1 ;;; composite.el --- support character composition
3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 ;; National Institute of Advanced Industrial Science and Technology (AIST)
6 ;; Registration Number H14PRO021
8 ;; Author: Kenichi HANDA <handa@etl.go.jp>
9 ;; (according to ack.texi)
10 ;; Keywords: mule, multilingual, character composition
12 ;; This file is part of GNU Emacs.
14 ;; GNU Emacs is free software: you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation, either version 3 of the License, or
17 ;; (at your option) any later version.
19 ;; GNU Emacs is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
31 (eval-when-compile (require 'cl
))
33 (defconst reference-point-alist
34 '((tl .
0) (tc .
1) (tr .
2)
35 (Bl .
3) (Bc .
4) (Br .
5)
36 (bl .
6) (bc .
7) (br .
8)
37 (cl .
9) (cc .
10) (cr .
11)
38 (top-left .
0) (top-center .
1) (top-right .
2)
39 (base-left .
3) (base-center .
4) (base-right .
5)
40 (bottom-left .
6) (bottom-center .
7) (bottom-right .
8)
41 (center-left .
9) (center-center .
10) (center-right .
11)
42 ;; For backward compatibility...
43 (ml .
3) (mc .
10) (mr .
5)
44 (mid-left .
3) (mid-center .
10) (mid-right .
5))
45 "Alist of symbols vs integer codes of glyph reference points.
46 A glyph reference point symbol is to be used to specify a composition
47 rule in COMPONENTS argument to such functions as `compose-region'.
49 The meaning of glyph reference point codes is as follows:
51 0----1----2 <---- ascent 0:tl or top-left
52 | | 1:tc or top-center
54 | | 3:Bl or base-left 9:cl or center-left
55 9 10 11 <---- center 4:Bc or base-center 10:cc or center-center
56 | | 5:Br or base-right 11:cr or center-right
57 --3----4----5-- <-- baseline 6:bl or bottom-left
58 | | 7:bc or bottom-center
59 6----7----8 <---- descent 8:br or bottom-right
61 Glyph reference point symbols are to be used to specify composition
62 rule of the form \(GLOBAL-REF-POINT . NEW-REF-POINT), where
63 GLOBAL-REF-POINT is a reference point in the overall glyphs already
64 composed, and NEW-REF-POINT is a reference point in the new glyph to
67 For instance, if GLOBAL-REF-POINT is `br' (bottom-right) and
68 NEW-REF-POINT is `tc' (top-center), the overall glyph is updated as
69 follows (the point `*' corresponds to both reference points):
71 +-------+--+ <--- new ascent
75 -- | | |-- <--- baseline \(doesn't change)
79 +----+-----+ <--- new descent
81 A composition rule may have the form \(GLOBAL-REF-POINT
82 NEW-REF-POINT XOFF YOFF), where XOFF and YOFF specify how much
83 to shift NEW-REF-POINT from GLOBAL-REF-POINT. In this case, XOFF
84 and YOFF are integers in the range -100..100 representing the
85 shifting percentage against the font size.")
89 (defun encode-composition-rule (rule)
90 "Encode composition rule RULE into an integer value.
91 RULE is a cons of global and new reference point symbols
92 \(see `reference-point-alist')."
94 ;; This must be compatible with C macro COMPOSITION_ENCODE_RULE
95 ;; defined in composite.h.
97 (if (and (integerp rule
) (< rule
144))
101 (let ((gref (car rule
))
104 (if (consp nref
) ; (GREF NREF XOFF YOFF)
106 (setq xoff
(nth 1 nref
)
109 (or (and (>= xoff -
100) (<= xoff
100)
110 (>= yoff -
100) (<= yoff
100))
111 (error "Invalid composition rule: %s" rule
))
112 (setq xoff
(+ xoff
128) yoff
(+ yoff
128)))
114 (setq xoff
0 yoff
0))
116 (setq gref
(cdr (assq gref reference-point-alist
))))
118 (setq nref
(cdr (assq nref reference-point-alist
))))
119 (or (and (>= gref
0) (< gref
12) (>= nref
0) (< nref
12))
120 (error "Invalid composition rule: %S" rule
))
121 (logior (lsh xoff
16) (lsh yoff
8) (+ (* gref
12) nref
)))
122 (error "Invalid composition rule: %S" rule
))))
124 ;; Decode encoded composition rule RULE-CODE. The value is a cons of
125 ;; global and new reference point symbols.
