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comparison src/move.c @ 7:3fc0f57ecb91 v7.0001

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updated for version 7.0001
author vimboss
date Sun, 13 Jun 2004 20:20:40 +0000
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children 24d5189d3956
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6:c2daee826b8f 7:3fc0f57ecb91
1 /* vi:set ts=8 sts=4 sw=4:
2 *
3 * VIM - Vi IMproved by Bram Moolenaar
4 *
5 * Do ":help uganda" in Vim to read copying and usage conditions.
6 * Do ":help credits" in Vim to see a list of people who contributed.
7 * See README.txt for an overview of the Vim source code.
8 */
9 /*
10 * move.c: Functions for moving the cursor and scrolling text.
11 *
12 * There are two ways to move the cursor:
13 * 1. Move the cursor directly, the text is scrolled to keep the cursor in the
14 * window.
15 * 2. Scroll the text, the cursor is moved into the text visible in the
16 * window.
17 * The 'scrolloff' option makes this a bit complicated.
18 */
19
20 #include "vim.h"
21
22 static void comp_botline __ARGS((win_T *wp));
23 static int check_top_offset __ARGS((void));
24 static void curs_rows __ARGS((win_T *wp, int do_botline));
25 static void validate_botline_win __ARGS((win_T *wp));
26 static void validate_cheight __ARGS((void));
27
28 typedef struct
29 {
30 linenr_T lnum; /* line number */
31 #ifdef FEAT_DIFF
32 int fill; /* filler lines */
33 #endif
34 int height; /* height of added line */
35 } lineoff_T;
36
37 static void topline_back __ARGS((lineoff_T *lp));
38 static void botline_forw __ARGS((lineoff_T *lp));
39 #ifdef FEAT_DIFF
40 static void botline_topline __ARGS((lineoff_T *lp));
41 static void topline_botline __ARGS((lineoff_T *lp));
42 static void max_topfill __ARGS((void));
43 #endif
44
45 /*
46 * Compute wp->w_botline for the current wp->w_topline. Can be called after
47 * wp->w_topline changed.
48 */
49 static void
50 comp_botline(wp)
51 win_T *wp;
52 {
53 int n;
54 linenr_T lnum;
55 int done;
56 #ifdef FEAT_FOLDING
57 linenr_T last;
58 int folded;
59 #endif
60
61 /*
62 * If w_cline_row is valid, start there.
63 * Otherwise have to start at w_topline.
64 */
65 check_cursor_moved(wp);
66 if (wp->w_valid & VALID_CROW)
67 {
68 lnum = wp->w_cursor.lnum;
69 done = wp->w_cline_row;
70 }
71 else
72 {
73 lnum = wp->w_topline;
74 done = 0;
75 }
76
77 for ( ; lnum <= wp->w_buffer->b_ml.ml_line_count; ++lnum)
78 {
79 #ifdef FEAT_FOLDING
80 last = lnum;
81 folded = FALSE;
82 if (hasFoldingWin(wp, lnum, NULL, &last, TRUE, NULL))
83 {
84 n = 1;
85 folded = TRUE;
86 }
87 else
88 #endif
89 #ifdef FEAT_DIFF
90 if (lnum == wp->w_topline)
91 n = plines_win_nofill(wp, lnum, TRUE) + wp->w_topfill;
92 else
93 #endif
94 n = plines_win(wp, lnum, TRUE);
95 if (
96 #ifdef FEAT_FOLDING
97 lnum <= wp->w_cursor.lnum && last >= wp->w_cursor.lnum
98 #else
99 lnum == wp->w_cursor.lnum
100 #endif
101 )
102 {
103 wp->w_cline_row = done;
104 wp->w_cline_height = n;
105 #ifdef FEAT_FOLDING
106 wp->w_cline_folded = folded;
107 #endif
108 wp->w_valid |= (VALID_CROW|VALID_CHEIGHT);
109 }
110 if (done + n > wp->w_height)
111 break;
112 done += n;
113 #ifdef FEAT_FOLDING
114 lnum = last;
115 #endif
116 }
117
118 /* wp->w_botline is the line that is just below the window */
119 wp->w_botline = lnum;
120 wp->w_valid |= VALID_BOTLINE|VALID_BOTLINE_AP;
121
122 set_empty_rows(wp, done);
123 }
124
125 /*
126 * Update curwin->w_topline and redraw if necessary.
127 * Used to update the screen before printing a message.
128 */
129 void
130 update_topline_redraw()
131 {
132 update_topline();
133 if (must_redraw)
134 update_screen(0);
135 }
136
137 /*
138 * Update curwin->w_topline to move the cursor onto the screen.
139 */
140 void
141 update_topline()
142 {
143 long line_count;
144 int halfheight;
145 int n;
146 linenr_T old_topline;
147 #ifdef FEAT_DIFF
148 int old_topfill;
149 #endif
150 #ifdef FEAT_FOLDING
151 linenr_T lnum;
152 #endif
153 int check_topline = FALSE;
154 int check_botline = FALSE;
155 #ifdef FEAT_MOUSE
156 int save_so = p_so;
157 #endif
158
159 if (!screen_valid(TRUE))
160 return;
161
162 check_cursor_moved(curwin);
163 if (curwin->w_valid & VALID_TOPLINE)
164 return;
165
166 #ifdef FEAT_MOUSE
167 /* When dragging with the mouse, don't scroll that quickly */
168 if (mouse_dragging)
169 p_so = mouse_dragging - 1;
170 #endif
171
172 old_topline = curwin->w_topline;
173 #ifdef FEAT_DIFF
174 old_topfill = curwin->w_topfill;
175 #endif
176
177 /*
178 * If the buffer is empty, always set topline to 1.
179 */
180 if (bufempty()) /* special case - file is empty */
181 {
182 if (curwin->w_topline != 1)
183 redraw_later(NOT_VALID);
184 curwin->w_topline = 1;
185 #ifdef FEAT_DIFF
186 curwin->w_topfill = 0;
187 #endif
188 curwin->w_botline = 2;
189 curwin->w_valid |= VALID_BOTLINE|VALID_BOTLINE_AP;
190 #ifdef FEAT_SCROLLBIND
191 curwin->w_scbind_pos = 1;
192 #endif
193 }
194
195 /*
196 * If the cursor is above or near the top of the window, scroll the window
197 * to show the line the cursor is in, with 'scrolloff' context.
198 */
199 else
200 {
201 if (curwin->w_topline > 1)
202 {
203 /* If the cursor is above topline, scrolling is always needed.
204 * If the cursor is far below topline and there is no folding,
205 * scrolling down is never needed. */
206 if (curwin->w_cursor.lnum < curwin->w_topline)
207 check_topline = TRUE;
208 else if (check_top_offset())
209 check_topline = TRUE;
210 }
211 #ifdef FEAT_DIFF
212 /* Check if there are more filler lines than allowed. */
213 if (!check_topline && curwin->w_topfill > diff_check_fill(curwin,
214 curwin->w_topline))
215 check_topline = TRUE;
216 #endif
217
218 if (check_topline)
219 {
220 halfheight = curwin->w_height / 2 - 1;
221 if (halfheight < 2)
222 halfheight = 2;
223
224 #ifdef FEAT_FOLDING
225 if (hasAnyFolding(curwin))
226 {
227 /* Count the number of logical lines between the cursor and
228 * topline + p_so (approximation of how much will be
229 * scrolled). */
230 n = 0;
231 for (lnum = curwin->w_cursor.lnum;
232 lnum < curwin->w_topline + p_so; ++lnum)
233 {
234 ++n;
235 /* stop at end of file or when we know we are far off */
236 if (lnum >= curbuf->b_ml.ml_line_count || n >= halfheight)
237 break;
238 (void)hasFolding(lnum, NULL, &lnum);
239 }
240 }
241 else
242 #endif
243 n = curwin->w_topline + p_so - curwin->w_cursor.lnum;
244
245 /* If we weren't very close to begin with, we scroll to put the
246 * cursor in the middle of the window. Otherwise put the cursor
247 * near the top of the window. */
248 if (n >= halfheight)
249 scroll_cursor_halfway(FALSE);
250 else
251 {
252 scroll_cursor_top((int)p_sj, FALSE);
253 check_botline = TRUE;
254 }
255 }
256
257 else
258 {
259 #ifdef FEAT_FOLDING
260 /* Make sure topline is the first line of a fold. */
261 (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
262 #endif
263 check_botline = TRUE;
264 }
265 }
266
267 /*
268 * If the cursor is below the bottom of the window, scroll the window
269 * to put the cursor on the window.
270 * When w_botline is invalid, recompute it first, to avoid a redraw later.
271 * If w_botline was approximated, we might need a redraw later in a few
272 * cases, but we don't want to spend (a lot of) time recomputing w_botline
273 * for every small change.
274 */
275 if (check_botline)
276 {
277 if (!(curwin->w_valid & VALID_BOTLINE_AP))
278 validate_botline();
279
280 if (curwin->w_botline <= curbuf->b_ml.ml_line_count)
281 {
282 if (curwin->w_cursor.lnum < curwin->w_botline
283 && ((long)curwin->w_cursor.lnum
284 >= (long)curwin->w_botline - p_so
285 #ifdef FEAT_FOLDING
286 || hasAnyFolding(curwin)
287 #endif
288 ))
289 {
290 lineoff_T loff;
291
292 /* Cursor is above botline, check if there are 'scrolloff'
293 * window lines below the cursor. If not, need to scroll. */
294 n = curwin->w_empty_rows;
295 loff.lnum = curwin->w_cursor.lnum;
296 #ifdef FEAT_FOLDING
297 /* In a fold go to its last line. */
298 (void)hasFolding(loff.lnum, NULL, &loff.lnum);
299 #endif
300 #ifdef FEAT_DIFF
301 loff.fill = 0;
302 n += curwin->w_filler_rows;
303 #endif
304 loff.height = 0;
305 while (loff.lnum < curwin->w_botline
306 #ifdef FEAT_DIFF
307 && (loff.lnum + 1 < curwin->w_botline || loff.fill == 0)
308 #endif
309 )
310 {
311 n += loff.height;
312 if (n >= p_so)
313 break;
314 botline_forw(&loff);
315 }
316 if (n >= p_so)
317 /* sufficient context, no need to scroll */
318 check_botline = FALSE;
319 }
320 if (check_botline)
321 {
322 #ifdef FEAT_FOLDING
323 if (hasAnyFolding(curwin))
324 {
325 /* Count the number of logical lines between the cursor and
326 * botline - p_so (approximation of how much will be
327 * scrolled). */
328 line_count = 0;
329 for (lnum = curwin->w_cursor.lnum;
330 lnum >= curwin->w_botline - p_so; --lnum)
331 {
332 ++line_count;
333 /* stop at end of file or when we know we are far off */
334 if (lnum <= 0 || line_count > curwin->w_height + 1)
335 break;
336 (void)hasFolding(lnum, &lnum, NULL);
337 }
338 }
339 else
340 #endif
341 line_count = curwin->w_cursor.lnum - curwin->w_botline
342 + 1 + p_so;
343 if (line_count <= curwin->w_height + 1)
344 scroll_cursor_bot((int)p_sj, FALSE);
345 else
346 scroll_cursor_halfway(FALSE);
347 }
348 }
349 }
350 curwin->w_valid |= VALID_TOPLINE;
351
352 /*
353 * Need to redraw when topline changed.
