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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 | |
086add15 LK |
22 | ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
23 | ;; Boston, MA 02110-1301, USA. | |
c674f351 | 24 | |
60370d40 PJ |
25 | ;;; Commentary: |
26 | ||
c674f351 KH |
27 | ;;; Code: |
28 | ||
29 | ;;;###autoload | |
30 | (defconst reference-point-alist | |
31 | '((tl . 0) (tc . 1) (tr . 2) | |
32 | (Bl . 3) (Bc . 4) (Br . 5) | |
33 | (bl . 6) (bc . 7) (br . 8) | |
34 | (cl . 9) (cc . 10) (cr . 11) | |
35 | (top-left . 0) (top-center . 1) (top-right . 2) | |
36 | (base-left . 3) (base-center . 4) (base-right . 5) | |
37 | (bottom-left . 6) (bottom-center . 7) (bottom-right . 8) | |
38 | (center-left . 9) (center-center . 10) (center-right . 11) | |
39 | ;; For backward compatibility... | |
40 | (ml . 3) (mc . 10) (mr . 5) | |
41 | (mid-left . 3) (mid-center . 10) (mid-right . 5)) | |
42 | "Alist of symbols vs integer codes of glyph reference points. | |
43 | A glyph reference point symbol is to be used to specify a composition | |
44 | rule in COMPONENTS argument to such functions as `compose-region' and | |
45 | `make-composition'. | |
46 | ||
47 | Meanings of glyph reference point codes are as follows: | |
48 | ||
49 | 0----1----2 <---- ascent 0:tl or top-left | |
50 | | | 1:tc or top-center | |
51 | | | 2:tr or top-right | |
52 | | | 3:Bl or base-left 9:cl or center-left | |
53 | 9 10 11 <---- center 4:Bc or base-center 10:cc or center-center | |
54 | | | 5:Br or base-right 11:cr or center-right | |
55 | --3----4----5-- <-- baseline 6:bl or bottom-left | |
56 | | | 7:bc or bottom-center | |
57 | 6----7----8 <---- descent 8:br or bottom-right | |
58 | ||
59 | Glyph reference point symbols are to be used to specify composition | |
60 | rule of the form \(GLOBAL-REF-POINT . NEW-REF-POINT), where | |
61 | GLOBAL-REF-POINT is a reference point in the overall glyphs already | |
62 | composed, and NEW-REF-POINT is a reference point in the new glyph to | |
63 | be added. | |
64 | ||
65 | For instance, if GLOBAL-REF-POINT is `br' (bottom-right) and | |
8f625692 | 66 | NEW-REF-POINT is `tc' (top-center), the overall glyph is updated as |
c674f351 KH |
67 | follows (the point `*' corresponds to both reference points): |
68 | ||
69 | +-------+--+ <--- new ascent | |
70 | | | | | |
71 | | global| | | |
72 | | glyph | | | |
73 | -- | | |-- <--- baseline \(doesn't change) | |
74 | +----+--*--+ | |
75 | | | new | | |
76 | | |glyph| | |
77 | +----+-----+ <--- new descent | |
78 | ") | |
79 | ||
c674f351 | 80 | |
59a2dac0 | 81 | ;;;###autoload |
c674f351 | 82 | (defun encode-composition-rule (rule) |
59a2dac0 KH |
83 | "Encode composition rule RULE into an integer value. |
84 | RULE is a cons of global and new reference point symbols | |
2624e2ac | 85 | \(see `reference-point-alist')." |
59a2dac0 KH |
86 | |
87 | ;; This must be compatible with C macro COMPOSITION_ENCODE_RULE | |
88 | ;; defined in composite.h. | |
89 | ||
c674f351 KH |
90 | (if (and (integerp rule) (< rule 144)) |
91 | ;; Already encoded. | |
92 | rule | |
93 | (or (consp rule) | |
94 | (error "Invalid composition rule: %S" rule)) | |
95 | (let ((gref (car rule)) | |
96 | (nref (cdr rule))) | |
97 | (or (integerp gref) | |
98 | (setq gref (cdr (assq gref reference-point-alist)))) | |
99 | (or (integerp nref) | |
100 | (setq nref (cdr (assq nref reference-point-alist)))) | |
101 | (or (and (>= gref 0) (< gref 12) (>= nref 0) (< nref 12)) | |
71296446 | 102 | (error "Invalid composition rule: %S" rule)) |
