1 /* Composite sequence support.
2 Copyright (C) 2001-2011 Free Software Foundation, Inc.
3 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 National Institute of Advanced Industrial Science and Technology (AIST)
5 Registration Number H14PRO021
6 Copyright (C) 2003, 2006
7 National Institute of Advanced Industrial Science and Technology (AIST)
8 Registration Number H13PRO009
10 This file is part of GNU Emacs.
12 GNU Emacs is free software: you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation, either version 3 of the License, or
15 (at your option) any later version.
17 GNU Emacs is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
29 #include "character.h"
31 #include "intervals.h"
34 #include "dispextern.h"
36 #include "termhooks.h"
39 /* Emacs uses special text property `composition' to support character
40 composition. A sequence of characters that have the same (i.e. eq)
41 `composition' property value is treated as a single composite
42 sequence (we call it just `composition' here after). Characters in
43 a composition are all composed somehow on the screen.
45 The property value has this form when the composition is made:
46 ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
47 then turns to this form:
48 (COMPOSITION-ID . (LENGTH COMPONENTS-VEC . MODIFICATION-FUNC))
49 when the composition is registered in composition_hash_table and
50 composition_table. These rather peculiar structures were designed
51 to make it easy to distinguish them quickly (we can do that by
52 checking only the first element) and to extract LENGTH (from the
53 former form) and COMPOSITION-ID (from the latter form).
55 We register a composition when it is displayed, or when the width
56 is required (for instance, to calculate columns).
58 LENGTH -- Length of the composition. This information is used to
59 check the validity of the composition.
61 COMPONENTS -- Character, string, vector, list, or nil.
63 If it is nil, characters in the text are composed relatively
64 according to their metrics in font glyphs.
66 If it is a character or a string, the character or characters
67 in the string are composed relatively.
69 If it is a vector or list of integers, the element is a
70 character or an encoded composition rule. The characters are
71 composed according to the rules. (2N)th elements are
72 characters to be composed and (2N+1)th elements are
73 composition rules to tell how to compose (2N+2)th element with
74 the previously composed 2N glyphs.
76 COMPONENTS-VEC -- Vector of integers. In a relative composition,
77 the elements are the characters to be composed. In a rule-base
78 composition, the elements are characters or encoded
81 MODIFICATION-FUNC -- If non nil, it is a function to call when the
82 composition gets invalid after a modification in a buffer. If
83 it is nil, a function in `composition-function-table' of the
84 first character in the sequence is called.
86 COMPOSITION-ID --Identification number of the composition. It is
87 used as an index to composition_table for the composition.
89 When Emacs has to display a composition or has to know its
90 displaying width, the function get_composition_id is called. It
91 returns COMPOSITION-ID so that the caller can access the
92 information about the composition through composition_table. If a
93 COMPOSITION-ID has not yet been assigned to the composition,
94 get_composition_id checks the validity of `composition' property,
95 and, if valid, assigns a new ID, registers the information in
96 composition_hash_table and composition_table, and changes the form
97 of the property value. If the property is invalid,
98 get_composition_id returns -1 without changing the property value.
100 We use two tables to keep the information about composition;
101 composition_hash_table and composition_table.
103 The former is a hash table whose keys are COMPONENTS-VECs and
104 values are the corresponding COMPOSITION-IDs. This hash table is
105 weak, but as each key (COMPONENTS-VEC) is also kept as a value of the
106 `composition' property, it won't be collected as garbage until all
107 bits of text that have the same COMPONENTS-VEC are deleted.
109 The latter is a table of pointers to `struct composition' indexed
110 by COMPOSITION-ID. This structure keeps the other information (see
113 In general, a text property holds information about individual
114 characters. But, a `composition' property holds information about
115 a sequence of characters (in this sense, it is like the `intangible'
116 property). That means that we should not share the property value
117 in adjacent compositions -- we can't distinguish them if they have the
118 same property. So, after any changes, we call
119 `update_compositions' and change a property of one of adjacent
120 compositions to a copy of it. This function also runs a proper
121 composition modification function to make a composition that gets
122 invalid by the change valid again.
124 As the value of the `composition' property holds information about a
125 specific range of text, the value gets invalid if we change the
126 text in the range. We treat the `composition' property as always
127 rear-nonsticky (currently by setting default-text-properties to
128 (rear-nonsticky (composition))) and we never make properties of
129 adjacent compositions identical. Thus, any such changes make the
130 range just shorter. So, we can check the validity of the `composition'
131 property by comparing LENGTH information with the actual length of
137 Lisp_Object Qcomposition
;
139 /* Table of pointers to the structure `composition' indexed by
140 COMPOSITION-ID. This structure is for storing information about
141 each composition except for COMPONENTS-VEC. */
142 struct composition
**composition_table
;
144 /* The current size of `composition_table'. */
145 static ptrdiff_t composition_table_size
;
147 /* Number of compositions currently made. */
148 ptrdiff_t n_compositions
;
150 /* Hash table for compositions. The key is COMPONENTS-VEC of
151 `composition' property. The value is the corresponding
153 Lisp_Object composition_hash_table
;
155 static Lisp_Object Qauto_composed
;
156 static Lisp_Object Qauto_composition_function
;
157 /* Maximum number of characters to look back for
158 auto-compositions. */
159 #define MAX_AUTO_COMPOSITION_LOOKBACK 3
161 static Lisp_Object
Fcomposition_get_gstring (Lisp_Object
, Lisp_Object
,
162 Lisp_Object
, Lisp_Object
);
164 /* Temporary variable used in macros COMPOSITION_XXX. */
165 Lisp_Object composition_temp
;
168 /* Return COMPOSITION-ID of a composition at buffer position
169 CHARPOS/BYTEPOS and length NCHARS. The `composition' property of
170 the sequence is PROP. STRING, if non-nil, is a string that
171 contains the composition instead of the current buffer.
173 If the composition is invalid, return -1. */
176 get_composition_id (EMACS_INT charpos
, EMACS_INT bytepos
, EMACS_INT nchars
,
177 Lisp_Object prop
, Lisp_Object string
)
179 Lisp_Object id
, length
, components
, key
, *key_contents
;
181 struct Lisp_Hash_Table
*hash_table
= XHASH_TABLE (composition_hash_table
);
182 ptrdiff_t hash_index
;
183 EMACS_UINT hash_code
;
184 struct composition
*cmp
;
189 Form-A: ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
191 Form-B: (COMPOSITION-ID . (LENGTH COMPONENTS-VEC . MODIFICATION-FUNC))
193 if (nchars
== 0 || !CONSP (prop
))
194 goto invalid_composition
;
199 /* PROP should be Form-B. */
200 if (XINT (id
) < 0 || XINT (id
) >= n_compositions
)
201 goto invalid_composition
;
205 /* PROP should be Form-A.
