Commit | Line | Data |
---|---|---|
993b6404 | 1 | /* Indentation functions. |
70ee42f7 | 2 | Copyright (C) 1985, 1986, 1987, 1988, 1992 Free Software Foundation, Inc. |
993b6404 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
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) | |
9 | any later version. | |
10 | ||
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. | |
15 | ||
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. */ | |
19 | ||
20 | ||
21 | #include "config.h" | |
22 | #include "lisp.h" | |
23 | #include "buffer.h" | |
24 | #include "indent.h" | |
502b9b64 | 25 | #include "frame.h" |
993b6404 JB |
26 | #include "window.h" |
27 | #include "termchar.h" | |
28 | #include "termopts.h" | |
29 | #include "disptab.h" | |
30 | ||
31 | /* Indentation can insert tabs if this is non-zero; | |
32 | otherwise always uses spaces */ | |
33 | int indent_tabs_mode; | |
34 | ||
35 | #define min(a, b) ((a) < (b) ? (a) : (b)) | |
36 | #define max(a, b) ((a) > (b) ? (a) : (b)) | |
37 | ||
38 | #define CR 015 | |
39 | ||
40 | /* These three values memoize the current column to avoid recalculation */ | |
41 | /* Some things in set last_known_column_point to -1 | |
42 | to mark the memoized value as invalid */ | |
43 | /* Last value returned by current_column */ | |
44 | int last_known_column; | |
45 | /* Value of point when current_column was called */ | |
46 | int last_known_column_point; | |
47 | /* Value of MODIFF when current_column was called */ | |
48 | int last_known_column_modified; | |
49 | ||
993b6404 JB |
50 | /* Get the display table to use for the current buffer. */ |
51 | ||
52 | struct Lisp_Vector * | |
53 | buffer_display_table () | |
54 | { | |
55 | Lisp_Object thisbuf; | |
56 | ||
57 | thisbuf = current_buffer->display_table; | |
58 | if (XTYPE (thisbuf) == Lisp_Vector | |
59 | && XVECTOR (thisbuf)->size == DISP_TABLE_SIZE) | |
60 | return XVECTOR (thisbuf); | |
61 | if (XTYPE (Vstandard_display_table) == Lisp_Vector | |
62 | && XVECTOR (Vstandard_display_table)->size == DISP_TABLE_SIZE) | |
63 | return XVECTOR (Vstandard_display_table); | |
64 | return 0; | |
65 | } | |
66 | \f | |
67 | DEFUN ("current-column", Fcurrent_column, Scurrent_column, 0, 0, 0, | |
68 | "Return the horizontal position of point. Beginning of line is column 0.\n\ | |
69 | This is calculated by adding together the widths of all the displayed\n\ | |
70 | representations of the character between the start of the previous line\n\ | |
71 | and point. (eg control characters will have a width of 2 or 4, tabs\n\ | |
72 | will have a variable width)\n\ | |
502b9b64 JB |
73 | Ignores finite width of frame, which means that this function may return\n\ |
74 | values greater than (frame-width).\n\ | |
993b6404 JB |
75 | Whether the line is visible (if `selective-display' is t) has no effect;\n\ |
76 | however, ^M is treated as end of line when `selective-display' is t.") | |
77 | () | |
78 | { | |
79 | Lisp_Object temp; | |
80 | XFASTINT (temp) = current_column (); | |
81 | return temp; | |
82 | } | |
83 | ||
e74928fc JB |
84 | /* Cancel any recorded value of the horizontal position. */ |
85 | ||
86 | invalidate_current_column () | |
87 | { | |
88 | last_known_column_point = 0; | |
