xref: /openbsd/usr.bin/vi/vi/vs_refresh.c (revision 39e743a5)
1 /*	$OpenBSD: vs_refresh.c,v 1.25 2024/04/25 09:58:17 job Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 #include <sys/time.h>
17 
18 #include <bitstring.h>
19 #include <ctype.h>
20 #include <libgen.h>
21 #include <limits.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "../common/common.h"
27 #include "vi.h"
28 
29 #define	UPDATE_CURSOR	0x01			/* Update the cursor. */
30 #define	UPDATE_SCREEN	0x02			/* Flush to screen. */
31 
32 static void	vs_modeline(SCR *);
33 static int	vs_paint(SCR *, u_int);
34 
35 /*
36  * v_repaint --
37  *	Repaint selected lines from the screen.
38  *
39  * PUBLIC: int vs_repaint(SCR *, EVENT *);
40  */
41 int
vs_repaint(SCR * sp,EVENT * evp)42 vs_repaint(SCR *sp, EVENT *evp)
43 {
44 	SMAP *smp;
45 
46 	for (; evp->e_flno <= evp->e_tlno; ++evp->e_flno) {
47 		smp = HMAP + evp->e_flno - 1;
48 		SMAP_FLUSH(smp);
49 		if (vs_line(sp, smp, NULL, NULL))
50 			return (1);
51 	}
52 	return (0);
53 }
54 
55 /*
56  * vs_refresh --
57  *	Refresh all screens.
58  *
59  * PUBLIC: int vs_refresh(SCR *, int);
60  */
61 int
vs_refresh(SCR * sp,int forcepaint)62 vs_refresh(SCR *sp, int forcepaint)
63 {
64 	GS *gp;
65 	SCR *tsp;
66 	int need_refresh;
67 	u_int priv_paint, pub_paint;
68 
69 	gp = sp->gp;
70 
71 	/*
72 	 * 1: Refresh the screen.
73 	 *
74 	 * If SC_SCR_REDRAW is set in the current screen, repaint everything
75 	 * that we can find, including status lines.
76 	 */
77 	if (F_ISSET(sp, SC_SCR_REDRAW))
78 		TAILQ_FOREACH(tsp, &gp->dq, q)
79 			if (tsp != sp)
80 				F_SET(tsp, SC_SCR_REDRAW | SC_STATUS);
81 
82 	/*
83 	 * 2: Related or dirtied screens, or screens with messages.
84 	 *
85 	 * If related screens share a view into a file, they may have been
86 	 * modified as well.  Refresh any screens that aren't exiting that
87 	 * have paint or dirty bits set.  Always update their screens, we
88 	 * are not likely to get another chance.  Finally, if we refresh any
89 	 * screens other than the current one, the cursor will be trashed.
90 	 */
91 	pub_paint = SC_SCR_REFORMAT | SC_SCR_REDRAW;
92 	priv_paint = VIP_CUR_INVALID | VIP_N_REFRESH;
93 	if (O_ISSET(sp, O_NUMBER))
94 		priv_paint |= VIP_N_RENUMBER;
95 	TAILQ_FOREACH(tsp, &gp->dq, q)
96 		if (tsp != sp && !F_ISSET(tsp, SC_EXIT | SC_EXIT_FORCE) &&
97 		    (F_ISSET(tsp, pub_paint) ||
98 		    F_ISSET(VIP(tsp), priv_paint))) {
99 			(void)vs_paint(tsp,
100 			    (F_ISSET(VIP(tsp), VIP_CUR_INVALID) ?
101 			    UPDATE_CURSOR : 0) | UPDATE_SCREEN);
102 			F_SET(VIP(sp), VIP_CUR_INVALID);
103 		}
104 
105 	/*
106 	 * 3: Refresh the current screen.
107 	 *
108 	 * Always refresh the current screen, it may be a cursor movement.
109 	 * Also, always do it last -- that way, SC_SCR_REDRAW can be set
110 	 * in the current screen only, and the screen won't flash.
111 	 */
112 	if (vs_paint(sp, UPDATE_CURSOR | (!forcepaint &&
113 	    F_ISSET(sp, SC_SCR_VI) && KEYS_WAITING(sp) ? 0 : UPDATE_SCREEN)))
114 		return (1);
115 
116 	/*
117 	 * 4: Paint any missing status lines.
