1 /* Indentation functions.
2 Copyright (C) 1985,86,87,88,93,94,95,98 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs; see the file COPYING. If not, write to
18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
33 #include "intervals.h"
34 #include "region-cache.h"
36 /* Indentation can insert tabs if this is non-zero;
37 otherwise always uses spaces */
40 #define min(a, b) ((a) < (b) ? (a) : (b))
41 #define max(a, b) ((a) > (b) ? (a) : (b))
45 /* These three values memoize the current column to avoid recalculation */
46 /* Some things in set last_known_column_point to -1
47 to mark the memoized value as invalid */
48 /* Last value returned by current_column */
49 int last_known_column
;
50 /* Value of point when current_column was called */
51 int last_known_column_point
;
52 /* Value of MODIFF when current_column was called */
53 int last_known_column_modified
;
55 static int current_column_1 ();
56 static int position_indentation ();
58 /* Cache of beginning of line found by the last call of
60 int current_column_bol_cache
;
62 /* Get the display table to use for the current buffer. */
64 struct Lisp_Char_Table
*
65 buffer_display_table ()
69 thisbuf
= current_buffer
->display_table
;
70 if (DISP_TABLE_P (thisbuf
))
71 return XCHAR_TABLE (thisbuf
);
72 if (DISP_TABLE_P (Vstandard_display_table
))
73 return XCHAR_TABLE (Vstandard_display_table
);
77 /* Width run cache considerations. */
79 /* Return the width of character C under display table DP. */
82 character_width (c
, dp
)
84 struct Lisp_Char_Table
*dp
;
88 /* These width computations were determined by examining the cases
89 in display_text_line. */
91 /* Everything can be handled by the display table, if it's
92 present and the element is right. */
93 if (dp
&& (elt
= DISP_CHAR_VECTOR (dp
, c
), VECTORP (elt
)))
94 return XVECTOR (elt
)->size
;
96 /* Some characters are special. */
97 if (c
== '\n' || c
== '\t' || c
== '\015')
100 /* Printing characters have width 1. */
101 else if (c
>= 040 && c
< 0177)
104 /* Everybody else (control characters, metacharacters) has other
105 widths. We could return their actual widths here, but they
106 depend on things like ctl_arrow and crud like that, and they're
107 not very common at all. So we'll just claim we don't know their
113 /* Return true iff the display table DISPTAB specifies the same widths
114 for characters as WIDTHTAB. We use this to decide when to
115 invalidate the buffer's width_run_cache. */
117 disptab_matches_widthtab (disptab
, widthtab
)
118 struct Lisp_Char_Table
*disptab
;
119 struct Lisp_Vector
*widthtab
;
123 if (widthtab
->size
!= 256)
126 for (i
= 0; i
< 256; i
++)
127 if (character_width (i
, disptab
)
128 != XFASTINT (widthtab
->contents
[i
]))
134 /* Recompute BUF's width table, using the display table DISPTAB. */
136 recompute_width_table (buf
, disptab
)
138 struct Lisp_Char_Table
*disptab
;
141 struct Lisp_Vector
*widthtab
;
143 if (!VECTORP (buf
->width_table
))
144 buf
->width_table
= Fmake_vector (make_number (256), make_number (0));
145 widthtab
= XVECTOR (buf
->width_table
);
146 if (widthtab
->size
!= 256)
149 for (i
= 0; i
< 256; i
++)
150 XSETFASTINT (widthtab
->contents
[i
], character_width (i
, disptab
));
153 /* Allocate or free the width run cache, as requested by the current
154 state of current_buffer's cache_long_line_scans variable. */
156 width_run_cache_on_off ()
158 if (NILP (current_buffer
->cache_long_line_scans
)
159 /* And, for the moment, this feature doesn't work on multibyte
161 || !NILP (current_buffer
->enable_multibyte_characters
))
163 /* It should be off. */
164 if (current_buffer
->width_run_cache
)
166 free_region_cache (current_buffer
->width_run_cache
);
167 current_buffer
->width_run_cache
= 0;
168 current_buffer
->width_table
= Qnil
;
173 /* It should be on. */
174 if (current_buffer
->width_run_cache
== 0)
176 current_buffer
->width_run_cache
= new_region_cache ();
177 recompute_width_table (current_buffer
, buffer_display_table ());
183 /* Skip some invisible characters starting from POS.
184 This includes characters invisible because of text properties
185 and characters invisible because of overlays.
187 If position POS is followed by invisible characters,
188 skip some of them and return the position after them.
189 Otherwise return POS itself.
191 Set *NEXT_BOUNDARY_P to the next position at which
192 it will be necessary to call this function again.
194 Don't scan past TO, and don't set *NEXT_BOUNDARY_P
195 to a value greater than TO.
197 If WINDOW is non-nil, and this buffer is displayed in WINDOW,
198 take account of overlays that apply only in WINDOW.
200 We don't necessarily skip all the invisible characters after POS
201 because that could take a long time. We skip a reasonable number
202 which can be skipped quickly. If there might be more invisible
203 characters immediately following, then *NEXT_BOUNDARY_P
204 will equal the return value. */
207 skip_invisible (pos
, next_boundary_p
, to
, window
)
209 int *next_boundary_p
;
213 Lisp_Object prop
, position
, overlay_limit
, proplimit
;
217 XSETFASTINT (position
, pos
);
218 XSETBUFFER (buffer
, current_buffer
);
220 /* Give faster response for overlay lookup near POS. */
221 recenter_overlay_lists (current_buffer
, pos
);
223 /* We must not advance farther than the next overlay change.
224 The overlay change might change the invisible property;
225 or there might be overlay strings to be displayed there. */
226 overlay_limit
= Fnext_overlay_change (position
);
227 /* As for text properties, this gives a lower bound
228 for where the invisible text property could change. */
229 proplimit
= Fnext_property_change (position
, buffer
, Qt
);
230 if (XFASTINT (overlay_limit
) < XFASTINT (proplimit
))
231 proplimit
= overlay_limit
;
232 /* PROPLIMIT is now a lower bound for the next change
233 in invisible status. If that is plenty far away,
234 use that lower bound. */
235 if (XFASTINT (proplimit
) > pos
+ 100 || XFASTINT (proplimit
) >= to
)
236 *next_boundary_p
= XFASTINT (proplimit
);
237 /* Otherwise, scan for the next `invisible' property change. */
240 /* Don't scan terribly far. */
241 XSETFASTINT (proplimit
, min (pos
+ 100, to
));
242 /* No matter what. don't go past next overlay change. */
243 if (XFASTINT (overlay_limit
) < XFASTINT (proplimit
))
244 proplimit
= overlay_limit
;
245 end
= XFASTINT (Fnext_single_property_change (position
, Qinvisible
,
248 /* Don't put the boundary in the middle of multibyte form if
249 there is no actual property change. */
251 && !NILP (current_buffer
->enable_multibyte_characters
)
253 while (pos
< end
&& !CHAR_HEAD_P (POS_ADDR (end
)))
256 *next_boundary_p
= end
;
258 /* if the `invisible' property is set, we can skip to
259 the next property change */
260 if (!NILP (window
) && EQ (XWINDOW (window
)->buffer
, buffer
))
261 prop
= Fget_char_property (position
, Qinvisible
, window
);
263 prop
= Fget_char_property (position
, Qinvisible
, buffer
);
264 if (TEXT_PROP_MEANS_INVISIBLE (prop
))
265 return *next_boundary_p
;
269 /* Set variables WIDTH and BYTES for a multibyte sequence starting at P.