89 | } | |
90 | ||
993b6404 JB |
91 | int |
92 | current_column () | |
93 | { | |
94 | register int col; | |
95 | register unsigned char *ptr, *stop; | |
96 | register int tab_seen; | |
97 | int post_tab; | |
98 | register int c; | |
99 | register int tab_width = XINT (current_buffer->tab_width); | |
56a98455 | 100 | int ctl_arrow = !NILP (current_buffer->ctl_arrow); |
993b6404 JB |
101 | register struct Lisp_Vector *dp = buffer_display_table (); |
102 | int stopchar; | |
103 | ||
104 | if (point == last_known_column_point | |
105 | && MODIFF == last_known_column_modified) | |
106 | return last_known_column; | |
107 | ||
108 | /* Make a pointer for decrementing through the chars before point. */ | |
109 | ptr = &FETCH_CHAR (point - 1) + 1; | |
110 | /* Make a pointer to where consecutive chars leave off, | |
111 | going backwards from point. */ | |
112 | if (point == BEGV) | |
113 | stop = ptr; | |
114 | else if (point <= GPT || BEGV > GPT) | |
115 | stop = BEGV_ADDR; | |
116 | else | |
117 | stop = GAP_END_ADDR; | |
118 | ||
119 | if (tab_width <= 0 || tab_width > 20) tab_width = 8; | |
120 | ||
121 | col = 0, tab_seen = 0, post_tab = 0; | |
122 | ||
123 | while (1) | |
124 | { | |
125 | if (ptr == stop) | |
126 | { | |
127 | /* We stopped either for the beginning of the buffer | |
128 | or for the gap. */ | |
129 | if (ptr == BEGV_ADDR) | |
130 | break; | |
131 | /* It was the gap. Jump back over it. */ | |
132 | stop = BEGV_ADDR; | |
133 | ptr = GPT_ADDR; | |
134 | /* Check whether that brings us to beginning of buffer. */ | |
135 | if (BEGV >= GPT) break; | |
136 | } | |
137 | ||
138 | c = *--ptr; | |
139 | if (c >= 040 && c < 0177 | |
140 | && (dp == 0 || XTYPE (DISP_CHAR_ROPE (dp, c)) != Lisp_String)) | |
141 | { | |
142 | col++; | |
143 | } | |
144 | else if (c == '\n') | |
145 | break; | |
146 | else if (c == '\r' && EQ (current_buffer->selective_display, Qt)) | |
147 | break; | |
148 | else if (c == '\t') | |
149 | { | |
150 | if (tab_seen) | |
151 | col = ((col + tab_width) / tab_width) * tab_width; | |
152 | ||
153 | post_tab += col; | |
154 | col = 0; | |
155 | tab_seen = 1; | |
156 | } | |
157 | else if (dp != 0 && XTYPE (DISP_CHAR_ROPE (dp, c)) == Lisp_String) | |
158 | col += XSTRING (DISP_CHAR_ROPE (dp, c))->size / sizeof (GLYPH); | |
159 | else | |
160 | col += (ctl_arrow && c < 0200) ? 2 : 4; | |
161 | } | |
162 | ||
163 | if (tab_seen) | |
164 | { | |
165 | col = ((col + tab_width) / tab_width) * tab_width; | |
166 | col += post_tab; | |
167 | } | |
168 | ||
169 | last_known_column = col; | |
170 | last_known_column_point = point; | |
171 | last_known_column_modified = MODIFF; | |
172 | ||
173 | return col; | |
174 | } | |
175 | \f | |
176 | ||
177 | DEFUN ("indent-to", Findent_to, Sindent_to, 1, 2, "NIndent to column: ", | |
178 | "Indent from point with tabs and spaces until COLUMN is reached.\n\ | |
179 | Optional second argument MIN says always do at least MIN spaces\n\ | |
180 | even if that goes past COLUMN; by default, MIN is zero.") | |
181 | (col, minimum) | |
182 | Lisp_Object col, minimum; | |
183 | { | |
184 | int mincol; | |
185 | register int fromcol; | |
186 | register int tab_width = XINT (current_buffer->tab_width); | |
187 | ||