206 Thus, ID should be (LENGTH . COMPONENTS). */
208 goto invalid_composition
;
210 if (!INTEGERP (length
) || XINT (length
) != nchars
)
211 goto invalid_composition
;
213 components
= XCDR (id
);
215 /* Check if the same composition has already been registered or not
216 by consulting composition_hash_table. The key for this table is
217 COMPONENTS (converted to a vector COMPONENTS-VEC) or, if it is
218 nil, vector of characters in the composition range. */
219 if (INTEGERP (components
))
220 key
= Fmake_vector (make_number (1), components
);
221 else if (STRINGP (components
) || CONSP (components
))
222 key
= Fvconcat (1, &components
);
223 else if (VECTORP (components
))
225 else if (NILP (components
))
227 key
= Fmake_vector (make_number (nchars
), Qnil
);
228 if (STRINGP (string
))
229 for (i
= 0; i
< nchars
; i
++)
231 FETCH_STRING_CHAR_ADVANCE (ch
, string
, charpos
, bytepos
);
232 XVECTOR (key
)->contents
[i
] = make_number (ch
);
235 for (i
= 0; i
< nchars
; i
++)
237 FETCH_CHAR_ADVANCE (ch
, charpos
, bytepos
);
238 XVECTOR (key
)->contents
[i
] = make_number (ch
);
242 goto invalid_composition
;
244 hash_index
= hash_lookup (hash_table
, key
, &hash_code
);
247 /* We have already registered the same composition. Change PROP
248 from Form-A above to Form-B while replacing COMPONENTS with
249 COMPONENTS-VEC stored in the hash table. We can directly
250 modify the cons cell of PROP because it is not shared. */
251 key
= HASH_KEY (hash_table
, hash_index
);
252 id
= HASH_VALUE (hash_table
, hash_index
);
254 XSETCDR (prop
, Fcons (make_number (nchars
), Fcons (key
, XCDR (prop
))));
258 /* This composition is a new one. We must register it. */
260 /* Check if we have sufficient memory to store this information. */
261 if (composition_table_size
== 0)
264 = (struct composition
**) xmalloc (sizeof (composition_table
[0]) * 256);
265 composition_table_size
= 256;
267 else if (composition_table_size
<= n_compositions
)
269 if ((min (MOST_POSITIVE_FIXNUM
,
270 min (PTRDIFF_MAX
, SIZE_MAX
) / sizeof composition_table
[0])
272 < composition_table_size
)
273 memory_full (SIZE_MAX
);
275 = (struct composition
**) xrealloc (composition_table
,
276 sizeof (composition_table
[0])
277 * (composition_table_size
+ 256));
278 composition_table_size
+= 256;
281 key_contents
= XVECTOR (key
)->contents
;
283 /* Check if the contents of COMPONENTS are valid if COMPONENTS is a
284 vector or a list. It should be a sequence of:
285 char1 rule1 char2 rule2 char3 ... ruleN charN+1 */
287 if (VECTORP (components
)
288 && ASIZE (components
) >= 2
289 && VECTORP (AREF (components
, 0)))
291 /* COMPONENTS is a glyph-string. */
292 EMACS_INT len
= ASIZE (key
);
294 for (i
= 1; i
< len
; i
++)
295 if (! VECTORP (AREF (key
, i
)))
296 goto invalid_composition
;
298 else if (VECTORP (components
) || CONSP (components
))
300 EMACS_INT len
= ASIZE (key
);
302 /* The number of elements should be odd. */
304 goto invalid_composition
;
305 /* All elements should be integers (character or encoded
306 composition rule). */
307 for (i
= 0; i
< len
; i
++)
309 if (!INTEGERP (key_contents
[i
]))
310 goto invalid_composition
;
314 /* Change PROP from Form-A above to Form-B. We can directly modify
315 the cons cell of PROP because it is not shared. */
316 XSETFASTINT (id
, n_compositions
);
318 XSETCDR (prop
, Fcons (make_number (nchars
), Fcons (key
, XCDR (prop
))));
320 /* Register the composition in composition_hash_table. */
321 hash_index
= hash_put (hash_table
, key
, id
, hash_code
);
323 /* Register the composition in composition_table. */
324 cmp
= (struct composition
*) xmalloc (sizeof (struct composition
));
326 cmp
->method
= (NILP (components
)
327 ? COMPOSITION_RELATIVE
328 : ((INTEGERP (components
) || STRINGP (components
))
329 ? COMPOSITION_WITH_ALTCHARS
330 : COMPOSITION_WITH_RULE_ALTCHARS
));
331 cmp
->hash_index
= hash_index
;
332 glyph_len
= (cmp
->method
== COMPOSITION_WITH_RULE_ALTCHARS
333 ? (ASIZE (key
) + 1) / 2
335 cmp
->glyph_len
= glyph_len
;
336 cmp
->offsets
= (short *) xmalloc (sizeof (short) * glyph_len
* 2);
339 if (cmp
->method
!= COMPOSITION_WITH_RULE_ALTCHARS
)
341 /* Relative composition. */
343 for (i
= 0; i
< glyph_len
; i
++)
346 ch
= XINT (key_contents
[i
]);
347 this_width
= (ch
== '\t' ? 1 : CHAR_WIDTH (ch
));
348 if (cmp
->width
< this_width
)
349 cmp
->width
= this_width
;
354 /* Rule-base composition. */
355 float leftmost
= 0.0, rightmost
;
357 ch
= XINT (key_contents
[0]);
358 rightmost
= ch
!= '\t' ? CHAR_WIDTH (ch
) : 1;
360 for (i
= 1; i
< glyph_len
; i
+= 2)
362 int rule
, gref
, nref
;
366 rule
= XINT (key_contents
[i
]);
367 ch
= XINT (key_contents
[i
+ 1]);
368 this_width
= ch
!= '\t' ? CHAR_WIDTH (ch
) : 1;
370 /* A composition rule is specified by an integer value
371 that encodes global and new reference points (GREF and
372 NREF). GREF and NREF are specified by numbers as
380 ---3---4---5--- baseline
384 COMPOSITION_DECODE_REFS (rule
, gref
, nref
);
385 this_left
= (leftmost
386 + (gref
% 3) * (rightmost
- leftmost
) / 2.0
387 - (nref
% 3) * this_width
/ 2.0);
389 if (this_left
< leftmost
)
390 leftmost
= this_left
;
391 if (this_left
+ this_width
> rightmost
)
392 rightmost
= this_left
+ this_width
;
395 cmp
->width
= rightmost
- leftmost
;
396 if (cmp
->width
< (rightmost
- leftmost
))
397 /* To get a ceiling integer value. */
401 composition_table
[n_compositions
] = cmp
;
403 return n_compositions
++;
406 /* Would it be better to remove this `composition' property? */
411 /* Find a static composition at or nearest to position POS of OBJECT
414 OBJECT defaults to the current buffer. If there's a composition at
415 POS, set *START and *END to the start and end of the sequence,
416 *PROP to the `composition' property, and return 1.
418 If there's no composition at POS and LIMIT is negative, return 0.
420 Otherwise, search for a composition forward (LIMIT > POS) or
421 backward (LIMIT < POS). In this case, LIMIT bounds the search.
423 If a composition is found, set *START, *END, and *PROP as above,
424 and return 1, else return 0.
426 This doesn't check the validity of composition. */
429 find_composition (EMACS_INT pos
, EMACS_INT limit
,
430 EMACS_INT
*start
, EMACS_INT
*end
,
431 Lisp_Object
*prop
, Lisp_Object object
)
435 if (get_property_and_range (pos
, Qcomposition
, prop
, start
, end
, object
))
438 if (limit
< 0 || limit
== pos
)
441 if (limit
> pos
) /* search forward */
443 val
= Fnext_single_property_change (make_number (pos
), Qcomposition
,
444 object
, make_number (limit
));
449 else /* search backward */
451 if (get_property_and_range (pos
- 1, Qcomposition
, prop
, start
, end
,
454 val
= Fprevious_single_property_change (make_number (pos
), Qcomposition
,
455 object
, make_number (limit
));
461 get_property_and_range (pos
, Qcomposition
, prop
, start
, end
, object
);
465 /* Run a proper function to adjust the composition sitting between
466 FROM and TO with property PROP. */
469 run_composition_function (EMACS_INT from
, EMACS_INT to
, Lisp_Object prop
)
472 EMACS_INT start
, end
;
474 func
= COMPOSITION_MODIFICATION_FUNC (prop
);
475 /* If an invalid composition precedes or follows, try to make them
478 && find_composition (from
- 1, -1, &start
, &end
, &prop
, Qnil
)
479 && !COMPOSITION_VALID_P (start
, end
, prop
))
482 && find_composition (to
, -1, &start
, &end
, &prop
, Qnil
)
483 && !COMPOSITION_VALID_P (start
, end
, prop
))
485 if (!NILP (Ffboundp (func
)))
486 call2 (func
, make_number (from
), make_number (to
));
489 /* Make invalid compositions adjacent to or inside FROM and TO valid.
490 CHECK_MASK is bitwise `or' of mask bits defined by macros
491 CHECK_XXX (see the comment in composite.h).
493 It also resets the text-property `auto-composed' to a proper region
494 so that automatic character composition works correctly later while
495 displaying the region.
497 This function is called when a buffer text is changed. If the
498 change is deletion, FROM == TO. Otherwise, FROM < TO. */
501 update_compositions (EMACS_INT from
, EMACS_INT to
, int check_mask
)
504 EMACS_INT start
, end
;
505 /* The beginning and end of the region to set the property
506 `auto-composed' to nil. */
507 EMACS_INT min_pos
= from
, max_pos
= to
;
509 if (inhibit_modification_hooks
)
512 /* If FROM and TO are not in a valid range, do nothing. */
513 if (! (BEGV
<= from
&& from
<= to
&& to
<= ZV
))
516 if (check_mask
& CHECK_HEAD
)
518 /* FROM should be at composition boundary. But, insertion or
519 deletion will make two compositions adjacent and
520 indistinguishable when they have same (eq) property. To
521 avoid it, in such a case, we change the property of the
522 latter to the copy of it. */
524 && find_composition (from
- 1, -1, &start
, &end
, &prop
, Qnil
)
525 && COMPOSITION_VALID_P (start
, end
, prop
))
531 Fput_text_property (make_number (from
), make_number (end
),
533 Fcons (XCAR (prop
), XCDR (prop
)), Qnil
);
534 run_composition_function (start
, end
, prop
);
538 && find_composition (from
, -1, &start
, &from
, &prop
, Qnil
)
539 && COMPOSITION_VALID_P (start
, from
, prop
))
543 run_composition_function (start
, from
, prop
);
547 if (check_mask
& CHECK_INSIDE
)
549 /* In this case, we are sure that (check & CHECK_TAIL) is also
550 nonzero. Thus, here we should check only compositions before
553 && find_composition (from
, to
, &start
, &from
, &prop
, Qnil
)
554 && COMPOSITION_VALID_P (start
, from
, prop
)
556 run_composition_function (start
, from
, prop
);
559 if (check_mask
& CHECK_TAIL
)
562 && find_composition (to
- 1, -1, &start
, &end
, &prop
, Qnil
)
563 && COMPOSITION_VALID_P (start
, end
, prop
))
565 /* TO should be also at composition boundary. But,
566 insertion or deletion will make two compositions adjacent
567 and indistinguishable when they have same (eq) property.