126 ;; This must be compatible with C macro COMPOSITION_DECODE_RULE
127 ;; defined in composite.h.
129 (defun decode-composition-rule (rule-code)
130 (or (and (natnump rule-code
) (< rule-code
#x1000000
))
131 (error "Invalid encoded composition rule: %S" rule-code
))
132 (let ((xoff (lsh rule-code -
16))
133 (yoff (logand (lsh rule-code -
8) #xFF
))
135 (setq rule-code
(logand rule-code
#xFF
)
136 gref
(car (rassq (/ rule-code
12) reference-point-alist
))
137 nref
(car (rassq (% rule-code
12) reference-point-alist
)))
138 (or (and gref
(symbolp gref
) nref
(symbolp nref
))
139 (error "Invalid composition rule code: %S" rule-code
))
140 (if (and (= xoff
0) (= yoff
0))
142 (setq xoff
(- xoff
128) yoff
(- yoff
128))
143 (list gref xoff yoff nref
))))
145 ;; Encode composition rules in composition components COMPONENTS. The
146 ;; value is a copy of COMPONENTS, where composition rules (cons of
147 ;; global and new glyph reference point symbols) are replaced with
148 ;; encoded composition rules. Optional 2nd argument NOCOPY non-nil
149 ;; means don't make a copy but modify COMPONENTS directly.
151 (defun encode-composition-components (components &optional nocopy
)
153 (setq components
(copy-sequence components
)))
154 (if (vectorp components
)
155 (let ((len (length components
))
159 (encode-composition-rule (aref components i
)))
161 (let ((tail (cdr components
)))
164 (encode-composition-rule (car tail
)))
165 (setq tail
(nthcdr 2 tail
)))))
168 ;; Decode composition rule codes in composition components COMPONENTS.
169 ;; The value is a copy of COMPONENTS, where composition rule codes are
170 ;; replaced with composition rules (cons of global and new glyph
171 ;; reference point symbols). Optional 2nd argument NOCOPY non-nil
172 ;; means don't make a copy but modify COMPONENTS directly.
173 ;; It is assumed that COMPONENTS is a vector and is for rule-base
174 ;; composition, thus (2N+1)th elements are rule codes.
176 (defun decode-composition-components (components &optional nocopy
)
178 (setq components
(copy-sequence components
)))
179 (let ((len (length components
))
183 (decode-composition-rule (aref components i
)))
187 (defun compose-region (start end
&optional components modification-func
)
188 "Compose characters in the current region.
190 Characters are composed relatively, i.e. composed by overstriking
191 or stacking depending on ascent, descent and other metrics of
194 For instance, if the region has three characters \"XYZ\", X is
195 regarded as BASE glyph, and Y is displayed:
196 (1) above BASE if Y's descent value is not positive
197 (2) below BASE if Y's ascent value is not positive
198 (3) on BASE (i.e. at the BASE position) otherwise
199 and Z is displayed with the same rule while regarding the whole
202 When called from a program, expects these four arguments.
204 First two arguments START and END are positions (integers or markers)
205 specifying the region.
207 Optional 3rd argument COMPONENTS, if non-nil, is a character, a string
208 or a vector or list of integers and rules.
210 If it is a character, it is an alternate character to display instead
211 of the text in the region.
213 If it is a string, the elements are alternate characters. In
214 this case, TAB element has a special meaning. If the first
215 characer is TAB, the glyphs are displayed with left padding space
216 so that no pixel overlaps with the previous column. If the last
217 character is TAB, the glyphs are displayed with right padding
218 space so that no pixel overlaps with the following column.
