1 /* Indentation functions.
2 Copyright (C) 1985, 1986, 1987, 1988, 1993 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
30 #include "intervals.h"
32 /* Indentation can insert tabs if this is non-zero;
33 otherwise always uses spaces */
36 #define min(a, b) ((a) < (b) ? (a) : (b))
37 #define max(a, b) ((a) > (b) ? (a) : (b))
41 /* These three values memoize the current column to avoid recalculation */
42 /* Some things in set last_known_column_point to -1
43 to mark the memoized value as invalid */
44 /* Last value returned by current_column */
45 int last_known_column
;
46 /* Value of point when current_column was called */
47 int last_known_column_point
;
48 /* Value of MODIFF when current_column was called */
49 int last_known_column_modified
;
51 /* Get the display table to use for the current buffer. */
54 buffer_display_table ()
58 thisbuf
= current_buffer
->display_table
;
59 if (XTYPE (thisbuf
) == Lisp_Vector
60 && XVECTOR (thisbuf
)->size
== DISP_TABLE_SIZE
)
61 return XVECTOR (thisbuf
);
62 if (XTYPE (Vstandard_display_table
) == Lisp_Vector
63 && XVECTOR (Vstandard_display_table
)->size
== DISP_TABLE_SIZE
)
64 return XVECTOR (Vstandard_display_table
);
68 DEFUN ("current-column", Fcurrent_column
, Scurrent_column
, 0, 0, 0,
69 "Return the horizontal position of point. Beginning of line is column 0.\n\
70 This is calculated by adding together the widths of all the displayed\n\
71 representations of the character between the start of the previous line\n\
72 and point. (eg control characters will have a width of 2 or 4, tabs\n\
73 will have a variable width)\n\
74 Ignores finite width of frame, which means that this function may return\n\
75 values greater than (frame-width).\n\
76 Whether the line is visible (if `selective-display' is t) has no effect;\n\
77 however, ^M is treated as end of line when `selective-display' is t.")
81 XFASTINT (temp
) = current_column ();
85 /* Cancel any recorded value of the horizontal position. */
87 invalidate_current_column ()
89 last_known_column_point
= 0;
96 register unsigned char *ptr
, *stop
;
97 register int tab_seen
;
100 register int tab_width
= XINT (current_buffer
->tab_width
);
101 int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
102 register struct Lisp_Vector
*dp
= buffer_display_table ();
105 if (point
== last_known_column_point
106 && MODIFF
== last_known_column_modified
)
107 return last_known_column
;
109 /* Make a pointer for decrementing through the chars before point. */
110 ptr
= &FETCH_CHAR (point
- 1) + 1;
111 /* Make a pointer to where consecutive chars leave off,
112 going backwards from point. */
115 else if (point
<= GPT
|| BEGV
> GPT
)
120 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
122 col
= 0, tab_seen
= 0, post_tab
= 0;
128 /* We stopped either for the beginning of the buffer
130 if (ptr
== BEGV_ADDR
)
132 /* It was the gap. Jump back over it. */
135 /* Check whether that brings us to beginning of buffer. */
136 if (BEGV
>= GPT
) break;
140 if (c
>= 040 && c
< 0177
141 && (dp
== 0 || XTYPE (DISP_CHAR_VECTOR (dp
, c
)) != Lisp_Vector
))
147 else if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
152 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
158 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
159 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
161 col
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
166 col
= ((col
+ tab_width
) / tab_width
) * tab_width
;
170 last_known_column
= col
;
171 last_known_column_point
= point
;
172 last_known_column_modified
= MODIFF
;
178 DEFUN ("indent-to", Findent_to
, Sindent_to
, 1, 2, "NIndent to column: ",
179 "Indent from point with tabs and spaces until COLUMN is reached.\n\
180 Optional second argument MIN says always do at least MIN spaces\n\
181 even if that goes past COLUMN; by default, MIN is zero.")