354 */
355 if (curwin->w_topline != old_topline
356 #ifdef FEAT_DIFF
357 || curwin->w_topfill != old_topfill
358 #endif
359 )
360 {
361 dollar_vcol = 0;
362 if (curwin->w_skipcol)
363 {
364 curwin->w_skipcol = 0;
365 redraw_later(NOT_VALID);
366 }
367 else
368 redraw_later(VALID);
369 /* May need to set w_skipcol when cursor in w_topline. */
370 if (curwin->w_cursor.lnum == curwin->w_topline)
371 validate_cursor();
372 }
373
374 #ifdef FEAT_MOUSE
375 p_so = save_so;
376 #endif
377 }
378
379 /*
380 * Return TRUE when there are not 'scrolloff' lines above the cursor for the
381 * current window.
382 */
383 static int
384 check_top_offset()
385 {
386 lineoff_T loff;
387 int n;
388
389 if (curwin->w_cursor.lnum < curwin->w_topline + p_so
390 #ifdef FEAT_FOLDING
391 || hasAnyFolding(curwin)
392 #endif
393 )
394 {
395 loff.lnum = curwin->w_cursor.lnum;
396 #ifdef FEAT_DIFF
397 loff.fill = 0;
398 n = curwin->w_topfill; /* always have this context */
399 #else
400 n = 0;
401 #endif
402 /* Count the visible screen lines above the cursor line. */
403 while (n < p_so)
404 {
405 topline_back(&loff);
406 /* Stop when included a line above the window. */
407 if (loff.lnum < curwin->w_topline
408 #ifdef FEAT_DIFF
409 || (loff.lnum == curwin->w_topline && loff.fill > 0)
410 #endif
411 )
412 break;
413 n += loff.height;
414 }
415 if (n < p_so)
416 return TRUE;
417 }
418 return FALSE;
419 }
420
421 void
422 update_curswant()
423 {
424 if (curwin->w_set_curswant)
425 {
426 validate_virtcol();
427 curwin->w_curswant = curwin->w_virtcol;
428 curwin->w_set_curswant = FALSE;
429 }
430 }
431
432 /*
433 * Check if the cursor has moved. Set the w_valid flag accordingly.
434 */
435 void
436 check_cursor_moved(wp)
437 win_T *wp;
438 {
439 if (wp->w_cursor.lnum != wp->w_valid_cursor.lnum)
440 {
441 wp->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL
442 |VALID_CHEIGHT|VALID_CROW|VALID_TOPLINE);
443 wp->w_valid_cursor = wp->w_cursor;
444 wp->w_valid_leftcol = wp->w_leftcol;
445 }
446 else if (wp->w_cursor.col != wp->w_valid_cursor.col
447 || wp->w_leftcol != wp->w_valid_leftcol
448 #ifdef FEAT_VIRTUALEDIT
449 || wp->w_cursor.coladd != wp->w_valid_cursor.coladd
450 #endif
451 )
452 {
453 wp->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL);
454 wp->w_valid_cursor.col = wp->w_cursor.col;
455 wp->w_valid_leftcol = wp->w_leftcol;
456 #ifdef FEAT_VIRTUALEDIT
457 wp->w_valid_cursor.coladd = wp->w_cursor.coladd;
458 #endif
459 }
460 }
461
462 /*
463 * Call this function when some window settings have changed, which require
464 * the cursor position, botline and topline to be recomputed and the window to
465 * be redrawn. E.g, when changing the 'wrap' option or folding.
466 */
467 void
468 changed_window_setting()
469 {
470 changed_window_setting_win(curwin);
471 }
472
473 void
474 changed_window_setting_win(wp)
475 win_T *wp;
476 {
477 wp->w_lines_valid = 0;
478 changed_line_abv_curs_win(wp);
479 wp->w_valid &= ~(VALID_BOTLINE|VALID_BOTLINE_AP|VALID_TOPLINE);
480 redraw_win_later(wp, NOT_VALID);
481 }
482
483 /*
484 * Set wp->w_topline to a certain number.
485 */
486 void
487 set_topline(wp, lnum)
488 win_T *wp;
489 linenr_T lnum;
490 {
491 #ifdef FEAT_FOLDING
492 /* go to first of folded lines */
493 (void)hasFoldingWin(wp, lnum, &lnum, NULL, TRUE, NULL);
494 #endif
495 /* Approximate the value of w_botline */
496 wp->w_botline += lnum - wp->w_topline;
497 wp->w_topline = lnum;
498 #ifdef FEAT_DIFF
499 wp->w_topfill = 0;
500 #endif
501 wp->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE|VALID_TOPLINE);
502 /* Don't set VALID_TOPLINE here, 'scrolloff' needs to be checked. */
503 redraw_later(VALID);
504 }
505
506 /*
507 * Call this function when the length of the cursor line (in screen
508 * characters) has changed, and the change is before the cursor.
509 * Need to take care of w_botline separately!
510 */
511 void
512 changed_cline_bef_curs()
513 {
514 curwin->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL
515 |VALID_CHEIGHT|VALID_TOPLINE);
516 }
517
518 void
519 changed_cline_bef_curs_win(wp)
520 win_T *wp;
521 {
522 wp->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL
523 |VALID_CHEIGHT|VALID_TOPLINE);
524 }
525
526 #if 0 /* not used */
527 /*
528 * Call this function when the length of the cursor line (in screen
529 * characters) has changed, and the position of the cursor doesn't change.
530 * Need to take care of w_botline separately!
531 */
532 void
533 changed_cline_aft_curs()
534 {
535 curwin->w_valid &= ~VALID_CHEIGHT;
536 }
537 #endif
538
539 /*
540 * Call this function when the length of a line (in screen characters) above
541 * the cursor have changed.
542 * Need to take care of w_botline separately!
543 */
544 void
545 changed_line_abv_curs()
546 {
547 curwin->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL|VALID_CROW
548 |VALID_CHEIGHT|VALID_TOPLINE);
549 }
550
551 void
552 changed_line_abv_curs_win(wp)
553 win_T *wp;
554 {
555 wp->w_valid &= ~(VALID_WROW|VALID_WCOL|VALID_VIRTCOL|VALID_CROW
556 |VALID_CHEIGHT|VALID_TOPLINE);
557 }
558
559 /*
560 * Make sure the value of curwin->w_botline is valid.
561 */
562 void
563 validate_botline()
564 {
565 if (!(curwin->w_valid & VALID_BOTLINE))
566 comp_botline(curwin);
567 }
568
569 /*
570 * Make sure the value of wp->w_botline is valid.
571 */
572 static void
573 validate_botline_win(wp)
574 win_T *wp;
575 {
576 if (!(wp->w_valid & VALID_BOTLINE))
577 comp_botline(wp);
578 }
579
580 /*
581 * Mark curwin->w_botline as invalid (because of some change in the buffer).
582 */
583 void
584 invalidate_botline()
585 {
586 curwin->w_valid &= ~(VALID_BOTLINE|VALID_BOTLINE_AP);
587 }
588
589 void
590 invalidate_botline_win(wp)
591 win_T *wp;
592 {
593 wp->w_valid &= ~(VALID_BOTLINE|VALID_BOTLINE_AP);
594 }
595
596 #if 0 /* never used */
597 /*
598 * Mark curwin->w_botline as approximated (because of some small change in the
599 * buffer).
600 */
601 void
602 approximate_botline()
603 {
604 curwin->w_valid &= ~VALID_BOTLINE;
605 }
606 #endif
607
608 void
609 approximate_botline_win(wp)
610 win_T *wp;
611 {
612 wp->w_valid &= ~VALID_BOTLINE;
613 }
614
615 #if 0 /* not used */
616 /*
617 * Return TRUE if curwin->w_botline is valid.
618 */
619 int
620 botline_valid()
621 {
622 return (curwin->w_valid & VALID_BOTLINE);
623 }
624 #endif
625
626 #if 0 /* not used */
627 /*
628 * Return TRUE if curwin->w_botline is valid or approximated.
629 */
630 int
631 botline_approximated()
632 {
633 return (curwin->w_valid & VALID_BOTLINE_AP);
634 }
635 #endif
636
637 /*
638 * Return TRUE if curwin->w_wrow and curwin->w_wcol are valid.
639 */
640 int
641 cursor_valid()
642 {
643 check_cursor_moved(curwin);
644 return ((curwin->w_valid & (VALID_WROW|VALID_WCOL)) ==
645 (VALID_WROW|VALID_WCOL));
646 }
647
648 /*
649 * Validate cursor position. Makes sure w_wrow and w_wcol are valid.
650 * w_topline must be valid, you may need to call update_topline() first!
651 */
652 void
653 validate_cursor()
654 {
655 check_cursor_moved(curwin);
656 if ((curwin->w_valid & (VALID_WCOL|VALID_WROW)) != (VALID_WCOL|VALID_WROW))
657 curs_columns(TRUE);
658 }
659
660 #if defined(FEAT_GUI) || defined(PROTO)
661 /*
662 * validate w_cline_row.
663 */
664 void
665 validate_cline_row()
666 {
667 /*
668 * First make sure that w_topline is valid (after moving the cursor).
669 */
670 update_topline();
671 check_cursor_moved(curwin);
672 if (!(curwin->w_valid & VALID_CROW))
673 curs_rows(curwin, FALSE);
674 }
675 #endif
676
677 /*
678 * Compute wp->w_cline_row and wp->w_cline_height, based on the current value
679 * of wp->w_topine.
680 *
681 * Returns OK when cursor is in the window, FAIL when it isn't.
682 */
683 static void
684 curs_rows(wp, do_botline)
685 win_T *wp;
686 int do_botline; /* also compute w_botline */
687 {
688 linenr_T lnum;
689 int i;
690 int all_invalid;
691 int valid;
692 #ifdef FEAT_FOLDING
693 long fold_count;
694 #endif
695
696 /* Check if wp->w_lines[].wl_size is invalid */
697 all_invalid = (!redrawing()
698 || wp->w_lines_valid == 0
699 || wp->w_lines[0].wl_lnum > wp->w_topline);
700 i = 0;
701 wp->w_cline_row = 0;
702 for (lnum = wp->w_topline; lnum < wp->w_cursor.lnum; ++i)
703 {
704 valid = FALSE;
705 if (!all_invalid && i < wp->w_lines_valid)
706 {
707 if (wp->w_lines[i].wl_lnum < lnum || !wp->w_lines[i].wl_valid)
708 continue; /* skip changed or deleted lines */
709 if (wp->w_lines[i].wl_lnum == lnum)
710 {
711 #ifdef FEAT_FOLDING
712 /* Check for newly inserted lines below this row, in which
713 * case we need to check for folded lines. */
714 if (!wp->w_buffer->b_mod_set
715 || wp->w_lines[i].wl_lastlnum < wp->w_cursor.lnum
716 || wp->w_buffer->b_mod_top
717 > wp->w_lines[i].wl_lastlnum + 1)
718 #endif
719 valid = TRUE;
720 }
721 else if (wp->w_lines[i].wl_lnum > lnum)
722 --i; /* hold at inserted lines */
723 }
724 if (valid
725 #ifdef FEAT_DIFF
726 && (lnum != wp->w_topline || !wp->w_p_diff)
727 #endif
728 )
729 {
730 #ifdef FEAT_FOLDING
731 lnum = wp->w_lines[i].wl_lastlnum + 1;
732 /* Cursor inside folded lines, don't count this row */
733 if (lnum > wp->w_cursor.lnum)
734 break;
735 #else
736 ++lnum;
737 #endif
738 wp->w_cline_row += wp->w_lines[i].wl_size;
739 }
740 else
741 {
742 #ifdef FEAT_FOLDING
743 fold_count = foldedCount(wp, lnum, NULL);
744 if (fold_count)
745 {
746 lnum += fold_count;
747 if (lnum > wp->w_cursor.lnum)
748 break;
749 ++wp->w_cline_row;
750 }
751 else
752 #endif
753 #ifdef FEAT_DIFF
754 if (lnum == wp->w_topline)
755 wp->w_cline_row += plines_win_nofill(wp, lnum++, TRUE)
756 + wp->w_topfill;
757 else
758 #endif
759 wp->w_cline_row += plines_win(wp, lnum++, TRUE);
760 }
761 }
762
763 check_cursor_moved(wp);
764 if (!(wp->w_valid & VALID_CHEIGHT))
765 {
766 if (all_invalid
767 || i == wp->w_lines_valid
768 || (i < wp->w_lines_valid
769 && (!wp->w_lines[i].wl_valid
770 || wp->w_lines[i].wl_lnum != wp->w_cursor.lnum)))
771 {
772 #ifdef FEAT_DIFF
773 if (wp->w_cursor.lnum == wp->w_topline)
774 wp->w_cline_height = plines_win_nofill(wp, wp->w_cursor.lnum,
775 TRUE) + wp->w_topfill;
776 else
777 #endif
778 wp->w_cline_height = plines_win(wp, wp->w_cursor.lnum, TRUE);
779 #ifdef FEAT_FOLDING
780 wp->w_cline_folded = hasFoldingWin(wp, wp->w_cursor.lnum,
781 NULL, NULL, TRUE, NULL);
782 #endif
783 }
784 else if (i > wp->w_lines_valid)
785 {
786 /* a line that is too long to fit on the last screen line */
787 wp->w_cline_height = 0;
788 #ifdef FEAT_FOLDING
789 wp->w_cline_folded = hasFoldingWin(wp, wp->w_cursor.lnum,
790 NULL, NULL, TRUE, NULL);
791 #endif
792 }
793 else
794 {
795 wp->w_cline_height = wp->w_lines[i].wl_size;
796 #ifdef FEAT_FOLDING
797 wp->w_cline_folded = wp->w_lines[i].wl_folded;
798 #endif
799 }
800 }
801
802 wp->w_valid |= VALID_CROW|VALID_CHEIGHT;
803
804 /* validate botline too, if update_screen doesn't do it */
805 if (do_botline && all_invalid)
806 validate_botline_win(wp);
807 }
808
809 /*
810 * Validate curwin->w_virtcol only.