271 C is *P which should satisfy `BASE_LEADING_CODE_P (c)'.
273 DP is a display table or NULL.
275 This macro is used in current_column_1, Fmove_to_column, and
278 #define MULTIBYTE_BYTES_WIDTH(p, c, dp) \
280 unsigned char *pend = p + 1; \
283 while (! CHAR_HEAD_P (*pend)) pend++; \
285 if (c == LEADING_CODE_COMPOSITION) \
287 int id = str_cmpchar_id (p, pend - p); \
288 int ch = MAKE_COMPOSITE_CHAR (id); \
292 bytes = cmpchar_table[id]->len; \
293 if (dp != 0 && VECTORP (DISP_CHAR_VECTOR (dp, ch))) \
294 width = XVECTOR (DISP_CHAR_VECTOR (dp, ch))->size; \
296 width = cmpchar_table[id]->width; \
298 wide_column = width; \
308 bytes = BYTES_BY_CHAR_HEAD (c); \
309 if (bytes >= 2 && bytes <= pend - p) \
311 int ch = STRING_CHAR (p, bytes); \
313 if (CHAR_VALID_P (ch, 0)) \
315 if (dp && VECTORP (DISP_CHAR_VECTOR (dp, ch))) \
316 width = XVECTOR (DISP_CHAR_VECTOR (dp, ch))->size; \
318 width = WIDTH_BY_CHAR_HEAD (c); \
323 wide_column = width; \
331 if (p + bytes < pend) \
333 width += 4 * (pend - (p + bytes)); \
338 DEFUN ("current-column", Fcurrent_column
, Scurrent_column
, 0, 0, 0,
339 "Return the horizontal position of point. Beginning of line is column 0.\n\
340 This is calculated by adding together the widths of all the displayed\n\
341 representations of the character between the start of the previous line\n\
342 and point. (eg control characters will have a width of 2 or 4, tabs\n\
343 will have a variable width)\n\
344 Ignores finite width of frame, which means that this function may return\n\
345 values greater than (frame-width).\n\
346 Whether the line is visible (if `selective-display' is t) has no effect;\n\
347 however, ^M is treated as end of line when `selective-display' is t.")
351 XSETFASTINT (temp
, current_column ());
355 /* Cancel any recorded value of the horizontal position. */
358 invalidate_current_column ()
360 last_known_column_point
= 0;
367 register unsigned char *ptr
, *stop
;
368 register int tab_seen
;
371 register int tab_width
= XINT (current_buffer
->tab_width
);
372 int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
373 register struct Lisp_Char_Table
*dp
= buffer_display_table ();
376 if (PT
== last_known_column_point
377 && MODIFF
== last_known_column_modified
)
378 return last_known_column
;
380 /* If the buffer has overlays, text properties,
381 or multibyte characters, use a more general algorithm. */
382 if (BUF_INTERVALS (current_buffer
)
383 || !NILP (current_buffer
->overlays_before
)
384 || !NILP (current_buffer
->overlays_after
)
386 return current_column_1 ();
388 /* Scan backwards from point to the previous newline,
389 counting width. Tab characters are the only complicated case. */
391 /* Make a pointer for decrementing through the chars before point. */
392 ptr
= BYTE_POS_ADDR (PT_BYTE
- 1) + 1;
393 /* Make a pointer to where consecutive chars leave off,
394 going backwards from point. */
397 else if (PT
<= GPT
|| BEGV
> GPT
)
402 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
404 col
= 0, tab_seen
= 0, post_tab
= 0;
410 /* We stopped either for the beginning of the buffer
412 if (ptr
== BEGV_ADDR
)
414 /* It was the gap. Jump back over it. */
417 /* Check whether that brings us to beginning of buffer. */
418 if (BEGV
>= GPT
) break;
422 if (dp
!= 0 && VECTORP (DISP_CHAR_VECTOR (dp
, c
)))
423 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
424 else if (c
>= 040 && c
< 0177)
427 || (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
)))
435 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
442 col
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
447 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
451 if (ptr
== BEGV_ADDR
)
452 current_column_bol_cache
= BEGV
;
454 current_column_bol_cache
= BYTE_TO_CHAR (PTR_BYTE_POS (ptr
));
456 last_known_column
= col
;
457 last_known_column_point
= PT
;
458 last_known_column_modified
= MODIFF
;
463 /* Return the column number of position POS
464 by scanning forward from the beginning of the line.
465 This function handles characters that are invisible
466 due to text properties or overlays. */
471 register int tab_width
= XINT (current_buffer
->tab_width
);
472 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
473 register struct Lisp_Char_Table
*dp
= buffer_display_table ();
474 int multibyte
= !NILP (current_buffer
->enable_multibyte_characters
);
476 /* Start the scan at the beginning of this line with column number 0. */
477 register int col
= 0;
479 int next_boundary
, next_boundary_byte
;
480 int opoint
= PT
, opoint_byte
= PT_BYTE
;
482 scan_newline (PT
, PT_BYTE
, BEGV
, BEGV_BYTE
, -1, 1);
483 current_column_bol_cache
= PT
;
484 scan
= PT
, scan_byte
= PT_BYTE
;
485 SET_PT_BOTH (opoint
, opoint_byte
);
486 next_boundary
= scan
;
487 next_boundary_byte
= scan_byte
;
489 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
491 /* Scan forward to the target position. */
492 while (scan
< opoint
)
496 /* Occasionally we may need to skip invisible text. */
497 while (scan
== next_boundary
)
500 /* This updates NEXT_BOUNDARY to the next place
501 where we might need to skip more invisible text. */
502 scan
= skip_invisible (scan
, &next_boundary
, opoint
, Qnil
);
505 if (scan
!= old_scan
)
506 scan_byte
= CHAR_TO_BYTE (scan
);
507 next_boundary_byte
= CHAR_TO_BYTE (next_boundary
);
510 c
= FETCH_BYTE (scan_byte
);
512 && ! (multibyte
&& BASE_LEADING_CODE_P (c
))
513 && VECTORP (DISP_CHAR_VECTOR (dp
, c
)))
515 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
522 if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
530 col
= col
/ tab_width
* tab_width
;
532 else if (multibyte
&& BASE_LEADING_CODE_P (c
))
535 int bytes
, width
, wide_column
;
538 ptr
= BYTE_POS_ADDR (scan_byte
);
539 MULTIBYTE_BYTES_WIDTH (ptr
, c
, dp
);
543 else if (ctl_arrow
&& (c
< 040 || c
== 0177))
545 else if (c
< 040 || c
>= 0177)
552 last_known_column
= col
;
553 last_known_column_point
= PT
;
554 last_known_column_modified
= MODIFF
;
559 /* Return the width in columns of the part of STRING from BEG to END.
