(cal-html-insert-link-yearpage, (cal-html-htmlify-list): Doc fix.
[emacs.git] / src / indent.c
blobb4443825c5d596ce0975cbcfd5875e0eb3899481
1 /* Indentation functions.
2 Copyright (C) 1985, 1986, 1987, 1988, 1993, 1994, 1995, 1998, 2000, 2001,
3 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GNU Emacs.
8 GNU Emacs is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs; see the file COPYING. If not, write to
20 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
23 #include <config.h>
24 #include <stdio.h>
26 #include "lisp.h"
27 #include "buffer.h"
28 #include "character.h"
29 #include "category.h"
30 #include "indent.h"
31 #include "keyboard.h"
32 #include "frame.h"
33 #include "window.h"
34 #include "termchar.h"
35 #include "termopts.h"
36 #include "disptab.h"
37 #include "intervals.h"
38 #include "region-cache.h"
40 /* Indentation can insert tabs if this is non-zero;
41 otherwise always uses spaces. */
43 static int indent_tabs_mode;
45 #define CR 015
47 /* These three values memorize the current column to avoid recalculation. */
49 /* Last value returned by current_column.
50 Some things in set last_known_column_point to -1
51 to mark the memorized value as invalid. */
53 static double last_known_column;
55 /* Value of point when current_column was called. */
57 EMACS_INT last_known_column_point;
59 /* Value of MODIFF when current_column was called. */
61 static int last_known_column_modified;
63 static double current_column_1 P_ ((void));
64 static double position_indentation P_ ((int));
66 /* Cache of beginning of line found by the last call of
67 current_column. */
69 static EMACS_INT current_column_bol_cache;
71 /* Get the display table to use for the current buffer. */
73 struct Lisp_Char_Table *
74 buffer_display_table ()
76 Lisp_Object thisbuf;
78 thisbuf = current_buffer->display_table;
79 if (DISP_TABLE_P (thisbuf))
80 return XCHAR_TABLE (thisbuf);
81 if (DISP_TABLE_P (Vstandard_display_table))
82 return XCHAR_TABLE (Vstandard_display_table);
83 return 0;
86 /* Width run cache considerations. */
88 /* Return the width of character C under display table DP. */
90 static int
91 character_width (c, dp)
92 int c;
93 struct Lisp_Char_Table *dp;
95 Lisp_Object elt;
97 /* These width computations were determined by examining the cases
98 in display_text_line. */
100 /* Everything can be handled by the display table, if it's
101 present and the element is right. */
102 if (dp && (elt = DISP_CHAR_VECTOR (dp, c), VECTORP (elt)))
103 return XVECTOR (elt)->size;
105 /* Some characters are special. */
106 if (c == '\n' || c == '\t' || c == '\015')
107 return 0;
109 /* Printing characters have width 1. */
110 else if (c >= 040 && c < 0177)
111 return 1;
113 /* Everybody else (control characters, metacharacters) has other
114 widths. We could return their actual widths here, but they
115 depend on things like ctl_arrow and crud like that, and they're
116 not very common at all. So we'll just claim we don't know their
117 widths. */
118 else
119 return 0;
122 /* Return true if the display table DISPTAB specifies the same widths
123 for characters as WIDTHTAB. We use this to decide when to
124 invalidate the buffer's width_run_cache. */
127 disptab_matches_widthtab (disptab, widthtab)
128 struct Lisp_Char_Table *disptab;
129 struct Lisp_Vector *widthtab;
131 int i;
133 if (widthtab->size != 256)
134 abort ();
136 for (i = 0; i < 256; i++)
137 if (character_width (i, disptab)
138 != XFASTINT (widthtab->contents[i]))
139 return 0;
141 return 1;
144 /* Recompute BUF's width table, using the display table DISPTAB. */
146 void
147 recompute_width_table (buf, disptab)
148 struct buffer *buf;
149 struct Lisp_Char_Table *disptab;
151 int i;
152 struct Lisp_Vector *widthtab;
154 if (!VECTORP (buf->width_table))
155 buf->width_table = Fmake_vector (make_number (256), make_number (0));
156 widthtab = XVECTOR (buf->width_table);
157 if (widthtab->size != 256)
158 abort ();
160 for (i = 0; i < 256; i++)
161 XSETFASTINT (widthtab->contents[i], character_width (i, disptab));
164 /* Allocate or free the width run cache, as requested by the current
165 state of current_buffer's cache_long_line_scans variable. */
167 static void
168 width_run_cache_on_off ()
170 if (NILP (current_buffer->cache_long_line_scans)
171 /* And, for the moment, this feature doesn't work on multibyte
172 characters. */
173 || !NILP (current_buffer->enable_multibyte_characters))
175 /* It should be off. */
176 if (current_buffer->width_run_cache)
178 free_region_cache (current_buffer->width_run_cache);
179 current_buffer->width_run_cache = 0;
180 current_buffer->width_table = Qnil;
183 else
185 /* It should be on. */
186 if (current_buffer->width_run_cache == 0)
188 current_buffer->width_run_cache = new_region_cache ();
189 recompute_width_table (current_buffer, buffer_display_table ());
195 /* Skip some invisible characters starting from POS.
196 This includes characters invisible because of text properties
197 and characters invisible because of overlays.
199 If position POS is followed by invisible characters,
200 skip some of them and return the position after them.
201 Otherwise return POS itself.
203 Set *NEXT_BOUNDARY_P to the next position at which
204 it will be necessary to call this function again.
206 Don't scan past TO, and don't set *NEXT_BOUNDARY_P
207 to a value greater than TO.
209 If WINDOW is non-nil, and this buffer is displayed in WINDOW,
210 take account of overlays that apply only in WINDOW.
212 We don't necessarily skip all the invisible characters after POS
213 because that could take a long time. We skip a reasonable number
214 which can be skipped quickly. If there might be more invisible
215 characters immediately following, then *NEXT_BOUNDARY_P
216 will equal the return value. */
218 EMACS_INT
219 skip_invisible (pos, next_boundary_p, to, window)
220 EMACS_INT pos;
221 EMACS_INT *next_boundary_p;
222 EMACS_INT to;
223 Lisp_Object window;
225 Lisp_Object prop, position, overlay_limit, proplimit;
226 Lisp_Object buffer, tmp;
227 EMACS_INT end;
228 int inv_p;
230 XSETFASTINT (position, pos);
231 XSETBUFFER (buffer, current_buffer);
233 /* Give faster response for overlay lookup near POS. */
234 recenter_overlay_lists (current_buffer, pos);
236 /* We must not advance farther than the next overlay change.
237 The overlay change might change the invisible property;
238 or there might be overlay strings to be displayed there. */
239 overlay_limit = Fnext_overlay_change (position);
240 /* As for text properties, this gives a lower bound
241 for where the invisible text property could change. */
242 proplimit = Fnext_property_change (position, buffer, Qt);
243 if (XFASTINT (overlay_limit) < XFASTINT (proplimit))
244 proplimit = overlay_limit;
245 /* PROPLIMIT is now a lower bound for the next change
246 in invisible status. If that is plenty far away,
247 use that lower bound. */
248 if (XFASTINT (proplimit) > pos + 100 || XFASTINT (proplimit) >= to)
249 *next_boundary_p = XFASTINT (proplimit);
250 /* Otherwise, scan for the next `invisible' property change. */
251 else
253 /* Don't scan terribly far. */
254 XSETFASTINT (proplimit, min (pos + 100, to));
255 /* No matter what. don't go past next overlay change. */
256 if (XFASTINT (overlay_limit) < XFASTINT (proplimit))
257 proplimit = overlay_limit;
258 tmp = Fnext_single_property_change (position, Qinvisible,
259 buffer, proplimit);
260 end = XFASTINT (tmp);
261 #if 0
262 /* Don't put the boundary in the middle of multibyte form if
263 there is no actual property change. */
264 if (end == pos + 100
265 && !NILP (current_buffer->enable_multibyte_characters)
266 && end < ZV)
267 while (pos < end && !CHAR_HEAD_P (POS_ADDR (end)))
268 end--;
269 #endif
270 *next_boundary_p = end;
272 /* if the `invisible' property is set, we can skip to
273 the next property change */
274 prop = Fget_char_property (position, Qinvisible,
275 (!NILP (window)
276 && EQ (XWINDOW (window)->buffer, buffer))
277 ? window : buffer);
278 inv_p = TEXT_PROP_MEANS_INVISIBLE (prop);
279 /* When counting columns (window == nil), don't skip over ellipsis text. */
280 if (NILP (window) ? inv_p == 1 : inv_p)
281 return *next_boundary_p;
282 return pos;
285 /* If a composition starts at POS/POS_BYTE and it doesn't stride over
286 POINT, set *LEN / *LEN_BYTE to the character and byte lengths, *WIDTH
287 to the width, and return 1. Otherwise, return 0. */
289 static int
290 check_composition (pos, pos_byte, point, len, len_byte, width)
291 int pos, pos_byte, point;
292 int *len, *len_byte, *width;
294 Lisp_Object prop;
295 EMACS_INT start, end;
296 int id;
298 if (! find_composition (pos, -1, &start, &end, &prop, Qnil)
299 || pos != start || point < end
300 || !COMPOSITION_VALID_P (start, end, prop))
301 return 0;
302 if ((id = get_composition_id (pos, pos_byte, end - pos, prop, Qnil)) < 0)
303 return 0;
305 *len = COMPOSITION_LENGTH (prop);
306 *len_byte = CHAR_TO_BYTE (end) - pos_byte;
307 *width = composition_table[id]->width;
308 return 1;
311 /* Set variables WIDTH and BYTES for a multibyte sequence starting at P.