568 To avoid it, in such a case, we change the property of
569 the former to the copy of it. */
572 Fput_text_property (make_number (start
), make_number (to
),
574 Fcons (XCAR (prop
), XCDR (prop
)), Qnil
);
577 run_composition_function (start
, end
, prop
);
580 && find_composition (to
, -1, &start
, &end
, &prop
, Qnil
)
581 && COMPOSITION_VALID_P (start
, end
, prop
))
583 run_composition_function (start
, end
, prop
);
587 if (min_pos
< max_pos
)
589 int count
= SPECPDL_INDEX ();
591 specbind (Qinhibit_read_only
, Qt
);
592 specbind (Qinhibit_modification_hooks
, Qt
);
593 specbind (Qinhibit_point_motion_hooks
, Qt
);
594 Fremove_list_of_text_properties (make_number (min_pos
),
595 make_number (max_pos
),
596 Fcons (Qauto_composed
, Qnil
), Qnil
);
597 unbind_to (count
, Qnil
);
602 /* Modify composition property values in LIST destructively. LIST is
603 a list as returned from text_property_list. Change values to the
604 top-level copies of them so that none of them are `eq'. */
607 make_composition_value_copy (Lisp_Object list
)
609 Lisp_Object plist
, val
;
611 for (; CONSP (list
); list
= XCDR (list
))
613 plist
= XCAR (XCDR (XCDR (XCAR (list
))));
614 while (CONSP (plist
) && CONSP (XCDR (plist
)))
616 if (EQ (XCAR (plist
), Qcomposition
)
617 && (val
= XCAR (XCDR (plist
)), CONSP (val
)))
618 XSETCAR (XCDR (plist
), Fcons (XCAR (val
), XCDR (val
)));
619 plist
= XCDR (XCDR (plist
));
625 /* Make text in the region between START and END a composition that
626 has COMPONENTS and MODIFICATION-FUNC.
628 If STRING is non-nil, then operate on characters contained between
629 indices START and END in STRING. */
632 compose_text (EMACS_INT start
, EMACS_INT end
, Lisp_Object components
,
633 Lisp_Object modification_func
, Lisp_Object string
)
637 prop
= Fcons (Fcons (make_number (end
- start
), components
),
639 Fput_text_property (make_number (start
), make_number (end
),
640 Qcomposition
, prop
, string
);
644 static Lisp_Object
autocmp_chars (Lisp_Object
, EMACS_INT
, EMACS_INT
,
645 EMACS_INT
, struct window
*,
646 struct face
*, Lisp_Object
);
649 /* Lisp glyph-string handlers */
651 /* Hash table for automatic composition. The key is a header of a
652 lgstring (Lispy glyph-string), and the value is a body of a
655 static Lisp_Object gstring_hash_table
;
657 static Lisp_Object
gstring_lookup_cache (Lisp_Object
);
660 gstring_lookup_cache (Lisp_Object header
)
662 struct Lisp_Hash_Table
*h
= XHASH_TABLE (gstring_hash_table
);
663 ptrdiff_t i
= hash_lookup (h
, header
, NULL
);
665 return (i
>= 0 ? HASH_VALUE (h
, i
) : Qnil
);
669 composition_gstring_put_cache (Lisp_Object gstring
, EMACS_INT len
)
671 struct Lisp_Hash_Table
*h
= XHASH_TABLE (gstring_hash_table
);
673 Lisp_Object header
, copy
;
676 header
= LGSTRING_HEADER (gstring
);
677 hash
= h
->hashfn (h
, header
);
680 EMACS_INT j
, glyph_len
= LGSTRING_GLYPH_LEN (gstring
);
681 for (j
= 0; j
< glyph_len
; j
++)
682 if (NILP (LGSTRING_GLYPH (gstring
, j
)))
687 lint_assume (len
<= TYPE_MAXIMUM (EMACS_INT
) - 2);
688 copy
= Fmake_vector (make_number (len
+ 2), Qnil
);
689 LGSTRING_SET_HEADER (copy
, Fcopy_sequence (header
));
690 for (i
= 0; i
< len
; i
++)
691 LGSTRING_SET_GLYPH (copy
, i
, Fcopy_sequence (LGSTRING_GLYPH (gstring
, i
)));
692 i
= hash_put (h
, LGSTRING_HEADER (copy
), copy
, hash
);
693 LGSTRING_SET_ID (copy
, make_number (i
));
698 composition_gstring_from_id (ptrdiff_t id
)
700 struct Lisp_Hash_Table
*h
= XHASH_TABLE (gstring_hash_table
);
702 return HASH_VALUE (h
, id
);
705 static Lisp_Object
fill_gstring_header (Lisp_Object
, Lisp_Object
,
706 Lisp_Object
, Lisp_Object
,
710 composition_gstring_p (Lisp_Object gstring
)
715 if (! VECTORP (gstring
) || ASIZE (gstring
) < 2)
717 header
= LGSTRING_HEADER (gstring
);
718 if (! VECTORP (header
) || ASIZE (header
) < 2)
720 if (! NILP (LGSTRING_FONT (gstring
))
721 && (! FONT_OBJECT_P (LGSTRING_FONT (gstring
))
722 && ! CODING_SYSTEM_P (LGSTRING_FONT (gstring
))))
724 for (i
= 1; i
< ASIZE (LGSTRING_HEADER (gstring
)); i
++)
725 if (! NATNUMP (AREF (LGSTRING_HEADER (gstring
), i
)))
727 if (! NILP (LGSTRING_ID (gstring
)) && ! NATNUMP (LGSTRING_ID (gstring
)))
729 for (i
= 0; i
< LGSTRING_GLYPH_LEN (gstring
); i
++)
731 Lisp_Object glyph
= LGSTRING_GLYPH (gstring
, i
);
734 if (! VECTORP (glyph
) || ASIZE (glyph
) != LGLYPH_SIZE
)
741 composition_gstring_width (Lisp_Object gstring
, EMACS_INT from
, EMACS_INT to
,
742 struct font_metrics
*metrics
)
749 Lisp_Object font_object
= LGSTRING_FONT (gstring
);
751 if (FONT_OBJECT_P (font_object
))
753 struct font
*font
= XFONT_OBJECT (font_object
);
755 metrics
->ascent
= font
->ascent
;
756 metrics
->descent
= font
->descent
;
761 metrics
->descent
= 0;
763 metrics
->width
= metrics
->lbearing
= metrics
->rbearing
= 0;
765 for (glyph
= &LGSTRING_GLYPH (gstring
, from
); from
< to
; from
++, glyph
++)
769 if (NILP (LGLYPH_ADJUSTMENT (*glyph
)))
770 width
+= LGLYPH_WIDTH (*glyph
);
772 width
+= LGLYPH_WADJUST (*glyph
);
775 x
= metrics
->width
+ LGLYPH_LBEARING (*glyph
) + LGLYPH_XOFF (*glyph
);
776 if (metrics
->lbearing
> x
)
777 metrics
->lbearing
= x
;
778 x
= metrics
->width
+ LGLYPH_RBEARING (*glyph
) + LGLYPH_XOFF (*glyph
);
779 if (metrics
->rbearing
< x
)
780 metrics
->rbearing
= x
;
781 metrics
->width
= width
;
782 x
= LGLYPH_ASCENT (*glyph