183 Lisp_Object col
, minimum
;
186 register int fromcol
;
187 register int tab_width
= XINT (current_buffer
->tab_width
);
189 CHECK_NUMBER (col
, 0);
191 XFASTINT (minimum
) = 0;
192 CHECK_NUMBER (minimum
, 1);
194 fromcol
= current_column ();
195 mincol
= fromcol
+ XINT (minimum
);
196 if (mincol
< XINT (col
)) mincol
= XINT (col
);
198 if (fromcol
== mincol
)
199 return make_number (mincol
);
201 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
203 if (indent_tabs_mode
)
206 XFASTINT (n
) = mincol
/ tab_width
- fromcol
/ tab_width
;
207 if (XFASTINT (n
) != 0)
209 Finsert_char (make_number ('\t'), n
);
211 fromcol
= (mincol
/ tab_width
) * tab_width
;
215 XFASTINT (col
) = mincol
- fromcol
;
216 Finsert_char (make_number (' '), col
);
218 last_known_column
= mincol
;
219 last_known_column_point
= point
;
220 last_known_column_modified
= MODIFF
;
222 XSETINT (col
, mincol
);
226 DEFUN ("current-indentation", Fcurrent_indentation
, Scurrent_indentation
,
228 "Return the indentation of the current line.\n\
229 This is the horizontal position of the character\n\
230 following any initial whitespace.")
235 XFASTINT (val
) = position_indentation (find_next_newline (point
, -1));
239 position_indentation (pos
)
242 register int column
= 0;
243 register int tab_width
= XINT (current_buffer
->tab_width
);
244 register unsigned char *p
;
245 register unsigned char *stop
;
247 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
249 stop
= &FETCH_CHAR (BUFFER_CEILING_OF (pos
)) + 1;
250 p
= &FETCH_CHAR (pos
);
257 pos
+= p
- &FETCH_CHAR (pos
);
258 p
= &FETCH_CHAR (pos
);
259 stop
= &FETCH_CHAR (BUFFER_CEILING_OF (pos
)) + 1;
267 column
+= tab_width
- column
% tab_width
;
275 /* Test whether the line beginning at POS is indented beyond COLUMN.
276 Blank lines are treated as if they had the same indentation as the
279 indented_beyond_p (pos
, column
)
282 while (pos
> BEGV
&& FETCH_CHAR (pos
) == '\n')
283 pos
= find_next_newline (pos
- 1, -1);
284 return (position_indentation (pos
) >= column
);
287 DEFUN ("move-to-column", Fmove_to_column
, Smove_to_column
, 1, 2, 0,
288 "Move point to column COLUMN in the current line.\n\
289 The column of a character is calculated by adding together the widths\n\
290 as displayed of the previous characters in the line.\n\
291 This function ignores line-continuation;\n\
292 there is no upper limit on the column number a character can have\n\
293 and horizontal scrolling has no effect.\n\
295 If specified column is within a character, point goes after that character.\n\
296 If it's past end of line, point goes to end of line.\n\n\
297 A non-nil second (optional) argument FORCE means, if the line\n\
298 is too short to reach column COLUMN then add spaces/tabs to get there,\n\
299 and if COLUMN is in the middle of a tab character, change it to spaces.")
301 Lisp_Object column
, force
;
304 register int col
= current_column ();
307 register int tab_width
= XINT (current_buffer
->tab_width
);
308 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
309 register struct Lisp_Vector
*dp
= buffer_display_table ();
315 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
316 CHECK_NATNUM (column
, 0);
317 goal
= XINT (column
);
323 /* If we're starting past the desired column,
324 back up to beginning of line and scan from there. */
327 pos
= find_next_newline (pos
, -1);
331 while (col
< goal
&& pos
< end
)
333 c
= FETCH_CHAR (pos
);
336 if (c
== '\r' && EQ (current_buffer
->selective_display
, Qt
))
343 col
= col
/ tab_width
* tab_width
;
345 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
346 col
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
347 else if (ctl_arrow
&& (c
< 040 || c
== 0177))
349 else if (c
< 040 || c
>= 0177)
357 /* If a tab char made us overshoot, change it to spaces
358 and scan through it again. */
359 if (!NILP (force
) && col
> goal
&& c
== '\t' && prev_col
< goal
)
363 del_range (point
- 1, point
);
364 Findent_to (make_number (goal
), Qnil
);
366 Findent_to (make_number (col
), Qnil
);
368 /* Set the last_known... vars consistently. */
372 /* If line ends prematurely, add space to the end. */
373 if (col
< goal
&& !NILP (force
))
374 Findent_to (make_number (col
= goal
), Qnil
);
376 last_known_column
= col
;
377 last_known_column_point
= point
;
378 last_known_column_modified
= MODIFF
;
380 XFASTINT (val
) = col
;
384 struct position val_compute_motion
;
386 /* Scan the current buffer forward from offset FROM, pretending that
387 this is at line FROMVPOS, column FROMHPOS, until reaching buffer
388 offset TO or line TOVPOS, column TOHPOS (whichever comes first),
389 and return the ending buffer position and screen location.