313 DP is a display table or NULL.
315 This macro is used in current_column_1, Fmove_to_column, and
316 compute_motion. */
318 #define MULTIBYTE_BYTES_WIDTH(p, dp) \
319 do { \
320 int c; \
322 wide_column = 0; \
323 c = STRING_CHAR_AND_LENGTH (p, MAX_MULTIBYTE_LENGTH, bytes); \
324 if (BYTES_BY_CHAR_HEAD (*p) != bytes) \
325 width = bytes * 4; \
326 else \
328 if (dp != 0 && VECTORP (DISP_CHAR_VECTOR (dp, c))) \
329 width = XVECTOR (DISP_CHAR_VECTOR (dp, c))->size; \
330 else \
331 width = CHAR_WIDTH (c); \
332 if (width > 1) \
333 wide_column = width; \
335 } while (0)
338 DEFUN ("current-column", Fcurrent_column, Scurrent_column, 0, 0, 0,
339 doc: /* Return the horizontal position of point. Beginning of line is column 0.
340 This is calculated by adding together the widths of all the displayed
341 representations of the character between the start of the previous line
342 and point (eg. control characters will have a width of 2 or 4, tabs
343 will have a variable width).
344 Ignores finite width of frame, which means that this function may return
345 values greater than (frame-width).
346 Whether the line is visible (if `selective-display' is t) has no effect;
347 however, ^M is treated as end of line when `selective-display' is t.
348 Text that has an invisible property is considered as having width 0, unless
349 `buffer-invisibility-spec' specifies that it is replaced by an ellipsis. */)
352 Lisp_Object temp;
353 XSETFASTINT (temp, (int) current_column ()); /* iftc */
354 return temp;
357 /* Cancel any recorded value of the horizontal position. */
359 void
360 invalidate_current_column ()
362 last_known_column_point = 0;
365 double
366 current_column ()
368 register int col;
369 register unsigned char *ptr, *stop;
370 register int tab_seen;
371 int post_tab;
372 register int c;
373 register int tab_width = XINT (current_buffer->tab_width);
374 int ctl_arrow = !NILP (current_buffer->ctl_arrow);
375 register struct Lisp_Char_Table *dp = buffer_display_table ();
377 if (PT == last_known_column_point
378 && MODIFF == last_known_column_modified)
379 return last_known_column;
381 /* If the buffer has overlays, text properties,
382 or multibyte characters, use a more general algorithm. */
383 if (BUF_INTERVALS (current_buffer)
384 || current_buffer->overlays_before
385 || current_buffer->overlays_after
386 || Z != Z_BYTE)
387 return current_column_1 ();
389 /* Scan backwards from point to the previous newline,
390 counting width. Tab characters are the only complicated case. */
392 /* Make a pointer for decrementing through the chars before point. */
393 ptr = BYTE_POS_ADDR (PT_BYTE - 1) + 1;
394 /* Make a pointer to where consecutive chars leave off,
395 going backwards from point. */
396 if (PT == BEGV)
397 stop = ptr;
398 else if (PT <= GPT || BEGV > GPT)
399 stop = BEGV_ADDR;
400 else
401 stop = GAP_END_ADDR;
403 if (tab_width <= 0 || tab_width > 1000)
404 tab_width = 8;
406 col = 0, tab_seen = 0, post_tab = 0;
408 while (1)
410 EMACS_INT i, n;
411 Lisp_Object charvec;
413 if (ptr == stop)
415 /* We stopped either for the beginning of the buffer
416 or for the gap. */
417 if (ptr == BEGV_ADDR)
418 break;
420 /* It was the gap. Jump back over it. */
421 stop = BEGV_ADDR;
422 ptr = GPT_ADDR;
424 /* Check whether that brings us to beginning of buffer. */
425 if (BEGV >= GPT)
426 break;
429 c = *--ptr;
431 if (dp && VECTORP (DISP_CHAR_VECTOR (dp, c)))
433 charvec = DISP_CHAR_VECTOR (dp, c);
434 n = ASIZE (charvec);
436 else
438 charvec = Qnil;
439 n = 1;
442 for (i = n - 1; i >= 0; --i)
444 if (VECTORP (charvec))
446 /* This should be handled the same as
447 next_element_from_display_vector does it. */
448 Lisp_Object entry = AREF (charvec, i);
450 if (GLYPH_CODE_P (entry)
451 && GLYPH_CODE_CHAR_VALID_P (entry))
452 c = GLYPH_CODE_CHAR (entry);
453 else
454 c = ' ';
457 if (c >= 040 && c < 0177)
458 col++;
459 else if (c == '\n'
460 || (c == '\r'
461 && EQ (current_buffer->selective_display, Qt)))
463 ptr++;
464 goto start_of_line_found;
466 else if (c == '\t')
468 if (tab_seen)
469 col = ((col + tab_width) / tab_width) * tab_width;
471 post_tab += col;
472 col = 0;
473 tab_seen = 1;
475 else if (VECTORP (charvec))
476 /* With a display table entry, C is displayed as is, and
477 not displayed as \NNN or as ^N. If C is a single-byte
478 character, it takes one column. If C is multi-byte in
479 an unibyte buffer, it's translated to unibyte, so it
480 also takes one column. */
481 ++col;
482 else
483 col += (ctl_arrow && c < 0200) ? 2 : 4;
487 start_of_line_found:
489 if (tab_seen)
491 col = ((col + tab_width) / tab_width) * tab_width;
492 col += post_tab;
495 if (ptr == BEGV_ADDR)
496 current_column_bol_cache = BEGV;
497 else
498 current_column_bol_cache = BYTE_TO_CHAR (PTR_BYTE_POS (ptr));
500 last_known_column = col;
501 last_known_column_point = PT;
502 last_known_column_modified = MODIFF;
504 return col;
507 /* Return the column number of position POS
508 by scanning forward from the beginning of the line.
509 This function handles characters that are invisible
510 due to text properties or overlays. */
512 static double
513 current_column_1 ()
515 register EMACS_INT tab_width = XINT (current_buffer->tab_width);
516 register int ctl_arrow = !NILP (current_buffer->ctl_arrow);
517 register struct Lisp_Char_Table *dp = buffer_display_table ();
518 int multibyte = !NILP (current_buffer->enable_multibyte_characters);
520 /* Start the scan at the beginning of this line with column number 0. */
521 register EMACS_INT col = 0;
522 EMACS_INT scan, scan_byte;
523 EMACS_INT next_boundary;
524 EMACS_INT opoint = PT, opoint_byte = PT_BYTE;
526 scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, 1);
527 current_column_bol_cache = PT;
528 scan = PT, scan_byte = PT_BYTE;
529 SET_PT_BOTH (opoint, opoint_byte);
530 next_boundary = scan;
532 if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
534 /* Scan forward to the target position. */
535 while (scan < opoint)
537 int c;
539 /* Occasionally we may need to skip invisible text. */
540 while (scan == next_boundary)
542 int old_scan = scan;
543 /* This updates NEXT_BOUNDARY to the next place
544 where we might need to skip more invisible text. */
545 scan = skip_invisible (scan, &next_boundary, opoint, Qnil);
546 if (scan >= opoint)
547 goto endloop;
548 if (scan != old_scan)
549 scan_byte = CHAR_TO_BYTE (scan);
552 /* Check composition sequence. */
554 int len, len_byte, width;
556 if (check_composition (scan, scan_byte, opoint,
557 &len, &len_byte, &width))
559 scan += len;
560 scan_byte += len_byte;
561 if (scan <= opoint)
562 col += width;
563 continue;
567 c = FETCH_BYTE (scan_byte);
569 if (dp != 0
570 && ! (multibyte && BASE_LEADING_CODE_P (c))
571 && VECTORP (DISP_CHAR_VECTOR (dp, c)))
573 Lisp_Object charvec;
574 EMACS_INT i, n;
576 /* This character is displayed using a vector of glyphs.