560 If BEG is nil, that stands for the beginning of STRING.
561 If END is nil, that stands for the end of STRING. */
564 string_display_width (string
, beg
, end
)
565 Lisp_Object string
, beg
, end
;
568 register unsigned char *ptr
, *stop
;
569 register int tab_seen
;
572 register int tab_width
= XINT (current_buffer
->tab_width
);
573 int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
574 register struct Lisp_Char_Table
*dp
= buffer_display_table ();
578 e
= XSTRING (string
)->size
;
581 CHECK_NUMBER (end
, 0);
589 CHECK_NUMBER (beg
, 0);
593 /* Make a pointer for decrementing through the chars before point. */
594 ptr
= XSTRING (string
)->data
+ e
;
595 /* Make a pointer to where consecutive chars leave off,
596 going backwards from point. */
597 stop
= XSTRING (string
)->data
+ b
;
599 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
601 col
= 0, tab_seen
= 0, post_tab
= 0;
609 if (dp
!= 0 && VECTORP (DISP_CHAR_VECTOR (dp
, c
)))
610 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
611 else if (c
>= 040 && c
< 0177)
618 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
625 col
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
630 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
637 DEFUN ("indent-to", Findent_to
, Sindent_to
, 1, 2, "NIndent to column: ",
638 "Indent from point with tabs and spaces until COLUMN is reached.\n\
639 Optional second argument MININUM says always do at least MININUM spaces\n\
640 even if that goes past COLUMN; by default, MININUM is zero.")
642 Lisp_Object column
, minimum
;
645 register int fromcol
;
646 register int tab_width
= XINT (current_buffer
->tab_width
);
648 CHECK_NUMBER (column
, 0);
650 XSETFASTINT (minimum
, 0);
651 CHECK_NUMBER (minimum
, 1);
653 fromcol
= current_column ();
654 mincol
= fromcol
+ XINT (minimum
);
655 if (mincol
< XINT (column
)) mincol
= XINT (column
);
657 if (fromcol
== mincol
)
658 return make_number (mincol
);
660 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
662 if (indent_tabs_mode
)
665 XSETFASTINT (n
, mincol
/ tab_width
- fromcol
/ tab_width
);
666 if (XFASTINT (n
) != 0)
668 Finsert_char (make_number ('\t'), n
, Qt
);
670 fromcol
= (mincol
/ tab_width
) * tab_width
;
674 XSETFASTINT (column
, mincol
- fromcol
);
675 Finsert_char (make_number (' '), column
, Qt
);
677 last_known_column
= mincol
;
678 last_known_column_point
= PT
;
679 last_known_column_modified
= MODIFF
;
681 XSETINT (column
, mincol
);
686 static int position_indentation
P_ ((int));
688 DEFUN ("current-indentation", Fcurrent_indentation
, Scurrent_indentation
,
690 "Return the indentation of the current line.\n\
691 This is the horizontal position of the character\n\
692 following any initial whitespace.")
696 int opoint
= PT
, opoint_byte
= PT_BYTE
;
698 scan_newline (PT
, PT_BYTE
, BEGV
, BEGV_BYTE
, -1, 1);
700 XSETFASTINT (val
, position_indentation (PT_BYTE
));
701 SET_PT_BOTH (opoint
, opoint_byte
);
706 position_indentation (pos_byte
)
707 register int pos_byte
;
709 register int column
= 0;
710 register int tab_width
= XINT (current_buffer
->tab_width
);
711 register unsigned char *p
;
712 register unsigned char *stop
;
713 unsigned char *start
;
714 int next_boundary_byte
= pos_byte
;
715 int ceiling
= next_boundary_byte
;
717 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
719 p
= BYTE_POS_ADDR (pos_byte
);
720 /* STOP records the value of P at which we will need
721 to think about the gap, or about invisible text,
722 or about the end of the buffer. */
724 /* START records the starting value of P. */
732 /* If we have updated P, set POS_BYTE to match.
733 The first time we enter the loop, POS_BYTE is already right. */
735 pos_byte
= PTR_BYTE_POS (p
);
736 /* Consider the various reasons STOP might have been set here. */
737 if (pos_byte
== ZV_BYTE
)
739 if (pos_byte
== next_boundary_byte
)
742 int pos
= BYTE_TO_CHAR (pos_byte
);
743 pos
= skip_invisible (pos
, &next_boundary
, ZV
, Qnil
);
744 pos_byte
= CHAR_TO_BYTE (pos
);
745 next_boundary_byte
= CHAR_TO_BYTE (next_boundary
);
747 if (pos_byte
>= ceiling
)
748 ceiling
= BUFFER_CEILING_OF (pos_byte
) + 1;
749 /* Compute the next place we need to stop and think,
750 and set STOP accordingly. */
751 stop_pos_byte
= min (ceiling
, next_boundary_byte
);
752 /* The -1 and +1 arrange to point at the first byte of gap
753 (if STOP_POS_BYTE is the position of the gap)
754 rather than at the data after the gap. */
756 stop
= BYTE_POS_ADDR (stop_pos_byte
- 1) + 1;
757 p
= BYTE_POS_ADDR (pos_byte
);
762 if (! NILP (current_buffer
->enable_multibyte_characters
))
768 column
+= tab_width
- column
% tab_width
;
771 if (ASCII_BYTE_P (p
[-1])
772 || NILP (current_buffer
->enable_multibyte_characters
))
776 pos_byte
= PTR_BYTE_POS (p
- 1);
777 c
= FETCH_MULTIBYTE_CHAR (pos_byte
);
778 if (CHAR_HAS_CATEGORY (c
, ' '))
782 p
= BYTE_POS_ADDR (pos_byte
);
791 /* Test whether the line beginning at POS is indented beyond COLUMN.