) - LGLYPH_YOFF (*glyph
);
783 if (metrics
->ascent
< x
)
785 x
= LGLYPH_DESCENT (*glyph
) + LGLYPH_YOFF (*glyph
);
786 if (metrics
->descent
< x
)
787 metrics
->descent
= x
;
794 static Lisp_Object gstring_work
;
795 static Lisp_Object gstring_work_headers
;
798 fill_gstring_header (Lisp_Object header
, Lisp_Object start
, Lisp_Object end
, Lisp_Object font_object
, Lisp_Object string
)
800 EMACS_INT from
, to
, from_byte
;
805 if (NILP (BVAR (current_buffer
, enable_multibyte_characters
)))
806 error ("Attempt to shape unibyte text");
807 validate_region (&start
, &end
);
808 from
= XFASTINT (start
);
810 from_byte
= CHAR_TO_BYTE (from
);
814 CHECK_STRING (string
);
815 if (! STRING_MULTIBYTE (string
))
816 error ("Attempt to shape unibyte text");
817 /* FROM and TO are checked by the caller. */
820 if (from
< 0 || from
> to
|| to
> SCHARS (string
))
821 args_out_of_range_3 (string
, start
, end
);
822 from_byte
= string_char_to_byte (string
, from
);
827 error ("Attempt to shape zero-length text");
828 if (VECTORP (header
))
830 if (ASIZE (header
) != len
+ 1)
831 args_out_of_range (header
, make_number (len
+ 1));
836 header
= AREF (gstring_work_headers
, len
- 1);
838 header
= Fmake_vector (make_number (len
+ 1), Qnil
);
841 ASET (header
, 0, font_object
);
842 for (i
= 0; i
< len
; i
++)
847 FETCH_CHAR_ADVANCE_NO_CHECK (c
, from
, from_byte
);
849 FETCH_STRING_CHAR_ADVANCE_NO_CHECK (c
, string
, from
, from_byte
);
850 ASET (header
, i
+ 1, make_number (c
));
856 fill_gstring_body (Lisp_Object gstring
)
858 Lisp_Object font_object
= LGSTRING_FONT (gstring
);
859 Lisp_Object header
= AREF (gstring
, 0);
860 EMACS_INT len
= LGSTRING_CHAR_LEN (gstring
);
863 for (i
= 0; i
< len
; i
++)
865 Lisp_Object g
= LGSTRING_GLYPH (gstring
, i
);
866 int c
= XFASTINT (AREF (header
, i
+ 1));
871 LGSTRING_SET_GLYPH (gstring
, i
, g
);
873 LGLYPH_SET_FROM (g
, i
);
874 LGLYPH_SET_TO (g
, i
);
875 LGLYPH_SET_CHAR (g
, c
);
876 if (FONT_OBJECT_P (font_object
))
878 font_fill_lglyph_metrics (g
, font_object
);
882 int width
= XFASTINT (CHAR_TABLE_REF (Vchar_width_table
, c
));
884 LGLYPH_SET_CODE (g
, c
);
885 LGLYPH_SET_LBEARING (g
, 0);
886 LGLYPH_SET_RBEARING (g
, width
);
887 LGLYPH_SET_WIDTH (g
, width
);
888 LGLYPH_SET_ASCENT (g
, 1);
889 LGLYPH_SET_DESCENT (g
, 0);
891 LGLYPH_SET_ADJUSTMENT (g
, Qnil
);
893 if (i
< LGSTRING_GLYPH_LEN (gstring
))
894 LGSTRING_SET_GLYPH (gstring
, i
, Qnil
);
898 /* Try to compose the characters at CHARPOS according to composition
899 rule RULE ([PATTERN PREV-CHARS FUNC]). LIMIT limits the characters
900 to compose. STRING, if not nil, is a target string. WIN is a
901 window where the characters are being displayed. If characters are
902 successfully composed, return the composition as a glyph-string
903 object. Otherwise return nil. */
906 autocmp_chars (Lisp_Object rule
, EMACS_INT charpos
, EMACS_INT bytepos
, EMACS_INT limit
, struct window
*win
, struct face
*face
, Lisp_Object string
)
908 int count
= SPECPDL_INDEX ();
909 FRAME_PTR f
= XFRAME (win
->frame
);
910 Lisp_Object pos
= make_number (charpos
);
912 EMACS_INT pt
= PT
, pt_byte
= PT_BYTE
;
913 Lisp_Object re
, font_object
, lgstring
;
916 record_unwind_save_match_data ();
920 else if (! STRINGP (re
))
921 return unbind_to (count
, Qnil
);
922 else if ((len
= fast_looking_at (re
, charpos
, bytepos
, limit
, -1, string
))
926 len
= BYTE_TO_CHAR (bytepos
+ len
) - charpos
;
928 len
= string_byte_to_char (string
, bytepos
+ len
) - charpos
;
931 return unbind_to (count
, Qnil
);
932 to
= limit
= charpos
+ len
;
933 #ifdef HAVE_WINDOW_SYSTEM
934 if (FRAME_WINDOW_P (f
))
936 font_object
= font_range (charpos
, &to
, win
, face
, string
);
937 if (! FONT_OBJECT_P (font_object
)
940 && (fast_looking_at (re
, charpos
, bytepos
, to
, -1, string
) <= 0)))
941 return unbind_to (count
, Qnil
);
944 #endif /* not HAVE_WINDOW_SYSTEM */
945 font_object
= win
->frame
;
946 lgstring
= Fcomposition_get_gstring (pos
, make_number (to
), font_object
,
948 if (NILP (LGSTRING_ID (lgstring
)))
952 /* Save point as marker before calling out to lisp. */
955 Lisp_Object m
= Fmake_marker ();
956 set_marker_both (m
, Qnil
, pt
, pt_byte
);
957 record_unwind_protect (restore_point_unwind
, m
);
960 args
[0] = Vauto_composition_function
;
961 args
[1] = AREF (rule
, 2);
963 args
[3] = make_number (to
);
964 args
[4] = font_object
;
966 lgstring
= safe_call (6, args
);
968 TEMP_SET_PT_BOTH (pt
, pt_byte
);
970 return unbind_to (count
, lgstring
);
973 static Lisp_Object _work_val
;
975 /* 1 iff the character C is composable. Characters of general
976 category Z? or C? are not composable except for ZWNJ and ZWJ. */
978 #define CHAR_COMPOSABLE_P(C) \
980 && ((C) == 0x200C || (C) == 0x200D \
981 || (_work_val = CHAR_TABLE_REF (Vunicode_category_table, (C)), \
982 (INTEGERP (_work_val) \
983 && (XINT (_work_val) <= UNICODE_CATEGORY_So)))))
985 /* Update cmp_it->stop_pos to the next position after CHARPOS (and
986 BYTEPOS) where character composition may happen. If BYTEPOS is
987 negative, compute it. ENDPOS is a limit of searching. If it is
988 less than CHARPOS, search backward to ENDPOS+1 assuming that
989 set_iterator_to_next works in reverse order. In this case, if a
990 composition closest to CHARPOS is found, set cmp_it->stop_pos to
991 the last character of the composition.