220 If it is a vector or list, it is a sequence of alternate characters and
221 composition rules, where (2N)th elements are characters and (2N+1)th
222 elements are composition rules to specify how to compose (2N+2)th
223 elements with previously composed N glyphs.
225 A composition rule is a cons of global and new glyph reference point
226 symbols. See the documentation of `reference-point-alist' for more
229 Optional 4th 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."
233 (let ((modified-p (buffer-modified-p))
234 (inhibit-read-only t
))
235 (if (or (vectorp components
) (listp components
))
236 (setq components
(encode-composition-components components
)))
237 (compose-region-internal start end components modification-func
)
238 (restore-buffer-modified-p modified-p
)))
240 (defun decompose-region (start end
)
241 "Decompose text in the current region.
243 When called from a program, expects two arguments,
244 positions (integers or markers) specifying the region."
246 (let ((modified-p (buffer-modified-p))
247 (inhibit-read-only t
))
248 (remove-text-properties start end
'(composition nil
))
249 (restore-buffer-modified-p modified-p
)))
251 (defun compose-string (string &optional start end components modification-func
)
252 "Compose characters in string STRING.
254 The return value is STRING with the `composition' property put on all
255 the characters in it.
257 Optional 2nd and 3rd arguments START and END specify the range of
258 STRING to be composed. They default to the beginning and the end of
261 Optional 4th argument COMPONENTS, if non-nil, is a character or a
262 sequence (vector, list, or string) of integers. See the function
263 `compose-region' for more detail.
265 Optional 5th argument MODIFICATION-FUNC is a function to call to
266 adjust the composition when it gets invalid because of a change of
267 text in the composition."
268 (if (or (vectorp components
) (listp components
))
269 (setq components
(encode-composition-components components
)))
270 (or start
(setq start
0))
271 (or end
(setq end
(length string
)))
272 (compose-string-internal string start end components modification-func
)
275 (defun decompose-string (string)
276 "Return STRING where `composition' property is removed."
277 (remove-text-properties 0 (length string
) '(composition nil
) string
)
280 (defun compose-chars (&rest args
)
281 "Return a string from arguments in which all characters are composed.
282 For relative composition, arguments are characters.
283 For rule-based composition, Mth \(where M is odd) arguments are
284 characters, and Nth \(where N is even) arguments are composition rules.
285 A composition rule is a cons of glyph reference points of the form
286 \(GLOBAL-REF-POINT . NEW-REF-POINT). See the documentation of
287 `reference-point-alist' for more detail."
288 (let (str components
)
289 (if (consp (car (cdr args
)))
290 ;; Rule-base composition.
291 (let ((len (length args
))
292 (tail (encode-composition-components args
'nocopy
)))
295 (setq str
(cons (car tail
) str
))
296 (setq tail
(nthcdr 2 tail
)))
297 (setq str
(concat (nreverse str
))
299 ;; Relative composition.
300 (setq str
(concat args
)))
301 (compose-string-internal str
0 (length str
) components
)))
303 (defun find-composition (pos &optional limit string detail-p
)
304 "Return information about a composition at or near buffer position POS.
306 If the character at POS has `composition' property, the value is a list
309 FROM and TO specify the range of text that has the same `composition'
310 property, VALID-P is t if this composition is valid, and nil if not.
312 If there's no composition at POS, and the optional 2nd argument LIMIT
313 is non-nil, search for a composition toward the position given by LIMIT.
315 If no composition is found, return nil.
317 Optional 3rd argument STRING, if non-nil, is a string to look for a
318 composition in; nil means the current buffer.