118 	 *
119 	 * XXX
120 	 * This is fairly evil.  Status lines are written using the vi message
121 	 * mechanism, since we have no idea how long they are.  Since we may be
122 	 * painting screens other than the current one, we don't want to make
123 	 * the user wait.  We depend heavily on there not being any other lines
124 	 * currently waiting to be displayed and the message truncation code in
125 	 * the msgq_status routine working.
126 	 *
127 	 * And, finally, if we updated any status lines, make sure the cursor
128 	 * gets back to where it belongs.
129 	 */
130 	need_refresh = 0;
131 	TAILQ_FOREACH(tsp, &gp->dq, q)
132 		if (F_ISSET(tsp, SC_STATUS)) {
133 			need_refresh = 1;
134 			vs_resolve(tsp, sp, 0);
135 		}
136 	if (need_refresh)
137 		(void)gp->scr_refresh(sp, 0);
138 
139 	/*
140 	 * A side-effect of refreshing the screen is that it's now ready
141 	 * for everything else, i.e. messages.
142 	 */
143 	F_SET(sp, SC_SCR_VI);
144 	return (0);
145 }
146 
147 /*
148  * vs_paint --
149  *	This is the guts of the vi curses screen code.  The idea is that
150  *	the SCR structure passed in contains the new coordinates of the
151  *	screen.  What makes this hard is that we don't know how big
152  *	characters are, doing input can put the cursor in illegal places,
153  *	and we're frantically trying to avoid repainting unless it's
154  *	absolutely necessary.  If you change this code, you'd better know
155  *	what you're doing.  It's subtle and quick to anger.
156  */
157 static int
vs_paint(SCR * sp,u_int flags)158 vs_paint(SCR *sp, u_int flags)
159 {
160 	GS *gp;
161 	SMAP *smp, tmp;
162 	VI_PRIVATE *vip;
163 	recno_t lastline, lcnt;
164 	size_t cwtotal, cnt, len, notused, off, y;
165 	int ch = 0, didpaint, isempty, leftright_warp;
166 	char *p;
167 
168 #define	 LNO	sp->lno			/* Current file line. */
169 #define	OLNO	vip->olno		/* Remembered file line. */
170 #define	 CNO	sp->cno			/* Current file column. */
171 #define	OCNO	vip->ocno		/* Remembered file column. */
172 #define	SCNO	vip->sc_col		/* Current screen column. */
173 
174 	gp = sp->gp;
175 	vip = VIP(sp);
176 	didpaint = leftright_warp = 0;
177 
178 	/*
179 	 * 5: Reformat the lines.
180 	 *
181 	 * If the lines themselves have changed (:set list, for example),
182 	 * fill in the map from scratch.  Adjust the screen that's being
183 	 * displayed if the leftright flag is set.
184 	 */
185 	if (F_ISSET(sp, SC_SCR_REFORMAT)) {
186 		/* Invalidate the line size cache. */
187 		VI_SCR_CFLUSH(vip);
188 
189 		/* Toss vs_line() cached information. */
190 		if (F_ISSET(sp, SC_SCR_TOP)) {
191 			if (vs_sm_fill(sp, LNO, P_TOP))
192 				return (1);
193 		}
194 		else if (F_ISSET(sp, SC_SCR_CENTER)) {
195 			if (vs_sm_fill(sp, LNO, P_MIDDLE))
196 				return (1);
197 		} else {
198 			if (LNO == HMAP->lno || LNO == TMAP->lno) {
199 				cnt = vs_screens(sp, LNO, &CNO);
200 				if (LNO == HMAP->lno && cnt < HMAP->soff)
201 					HMAP->soff = cnt;
202 				if (LNO == TMAP->lno && cnt > TMAP->soff)
203 					TMAP->soff = cnt;
204 			}
205 
206 			if (vs_sm_fill(sp, OOBLNO, P_TOP))
207 				return (1);
208 		}
209 		F_SET(sp, SC_SCR_REDRAW);
210 	}
211 
212 	/*
213 	 * 6: Line movement.
214 	 *
215 	 * Line changes can cause the top line to change as well.  As
216 	 * before, if the movement is large, the screen is repainted.
217 	 *
218 	 * 6a: Small screens.
219 	 *
220 	 * Users can use the window, w300, w1200 and w9600 options to make
221 	 * the screen artificially small.  The behavior of these options
222 	 * in the historic vi wasn't all that consistent, and, in fact, it
223 	 * was never documented how various screen movements affected the
224 	 * screen size.  Generally, one of three things would happen:
225 	 *	1: The screen would expand in size, showing the line
226 	 *	2: The screen would scroll, showing the line
227 	 *	3: The screen would compress to its smallest size and
228 	 *		repaint.