993 If no composition is found, set cmp_it->ch to -2. If a static
994 composition is found, set cmp_it->ch to -1. Otherwise, set
995 cmp_it->ch to the character that triggers the automatic
999 composition_compute_stop_pos (struct composition_it
*cmp_it
, EMACS_INT charpos
, EMACS_INT bytepos
, EMACS_INT endpos
, Lisp_Object string
)
1001 EMACS_INT start
, end
;
1003 Lisp_Object prop
, val
;
1004 /* This is from forward_to_next_line_start in xdisp.c. */
1005 const int MAX_NEWLINE_DISTANCE
= 500;
1007 if (charpos
< endpos
)
1009 if (endpos
> charpos
+ MAX_NEWLINE_DISTANCE
)
1010 endpos
= charpos
+ MAX_NEWLINE_DISTANCE
;
1012 else if (endpos
< charpos
)
1014 /* We search backward for a position to check composition. */
1017 /* But we don't know where to stop the searching. */
1018 endpos
= NILP (string
) ? BEGV
- 1 : -1;
1019 /* Usually we don't reach ENDPOS because we stop searching
1020 at an uncomposable character (NL, LRE, etc). */
1025 cmp_it
->reversed_p
= 0;
1026 cmp_it
->stop_pos
= endpos
;
1027 if (charpos
== endpos
)
1029 /* FIXME: Bidi is not yet handled well in static composition. */
1030 if (charpos
< endpos
1031 && find_composition (charpos
, endpos
, &start
, &end
, &prop
, string
)
1033 && COMPOSITION_VALID_P (start
, end
, prop
))
1035 cmp_it
->stop_pos
= endpos
= start
;
1038 if (NILP (BVAR (current_buffer
, enable_multibyte_characters
))
1039 || NILP (Vauto_composition_mode
))
1044 bytepos
= CHAR_TO_BYTE (charpos
);
1046 bytepos
= string_char_to_byte (string
, charpos
);
1050 if (charpos
< endpos
)
1052 /* Forward search. */
1053 while (charpos
< endpos
)
1055 if (STRINGP (string
))
1056 FETCH_STRING_CHAR_ADVANCE (c
, string
, charpos
, bytepos
);
1058 FETCH_CHAR_ADVANCE (c
, charpos
, bytepos
);
1064 val
= CHAR_TABLE_REF (Vcomposition_function_table
, c
);
1070 for (ridx
= 0; CONSP (val
); val
= XCDR (val
), ridx
++)
1073 if (VECTORP (elt
) && ASIZE (elt
) == 3
1074 && NATNUMP (AREF (elt
, 1))
1075 && charpos
- 1 - XFASTINT (AREF (elt
, 1)) >= start
)
1080 cmp_it
->rule_idx
= ridx
;
1081 cmp_it
->lookback
= XFASTINT (AREF (elt
, 1));
1082 cmp_it
->stop_pos
= charpos
- 1 - cmp_it
->lookback
;
1088 if (charpos
== endpos
)
1090 /* We couldn't find a composition point before ENDPOS. But,
1091 some character after ENDPOS may be composed with
1092 characters before ENDPOS. So, we should stop at the safe
1094 charpos
= endpos
- MAX_AUTO_COMPOSITION_LOOKBACK
;
1095 if (charpos
< start
)
1099 else if (charpos
> endpos
)
1101 /* Search backward for a pattern that may be composed and the
1102 position of (possibly) the last character of the match is
1103 closest to (but not after) START. The reason for the last
1104 character is that set_iterator_to_next works in reverse order,
1105 and thus we must stop at the last character for composition
1109 /* Limit byte position used in fast_looking_at. This is the
1110 byte position of the character after START. */
1114 p
= BYTE_POS_ADDR (bytepos
);
1116 p
= SDATA (string
) + bytepos
;
1117 c
= STRING_CHAR_AND_LENGTH (p
, len
);
1118 limit
= bytepos
+ len
;
1119 while (CHAR_COMPOSABLE_P (c
))
1121 val
= CHAR_TABLE_REF (Vcomposition_function_table
, c
);
1125 int ridx
, back
, blen
;
1127 for (ridx
= 0; CONSP (val
); val
= XCDR (val
), ridx
++)
1130 if (VECTORP (elt
) && ASIZE (elt
) == 3
1131 && NATNUMP (AREF (elt
, 1))
1132 && charpos
- (back
= XFASTINT (AREF (elt
, 1))) > endpos
)
1134 EMACS_INT cpos
= charpos
- back
, bpos
;
1139 bpos
= (NILP (string
) ? CHAR_TO_BYTE (cpos
)
1140 : string_char_to_byte (string
, cpos
));
1141 if (STRINGP (AREF (elt
, 0)))
1142 blen
= fast_looking_at (AREF (elt
, 0), cpos
, bpos
,
1143 start
+ 1, limit
, string
);
1148 /* Make CPOS point to the last character of
1149 match. Note that BLEN is byte-length. */
1154 cpos
= BYTE_TO_CHAR (bpos
) - 1;
1156 cpos
= string_byte_to_char (string
, bpos
) - 1;
1158 back
= cpos
- (charpos
- back
);
1159 if (cmp_it
->stop_pos
< cpos
1160 || (cmp_it
->stop_pos
== cpos
1161 && cmp_it
->lookback
< back
))
1163 cmp_it
->rule_idx
= ridx
;
1164 cmp_it
->stop_pos
= cpos
;
1166 cmp_it
->lookback
= back
;
1167 cmp_it
->nchars
= back
+ 1;
1173 if (charpos
- 1 == endpos
)
1175 if (STRINGP (string
))
1178 while (! CHAR_HEAD_P (*p
))
1184 DEC_BOTH (charpos
, bytepos
);
1185 p
= BYTE_POS_ADDR (bytepos
);
1187 c
= STRING_CHAR (p
);
1189 if (cmp_it
->ch
>= 0)
1190 /* We found a position to check. */
1192 /* Skip all uncomposable characters. */
1195 while (charpos
- 1 > endpos
&& ! CHAR_COMPOSABLE_P (c
))
1197 DEC_BOTH (charpos
, bytepos
);
1198 c
= FETCH_MULTIBYTE_CHAR (bytepos
);
1203 while (charpos
- 1 > endpos
&& ! CHAR_COMPOSABLE_P (c
))
1206 while (! CHAR_HEAD_P (*p
))
1209 c
= STRING_CHAR (p
);
1213 cmp_it
->stop_pos
= charpos
;
1216 /* Check if the character at CHARPOS (and BYTEPOS) is composed
1217 (possibly with the following characters) on window W. ENDPOS limits
1218 characters to be composed. FACE, in non-NULL, is a base face of
1219 the character. If STRING is not nil, it is a string containing the
1220 character to check, and CHARPOS and BYTEPOS are indices in the
1221 string. In that case, FACE must not be NULL.
1223 If the character is composed, setup members of CMP_IT (id, nglyphs,
1224 from, to, reversed_p), and return 1. Otherwise, update
1225 CMP_IT->stop_pos, and return 0. */
1228 composition_reseat_it (struct composition_it
*cmp_it
, EMACS_INT charpos
, EMACS_INT bytepos
, EMACS_INT endpos
, struct window
*w
, struct face
*face
, Lisp_Object string
)
1231 endpos
= NILP (string
) ? BEGV
: 0;
1233 if (cmp_it
->ch
== -2)
1235 composition_compute_stop_pos (cmp_it
, charpos
, bytepos
, endpos
, string
);
1236 if (cmp_it
->ch
== -2 || cmp_it
->stop_pos
!= charpos
)
1237 /* The current position is not composed. */
1243 /* We are looking at a static composition. */
1244 EMACS_INT start
, end
;
1247 find_composition (charpos
, -1, &start
, &end
, &prop
, string
);
1248 cmp_it
->id
= get_composition_id (charpos
, bytepos
, end
- start
,
1251 goto no_composition
;
1252 cmp_it
->nchars
= end
- start
;
1253 cmp_it
->nglyphs
= composition_table
[cmp_it
->id
]->glyph_len
;
1257 Lisp_Object lgstring
= Qnil
;
1258 Lisp_Object val
, elt
;
1261 val
= CHAR_TABLE_REF (Vcomposition_function_table
, cmp_it
->ch
);
1262 for (i
= 0; i
< cmp_it
->rule_idx
; i
++, val
= XCDR (val
));
1263 if (charpos
< endpos
)
1265 for (; CONSP (val
); val
= XCDR (val
))
1268 if (! VECTORP (elt
) || ASIZE (elt
) != 3
1269 || ! INTEGERP (AREF (elt
, 1)))
1271 if (XFASTINT (AREF (elt
, 1)) != cmp_it
->lookback
)
1272 goto no_composition
;
1273 lgstring
= autocmp_chars (elt
, charpos
, bytepos
, endpos
,
1275 if (composition_gstring_p (lgstring
))
1278 /* Composition failed perhaps because the font doesn't
1279 support sufficient range of characters. Try the
1280 other composition rules if any. */
1282 cmp_it
->reversed_p
= 0;
1286 EMACS_INT cpos
= charpos
, bpos
= bytepos
;
1291 if (cmp_it
->lookback
> 0)
1293 cpos
= charpos
- cmp_it
->lookback
;
1294 if (STRINGP (string
))
1295 bpos
= string_char_to_byte (string
, cpos
);
1297 bpos
= CHAR_TO_BYTE (cpos
);
1299 lgstring
= autocmp_chars (elt
, cpos
, bpos
, charpos
+ 1, w
, face
,
1301 if (composition_gstring_p (lgstring
)
1302 && cpos
+ LGSTRING_CHAR_LEN (lgstring
) - 1 == charpos
)
1304 /* Composition failed or didn't cover the current
1306 if (cmp_it
->lookback
== 0)
1307 goto no_composition
;
1309 /* Try to find a shorter compostion that starts after CPOS. */
1310 composition_compute_stop_pos (cmp_it
, charpos
, bytepos
, cpos
,
1312 if (cmp_it
->ch
== -2 || cmp_it
->stop_pos
< charpos
)
1313 goto no_composition
;
1314 val
= CHAR_TABLE_REF (Vcomposition_function_table
, cmp_it
->ch
);
1315 for (i
= 0; i
< cmp_it
->rule_idx
; i
++, val
= XCDR (val
));
1317 cmp_it
->reversed_p
= 1;
1319 if (NILP (lgstring
))
1320 goto no_composition
;
1321 if (NILP (LGSTRING_ID (lgstring
)))
1322 lgstring
= composition_gstring_put_cache (lgstring
, -1);
1323 cmp_it
->id
= XINT (LGSTRING_ID (lgstring
));
1324 for (i
= 0; i
< LGSTRING_GLYPH_LEN (lgstring
); i
++)
1325 if (NILP (LGSTRING_GLYPH (lgstring
, i
)))
1327 cmp_it
->nglyphs
= i
;
1332 goto no_composition
;
1336 if (charpos
== endpos
)
1338 if (charpos
< endpos
)
1344 bytepos
+= BYTES_BY_CHAR_HEAD (*(SDATA (string
) + bytepos
));
1349 /* BYTEPOS is calculated in composition_compute_stop_pos */
1352 composition_compute_stop_pos (cmp_it
, charpos
, bytepos
, endpos
, string
);
1356 /* Update charpos, nchars, nbytes, and width of the current grapheme
1359 If the composition is static or automatic in L2R context, the
1360 cluster is identified by CMP_IT->from, and CHARPOS is the position
1361 of the first character of the cluster. In this case, update
1364 If the composition is automatic in R2L context, the cluster is
1365 identified by CMP_IT->to, and CHARPOS is the position of the last
1366 character of the cluster. In this case, update CMP_IT->from too.