c674f351 KH |
103 | (+ (* gref 12) nref)))) |
104 | ||
105 | ;; Decode encoded composition rule RULE-CODE. The value is a cons of | |
106 | ;; global and new reference point symbols. | |
107 | ;; This must be compatible with C macro COMPOSITION_DECODE_RULE | |
108 | ;; defined in composite.h. | |
109 | ||
110 | (defun decode-composition-rule (rule-code) | |
111 | (or (and (natnump rule-code) (< rule-code 144)) | |
112 | (error "Invalid encoded composition rule: %S" rule-code)) | |
113 | (let ((gref (car (rassq (/ rule-code 12) reference-point-alist))) | |
114 | (nref (car (rassq (% rule-code 12) reference-point-alist)))) | |
115 | (or (and gref (symbolp gref) nref (symbolp nref)) | |
116 | (error "Invalid composition rule code: %S" rule-code)) | |
117 | (cons gref nref))) | |
118 | ||
119 | ;; Encode composition rules in composition components COMPONENTS. The | |
120 | ;; value is a copy of COMPONENTS, where composition rules (cons of | |
121 | ;; global and new glyph reference point symbols) are replaced with | |
122 | ;; encoded composition rules. Optional 2nd argument NOCOPY non-nil | |
123 | ;; means don't make a copy but modify COMPONENTS directly. | |
124 | ||
125 | (defun encode-composition-components (components &optional nocopy) | |
126 | (or nocopy | |
127 | (setq components (copy-sequence components))) | |
128 | (if (vectorp components) | |
129 | (let ((len (length components)) | |
130 | (i 1)) | |
131 | (while (< i len) | |
132 | (aset components i | |
133 | (encode-composition-rule (aref components i))) | |
134 | (setq i (+ i 2)))) | |
135 | (let ((tail (cdr components))) | |
136 | (while tail | |
137 | (setcar tail | |
138 | (encode-composition-rule (car tail))) | |
139 | (setq tail (nthcdr 2 tail))))) | |
140 | components) | |
141 | ||
142 | ;; Decode composition rule codes in composition components COMPONENTS. | |
143 | ;; The value is a copy of COMPONENTS, where composition rule codes are | |
144 | ;; replaced with composition rules (cons of global and new glyph | |
145 | ;; reference point symbols). Optional 2nd argument NOCOPY non-nil | |
146 | ;; means don't make a copy but modify COMPONENTS directly. | |
147 | ;; It is assumed that COMPONENTS is a vector and is for rule-base | |
148 | ;; composition, thus (2N+1)th elements are rule codes. | |
149 | ||
150 | (defun decode-composition-components (components &optional nocopy) | |
151 | (or nocopy | |
152 | (setq components (copy-sequence components))) | |
153 | (let ((len (length components)) | |
154 | (i 1)) | |
155 | (while (< i len) | |
156 | (aset components i | |
157 | (decode-composition-rule (aref components i))) | |
158 | (setq i (+ i 2)))) | |
159 | components) | |
160 | ||
161 | ;;;###autoload | |
162 | (defun compose-region (start end &optional components modification-func) | |
163 | "Compose characters in the current region. | |
164 | ||
c9f60860 KH |
165 | Characters are composed relatively, i.e. composed by overstricking or |
166 | stacking depending on ascent, descent and other properties. | |
167 | ||
c674f351 KH |
168 | When called from a program, expects these four arguments. |
169 | ||
170 | First two arguments START and END are positions (integers or markers) | |
171 | specifying the region. | |
172 | ||
173 | Optional 3rd argument COMPONENTS, if non-nil, is a character or a | |
c9f60860 KH |
174 | sequence (vector, list, or string) of integers. In this case, |
175 | characters are composed not relatively but according to COMPONENTS. | |