188 | CHECK_NUMBER (col, 0); | |
56a98455 | 189 | if (NILP (minimum)) |
993b6404 JB |
190 | XFASTINT (minimum) = 0; |
191 | CHECK_NUMBER (minimum, 1); | |
192 | ||
193 | fromcol = current_column (); | |
194 | mincol = fromcol + XINT (minimum); | |
195 | if (mincol < XINT (col)) mincol = XINT (col); | |
196 | ||
197 | if (fromcol == mincol) | |
198 | return make_number (mincol); | |
199 | ||
200 | if (tab_width <= 0 || tab_width > 20) tab_width = 8; | |
201 | ||
202 | if (indent_tabs_mode) | |
203 | { | |
204 | Lisp_Object n; | |
205 | XFASTINT (n) = mincol / tab_width - fromcol / tab_width; | |
206 | if (XFASTINT (n) != 0) | |
207 | { | |
208 | Finsert_char (make_number ('\t'), n); | |
209 | ||
210 | fromcol = (mincol / tab_width) * tab_width; | |
211 | } | |
212 | } | |
213 | ||
214 | XFASTINT (col) = mincol - fromcol; | |
215 | Finsert_char (make_number (' '), col); | |
216 | ||
217 | last_known_column = mincol; | |
218 | last_known_column_point = point; | |
219 | last_known_column_modified = MODIFF; | |
220 | ||
221 | XSETINT (col, mincol); | |
222 | return col; | |
223 | } | |
224 | \f | |
225 | DEFUN ("current-indentation", Fcurrent_indentation, Scurrent_indentation, | |
226 | 0, 0, 0, | |
227 | "Return the indentation of the current line.\n\ | |
228 | This is the horizontal position of the character\n\ | |
229 | following any initial whitespace.") | |
230 | () | |
231 | { | |
232 | Lisp_Object val; | |
233 | ||
234 | XFASTINT (val) = position_indentation (find_next_newline (point, -1)); | |
235 | return val; | |
236 | } | |
237 | ||
238 | position_indentation (pos) | |
239 | register int pos; | |
240 | { | |
241 | register int column = 0; | |
242 | register int tab_width = XINT (current_buffer->tab_width); | |
243 | register unsigned char *p; | |
244 | register unsigned char *stop; | |
245 | ||
246 | if (tab_width <= 0 || tab_width > 20) tab_width = 8; | |
247 | ||
248 | stop = &FETCH_CHAR (BUFFER_CEILING_OF (pos)) + 1; | |
249 | p = &FETCH_CHAR (pos); | |
250 | while (1) | |
251 | { | |
252 | while (p == stop) | |
253 | { | |
254 | if (pos == ZV) | |
255 | return column; | |
256 | pos += p - &FETCH_CHAR (pos); | |
257 | p = &FETCH_CHAR (pos); | |
258 | stop = &FETCH_CHAR (BUFFER_CEILING_OF (pos)) + 1; | |
259 | } | |
260 | switch (*p++) | |
261 | { | |
262 | case ' ': | |
263 | column++; | |
264 | break; | |
265 | case '\t': | |
266 | column += tab_width - column % tab_width; | |
267 | break; | |
268 | default: | |
269 | return column; | |
270 | } | |
271 | } | |
272 | } | |
273 | \f | |
274 | DEFUN ("move-to-column", Fmove_to_column, Smove_to_column, 1, 2, 0, | |
275 | "Move point to column COLUMN in the current line.\n\ | |
276 | The column of a character is calculated by adding together the widths\n\ | |
277 | as displayed of the previous characters in the line.\n\ | |
278 | This function ignores line-continuation;\n\ | |
279 | there is no upper limit on the column number a character can have\n\ | |
230a4cbd JB |
280 | and horizontal scrolling has no effect.\n\ |
281 | \n\ | |
993b6404 JB |
282 | If specified column is within a character, point goes after that character.\n\ |
283 | If it's past end of line, point goes to end of line.\n\n\ | |