577 Update the column based on those glyphs. */
579 charvec = DISP_CHAR_VECTOR (dp, c);
580 n = ASIZE (charvec);
582 for (i = 0; i < n; i++)
584 /* This should be handled the same as
585 next_element_from_display_vector does it. */
586 Lisp_Object entry = AREF (charvec, i);
588 if (GLYPH_CODE_P (entry)
589 && GLYPH_CODE_CHAR_VALID_P (entry))
590 c = GLYPH_CODE_CHAR (entry);
591 else
592 c = ' ';
594 if (c == '\n')
595 goto endloop;
596 if (c == '\r' && EQ (current_buffer->selective_display, Qt))
597 goto endloop;
598 if (c == '\t')
600 col += tab_width;
601 col = col / tab_width * tab_width;
603 else
604 ++col;
607 else
609 /* The display table says nothing for this character.
610 Display it as itself. */
612 if (c == '\n')
613 goto endloop;
614 if (c == '\r' && EQ (current_buffer->selective_display, Qt))
615 goto endloop;
616 if (c == '\t')
618 col += tab_width;
619 col = col / tab_width * tab_width;
621 else if (multibyte && BASE_LEADING_CODE_P (c))
623 unsigned char *ptr;
624 int bytes, width, wide_column;
626 ptr = BYTE_POS_ADDR (scan_byte);
627 MULTIBYTE_BYTES_WIDTH (ptr, dp);
628 scan_byte += bytes;
629 /* Subtract one to compensate for the increment
630 that is going to happen below. */
631 scan_byte--;
632 col += width;
634 else if (ctl_arrow && (c < 040 || c == 0177))
635 col += 2;
636 else if (c < 040 || c >= 0177)
637 col += 4;
638 else
639 col++;
641 scan++;
642 scan_byte++;
645 endloop:
647 last_known_column = col;
648 last_known_column_point = PT;
649 last_known_column_modified = MODIFF;
651 return col;
655 #if 0 /* Not used. */
657 /* Return the width in columns of the part of STRING from BEG to END.
658 If BEG is nil, that stands for the beginning of STRING.
659 If END is nil, that stands for the end of STRING. */
661 static double
662 string_display_width (string, beg, end)
663 Lisp_Object string, beg, end;
665 register int col;
666 register unsigned char *ptr, *stop;
667 register int tab_seen;
668 int post_tab;
669 register int c;
670 register int tab_width = XINT (current_buffer->tab_width);
671 int ctl_arrow = !NILP (current_buffer->ctl_arrow);
672 register struct Lisp_Char_Table *dp = buffer_display_table ();
673 int b, e;
675 if (NILP (end))
676 e = SCHARS (string);
677 else
679 CHECK_NUMBER (end);
680 e = XINT (end);
683 if (NILP (beg))
684 b = 0;
685 else
687 CHECK_NUMBER (beg);
688 b = XINT (beg);
691 /* Make a pointer for decrementing through the chars before point. */
692 ptr = SDATA (string) + e;
693 /* Make a pointer to where consecutive chars leave off,
694 going backwards from point. */
695 stop = SDATA (string) + b;
697 if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
699 col = 0, tab_seen = 0, post_tab = 0;
701 while (1)
703 if (ptr == stop)
704 break;
706 c = *--ptr;
707 if (dp != 0 && VECTORP (DISP_CHAR_VECTOR (dp, c)))
708 col += XVECTOR (DISP_CHAR_VECTOR (dp, c))->size;
709 else if (c >= 040 && c < 0177)
710 col++;
711 else if (c == '\n')
712 break;
713 else if (c == '\t')
715 if (tab_seen)
716 col = ((col + tab_width) / tab_width) * tab_width;
718 post_tab += col;
719 col = 0;
720 tab_seen = 1;
722 else
723 col += (ctl_arrow && c < 0200) ? 2 : 4;
726 if (tab_seen)
728 col = ((col + tab_width) / tab_width) * tab_width;
729 col += post_tab;
732 return col;
735 #endif /* 0 */
738 DEFUN ("indent-to", Findent_to, Sindent_to, 1, 2, "NIndent to column: ",
739 doc: /* Indent from point with tabs and spaces until COLUMN is reached.
740 Optional second argument MINIMUM says always do at least MINIMUM spaces
741 even if that goes past COLUMN; by default, MINIMUM is zero.
743 The return value is COLUMN. */)
744 (column, minimum)
745 Lisp_Object column, minimum;
747 int mincol;
748 register int fromcol;
749 register int tab_width = XINT (current_buffer->tab_width);
751 CHECK_NUMBER (column);
752 if (NILP (minimum))
753 XSETFASTINT (minimum, 0);
754 CHECK_NUMBER (minimum);
756 fromcol = current_column ();
757 mincol = fromcol + XINT (minimum);
758 if (mincol < XINT (column)) mincol = XINT (column);
760 if (fromcol == mincol)
761 return make_number (mincol);
763 if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
765 if (indent_tabs_mode)
767 Lisp_Object n;
768 XSETFASTINT (n, mincol / tab_width - fromcol / tab_width);
769 if (XFASTINT (n) != 0)
771 Finsert_char (make_number ('\t'), n, Qt);
773 fromcol = (mincol / tab_width) * tab_width;
777 XSETFASTINT (column, mincol - fromcol);
778 Finsert_char (make_number (' '), column, Qt);
780 last_known_column = mincol;
781 last_known_column_point = PT;
782 last_known_column_modified = MODIFF;
784 XSETINT (column, mincol);
785 return column;
789 static double position_indentation P_ ((int));
791 DEFUN ("current-indentation", Fcurrent_indentation, Scurrent_indentation,
792 0, 0, 0,
793 doc: /* Return the indentation of the current line.
794 This is the horizontal position of the character
795 following any initial whitespace. */)
798 Lisp_Object val;
799 int opoint = PT, opoint_byte = PT_BYTE;
801 scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, 1);
803 XSETFASTINT (val, (int) position_indentation (PT_BYTE)); /* iftc */
804 SET_PT_BOTH (opoint, opoint_byte);
805 return val;
808 static double
809 position_indentation (pos_byte)
810 register int pos_byte;
812 register EMACS_INT column = 0;
813 register EMACS_INT tab_width = XINT (current_buffer->tab_width);
814 register unsigned char *p;
815 register unsigned char *stop;
816 unsigned char *start;
817 EMACS_INT next_boundary_byte = pos_byte;
818 EMACS_INT ceiling = next_boundary_byte;
820 if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
822 p = BYTE_POS_ADDR (pos_byte);
823 /* STOP records the value of P at which we will need
824 to think about the gap, or about invisible text,
825 or about the end of the buffer. */
826 stop = p;
827 /* START records the starting value of P. */
828 start = p;
829 while (1)
831 while (p == stop)
833 EMACS_INT stop_pos_byte;
835 /* If we have updated P, set POS_BYTE to match.
836 The first time we enter the loop, POS_BYTE is already right. */
837 if (p != start)
838 pos_byte = PTR_BYTE_POS (p);
839 /* Consider the various reasons STOP might have been set here. */
840 if (pos_byte == ZV_BYTE)
841 return column;
842 if (pos_byte == next_boundary_byte)
844 EMACS_INT next_boundary;
845 EMACS_INT pos = BYTE_TO_CHAR (pos_byte);
846 pos = skip_invisible (pos, &next_boundary, ZV, Qnil);
847 pos_byte = CHAR_TO_BYTE (pos);
848 next_boundary_byte = CHAR_TO_BYTE (next_boundary);
850 if (pos_byte >= ceiling)
851 ceiling = BUFFER_CEILING_OF (pos_byte) + 1;
852 /* Compute the next place we need to stop and think,
853 and set STOP accordingly. */
854 stop_pos_byte = min (ceiling, next_boundary_byte);
855 /* The -1 and +1 arrange to point at the first byte of gap
856 (if STOP_POS_BYTE is the position of the gap)
857 rather than at the data after the gap. */
859 stop = BYTE_POS_ADDR (stop_pos_byte - 1) + 1;
860 p = BYTE_POS_ADDR (pos_byte);
862 switch (*p++)
864 case 0240:
865 if (! NILP (current_buffer->enable_multibyte_characters))
866 return column;
867 case ' ':
868 column++;
869 break;
870 case '\t':
871 column += tab_width - column % tab_width;
872 break;
873 default:
874 if (ASCII_BYTE_P (p[-1])
875 || NILP (current_buffer->enable_multibyte_characters))
876 return column;
878 int c;
879 pos_byte = PTR_BYTE_POS (p - 1);
880 c = FETCH_MULTIBYTE_CHAR (pos_byte);
881 if (CHAR_HAS_CATEGORY (c, ' '))
883 column++;
884 INC_POS (pos_byte);
885 p = BYTE_POS_ADDR (pos_byte);
887 else
888 return column;
894 /* Test whether the line beginning at POS is indented beyond COLUMN.