391 WIDTH is the number of columns available to display text;
392 compute_motion uses this to handle continuation lines and such.
393 HSCROLL is the number of columns not being displayed at the left
394 margin; this is usually taken from a window's hscroll member.
395 TAB_OFFSET is the number of columns of the first tab that aren't
396 being displayed, perhaps because of a continuation line or
399 compute_motion returns a pointer to a struct position. The bufpos
400 member gives the buffer position at the end of the scan, and hpos
401 and vpos give its cartesian location. I'm not clear on what the
404 Note that FROMHPOS and TOHPOS should be expressed in real screen
405 columns, taking HSCROLL and the truncation glyph at the left margin
406 into account. That is, beginning-of-line moves you to the hpos
407 -HSCROLL + (HSCROLL > 0).
409 For example, to find the buffer position of column COL of line LINE
410 of a certain window, pass the window's starting location as FROM
411 and the window's upper-left coordinates as FROMVPOS and FROMHPOS.
412 Pass the buffer's ZV as TO, to limit the scan to the end of the
413 visible section of the buffer, and pass LINE and COL as TOVPOS and
416 When displaying in window w, a typical formula for WIDTH is:
419 - (has_vertical_scroll_bars
420 ? VERTICAL_SCROLL_BAR_WIDTH
421 : (window_width + window_left != frame_width))
424 window_width is XFASTINT (w->width),
425 window_left is XFASTINT (w->left),
426 has_vertical_scroll_bars is
427 FRAME_HAS_VERTICAL_SCROLL_BARS (XFRAME (WINDOW_FRAME (window)))
428 and frame_width = FRAME_WIDTH (XFRAME (window->frame))
430 Or you can let window_internal_width do this all for you, and write:
431 window_internal_width (w) - 1
433 The `-1' accounts for the continuation-line backslashes; the rest
434 accounts for window borders if the window is split horizontally, and
435 the scroll bars if they are turned on. */
438 compute_motion (from
, fromvpos
, fromhpos
, to
, tovpos
, tohpos
, width
, hscroll
, tab_offset
, win
)
439 int from
, fromvpos
, fromhpos
, to
, tovpos
, tohpos
;
441 int hscroll
, tab_offset
;
444 register int hpos
= fromhpos
;
445 register int vpos
= fromvpos
;
449 register int tab_width
= XFASTINT (current_buffer
->tab_width
);
450 register int ctl_arrow
= !NILP (current_buffer
->ctl_arrow
);
451 register struct Lisp_Vector
*dp
= window_display_table (win
);
453 = (XTYPE (current_buffer
->selective_display
) == Lisp_Int
454 ? XINT (current_buffer
->selective_display
)
455 : !NILP (current_buffer
->selective_display
) ? -1 : 0);
456 int prev_vpos
, prev_hpos
= 0;
458 = (selective
&& dp
&& XTYPE (DISP_INVIS_VECTOR (dp
)) == Lisp_Vector
459 ? XVECTOR (DISP_INVIS_VECTOR (dp
))->size
: 0);
460 #ifdef USE_TEXT_PROPERTIES
461 /* The next location where the `invisible' property changes */
462 int next_invisible
= from
;
463 Lisp_Object prop
, position
;
466 if (tab_width
<= 0 || tab_width
> 1000) tab_width
= 8;
467 for (pos
= from
; pos
< to
; pos
++)
469 /* Stop if past the target screen position. */
471 || (vpos
== tovpos
&& hpos
>= tohpos
))
477 #ifdef USE_TEXT_PROPERTIES
478 /* if the `invisible' property is set, we can skip to
479 the next property change */
480 while (pos
== next_invisible
&& pos
< to
)
482 XFASTINT (position
) = pos
;
483 prop
= Fget_char_property (position
,
487 Lisp_Object end
, limit
;
489 /* This is just an estimate to give reasonable
490 performance; nothing should go wrong if it is too small. */
491 limit
= Fnext_overlay_change (position
);
492 if (XFASTINT (limit
) > pos
+ 100)
493 XFASTINT (limit
) = pos
+ 100;
494 end
= Fnext_single_property_change (position
, Qinvisible
,
495 Fcurrent_buffer (), limit
);
497 next_invisible
= XINT (end
);
501 pos
= next_invisible
;
507 c
= FETCH_CHAR (pos
);
508 if (c
>= 040 && c
< 0177
509 && (dp
== 0 || XTYPE (DISP_CHAR_VECTOR (dp
, c
)) != Lisp_Vector
))
513 hpos
+= tab_width
- ((hpos
+ tab_offset
+ hscroll
- (hscroll
> 0)
514 /* Add tab_width here to make sure positive.