284 | A non-nil second (optional) argument FORCE means, if the line\n\ | |
285 | is too short to reach column COLUMN then add spaces/tabs to get there,\n\ | |
286 | and if COLUMN is in the middle of a tab character, change it to spaces.") | |
287 | (column, force) | |
288 | Lisp_Object column, force; | |
289 | { | |
290 | register int pos; | |
291 | register int col = current_column (); | |
292 | register int goal; | |
293 | register int end; | |
294 | register int tab_width = XINT (current_buffer->tab_width); | |
56a98455 | 295 | register int ctl_arrow = !NILP (current_buffer->ctl_arrow); |
993b6404 JB |
296 | register struct Lisp_Vector *dp = buffer_display_table (); |
297 | ||
298 | Lisp_Object val; | |
299 | int prev_col; | |
300 | int c; | |
301 | ||
302 | if (tab_width <= 0 || tab_width > 20) tab_width = 8; | |
303 | CHECK_NATNUM (column, 0); | |
304 | goal = XINT (column); | |
305 | ||
306 | retry: | |
307 | pos = point; | |
308 | end = ZV; | |
309 | ||
310 | /* If we're starting past the desired column, | |
311 | back up to beginning of line and scan from there. */ | |
312 | if (col > goal) | |
313 | { | |
314 | pos = find_next_newline (pos, -1); | |
315 | col = 0; | |
316 | } | |
317 | ||
318 | while (col < goal && pos < end) | |
319 | { | |
320 | c = FETCH_CHAR (pos); | |
321 | if (c == '\n') | |
322 | break; | |
323 | if (c == '\r' && EQ (current_buffer->selective_display, Qt)) | |
324 | break; | |
325 | pos++; | |
326 | if (c == '\t') | |
327 | { | |
328 | prev_col = col; | |
329 | col += tab_width; | |
330 | col = col / tab_width * tab_width; | |
331 | } | |
332 | else if (dp != 0 && XTYPE (DISP_CHAR_ROPE (dp, c)) == Lisp_String) | |
333 | col += XSTRING (DISP_CHAR_ROPE (dp, c))->size / sizeof (GLYPH); | |
334 | else if (ctl_arrow && (c < 040 || c == 0177)) | |
335 | col++; | |
336 | else if (c < 040 || c >= 0177) | |
337 | col += 3; | |
338 | else | |
339 | col++; | |
340 | } | |
341 | ||
342 | SET_PT (pos); | |
343 | ||
344 | /* If a tab char made us overshoot, change it to spaces | |
345 | and scan through it again. */ | |
56a98455 | 346 | if (!NILP (force) && col > goal && c == '\t' && prev_col < goal) |
993b6404 | 347 | { |
70ee42f7 JB |
348 | int old_point; |
349 | ||
993b6404 | 350 | del_range (point - 1, point); |
70ee42f7 JB |
351 | Findent_to (make_number (goal), Qnil); |
352 | old_point = point; | |
353 | Findent_to (make_number (col), Qnil); | |
354 | SET_PT (old_point); | |
993b6404 JB |
355 | } |
356 | ||
357 | /* If line ends prematurely, add space to the end. */ | |
56a98455 | 358 | if (col < goal && !NILP (force)) |
230a4cbd | 359 | Findent_to (make_number (col = goal), Qnil); |
993b6404 JB |
360 | |
361 | last_known_column = col; | |
362 | last_known_column_point = point; | |
363 | last_known_column_modified = MODIFF; | |
364 | ||
365 | XFASTINT (val) = col; | |
366 | return val; | |
367 | } | |
368 | \f | |
369 | struct position val_compute_motion; | |
370 | ||
371 | /* Scan the current buffer forward from offset FROM, pretending that | |
372 | this is at line FROMVPOS, column FROMHPOS, until reaching buffer | |
373 | offset TO or line TOVPOS, column TOHPOS (whichever comes first), | |
374 | and return the ending buffer position and screen location. | |
375 | ||