792 Blank lines are treated as if they had the same indentation as the
796 indented_beyond_p (pos
, pos_byte
, column
)
797 int pos
, pos_byte
, column
;
800 int opoint
= PT
, opoint_byte
= PT_BYTE
;
802 SET_PT_BOTH (pos
, pos_byte
);
803 while (PT
> BEGV
&& FETCH_BYTE (PT_BYTE
) == '\n')
804 scan_newline (PT
- 1, PT_BYTE
- 1, BEGV
, BEGV_BYTE
, -1, 0);
806 val
= position_indentation (PT_BYTE
);
807 SET_PT_BOTH (opoint
, opoint_byte
);
808 return val
>= column
;
811 DEFUN ("move-to-column", Fmove_to_column
, Smove_to_column
, 1, 2, "p",
812 "Move point to column COLUMN in the current line.\n\
813 The column of a character is calculated by adding together the widths\n\
814 as displayed of the previous characters in the line.\n\
815 This function ignores line-continuation;\n\
816 there is no upper limit on the column number a character can have\n\
817 and horizontal scrolling has no effect.\n\
819 If specified column is within a character, point goes after that character.\n\
820 If it's past end of line, point goes to end of line.\n\n\
821 A non-nil second (optional) argument FORCE means, if the line\n\
822 is too short to reach column COLUMN then add spaces/tabs to get there,\n\
823 and if COLUMN is in the middle of a tab character, change it to spaces.\n\
825 The return value is the current column.")
827 Lisp_Object column
, force
;
830 register int col
= current_column ();
833 register int tab_width
= XINT (current_buffer
->tab_width
);
834 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
835 register struct Lisp_Char_Table
*dp
= buffer_display_table ();
836 register int multibyte
= !NILP (current_buffer
->enable_multibyte_characters
);
843 int pos_byte
, end_byte
, next_boundary_byte
;
845 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
846 CHECK_NATNUM (column
, 0);
847 goal
= XINT (column
);
854 next_boundary_byte
= PT_BYTE
;
856 /* If we're starting past the desired column,
857 back up to beginning of line and scan from there. */
861 pos
= current_column_bol_cache
;
862 pos_byte
= CHAR_TO_BYTE (pos
);
868 while (pos
== next_boundary
)
871 pos
= skip_invisible (pos
, &next_boundary
, end
, Qnil
);
873 pos_byte
= CHAR_TO_BYTE (pos
);
874 next_boundary_byte
= CHAR_TO_BYTE (next_boundary
);
879 /* Test reaching the goal column. We do this after skipping
880 invisible characters, so that we put point before the
881 character on which the cursor will appear. */
885 c
= FETCH_BYTE (pos_byte
);
887 && ! (multibyte
&& BASE_LEADING_CODE_P (c
))
888 && VECTORP (DISP_CHAR_VECTOR (dp
, c
)))
890 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
897 if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
905 col
= col
/ tab_width
* tab_width
;
907 else if (ctl_arrow
&& (c
< 040 || c
== 0177))
909 else if (c
< 040 || c
== 0177)
913 else if (multibyte
&& BASE_LEADING_CODE_P (c
))
915 /* Start of multi-byte form. */
917 int bytes
, width
, wide_column
;
920 ptr
= BYTE_POS_ADDR (pos_byte
);
921 MULTIBYTE_BYTES_WIDTH (ptr
, c
, dp
);
930 SET_PT_BOTH (pos
, pos_byte
);
932 /* If a tab char made us overshoot, change it to spaces
933 and scan through it again. */
934 if (!NILP (force
) && col
> goal
&& c
== '\t' && prev_col
< goal
)
936 int old_point
, old_point_byte
;
938 del_range (PT
- 1, PT
);
939 Findent_to (make_number (goal
), Qnil
);
941 old_point_byte
= PT_BYTE
;
942 Findent_to (make_number (col
), Qnil
);
943 SET_PT_BOTH (old_point
, old_point_byte
);
944 /* Set the last_known... vars consistently. */
948 /* If line ends prematurely, add space to the end. */
949 if (col
< goal
&& !NILP (force
))
950 Findent_to (make_number (col
= goal
), Qnil
);
952 last_known_column
= col
;
953 last_known_column_point
= PT
;
954 last_known_column_modified
= MODIFF
;
956 XSETFASTINT (val
, col
);
960 /* compute_motion: compute buffer posn given screen posn and vice versa */
962 struct position val_compute_motion
;
964 /* Scan the current buffer forward from offset FROM, pretending that
965 this is at line FROMVPOS, column FROMHPOS, until reaching buffer
966 offset TO or line TOVPOS, column TOHPOS (whichever comes first),
967 and return the ending buffer position and screen location. If we
968 can't hit the requested column exactly (because of a tab or other
969 multi-column character), overshoot.
971 DID_MOTION is 1 if FROMHPOS has already accounted for overlay strings
972 at FROM. This is the case if FROMVPOS and FROMVPOS came from an
973 earlier call to compute_motion. The other common case is that FROMHPOS
974 is zero and FROM is a position that "belongs" at column zero, but might
975 be shifted by overlay strings; in this case DID_MOTION should be 0.
977 WIDTH is the number of columns available to display text;
978 compute_motion uses this to handle continuation lines and such.
979 HSCROLL is the number of columns not being displayed at the left
980 margin; this is usually taken from a window's hscroll member.
981 TAB_OFFSET is the number of columns of the first tab that aren't
982 being displayed, perhaps because of a continuation line or
985 compute_motion returns a pointer to a struct position. The bufpos
986 member gives the buffer position at the end of the scan, and hpos
987 and vpos give its cartesian location. prevhpos is the column at
988 which the character before bufpos started, and contin is non-zero
989 if we reached the current line by continuing the previous.
991 Note that FROMHPOS and TOHPOS should be expressed in real screen
992 columns, taking HSCROLL and the truncation glyph at the left margin
993 into account. That is, beginning-of-line moves you to the hpos
994 -HSCROLL + (HSCROLL > 0).
996 For example, to find the buffer position of column COL of line LINE
997 of a certain window, pass the window's starting location as FROM
998 and the window's upper-left coordinates as FROMVPOS and FROMHPOS.