320 If a valid composition is found and the optional 4th argument DETAIL-P
321 is non-nil, the return value is a list of the form
323 (FROM TO COMPONENTS RELATIVE-P MOD-FUNC WIDTH)
325 COMPONENTS is a vector of integers, the meaning depends on RELATIVE-P.
327 RELATIVE-P is t if the composition method is relative, else nil.
329 If RELATIVE-P is t, COMPONENTS is a vector of characters to be
330 composed. If RELATIVE-P is nil, COMPONENTS is a vector of characters
331 and composition rules as described in `compose-region'.
333 MOD-FUNC is a modification function of the composition.
335 WIDTH is a number of columns the composition occupies on the screen.
337 When Automatic Composition mode is on, this function also finds a
338 chunk of text that is automatically composed. If such a chunk is
339 found closer to POS than the position that has `composition'
340 property, the value is a list of FROM, TO, and a glyph-string
341 that specifies how the chunk is to be composed. See the function
342 `composition-get-gstring' for the format of the glyph-string."
343 (let ((result (find-composition-internal pos limit string detail-p
)))
344 (if (and detail-p
(> (length result
) 3) (nth 2 result
) (not (nth 3 result
)))
345 ;; This is a valid rule-base composition.
346 (decode-composition-components (nth 2 result
) 'nocopy
))
350 (defun compose-chars-after (pos &optional limit object
)
351 "Compose characters in current buffer after position POS.
353 It looks up the char-table `composition-function-table' (which
354 see) by a character at POS, and compose characters after POS
355 according to the contents of `composition-function-table'.
357 Optional 2nd arg LIMIT, if non-nil, limits characters to compose.
359 Optional 3rd arg OBJECT, if non-nil, is a string that contains the
360 text to compose. In that case, POS and LIMIT index into the string.
362 This function is the default value of `compose-chars-after-function'."
363 (let ((tail (aref composition-function-table
(char-after pos
)))
364 (font-obj (and (display-multi-font-p)
365 (and (not (stringp object
))
366 (font-at pos
(selected-window)))))
369 (setq limit
(if (stringp object
) (length object
) (point-max))))
370 (when (and font-obj tail
)
374 (if (functionp (car tail
))
375 (setq pattern nil func
(car tail
))
376 (setq pattern
(car (car tail
))
377 func
(cdr (car tail
))))
380 (if (and (if (stringp object
)
381 (eq (string-match pattern object
) 0)
382 (looking-at pattern
))
383 (<= (match-end 0) limit
))
385 (funcall func pos
(match-end 0) font-obj object
)))
386 (setq result
(funcall func pos limit font-obj object
)))
387 (if result
(setq tail nil
))))))
390 (defun compose-last-chars (args)
391 "Compose last characters.
392 The argument is a parameterized event of the form
393 \(compose-last-chars N COMPONENTS),
394 where N is the number of characters before point to compose,
395 COMPONENTS, if non-nil, is the same as the argument to `compose-region'
396 \(which see). If it is nil, `compose-chars-after' is called,
397 and that function finds a proper rule to compose the target characters.
398 This function is intended to be used from input methods.
399 The global keymap binds special event `compose-last-chars' to this
400 function. Input method may generate an event (compose-last-chars N COMPONENTS)
401 after a sequence of character events."
403 (let ((chars (nth 1 args
)))
404 (if (and (numberp chars
)
405 (>= (- (point) (point-min)) chars
))
407 (compose-region (- (point) chars
) (point) (nth 2 args
))
408 (compose-chars-after (- (point) chars
) (point))))))
410 (global-set-key [compose-last-chars
] 'compose-last-chars
)
413 ;;; Automatic character composition.
415 ;; Copied from font-lock.el.
417 ;; Borrowed from lazy-lock.el.
418 ;; We use this to preserve or protect things when modifying text properties.
419 (defmacro save-buffer-state
(varlist &rest body
)
420 "Bind variables according to VARLIST and eval BODY restoring buffer state."