811 */
812 void
813 validate_virtcol()
814 {
815 validate_virtcol_win(curwin);
816 }
817
818 /*
819 * Validate wp->w_virtcol only.
820 */
821 void
822 validate_virtcol_win(wp)
823 win_T *wp;
824 {
825 check_cursor_moved(wp);
826 if (!(wp->w_valid & VALID_VIRTCOL))
827 {
828 getvvcol(wp, &wp->w_cursor, NULL, &(wp->w_virtcol), NULL);
829 wp->w_valid |= VALID_VIRTCOL;
830 }
831 }
832
833 /*
834 * Validate curwin->w_cline_height only.
835 */
836 static void
837 validate_cheight()
838 {
839 check_cursor_moved(curwin);
840 if (!(curwin->w_valid & VALID_CHEIGHT))
841 {
842 #ifdef FEAT_DIFF
843 if (curwin->w_cursor.lnum == curwin->w_topline)
844 curwin->w_cline_height = plines_nofill(curwin->w_cursor.lnum)
845 + curwin->w_topfill;
846 else
847 #endif
848 curwin->w_cline_height = plines(curwin->w_cursor.lnum);
849 #ifdef FEAT_FOLDING
850 curwin->w_cline_folded = hasFolding(curwin->w_cursor.lnum, NULL, NULL);
851 #endif
852 curwin->w_valid |= VALID_CHEIGHT;
853 }
854 }
855
856 /*
857 * validate w_wcol and w_virtcol only. Only correct when 'wrap' on!
858 */
859 void
860 validate_cursor_col()
861 {
862 colnr_T off;
863 colnr_T col;
864
865 validate_virtcol();
866 if (!(curwin->w_valid & VALID_WCOL))
867 {
868 col = curwin->w_virtcol;
869 off = curwin_col_off();
870 col += off;
871
872 /* long line wrapping, adjust curwin->w_wrow */
873 if (curwin->w_p_wrap && col >= (colnr_T)W_WIDTH(curwin)
874 #ifdef FEAT_VERTSPLIT
875 && curwin->w_width != 0
876 #endif
877 )
878 {
879 col -= W_WIDTH(curwin);
880 col = col % (W_WIDTH(curwin) - off + curwin_col_off2());
881 }
882 curwin->w_wcol = col;
883 curwin->w_valid |= VALID_WCOL;
884 }
885 }
886
887 /*
888 * Compute offset of a window, occupied by line number, fold column and sign
889 * column (these don't move when scrolling horizontally).
890 */
891 int
892 win_col_off(wp)
893 win_T *wp;
894 {
895 return ((wp->w_p_nu ? 8 : 0)
896 #ifdef FEAT_CMDWIN
897 + (cmdwin_type == 0 || wp != curwin ? 0 : 1)
898 #endif
899 #ifdef FEAT_FOLDING
900 + wp->w_p_fdc
901 #endif
902 #ifdef FEAT_SIGNS
903 + (
904 # ifdef FEAT_NETBEANS_INTG
905 /* always show glyph gutter in netbeans */
906 usingNetbeans ||
907 # endif
908 wp->w_buffer->b_signlist != NULL ? 2 : 0)
909 #endif
910 );
911 }
912
913 int
914 curwin_col_off()
915 {
916 return win_col_off(curwin);
917 }
918
919 /*
920 * Return the difference in column offset for the second screen line of a
921 * wrapped line. It's 8 if 'number' is on and 'n' is in 'cpoptions'.
922 */
923 int
924 win_col_off2(wp)
925 win_T *wp;
926 {
927 if (wp->w_p_nu && vim_strchr(p_cpo, CPO_NUMCOL) != NULL)
928 return 8;
929 return 0;
930 }
931
932 int
933 curwin_col_off2()
934 {
935 return win_col_off2(curwin);
936 }
937
938 /*
939 * compute curwin->w_wcol and curwin->w_virtcol.
940 * Also updates curwin->w_wrow and curwin->w_cline_row.
941 * Also updates curwin->w_leftcol.
942 */
943 void
944 curs_columns(scroll)
945 int scroll; /* when TRUE, may scroll horizontally */
946 {
947 int diff;
948 int extra; /* offset for first screen line */
949 int off_left, off_right;
950 int n;
951 int p_lines;
952 int width = 0;
953 int textwidth;
954 int new_leftcol;
955 colnr_T startcol;
956 colnr_T endcol;
957 colnr_T prev_skipcol;
958
959 /*
960 * First make sure that w_topline is valid (after moving the cursor).
961 */
962 update_topline();
963
964 /*
965 * Next make sure that w_cline_row is valid.
966 */
967 if (!(curwin->w_valid & VALID_CROW))
968 curs_rows(curwin, FALSE);
969
970 /*
971 * Compute the number of virtual columns.
972 */
973 #ifdef FEAT_FOLDING
974 if (curwin->w_cline_folded)
975 /* In a folded line the cursor is always in the first column */
976 startcol = curwin->w_virtcol = endcol = curwin->w_leftcol;
977 else
978 #endif
979 getvvcol(curwin, &curwin->w_cursor,
980 &startcol, &(curwin->w_virtcol), &endcol);
981
982 /* remove '$' from change command when cursor moves onto it */
983 if (startcol > dollar_vcol)
984 dollar_vcol = 0;
985
986 extra = curwin_col_off();
987 curwin->w_wcol = curwin->w_virtcol + extra;
988 endcol += extra;
989
990 /*
991 * Now compute w_wrow, counting screen lines from w_cline_row.
992 */
993 curwin->w_wrow = curwin->w_cline_row;
994
995 textwidth = W_WIDTH(curwin) - extra;
996 if (textwidth <= 0)
997 {
998 /* No room for text, put cursor in last char of window. */
999 curwin->w_wcol = W_WIDTH(curwin) - 1;
1000 curwin->w_wrow = curwin->w_height - 1;
1001 }
1002 else if (curwin->w_p_wrap
1003 #ifdef FEAT_VERTSPLIT
1004 && curwin->w_width != 0
1005 #endif
1006 )
1007 {
1008 width = textwidth + curwin_col_off2();
1009
1010 /* long line wrapping, adjust curwin->w_wrow */
1011 if (curwin->w_wcol >= W_WIDTH(curwin))
1012 {
1013 n = (curwin->w_wcol - W_WIDTH(curwin)) / width + 1;
1014 curwin->w_wcol -= n * width;
1015 curwin->w_wrow += n;
1016
1017 #ifdef FEAT_LINEBREAK
1018 /* When cursor wraps to first char of next line in Insert
1019 * mode, the 'showbreak' string isn't shown, backup to first
1020 * column */
1021 if (*p_sbr && *ml_get_cursor() == NUL
1022 && curwin->w_wcol == (int)vim_strsize(p_sbr))
1023 curwin->w_wcol = 0;
1024 #endif
1025 }
1026 }
1027
1028 /* No line wrapping: compute curwin->w_leftcol if scrolling is on and line
1029 * is not folded.
1030 * If scrolling is off, curwin->w_leftcol is assumed to be 0 */
1031 else if (scroll
1032 #ifdef FEAT_FOLDING
1033 && !curwin->w_cline_folded
1034 #endif
1035 )
1036 {
1037 /*
1038 * If Cursor is left of the screen, scroll rightwards.