1368 The return value is the character code of the first character of
1369 the cluster, or -1 if the composition is somehow broken. */
1372 composition_update_it (struct composition_it
*cmp_it
, EMACS_INT charpos
, EMACS_INT bytepos
, Lisp_Object string
)
1374 int i
, c
IF_LINT (= 0);
1378 /* static composition */
1379 struct composition
*cmp
= composition_table
[cmp_it
->id
];
1381 cmp_it
->charpos
= charpos
;
1382 cmp_it
->to
= cmp_it
->nglyphs
;
1383 if (cmp_it
->nglyphs
== 0)
1387 for (i
= 0; i
< cmp
->glyph_len
; i
++)
1388 if ((c
= COMPOSITION_GLYPH (cmp
, i
)) != '\t')
1393 cmp_it
->width
= cmp
->width
;
1394 charpos
+= cmp_it
->nchars
;
1395 if (STRINGP (string
))
1396 cmp_it
->nbytes
= string_char_to_byte (string
, charpos
) - bytepos
;
1398 cmp_it
->nbytes
= CHAR_TO_BYTE (charpos
) - bytepos
;
1402 /* automatic composition */
1403 Lisp_Object gstring
= composition_gstring_from_id (cmp_it
->id
);
1407 if (cmp_it
->nglyphs
== 0)
1409 cmp_it
->nchars
= LGSTRING_CHAR_LEN (gstring
);
1411 cmp_it
->from
= cmp_it
->to
= 0;
1414 if (! cmp_it
->reversed_p
)
1416 glyph
= LGSTRING_GLYPH (gstring
, cmp_it
->from
);
1417 from
= LGLYPH_FROM (glyph
);
1418 for (cmp_it
->to
= cmp_it
->from
+ 1; cmp_it
->to
< cmp_it
->nglyphs
;
1421 glyph
= LGSTRING_GLYPH (gstring
, cmp_it
->to
);
1422 if (LGLYPH_FROM (glyph
) != from
)
1425 cmp_it
->charpos
= charpos
;
1429 glyph
= LGSTRING_GLYPH (gstring
, cmp_it
->to
- 1);
1430 from
= LGLYPH_FROM (glyph
);
1431 cmp_it
->charpos
= charpos
- (LGLYPH_TO (glyph
) - from
);
1432 for (cmp_it
->from
= cmp_it
->to
- 1; cmp_it
->from
> 0;
1435 glyph
= LGSTRING_GLYPH (gstring
, cmp_it
->from
- 1);
1436 if (LGLYPH_FROM (glyph
) != from
)
1440 glyph
= LGSTRING_GLYPH (gstring
, cmp_it
->from
);
1441 cmp_it
->nchars
= LGLYPH_TO (glyph
) + 1 - from
;
1444 for (i
= cmp_it
->nchars
- 1; i
>= 0; i
--)
1446 c
= XINT (LGSTRING_CHAR (gstring
, i
));
1447 cmp_it
->nbytes
+= CHAR_BYTES (c
);
1448 cmp_it
->width
+= CHAR_WIDTH (c
);
1455 struct position_record
1457 EMACS_INT pos
, pos_byte
;
1461 /* Update the members of POSITION to the next character boundary. */
1462 #define FORWARD_CHAR(POSITION, STOP) \
1465 if ((POSITION).pos == (STOP)) \
1467 (POSITION).p = GAP_END_ADDR; \
1468 (POSITION).pos_byte = GPT_BYTE; \
1472 (POSITION).pos_byte += BYTES_BY_CHAR_HEAD (*((POSITION).p)); \
1473 (POSITION).p += BYTES_BY_CHAR_HEAD (*((POSITION).p)); \
1477 /* Update the members of POSITION to the previous character boundary. */
1478 #define BACKWARD_CHAR(POSITION, STOP) \
1480 if ((POSITION).pos == (STOP)) \
1481 (POSITION).p = GPT_ADDR; \
1483 (POSITION).pos_byte--; \
1485 } while (! CHAR_HEAD_P (*((POSITION).p))); \
1489 /* This is like find_composition, but find an automatic composition
1490 instead. It is assured that POS is not within a static
1491 composition. If found, set *GSTRING to the glyph-string
1492 representing the composition, and return 1. Otherwise, *GSTRING to
1493 Qnil, and return 0. */
1496 find_automatic_composition (EMACS_INT pos
, EMACS_INT limit
,
1497 EMACS_INT
*start
, EMACS_INT
*end
,
1498 Lisp_Object
*gstring
, Lisp_Object string
)
1500 EMACS_INT head
, tail
, stop
;
1501 /* Forward limit position of checking a composition taking a
1502 looking-back count into account. */
1503 EMACS_INT fore_check_limit
;
1504 struct position_record cur
, prev
;
1508 int need_adjustment
= 0;
1510 window
= Fget_buffer_window (Fcurrent_buffer (), Qnil
);
1513 w
= XWINDOW (window
);
1518 head
= BEGV
, tail
= ZV
, stop
= GPT
;
1519 cur
.pos_byte
= CHAR_TO_BYTE (cur
.pos
);
1520 cur
.p
= BYTE_POS_ADDR (cur
.pos_byte
);
1524 head
= 0, tail
= SCHARS (string
), stop
= -1;
1525 cur
.pos_byte
= string_char_to_byte (string
, cur
.pos
);
1526 cur
.p
= SDATA (string
) + cur
.pos_byte
;
1529 /* Finding a composition covering the character after POS is the
1530 same as setting LIMIT to POS. */
1533 fore_check_limit
= min (tail
, pos
+ 1 + MAX_AUTO_COMPOSITION_LOOKBACK
);
1535 fore_check_limit
= min (tail
, limit
+ MAX_AUTO_COMPOSITION_LOOKBACK
);
1537 /* Provided that we have these possible compositions now:
1539 POS: 1 2 3 4 5 6 7 8 9
1543 Here, it is known that characters after positions 1 and 9 can
1544 never be composed (i.e. ! CHAR_COMPOSABLE_P (CH)), and
1545 composition A is an invalid one because it's partially covered by
1546 the valid composition C. And to know whether a composition is
1547 valid or not, the only way is to start searching forward from a
1548 position that can not be a tail part of composition (it's 2 in
1551 Now we have these cases (1 through 4):
1553 -- character after POS is ... --
1554 not composable composable
1555 LIMIT <= POS (1) (3)
1558 Among them, in case (2), we simply search forward from POS.
1560 In the other cases, we at first rewind back to the position where
1561 the previous character is not composable or the beginning of
1562 buffer (string), then search compositions forward. In case (1)
1563 and (3) we repeat this process until a composition is found. */
1567 c
= STRING_CHAR (cur
.p
);
1568 if (! CHAR_COMPOSABLE_P (c
))
1570 if (limit
<= pos
) /* case (1) */
1573 if (cur
.pos
<= limit
)
1575 BACKWARD_CHAR (cur
, stop
);
1576 c
= STRING_CHAR (cur
.p
);
1577 } while (! CHAR_COMPOSABLE_P (c
));
1578 fore_check_limit
= cur
.pos
+ 1;
1581 /* No need of rewinding back. */
1582 goto search_forward
;
1585 /* Rewind back to the position where we can safely search
1586 forward for compositions. It is assured that the character
1587 at cur.pos is composable. */
1588 while (head
< cur
.pos
)
1591 BACKWARD_CHAR (cur
, stop
);
1592 c
= STRING_CHAR (cur
.p
);
1593 if (! CHAR_COMPOSABLE_P (c
))
1601 /* Now search forward. */
1603 prev
= cur
; /* remember the start of searching position. */
1604 while (cur
.pos
< fore_check_limit
)
1608 c
= STRING_CHAR (cur
.p
);
1609 for (val
= CHAR_TABLE_REF (Vcomposition_function_table
, c
);
1610 CONSP (val
); val
= XCDR (val
))
1612 Lisp_Object elt
= XCAR (val
);
1614 if (VECTORP (elt
) && ASIZE (elt
) == 3 && NATNUMP (AREF (elt
, 1)))
1616 EMACS_INT check_pos
= cur
.pos
- XFASTINT (AREF (elt
, 1));
1617 struct position_record check
;
1619 if (check_pos
< head
1620 || (limit
<= pos
? pos
< check_pos
1621 : limit
<= check_pos
))
1623 for (check
= cur
; check_pos
< check
.pos
; )
1624 BACKWARD_CHAR (check
, stop
);
1625 *gstring
= autocmp_chars (elt
, check
.pos
, check
.pos_byte
,
1626 tail
, w
, NULL
, string
);
1627 need_adjustment
= 1;
1628 if (NILP (*gstring
))
1630 /* As we have called Lisp, there's a possibility
1631 that buffer/string is relocated. */
1633 cur
.p
= BYTE_POS_ADDR (cur
.pos_byte
);
1635 cur
.p
= SDATA (string
) + cur
.pos_byte
;
1639 /* We found a candidate of a target composition. */
1641 *end
= check
.pos
+ LGSTRING_CHAR_LEN (*gstring
);
1644 : *start
<= pos
&& pos
< *end
)
1645 /* This is the target composition. */
1650 cur
.pos_byte
= CHAR_TO_BYTE (cur
.pos
);
1651 cur
.p
= BYTE_POS_ADDR (cur
.pos_byte
);
1655 cur
.pos_byte
= string_char_to_byte (string
, cur
.pos
);
1656 cur
.p
= SDATA (string
) + cur
.pos_byte
;
1663 /* We found no composition here. */
1664 FORWARD_CHAR (cur
, stop
);
1667 if (pos
< limit
) /* case (2) and (4)*/
1669 if (! NILP (*gstring
))
1671 if (prev
.pos
== head
)
1674 if (need_adjustment
)
1677 cur
.p
= BYTE_POS_ADDR (cur
.pos_byte
);
1679 cur
.p
= SDATA (string
) + cur
.pos_byte
;
1681 BACKWARD_CHAR (cur
, stop
);
1685 /* Return the adjusted point provided that point is moved from LAST_PT
1689 composition_adjust_point (EMACS_INT last_pt
, EMACS_INT new_pt
)
1691 EMACS_INT i
, beg
, end
;
1694 if (new_pt
== BEGV
|| new_pt
== ZV
)
1697 /* At first check the static composition. */
1698 if (get_property_and_range (new_pt
, Qcomposition
, &val
, &beg
, &end
, Qnil
)
1699 && COMPOSITION_VALID_P (beg
, end
, val
))
1701 if (beg
< new_pt
/* && end > new_pt <- It's always the case. */
1702 && (last_pt
<= beg
|| last_pt
>= end
))
1703 return (new_pt
< last_pt
? beg
: end
);
1707 if (NILP (BVAR (current_buffer
, enable_multibyte_characters
))
1708 || NILP (Vauto_composition_mode
))
1711 /* Next check the automatic composition. */
1712 if (! find_automatic_composition (new_pt
, (EMACS_INT
) -1, &beg
, &end
, &val
,
1716 for (i
= 0; i
< LGSTRING_GLYPH_LEN (val
); i
++)
1718 Lisp_Object glyph
= LGSTRING_GLYPH (val
, i
);
1722 if (beg
+ LGLYPH_FROM (glyph
) == new_pt
)
1724 if (beg
+ LGLYPH_TO (glyph
) >= new_pt
)
1725 return (new_pt
< last_pt
1726 ? beg
+ LGLYPH_FROM (glyph
)
1727 : beg
+ LGLYPH_TO (glyph
) + 1);
1732 DEFUN ("composition-get-gstring", Fcomposition_get_gstring
,
1733 Scomposition_get_gstring
, 4, 4, 0,
1734 doc
: /* Return a glyph-string for characters between FROM and TO.
1735 If the glyph string is for graphic display, FONT-OBJECT must be
1736 a font-object to use for those characters.
1737 Otherwise (for terminal display), FONT-OBJECT must be a terminal ID, a
1738 frame, or nil for the selected frame's terminal device.
1740 If the optional 4th argument STRING is not nil, it is a string
1741 containing the target characters between indices FROM and TO.
1743 A glyph-string is a vector containing information about how to display
1744 a specific character sequence. The format is:
1745 [HEADER ID GLYPH ...]
1747 HEADER is a vector of this form:
1748 [FONT-OBJECT CHAR ...]
1750 FONT-OBJECT is a font-object for all glyphs in the glyph-string,
1751 or the terminal coding system of the specified terminal.
1752 CHARs are characters to be composed by GLYPHs.
1754 ID is an identification number of the glyph-string. It may be nil if
1757 GLYPH is a vector whose elements have this form:
1758 [ FROM-IDX TO-IDX C CODE WIDTH LBEARING RBEARING ASCENT DESCENT
1759 [ [X-OFF Y-OFF WADJUST] | nil] ]
1761 FROM-IDX and TO-IDX are used internally and should not be touched.
1762 C is the character of the glyph.
1763 CODE is the glyph-code of C in FONT-OBJECT.
1764 WIDTH thru DESCENT are the metrics (in pixels) of the glyph.
1765 X-OFF and Y-OFF are offsets to the base position for the glyph.
1766 WADJUST is the adjustment to the normal width of the glyph.
1768 If GLYPH is nil, the remaining elements of the glyph-string vector
1769 should be ignored. */)
1770 (Lisp_Object from
, Lisp_Object to
, Lisp_Object font_object
, Lisp_Object string
)
1772 Lisp_Object gstring
, header
;
1773 EMACS_INT frompos
, topos
;
1775 CHECK_NATNUM (from
);
1777 if (! FONT_OBJECT_P (font_object
))
1779 struct coding_system
*coding
;
1780 struct terminal
*terminal
= get_terminal (font_object
, 1);
1782 coding
= ((TERMINAL_TERMINAL_CODING (terminal
)->common_flags
1783 & CODING_REQUIRE_ENCODING_MASK
)
1784 ? TERMINAL_TERMINAL_CODING (terminal
) : &safe_terminal_coding
);
1785 font_object
= CODING_ID_NAME (coding
->id
);
1788 header
= fill_gstring_header (Qnil
, from
, to
, font_object
, string
);
1789 gstring
= gstring_lookup_cache (header
);
1790 if (! NILP (gstring
))
1793 frompos
= XINT (from
);
1795 if (LGSTRING_GLYPH_LEN (gstring_work
) < topos
- frompos
)
1796 gstring_work
= Fmake_vector (make_number (topos
- frompos
+ 2), Qnil
);
1797 LGSTRING_SET_HEADER (gstring_work
, header
);
1798 LGSTRING_SET_ID (gstring_work
, Qnil
);
1799 fill_gstring_body (gstring_work
);
1800 return gstring_work
;
1804 /* Emacs Lisp APIs. */
1806 DEFUN ("compose-region-internal", Fcompose_region_internal
,
1807 Scompose_region_internal
, 2, 4, 0,
1808 doc
: /* Internal use only.
1810 Compose text in the region between START and END.
1811 Optional 3rd and 4th arguments are COMPONENTS and MODIFICATION-FUNC
1812 for the composition. See `compose-region' for more details. */)
1813 (Lisp_Object start
, Lisp_Object end
, Lisp_Object components
, Lisp_Object modification_func
)
1815 validate_region (&start
, &end
);
1816 if (!NILP (components
)
1817 && !INTEGERP (components
)
1818 && !CONSP (components
)
1819 && !STRINGP (components
))
1820 CHECK_VECTOR (components
);
1822 compose_text (XINT (start
), XINT (end
), components
, modification_func
, Qnil
);
1826 DEFUN ("compose-string-internal", Fcompose_string_internal
,
1827 Scompose_string_internal
, 3, 5, 0,
1828 doc
: /* Internal use only.