421 `(let* ,(append varlist
422 '((modified (buffer-modified-p)) (buffer-undo-list t
)
423 (inhibit-read-only t
) (inhibit-point-motion-hooks t
)
424 (inhibit-modification-hooks t
)
425 deactivate-mark buffer-file-name buffer-file-truename
))
428 (restore-buffer-modified-p nil
))))
429 ;; Fixme: This makes bootstrapping fail with this error.
430 ;; Symbol's function definition is void: eval-defun
431 ;;(def-edebug-spec save-buffer-state let)
434 (put 'save-buffer-state
'lisp-indent-function
1)
436 ;; These macros must match with C macros LGSTRING_XXX and LGLYPH_XXX in font.h
437 (defsubst lgstring-header
(gstring) (aref gstring
0))
438 (defsubst lgstring-set-header
(gstring header
) (aset gstring
0 header
))
439 (defsubst lgstring-font
(gstring) (aref (lgstring-header gstring
) 0))
440 (defsubst lgstring-char
(gstring i
) (aref (lgstring-header gstring
) (1+ i
)))
441 (defsubst lgstring-char-len
(gstring) (1- (length (lgstring-header gstring
))))
442 (defsubst lgstring-shaped-p
(gstring) (aref gstring
1))
443 (defsubst lgstring-set-id
(gstring id
) (aset gstring
1 id
))
444 (defsubst lgstring-glyph
(gstring i
) (aref gstring
(+ i
2)))
445 (defsubst lgstring-glyph-len
(gstring) (- (length gstring
) 2))
446 (defsubst lgstring-set-glyph
(gstring i glyph
) (aset gstring
(+ i
2) glyph
))
448 (defsubst lglyph-from
(glyph) (aref glyph
0))
449 (defsubst lglyph-to
(glyph) (aref glyph
1))
450 (defsubst lglyph-char
(glyph) (aref glyph
2))
451 (defsubst lglyph-code
(glyph) (aref glyph
3))
452 (defsubst lglyph-width
(glyph) (aref glyph
4))
453 (defsubst lglyph-lbearing
(glyph) (aref glyph
5))
454 (defsubst lglyph-rbearing
(glyph) (aref glyph
6))
455 (defsubst lglyph-ascent
(glyph) (aref glyph
7))
456 (defsubst lglyph-descent
(glyph) (aref glyph
8))
457 (defsubst lglyph-adjustment
(glyph) (aref glyph
9))
459 (defsubst lglyph-set-from-to
(glyph from to
)
460 (progn (aset glyph
0 from
) (aset glyph
1 to
)))
461 (defsubst lglyph-set-char
(glyph char
) (aset glyph
2 char
))
462 (defsubst lglyph-set-code
(glyph code
) (aset glyph
3 code
))
463 (defsubst lglyph-set-width
(glyph width
) (aset glyph
4 width
))
464 (defsubst lglyph-set-adjustment
(glyph &optional xoff yoff wadjust
)
465 (aset glyph
9 (vector (or xoff
0) (or yoff
0) (or wadjust
0))))
467 (defsubst lglyph-copy
(glyph) (copy-sequence glyph
))
469 (defun lgstring-insert-glyph (gstring idx glyph
)
470 (let ((nglyphs (lgstring-glyph-len gstring
))
472 (while (and (< i nglyphs
) (setq g
(lgstring-glyph gstring i
)))
475 (setq gstring
(vconcat gstring
(vector glyph
)))
476 (if (< (1+ i
) nglyphs
)
477 (lgstring-set-glyph gstring
(1+ i
) nil
)))
479 (lgstring-set-glyph gstring i
(lgstring-glyph gstring
(1- i
)))
481 (lgstring-set-glyph gstring i glyph
)
484 (defun compose-glyph-string (gstring from to
)
485 (let ((glyph (lgstring-glyph gstring from
))
487 ascent descent lbearing rbearing
)
488 (setq from-pos
(lglyph-from glyph
)
489 to-pos
(lglyph-to (lgstring-glyph gstring