515 hpos can be negative after continuation
516 but can't be less than -tab_width. */
522 if (selective
> 0 && indented_beyond_p (pos
+ 1, selective
))
524 /* Skip any number of invisible lines all at once */
527 while (++pos
< to
&& FETCH_CHAR (pos
) != '\n');
529 while (pos
< to
&& indented_beyond_p (pos
+ 1, selective
));
530 pos
--; /* Reread the newline on the next pass. */
531 /* Allow for the " ..." that is displayed for them. */
534 hpos
+= selective_rlen
;
538 /* We have skipped the invis text, but not the newline after. */
542 /* A visible line. */
546 if (hscroll
> 0) hpos
++; /* Truncation glyph on column 0 */
550 else if (c
== CR
&& selective
< 0)
552 /* In selective display mode,
553 everything from a ^M to the end of the line is invisible */
554 while (pos
< to
&& FETCH_CHAR (pos
) != '\n') pos
++;
555 /* Stop *before* the real newline. */
557 /* Allow for the " ..." that is displayed for them. */
560 hpos
+= selective_rlen
;
565 else if (dp
!= 0 && XTYPE (DISP_CHAR_VECTOR (dp
, c
)) == Lisp_Vector
)
566 hpos
+= XVECTOR (DISP_CHAR_VECTOR (dp
, c
))->size
;
568 hpos
+= (ctl_arrow
&& c
< 0200) ? 2 : 4;
570 /* Handle right margin. */
574 && FETCH_CHAR (pos
+ 1) != '\n')))
577 || (vpos
== tovpos
&& hpos
>= tohpos
))
580 || (truncate_partial_width_windows
581 && width
+ 1 < FRAME_WIDTH (selected_frame
))
582 || !NILP (current_buffer
->truncate_lines
))
584 /* Truncating: skip to newline. */
585 while (pos
< to
&& FETCH_CHAR (pos
) != '\n') pos
++;
600 val_compute_motion
.bufpos
= pos
;
601 val_compute_motion
.hpos
= hpos
;
602 val_compute_motion
.vpos
= vpos
;
603 val_compute_motion
.prevhpos
= prev_hpos
;
605 /* Nonzero if have just continued a line */
606 val_compute_motion
.contin
608 && (val_compute_motion
.vpos
!= prev_vpos
)
611 return &val_compute_motion
;
614 #if 0 /* The doc string is too long for some compilers,
615 but make-docfile can find it in this comment. */
616 DEFUN ("compute-motion", Ffoo
, Sfoo
, 7, 7, 0,
617 "Scan through the current buffer, calculating screen position.\n\
618 Scan the current buffer forward from offset FROM,\n\
619 assuming it is at position FROMPOS--a cons of the form (HPOS . VPOS)--\n\
620 to position TO or position TOPOS--another cons of the form (HPOS . VPOS)--\n\
621 and return the ending buffer position and screen location.\n\
623 There are three additional arguments:\n\
625 WIDTH is the number of columns available to display text;\n\
626 this affects handling of continuation lines.\n\
627 This is usually the value returned by `window-width', less one (to allow\n\
628 for the continuation glyph).\n\
630 OFFSETS is either nil or a cons cell (HSCROLL . TAB-OFFSET).\n\
631 HSCROLL is the number of columns not being displayed at the left\n\
632 margin; this is usually taken from a window's hscroll member.\n\
633 TAB-OFFSET is the number of columns of the first tab that aren't\n\
634 being displayed, perhaps because the line was continued within it.\n\
635 If OFFSETS is nil, HSCROLL and TAB-OFFSET are assumed to be zero.\n\
637 WINDOW is the window to operate on. Currently this is used only to\n\
638 find the display table. It does not matter what buffer WINDOW displays;\n\
639 `compute-motion' always operates on the current buffer.\n\
641 The value is a list of five elements:\n\
642 (POS HPOS VPOS PREVHPOS CONTIN)\n\
643 POS is the buffer position where the scan stopped.\n\
644 VPOS is the vertical position where the scan stopped.\n\
645 HPOS is the horizontal position where the scan stopped.\n\
647 PREVHPOS is the horizontal position one character back from POS.\n\
648 CONTIN is t if a line was continued after (or within) the previous character.\n\
650 For example, to find the buffer position of column COL of line LINE\n\
651 of a certain window, pass the window's starting location as FROM\n\
652 and the window's upper-left coordinates as FROMPOS.\n\
653 Pass the buffer's (point-max) as TO, to limit the scan to the end of the\n\
654 visible section of the buffer, and pass LINE and COL as TOPOS.")
