FUNC, and WIDTH. | |
301 | ||
302 | COMPONENTS is a vector of integers, the meaning depends on RELATIVE-P. | |
303 | ||
304 | RELATIVE-P is t if the composition method is relative, else nil. | |
305 | ||
306 | If RELATIVE-P is t, COMPONENTS is a vector of characters to be | |
307 | composed. If RELATIVE-P is nil, COMPONENTS is a vector of characters | |
308 | and composition rules as described in `compose-region'. | |
309 | ||
310 | MOD-FUNC is a modification function of the composition. | |
311 | ||
312 | WIDTH is a number of columns the composition occupies on the screen." | |
313 | (let ((result (find-composition-internal pos limit string detail-p))) | |
314 | (if (and detail-p result (nth 2 result) (not (nth 3 result))) | |
315 | ;; This is a valid rule-base composition. | |
316 | (decode-composition-components (nth 2 result) 'nocopy)) | |
317 | result)) | |
318 | ||
319 | \f | |
7141ee65 | 320 | (defun compose-chars-after (pos &optional limit object) |
c674f351 KH |
321 | "Compose characters in current buffer after position POS. |
322 | ||
323 | It looks up the char-table `composition-function-table' (which see) by | |
324 | a character after POS. If non-nil value is found, the format of the | |
325 | value should be an alist of PATTERNs vs FUNCs, where PATTERNs are | |
326 | regular expressions and FUNCs are functions. If the text after POS | |
327 | matches one of PATTERNs, call the corresponding FUNC with three | |
328 | arguments POS, TO, and PATTERN, where TO is the end position of text | |
329 | matching PATTERN, and return what FUNC returns. Otherwise, return | |
330 | nil. | |
331 | ||
332 | FUNC is responsible for composing the text properly. The return value | |
333 | is: | |
334 | nil -- if no characters were composed. | |
335 | CHARS (integer) -- if CHARS characters were composed. | |
336 | ||
337 | Optional 2nd arg LIMIT, if non-nil, limits the matching of text. | |
338 | ||
7141ee65 | 339 | Optional 3rd arg OBJECT, if non-nil, is a string that contains the |
1d1af02d | 340 | text to compose. In that case, POS and LIMIT index into the string. |
7141ee65 | 341 | |
c674f351 KH |
342 | This function is the default value of `compose-chars-after-function'." |
343 | (let ((tail (aref composition-function-table (char-after pos))) | |
344 | pattern func result) | |
345 | (when tail | |
339cebdc KH |
346 | (save-match-data |
347 | (save-excursion | |
71296446 | 348 | (while (and tail (not func)) |
339cebdc KH |
349 | (setq pattern (car (car tail)) |
350 | func (cdr (car tail))) | |
351 | (goto-char pos) | |
352 | (if (if limit | |
353 | (and (re-search-forward pattern limit t) | |
354 | (= (match-beginning 0) pos)) | |
355 | (looking-at pattern)) | |
356 | (setq result (funcall func pos (match-end 0) pattern nil)) | |
357 | (setq func nil tail (cdr tail))))))) | |
c674f351 KH |
358 | result)) |
359 | ||
c674f351 KH |
360 | (defun compose-last-chars (args) |
361 | "Compose last characters. | |
3b923ad8 KH |
362 | The argument is a parameterized event of the form |
363 | \(compose-last-chars N COMPONENTS), | |
364 | where N is the number of characters before point to compose, | |
365 | COMPONENTS, if non-nil, is the same as the argument to `compose-region' | |
366 | \(which see). If it is nil, `compose-chars-after' is called, | |
367 | and that function find a proper rule to compose the target characters. | |
c674f351 KH |
368 | This function is intended to be used from input methods. |
369 | The global keymap binds special event `compose-last-chars' to this | |
3b923ad8 | 370 | function. Input method may generate an event (compose-last-chars N COMPONENTS) |