376 | WIDTH is the number of columns available to display text; | |
377 | compute_motion uses this to handle continuation lines and such. | |
378 | HSCROLL is the number of columns not being displayed at the left | |
379 | margin; this is usually taken from a window's hscroll member. | |
a9764248 JB |
380 | TAB_OFFSET is the number of columns of the first tab that aren't |
381 | being displayed, perhaps because of a continuation line or | |
382 | something. | |
993b6404 JB |
383 | |
384 | compute_motion returns a pointer to a struct position. The bufpos | |
385 | member gives the buffer position at the end of the scan, and hpos | |
386 | and vpos give its cartesian location. I'm not clear on what the | |
387 | other members are. | |
388 | ||
389 | For example, to find the buffer position of column COL of line LINE | |
390 | of a certain window, pass the window's starting location as FROM | |
391 | and the window's upper-left coordinates as FROMVPOS and FROMHPOS. | |
392 | Pass the buffer's ZV as TO, to limit the scan to the end of the | |
393 | visible section of the buffer, and pass LINE and COL as TOVPOS and | |
394 | TOHPOS. | |
395 | ||
396 | When displaying in window w, a typical formula for WIDTH is: | |
397 | ||
398 | window_width - 1 | |
fa61c701 JB |
399 | - (has_vertical_scrollbars |
400 | ? VERTICAL_SCROLLBAR_WIDTH | |
401 | : (window_width + window_left != frame_width)) | |
993b6404 JB |
402 | |
403 | where | |
404 | window_width is XFASTINT (w->width), | |
405 | window_left is XFASTINT (w->left), | |
fa61c701 JB |
406 | has_vertical_scrollbars is |
407 | FRAME_HAS_VERTICAL_SCROLLBARS (XFRAME (WINDOW_FRAME (window))) | |
408 | and frame_width = FRAME_WIDTH (XFRAME (window->frame)) | |
993b6404 | 409 | |
fa61c701 JB |
410 | Or, |
411 | window_internal_width (w) - 1 | |
412 | ||
413 | The `-1' accounts for the continuation-line backslashes; the rest | |
414 | accounts for window borders if the window is split vertically, and | |
415 | the scrollbars if the frame supports them. */ | |
993b6404 JB |
416 | |
417 | struct position * | |
418 | compute_motion (from, fromvpos, fromhpos, to, tovpos, tohpos, width, hscroll, tab_offset) | |
419 | int from, fromvpos, fromhpos, to, tovpos, tohpos; | |
420 | register int width; | |
421 | int hscroll, tab_offset; | |
422 | { | |
cde9337b JB |
423 | register int hpos = fromhpos; |
424 | register int vpos = fromvpos; | |
425 | ||
993b6404 JB |
426 | register int pos; |
427 | register int c; | |
428 | register int tab_width = XFASTINT (current_buffer->tab_width); | |
56a98455 | 429 | register int ctl_arrow = !NILP (current_buffer->ctl_arrow); |
993b6404 JB |
430 | register struct Lisp_Vector *dp = buffer_display_table (); |
431 | int selective | |
432 | = XTYPE (current_buffer->selective_display) == Lisp_Int | |
433 | ? XINT (current_buffer->selective_display) | |
56a98455 | 434 | : !NILP (current_buffer->selective_display) ? -1 : 0; |
cde9337b | 435 | int prev_vpos, prev_hpos; |
993b6404 JB |
436 | int selective_rlen |
437 | = (selective && dp && XTYPE (DISP_INVIS_ROPE (dp)) == Lisp_String | |
438 | ? XSTRING (DISP_INVIS_ROPE (dp))->size / sizeof (GLYPH) : 0); | |
439 | ||
440 | if (tab_width <= 0 || tab_width > 20) tab_width = 8; | |