999 Pass the buffer's ZV as TO, to limit the scan to the end of the
1000 visible section of the buffer, and pass LINE and COL as TOVPOS and
1003 When displaying in window w, a typical formula for WIDTH is:
1006 - (has_vertical_scroll_bars
1007 ? FRAME_SCROLL_BAR_COLS (XFRAME (window->frame))
1008 : (window_width + window_left != frame_width))
1011 window_width is XFASTINT (w->width),
1012 window_left is XFASTINT (w->left),
1013 has_vertical_scroll_bars is
1014 FRAME_HAS_VERTICAL_SCROLL_BARS (XFRAME (WINDOW_FRAME (window)))
1015 and frame_width = FRAME_WIDTH (XFRAME (window->frame))
1017 Or you can let window_internal_width do this all for you, and write:
1018 window_internal_width (w) - 1
1020 The `-1' accounts for the continuation-line backslashes; the rest
1021 accounts for window borders if the window is split horizontally, and
1022 the scroll bars if they are turned on. */
1025 compute_motion (from
, fromvpos
, fromhpos
, did_motion
, to
, tovpos
, tohpos
, width
, hscroll
, tab_offset
, win
)
1026 int from
, fromvpos
, fromhpos
, to
, tovpos
, tohpos
;
1029 int hscroll
, tab_offset
;
1032 register int hpos
= fromhpos
;
1033 register int vpos
= fromvpos
;
1038 register int tab_width
= XFASTINT (current_buffer
->tab_width
);
1039 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
1040 register struct Lisp_Char_Table
*dp
= window_display_table (win
);
1042 = (INTEGERP (current_buffer
->selective_display
)
1043 ? XINT (current_buffer
->selective_display
)
1044 : !NILP (current_buffer
->selective_display
) ? -1 : 0);
1047 = (selective
&& dp
&& VECTORP (DISP_INVIS_VECTOR (dp
))
1048 ? XVECTOR (DISP_INVIS_VECTOR (dp
))->size
: 0);
1049 /* The next location where the `invisible' property changes, or an
1050 overlay starts or ends. */
1051 int next_boundary
= from
;
1053 /* For computing runs of characters with similar widths.
1054 Invariant: width_run_width is zero, or all the characters
1055 from width_run_start to width_run_end have a fixed width of
1057 int width_run_start
= from
;
1058 int width_run_end
= from
;
1059 int width_run_width
= 0;
1060 Lisp_Object
*width_table
;
1063 /* The next buffer pos where we should consult the width run cache. */
1064 int next_width_run
= from
;
1067 int multibyte
= !NILP (current_buffer
->enable_multibyte_characters
);
1068 /* If previous char scanned was a wide character,
1069 this is the column where it ended. Otherwise, this is 0. */
1070 int wide_column_end_hpos
= 0;
1071 int prev_pos
; /* Previous buffer position. */
1072 int prev_pos_byte
; /* Previous buffer position. */
1073 int contin_hpos
; /* HPOS of last column of continued line. */
1074 int prev_tab_offset
; /* Previous tab offset. */
1076 XSETBUFFER (buffer
, current_buffer
);
1077 XSETWINDOW (window
, win
);
1079 width_run_cache_on_off ();
1080 if (dp
== buffer_display_table ())
1081 width_table
= (VECTORP (current_buffer
->width_table
)
1082 ? XVECTOR (current_buffer
->width_table
)->contents
1085 /* If the window has its own display table, we can't use the width
1086 run cache, because that's based on the buffer's display table. */
1089 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
1091 pos
= prev_pos
= from
;
1092 pos_byte
= prev_pos_byte
= CHAR_TO_BYTE (from
);
1094 prev_tab_offset
= tab_offset
;
1097 while (pos
== next_boundary
)
1102 /* Don't skip invisible if we are already at the margin. */
1103 if (vpos
> tovpos
|| vpos
== tovpos
&& hpos
>= tohpos
)
1105 if (contin_hpos
&& prev_hpos
== 0
1107 && (contin_hpos
== width
|| wide_column_end_hpos
> width
))
1108 { /* Line breaks because we can't put the character at the
1109 previous line any more. It is not the multi-column
1110 character continued in middle. Go back to previous
1111 buffer position, screen position, and set tab offset
1112 to previous value. It's the beginning of the
1115 pos_byte
= prev_pos_byte
;
1117 tab_offset
= prev_tab_offset
;
1122 /* If the caller says that the screen position came from an earlier
1123 call to compute_motion, then we've already accounted for the
1124 overlay strings at point. This is only true the first time
1125 through, so clear the flag after testing it. */
1127 /* We need to skip past the overlay strings. Currently those
1128 strings must not contain TAB;
1129 if we want to relax that restriction, something will have
1130 to be changed here. */
1132 unsigned char *ovstr
;
1133 int ovlen
= overlay_strings (pos
, win
, &ovstr
);
1134 hpos
+= ((multibyte
&& ovlen
> 0)
1135 ? strwidth (ovstr
, ovlen
) : ovlen
);
1142 /* Advance POS past invisible characters
1143 (but not necessarily all that there are here),
1144 and store in next_boundary the next position where
1145 we need to call skip_invisible. */
1146 newpos
= skip_invisible (pos
, &next_boundary
, to
, window
);
1150 pos
= min (to
, newpos
);
1154 if (newpos
!= pos_here
)
1157 pos_byte
= CHAR_TO_BYTE (pos
);
1161 /* Handle right margin. */
1162 /* Note on a wide-column character.
1164 Characters are classified into the following three categories
1165 according to the width (columns occupied on screen).
1167 (1) single-column character: ex. `a'
1168 (2) multi-column character: ex. `^A', TAB, `\033'
1169 (3) wide-column character: ex. Japanese character, Chinese character
1170 (In the following example, `W_' stands for them.)
1172 Multi-column characters can be divided around the right margin,
1173 but wide-column characters cannot.
1177 (*) The cursor is placed on the next character after the point.
1181 j ^---- next after the point
1182 ^--- next char. after the point.
1184 In case of sigle-column character
1188 033 ^---- next after the point, next char. after the point.
1190 In case of multi-column character
1194 W_ ^---- next after the point
1195 ^---- next char. after the point.
1197 In case of wide-column character
1199 The problem here is continuation at a wide-column character.
1200 In this case, the line may shorter less than WIDTH.
1201 And we find the continuation AFTER it occurs.
1208 || (truncate_partial_width_windows
1209 && width
+ 1 < FRAME_WIDTH (XFRAME (WINDOW_FRAME (win
))))
1210 || !NILP (current_buffer
->truncate_lines
))
1212 /* Truncating: skip to newline, unless we are already past
1213 TO (we need to go back below). */
1216 pos
= find_before_next_newline (pos
, to
, 1);
1217 pos_byte
= CHAR_TO_BYTE (pos
);
1219 /* If we just skipped next_boundary,
1220 loop around in the main while
1222 if (pos
>= next_boundary
)
1223 next_boundary
= pos
+ 1;
1225 prev_tab_offset
= tab_offset
;
1231 /* Remember the previous value. */
1232 prev_tab_offset
= tab_offset
;
1234 if (wide_column_end_hpos
> width
)
1237 tab_offset
+= prev_hpos
;
1241 tab_offset
+= width
;
1245 contin_hpos
= prev_hpos
;
1250 /* Stop if past the target buffer position or screen position. */
1253 /* Go back to the previous position. */
1255 pos_byte
= prev_pos_byte
;
1257 tab_offset
= prev_tab_offset
;
1259 /* NOTE on contin_hpos, hpos, and prev_hpos.