c674f351 KH |
176 | |
177 | If it is a character, it is an alternate character to display instead | |
178 | of the text in the region. | |
179 | ||
180 | If it is a string, the elements are alternate characters. | |
181 | ||
182 | If it is a vector or list, it is a sequence of alternate characters and | |
183 | composition rules, where (2N)th elements are characters and (2N+1)th | |
184 | elements are composition rules to specify how to compose (2N+2)th | |
185 | elements with previously composed N glyphs. | |
186 | ||
187 | A composition rule is a cons of global and new glyph reference point | |
188 | symbols. See the documentation of `reference-point-alist' for more | |
189 | detail. | |
190 | ||
191 | Optional 4th argument MODIFICATION-FUNC is a function to call to | |
192 | adjust the composition when it gets invalid because of a change of | |
193 | text in the composition." | |
194 | (interactive "r") | |
195 | (let ((modified-p (buffer-modified-p)) | |
196 | (buffer-read-only nil)) | |
197 | (if (or (vectorp components) (listp components)) | |
198 | (setq components (encode-composition-components components))) | |
199 | (compose-region-internal start end components modification-func) | |
e3748ba2 | 200 | (restore-buffer-modified-p modified-p))) |
c674f351 KH |
201 | |
202 | ;;;###autoload | |
203 | (defun decompose-region (start end) | |
204 | "Decompose text in the current region. | |
205 | ||
206 | When called from a program, expects two arguments, | |
207 | positions (integers or markers) specifying the region." | |
208 | (interactive "r") | |
209 | (let ((modified-p (buffer-modified-p)) | |
210 | (buffer-read-only nil)) | |
211 | (remove-text-properties start end '(composition nil)) | |
212 | (set-buffer-modified-p modified-p))) | |
213 | ||
214 | ;;;###autoload | |
215 | (defun compose-string (string &optional start end components modification-func) | |
216 | "Compose characters in string STRING. | |
217 | ||
218 | The return value is STRING where `composition' property is put on all | |
219 | the characters in it. | |
220 | ||
221 | Optional 2nd and 3rd arguments START and END specify the range of | |
2624e2ac | 222 | STRING to be composed. They default to the beginning and the end of |
c674f351 KH |
223 | STRING respectively. |
224 | ||
225 | Optional 4th argument COMPONENTS, if non-nil, is a character or a | |
226 | sequence (vector, list, or string) of integers. See the function | |
227 | `compose-region' for more detail. | |
228 | ||
229 | Optional 5th argument MODIFICATION-FUNC is a function to call to | |
230 | adjust the composition when it gets invalid because of a change of | |
231 | text in the composition." | |
232 | (if (or (vectorp components) (listp components)) | |
233 | (setq components (encode-composition-components components))) | |
234 | (or start (setq start 0)) | |
235 | (or end (setq end (length string))) | |
236 | (compose-string-internal string start end components modification-func) | |
237 | string) | |
238 | ||
239 | ;;;###autoload | |
240 | (defun decompose-string (string) | |
241 | "Return STRING where `composition' property is removed." | |
242 | (remove-text-properties 0 (length string) '(composition nil) string) | |
243 | string) | |
244 | ||
245 | ;;;###autoload | |
246 | (defun compose-chars (&rest args) | |
247 | "Return a string from arguments in which all characters are composed. | |
248 | For relative composition, arguments are characters. | |
249 | For rule-based composition, Mth \(where M is odd) arguments are | |