895 Blank lines are treated as if they had the same indentation as the
896 preceding line. */
899 indented_beyond_p (pos, pos_byte, column)
900 int pos, pos_byte;
901 double column;
903 double val;
904 int opoint = PT, opoint_byte = PT_BYTE;
906 SET_PT_BOTH (pos, pos_byte);
907 while (PT > BEGV && FETCH_BYTE (PT_BYTE) == '\n')
908 scan_newline (PT - 1, PT_BYTE - 1, BEGV, BEGV_BYTE, -1, 0);
910 val = position_indentation (PT_BYTE);
911 SET_PT_BOTH (opoint, opoint_byte);
912 return val >= column; /* hmm, float comparison */
915 DEFUN ("move-to-column", Fmove_to_column, Smove_to_column, 1, 2, "p",
916 doc: /* Move point to column COLUMN in the current line.
917 Interactively, COLUMN is the value of prefix numeric argument.
918 The column of a character is calculated by adding together the widths
919 as displayed of the previous characters in the line.
920 This function ignores line-continuation;
921 there is no upper limit on the column number a character can have
922 and horizontal scrolling has no effect.
924 If specified column is within a character, point goes after that character.
925 If it's past end of line, point goes to end of line.
927 Optional second argument FORCE non-nil means if COLUMN is in the
928 middle of a tab character, change it to spaces.
929 In addition, if FORCE is t, and the line is too short to reach
930 COLUMN, add spaces/tabs to get there.
932 The return value is the current column. */)
933 (column, force)
934 Lisp_Object column, force;
936 register EMACS_INT pos;
937 register EMACS_INT col = current_column ();
938 register EMACS_INT goal;
939 register EMACS_INT end;
940 register int tab_width = XINT (current_buffer->tab_width);
941 register int ctl_arrow = !NILP (current_buffer->ctl_arrow);
942 register struct Lisp_Char_Table *dp = buffer_display_table ();
943 register int multibyte = !NILP (current_buffer->enable_multibyte_characters);
945 Lisp_Object val;
946 EMACS_INT prev_col = 0;
947 int c = 0;
948 EMACS_INT next_boundary, pos_byte;
950 if (tab_width <= 0 || tab_width > 1000) tab_width = 8;
951 CHECK_NATNUM (column);
952 goal = XINT (column);
954 pos = PT;
955 pos_byte = PT_BYTE;
956 end = ZV;
958 /* If we're starting past the desired column,
959 back up to beginning of line and scan from there. */
960 if (col > goal)
962 end = pos;
963 pos = current_column_bol_cache;
964 pos_byte = CHAR_TO_BYTE (pos);
965 col = 0;
968 next_boundary = pos;
970 while (pos < end)
972 while (pos == next_boundary)
974 EMACS_INT prev = pos;
975 pos = skip_invisible (pos, &next_boundary, end, Qnil);
976 if (pos != prev)
977 pos_byte = CHAR_TO_BYTE (pos);
978 if (pos >= end)
979 goto endloop;
982 /* Test reaching the goal column. We do this after skipping
983 invisible characters, so that we put point before the
984 character on which the cursor will appear. */
985 if (col >= goal)
986 break;
988 /* Check composition sequence. */
990 int len, len_byte, width;
992 if (check_composition (pos, pos_byte, Z, &len, &len_byte, &width))
994 pos += len;
995 pos_byte += len_byte;
996 col += width;
997 continue;
1001 c = FETCH_BYTE (pos_byte);
1003 /* See if there is a display table and it relates
1004 to this character. */
1006 if (dp != 0
1007 && ! (multibyte && BASE_LEADING_CODE_P (c))
1008 && VECTORP (DISP_CHAR_VECTOR (dp, c)))
1010 Lisp_Object charvec;
1011 EMACS_INT i, n;
1013 /* This character is displayed using a vector of glyphs.
1014 Update the position based on those glyphs. */
1016 charvec = DISP_CHAR_VECTOR (dp, c);
1017 n = ASIZE (charvec);
1019 for (i = 0; i < n; i++)
1021 /* This should be handled the same as
1022 next_element_from_display_vector does it. */
1023 Lisp_Object entry = AREF (charvec, i);
1025 if (GLYPH_CODE_P (entry)
1026 && GLYPH_CODE_CHAR_VALID_P (entry))
1027 c = GLYPH_CODE_CHAR (entry);
1028 else
1029 c = ' ';
1031 if (c == '\n')
1032 goto endloop;
1033 if (c == '\r' && EQ (current_buffer->selective_display, Qt))
1034 goto endloop;
1035 if (c == '\t')
1037 prev_col = col;
1038 col += tab_width;
1039 col = col / tab_width * tab_width;
1041 else
1042 ++col;
1045 else
1047 /* The display table doesn't affect this character;
1048 it displays as itself. */
1050 if (c == '\n')
1051 goto endloop;
1052 if (c == '\r' && EQ (current_buffer->selective_display, Qt))
1053 goto endloop;
1054 if (c == '\t')
1056 prev_col = col;
1057 col += tab_width;
1058 col = col / tab_width * tab_width;
1060 else if (ctl_arrow && (c < 040 || c == 0177))
1061 col += 2;
1062 else if (c < 040 || c == 0177)
1063 col += 4;
1064 else if (c < 0177)
1065 col++;
1066 else if (multibyte && BASE_LEADING_CODE_P (c))
1068 /* Start of multi-byte form. */
1069 unsigned char *ptr;
1070 int bytes, width, wide_column;
1072 ptr = BYTE_POS_ADDR (pos_byte);
1073 MULTIBYTE_BYTES_WIDTH (ptr, dp);
1074 pos_byte += bytes - 1;
1075 col += width;
1077 else
1078 col += 4;
1081 pos++;
1082 pos_byte++;
1084 endloop:
1086 SET_PT_BOTH (pos, pos_byte);
1088 /* If a tab char made us overshoot, change it to spaces
1089 and scan through it again. */
1090 if (!NILP (force) && col > goal && c == '\t' && prev_col < goal)
1092 EMACS_INT goal_pt, goal_pt_byte;
1094 /* Insert spaces in front of the tab to reach GOAL. Do this
1095 first so that a marker at the end of the tab gets
1096 adjusted. */
1097 SET_PT_BOTH (PT - 1, PT_BYTE - 1);
1098 Finsert_char (make_number (' '), make_number (goal - prev_col), Qt);
1100 /* Now delete the tab, and indent to COL. */
1101 del_range (PT, PT + 1);
1102 goal_pt = PT;
1103 goal_pt_byte = PT_BYTE;
1104 Findent_to (make_number (col), Qnil);
1105 SET_PT_BOTH (goal_pt, goal_pt_byte);
1107 /* Set the last_known... vars consistently. */
1108 col = goal;
1111 /* If line ends prematurely, add space to the end. */
1112 if (col < goal && EQ (force, Qt))
1113 Findent_to (make_number (col = goal), Qnil);
1115 last_known_column = col;
1116 last_known_column_point = PT;
1117 last_known_column_modified = MODIFF;
1119 XSETFASTINT (val, col);
1120 return val;
1123 /* compute_motion: compute buffer posn given screen posn and vice versa */
1125 struct position val_compute_motion;
1127 /* Scan the current buffer forward from offset FROM, pretending that
1128 this is at line FROMVPOS, column FROMHPOS, until reaching buffer
1129 offset TO or line TOVPOS, column TOHPOS (whichever comes first),
1130 and return the ending buffer position and screen location. If we
1131 can't hit the requested column exactly (because of a tab or other
1132 multi-column character), overshoot.
1134 DID_MOTION is 1 if FROMHPOS has already accounted for overlay strings
1135 at FROM. This is the case if FROMVPOS and FROMVPOS came from an
1136 earlier call to compute_motion. The other common case is that FROMHPOS
1137 is zero and FROM is a position that "belongs" at column zero, but might
1138 be shifted by overlay strings; in this case DID_MOTION should be 0.
1140 WIDTH is the number of columns available to display text;
1141 compute_motion uses this to handle continuation lines and such.
1142 If WIDTH is -1, use width of window's text area adjusted for
1143 continuation glyph when needed.
1145 HSCROLL is the number of columns not being displayed at the left
1146 margin; this is usually taken from a window's hscroll member.
1147 TAB_OFFSET is the number of columns of the first tab that aren't
1148 being displayed, perhaps because of a continuation line or
1149 something.
1151 compute_motion returns a pointer to a struct position. The bufpos
1152 member gives the buffer position at the end of the scan, and hpos
1153 and vpos give its cartesian location. prevhpos is the column at
1154 which the character before bufpos started, and contin is non-zero
1155 if we reached the current line by continuing the previous.