1263 W_ ^---- contin_hpos
1269 if (contin_hpos
&& prev_hpos
== 0
1270 && contin_hpos
< width
&& !wide_column_end_hpos
)
1272 /* Line breaking occurs in the middle of multi-column
1273 character. Go back to previous line. */
1278 /* If previous character is NEWLINE,
1279 set VPOS back to previous line */
1284 if (vpos
> tovpos
|| vpos
== tovpos
&& hpos
>= tohpos
)
1286 if (contin_hpos
&& prev_hpos
== 0
1288 && (contin_hpos
== width
|| wide_column_end_hpos
> width
))
1289 { /* Line breaks because we can't put the character at the
1290 previous line any more. It is not the multi-column
1291 character continued in middle. Go back to previous
1292 buffer position, screen position, and set tab offset
1293 to previous value. It's the beginning of the
1296 pos_byte
= prev_pos_byte
;
1298 tab_offset
= prev_tab_offset
;
1302 if (pos
== ZV
) /* We cannot go beyond ZV. Stop here. */
1307 prev_pos_byte
= pos_byte
;
1308 wide_column_end_hpos
= 0;
1310 /* Consult the width run cache to see if we can avoid inspecting
1311 the text character-by-character. */
1312 if (current_buffer
->width_run_cache
&& pos
>= next_width_run
)
1316 = region_cache_forward (current_buffer
,
1317 current_buffer
->width_run_cache
,
1320 /* A width of zero means the character's width varies (like
1321 a tab), is meaningless (like a newline), or we just don't
1322 want to skip over it for some other reason. */
1323 if (common_width
!= 0)
1327 /* Don't go past the final buffer posn the user
1332 run_end_hpos
= hpos
+ (run_end
- pos
) * common_width
;
1334 /* Don't go past the final horizontal position the user
1336 if (vpos
== tovpos
&& run_end_hpos
> tohpos
)
1338 run_end
= pos
+ (tohpos
- hpos
) / common_width
;
1339 run_end_hpos
= hpos
+ (run_end
- pos
) * common_width
;
1342 /* Don't go past the margin. */
1343 if (run_end_hpos
>= width
)
1345 run_end
= pos
+ (width
- hpos
) / common_width
;
1346 run_end_hpos
= hpos
+ (run_end
- pos
) * common_width
;
1349 hpos
= run_end_hpos
;
1351 prev_hpos
= hpos
- common_width
;
1355 pos_byte
= CHAR_TO_BYTE (pos
);
1359 next_width_run
= run_end
+ 1;
1362 /* We have to scan the text character-by-character. */
1365 c
= FETCH_BYTE (pos_byte
);
1368 /* Perhaps add some info to the width_run_cache. */
1369 if (current_buffer
->width_run_cache
)
1371 /* Is this character part of the current run? If so, extend
1373 if (pos
- 1 == width_run_end
1374 && XFASTINT (width_table
[c
]) == width_run_width
)
1375 width_run_end
= pos
;
1377 /* The previous run is over, since this is a character at a
1378 different position, or a different width. */
1381 /* Have we accumulated a run to put in the cache?
1382 (Currently, we only cache runs of width == 1). */
1383 if (width_run_start
< width_run_end
1384 && width_run_width
== 1)
1385 know_region_cache (current_buffer
,
1386 current_buffer
->width_run_cache
,
1387 width_run_start
, width_run_end
);
1389 /* Start recording a new width run. */
1390 width_run_width
= XFASTINT (width_table
[c
]);
1391 width_run_start
= pos
- 1;
1392 width_run_end
= pos
;
1397 && ! (multibyte
&& BASE_LEADING_CODE_P (c
))
1398 && VECTORP (DISP_CHAR_VECTOR (dp
, c
)))
1399 hpos
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
1400 else if (c
>= 040 && c
< 0177)
1404 int tem
= (hpos
+ tab_offset
+ hscroll
- (hscroll
> 0)) % tab_width
;
1407 hpos
+= tab_width
- tem
;
1412 && indented_beyond_p (pos
, pos_byte
, selective
))
1414 /* If (pos == to), we don't have to take care of
1415 selective display. */
1418 /* Skip any number of invisible lines all at once */
1421 pos
= find_before_next_newline (pos
, to
, 1) + 1;
1422 pos_byte
= CHAR_TO_BYTE (pos
);
1425 && indented_beyond_p (pos
, pos_byte
, selective
));
1426 /* Allow for the " ..." that is displayed for them. */
1429 hpos
+= selective_rlen
;
1433 DEC_BOTH (pos
, pos_byte
);
1434 /* We have skipped the invis text, but not the
1440 /* A visible line. */
1444 /* Count the truncation glyph on column 0 */
1451 else if (c
== CR
&& selective
< 0)
1453 /* In selective display mode,
1454 everything from a ^M to the end of the line is invisible.