(1- to
))))
490 (lglyph-set-from-to glyph from-pos to-pos
)
491 (setq from
(1+ from
))
492 (while (and (< from to
)
493 (setq glyph
(lgstring-glyph gstring from
)))
494 (lglyph-set-from-to glyph from-pos to-pos
)
495 (let ((xoff (if (<= (lglyph-rbearing glyph
) 0) 0
496 (- (lglyph-width glyph
)))))
497 (lglyph-set-adjustment glyph xoff
0 0))
498 (setq from
(1+ from
)))
501 (defun compose-glyph-string-relative (gstring from to
&optional gap
)
502 (let ((font-object (lgstring-font gstring
))
503 (glyph (lgstring-glyph gstring from
))
505 ascent descent lbearing rbearing
)
507 (setq gap
(floor (* (font-get font-object
:size
) gap
)))
509 (setq from-pos
(lglyph-from glyph
)
510 to-pos
(lglyph-to (lgstring-glyph gstring
(1- to
)))
511 ascent
(lglyph-ascent glyph
)
512 descent
(lglyph-descent glyph
))
513 (lglyph-set-from-to glyph from-pos to-pos
)
514 (setq from
(1+ from
))
516 (setq glyph
(lgstring-glyph gstring from
))
517 (lglyph-set-from-to glyph from-pos to-pos
)
518 (let ((this-ascent (lglyph-ascent glyph
))
519 (this-descent (lglyph-descent glyph
))
521 (setq xoff
(if (<= (lglyph-rbearing glyph
) 0) 0
522 (- (lglyph-width glyph
))))
523 (if (> this-ascent
0)
524 (if (< this-descent
0)
525 (setq yoff
(- 0 ascent gap this-descent
)
526 ascent
(+ ascent gap this-ascent this-descent
))
528 (setq yoff
(+ descent gap this-ascent
)
529 descent
(+ descent gap this-ascent this-descent
)))
530 (if (or (/= xoff
0) (/= yoff
0))
531 (lglyph-set-adjustment glyph xoff yoff
0)))
532 (setq from
(1+ from
)))
535 (defun compose-gstring-for-graphic (gstring)
536 "Compose glyph-string GSTRING for graphic display.
537 Combining characters are composed with the preceding base
538 character. If the preceding character is not a base character,
539 each combining character is composed as a spacing character by
540 a padding space before and/or after the character.
542 All non-spacing characters have this function in
543 `composition-function-table' unless overwritten."
544 (let* ((header (lgstring-header gstring
))
545 (nchars (lgstring-char-len gstring
))
546 (nglyphs (lgstring-glyph-len gstring
))
547 (glyph (lgstring-glyph gstring
0)))
549 ;; A non-spacing character not following a proper base character.
551 (let ((lbearing (lglyph-lbearing glyph
))
552 (rbearing (lglyph-rbearing glyph
))
553 (width (lglyph-width glyph
))
556 (setq xoff
(- lbearing
))
557 (setq xoff
0 lbearing
0))
558 (if (< rbearing width
)
559 (setq rbearing width
))
560 (lglyph-set-adjustment glyph xoff
0 (- rbearing lbearing
))
563 ;; This sequence doesn't start with a proper base character.
564 ((memq (get-char-code-property (lgstring-char gstring
0)
566 '(Mn Mc Me Zs Zl Zp Cc Cf Cs
))
569 ;; A base character and the following non-spacing characters.
571 (let ((gstr (font-shape-gstring gstring
)))
573 (> (lglyph-to (lgstring-glyph gstr
0)) 0))
575 ;; The shaper of the font couldn't shape the gstring.
576 ;; Shape them according to canonical-combining-class.