cde9337b | 441 | for (pos = from; pos < to; pos++) |
993b6404 | 442 | { |
cde9337b JB |
443 | /* Stop if past the target screen position. */ |
444 | if (vpos > tovpos | |
445 | || (vpos == tovpos && hpos >= tohpos)) | |
446 | break; | |
447 | ||
448 | prev_vpos = vpos; | |
449 | prev_hpos = hpos; | |
450 | ||
993b6404 JB |
451 | c = FETCH_CHAR (pos); |
452 | if (c >= 040 && c < 0177 | |
453 | && (dp == 0 || XTYPE (DISP_CHAR_ROPE (dp, c)) != Lisp_String)) | |
cde9337b | 454 | hpos++; |
993b6404 JB |
455 | else if (c == '\t') |
456 | { | |
cde9337b JB |
457 | hpos += tab_width - ((hpos + tab_offset + hscroll - (hscroll > 0) |
458 | /* Add tab_width here to make sure positive. | |
459 | hpos can be negative after continuation | |
460 | but can't be less than -tab_width. */ | |
461 | + tab_width) | |
462 | % tab_width); | |
993b6404 JB |
463 | } |
464 | else if (c == '\n') | |
465 | { | |
466 | if (selective > 0 && position_indentation (pos + 1) >= selective) | |
467 | { | |
468 | /* Skip any number of invisible lines all at once */ | |
469 | do | |
470 | { | |
cde9337b | 471 | while (++pos < to && FETCH_CHAR (pos) != '\n'); |
993b6404 | 472 | } |
e51eab7c | 473 | while (pos < to && position_indentation (pos + 1) >= selective); |
993b6404 JB |
474 | pos--; |
475 | /* Allow for the " ..." that is displayed for them. */ | |
476 | if (selective_rlen) | |
477 | { | |
cde9337b JB |
478 | hpos += selective_rlen; |
479 | if (hpos >= width) | |
480 | hpos = width; | |
993b6404 | 481 | } |
e51eab7c | 482 | /* We have skipped the invis text, but not the newline after. */ |
993b6404 JB |
483 | } |
484 | else | |
cde9337b JB |
485 | { |
486 | /* A visible line. */ | |
487 | vpos++; | |
488 | hpos = 0; | |
46947372 JB |
489 | hpos -= hscroll; |
490 | if (hscroll > 0) hpos++; /* Count the ! on column 0 */ | |
491 | tab_offset = 0; | |
492 | } | |
993b6404 JB |
493 | } |
494 | else if (c == CR && selective < 0) | |
495 | { | |
496 | /* In selective display mode, | |
497 | everything from a ^M to the end of the line is invisible */ | |
cde9337b JB |
498 | while (pos < to && FETCH_CHAR (pos) != '\n') pos++; |
499 | /* Stop *before* the real newline. */ | |
993b6404 JB |
500 | pos--; |
501 | /* Allow for the " ..." that is displayed for them. */ | |
502 | if (selective_rlen) | |
503 | { | |
cde9337b JB |
504 | hpos += selective_rlen; |
505 | if (hpos >= width) | |
506 | hpos = width; | |
993b6404 JB |
507 | } |
508 | } | |
509 | else if (dp != 0 && XTYPE (DISP_CHAR_ROPE (dp, c)) == Lisp_String) | |
cde9337b | 510 | hpos += XSTRING (DISP_CHAR_ROPE (dp, c))->size / sizeof (GLYPH); |
993b6404 | 511 | else |
cde9337b | 512 | hpos += (ctl_arrow && c < 0200) ? 2 : 4; |
993b6404 | 513 | |
cde9337b JB |
514 | /* Handle right margin. */ |
515 | if (hpos >= width | |
516 | && (hpos > width | |
517 | || (pos < ZV - 1 | |
993b6404 JB |
518 | && FETCH_CHAR (pos + 1) != '\n'))) |
519 | { | |
cde9337b JB |
520 | if (vpos > tovpos |
521 | || (vpos == tovpos && hpos >= tohpos)) | |
993b6404 JB |
522 | break; |
523 | if (hscroll | |
524 | || (truncate_partial_width_windows | |
502b9b64 | 525 | && width + 1 < FRAME_WIDTH (selected_frame)) |
56a98455 | 526 | || !NILP (current_buffer->truncate_lines)) |
993b6404 | 527 | { |