1039 * If Cursor is right of the screen, scroll leftwards
1040 * If we get closer to the edge than 'sidescrolloff', scroll a little
1041 * extra
1042 */
1043 off_left = (int)startcol - (int)curwin->w_leftcol - p_siso;
1044 off_right = (int)endcol - (int)(curwin->w_leftcol + W_WIDTH(curwin)
1045 - p_siso) + 1;
1046 if (off_left < 0 || off_right > 0)
1047 {
1048 if (off_left < 0)
1049 diff = -off_left;
1050 else
1051 diff = off_right;
1052
1053 /* When far off or not enough room on either side, put cursor in
1054 * middle of window. */
1055 if (p_ss == 0 || diff >= textwidth / 2 || off_right >= off_left)
1056 new_leftcol = curwin->w_wcol - extra - textwidth / 2;
1057 else
1058 {
1059 if (diff < p_ss)
1060 diff = p_ss;
1061 if (off_left < 0)
1062 new_leftcol = curwin->w_leftcol - diff;
1063 else
1064 new_leftcol = curwin->w_leftcol + diff;
1065 }
1066 if (new_leftcol < 0)
1067 new_leftcol = 0;
1068 if (new_leftcol != (int)curwin->w_leftcol)
1069 {
1070 curwin->w_leftcol = new_leftcol;
1071 /* screen has to be redrawn with new curwin->w_leftcol */
1072 redraw_later(NOT_VALID);
1073 }
1074 }
1075 curwin->w_wcol -= curwin->w_leftcol;
1076 }
1077 else if (curwin->w_wcol > (int)curwin->w_leftcol)
1078 curwin->w_wcol -= curwin->w_leftcol;
1079 else
1080 curwin->w_wcol = 0;
1081
1082 #ifdef FEAT_DIFF
1083 /* Skip over filler lines. At the top use w_topfill, there
1084 * may be some filler lines above the window. */
1085 if (curwin->w_cursor.lnum == curwin->w_topline)
1086 curwin->w_wrow += curwin->w_topfill;
1087 else
1088 curwin->w_wrow += diff_check_fill(curwin, curwin->w_cursor.lnum);
1089 #endif
1090
1091 prev_skipcol = curwin->w_skipcol;
1092
1093 p_lines = 0;
1094 if ((curwin->w_wrow >= curwin->w_height
1095 || ((prev_skipcol > 0
1096 || curwin->w_wrow + p_so >= curwin->w_height)
1097 && (p_lines =
1098 #ifdef FEAT_DIFF
1099 plines_win_nofill
1100 #else
1101 plines_win
1102 #endif
1103 (curwin, curwin->w_cursor.lnum, FALSE))
1104 - 1 >= curwin->w_height))
1105 && curwin->w_height != 0
1106 && curwin->w_cursor.lnum == curwin->w_topline
1107 && width > 0
1108 #ifdef FEAT_VERTSPLIT
1109 && curwin->w_width != 0
1110 #endif
1111 )
1112 {
1113 /* Cursor past end of screen. Happens with a single line that does
1114 * not fit on screen. Find a skipcol to show the text around the
1115 * cursor. Avoid scrolling all the time. compute value of "extra":
1116 * 1: Less than "p_so" lines above
1117 * 2: Less than "p_so" lines below
1118 * 3: both of them */
1119 extra = 0;
1120 if (curwin->w_skipcol + p_so * width > curwin->w_virtcol)
1121 extra = 1;
1122 /* Compute last display line of the buffer line that we want at the
1123 * bottom of the window. */
1124 if (p_lines == 0)
1125 p_lines = plines_win(curwin, curwin->w_cursor.lnum, FALSE);
1126 --p_lines;
1127 if (p_lines > curwin->w_wrow + p_so)
1128 n = curwin->w_wrow + p_so;
1129 else
1130 n = p_lines;
1131 if ((colnr_T)n >= curwin->w_height + curwin->w_skipcol / width)
1132 extra += 2;
1133
1134 if (extra == 3 || p_lines < p_so * 2)
1135 {
1136 /* not enough room for 'scrolloff', put cursor in the middle */
1137 n = curwin->w_virtcol / width;
1138 if (n > curwin->w_height / 2)
1139 n -= curwin->w_height / 2;
1140 else
1141 n = 0;
1142 /* don't skip more than necessary */
1143 if (n > p_lines - curwin->w_height + 1)
1144 n = p_lines - curwin->w_height + 1;
1145 curwin->w_skipcol = n * width;
1146 }
1147 else if (extra == 1)
1148 {
1149 /* less then 'scrolloff' lines above, decrease skipcol */
1150 extra = (curwin->w_skipcol + p_so * width - curwin->w_virtcol
1151 + width - 1) / width;
1152 if (extra > 0)
1153 {
1154 if ((colnr_T)(extra * width) > curwin->w_skipcol)
1155 extra = curwin->w_skipcol / width;
1156 curwin->w_skipcol -= extra * width;
1157 }
1158 }
1159 else if (extra == 2)
1160 {
1161 /* less then 'scrolloff' lines below, increase skipcol */
1162 endcol = (n - curwin->w_height + 1) * width;
1163 while (endcol > curwin->w_virtcol)
1164 endcol -= width;
1165 if (endcol > curwin->w_skipcol)
1166 curwin->w_skipcol = endcol;
1167 }
1168
1169 curwin->w_wrow -= curwin->w_skipcol / width;
1170 if (curwin->w_wrow >= curwin->w_height)
1171 {
1172 /* small window, make sure cursor is in it */
1173 extra = curwin->w_wrow - curwin->w_height + 1;
1174 curwin->w_skipcol += extra * width;
1175 curwin->w_wrow -= extra;
1176 }
1177
1178 extra = ((int)prev_skipcol - (int)curwin->w_skipcol) / width;
1179 if (extra > 0)
1180 win_ins_lines(curwin, 0, extra, FALSE, FALSE);
1181 else if (extra < 0)
1182 win_del_lines(curwin, 0, -extra, FALSE, FALSE);
1183 }
1184 else
1185 curwin->w_skipcol = 0;
1186 if (prev_skipcol != curwin->w_skipcol)
1187 redraw_later(NOT_VALID);
1188
1189 curwin->w_valid |= VALID_WCOL|VALID_WROW|VALID_VIRTCOL;
1190 }
1191
1192 /*
1193 * Scroll the current window down by "line_count" logical lines. "CTRL-Y"
1194 */
1195 /*ARGSUSED*/
1196 void
1197 scrolldown(line_count, byfold)
1198 long line_count;
1199 int byfold; /* TRUE: count a closed fold as one line */
1200 {
1201 long done = 0; /* total # of physical lines done */
1202 int wrow;
1203 int moved = FALSE;
1204
1205 #ifdef FEAT_FOLDING
1206 linenr_T first;
1207
1208 /* Make sure w_topline is at the first of a sequence of folded lines. */
1209 (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
1210 #endif
1211 validate_cursor(); /* w_wrow needs to be valid */
1212 while (line_count-- > 0)
1213 {
1214 #ifdef FEAT_DIFF
1215 if (curwin->w_topfill < diff_check(curwin, curwin->w_topline))
1216 {
1217 ++curwin->w_topfill;
1218 ++done;
1219 }
1220 else
1221 #endif
1222 {
1223 if (curwin->w_topline == 1)
1224 break;
1225 --curwin->w_topline;
1226 #ifdef FEAT_DIFF
1227 curwin->w_topfill = 0;
1228 #endif
1229 #ifdef FEAT_FOLDING
1230 /* A sequence of folded lines only counts for one logical line */
1231 if (hasFolding(curwin->w_topline, &first, NULL))
1232 {
1233 ++done;
1234 if (!byfold)
1235 line_count -= curwin->w_topline - first - 1;
1236 curwin->w_botline -= curwin->w_topline - first;
1237 curwin->w_topline = first;
1238 }
1239 else
1240 #endif
1241 #ifdef FEAT_DIFF
1242 done += plines_nofill(curwin->w_topline);
1243 #else
1244 done += plines(curwin->w_topline);
1245 #endif
1246 }
1247 --curwin->w_botline; /* approximate w_botline */
1248 invalidate_botline();
1249 }
1250 curwin->w_wrow += done; /* keep w_wrow updated */
1251 curwin->w_cline_row += done; /* keep w_cline_row updated */
1252
1253 #ifdef FEAT_DIFF
1254 if (curwin->w_cursor.lnum == curwin->w_topline)
1255 curwin->w_cline_row = 0;
1256 check_topfill(curwin, TRUE);
1257 #endif
1258
1259 /*
1260 * Compute the row number of the last row of the cursor line
1261 * and move the cursor onto the displayed part of the window.
1262 */
1263 wrow = curwin->w_wrow;
1264 if (curwin->w_p_wrap
1265 #ifdef FEAT_VERTSPLIT
1266 && curwin->w_width != 0
1267 #endif
1268 )
1269 {
1270 validate_virtcol();
1271 validate_cheight();
1272 wrow += curwin->w_cline_height - 1 -
1273 curwin->w_virtcol / W_WIDTH(curwin);
1274 }
1275 while (wrow >= curwin->w_height && curwin->w_cursor.lnum > 1)
1276 {
1277 #ifdef FEAT_FOLDING
1278 if (hasFolding(curwin->w_cursor.lnum, &first, NULL))
1279 {
1280 --wrow;
1281 if (first == 1)
1282 curwin->w_cursor.lnum = 1;
1283 else
1284 curwin->w_cursor.lnum = first - 1;
1285 }
1286 else
1287 #endif
1288 wrow -= plines(curwin->w_cursor.lnum--);
1289 curwin->w_valid &=
1290 ~(VALID_WROW|VALID_WCOL|VALID_CHEIGHT|VALID_CROW|VALID_VIRTCOL);
1291 moved = TRUE;
1292 }
1293 if (moved)
1294 {
1295 #ifdef FEAT_FOLDING
1296 /* Move cursor to first line of closed fold. */
1297 foldAdjustCursor();
1298 #endif
1299 coladvance(curwin->w_curswant);
1300 }
1301 }
1302
1303 /*
1304 * Scroll the current window up by "line_count" logical lines. "CTRL-E"
1305 */
1306 /*ARGSUSED*/
1307 void
1308 scrollup(line_count, byfold)
1309 long line_count;
1310 int byfold; /* TRUE: count a closed fold as one line */
1311 {
1312 #if defined(FEAT_FOLDING) || defined(FEAT_DIFF)
1313 linenr_T lnum;
1314
1315 if (
1316 # ifdef FEAT_FOLDING
1317 (byfold && hasAnyFolding(curwin))
1318 # ifdef FEAT_DIFF
1319 ||
1320 # endif
1321 # endif
1322 # ifdef FEAT_DIFF
1323 curwin->w_p_diff
1324 # endif
1325 )
1326 {
1327 /* count each sequence of folded lines as one logical line */
1328 lnum = curwin->w_topline;
1329 while (line_count--)
1330 {
1331 # ifdef FEAT_DIFF
1332 if (curwin->w_topfill > 0)
1333 --curwin->w_topfill;
1334 else
1335 # endif
1336 {
1337 # ifdef FEAT_FOLDING
1338 if (byfold)
1339 (void)hasFolding(lnum, NULL, &lnum);
1340 # endif
1341 if (lnum >= curbuf->b_ml.ml_line_count)
1342 break;
1343 ++lnum;
1344 # ifdef FEAT_DIFF
1345 curwin->w_topfill = diff_check_fill(curwin, lnum);
1346 # endif
1347 }
1348 }
1349 /* approximate w_botline */
1350 curwin->w_botline += lnum - curwin->w_topline;
1351 curwin->w_topline = lnum;
1352 }
1353 else
1354 #endif
1355 {
1356 curwin->w_topline += line_count;
1357 curwin->w_botline += line_count; /* approximate w_botline */
1358 }
1359
1360 if (curwin->w_topline > curbuf->b_ml.ml_line_count)
1361 curwin->w_topline = curbuf->b_ml.ml_line_count;
1362 if (curwin->w_botline > curbuf->b_ml.ml_line_count + 1)
1363 curwin->w_botline = curbuf->b_ml.ml_line_count + 1;
1364
1365 #ifdef FEAT_DIFF
1366 check_topfill(curwin, FALSE);
1367 #endif
1368
1369 #ifdef FEAT_FOLDING
1370 if (hasAnyFolding(curwin))
1371 /* Make sure w_topline is at the first of a sequence of folded lines. */
1372 (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
1373 #endif
1374
1375 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE);
1376 if (curwin->w_cursor.lnum < curwin->w_topline)
1377 {
1378 curwin->w_cursor.lnum = curwin->w_topline;
1379 curwin->w_valid &=
1380 ~(VALID_WROW|VALID_WCOL|VALID_CHEIGHT|VALID_CROW|VALID_VIRTCOL);
1381 coladvance(curwin->w_curswant);
1382 }
1383 }
1384
1385 #ifdef FEAT_DIFF
1386 /*
1387 * Don't end up with too many filler lines in the window.
1388 */
1389 void
1390 check_topfill(wp, down)
1391 win_T *wp;
1392 int down; /* when TRUE scroll down when not enough space */
1393 {
1394 int n;
1395
1396 if (wp->w_topfill > 0)
1397 {
1398 n = plines_win_nofill(wp, wp->w_topline, TRUE);
1399 if (wp->w_topfill + n > wp->w_height)
1400 {
1401 if (down && wp->w_topline > 1)
1402 {
1403 --wp->w_topline;
1404 wp->w_topfill = 0;
1405 }
1406 else
1407 {
1408 wp->w_topfill = wp->w_height - n;
1409 if (wp->w_topfill < 0)
1410 wp->w_topfill = 0;
1411 }
1412 }
1413 }
1414 }
1415
1416 /*
1417 * Use as many filler lines as possible for w_topline. Make sure w_topline
1418 * is still visible.