1455 Stop *before* the real newline. */
1458 pos
= find_before_next_newline (pos
, to
, 1);
1459 pos_byte
= CHAR_TO_BYTE (pos
);
1461 /* If we just skipped next_boundary,
1462 loop around in the main while
1464 if (pos
> next_boundary
)
1465 next_boundary
= pos
;
1466 /* Allow for the " ..." that is displayed for them. */
1469 hpos
+= selective_rlen
;
1474 else if (multibyte
&& BASE_LEADING_CODE_P (c
))
1476 /* Start of multi-byte form. */
1478 int bytes
, width
, wide_column
;
1480 pos_byte
--; /* rewind POS_BYTE */
1481 ptr
= BYTE_POS_ADDR (pos_byte
);
1482 MULTIBYTE_BYTES_WIDTH (ptr
, c
, dp
);
1485 wide_column_end_hpos
= hpos
+ wide_column
;
1489 hpos
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
1495 /* Remember any final width run in the cache. */
1496 if (current_buffer
->width_run_cache
1497 && width_run_width
== 1
1498 && width_run_start
< width_run_end
)
1499 know_region_cache (current_buffer
, current_buffer
->width_run_cache
,
1500 width_run_start
, width_run_end
);
1502 val_compute_motion
.bufpos
= pos
;
1503 val_compute_motion
.bytepos
= pos_byte
;
1504 val_compute_motion
.hpos
= hpos
;
1505 val_compute_motion
.vpos
= vpos
;
1506 if (contin_hpos
&& prev_hpos
== 0)
1507 val_compute_motion
.prevhpos
= contin_hpos
;
1509 val_compute_motion
.prevhpos
= prev_hpos
;
1510 /* We alalways handle all of them here; none of them remain to do. */
1511 val_compute_motion
.ovstring_chars_done
= 0;
1513 /* Nonzero if have just continued a line */
1514 val_compute_motion
.contin
= (contin_hpos
&& prev_hpos
== 0);
1516 return &val_compute_motion
;
1519 #if 0 /* The doc string is too long for some compilers,
1520 but make-docfile can find it in this comment. */
1521 DEFUN ("compute-motion", Ffoo
, Sfoo
, 7, 7, 0,
1522 "Scan through the current buffer, calculating screen position.\n\
1523 Scan the current buffer forward from offset FROM,\n\
1524 assuming it is at position FROMPOS--a cons of the form (HPOS . VPOS)--\n\
1525 to position TO or position TOPOS--another cons of the form (HPOS . VPOS)--\n\
1526 and return the ending buffer position and screen location.\n\
1528 There are three additional arguments:\n\
1530 WIDTH is the number of columns available to display text;\n\
1531 this affects handling of continuation lines.\n\
1532 This is usually the value returned by `window-width', less one (to allow\n\
1533 for the continuation glyph).\n\
1535 OFFSETS is either nil or a cons cell (HSCROLL . TAB-OFFSET).\n\
1536 HSCROLL is the number of columns not being displayed at the left\n\
1537 margin; this is usually taken from a window's hscroll member.\n\
1538 TAB-OFFSET is the number of columns of the first tab that aren't\n\
1539 being displayed, perhaps because the line was continued within it.\n\
1540 If OFFSETS is nil, HSCROLL and TAB-OFFSET are assumed to be zero.\n\
1542 WINDOW is the window to operate on. It is used to choose the display table;\n\
1543 if it is showing the current buffer, it is used also for\n\
1544 deciding which overlay properties apply.\n\
1545 Note that `compute-motion' always operates on the current buffer.\n\
1547 The value is a list of five elements:\n\
1548 (POS HPOS VPOS PREVHPOS CONTIN)\n\
1549 POS is the buffer position where the scan stopped.\n\
1550 VPOS is the vertical position where the scan stopped.\n\
1551 HPOS is the horizontal position where the scan stopped.\n\
1553 PREVHPOS is the horizontal position one character back from POS.\n\
1554 CONTIN is t if a line was continued after (or within) the previous character.\n\
1556 For example, to find the buffer position of column COL of line LINE\n\
1557 of a certain window, pass the window's starting location as FROM\n\
1558 and the window's upper-left coordinates as FROMPOS.\n\
1559 Pass the buffer's (point-max) as TO, to limit the scan to the end of the\n\
1560 visible section of the buffer, and pass LINE and COL as TOPOS.")
1561 (from
, frompos
, to
, topos
, width
, offsets
, window
)
1564 DEFUN ("compute-motion", Fcompute_motion
, Scompute_motion
, 7, 7, 0,
1566 (from
, frompos
, to
, topos
, width
, offsets
, window
)
1567 Lisp_Object from
, frompos
, to
, topos
;
1568 Lisp_Object width
, offsets
, window
;
1570 Lisp_Object bufpos
, hpos
, vpos
, prevhpos
, contin
;
1571 struct position
*pos
;
1572 int hscroll
, tab_offset
;
1574 CHECK_NUMBER_COERCE_MARKER (from
, 0);
1575 CHECK_CONS (frompos
, 0);
1576 CHECK_NUMBER (XCONS (frompos
)->car
, 0);
1577 CHECK_NUMBER (XCONS (frompos
)->cdr
, 0);
1578 CHECK_NUMBER_COERCE_MARKER (to
, 0);
1579 CHECK_CONS (topos
, 0);
1580 CHECK_NUMBER (XCONS (topos
)->car
, 0);
1581 CHECK_NUMBER (XCONS (topos
)->cdr
, 0);
1582 CHECK_NUMBER (width
, 0);
1583 if (!NILP (offsets
))
1585 CHECK_CONS (offsets
, 0);
1586 CHECK_NUMBER (XCONS (offsets
)->car
, 0);
1587 CHECK_NUMBER (XCONS (offsets
)->cdr
, 0);
1588 hscroll
= XINT (XCONS (offsets
)->car
);
1589 tab_offset
= XINT (XCONS (offsets
)->cdr
);
1592 hscroll
= tab_offset
= 0;
1595 window
= Fselected_window ();
1597 CHECK_LIVE_WINDOW (window
, 0);
1599 if (XINT (from
) < BEGV
|| XINT (from
) > ZV
)
1600 args_out_of_range_3 (from
, make_number (BEGV
), make_number (ZV
));
1601 if (XINT (to
) < BEGV
|| XINT (to
) > ZV
)
1602 args_out_of_range_3 (to
, make_number (BEGV
), make_number (ZV
));
1604 pos
= compute_motion (XINT (from
), XINT (XCONS (frompos
)->cdr
),
1605 XINT (XCONS (frompos
)->car
), 0,
1606 XINT (to
), XINT (XCONS (topos
)->cdr
),
1607 XINT (XCONS (topos
)->car
),
1608 XINT (width
), hscroll
, tab_offset
,
1611 XSETFASTINT (bufpos
, pos
->bufpos
);
1612 XSETINT (hpos
, pos
->hpos
);
1613 XSETINT (vpos
, pos
->vpos
);
1614 XSETINT (prevhpos
, pos
->prevhpos
);
1616 return Fcons (bufpos
,
1620 Fcons (pos
->contin
? Qt
: Qnil
, Qnil
)))));
1624 /* Fvertical_motion and vmotion */
1625 struct position val_vmotion
;
1628 vmotion (from
, vtarget
, w
)
1629 register int from
, vtarget
;
1632 int width
= window_internal_width (w
) - 1;
1633 int hscroll
= XINT (w
->hscroll
);
1634 struct position pos
;
1635 /* vpos is cumulative vertical position, changed as from is changed */
1636 register int vpos
= 0;
1637 Lisp_Object prevline
;
1640 int lmargin
= hscroll
> 0 ? 1 - hscroll
: 0;
1642 = (INTEGERP (current_buffer
->selective_display
)
1643 ? XINT (current_buffer
->selective_display
)
1644 : !NILP (current_buffer
->selective_display
) ? -1 : 0);
1648 /* This is the object we use for fetching character properties. */
1649 Lisp_Object text_prop_object
;
1651 XSETWINDOW (window
, w
);
1653 /* The omission of the clause
1654 && marker_position (w->start) == BEG
1655 here is deliberate; I think we want to measure from the prompt
1656 position even if the minibuffer window has scrolled. */
1657 if (EQ (window
, minibuf_window
))
1659 if (minibuf_prompt_width
== 0 && STRINGP (minibuf_prompt
))
1660 minibuf_prompt_width
1661 = string_display_width (minibuf_prompt
, Qnil
, Qnil
);
1663 start_hpos
= minibuf_prompt_width
;
1666 /* If the window contains this buffer, use it for getting text properties.