657 DEFUN ("compute-motion", Fcompute_motion
, Scompute_motion
, 7, 7, 0,
659 (from
, frompos
, to
, topos
, width
, offsets
, window
)
660 Lisp_Object from
, frompos
, to
, topos
;
661 Lisp_Object width
, offsets
, window
;
663 Lisp_Object bufpos
, hpos
, vpos
, prevhpos
, contin
;
664 struct position
*pos
;
665 int hscroll
, tab_offset
;
667 CHECK_NUMBER_COERCE_MARKER (from
, 0);
668 CHECK_CONS (frompos
, 0);
669 CHECK_NUMBER (XCONS (frompos
)->car
, 0);
670 CHECK_NUMBER (XCONS (frompos
)->cdr
, 0);
671 CHECK_NUMBER_COERCE_MARKER (to
, 0);
672 CHECK_CONS (topos
, 0);
673 CHECK_NUMBER (XCONS (topos
)->car
, 0);
674 CHECK_NUMBER (XCONS (topos
)->cdr
, 0);
675 CHECK_NUMBER (width
, 0);
678 CHECK_CONS (offsets
, 0);
679 CHECK_NUMBER (XCONS (offsets
)->car
, 0);
680 CHECK_NUMBER (XCONS (offsets
)->cdr
, 0);
681 hscroll
= XINT (XCONS (offsets
)->car
);
682 tab_offset
= XINT (XCONS (offsets
)->cdr
);
685 hscroll
= tab_offset
= 0;
688 window
= Fselected_window ();
690 CHECK_LIVE_WINDOW (window
, 0);
692 pos
= compute_motion (XINT (from
), XINT (XCONS (frompos
)->cdr
),
693 XINT (XCONS (frompos
)->car
),
694 XINT (to
), XINT (XCONS (topos
)->cdr
),
695 XINT (XCONS (topos
)->car
),
696 XINT (width
), hscroll
, tab_offset
,
699 XFASTINT (bufpos
) = pos
->bufpos
;
700 XSET (hpos
, Lisp_Int
, pos
->hpos
);
701 XSET (vpos
, Lisp_Int
, pos
->vpos
);
702 XSET (prevhpos
, Lisp_Int
, pos
->prevhpos
);
704 return Fcons (bufpos
,
708 Fcons (pos
->contin
? Qt
: Qnil
, Qnil
)))));
712 /* Return the column of position POS in window W's buffer,
713 rounded down to a multiple of the internal width of W.