1419 */
1420 static void
1421 max_topfill()
1422 {
1423 int n;
1424
1425 n = plines_nofill(curwin->w_topline);
1426 if (n >= curwin->w_height)
1427 curwin->w_topfill = 0;
1428 else
1429 {
1430 curwin->w_topfill = diff_check_fill(curwin, curwin->w_topline);
1431 if (curwin->w_topfill + n > curwin->w_height)
1432 curwin->w_topfill = curwin->w_height - n;
1433 }
1434 }
1435 #endif
1436
1437 #if defined(FEAT_INS_EXPAND) || defined(PROTO)
1438 /*
1439 * Scroll the screen one line down, but don't do it if it would move the
1440 * cursor off the screen.
1441 */
1442 void
1443 scrolldown_clamp()
1444 {
1445 int end_row;
1446 #ifdef FEAT_DIFF
1447 int can_fill = (curwin->w_topfill
1448 < diff_check_fill(curwin, curwin->w_topline));
1449 #endif
1450
1451 if (curwin->w_topline <= 1
1452 #ifdef FEAT_DIFF
1453 && !can_fill
1454 #endif
1455 )
1456 return;
1457
1458 validate_cursor(); /* w_wrow needs to be valid */
1459
1460 /*
1461 * Compute the row number of the last row of the cursor line
1462 * and make sure it doesn't go off the screen. Make sure the cursor
1463 * doesn't go past 'scrolloff' lines from the screen end.
1464 */
1465 end_row = curwin->w_wrow;
1466 #ifdef FEAT_DIFF
1467 if (can_fill)
1468 ++end_row;
1469 else
1470 end_row += plines_nofill(curwin->w_topline - 1);
1471 #else
1472 end_row += plines(curwin->w_topline - 1);
1473 #endif
1474 if (curwin->w_p_wrap
1475 #ifdef FEAT_VERTSPLIT
1476 && curwin->w_width != 0
1477 #endif
1478 )
1479 {
1480 validate_cheight();
1481 validate_virtcol();
1482 end_row += curwin->w_cline_height - 1 -
1483 curwin->w_virtcol / W_WIDTH(curwin);
1484 }
1485 if (end_row < curwin->w_height - p_so)
1486 {
1487 #ifdef FEAT_DIFF
1488 if (can_fill)
1489 {
1490 ++curwin->w_topfill;
1491 check_topfill(curwin, TRUE);
1492 }
1493 else
1494 {
1495 --curwin->w_topline;
1496 curwin->w_topfill = 0;
1497 }
1498 #else
1499 --curwin->w_topline;
1500 #endif
1501 #ifdef FEAT_FOLDING
1502 hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
1503 #endif
1504 --curwin->w_botline; /* approximate w_botline */
1505 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE);
1506 }
1507 }
1508
1509 /*
1510 * Scroll the screen one line up, but don't do it if it would move the cursor
1511 * off the screen.
1512 */
1513 void
1514 scrollup_clamp()
1515 {
1516 int start_row;
1517
1518 if (curwin->w_topline == curbuf->b_ml.ml_line_count
1519 #ifdef FEAT_DIFF
1520 && curwin->w_topfill == 0
1521 #endif
1522 )
1523 return;
1524
1525 validate_cursor(); /* w_wrow needs to be valid */
1526
1527 /*
1528 * Compute the row number of the first row of the cursor line
1529 * and make sure it doesn't go off the screen. Make sure the cursor
1530 * doesn't go before 'scrolloff' lines from the screen start.
1531 */
1532 #ifdef FEAT_DIFF
1533 start_row = curwin->w_wrow - plines_nofill(curwin->w_topline)
1534 - curwin->w_topfill;
1535 #else
1536 start_row = curwin->w_wrow - plines(curwin->w_topline);
1537 #endif
1538 if (curwin->w_p_wrap
1539 #ifdef FEAT_VERTSPLIT
1540 && curwin->w_width != 0
1541 #endif
1542 )
1543 {
1544 validate_virtcol();
1545 start_row -= curwin->w_virtcol / W_WIDTH(curwin);
1546 }
1547 if (start_row >= p_so)
1548 {
1549 #ifdef FEAT_DIFF
1550 if (curwin->w_topfill > 0)
1551 --curwin->w_topfill;
1552 else
1553 #endif
1554 ++curwin->w_topline;
1555 ++curwin->w_botline; /* approximate w_botline */
1556 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE);
1557 }
1558 }
1559 #endif /* FEAT_INS_EXPAND */
1560
1561 /*
1562 * Add one line above "lp->lnum". This can be a filler line, a closed fold or
1563 * a (wrapped) text line. Uses and sets "lp->fill".
1564 * Returns the height of the added line in "lp->height".
1565 * Lines above the first one are incredibly high.
1566 */
1567 static void
1568 topline_back(lp)
1569 lineoff_T *lp;
1570 {
1571 #ifdef FEAT_DIFF
1572 if (lp->fill < diff_check_fill(curwin, lp->lnum))
1573 {
1574 /* Add a filler line. */
1575 ++lp->fill;
1576 lp->height = 1;
1577 }
1578 else
1579 #endif
1580 {
1581 --lp->lnum;
1582 #ifdef FEAT_DIFF
1583 lp->fill = 0;
1584 #endif
1585 if (lp->lnum < 1)
1586 lp->height = MAXCOL;
1587 else
1588 #ifdef FEAT_FOLDING
1589 if (hasFolding(lp->lnum, &lp->lnum, NULL))
1590 /* Add a closed fold */
1591 lp->height = 1;
1592 else
1593 #endif
1594 {
1595 #ifdef FEAT_DIFF
1596 lp->height = plines_nofill(lp->lnum);
1597 #else
1598 lp->height = plines(lp->lnum);
1599 #endif
1600 }
1601 }
1602 }
1603
1604 /*
1605 * Add one line below "lp->lnum". This can be a filler line, a closed fold or
1606 * a (wrapped) text line. Uses and sets "lp->fill".
1607 * Returns the height of the added line in "lp->height".
1608 * Lines below the last one are incredibly high.
1609 */
1610 static void
1611 botline_forw(lp)
1612 lineoff_T *lp;
1613 {
1614 #ifdef FEAT_DIFF
1615 if (lp->fill < diff_check_fill(curwin, lp->lnum + 1))
1616 {
1617 /* Add a filler line. */
1618 ++lp->fill;
1619 lp->height = 1;
1620 }
1621 else
1622 #endif
1623 {
1624 ++lp->lnum;
1625 #ifdef FEAT_DIFF
1626 lp->fill = 0;
1627 #endif
1628 if (lp->lnum > curbuf->b_ml.ml_line_count)
1629 lp->height = MAXCOL;
1630 else
1631 #ifdef FEAT_FOLDING
1632 if (hasFolding(lp->lnum, NULL, &lp->lnum))
1633 /* Add a closed fold */
1634 lp->height = 1;
1635 else
1636 #endif
1637 {
1638 #ifdef FEAT_DIFF
1639 lp->height = plines_nofill(lp->lnum);
1640 #else
1641 lp->height = plines(lp->lnum);
1642 #endif
1643 }
1644 }
1645 }
1646
1647 #ifdef FEAT_DIFF
1648 /*
1649 * Switch from including filler lines below lp->lnum to including filler
1650 * lines above loff.lnum + 1. This keeps pointing to the same line.
1651 * When there are no filler lines nothing changes.
1652 */
1653 static void
1654 botline_topline(lp)
1655 lineoff_T *lp;
1656 {
1657 if (lp->fill > 0)
1658 {
1659 ++lp->lnum;
1660 lp->fill = diff_check_fill(curwin, lp->lnum) - lp->fill + 1;
1661 }
1662 }
1663
1664 /*
1665 * Switch from including filler lines above lp->lnum to including filler
1666 * lines below loff.lnum - 1. This keeps pointing to the same line.
1667 * When there are no filler lines nothing changes.
1668 */
1669 static void
1670 topline_botline(lp)
1671 lineoff_T *lp;
1672 {
1673 if (lp->fill > 0)
1674 {
1675 lp->fill = diff_check_fill(curwin, lp->lnum) - lp->fill + 1;
1676 --lp->lnum;
1677 }
1678 }
1679 #endif
1680
1681 /*
1682 * Recompute topline to put the cursor at the top of the window.
1683 * Scroll at least "min_scroll" lines.
1684 * If "always" is TRUE, always set topline (for "zt").
1685 */
1686 void
1687 scroll_cursor_top(min_scroll, always)
1688 int min_scroll;
1689 int always;
1690 {
1691 int scrolled = 0;
1692 int extra = 0;
1693 int used;
1694 int i;
1695 linenr_T top; /* just above displayed lines */
1696 linenr_T bot; /* just below displayed lines */
1697 linenr_T old_topline = curwin->w_topline;
1698 #ifdef FEAT_DIFF
1699 linenr_T old_topfill = curwin->w_topfill;
1700 #endif
1701 linenr_T new_topline;
1702 int off = p_so;
1703
1704 #ifdef FEAT_MOUSE
1705 if (mouse_dragging > 0)
1706 off = mouse_dragging - 1;
1707 #endif
1708
1709 /*
1710 * Decrease topline until:
1711 * - it has become 1
1712 * - (part of) the cursor line is moved off the screen or
1713 * - moved at least 'scrolljump' lines and
1714 * - at least 'scrolloff' lines above and below the cursor
1715 */
1716 validate_cheight();
1717 used = curwin->w_cline_height;
1718 if (curwin->w_cursor.lnum < curwin->w_topline)
1719 scrolled = used;
1720
1721 #ifdef FEAT_FOLDING
1722 if (hasFolding(curwin->w_cursor.lnum, &top, &bot))
1723 {
1724 --top;
1725 ++bot;
1726 }
1727 else
1728 #endif
1729 {
1730 top = curwin->w_cursor.lnum - 1;
1731 bot = curwin->w_cursor.lnum + 1;
1732 }
1733 new_topline = top + 1;
1734
1735 #ifdef FEAT_DIFF
1736 /* count filler lines of the cursor window as context */
1737 i = diff_check_fill(curwin, curwin->w_cursor.lnum);
1738 used += i;
1739 extra += i;
1740 #endif
1741
1742 /*
1743 * Check if the lines from "top" to "bot" fit in the window. If they do,
1744 * set new_topline and advance "top" and "bot" to include more lines.
1745 */
1746 while (top > 0)
1747 {
1748 #ifdef FEAT_FOLDING
1749 if (hasFolding(top, &top, NULL))
1750 /* count one logical line for a sequence of folded lines */
1751 i = 1;
1752 else
1753 #endif
1754 i = plines(top);
1755 used += i;
1756 if (extra + i <= off && bot < curbuf->b_ml.ml_line_count)
1757 {
1758 #ifdef FEAT_FOLDING
1759 if (hasFolding(bot, NULL, &bot))
1760 /* count one logical line for a sequence of folded lines */
1761 ++used;
1762 else
1763 #endif
1764 used += plines(bot);
1765 }
1766 if (used > curwin->w_height)
1767 break;
1768 if (top < curwin->w_topline)
1769 scrolled += i;
1770
1771 /*
1772 * If scrolling is needed, scroll at least 'sj' lines.
1773 */
1774 if ((new_topline >= curwin->w_topline || scrolled > min_scroll)
1775 && extra >= off)
1776 break;
1777
1778 extra += i;
1779 new_topline = top;
1780 --top;
1781 ++bot;
1782 }
1783
1784 /*
1785 * If we don't have enough space, put cursor in the middle.