250 | characters, and Nth \(where N is even) arguments are composition rules. | |
251 | A composition rule is a cons of glyph reference points of the form | |
252 | \(GLOBAL-REF-POINT . NEW-REF-POINT). See the documentation of | |
253 | `reference-point-alist' for more detail." | |
254 | (let (str components) | |
255 | (if (consp (car (cdr args))) | |
256 | ;; Rule-base composition. | |
257 | (let ((len (length args)) | |
258 | (tail (encode-composition-components args 'nocopy))) | |
259 | ||
260 | (while tail | |
261 | (setq str (cons (car tail) str)) | |
262 | (setq tail (nthcdr 2 tail))) | |
263 | (setq str (concat (nreverse str)) | |
264 | components args)) | |
265 | ;; Relative composition. | |
266 | (setq str (concat args))) | |
267 | (compose-string-internal str 0 (length str) components))) | |
268 | ||
269 | ;;;###autoload | |
270 | (defun find-composition (pos &optional limit string detail-p) | |
271 | "Return information about a composition at or nearest to buffer position POS. | |
272 | ||
273 | If the character at POS has `composition' property, the value is a list | |
274 | of FROM, TO, and VALID-P. | |
275 | ||
276 | FROM and TO specify the range of text that has the same `composition' | |
277 | property, VALID-P is non-nil if and only if this composition is valid. | |
278 | ||
279 | If there's no composition at POS, and the optional 2nd argument LIMIT | |
280 | is non-nil, search for a composition toward LIMIT. | |
281 | ||
282 | If no composition is found, return nil. | |
283 | ||
284 | Optional 3rd argument STRING, if non-nil, is a string to look for a | |
285 | composition in; nil means the current buffer. | |
286 | ||
287 | If a valid composition is found and the optional 4th argument DETAIL-P | |
288 | is non-nil, the return value is a list of FROM, TO, COMPONENTS, | |
289 | RELATIVE-P, MOD-FUNC, and WIDTH. | |
290 | ||
291 | COMPONENTS is a vector of integers, the meaning depends on RELATIVE-P. | |
292 | ||
293 | RELATIVE-P is t if the composition method is relative, else nil. | |
294 | ||
295 | If RELATIVE-P is t, COMPONENTS is a vector of characters to be | |
296 | composed. If RELATIVE-P is nil, COMPONENTS is a vector of characters | |
297 | and composition rules as described in `compose-region'. | |
298 | ||
299 | MOD-FUNC is a modification function of the composition. | |
300 | ||
301 | WIDTH is a number of columns the composition occupies on the screen." | |
302 | (let ((result (find-composition-internal pos limit string detail-p))) | |
303 | (if (and detail-p result (nth 2 result) (not (nth 3 result))) | |
304 | ;; This is a valid rule-base composition. | |
305 | (decode-composition-components (nth 2 result) 'nocopy)) | |
306 | result)) | |
307 | ||
308 | \f | |
61dc47f5 | 309 | ;;;###autoload |
7141ee65 | 310 | (defun compose-chars-after (pos &optional limit object) |
c674f351 KH |
311 | "Compose characters in current buffer after position POS. |
312 | ||
313 | It looks up the char-table `composition-function-table' (which see) by | |
314 | a character after POS. If non-nil value is found, the format of the | |
315 | value should be an alist of PATTERNs vs FUNCs, where PATTERNs are | |
316 | regular expressions and FUNCs are functions. If the text after POS | |
317 | matches one of PATTERNs, call the corresponding FUNC with three | |
318 | arguments POS, TO, and PATTERN, where TO is the end position of text | |
319 | matching PATTERN, and return what FUNC returns. Otherwise, return | |
320 | nil. | |
321 | ||