c674f351 KH |
371 | after a sequence character events." |
372 | (interactive "e") | |
373 | (let ((chars (nth 1 args))) | |
374 | (if (and (numberp chars) | |
375 | (>= (- (point) (point-min)) chars)) | |
3b923ad8 KH |
376 | (if (nth 2 args) |
377 | (compose-region (- (point) chars) (point) (nth 2 args)) | |
378 | (compose-chars-after (- (point) chars) (point)))))) | |
c674f351 | 379 | |
68fbe650 | 380 | (global-set-key [compose-last-chars] 'compose-last-chars) |
c674f351 KH |
381 | |
382 | \f | |
68fbe650 KH |
383 | ;;; Automatic character composition. |
384 | ||
385 | (defvar composition-function-table | |
386 | (make-char-table nil) | |
387 | "Char table of functions for automatic character composition. | |
388 | For each character that has to be composed automatically with | |
389 | preceding and/or following characters, this char table contains | |
390 | a function to call to compose that character. | |
391 | ||
392 | Each function is called with two arguments, POS and STRING. | |
393 | ||
394 | If STRING is nil, POS is a position in the current buffer, and the | |
395 | function has to compose a character at POS with surrounding characters | |
396 | in the current buffer. | |
397 | ||
1d1af02d | 398 | Otherwise, STRING is a string, and POS is an index into the string. In |
68fbe650 KH |
399 | this case, the function has to compose a character at POS with |
400 | surrounding characters in the string. | |
401 | ||
402 | See also the command `toggle-auto-composition'.") | |
403 | ||
404 | ;; Copied from font-lock.el. | |
405 | (eval-when-compile | |
68fbe650 KH |
406 | ;; Borrowed from lazy-lock.el. |
407 | ;; We use this to preserve or protect things when modifying text properties. | |
408 | (defmacro save-buffer-state (varlist &rest body) | |
409 | "Bind variables according to VARLIST and eval BODY restoring buffer state." | |
ba8972b6 KH |
410 | `(let* ,(append varlist |
411 | '((modified (buffer-modified-p)) (buffer-undo-list t) | |
412 | (inhibit-read-only t) (inhibit-point-motion-hooks t) | |
413 | (inhibit-modification-hooks t) | |
414 | deactivate-mark buffer-file-name buffer-file-truename)) | |
415 | ,@body | |
416 | (unless modified | |
417 | (restore-buffer-modified-p nil)))) | |
1d1af02d | 418 | ;; Fixme: This makes bootstrapping fail with this error. |
ba8972b6 KH |
419 | ;; Symbol's function definition is void: eval-defun |
420 | ;;(def-edebug-spec save-buffer-state let) | |
421 | ) | |
68fbe650 | 422 | |
02bf0a0a KH |
423 | (put 'save-buffer-state 'lisp-indent-function 1) |
424 | ||
68fbe650 KH |
425 | (defun auto-compose-chars (pos string) |
426 | "Compose characters after the buffer position POS. | |
1d1af02d | 427 | If STRING is non-nil, it is a string, and POS is an index into the string. |
68fbe650 KH |
428 | In that case, compose characters in the string. |
429 | ||
430 | This function is the default value of `auto-composition-function' (which see)." | |
431 | (save-buffer-state nil | |
c8e89221 KH |
432 | (save-excursion |
433 | (save-match-data | |
1b9d9876 KH |
434 | (condition-case nil |
435 | (let ((start pos) | |
436 | (limit (if string (length string) (point-max))) | |
437 | ch func newpos) | |
438 | (setq limit | |
439 | (or (text-property-any pos limit 'auto-composed t string) | |
440 | limit) | |
441 | pos | |
442 | (catch 'tag | |
8a0e01e2 KH |
443 | (if string |
444 | (while (< pos limit) | |
445 | (setq ch (aref string pos)) | |
446 | (if (= ch ?\n) | |
447 | (throw 'tag (1+ pos))) | |
448 | (setq func (aref composition-function-table ch)) | |
449 | (if (and (functionp func) | |