1786 * This makes sure we get the same position when using "k" and "j"
1787 * in a small window.
1788 */
1789 if (used > curwin->w_height)
1790 scroll_cursor_halfway(FALSE);
1791 else
1792 {
1793 /*
1794 * If "always" is FALSE, only adjust topline to a lower value, higher
1795 * value may happen with wrapping lines
1796 */
1797 if (new_topline < curwin->w_topline || always)
1798 curwin->w_topline = new_topline;
1799 if (curwin->w_topline > curwin->w_cursor.lnum)
1800 curwin->w_topline = curwin->w_cursor.lnum;
1801 #ifdef FEAT_DIFF
1802 curwin->w_topfill = diff_check_fill(curwin, curwin->w_topline);
1803 if (curwin->w_topfill > 0 && extra > off)
1804 {
1805 curwin->w_topfill -= extra - off;
1806 if (curwin->w_topfill < 0)
1807 curwin->w_topfill = 0;
1808 }
1809 check_topfill(curwin, FALSE);
1810 #endif
1811 if (curwin->w_topline != old_topline
1812 #ifdef FEAT_DIFF
1813 || curwin->w_topfill != old_topfill
1814 #endif
1815 )
1816 curwin->w_valid &=
1817 ~(VALID_WROW|VALID_CROW|VALID_BOTLINE|VALID_BOTLINE_AP);
1818 curwin->w_valid |= VALID_TOPLINE;
1819 }
1820 }
1821
1822 /*
1823 * Set w_empty_rows and w_filler_rows for window "wp", having used up "used"
1824 * screen lines for text lines.
1825 */
1826 void
1827 set_empty_rows(wp, used)
1828 win_T *wp;
1829 int used;
1830 {
1831 #ifdef FEAT_DIFF
1832 wp->w_filler_rows = 0;
1833 #endif
1834 if (used == 0)
1835 wp->w_empty_rows = 0; /* single line that doesn't fit */
1836 else
1837 {
1838 wp->w_empty_rows = wp->w_height - used;
1839 #ifdef FEAT_DIFF
1840 if (wp->w_botline <= wp->w_buffer->b_ml.ml_line_count)
1841 {
1842 wp->w_filler_rows = diff_check_fill(wp, wp->w_botline);
1843 if (wp->w_empty_rows > wp->w_filler_rows)
1844 wp->w_empty_rows -= wp->w_filler_rows;
1845 else
1846 {
1847 wp->w_filler_rows = wp->w_empty_rows;
1848 wp->w_empty_rows = 0;
1849 }
1850 }
1851 #endif
1852 }
1853 }
1854
1855 /*
1856 * Recompute topline to put the cursor at the bottom of the window.
1857 * Scroll at least "min_scroll" lines.
1858 * If "set_topbot" is TRUE, set topline and botline first (for "zb").
1859 * This is messy stuff!!!
1860 */
1861 void
1862 scroll_cursor_bot(min_scroll, set_topbot)
1863 int min_scroll;
1864 int set_topbot;
1865 {
1866 int used;
1867 int scrolled = 0;
1868 int extra = 0;
1869 int i;
1870 linenr_T line_count;
1871 linenr_T old_topline = curwin->w_topline;
1872 lineoff_T loff;
1873 lineoff_T boff;
1874 #ifdef FEAT_DIFF
1875 int old_topfill = curwin->w_topfill;
1876 int fill_below_window;
1877 #endif
1878 linenr_T old_botline = curwin->w_botline;
1879 linenr_T old_valid = curwin->w_valid;
1880 int old_empty_rows = curwin->w_empty_rows;
1881 linenr_T cln; /* Cursor Line Number */
1882
1883 cln = curwin->w_cursor.lnum;
1884 if (set_topbot)
1885 {
1886 used = 0;
1887 curwin->w_botline = cln + 1;
1888 #ifdef FEAT_DIFF
1889 loff.fill = 0;
1890 #endif
1891 for (curwin->w_topline = curwin->w_botline;
1892 curwin->w_topline > 1;
1893 curwin->w_topline = loff.lnum)
1894 {
1895 loff.lnum = curwin->w_topline;
1896 topline_back(&loff);
1897 if (used + loff.height > curwin->w_height)
1898 break;
1899 used += loff.height;
1900 #ifdef FEAT_DIFF
1901 curwin->w_topfill = loff.fill;
1902 #endif
1903 }
1904 set_empty_rows(curwin, used);
1905 curwin->w_valid |= VALID_BOTLINE|VALID_BOTLINE_AP;
1906 if (curwin->w_topline != old_topline
1907 #ifdef FEAT_DIFF
1908 || curwin->w_topfill != old_topfill
1909 #endif
1910 )
1911 curwin->w_valid &= ~(VALID_WROW|VALID_CROW);
1912 }
1913 else
1914 validate_botline();
1915
1916 /* The lines of the cursor line itself are always used. */
1917 #ifdef FEAT_DIFF
1918 used = plines_nofill(cln);
1919 #else
1920 validate_cheight();
1921 used = curwin->w_cline_height;
1922 #endif
1923
1924 /* If the cursor is below botline, we will at least scroll by the height
1925 * of the cursor line. Correct for empty lines, which are really part of
1926 * botline. */
1927 if (cln >= curwin->w_botline)
1928 {
1929 scrolled = used;
1930 if (cln == curwin->w_botline)
1931 scrolled -= curwin->w_empty_rows;
1932 }
1933
1934 /*
1935 * Stop counting lines to scroll when
1936 * - hitting start of the file
1937 * - scrolled nothing or at least 'sj' lines
1938 * - at least 'so' lines below the cursor
1939 * - lines between botline and cursor have been counted
1940 */
1941 #ifdef FEAT_FOLDING
1942 if (!hasFolding(curwin->w_cursor.lnum, &loff.lnum, &boff.lnum))
1943 #endif
1944 {
1945 loff.lnum = cln;
1946 boff.lnum = cln;
1947 }
1948 #ifdef FEAT_DIFF
1949 loff.fill = 0;
1950 boff.fill = 0;
1951 fill_below_window = diff_check_fill(curwin, curwin->w_botline)
1952 - curwin->w_filler_rows;
1953 #endif
1954
1955 while (loff.lnum > 1)
1956 {
1957 /* Stop when scrolled nothing or at least "min_scroll", found "extra"
1958 * context for 'scrolloff' and counted all lines below the window. */
1959 if ((((scrolled <= 0 || scrolled >= min_scroll)
1960 && extra >= (
1961 #ifdef FEAT_MOUSE
1962 mouse_dragging ? mouse_dragging - 1 :
1963 #endif
1964 p_so))
1965 || boff.lnum + 1 > curbuf->b_ml.ml_line_count)
1966 && loff.lnum <= curwin->w_botline
1967 #ifdef FEAT_DIFF
1968 && (loff.lnum < curwin->w_botline
1969 || loff.fill >= fill_below_window)
1970 #endif
1971 )
1972 break;
1973
1974 /* Add one line above */
1975 topline_back(&loff);
1976 used += loff.height;
1977 if (used > curwin->w_height)
1978 break;
1979 if (loff.lnum >= curwin->w_botline
1980 #ifdef FEAT_DIFF
1981 && (loff.lnum > curwin->w_botline
1982 || loff.fill <= fill_below_window)
1983 #endif
1984 )
1985 {
1986 /* Count screen lines that are below the window. */
1987 scrolled += loff.height;
1988 if (loff.lnum == curwin->w_botline
1989 #ifdef FEAT_DIFF
1990 && boff.fill == 0
1991 #endif
1992 )
1993 scrolled -= curwin->w_empty_rows;
1994 }
1995
1996 if (boff.lnum < curbuf->b_ml.ml_line_count)
1997 {
1998 /* Add one line below */
1999 botline_forw(&boff);
2000 used += boff.height;
2001 if (used > curwin->w_height)
2002 break;
2003 if (extra < (
2004 #ifdef FEAT_MOUSE
2005 mouse_dragging > 0 ? mouse_dragging - 1 :
2006 #endif
2007 p_so) || scrolled < min_scroll)
2008 {
2009 extra += boff.height;
2010 if (boff.lnum >= curwin->w_botline
2011 #ifdef FEAT_DIFF
2012 || (boff.lnum + 1 == curwin->w_botline
2013 && boff.fill > curwin->w_filler_rows)
2014 #endif
2015 )
2016 {
2017 /* Count screen lines that are below the window. */
2018 scrolled += boff.height;
2019 if (boff.lnum == curwin->w_botline
2020 #ifdef FEAT_DIFF
2021 && boff.fill == 0
2022 #endif
2023 )
2024 scrolled -= curwin->w_empty_rows;
2025 }
2026 }
2027 }
2028 }
2029
2030 /* curwin->w_empty_rows is larger, no need to scroll */
2031 if (scrolled <= 0)
2032 line_count = 0;
2033 /* more than a screenfull, don't scroll but redraw */
2034 else if (used > curwin->w_height)
2035 line_count = used;
2036 /* scroll minimal number of lines */
2037 else
2038 {
2039 line_count = 0;
2040 #ifdef FEAT_DIFF
2041 boff.fill = curwin->w_topfill;
2042 #endif
2043 boff.lnum = curwin->w_topline - 1;
2044 for (i = 0; i < scrolled && boff.lnum < curwin->w_botline; )
2045 {
2046 botline_forw(&boff);
2047 i += boff.height;
2048 ++line_count;
2049 }
2050 if (i < scrolled) /* below curwin->w_botline, don't scroll */
2051 line_count = 9999;
2052 }
2053
2054 /*
2055 * Scroll up if the cursor is off the bottom of the screen a bit.
2056 * Otherwise put it at 1/2 of the screen.
2057 */
2058 if (line_count >= curwin->w_height && line_count > min_scroll)
2059 scroll_cursor_halfway(FALSE);
2060 else
2061 scrollup(line_count, TRUE);
2062
2063 /*
2064 * If topline didn't change we need to restore w_botline and w_empty_rows
2065 * (we changed them).
2066 * If topline did change, update_screen() will set botline.
2067 */
2068 if (curwin->w_topline == old_topline && set_topbot)
2069 {
2070 curwin->w_botline = old_botline;
2071 curwin->w_empty_rows = old_empty_rows;
2072 curwin->w_valid = old_valid;
2073 }
2074 curwin->w_valid |= VALID_TOPLINE;
2075 }
2076
2077 /*
2078 * Recompute topline to put the cursor halfway the window
2079 * If "atend" is TRUE, also put it halfway at the end of the file.