cde9337b JB |
528 | /* Truncating: skip to newline. */ |
529 | while (pos < to && FETCH_CHAR (pos) != '\n') pos++; | |
993b6404 | 530 | pos--; |
e51eab7c | 531 | hpos = width; |
993b6404 JB |
532 | } |
533 | else | |
534 | { | |
cde9337b JB |
535 | /* Continuing. */ |
536 | vpos++; | |
537 | hpos -= width; | |
993b6404 JB |
538 | tab_offset += width; |
539 | } | |
540 | ||
541 | } | |
542 | } | |
543 | ||
544 | val_compute_motion.bufpos = pos; | |
cde9337b JB |
545 | val_compute_motion.hpos = hpos; |
546 | val_compute_motion.vpos = vpos; | |
547 | val_compute_motion.prevhpos = prev_hpos; | |
993b6404 JB |
548 | |
549 | /* Nonzero if have just continued a line */ | |
550 | val_compute_motion.contin | |
cde9337b JB |
551 | = (pos != from |
552 | && (val_compute_motion.vpos != prev_vpos) | |
553 | && c != '\n'); | |
993b6404 JB |
554 | |
555 | return &val_compute_motion; | |
556 | } | |
993b6404 JB |
557 | |
558 | \f | |
559 | /* Return the column of position POS in window W's buffer, | |
560 | rounded down to a multiple of the internal width of W. | |
561 | This is the amount of indentation of position POS | |
562 | that is not visible in its horizontal position in the window. */ | |
563 | ||
564 | int | |
565 | pos_tab_offset (w, pos) | |
566 | struct window *w; | |
567 | register int pos; | |
568 | { | |
569 | int opoint = point; | |
570 | int col; | |
fa61c701 | 571 | int width = window_internal_width (w) - 1; |
993b6404 JB |
572 | |
573 | if (pos == BEGV || FETCH_CHAR (pos - 1) == '\n') | |
574 | return 0; | |
575 | SET_PT (pos); | |
576 | col = current_column (); | |
577 | SET_PT (opoint); | |
578 | return col - (col % width); | |
579 | } | |
580 | ||
581 | /* start_hpos is the hpos of the first character of the buffer: | |
582 | zero except for the minibuffer window, | |
583 | where it is the width of the prompt. */ | |
584 | ||
585 | struct position val_vmotion; | |
586 | ||
587 | struct position * | |
588 | vmotion (from, vtarget, width, hscroll, window) | |
589 | register int from, vtarget, width; | |
590 | int hscroll; | |
591 | Lisp_Object window; | |
592 | { | |
593 | struct position pos; | |
594 | /* vpos is cumulative vertical position, changed as from is changed */ | |
595 | register int vpos = 0; | |
596 | register int prevline; | |
597 | register int first; | |
598 | int lmargin = hscroll > 0 ? 1 - hscroll : 0; | |
599 | int selective | |
600 | = XTYPE (current_buffer->selective_display) == Lisp_Int | |
601 | ? XINT (current_buffer->selective_display) | |
56a98455 | 602 | : !NILP (current_buffer->selective_display) ? -1 : 0; |
993b6404 JB |
603 | int start_hpos = (EQ (window, minibuf_window) ? minibuf_prompt_width : 0); |
604 | ||
605 | retry: | |
606 | if (vtarget > vpos) | |
607 | { | |
608 | /* Moving downward is simple, but must calculate from beg of line | |
609 | to determine hpos of starting point */ | |
610 | if (from > BEGV && FETCH_CHAR (from - 1) != '\n') | |
611 | { | |
612 | prevline = find_next_newline (from, -1); | |
613 | while (selective > 0 | |
614 | && prevline > BEGV | |
615 | && position_indentation (prevline) >= selective) | |
616 | prevline = find_next_newline (prevline - 1, -1); | |
617 | pos = *compute_motion (prevline, 0, | |