1830 Compose text between indices START and END of STRING.
1831 Optional 4th and 5th arguments are COMPONENTS and MODIFICATION-FUNC
1832 for the composition. See `compose-string' for more details. */)
1833 (Lisp_Object string
, Lisp_Object start
, Lisp_Object end
, Lisp_Object components
, Lisp_Object modification_func
)
1835 CHECK_STRING (string
);
1836 CHECK_NUMBER (start
);
1839 if (XINT (start
) < 0 ||
1840 XINT (start
) > XINT (end
)
1841 || XINT (end
) > SCHARS (string
))
1842 args_out_of_range (start
, end
);
1844 compose_text (XINT (start
), XINT (end
), components
, modification_func
, string
);
1848 DEFUN ("find-composition-internal", Ffind_composition_internal
,
1849 Sfind_composition_internal
, 4, 4, 0,
1850 doc
: /* Internal use only.
1852 Return information about composition at or nearest to position POS.
1853 See `find-composition' for more details. */)
1854 (Lisp_Object pos
, Lisp_Object limit
, Lisp_Object string
, Lisp_Object detail_p
)
1856 Lisp_Object prop
, tail
, gstring
;
1857 EMACS_INT start
, end
, from
, to
;
1860 CHECK_NUMBER_COERCE_MARKER (pos
);
1864 CHECK_NUMBER_COERCE_MARKER (limit
);
1872 CHECK_STRING (string
);
1873 if (XINT (pos
) < 0 || XINT (pos
) > SCHARS (string
))
1874 args_out_of_range (string
, pos
);
1878 if (XINT (pos
) < BEGV
|| XINT (pos
) > ZV
)
1879 args_out_of_range (Fcurrent_buffer (), pos
);
1882 if (!find_composition (from
, to
, &start
, &end
, &prop
, string
))
1884 if (!NILP (BVAR (current_buffer
, enable_multibyte_characters
))
1885 && ! NILP (Vauto_composition_mode
)
1886 && find_automatic_composition (from
, to
, &start
, &end
, &gstring
,
1888 return list3 (make_number (start
), make_number (end
), gstring
);
1891 if ((end
<= XINT (pos
) || start
> XINT (pos
)))
1895 if (find_automatic_composition (from
, to
, &s
, &e
, &gstring
, string
)
1896 && (e
<= XINT (pos
) ? e
> end
: s
< start
))
1897 return list3 (make_number (s
), make_number (e
), gstring
);
1899 if (!COMPOSITION_VALID_P (start
, end
, prop
))
1900 return Fcons (make_number (start
), Fcons (make_number (end
),
1901 Fcons (Qnil
, Qnil
)));
1902 if (NILP (detail_p
))
1903 return Fcons (make_number (start
), Fcons (make_number (end
),
1906 if (COMPOSITION_REGISTERD_P (prop
))
1907 id
= COMPOSITION_ID (prop
);
1910 EMACS_INT start_byte
= (NILP (string
)
1911 ? CHAR_TO_BYTE (start
)
1912 : string_char_to_byte (string
, start
));
1913 id
= get_composition_id (start
, start_byte
, end
- start
, prop
, string
);
1918 Lisp_Object components
, relative_p
, mod_func
;
1919 enum composition_method method
= COMPOSITION_METHOD (prop
);
1920 int width
= composition_table
[id
]->width
;
1922 components
= Fcopy_sequence (COMPOSITION_COMPONENTS (prop
));
1923 relative_p
= (method
== COMPOSITION_WITH_RULE_ALTCHARS
1925 mod_func
= COMPOSITION_MODIFICATION_FUNC (prop
);
1926 tail
= Fcons (components
,
1929 Fcons (make_number (width
), Qnil
))));
1934 return Fcons (make_number (start
), Fcons (make_number (end
), tail
));
1939 syms_of_composite (void)
1943 DEFSYM (Qcomposition
, "composition");
1945 /* Make a hash table for static composition. */
1947 Lisp_Object args
[6];
1951 args
[2] = QCweakness
;
1952 /* We used to make the hash table weak so that unreferenced
1953 compositions can be garbage-collected. But, usually once
1954 created compositions are repeatedly used in an Emacs session,
1955 and thus it's not worth to save memory in such a way. So, we
1956 make the table not weak. */
1959 args
[5] = make_number (311);
1960 composition_hash_table
= Fmake_hash_table (6, args
);
1961 staticpro (&composition_hash_table
);
1964 /* Make a hash table for glyph-string. */
1966 Lisp_Object args
[6];
1969 args
[2] = QCweakness
;
1972 args
[5] = make_number (311);
1973 gstring_hash_table
= Fmake_hash_table (6, args
);
1974 staticpro (&gstring_hash_table
);
1977 staticpro (&gstring_work_headers
);
1978 gstring_work_headers
= Fmake_vector (make_number (8), Qnil
);
1979 for (i
= 0; i
< 8; i
++)
1980 ASET (gstring_work_headers
, i
, Fmake_vector (make_number (i
+ 2), Qnil
));
1981 staticpro (&gstring_work
);
1982 gstring_work
= Fmake_vector (make_number (10), Qnil
);
1984 /* Text property `composition' should be nonsticky by default. */
1985 Vtext_property_default_nonsticky
1986 = Fcons (Fcons (Qcomposition
, Qt
), Vtext_property_default_nonsticky
);
1988 DEFVAR_LISP ("compose-chars-after-function", Vcompose_chars_after_function
,
1989 doc
: /* Function to adjust composition of buffer text.
1991 This function is called with three arguments: FROM, TO, and OBJECT.
1992 FROM and TO specify the range of text whose composition should be
1993 adjusted. OBJECT, if non-nil, is a string that contains the text.
1995 This function is called after a text with `composition' property is
1996 inserted or deleted to keep `composition' property of buffer text
1999 The default value is the function `compose-chars-after'. */);
2000 Vcompose_chars_after_function
= intern_c_string ("compose-chars-after");
2002 DEFSYM (Qauto_composed
, "auto-composed");
2003 DEFSYM (Qauto_composition_function
, "auto-composition-function");
2005 DEFVAR_LISP ("auto-composition-mode", Vauto_composition_mode
,
2006 doc
: /* Non-nil if Auto-Composition mode is enabled.
2007 Use the command `auto-composition-mode' to change this variable. */);
2008 Vauto_composition_mode
= Qt
;
2010 DEFVAR_LISP ("auto-composition-function", Vauto_composition_function
,
2011 doc
: /* Function to call to compose characters automatically.
2012 This function is called from the display routine with four arguments:
2013 FROM, TO, WINDOW, and STRING.
2015 If STRING is nil, the function must compose characters in the region
2016 between FROM and TO in the current buffer.
2018 Otherwise, STRING is a string, and FROM and TO are indices into the
2019 string. In this case, the function must compose characters in the
2021 Vauto_composition_function
= Qnil
;
2023 DEFVAR_LISP ("composition-function-table", Vcomposition_function_table
,
2024 doc
: /* Char-table of functions for automatic character composition.
2025 For each character that has to be composed automatically with
2026 preceding and/or following characters, this char-table contains
2027 a function to call to compose that character.
2029 The element at index C in the table, if non-nil, is a list of
2030 composition rules of this form: ([PATTERN PREV-CHARS FUNC] ...)
2032 PATTERN is a regular expression which C and the surrounding
2033 characters must match.
2035 PREV-CHARS is a non-negative integer (less than 4) specifying how many
2036 characters before C to check the matching with PATTERN. If it is 0,
2037 PATTERN must match C and the following characters. If it is 1,
2038 PATTERN must match a character before C and the following characters.
2040 If PREV-CHARS is 0, PATTERN can be nil, which means that the
2041 single character C should be composed.
2043 FUNC is a function to return a glyph-string representing a
2044 composition of the characters that match PATTERN. It is
2045 called with one argument GSTRING.
2047 GSTRING is a template of a glyph-string to return. It is already
2048 filled with a proper header for the characters to compose, and
2049 glyphs corresponding to those characters one by one. The
2050 function must return a new glyph-string with the same header as
2051 GSTRING, or modify GSTRING itself and return it.
2053 See also the documentation of `auto-composition-mode'. */);
2054 Vcomposition_function_table
= Fmake_char_table (Qnil
, Qnil
);
2056 defsubr (&Scompose_region_internal
);
2057 defsubr (&Scompose_string_internal
);
2058 defsubr (&Sfind_composition_internal
);
2059 defsubr (&Scomposition_get_gstring
);