2080 */
2081 void
2082 scroll_cursor_halfway(atend)
2083 int atend;
2084 {
2085 int above = 0;
2086 linenr_T topline;
2087 #ifdef FEAT_DIFF
2088 int topfill = 0;
2089 #endif
2090 int below = 0;
2091 int used;
2092 lineoff_T loff;
2093 lineoff_T boff;
2094
2095 loff.lnum = boff.lnum = curwin->w_cursor.lnum;
2096 #ifdef FEAT_FOLDING
2097 (void)hasFolding(loff.lnum, &loff.lnum, &boff.lnum);
2098 #endif
2099 #ifdef FEAT_DIFF
2100 used = plines_nofill(loff.lnum);
2101 loff.fill = 0;
2102 boff.fill = 0;
2103 #else
2104 used = plines(loff.lnum);
2105 #endif
2106 topline = loff.lnum;
2107 while (topline > 1)
2108 {
2109 if (below <= above) /* add a line below the cursor first */
2110 {
2111 if (boff.lnum < curbuf->b_ml.ml_line_count)
2112 {
2113 botline_forw(&boff);
2114 used += boff.height;
2115 if (used > curwin->w_height)
2116 break;
2117 below += boff.height;
2118 }
2119 else
2120 {
2121 ++below; /* count a "~" line */
2122 if (atend)
2123 ++used;
2124 }
2125 }
2126
2127 if (below > above) /* add a line above the cursor */
2128 {
2129 topline_back(&loff);
2130 used += loff.height;
2131 if (used > curwin->w_height)
2132 break;
2133 above += loff.height;
2134 topline = loff.lnum;
2135 #ifdef FEAT_DIFF
2136 topfill = loff.fill;
2137 #endif
2138 }
2139 }
2140 #ifdef FEAT_FOLDING
2141 if (!hasFolding(topline, &curwin->w_topline, NULL))
2142 #endif
2143 curwin->w_topline = topline;
2144 #ifdef FEAT_DIFF
2145 curwin->w_topfill = topfill;
2146 check_topfill(curwin, FALSE);
2147 #endif
2148 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE|VALID_BOTLINE_AP);
2149 curwin->w_valid |= VALID_TOPLINE;
2150 }
2151
2152 /*
2153 * Correct the cursor position so that it is in a part of the screen at least
2154 * 'so' lines from the top and bottom, if possible.
2155 * If not possible, put it at the same position as scroll_cursor_halfway().
2156 * When called topline must be valid!
2157 */
2158 void
2159 cursor_correct()
2160 {
2161 int above = 0; /* screen lines above topline */
2162 linenr_T topline;
2163 int below = 0; /* screen lines below botline */
2164 linenr_T botline;
2165 int above_wanted, below_wanted;
2166 linenr_T cln; /* Cursor Line Number */
2167 int max_off;
2168
2169 /*
2170 * How many lines we would like to have above/below the cursor depends on
2171 * whether the first/last line of the file is on screen.
2172 */
2173 above_wanted = p_so;
2174 below_wanted = p_so;
2175 #ifdef FEAT_MOUSE
2176 if (mouse_dragging)
2177 {
2178 above_wanted = mouse_dragging - 1;
2179 below_wanted = mouse_dragging - 1;
2180 }
2181 #endif
2182 if (curwin->w_topline == 1)
2183 {
2184 above_wanted = 0;
2185 max_off = curwin->w_height / 2;
2186 if (below_wanted > max_off)
2187 below_wanted = max_off;
2188 }
2189 validate_botline();
2190 if (curwin->w_botline == curbuf->b_ml.ml_line_count + 1
2191 #ifdef FEAT_MOUSE
2192 && !mouse_dragging
2193 #endif
2194 )
2195 {
2196 below_wanted = 0;
2197 max_off = (curwin->w_height - 1) / 2;
2198 if (above_wanted > max_off)
2199 above_wanted = max_off;
2200 }
2201
2202 /*
2203 * If there are sufficient file-lines above and below the cursor, we can
2204 * return now.
2205 */
2206 cln = curwin->w_cursor.lnum;
2207 if (cln >= curwin->w_topline + above_wanted
2208 && cln < curwin->w_botline - below_wanted
2209 #ifdef FEAT_FOLDING
2210 && !hasAnyFolding(curwin)
2211 #endif
2212 )
2213 return;
2214
2215 /*
2216 * Narrow down the area where the cursor can be put by taking lines from
2217 * the top and the bottom until:
2218 * - the desired context lines are found
2219 * - the lines from the top is past the lines from the bottom
2220 */
2221 topline = curwin->w_topline;
2222 botline = curwin->w_botline - 1;
2223 #ifdef FEAT_DIFF
2224 /* count filler lines as context */
2225 above = curwin->w_topfill;
2226 below = curwin->w_filler_rows;
2227 #endif
2228 while ((above < above_wanted || below < below_wanted) && topline < botline)
2229 {
2230 if (below < below_wanted && (below <= above || above >= above_wanted))
2231 {
2232 #ifdef FEAT_FOLDING
2233 if (hasFolding(botline, &botline, NULL))
2234 ++below;
2235 else
2236 #endif
2237 below += plines(botline);
2238 --botline;
2239 }
2240 if (above < above_wanted && (above < below || below >= below_wanted))
2241 {
2242 #ifdef FEAT_FOLDING
2243 if (hasFolding(topline, NULL, &topline))
2244 ++above;
2245 else
2246 #endif
2247 #ifndef FEAT_DIFF
2248 above += plines(topline);
2249 #else
2250 above += plines_nofill(topline);
2251
2252 /* Count filler lines below this line as context. */
2253 if (topline < botline)
2254 above += diff_check_fill(curwin, topline + 1);
2255 #endif
2256 ++topline;
2257 }
2258 }
2259 if (topline == botline || botline == 0)
2260 curwin->w_cursor.lnum = topline;
2261 else if (topline > botline)
2262 curwin->w_cursor.lnum = botline;
2263 else
2264 {
2265 if (cln < topline && curwin->w_topline > 1)
2266 {
2267 curwin->w_cursor.lnum = topline;
2268 curwin->w_valid &=
2269 ~(VALID_WROW|VALID_WCOL|VALID_CHEIGHT|VALID_CROW);
2270 }
2271 if (cln > botline && curwin->w_botline <= curbuf->b_ml.ml_line_count)
2272 {
2273 curwin->w_cursor.lnum = botline;
2274 curwin->w_valid &=
2275 ~(VALID_WROW|VALID_WCOL|VALID_CHEIGHT|VALID_CROW);
2276 }
2277 }
2278 curwin->w_valid |= VALID_TOPLINE;
2279 }
2280
2281 static void get_scroll_overlap __ARGS((lineoff_T *lp, int dir));
2282
2283 /*
2284 * move screen 'count' pages up or down and update screen
2285 *
2286 * return FAIL for failure, OK otherwise
2287 */
2288 int
2289 onepage(dir, count)
2290 int dir;
2291 long count;
2292 {
2293 long n;
2294 int retval = OK;
2295 lineoff_T loff;
2296 linenr_T old_topline = curwin->w_topline;
2297
2298 if (curbuf->b_ml.ml_line_count == 1) /* nothing to do */
2299 {
2300 beep_flush();
2301 return FAIL;
2302 }
2303
2304 for ( ; count > 0; --count)
2305 {
2306 validate_botline();
2307 /*
2308 * It's an error to move a page up when the first line is already on
2309 * the screen. It's an error to move a page down when the last line
2310 * is on the screen and the topline is 'scrolloff' lines from the
2311 * last line.
2312 */
2313 if (dir == FORWARD
2314 ? ((curwin->w_topline >= curbuf->b_ml.ml_line_count - p_so)
2315 && curwin->w_botline > curbuf->b_ml.ml_line_count)
2316 : (curwin->w_topline == 1
2317 #ifdef FEAT_DIFF
2318 && curwin->w_topfill ==
2319 diff_check_fill(curwin, curwin->w_topline)
2320 #endif
2321 ))
2322 {
2323 beep_flush();
2324 retval = FAIL;
2325 break;
2326 }
2327
2328 #ifdef FEAT_DIFF
2329 loff.fill = 0;
2330 #endif
2331 if (dir == FORWARD)
2332 {
2333 /* at end of file */
2334 if (curwin->w_botline > curbuf->b_ml.ml_line_count)
2335 {
2336 curwin->w_topline = curbuf->b_ml.ml_line_count;
2337 #ifdef FEAT_DIFF
2338 curwin->w_topfill = 0;
2339 #endif
2340 curwin->w_valid &= ~(VALID_WROW|VALID_CROW);
2341 }
2342 else
2343 {
2344 /* For the overlap, start with the line just below the window
2345 * and go upwards. */
2346 loff.lnum = curwin->w_botline;
2347 #ifdef FEAT_DIFF
2348 loff.fill = diff_check_fill(curwin, loff.lnum)
2349 - curwin->w_filler_rows;
2350 #endif
2351 get_scroll_overlap(&loff, -1);
2352 curwin->w_topline = loff.lnum;
2353 #ifdef FEAT_DIFF
2354 curwin->w_topfill = loff.fill;
2355 check_topfill(curwin, FALSE);
2356 #endif
2357 curwin->w_cursor.lnum = curwin->w_topline;
2358 curwin->w_valid &= ~(VALID_WCOL|VALID_CHEIGHT|VALID_WROW|
2359 VALID_CROW|VALID_BOTLINE|VALID_BOTLINE_AP);
2360 }
2361 }
2362 else /* dir == BACKWARDS */
2363 {
2364 #ifdef FEAT_DIFF
2365 if (curwin->w_topline == 1)
2366 {
2367 /* Include max number of filler lines */
2368 max_topfill();
2369 continue;
2370 }
2371 #endif
2372 /* Find the line at the top of the window that is going to be the
2373 * line at the bottom of the window. Make sure this results in
2374 * the same line as before doing CTRL-F. */
2375 loff.lnum = curwin->w_topline - 1;
2376 #ifdef FEAT_DIFF
2377 loff.fill = diff_check_fill(curwin, loff.lnum + 1)
2378 - curwin->w_topfill;
2379 #endif
2380 get_scroll_overlap(&loff, 1);
2381
2382 if (loff.lnum >= curbuf->b_ml.ml_line_count)
2383 {
2384 loff.lnum = curbuf->b_ml.ml_line_count;
2385 #ifdef FEAT_DIFF
2386 loff.fill = 0;
2387 }
2388 else
2389 {
2390 botline_topline(&loff);
2391 #endif
2392 }
2393 curwin->w_cursor.lnum = loff.lnum;
2394
2395 /* Find the line just above the new topline to get the right line
2396 * at the bottom of the window. */
2397 n = 0;
2398 while (n <= curwin->w_height && loff.lnum >= 1)
2399 {
2400 topline_back(&loff);
2401 n += loff.height;
2402 }
2403 if (n <= curwin->w_height) /* at begin of file */
2404 {
2405 curwin->w_topline = 1;
2406 #ifdef FEAT_DIFF
2407 max_topfill();
2408 #endif
2409 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE);
2410 }
2411 else
2412 {
2413 /* Go two lines forward again. */
2414 #ifdef FEAT_DIFF
2415 topline_botline(&loff);
2416 #endif
2417 botline_forw(&loff);
2418 botline_forw(&loff);
2419 #ifdef FEAT_DIFF
2420 botline_topline(&loff);
2421 #endif
2422 #ifdef FEAT_FOLDING
2423 /* We're at the wrong end of a fold now. */
2424 (void)hasFolding(loff.lnum, &loff.lnum, NULL);
2425 #endif
2426
2427 /* Always scroll at least one line. Avoid getting stuck on
2428 * very long lines. */
2429 if (loff.lnum >= curwin->w_topline
2430 #ifdef FEAT_DIFF
2431 && (loff.lnum > curwin->w_topline
2432 || loff.fill >= curwin->w_topfill)
2433 #endif
2434 )
2435 {
2436 #ifdef FEAT_DIFF
2437 /* First try using the maximum number of filler lines. If
2438 * that's not enough, backup one line. */
2439 loff.fill = curwin->w_topfill;
2440 if (curwin->w_topfill < diff_check_fill(curwin,
2441 curwin->w_topline))
2442 max_topfill();
2443 if (curwin->w_topfill == loff.fill)
2444 #endif
2445 {
2446 --curwin->w_topline;
2447 #ifdef FEAT_DIFF
2448 curwin->w_topfill = 0;
2449 #endif
2450 }
2451 comp_botline(curwin);
2452 curwin->w_cursor.lnum = curwin->w_botline - 1;
2453 curwin->w_valid &= ~(VALID_WCOL|VALID_CHEIGHT|
2454 VALID_WROW|VALID_CROW);
2455 }
2456 else
2457 {
2458 curwin->w_topline = loff.lnum;
2459 #ifdef FEAT_DIFF
2460 curwin->w_topfill = loff.fill;
2461 check_topfill(curwin, FALSE);
2462 #endif
2463 curwin->w_valid &= ~(VALID_WROW|VALID_CROW|VALID_BOTLINE);
2464 }
2465 }
2466 }
2467 }
2468 #ifdef FEAT_FOLDING
2469 foldAdjustCursor();
2470 #endif
2471 cursor_correct();
2472 beginline(BL_SOL | BL_FIX);
2473 curwin->w_valid &= ~(VALID_WCOL|VALID_WROW|VALID_VIRTCOL);
2474
2475 /*
2476 * Avoid the screen jumping up and down when 'scrolloff' is non-zero.