229 	 * In general, scrolling didn't cause compression (200^D was handled
230 	 * the same as ^D), movement to a specific line would (:N where N
231 	 * was 1 line below the screen caused a screen compress), and cursor
232 	 * movement would scroll if it was 11 lines or less, and compress if
233 	 * it was more than 11 lines.  (And, no, I have no idea where the 11
234 	 * comes from.)
235 	 *
236 	 * What we do is try and figure out if the line is less than half of
237 	 * a full screen away.  If it is, we expand the screen if there's
238 	 * room, and then scroll as necessary.  The alternative is to compress
239 	 * and repaint.
240 	 *
241 	 * !!!
242 	 * This code is a special case from beginning to end.  Unfortunately,
243 	 * home modems are still slow enough that it's worth having.
244 	 *
245 	 * XXX
246 	 * If the line a really long one, i.e. part of the line is on the
247 	 * screen but the column offset is not, we'll end up in the adjust
248 	 * code, when we should probably have compressed the screen.
249 	 */
250 	if (IS_SMALL(sp)) {
251 		if (LNO < HMAP->lno) {
252 			lcnt = vs_sm_nlines(sp, HMAP, LNO, sp->t_maxrows);
253 			if (lcnt <= HALFSCREEN(sp))
254 				for (; lcnt && sp->t_rows != sp->t_maxrows;
255 				     --lcnt, ++sp->t_rows) {
256 					++TMAP;
257 					if (vs_sm_1down(sp))
258 						return (1);
259 				}
260 			else
261 				goto small_fill;
262 		} else if (LNO > TMAP->lno) {
263 			lcnt = vs_sm_nlines(sp, TMAP, LNO, sp->t_maxrows);
264 			if (lcnt <= HALFSCREEN(sp))
265 				for (; lcnt && sp->t_rows != sp->t_maxrows;
266 				     --lcnt, ++sp->t_rows) {
267 					if (vs_sm_next(sp, TMAP, TMAP + 1))
268 						return (1);
269 					++TMAP;
270 					if (vs_line(sp, TMAP, NULL, NULL))
271 						return (1);
272 				}
273 			else {
274 small_fill:			(void)gp->scr_move(sp, LASTLINE(sp), 0);
275 				(void)gp->scr_clrtoeol(sp);
276 				for (; sp->t_rows > sp->t_minrows;
277 				    --sp->t_rows, --TMAP) {
278 					(void)gp->scr_move(sp, TMAP - HMAP, 0);
279 					(void)gp->scr_clrtoeol(sp);
280 				}
281 				if (vs_sm_fill(sp, LNO, P_FILL))
282 					return (1);
283 				F_SET(sp, SC_SCR_REDRAW);
284 				goto adjust;
285 			}
286 		}
287 	}
288 
289 	/*
290 	 * 6b: Line down, or current screen.
291 	 */
292 	if (LNO >= HMAP->lno) {
293 		/* Current screen. */
294 		if (LNO <= TMAP->lno)
295 			goto adjust;
296 		if (F_ISSET(sp, SC_SCR_TOP))
297 			goto top;
298 		if (F_ISSET(sp, SC_SCR_CENTER))
299 			goto middle;
300 
301 		/*
302 		 * If less than half a screen above the line, scroll down
303 		 * until the line is on the screen.
304 		 */
305 		lcnt = vs_sm_nlines(sp, TMAP, LNO, HALFTEXT(sp));
306 		if (lcnt < HALFTEXT(sp)) {
307 			while (lcnt--)
308 				if (vs_sm_1up(sp))
309 					return (1);
310 			goto adjust;
311 		}
312 		goto bottom;
313 	}
314 
315 	/*
316 	 * 6c: If not on the current screen, may request center or top.
317 	 */
318 	if (F_ISSET(sp, SC_SCR_TOP))
319 		goto top;
320 	if (F_ISSET(sp, SC_SCR_CENTER))
321 		goto middle;
322 
323 	/*
324 	 * 6d: Line up.
325 	 */
326 	lcnt = vs_sm_nlines(sp, HMAP, LNO, HALFTEXT(sp));
327 	if (lcnt < HALFTEXT(sp)) {
328 		/*
329 		 * If less than half a screen below the line, scroll up until
330 		 * the line is the first line on the screen.  Special check so
331 		 * that if the screen has been emptied, we refill it.