577 (lgstring-set-id gstring nil
)
578 (let* ((width (lglyph-width glyph
))
579 (ascent (lglyph-ascent glyph
))
580 (descent (lglyph-descent glyph
))
581 (rbearing (lglyph-rbearing glyph
))
582 (lbearing (lglyph-lbearing glyph
))
583 (center (/ (+ lbearing rbearing
) 2))
584 (gap (round (* (font-get (lgstring-font gstring
) :size
) 0.1)))
587 (setq glyph
(lgstring-glyph gstring i
))
589 (let* ((class (get-char-code-property
590 (lglyph-char glyph
) 'canonical-combining-class
))
591 (lb (lglyph-lbearing glyph
))
592 (rb (lglyph-rbearing glyph
))
593 (as (lglyph-ascent glyph
))
594 (de (lglyph-descent glyph
))
597 (when (and class
(>= class
200) (<= class
240))
601 (setq xoff
(- lbearing ce
)
602 yoff
(if (> as
0) 0 (+ descent as
))))
604 (if (> as
0) (setq as
0))
605 (setq xoff
(- center ce
)
606 yoff
(if (> as
0) 0 (+ descent as
))))
608 (if (> as
0) (setq as
0))
609 (setq xoff
(- rbearing ce
)
610 yoff
(if (> as
0) 0 (+ descent as
))))
612 (setq xoff
(- lbearing rb
)))
614 (setq xoff
(- rbearing lb
)))
616 (setq xoff
(- lbearing ce
)
617 yoff
(if (>= de
0) 0 (- (- ascent
) de
))))
619 (setq xoff
(- center ce
)
620 yoff
(if (>= de
0) 0 (- (- ascent
) de
))))
622 (setq xoff
(- rbearing ce
)
623 yoff
(if (>= de
0) 0 (- (- ascent
) de
))))
625 (setq xoff
(- lbearing ce
)
626 yoff
(if (> as
0) 0 (+ descent as gap
))))
628 (setq xoff
(- center ce
)
629 yoff
(if (> as
0) 0 (+ descent as gap
))))
631 (setq xoff
(- rbearing ce
)
632 yoff
(if (> as
0) 0 (+ descent as gap
))))
634 (setq xoff
(- lbearing rb
)))
636 (setq xoff
(- rbearing lb
)))
638 (setq xoff
(- lbearing ce
)
639 yoff
(if (>= de
0) 0 (- (- ascent
) de gap
))))
641 (setq xoff
(- center ce
)
642 yoff
(if (>= de
0) 0 (- (- ascent
) de gap
))))
644 (setq xoff
(- rbearing ce
)
645 yoff
(if (>= de
0) 0 (- (+ ascent de
) gap
)))))
646 (lglyph-set-adjustment glyph
(- xoff width
) yoff
)
654 (setq descent de
))))))
656 (while (and (< i nglyphs
) (setq glyph
(lgstring-glyph gstring i
)))
657 (lglyph-set-from-to glyph
0 (1- nchars
))
661 (let ((elt `([,(purecopy "\\c.\\c^+") 1 compose-gstring-for-graphic
]
662 [nil
0 compose-gstring-for-graphic
])))
665 (if (memq val
'(Mn Mc Me
))
666 (set-char-table-range composition-function-table key elt
)))
667 unicode-category-table
))
669 (defun compose-gstring-for-terminal (gstring)
670 "Compose glyph string GSTRING for terminal display.
671 Non-spacing characters are composed with the preceding base
672 character. If the preceding character is not a base character,
673 each non-spacing character is composed as a spacing character by
674 prepending a space before it."
675 (let* ((header (lgstring-header gstring
))
676 (nchars (lgstring-char-len gstring
))
677 (nglyphs (lgstring-glyph-len gstring
))
679 (coding (lgstring-font gstring
))
681 (while (and (< i nglyphs
)
682 (setq glyph
(lgstring-glyph gstring i
)))
683 (if (not (char-charset (lglyph-char glyph
) coding
))
685 ;; As the terminal doesn't support this glyph, return a
686 ;; gstring in which each glyph is its own graphme-cluster
689 (while (and (< i nglyphs
)
690 (setq glyph
(lgstring-glyph gstring i
)))
691 (if (< (lglyph-width glyph
) 1)
692 (lglyph-set-width glyph
1))
693 (lglyph-set-from-to glyph i i
)
695 (if (= (lglyph-width glyph
) 0)
696 (if (eq (get-char-code-property (lglyph-char glyph
)
700 ;; Compose by replacing with a space.