2477 * But make sure we scroll at least one line (happens with mix of long
2478 * wrapping lines and non-wrapping line).
2479 */
2480 if (retval == OK && dir == FORWARD && check_top_offset())
2481 {
2482 scroll_cursor_top(1, FALSE);
2483 if (curwin->w_topline <= old_topline
2484 && old_topline < curbuf->b_ml.ml_line_count)
2485 {
2486 curwin->w_topline = old_topline + 1;
2487 #ifdef FEAT_FOLDING
2488 (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
2489 #endif
2490 }
2491 }
2492
2493 redraw_later(VALID);
2494 return retval;
2495 }
2496
2497 /*
2498 * Decide how much overlap to use for page-up or page-down scrolling.
2499 * This is symmetric, so that doing both keeps the same lines displayed.
2500 * Three lines are examined:
2501 *
2502 * before CTRL-F after CTRL-F / before CTRL-B
2503 * etc. l1
2504 * l1 last but one line ------------
2505 * l2 last text line l2 top text line
2506 * ------------- l3 second text line
2507 * l3 etc.
2508 */
2509 static void
2510 get_scroll_overlap(lp, dir)
2511 lineoff_T *lp;
2512 int dir;
2513 {
2514 int h1, h2, h3, h4;
2515 int min_height = curwin->w_height - 2;
2516 lineoff_T loff0, loff1, loff2;
2517
2518 #ifdef FEAT_DIFF
2519 if (lp->fill > 0)
2520 lp->height = 1;
2521 else
2522 lp->height = plines_nofill(lp->lnum);
2523 #else
2524 lp->height = plines(lp->lnum);
2525 #endif
2526 h1 = lp->height;
2527 if (h1 > min_height)
2528 return; /* no overlap */
2529
2530 loff0 = *lp;
2531 if (dir > 0)
2532 botline_forw(lp);
2533 else
2534 topline_back(lp);
2535 h2 = lp->height;
2536 if (h2 + h1 > min_height)
2537 {
2538 *lp = loff0; /* no overlap */
2539 return;
2540 }
2541
2542 loff1 = *lp;
2543 if (dir > 0)
2544 botline_forw(lp);
2545 else
2546 topline_back(lp);
2547 h3 = lp->height;
2548 if (h3 + h2 > min_height)
2549 {
2550 *lp = loff0; /* no overlap */
2551 return;
2552 }
2553
2554 loff2 = *lp;
2555 if (dir > 0)
2556 botline_forw(lp);
2557 else
2558 topline_back(lp);
2559 h4 = lp->height;
2560 if (h4 + h3 + h2 > min_height || h3 + h2 + h1 > min_height)
2561 *lp = loff1; /* 1 line overlap */
2562 else
2563 *lp = loff2; /* 2 lines overlap */
2564 return;
2565 }
2566
2567 /* #define KEEP_SCREEN_LINE */
2568 /*
2569 * Scroll 'scroll' lines up or down.
2570 */
2571 void
2572 halfpage(flag, Prenum)
2573 int flag;
2574 linenr_T Prenum;
2575 {
2576 long scrolled = 0;
2577 int i;
2578 int n;
2579 int room;
2580
2581 if (Prenum)
2582 curwin->w_p_scr = (Prenum > curwin->w_height) ?
2583 curwin->w_height : Prenum;
2584 n = (curwin->w_p_scr <= curwin->w_height) ?
2585 curwin->w_p_scr : curwin->w_height;
2586
2587 validate_botline();
2588 room = curwin->w_empty_rows;
2589 #ifdef FEAT_DIFF
2590 room += curwin->w_filler_rows;
2591 #endif
2592 if (flag)
2593 {
2594 /*
2595 * scroll the text up
2596 */
2597 while (n > 0 && curwin->w_botline <= curbuf->b_ml.ml_line_count)
2598 {
2599 #ifdef FEAT_DIFF
2600 if (curwin->w_topfill > 0)
2601 {
2602 i = 1;
2603 if (--n < 0 && scrolled > 0)
2604 break;
2605 --curwin->w_topfill;
2606 }
2607 else
2608 #endif
2609 {
2610 #ifdef FEAT_DIFF
2611 i = plines_nofill(curwin->w_topline);
2612 #else
2613 i = plines(curwin->w_topline);
2614 #endif
2615 n -= i;
2616 if (n < 0 && scrolled > 0)
2617 break;
2618 #ifdef FEAT_FOLDING
2619 (void)hasFolding(curwin->w_topline, NULL, &curwin->w_topline);
2620 #endif
2621 ++curwin->w_topline;
2622 #ifdef FEAT_DIFF
2623 curwin->w_topfill = diff_check_fill(curwin, curwin->w_topline);
2624 #endif
2625
2626 #ifndef KEEP_SCREEN_LINE
2627 if (curwin->w_cursor.lnum < curbuf->b_ml.ml_line_count)
2628 {
2629 ++curwin->w_cursor.lnum;
2630 curwin->w_valid &=
2631 ~(VALID_VIRTCOL|VALID_CHEIGHT|VALID_WCOL);
2632 }
2633 #endif
2634 }
2635 curwin->w_valid &= ~(VALID_CROW|VALID_WROW);
2636 scrolled += i;
2637
2638 /*
2639 * Correct w_botline for changed w_topline.
2640 * Won't work when there are filler lines.
2641 */
2642 #ifdef FEAT_DIFF
2643 if (curwin->w_p_diff)
2644 curwin->w_valid &= ~(VALID_BOTLINE|VALID_BOTLINE_AP);
2645 else
2646 #endif
2647 {
2648 room += i;
2649 do
2650 {
2651 i = plines(curwin->w_botline);
2652 if (i > room)
2653 break;
2654 #ifdef FEAT_FOLDING
2655 (void)hasFolding(curwin->w_botline, NULL,
2656 &curwin->w_botline);
2657 #endif
2658 ++curwin->w_botline;
2659 room -= i;
2660 } while (curwin->w_botline <= curbuf->b_ml.ml_line_count);
2661 }
2662 }
2663
2664 #ifndef KEEP_SCREEN_LINE
2665 /*
2666 * When hit bottom of the file: move cursor down.
2667 */
2668 if (n > 0)
2669 {
2670 # ifdef FEAT_FOLDING
2671 if (hasAnyFolding(curwin))
2672 {
2673 while (--n >= 0
2674 && curwin->w_cursor.lnum < curbuf->b_ml.ml_line_count)
2675 {
2676 (void)hasFolding(curwin->w_cursor.lnum, NULL,
2677 &curwin->w_cursor.lnum);
2678 ++curwin->w_cursor.lnum;
2679 }
2680 }
2681 else
2682 # endif
2683 curwin->w_cursor.lnum += n;
2684 check_cursor_lnum();
2685 }
2686 #else
2687 /* try to put the cursor in the same screen line */
2688 while ((curwin->w_cursor.lnum < curwin->w_topline || scrolled > 0)
2689 && curwin->w_cursor.lnum < curwin->w_botline - 1)
2690 {
2691 scrolled -= plines(curwin->w_cursor.lnum);
2692 if (scrolled < 0 && curwin->w_cursor.lnum >= curwin->w_topline)
2693 break;
2694 # ifdef FEAT_FOLDING
2695 (void)hasFolding(curwin->w_cursor.lnum, NULL,
2696 &curwin->w_cursor.lnum);
2697 # endif
2698 ++curwin->w_cursor.lnum;
2699 }
2700 #endif
2701 }
2702 else
2703 {
2704 /*
2705 * scroll the text down
2706 */
2707 while (n > 0 && curwin->w_topline > 1)
2708 {
2709 #ifdef FEAT_DIFF
2710 if (curwin->w_topfill < diff_check_fill(curwin, curwin->w_topline))
2711 {
2712 i = 1;
2713 if (--n < 0 && scrolled > 0)
2714 break;
2715 ++curwin->w_topfill;
2716 }
2717 else
2718 #endif
2719 {
2720 #ifdef FEAT_DIFF
2721 i = plines_nofill(curwin->w_topline - 1);
2722 #else
2723 i = plines(curwin->w_topline - 1);
2724 #endif
2725 n -= i;
2726 if (n < 0 && scrolled > 0)
2727 break;
2728 --curwin->w_topline;
2729 #ifdef FEAT_FOLDING
2730 (void)hasFolding(curwin->w_topline, &curwin->w_topline, NULL);
2731 #endif
2732 #ifdef FEAT_DIFF
2733 curwin->w_topfill = 0;
2734 #endif
2735 }
2736 curwin->w_valid &= ~(VALID_CROW|VALID_WROW|
2737 VALID_BOTLINE|VALID_BOTLINE_AP);
2738 scrolled += i;
2739 #ifndef KEEP_SCREEN_LINE
2740 if (curwin->w_cursor.lnum > 1)
2741 {
2742 --curwin->w_cursor.lnum;
2743 curwin->w_valid &= ~(VALID_VIRTCOL|VALID_CHEIGHT|VALID_WCOL);
2744 }
2745 #endif
2746 }
2747 #ifndef KEEP_SCREEN_LINE
2748 /*
2749 * When hit top of the file: move cursor up.
2750 */
2751 if (n > 0)
2752 {
2753 if (curwin->w_cursor.lnum <= (linenr_T)n)
2754 curwin->w_cursor.lnum = 1;
2755 else
2756 # ifdef FEAT_FOLDING
2757 if (hasAnyFolding(curwin))
2758 {
2759 while (--n >= 0 && curwin->w_cursor.lnum > 1)
2760 {
2761 --curwin->w_cursor.lnum;
2762 (void)hasFolding(curwin->w_cursor.lnum,
2763 &curwin->w_cursor.lnum, NULL);
2764 }
2765 }
2766 else
2767 # endif
2768 curwin->w_cursor.lnum -= n;
2769 }
2770 #else
2771 /* try to put the cursor in the same screen line */
2772 scrolled += n; /* move cursor when topline is 1 */
2773 while (curwin->w_cursor.lnum > curwin->w_topline
2774 && (scrolled > 0 || curwin->w_cursor.lnum >= curwin->w_botline))
2775 {
2776 scrolled -= plines(curwin->w_cursor.lnum - 1);
2777 if (scrolled < 0 && curwin->w_cursor.lnum < curwin->w_botline)
2778 break;
2779 --curwin->w_cursor.lnum;
2780 # ifdef FEAT_FOLDING
2781 foldAdjustCursor();
2782 # endif
2783 }
2784 #endif
2785 }
2786 # ifdef FEAT_FOLDING
2787 /* Move cursor to first line of closed fold. */
2788 foldAdjustCursor();
2789 # endif
2790 #ifdef FEAT_DIFF
2791 check_topfill(curwin, !flag);
2792 #endif
2793 cursor_correct();
2794 beginline(BL_SOL | BL_FIX);
2795 redraw_later(VALID);
2796 }