714 This is the amount of indentation of position POS
715 that is not visible in its horizontal position in the window. */
718 pos_tab_offset (w
, pos
)
724 int width
= window_internal_width (w
) - 1;
726 if (pos
== BEGV
|| FETCH_CHAR (pos
- 1) == '\n')
729 col
= current_column ();
731 return col
- (col
% width
);
734 /* start_hpos is the hpos of the first character of the buffer:
735 zero except for the minibuffer window,
736 where it is the width of the prompt. */
738 struct position val_vmotion
;
741 vmotion (from
, vtarget
, width
, hscroll
, window
)
742 register int from
, vtarget
, width
;
747 /* vpos is cumulative vertical position, changed as from is changed */
748 register int vpos
= 0;
749 register int prevline
;
751 int lmargin
= hscroll
> 0 ? 1 - hscroll
: 0;
753 = XTYPE (current_buffer
->selective_display
) == Lisp_Int
754 ? XINT (current_buffer
->selective_display
)
755 : !NILP (current_buffer
->selective_display
) ? -1 : 0;
756 /* The omission of the clause
757 && marker_position (XWINDOW (window)->start) == BEG
758 here is deliberate; I think we want to measure from the prompt
759 position even if the minibuffer window has scrolled. */
760 int start_hpos
= (EQ (window
, minibuf_window
) ? minibuf_prompt_width
: 0);
765 /* Moving downward is simple, but must calculate from beg of line
766 to determine hpos of starting point */
767 if (from
> BEGV
&& FETCH_CHAR (from
- 1) != '\n')
769 prevline
= find_next_newline (from
, -1);
770 while (prevline
> BEGV
772 && indented_beyond_p (prevline
, selective
))
773 #ifdef USE_TEXT_PROPERTIES
774 /* watch out for newlines with `invisible' property */
775 || ! NILP (Fget_char_property (XFASTINT (prevline
),
780 prevline
= find_next_newline (prevline
- 1, -1);
781 pos
= *compute_motion (prevline
, 0,
782 lmargin
+ (prevline
== 1 ? start_hpos
: 0),
783 from
, 1 << (INTBITS
- 2), 0,
784 width
, hscroll
, 0, XWINDOW (window
));
788 pos
.hpos
= lmargin
+ (from
== 1 ? start_hpos
: 0);
791 return compute_motion (from
, vpos
, pos
.hpos
,
792 ZV
, vtarget
, - (1 << (INTBITS
- 2)),
793 width
, hscroll
, pos
.vpos
* width
,
797 /* To move upward, go a line at a time until
798 we have gone at least far enough */
802 while ((vpos
> vtarget
|| first
) && from
> BEGV
)
807 prevline
= find_next_newline (prevline
- 1, -1);
810 || ! indented_beyond_p (prevline
, selective
))
811 #ifdef USE_TEXT_PROPERTIES
812 /* watch out for newlines with `invisible' property */
813 && NILP (Fget_char_property (XFASTINT (prevline
),
820 pos
= *compute_motion (prevline
, 0,
821 lmargin
+ (prevline
== 1 ? start_hpos
: 0),
822 from
, 1 << (INTBITS
- 2), 0,
823 width
, hscroll
, 0, XWINDOW (window
));
829 /* If we made exactly the desired vertical distance,
830 or if we hit beginning of buffer,
831 return point found */
834 val_vmotion
.bufpos
= from
;
835 val_vmotion
.vpos
= vpos
;
836 val_vmotion
.hpos
= lmargin
;
837 val_vmotion
.contin
= 0;
838 val_vmotion
.prevhpos
= 0;
842 /* Otherwise find the correct spot by moving down */
846 DEFUN ("vertical-motion", Fvertical_motion
, Svertical_motion
, 1, 2, 0,
847 "Move to start of screen line LINES lines down.\n\
848 If LINES is negative, this is moving up.\n\
850 The optional second argument WINDOW specifies the window to use for\n\
851 parameters such as width, horizontal scrolling, and so on.\n\
852 the default is the selected window.\n\
853 It does not matter what buffer is displayed in WINDOW.\n\
854 `vertical-motion' always uses the current buffer.\n\
856 Sets point to position found; this may be start of line\n\
857 or just the start of a continuation line.\n\
858 Returns number of lines moved; may be closer to zero than LINES\n\
859 if beginning or end of buffer was reached.")
861 Lisp_Object lines
, window
;
864 register struct window
*w
;
866 CHECK_NUMBER (lines
, 0);
868 CHECK_WINDOW (window
, 0);
870 XSET (window
, Lisp_Window
, selected_window
);
872 w
= XWINDOW (window
);
874 pos
= *vmotion (point
, XINT (lines
), window_internal_width (w
) - 1,
875 /* Not XFASTINT since perhaps could be negative */
876 XINT (w
->hscroll
), window
);
879 return make_number (pos
.vpos
);
884 DEFVAR_BOOL ("indent-tabs-mode", &indent_tabs_mode
,
885 "*Indentation can insert tabs if this is non-nil.\n\
886 Setting this variable automatically makes it local to the current buffer.");
887 indent_tabs_mode
= 1;
889 defsubr (&Scurrent_indentation
);
890 defsubr (&Sindent_to
);
891 defsubr (&Scurrent_column
);
892 defsubr (&Smove_to_column
);
893 defsubr (&Svertical_motion
);
894 defsubr (&Scompute_motion
);