1157 Note that FROMHPOS and TOHPOS should be expressed in real screen
1158 columns, taking HSCROLL and the truncation glyph at the left margin
1159 into account. That is, beginning-of-line moves you to the hpos
1160 -HSCROLL + (HSCROLL > 0).
1162 For example, to find the buffer position of column COL of line LINE
1163 of a certain window, pass the window's starting location as FROM
1164 and the window's upper-left coordinates as FROMVPOS and FROMHPOS.
1165 Pass the buffer's ZV as TO, to limit the scan to the end of the
1166 visible section of the buffer, and pass LINE and COL as TOVPOS and
1167 TOHPOS.
1169 When displaying in window w, a typical formula for WIDTH is:
1171 window_width - 1
1172 - (has_vertical_scroll_bars
1173 ? WINDOW_CONFIG_SCROLL_BAR_COLS (window)
1174 : (window_width + window_left != frame_cols))
1176 where
1177 window_width is XFASTINT (w->total_cols),
1178 window_left is XFASTINT (w->left_col),
1179 has_vertical_scroll_bars is
1180 WINDOW_HAS_VERTICAL_SCROLL_BAR (window)
1181 and frame_cols = FRAME_COLS (XFRAME (window->frame))
1183 Or you can let window_box_text_cols do this all for you, and write:
1184 window_box_text_cols (w) - 1
1186 The `-1' accounts for the continuation-line backslashes; the rest
1187 accounts for window borders if the window is split horizontally, and
1188 the scroll bars if they are turned on. */
1190 struct position *
1191 compute_motion (from, fromvpos, fromhpos, did_motion, to, tovpos, tohpos, width, hscroll, tab_offset, win)
1192 EMACS_INT from, fromvpos, fromhpos, to, tovpos, tohpos;
1193 int did_motion;
1194 EMACS_INT width;
1195 EMACS_INT hscroll, tab_offset;
1196 struct window *win;
1198 register EMACS_INT hpos = fromhpos;
1199 register EMACS_INT vpos = fromvpos;
1201 register EMACS_INT pos;
1202 EMACS_INT pos_byte;
1203 register int c = 0;
1204 register EMACS_INT tab_width = XFASTINT (current_buffer->tab_width);
1205 register int ctl_arrow = !NILP (current_buffer->ctl_arrow);
1206 register struct Lisp_Char_Table *dp = window_display_table (win);
1207 int selective
1208 = (INTEGERP (current_buffer->selective_display)
1209 ? XINT (current_buffer->selective_display)
1210 : !NILP (current_buffer->selective_display) ? -1 : 0);
1211 int selective_rlen
1212 = (selective && dp && VECTORP (DISP_INVIS_VECTOR (dp))
1213 ? XVECTOR (DISP_INVIS_VECTOR (dp))->size : 0);
1214 /* The next location where the `invisible' property changes, or an
1215 overlay starts or ends. */
1216 EMACS_INT next_boundary = from;
1218 /* For computing runs of characters with similar widths.
1219 Invariant: width_run_width is zero, or all the characters
1220 from width_run_start to width_run_end have a fixed width of
1221 width_run_width. */
1222 EMACS_INT width_run_start = from;
1223 EMACS_INT width_run_end = from;
1224 EMACS_INT width_run_width = 0;
1225 Lisp_Object *width_table;
1226 Lisp_Object buffer;
1228 /* The next buffer pos where we should consult the width run cache. */
1229 EMACS_INT next_width_run = from;
1230 Lisp_Object window;
1232 int multibyte = !NILP (current_buffer->enable_multibyte_characters);
1233 /* If previous char scanned was a wide character,
1234 this is the column where it ended. Otherwise, this is 0. */
1235 EMACS_INT wide_column_end_hpos = 0;
1236 EMACS_INT prev_pos; /* Previous buffer position. */
1237 EMACS_INT prev_pos_byte; /* Previous buffer position. */
1238 EMACS_INT prev_hpos = 0;
1239 EMACS_INT prev_vpos = 0;
1240 EMACS_INT contin_hpos; /* HPOS of last column of continued line. */
1241 EMACS_INT prev_tab_offset; /* Previous tab offset. */
1242 EMACS_INT continuation_glyph_width;
1244 XSETBUFFER (buffer, current_buffer);
1245 XSETWINDOW (window, win);
1247 width_run_cache_on_off ();
1248 if (dp == buffer_display_table ())
1249 width_table = (VECTORP (current_buffer->width_table)
1250 ? XVECTOR (current_buffer->width_table)->contents
1251 : 0);
1252 else
1253 /* If the window has its own display table, we can't use the width
1254 run cache, because that's based on the buffer's display table. */
1255 width_table = 0;
1257 if (tab_width <= 0 || tab_width > 1000)
1258 tab_width = 8;
1260 /* Negative width means use all available text columns. */
1261 if (width < 0)
1263 width = window_box_text_cols (win);
1264 /* We must make room for continuation marks if we don't have fringes. */
1265 #ifdef HAVE_WINDOW_SYSTEM
1266 if (!FRAME_WINDOW_P (XFRAME (win->frame)))
1267 #endif
1268 width -= 1;
1271 continuation_glyph_width = 1;
1272 #ifdef HAVE_WINDOW_SYSTEM
1273 if (FRAME_WINDOW_P (XFRAME (win->frame)))
1274 continuation_glyph_width = 0; /* In the fringe. */
1275 #endif
1277 immediate_quit = 1;
1278 QUIT;
1280 pos = prev_pos = from;
1281 pos_byte = prev_pos_byte = CHAR_TO_BYTE (from);
1282 contin_hpos = 0;
1283 prev_tab_offset = tab_offset;
1284 while (1)
1286 while (pos == next_boundary)
1288 EMACS_INT pos_here = pos;
1289 EMACS_INT newpos;
1291 /* Don't skip invisible if we are already at the margin. */
1292 if (vpos > tovpos || (vpos == tovpos && hpos >= tohpos))
1294 if (contin_hpos && prev_hpos == 0
1295 && hpos > tohpos
1296 && (contin_hpos == width || wide_column_end_hpos > width))
1297 { /* Line breaks because we can't put the character at the
1298 previous line any more. It is not the multi-column
1299 character continued in middle. Go back to previous
1300 buffer position, screen position, and set tab offset
1301 to previous value. It's the beginning of the
1302 line. */
1303 pos = prev_pos;
1304 pos_byte = prev_pos_byte;
1305 hpos = prev_hpos;
1306 vpos = prev_vpos;
1307 tab_offset = prev_tab_offset;
1309 break;
1312 /* If the caller says that the screen position came from an earlier
1313 call to compute_motion, then we've already accounted for the
1314 overlay strings at point. This is only true the first time
1315 through, so clear the flag after testing it. */
1316 if (!did_motion)
1317 /* We need to skip past the overlay strings. Currently those
1318 strings must not contain TAB;
1319 if we want to relax that restriction, something will have
1320 to be changed here. */
1322 unsigned char *ovstr;
1323 int ovlen = overlay_strings (pos, win, &ovstr);
1324 hpos += ((multibyte && ovlen > 0)
1325 ? strwidth (ovstr, ovlen) : ovlen);
1327 did_motion = 0;
1329 if (pos >= to)
1330 break;
1332 /* Advance POS past invisible characters
1333 (but not necessarily all that there are here),
1334 and store in next_boundary the next position where
1335 we need to call skip_invisible. */
1336 newpos = skip_invisible (pos, &next_boundary, to, window);
1338 if (newpos >= to)
1340 pos = min (to, newpos);
1341 pos_byte = CHAR_TO_BYTE (pos);
1342 goto after_loop;
1345 if (newpos != pos_here)
1347 pos = newpos;
1348 pos_byte = CHAR_TO_BYTE (pos);
1352 /* Handle right margin. */
1353 /* Note on a wide-column character.
1355 Characters are classified into the following three categories
1356 according to the width (columns occupied on screen).
1358 (1) single-column character: ex. `a'
1359 (2) multi-column character: ex. `^A', TAB, `\033'
1360 (3) wide-column character: ex. Japanese character, Chinese character
1361 (In the following example, `W_' stands for them.)
1363 Multi-column characters can be divided around the right margin,
1364 but wide-column characters cannot.
1366 NOTE:
1368 (*) The cursor is placed on the next character after the point.
1370 ----------
1371 abcdefghi\
1372 j ^---- next after the point
1373 ^--- next char. after the point.
1374 ----------
1375 In case of sigle-column character
1377 ----------
1378 abcdefgh\\
1379 033 ^---- next after the point, next char. after the point.
1380 ----------
1381 In case of multi-column character
1383 ----------
1384 abcdefgh\\
1385 W_ ^---- next after the point
1386 ^---- next char. after the point.