701 (lglyph-set-char glyph
32)
702 (lglyph-set-width glyph
1)
704 ;; Compose by prepending a space.
705 (setq gstring
(lgstring-insert-glyph gstring i
707 nglyphs
(lgstring-glyph-len gstring
))
708 (setq glyph
(lgstring-glyph gstring i
))
709 (lglyph-set-char glyph
32)
710 (lglyph-set-width glyph
1)
712 (let ((from (lglyph-from glyph
))
713 (to (lglyph-to glyph
))
715 (while (and (< j nglyphs
)
716 (setq glyph
(lgstring-glyph gstring j
))
717 (char-charset (lglyph-char glyph
) coding
)
718 (= (lglyph-width glyph
) 0))
719 (setq to
(lglyph-to glyph
)
722 (setq glyph
(lgstring-glyph gstring i
))
723 (lglyph-set-from-to glyph from to
)
728 (defun auto-compose-chars (func from to font-object string
)
729 "Compose the characters at FROM by FUNC.
730 FUNC is called with one argument GSTRING which is built for characters
731 in the region FROM (inclusive) and TO (exclusive).
733 If the character are composed on a graphic display, FONT-OBJECT
734 is a font to use. Otherwise, FONT-OBJECT is nil, and the function
735 `compose-gstring-for-terminal' is used instead of FUNC.
737 If STRING is non-nil, it is a string, and FROM and TO are indices
738 into the string. In that case, compose characters in the string.
740 The value is a gstring containing information for shaping the characters.
742 This function is the default value of `auto-composition-function' (which see)."
743 (let ((gstring (composition-get-gstring from to font-object string
)))
744 (if (lgstring-shaped-p gstring
)
746 (or (fontp font-object
'font-object
)
747 (setq func
'compose-gstring-for-terminal
))
748 (funcall func gstring
))))
750 (put 'auto-composition-mode
'permanent-local t
)
752 (make-variable-buffer-local 'auto-composition-function
)
753 (setq-default auto-composition-function
'auto-compose-chars
)
756 (define-minor-mode auto-composition-mode
757 "Toggle Auto Composition mode.
758 With ARG, turn Auto Composition mode off if and only if ARG is a non-positive
759 number; if ARG is nil, toggle Auto Composition mode; anything else turns Auto
762 When Auto Composition is enabled, text characters are automatically composed
763 by functions registered in `composition-function-table' (which see).
765 You can use `global-auto-composition-mode' to turn on
766 Auto Composition mode in all buffers (this is the default).")
769 (define-minor-mode global-auto-composition-mode
770 "Toggle Auto-Composition mode in every possible buffer.
771 With prefix arg, turn Global-Auto-Composition mode on if and only if arg
773 See `auto-composition-mode' for more information on Auto-Composition mode."
774 :variable
(default-value 'auto-composition-mode
))
776 (defalias 'toggle-auto-composition
'auto-composition-mode
)
779 ;; The following codes are only for backward compatibility with Emacs
782 (defun decompose-composite-char (char &optional type with-composition-rule
)
783 "Convert CHAR to string.
785 If optional 2nd arg TYPE is non-nil, it is `string', `list', or
786 `vector'. In this case, CHAR is converted to string, list of CHAR, or
787 vector of CHAR respectively.
788 Optional 3rd arg WITH-COMPOSITION-RULE is ignored."
789 (cond ((or (null type
) (eq type
'string
)) (char-to-string char
))
790 ((eq type
'list
) (list char
))
793 (make-obsolete 'decompose-composite-char
'char-to-string
"21.1")
797 ;; arch-tag: ee703d77-1723-45d4-a31f-e9f0f867aa33
798 ;;; composite.el ends here