332 		 */
333 		if (db_exist(sp, HMAP->lno)) {
334 			while (lcnt--)
335 				if (vs_sm_1down(sp))
336 					return (1);
337 			goto adjust;
338 		}
339 
340 		/*
341 		 * If less than a half screen from the bottom of the file,
342 		 * put the last line of the file on the bottom of the screen.
343 		 */
344 bottom:		if (db_last(sp, &lastline))
345 			return (1);
346 		tmp.lno = LNO;
347 		tmp.coff = HMAP->coff;
348 		tmp.soff = 1;
349 		lcnt = vs_sm_nlines(sp, &tmp, lastline, sp->t_rows);
350 		if (lcnt < HALFTEXT(sp)) {
351 			if (vs_sm_fill(sp, lastline, P_BOTTOM))
352 				return (1);
353 			F_SET(sp, SC_SCR_REDRAW);
354 			goto adjust;
355 		}
356 		/* It's not close, just put the line in the middle. */
357 		goto middle;
358 	}
359 
360 	/*
361 	 * If less than half a screen from the top of the file, put the first
362 	 * line of the file at the top of the screen.  Otherwise, put the line
363 	 * in the middle of the screen.
364 	 */
365 	tmp.lno = 1;
366 	tmp.coff = HMAP->coff;
367 	tmp.soff = 1;
368 	lcnt = vs_sm_nlines(sp, &tmp, LNO, HALFTEXT(sp));
369 	if (lcnt < HALFTEXT(sp)) {
370 		if (vs_sm_fill(sp, 1, P_TOP))
371 			return (1);
372 	} else
373 middle:		if (vs_sm_fill(sp, LNO, P_MIDDLE))
374 			return (1);
375 	if (0) {
376 top:		if (vs_sm_fill(sp, LNO, P_TOP))
377 			return (1);
378 	}
379 	F_SET(sp, SC_SCR_REDRAW);
380 
381 	/*
382 	 * At this point we know part of the line is on the screen.  Since
383 	 * scrolling is done using logical lines, not physical, all of the
384 	 * line may not be on the screen.  While that's not necessarily bad,
385 	 * if the part the cursor is on isn't there, we're going to lose.
386 	 * This can be tricky; if the line covers the entire screen, lno
387 	 * may be the same as both ends of the map, that's why we test BOTH
388 	 * the top and the bottom of the map.  This isn't a problem for
389 	 * left-right scrolling, the cursor movement code handles the problem.
390 	 *
391 	 * There's a performance issue here if editing *really* long lines.
392 	 * This gets to the right spot by scrolling, and, in a binary, by
393 	 * scrolling hundreds of lines.  If the adjustment looks like it's
394 	 * going to be a serious problem, refill the screen and repaint.
395 	 */
396 adjust:	if (!O_ISSET(sp, O_LEFTRIGHT) &&
397 	    (LNO == HMAP->lno || LNO == TMAP->lno)) {
398 		cnt = vs_screens(sp, LNO, &CNO);
399 		if (LNO == HMAP->lno && cnt < HMAP->soff) {
400 			if ((HMAP->soff - cnt) > HALFTEXT(sp)) {
401 				HMAP->soff = cnt;
402 				vs_sm_fill(sp, OOBLNO, P_TOP);
403 				F_SET(sp, SC_SCR_REDRAW);
404 			} else
405 				while (cnt < HMAP->soff)
406 					if (vs_sm_1down(sp))
407 						return (1);
408 		}
409 		if (LNO == TMAP->lno && cnt > TMAP->soff) {
410 			if ((cnt - TMAP->soff) > HALFTEXT(sp)) {
411 				TMAP->soff = cnt;
412 				vs_sm_fill(sp, OOBLNO, P_BOTTOM);
413 				F_SET(sp, SC_SCR_REDRAW);
414 			} else
415 				while (cnt > TMAP->soff)
416 					if (vs_sm_1up(sp))
417 						return (1);
418 		}
419 	}
420 
421 	/*
422 	 * If the screen needs to be repainted, skip cursor optimization.
423 	 * However, in the code above we skipped leftright scrolling on
424 	 * the grounds that the cursor code would handle it.  Make sure
425 	 * the right screen is up.
426 	 */
427 	if (F_ISSET(sp, SC_SCR_REDRAW)) {
428 		if (O_ISSET(sp, O_LEFTRIGHT))
429 			goto slow;
430 		goto paint;
431 	}
432 
433 	/*
434 	 * 7: Cursor movements (current screen only).