1387 ----------
1388 In case of wide-column character
1390 The problem here is continuation at a wide-column character.
1391 In this case, the line may shorter less than WIDTH.
1392 And we find the continuation AFTER it occurs.
1396 if (hpos > width)
1398 if (hscroll
1399 || (truncate_partial_width_windows
1400 && ((width + continuation_glyph_width)
1401 < FRAME_COLS (XFRAME (WINDOW_FRAME (win)))))
1402 || !NILP (current_buffer->truncate_lines))
1404 /* Truncating: skip to newline, unless we are already past
1405 TO (we need to go back below). */
1406 if (pos <= to)
1408 pos = find_before_next_newline (pos, to, 1);
1409 pos_byte = CHAR_TO_BYTE (pos);
1410 hpos = width;
1411 /* If we just skipped next_boundary,
1412 loop around in the main while
1413 and handle it. */
1414 if (pos >= next_boundary)
1415 next_boundary = pos + 1;
1416 prev_hpos = width;
1417 prev_vpos = vpos;
1418 prev_tab_offset = tab_offset;
1421 else
1423 /* Continuing. */
1424 /* Remember the previous value. */
1425 prev_tab_offset = tab_offset;
1427 if (wide_column_end_hpos > width)
1429 hpos -= prev_hpos;
1430 tab_offset += prev_hpos;
1432 else
1434 tab_offset += width;
1435 hpos -= width;
1437 vpos++;
1438 contin_hpos = prev_hpos;
1439 prev_hpos = 0;
1440 prev_vpos = vpos;
1444 /* Stop if past the target buffer position or screen position. */
1445 if (pos > to)
1447 /* Go back to the previous position. */
1448 pos = prev_pos;
1449 pos_byte = prev_pos_byte;
1450 hpos = prev_hpos;
1451 vpos = prev_vpos;
1452 tab_offset = prev_tab_offset;
1454 /* NOTE on contin_hpos, hpos, and prev_hpos.
1456 ----------
1457 abcdefgh\\
1458 W_ ^---- contin_hpos
1459 | ^----- hpos
1460 \---- prev_hpos
1461 ----------
1464 if (contin_hpos && prev_hpos == 0
1465 && contin_hpos < width && !wide_column_end_hpos)
1467 /* Line breaking occurs in the middle of multi-column
1468 character. Go back to previous line. */
1469 hpos = contin_hpos;
1470 vpos = vpos - 1;
1472 break;
1475 if (vpos > tovpos || (vpos == tovpos && hpos >= tohpos))
1477 if (contin_hpos && prev_hpos == 0
1478 && hpos > tohpos
1479 && (contin_hpos == width || wide_column_end_hpos > width))
1480 { /* Line breaks because we can't put the character at the
1481 previous line any more. It is not the multi-column
1482 character continued in middle. Go back to previous
1483 buffer position, screen position, and set tab offset
1484 to previous value. It's the beginning of the
1485 line. */
1486 pos = prev_pos;
1487 pos_byte = prev_pos_byte;
1488 hpos = prev_hpos;
1489 vpos = prev_vpos;
1490 tab_offset = prev_tab_offset;
1492 break;
1494 if (pos == ZV) /* We cannot go beyond ZV. Stop here. */
1495 break;
1497 prev_hpos = hpos;
1498 prev_vpos = vpos;
1499 prev_pos = pos;
1500 prev_pos_byte = pos_byte;
1501 wide_column_end_hpos = 0;
1503 /* Consult the width run cache to see if we can avoid inspecting
1504 the text character-by-character. */
1505 if (current_buffer->width_run_cache && pos >= next_width_run)
1507 int run_end;
1508 int common_width
1509 = region_cache_forward (current_buffer,
1510 current_buffer->width_run_cache,
1511 pos, &run_end);
1513 /* A width of zero means the character's width varies (like
1514 a tab), is meaningless (like a newline), or we just don't
1515 want to skip over it for some other reason. */
1516 if (common_width != 0)
1518 int run_end_hpos;
1520 /* Don't go past the final buffer posn the user
1521 requested. */
1522 if (run_end > to)
1523 run_end = to;
1525 run_end_hpos = hpos + (run_end - pos) * common_width;
1527 /* Don't go past the final horizontal position the user
1528 requested. */
1529 if (vpos == tovpos && run_end_hpos > tohpos)
1531 run_end = pos + (tohpos - hpos) / common_width;
1532 run_end_hpos = hpos + (run_end - pos) * common_width;
1535 /* Don't go past the margin. */
1536 if (run_end_hpos >= width)
1538 run_end = pos + (width - hpos) / common_width;
1539 run_end_hpos = hpos + (run_end - pos) * common_width;
1542 hpos = run_end_hpos;
1543 if (run_end > pos)
1544 prev_hpos = hpos - common_width;
1545 if (pos != run_end)
1547 pos = run_end;
1548 pos_byte = CHAR_TO_BYTE (pos);
1552 next_width_run = run_end + 1;
1555 /* We have to scan the text character-by-character. */
1556 else
1558 EMACS_INT i, n;
1559 Lisp_Object charvec;
1561 c = FETCH_BYTE (pos_byte);
1563 /* Check composition sequence. */
1565 int len, len_byte, width;
1567 if (check_composition (pos, pos_byte, to, &len, &len_byte, &width))
1569 pos += len;
1570 pos_byte += len_byte;
1571 hpos += width;
1572 continue;
1576 pos++, pos_byte++;
1578 /* Perhaps add some info to the width_run_cache. */
1579 if (current_buffer->width_run_cache)
1581 /* Is this character part of the current run? If so, extend
1582 the run. */
1583 if (pos - 1 == width_run_end
1584 && XFASTINT (width_table[c]) == width_run_width)
1585 width_run_end = pos;
1587 /* The previous run is over, since this is a character at a
1588 different position, or a different width. */
1589 else
1591 /* Have we accumulated a run to put in the cache?
1592 (Currently, we only cache runs of width == 1). */
1593 if (width_run_start < width_run_end
1594 && width_run_width == 1)
1595 know_region_cache (current_buffer,
1596 current_buffer->width_run_cache,
1597 width_run_start, width_run_end);
1599 /* Start recording a new width run. */
1600 width_run_width = XFASTINT (width_table[c]);
1601 width_run_start = pos - 1;
1602 width_run_end = pos;
1606 if (dp != 0
1607 && ! (multibyte && BASE_LEADING_CODE_P (c))
1608 && VECTORP (DISP_CHAR_VECTOR (dp, c)))
1610 charvec = DISP_CHAR_VECTOR (dp, c);
1611 n = ASIZE (charvec);
1613 else
1615 charvec = Qnil;
1616 n = 1;
1619 for (i = n - 1; i >= 0; --i)
1621 if (VECTORP (charvec))
1623 /* This should be handled the same as
1624 next_element_from_display_vector does it. */
1625 Lisp_Object entry = AREF (charvec, i);
1627 if (GLYPH_CODE_P (entry)
1628 && GLYPH_CODE_CHAR_VALID_P (entry))
1629 c = GLYPH_CODE_CHAR (entry);
1630 else
1631 c = ' ';
1634 if (c >= 040 && c < 0177)
1635 hpos++;
1636 else if (c == '\t')
1638 int tem = ((hpos + tab_offset + hscroll - (hscroll > 0))
1639 % tab_width);
1640 if (tem < 0)
1641 tem += tab_width;
1642 hpos += tab_width - tem;
1644 else if (c == '\n')
1646 if (selective > 0
1647 && indented_beyond_p (pos, pos_byte,
1648 (double) selective)) /* iftc */
1650 /* If (pos == to), we don't have to take care of
1651 selective display. */
1652 if (pos < to)
1654 /* Skip any number of invisible lines all at once */
1657 pos = find_before_next_newline (pos, to, 1);
1658 if (pos < to)
1659 pos++;
1660 pos_byte = CHAR_TO_BYTE (pos);
1662 while (pos < to
1663 && indented_beyond_p (pos, pos_byte,
1664 (double) selective)); /* iftc */
1665 /* Allow for the " ..." that is displayed for them. */
1666 if (selective_rlen)
1668 hpos += selective_rlen;
1669 if (hpos >= width)
1670 hpos = width;
1672 DEC_BOTH (pos, pos_byte);
1673 /* We have skipped the invis text, but not the
1674 newline after. */
1677 else
1679 /* A visible line. */
1680 vpos++;
1681 hpos = 0;
1682 hpos -= hscroll;
1683 /* Count the truncation glyph on column 0 */
1684 if (hscroll > 0)
1685 hpos += continuation_glyph_width;
1686 tab_offset = 0;
1688 contin_hpos = 0;
1690 else if (c == CR && selective < 0)
1692 /* In selective display mode,
1693 everything from a ^M to the end of the line is invisible.