618 | lmargin + (prevline == 1 ? start_hpos : 0), | |
cde9337b | 619 | from, 1 << (INTBITS - 2), 0, |
993b6404 JB |
620 | width, hscroll, 0); |
621 | } | |
622 | else | |
623 | { | |
624 | pos.hpos = lmargin + (from == 1 ? start_hpos : 0); | |
625 | pos.vpos = 0; | |
626 | } | |
627 | return compute_motion (from, vpos, pos.hpos, | |
cde9337b | 628 | ZV, vtarget, - (1 << (INTBITS - 2)), |
993b6404 JB |
629 | width, hscroll, pos.vpos * width); |
630 | } | |
631 | ||
632 | /* To move upward, go a line at a time until | |
633 | we have gone at least far enough */ | |
634 | ||
635 | first = 1; | |
636 | ||
637 | while ((vpos > vtarget || first) && from > BEGV) | |
638 | { | |
639 | prevline = from; | |
640 | while (1) | |
641 | { | |
642 | prevline = find_next_newline (prevline - 1, -1); | |
643 | if (prevline == BEGV | |
644 | || selective <= 0 | |
645 | || position_indentation (prevline) < selective) | |
646 | break; | |
647 | } | |
648 | pos = *compute_motion (prevline, 0, | |
649 | lmargin + (prevline == 1 ? start_hpos : 0), | |
cde9337b | 650 | from, 1 << (INTBITS - 2), 0, |
993b6404 JB |
651 | width, hscroll, 0); |
652 | vpos -= pos.vpos; | |
653 | first = 0; | |
654 | from = prevline; | |
655 | } | |
656 | ||
657 | /* If we made exactly the desired vertical distance, | |
658 | or if we hit beginning of buffer, | |
659 | return point found */ | |
660 | if (vpos >= vtarget) | |
661 | { | |
662 | val_vmotion.bufpos = from; | |
663 | val_vmotion.vpos = vpos; | |
664 | val_vmotion.hpos = lmargin; | |
665 | val_vmotion.contin = 0; | |
666 | val_vmotion.prevhpos = 0; | |
667 | return &val_vmotion; | |
668 | } | |
669 | ||
670 | /* Otherwise find the correct spot by moving down */ | |
671 | goto retry; | |
672 | } | |
673 | ||
674 | DEFUN ("vertical-motion", Fvertical_motion, Svertical_motion, 1, 1, 0, | |
675 | "Move to start of screen line LINES lines down.\n\ | |
676 | If LINES is negative, this is moving up.\n\ | |
677 | Sets point to position found; this may be start of line\n\ | |
678 | or just the start of a continuation line.\n\ | |
679 | Returns number of lines moved; may be closer to zero than LINES\n\ | |
680 | if beginning or end of buffer was reached.") | |
681 | (lines) | |
682 | Lisp_Object lines; | |
683 | { | |
684 | struct position pos; | |
685 | register struct window *w = XWINDOW (selected_window); | |
fa61c701 | 686 | int width = window_internal_width (w) - 1; |
993b6404 JB |
687 | |
688 | CHECK_NUMBER (lines, 0); | |
689 | ||
690 | pos = *vmotion (point, XINT (lines), width, | |
691 | /* Not XFASTINT since perhaps could be negative */ | |
692 | XINT (w->hscroll), selected_window); | |
693 | ||
694 | SET_PT (pos.bufpos); | |
695 | return make_number (pos.vpos); | |
696 | } | |
697 | \f | |
698 | syms_of_indent () | |
699 | { | |
700 | DEFVAR_BOOL ("indent-tabs-mode", &indent_tabs_mode, | |
701 | "*Indentation can insert tabs if this is non-nil.\n\ | |
702 | Setting this variable automatically makes it local to the current buffer."); | |
703 | indent_tabs_mode = 1; | |
704 | ||
705 | defsubr (&Scurrent_indentation); | |
706 | defsubr (&Sindent_to); | |
707 | defsubr (&Scurrent_column); | |
708 | defsubr (&Smove_to_column); | |
709 | defsubr (&Svertical_motion); | |
710 | } |