450 | (setq newpos (funcall func pos string)) | |
451 | (> newpos pos)) | |
452 | (setq pos newpos) | |
453 | (setq pos (1+ pos)))) | |
454 | (while (< pos limit) | |
455 | (setq ch (char-after pos)) | |
456 | (if (= ch ?\n) | |
457 | (throw 'tag (1+ pos))) | |
458 | (setq func (aref composition-function-table ch)) | |
459 | (if (and (functionp func) | |
460 | (setq newpos (funcall func pos string)) | |
461 | (> newpos pos)) | |
462 | (setq pos newpos) | |
463 | (setq pos (1+ pos))))) | |
464 | limit)) | |
1b9d9876 KH |
465 | (put-text-property start pos 'auto-composed t string)) |
466 | (error nil)))))) | |
68fbe650 KH |
467 | |
468 | (setq auto-composition-function 'auto-compose-chars) | |
469 | ||
470 | (defun toggle-auto-composition (&optional arg) | |
471 | "Change whether automatic character composition is enabled in this buffer. | |
472 | With arg, enable it iff arg is positive." | |
473 | (interactive "P") | |
474 | (let ((enable (if (null arg) (not auto-composition-function) | |
475 | (> (prefix-numeric-value arg) 0)))) | |
476 | (if enable | |
477 | (kill-local-variable 'auto-composition-function) | |
478 | (make-local-variable 'auto-composition-function) | |
479 | (setq auto-composition-function nil) | |
480 | (save-buffer-state nil | |
481 | (save-restriction | |
482 | (widen) | |
483 | (decompose-region (point-min) (point-max))))) | |
484 | ||
485 | (save-buffer-state nil | |
486 | (save-restriction | |
487 | (widen) | |
488 | (put-text-property (point-min) (point-max) 'auto-composed nil))))) | |
bd4a85b9 KH |
489 | |
490 | (defun auto-compose-region (from to) | |
491 | "Force automatic character composition on the region FROM and TO." | |
492 | (save-excursion | |
493 | (if (get-text-property from 'auto-composed) | |
494 | (setq from (next-single-property-change from 'auto-composed nil to))) | |
495 | (goto-char from) | |
496 | (let ((modified-p (buffer-modified-p)) | |
497 | (inhibit-read-only '(composition auto-composed)) | |
498 | (stop (next-single-property-change (point) 'auto-composed nil to))) | |
499 | (while (< (point) to) | |
500 | (if (= (point) stop) | |
501 | (progn | |
502 | (goto-char (next-single-property-change (point) | |
503 | 'auto-composed nil to)) | |
504 | (setq stop (next-single-property-change (point) | |
505 | 'auto-composed nil to))) | |
506 | (let ((func (aref composition-function-table (following-char))) | |
507 | (pos (point))) | |
508 | (if (functionp func) | |
509 | (goto-char (funcall func (point) nil))) | |
510 | (if (<= (point) pos) | |
511 | (forward-char 1))))) | |
512 | (put-text-property from to 'auto-composed t) | |
513 | (set-buffer-modified-p modified-p)))) | |
514 | ||
c674f351 KH |
515 | \f |
516 | ;;; The following codes are only for backward compatibility with Emacs | |
9d5d96a6 | 517 | ;;; 20.4 and earlier. |
c674f351 | 518 | |
c674f351 KH |
519 | (defun decompose-composite-char (char &optional type with-composition-rule) |
520 | "Convert CHAR to string. | |
c674f351 KH |
521 | |
522 | If optional 2nd arg TYPE is non-nil, it is `string', `list', or | |
1ea62389 JB |
523 | `vector'. In this case, CHAR is converted to string, list of CHAR, or |
524 | vector of CHAR respectively. | |
525 | Optional 3rd arg WITH-COMPOSITION-RULE is ignored." | |
c674f351 KH |
526 | (cond ((or (null type) (eq type 'string)) (char-to-string char)) |
527 | ((eq type 'list) (list char)) | |
528 | (t (vector char)))) | |
529 | ||
8d787845 KH |
530 | (make-obsolete 'decompose-composite-char 'char-to-string "21.1") |
531 | ||
c674f351 KH |
532 | \f |
533 | ;;; composite.el ends here |