322 | FUNC is responsible for composing the text properly. The return value | |
323 | is: | |
324 | nil -- if no characters were composed. | |
325 | CHARS (integer) -- if CHARS characters were composed. | |
326 | ||
327 | Optional 2nd arg LIMIT, if non-nil, limits the matching of text. | |
328 | ||
7141ee65 KH |
329 | Optional 3rd arg OBJECT, if non-nil, is a string that contains the |
330 | text to compose. In that case, POS and LIMIT index to the string. | |
331 | ||
c674f351 KH |
332 | This function is the default value of `compose-chars-after-function'." |
333 | (let ((tail (aref composition-function-table (char-after pos))) | |
334 | pattern func result) | |
335 | (when tail | |
339cebdc KH |
336 | (save-match-data |
337 | (save-excursion | |
71296446 | 338 | (while (and tail (not func)) |
339cebdc KH |
339 | (setq pattern (car (car tail)) |
340 | func (cdr (car tail))) | |
341 | (goto-char pos) | |
342 | (if (if limit | |
343 | (and (re-search-forward pattern limit t) | |
344 | (= (match-beginning 0) pos)) | |
345 | (looking-at pattern)) | |
346 | (setq result (funcall func pos (match-end 0) pattern nil)) | |
347 | (setq func nil tail (cdr tail))))))) | |
c674f351 KH |
348 | result)) |
349 | ||
350 | ;;;###autoload | |
351 | (defun compose-last-chars (args) | |
352 | "Compose last characters. | |
3b923ad8 KH |
353 | The argument is a parameterized event of the form |
354 | \(compose-last-chars N COMPONENTS), | |
355 | where N is the number of characters before point to compose, | |
356 | COMPONENTS, if non-nil, is the same as the argument to `compose-region' | |
357 | \(which see). If it is nil, `compose-chars-after' is called, | |
2624e2ac | 358 | and that function finds a proper rule to compose the target characters. |
c674f351 KH |
359 | This function is intended to be used from input methods. |
360 | The global keymap binds special event `compose-last-chars' to this | |
3b923ad8 | 361 | function. Input method may generate an event (compose-last-chars N COMPONENTS) |
2624e2ac | 362 | after a sequence of character events." |
c674f351 KH |
363 | (interactive "e") |
364 | (let ((chars (nth 1 args))) | |
365 | (if (and (numberp chars) | |
366 | (>= (- (point) (point-min)) chars)) | |
3b923ad8 KH |
367 | (if (nth 2 args) |
368 | (compose-region (- (point) chars) (point) (nth 2 args)) | |
369 | (compose-chars-after (- (point) chars) (point)))))) | |
c674f351 KH |
370 | |
371 | ;;;###autoload(global-set-key [compose-last-chars] 'compose-last-chars) | |
372 | ||
373 | \f | |
374 | ;;; The following codes are only for backward compatibility with Emacs | |
9d5d96a6 | 375 | ;;; 20.4 and earlier. |
c674f351 KH |
376 | |
377 | ;;;###autoload | |
378 | (defun decompose-composite-char (char &optional type with-composition-rule) | |
379 | "Convert CHAR to string. | |
c674f351 KH |
380 | |
381 | If optional 2nd arg TYPE is non-nil, it is `string', `list', or | |
1ea62389 JB |
382 | `vector'. In this case, CHAR is converted to string, list of CHAR, or |
383 | vector of CHAR respectively. | |
384 | Optional 3rd arg WITH-COMPOSITION-RULE is ignored." | |
c674f351 KH |
385 | (cond ((or (null type) (eq type 'string)) (char-to-string char)) |
386 | ((eq type 'list) (list char)) | |
387 | (t (vector char)))) | |
388 | ||
6fcfeabf | 389 | ;;;###autoload |
8d787845 KH |
390 | (make-obsolete 'decompose-composite-char 'char-to-string "21.1") |
391 | ||
c674f351 | 392 | \f |
ab5796a9 MB |
393 | |
394 | ;;; arch-tag: ee703d77-1723-45d4-a31f-e9f0f867aa33 | |
c674f351 | 395 | ;;; composite.el ends here |