1667 Otherwise use the current buffer as arg for doing that. */
1668 if (EQ (w
->buffer
, Fcurrent_buffer ()))
1669 text_prop_object
= window
;
1671 text_prop_object
= Fcurrent_buffer ();
1673 if (vpos
>= vtarget
)
1675 /* To move upward, go a line at a time until
1676 we have gone at least far enough. */
1680 while ((vpos
> vtarget
|| first
) && from
> BEGV
)
1682 Lisp_Object propval
;
1684 XSETFASTINT (prevline
, find_next_newline_no_quit (from
- 1, -1));
1685 while (XFASTINT (prevline
) > BEGV
1687 && indented_beyond_p (XFASTINT (prevline
),
1688 CHAR_TO_BYTE (XFASTINT (prevline
)),
1690 #ifdef USE_TEXT_PROPERTIES
1691 /* watch out for newlines with `invisible' property */
1692 || (propval
= Fget_char_property (prevline
,
1695 TEXT_PROP_MEANS_INVISIBLE (propval
))
1698 XSETFASTINT (prevline
,
1699 find_next_newline_no_quit (XFASTINT (prevline
) - 1,
1701 pos
= *compute_motion (XFASTINT (prevline
), 0,
1702 lmargin
+ (XFASTINT (prevline
) == BEG
1706 /* Don't care for VPOS... */
1707 1 << (BITS_PER_SHORT
- 1),
1709 1 << (BITS_PER_SHORT
- 1),
1711 /* This compensates for start_hpos
1712 so that a tab as first character
1713 still occupies 8 columns. */
1714 (XFASTINT (prevline
) == BEG
1719 from
= XFASTINT (prevline
);
1722 /* If we made exactly the desired vertical distance,
1723 or if we hit beginning of buffer,
1724 return point found */
1725 if (vpos
>= vtarget
)
1727 val_vmotion
.bufpos
= from
;
1728 val_vmotion
.bytepos
= CHAR_TO_BYTE (from
);
1729 val_vmotion
.vpos
= vpos
;
1730 val_vmotion
.hpos
= lmargin
;
1731 val_vmotion
.contin
= 0;
1732 val_vmotion
.prevhpos
= 0;
1733 val_vmotion
.ovstring_chars_done
= 0;
1734 val_vmotion
.tab_offset
= 0; /* For accumulating tab offset. */
1735 return &val_vmotion
;
1738 /* Otherwise find the correct spot by moving down */
1740 /* Moving downward is simple, but must calculate from beg of line
1741 to determine hpos of starting point */
1742 from_byte
= CHAR_TO_BYTE (from
);
1743 if (from
> BEGV
&& FETCH_BYTE (from_byte
- 1) != '\n')
1745 Lisp_Object propval
;
1747 XSETFASTINT (prevline
, find_next_newline_no_quit (from
, -1));
1748 while (XFASTINT (prevline
) > BEGV
1750 && indented_beyond_p (XFASTINT (prevline
),
1751 CHAR_TO_BYTE (XFASTINT (prevline
)),
1753 #ifdef USE_TEXT_PROPERTIES
1754 /* watch out for newlines with `invisible' property */
1755 || (propval
= Fget_char_property (prevline
, Qinvisible
,
1757 TEXT_PROP_MEANS_INVISIBLE (propval
))
1760 XSETFASTINT (prevline
,
1761 find_next_newline_no_quit (XFASTINT (prevline
) - 1,
1763 pos
= *compute_motion (XFASTINT (prevline
), 0,
1764 lmargin
+ (XFASTINT (prevline
) == BEG
1768 /* Don't care for VPOS... */
1769 1 << (BITS_PER_SHORT
- 1),
1771 1 << (BITS_PER_SHORT
- 1),
1773 (XFASTINT (prevline
) == BEG
? -start_hpos
: 0),
1779 pos
.hpos
= lmargin
+ (from
== BEG
? start_hpos
: 0);
1784 return compute_motion (from
, vpos
, pos
.hpos
, did_motion
,
1785 ZV
, vtarget
, - (1 << (BITS_PER_SHORT
- 1)),
1787 pos
.tab_offset
- (from
== BEG
? start_hpos
: 0),
1791 DEFUN ("vertical-motion", Fvertical_motion
, Svertical_motion
, 1, 2, 0,
1792 "Move point to start of the screen line LINES lines down.\n\
1793 If LINES is negative, this means moving up.\n\
1795 This function is an ordinary cursor motion function\n\
1796 which calculates the new position based on how text would be displayed.\n\
1797 The new position may be the start of a line,\n\
1798 or just the start of a continuation line.\n\
1799 The function returns number of screen lines moved over;\n\
1800 that usually equals LINES, but may be closer to zero\n\
1801 if beginning or end of buffer was reached.\n\
1803 The optional second argument WINDOW specifies the window to use for\n\
1804 parameters such as width, horizontal scrolling, and so on.\n\
1805 The default is to use the selected window's parameters.\n\
1807 `vertical-motion' always uses the current buffer,\n\
1808 regardless of which buffer is displayed in WINDOW.\n\
1809 This is consistent with other cursor motion functions\n\
1810 and makes it possible to use `vertical-motion' in any buffer,\n\
1811 whether or not it is currently displayed in some window.")
1813 Lisp_Object lines
, window
;
1815 struct position pos
;
1817 CHECK_NUMBER (lines
, 0);
1818 if (! NILP (window
))
1819 CHECK_WINDOW (window
, 0);
1821 window
= selected_window
;
1823 pos
= *vmotion (PT
, (int) XINT (lines
), XWINDOW (window
));
1825 SET_PT (pos
.bufpos
);
1826 return make_number (pos
.vpos
);
1829 /* file's initialization. */
1834 DEFVAR_BOOL ("indent-tabs-mode", &indent_tabs_mode
,
1835 "*Indentation can insert tabs if this is non-nil.\n\
1836 Setting this variable automatically makes it local to the current buffer.");
1837 indent_tabs_mode
= 1;
1839 defsubr (&Scurrent_indentation
);
1840 defsubr (&Sindent_to
);
1841 defsubr (&Scurrent_column
);
1842 defsubr (&Smove_to_column
);
1843 defsubr (&Svertical_motion
);
1844 defsubr (&Scompute_motion
);