1694 Stop *before* the real newline. */
1695 if (pos < to)
1697 pos = find_before_next_newline (pos, to, 1);
1698 pos_byte = CHAR_TO_BYTE (pos);
1700 /* If we just skipped next_boundary,
1701 loop around in the main while
1702 and handle it. */
1703 if (pos > next_boundary)
1704 next_boundary = pos;
1705 /* Allow for the " ..." that is displayed for them. */
1706 if (selective_rlen)
1708 hpos += selective_rlen;
1709 if (hpos >= width)
1710 hpos = width;
1713 else if (multibyte && BASE_LEADING_CODE_P (c))
1715 /* Start of multi-byte form. */
1716 unsigned char *ptr;
1717 int bytes, width, wide_column;
1719 pos_byte--; /* rewind POS_BYTE */
1720 ptr = BYTE_POS_ADDR (pos_byte);
1721 MULTIBYTE_BYTES_WIDTH (ptr, dp);
1722 pos_byte += bytes;
1723 if (wide_column)
1724 wide_column_end_hpos = hpos + wide_column;
1725 hpos += width;
1727 else if (VECTORP (charvec))
1728 ++hpos;
1729 else
1730 hpos += (ctl_arrow && c < 0200) ? 2 : 4;
1735 after_loop:
1737 /* Remember any final width run in the cache. */
1738 if (current_buffer->width_run_cache
1739 && width_run_width == 1
1740 && width_run_start < width_run_end)
1741 know_region_cache (current_buffer, current_buffer->width_run_cache,
1742 width_run_start, width_run_end);
1744 val_compute_motion.bufpos = pos;
1745 val_compute_motion.bytepos = pos_byte;
1746 val_compute_motion.hpos = hpos;
1747 val_compute_motion.vpos = vpos;
1748 if (contin_hpos && prev_hpos == 0)
1749 val_compute_motion.prevhpos = contin_hpos;
1750 else
1751 val_compute_motion.prevhpos = prev_hpos;
1752 /* We alalways handle all of them here; none of them remain to do. */
1753 val_compute_motion.ovstring_chars_done = 0;
1755 /* Nonzero if have just continued a line */
1756 val_compute_motion.contin = (contin_hpos && prev_hpos == 0);
1758 immediate_quit = 0;
1759 return &val_compute_motion;
1763 DEFUN ("compute-motion", Fcompute_motion, Scompute_motion, 7, 7, 0,
1764 doc: /* Scan through the current buffer, calculating screen position.
1765 Scan the current buffer forward from offset FROM,
1766 assuming it is at position FROMPOS--a cons of the form (HPOS . VPOS)--
1767 to position TO or position TOPOS--another cons of the form (HPOS . VPOS)--
1768 and return the ending buffer position and screen location.
1770 If TOPOS is nil, the actual width and height of the window's
1771 text area are used.
1773 There are three additional arguments:
1775 WIDTH is the number of columns available to display text;
1776 this affects handling of continuation lines. A value of nil
1777 corresponds to the actual number of available text columns.
1779 OFFSETS is either nil or a cons cell (HSCROLL . TAB-OFFSET).
1780 HSCROLL is the number of columns not being displayed at the left
1781 margin; this is usually taken from a window's hscroll member.
1782 TAB-OFFSET is the number of columns of the first tab that aren't
1783 being displayed, perhaps because the line was continued within it.
1784 If OFFSETS is nil, HSCROLL and TAB-OFFSET are assumed to be zero.
1786 WINDOW is the window to operate on. It is used to choose the display table;
1787 if it is showing the current buffer, it is used also for
1788 deciding which overlay properties apply.
1789 Note that `compute-motion' always operates on the current buffer.
1791 The value is a list of five elements:
1792 (POS HPOS VPOS PREVHPOS CONTIN)
1793 POS is the buffer position where the scan stopped.
1794 VPOS is the vertical position where the scan stopped.
1795 HPOS is the horizontal position where the scan stopped.
1797 PREVHPOS is the horizontal position one character back from POS.
1798 CONTIN is t if a line was continued after (or within) the previous character.
1800 For example, to find the buffer position of column COL of line LINE
1801 of a certain window, pass the window's starting location as FROM
1802 and the window's upper-left coordinates as FROMPOS.
1803 Pass the buffer's (point-max) as TO, to limit the scan to the end of the
1804 visible section of the buffer, and pass LINE and COL as TOPOS. */)
1805 (from, frompos, to, topos, width, offsets, window)
1806 Lisp_Object from, frompos, to, topos;
1807 Lisp_Object width, offsets, window;
1809 struct window *w;
1810 Lisp_Object bufpos, hpos, vpos, prevhpos;
1811 struct position *pos;
1812 int hscroll, tab_offset;
1814 CHECK_NUMBER_COERCE_MARKER (from);
1815 CHECK_CONS (frompos);
1816 CHECK_NUMBER_CAR (frompos);
1817 CHECK_NUMBER_CDR (frompos);
1818 CHECK_NUMBER_COERCE_MARKER (to);
1819 if (!NILP (topos))
1821 CHECK_CONS (topos);
1822 CHECK_NUMBER_CAR (topos);
1823 CHECK_NUMBER_CDR (topos);
1825 if (!NILP (width))
1826 CHECK_NUMBER (width);
1828 if (!NILP (offsets))
1830 CHECK_CONS (offsets);
1831 CHECK_NUMBER_CAR (offsets);
1832 CHECK_NUMBER_CDR (offsets);
1833 hscroll = XINT (XCAR (offsets));
1834 tab_offset = XINT (XCDR (offsets));
1836 else
1837 hscroll = tab_offset = 0;
1839 if (NILP (window))
1840 window = Fselected_window ();
1841 else
1842 CHECK_LIVE_WINDOW (window);
1843 w = XWINDOW (window);
1845 if (XINT (from) < BEGV || XINT (from) > ZV)
1846 args_out_of_range_3 (from, make_number (BEGV), make_number (ZV));
1847 if (XINT (to) < BEGV || XINT (to) > ZV)
1848 args_out_of_range_3 (to, make_number (BEGV), make_number (ZV));
1850 pos = compute_motion (XINT (from), XINT (XCDR (frompos)),
1851 XINT (XCAR (frompos)), 0,
1852 XINT (to),
1853 (NILP (topos)
1854 ? window_internal_height (w)
1855 : XINT (XCDR (topos))),
1856 (NILP (topos)
1857 ? (window_box_text_cols (w)
1859 #ifdef HAVE_WINDOW_SYSTEM
1860 FRAME_WINDOW_P (XFRAME (w->frame)) ? 0 :
1861 #endif
1863 : XINT (XCAR (topos))),
1864 (NILP (width) ? -1 : XINT (width)),
1865 hscroll, tab_offset,
1866 XWINDOW (window));
1868 XSETFASTINT (bufpos, pos->bufpos);
1869 XSETINT (hpos, pos->hpos);
1870 XSETINT (vpos, pos->vpos);
1871 XSETINT (prevhpos, pos->prevhpos);
1873 return Fcons (bufpos,
1874 Fcons (hpos,
1875 Fcons (vpos,
1876 Fcons (prevhpos,
1877 Fcons (pos->contin ? Qt : Qnil, Qnil)))));
1881 /* Fvertical_motion and vmotion */
1883 struct position val_vmotion;
1885 struct position *
1886 vmotion (from, vtarget, w)
1887 register EMACS_INT from, vtarget;
1888 struct window *w;
1890 EMACS_INT hscroll = XINT (w->hscroll);
1891 struct position pos;
1892 /* vpos is cumulative vertical position, changed as from is changed */
1893 register int vpos = 0;
1894 EMACS_INT prevline;
1895 register EMACS_INT first;
1896 EMACS_INT from_byte;
1897 EMACS_INT lmargin = hscroll > 0 ? 1 - hscroll : 0;
1898 int selective
1899 = (INTEGERP (current_buffer->selective_display)
1900 ? XINT (current_buffer->selective_display)
1901 : !NILP (current_buffer->selective_display) ? -1 : 0);
1902 Lisp_Object window;
1903 EMACS_INT start_hpos = 0;
1904 int did_motion;
1905 /* This is the object we use for fetching character properties. */
1906 Lisp_Object text_prop_object;
1908 XSETWINDOW (window, w);
1910 /* If the window contains this buffer, use it for getting text properties.
1911 Otherwise use the current buffer as arg for doing that. */
1912 if (EQ (w->buffer, Fcurrent_buffer ()))
1913 text_prop_object = window;
1914 else
1915 text_prop_object = Fcurrent_buffer ();
1917 if (vpos >= vtarget)
1919 /* To move upward, go a line at a time until
1920 we have gone at least far enough. */
1922 first = 1;
1924 while ((vpos > vtarget || first) && from > BEGV)
1926 Lisp_Object propval;
1928 prevline = find_next_newline_no_quit (from - 1, -1);
1929 while (prevline > BEGV
1930 && ((selective > 0
1931 && indented_beyond_p (prevline,
1932 CHAR_TO_BYTE (prevline),
1933 (double) selective)) /* iftc */
1934 /* Watch out for newlines with `invisible' property.
1935 When moving upward, check the newline before. */
1936 || (propval = Fget_char_property (make_number (prevline - 1),
1937 Qinvisible,
1938 text_prop_object),
1939 TEXT_PROP_MEANS_INVISIBLE (propval))))
1940 prevline = find_next_newline_no_quit (prevline - 1, -1);
1941 pos = *compute_motion (prevline, 0,
1942 lmargin + (prevline == BEG ? start_hpos : 0),
1944 from,
1945 /* Don't care for VPOS... */
1946 1 << (BITS_PER_SHORT - 1),
1947 /* ... nor HPOS. */
1948 1 << (BITS_PER_SHORT - 1),
1949 -1, hscroll,
1950 /* This compensates for start_hpos
1951 so that a tab as first character
1952 still occupies 8 columns. */
1953 (prevline == BEG ? -start_hpos : 0),
1955 vpos -= pos.vpos;
1956 first = 0;
1957 from = prevline;
1960 /* If we made exactly the desired vertical distance,
1961 or if we hit beginning of buffer,
1962 return point found */
1963 if (vpos >= vtarget)
1965 val_vmotion.bufpos = from;
1966 val_vmotion.bytepos = CHAR_TO_BYTE (from);
1967 val_vmotion.vpos = vpos;
1968 val_vmotion.hpos = lmargin;
1969 val_vmotion.contin = 0;
1970 val_vmotion.prevhpos = 0;
1971 val_vmotion.ovstring_chars_done = 0;
1972 val_vmotion.tab_offset = 0; /* For accumulating tab offset. */
1973 return &val_vmotion;
1976 /* Otherwise find the correct spot by moving down */
1978 /* Moving downward is simple, but must calculate from beg of line
1979 to determine hpos of starting point */
1980 from_byte = CHAR_TO_BYTE (from);
1981 if (from > BEGV && FETCH_BYTE (from_byte - 1) != '\n')
1983 Lisp_Object propval;
1985 prevline = find_next_newline_no_quit (from, -1);
1986 while (prevline > BEGV
1987 && ((selective > 0
1988 && indented_beyond_p (prevline,
1989 CHAR_TO_BYTE (prevline),
1990 (double) selective)) /* iftc */
1991 /* Watch out for newlines with `invisible' property.
1992 When moving downward, check the newline after. */
1993 || (propval = Fget_char_property (make_number (prevline),
1994 Qinvisible,
1995 text_prop_object),
1996 TEXT_PROP_MEANS_INVISIBLE (propval))))
1997 prevline = find_next_newline_no_quit (prevline - 1, -1);
1998 pos = *compute_motion (prevline, 0,
1999 lmargin + (prevline == BEG
2000 ? start_hpos : 0),
2002 from,
2003 /* Don't care for VPOS... */
2004 1 << (BITS_PER_SHORT - 1),
2005 /* ... nor HPOS. */
2006 1 << (BITS_PER_SHORT - 1),
2007 -1, hscroll,
2008 (prevline == BEG ? -start_hpos : 0),
2010 did_motion = 1;
2012 else
2014 pos.hpos = lmargin + (from == BEG ? start_hpos : 0);
2015 pos.vpos = 0;
2016 pos.tab_offset = 0;
2017 did_motion = 0;
2019 return compute_motion (from, vpos, pos.hpos, did_motion,
2020 ZV, vtarget, - (1 << (BITS_PER_SHORT - 1)),
2021 -1, hscroll,
2022 pos.tab_offset - (from == BEG ? start_hpos : 0),
2026 DEFUN ("vertical-motion", Fvertical_motion, Svertical_motion, 1, 2, 0,
2027 doc: /* Move point to start of the screen line LINES lines down.
2028 If LINES is negative, this means moving up.
2030 This function is an ordinary cursor motion function
2031 which calculates the new position based on how text would be displayed.
2032 The new position may be the start of a line,
2033 or just the start of a continuation line.
2034 The function returns number of screen lines moved over;
2035 that usually equals LINES, but may be closer to zero
2036 if beginning or end of buffer was reached.
2038 The optional second argument WINDOW specifies the window to use for
2039 parameters such as width, horizontal scrolling, and so on.
2040 The default is to use the selected window's parameters.
2042 `vertical-motion' always uses the current buffer,
2043 regardless of which buffer is displayed in WINDOW.
2044 This is consistent with other cursor motion functions
2045 and makes it possible to use `vertical-motion' in any buffer,
2046 whether or not it is currently displayed in some window. */)
2047 (lines, window)
2048 Lisp_Object lines, window;
2050 struct it it;
2051 struct text_pos pt;
2052 struct window *w;
2053 Lisp_Object old_buffer;
2054 struct gcpro gcpro1;
2056 CHECK_NUMBER (lines);
2057 if (! NILP (window))
2058 CHECK_WINDOW (window);
2059 else
2060 window = selected_window;
2061 w = XWINDOW (window);
2063 old_buffer = Qnil;
2064 GCPRO1 (old_buffer);
2065 if (XBUFFER (w->buffer) != current_buffer)
2067 /* Set the window's buffer temporarily to the current buffer. */
2068 old_buffer = w->buffer;
2069 XSETBUFFER (w->buffer, current_buffer);
2072 if (noninteractive)
2074 struct position pos;
2075 pos = *vmotion (PT, XINT (lines), w);
2076 SET_PT_BOTH (pos.bufpos, pos.bytepos);
2078 else
2080 int it_start;
2081 int oselective;
2082 int it_overshoot_expected;
2084 SET_TEXT_POS (pt, PT, PT_BYTE);
2085 start_display (&it, w, pt);
2087 /* Scan from the start of the line containing PT. If we don't
2088 do this, we start moving with IT->current_x == 0, while PT is
2089 really at some x > 0. The effect is, in continuation lines, that
2090 we end up with the iterator placed at where it thinks X is 0,
2091 while the end position is really at some X > 0, the same X that
2092 PT had. */
2093 it_start = IT_CHARPOS (it);
2095 /* We expect the call to move_it_to, further down, to overshoot
2096 if the starting point is on an image, stretch glyph,
2097 composition, or Lisp string. We won't need to backtrack in
2098 this situation, except for one corner case: when the Lisp
2099 string contains a newline. */
2100 if (it.method == GET_FROM_STRING)
2102 const char *s = SDATA (it.string);
2103 const char *e = s + SBYTES (it.string);
2105 while (s < e && *s != '\n')
2106 ++s;
2108 /* If there is no newline in the string, we need to check
2109 whether there is a newline immediately after the string
2110 in move_it_to below. This may happen if there is an
2111 overlay with an after-string just before the newline. */
2112 it_overshoot_expected = (s == e) ? -1 : 0;
2114 else
2115 it_overshoot_expected = (it.method == GET_FROM_IMAGE
2116 || it.method == GET_FROM_STRETCH
2117 || it.method == GET_FROM_COMPOSITION);
2119 reseat_at_previous_visible_line_start (&it);
2120 it.current_x = it.hpos = 0;
2121 /* Temporarily disable selective display so we don't move too far */
2122 oselective = it.selective;
2123 it.selective = 0;
2124 move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
2125 it.selective = oselective;
2127 /* Move back if we got too far. This may happen if
2128 truncate-lines is on and PT is beyond right margin.
2129 Don't go back if the overshoot is expected (see above). */
2130 if (IT_CHARPOS (it) > it_start && XINT (lines) > 0
2131 && (!it_overshoot_expected
2132 || (it_overshoot_expected < 0
2133 && it.method == GET_FROM_BUFFER
2134 && it.c == '\n')))
2135 move_it_by_lines (&it, -1, 0);
2137 it.vpos = 0;
2138 /* Do this even if LINES is 0, so that we move back
2139 to the beginning of the current line as we ought. */
2140 if (XINT (lines) >= 0 || IT_CHARPOS (it) > 0)
2141 move_it_by_lines (&it, XINT (lines), 0);
2143 SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
2146 if (BUFFERP (old_buffer))
2147 w->buffer = old_buffer;
2149 RETURN_UNGCPRO (make_number (it.vpos));
2154 /* File's initialization. */
2156 void
2157 syms_of_indent ()
2159 DEFVAR_BOOL ("indent-tabs-mode", &indent_tabs_mode,
2160 doc: /* *Indentation can insert tabs if this is non-nil. */);
2161 indent_tabs_mode = 1;
2163 defsubr (&Scurrent_indentation);
2164 defsubr (&Sindent_to);
2165 defsubr (&Scurrent_column);
2166 defsubr (&Smove_to_column);
2167 defsubr (&Svertical_motion);
2168 defsubr (&Scompute_motion);
2171 /* arch-tag: 9adfea44-71f7-4988-8ee3-96da15c502cc
2172 (do not change this comment) */