435 	 */
436 	if (!LF_ISSET(UPDATE_CURSOR))
437 		goto number;
438 
439 	/*
440 	 * Decide cursor position.  If the line has changed, the cursor has
441 	 * moved over a tab, or don't know where the cursor was, reparse the
442 	 * line.  Otherwise, we've just moved over fixed-width characters,
443 	 * and can calculate the left/right scrolling and cursor movement
444 	 * without reparsing the line.  Note that we don't know which (if any)
445 	 * of the characters between the old and new cursor positions changed.
446 	 *
447 	 * XXX
448 	 * With some work, it should be possible to handle tabs quickly, at
449 	 * least in obvious situations, like moving right and encountering
450 	 * a tab, without reparsing the whole line.
451 	 *
452 	 * If the line we're working with has changed, reread it..
453 	 */
454 	if (F_ISSET(vip, VIP_CUR_INVALID) || LNO != OLNO)
455 		goto slow;
456 
457 	/* Otherwise, if nothing's changed, ignore the cursor. */
458 	if (CNO == OCNO)
459 		goto fast;
460 
461 	/*
462 	 * Get the current line.  If this fails, we either have an empty
463 	 * file and can just repaint, or there's a real problem.  This
464 	 * isn't a performance issue because there aren't any ways to get
465 	 * here repeatedly.
466 	 */
467 	if (db_eget(sp, LNO, &p, &len, &isempty)) {
468 		if (isempty)
469 			goto slow;
470 		return (1);
471 	}
472 
473 #ifdef DEBUG
474 	/* Sanity checking. */
475 	if (CNO >= len && len != 0) {
476 		msgq(sp, M_ERR, "Error: %s/%d: cno (%u) >= len (%u)",
477 		     basename(__FILE__), __LINE__, CNO, len);
478 		return (1);
479 	}
480 #endif
481 	/*
482 	 * The basic scheme here is to look at the characters in between
483 	 * the old and new positions and decide how big they are on the
484 	 * screen, and therefore, how many screen positions to move.
485 	 */
486 	if (CNO < OCNO) {
487 		/*
488 		 * 7a: Cursor moved left.
489 		 *
490 		 * Point to the old character.  The old cursor position can
491 		 * be past EOL if, for example, we just deleted the rest of
492 		 * the line.  In this case, since we don't know the width of
493 		 * the characters we traversed, we have to do it slowly.
494 		 */
495 		p += OCNO;
496 		cnt = (OCNO - CNO) + 1;
497 		if (OCNO >= len)
498 			goto slow;
499 
500 		/*
501 		 * Quick sanity check -- it's hard to figure out exactly when
502 		 * we cross a screen boundary as we do in the cursor right
503 		 * movement.  If cnt is so large that we're going to cross the
504 		 * boundary no matter what, stop now.
505 		 */
506 		if (SCNO + 1 + MAX_CHARACTER_COLUMNS < cnt)
507 			goto slow;
508 
509 		/*
510 		 * Count up the widths of the characters.  If it's a tab
511 		 * character, go do it the slow way.
512 		 */
513 		for (cwtotal = 0; cnt--; cwtotal += KEY_LEN(sp, ch))
514 			if ((ch = *(u_char *)p--) == '\t')
515 				goto slow;
516 
517 		/*
518 		 * Decrement the screen cursor by the total width of the
519 		 * characters minus 1.
520 		 */
521 		cwtotal -= 1;
522 
523 		/*
524 		 * If we're moving left, and there's a wide character in the
525 		 * current position, go to the end of the character.
526 		 */
527 		if (KEY_LEN(sp, ch) > 1)
528 			cwtotal -= KEY_LEN(sp, ch) - 1;
529 
530 		/*
531 		 * If the new column moved us off of the current logical line,
532 		 * calculate a new one.  If doing leftright scrolling, we've
533 		 * moved off of the current screen, as well.
534 		 */
535 		if (SCNO < cwtotal)
536 			goto slow;
537 		SCNO -= cwtotal;
538 	} else {
539 		/*
540 		 * 7b: Cursor moved right.
541 		 *
542 		 * Point to the first character to the right.
543 		 */
544 		p += OCNO + 1;
545 		cnt = CNO - OCNO;
546 
547 		/*
548 		 * Count up the widths of the characters.  If it's a tab
549 		 * character, go do it the slow way.  If we cross a
550 		 * screen boundary, we can quit.
551 		 */
552 		for (cwtotal = SCNO; cnt--;) {
553 			if ((ch = *(u_char *)p++) == '\t')
554 				goto slow;
555 			if ((cwtotal += KEY_LEN(sp, ch)) >= SCREEN_COLS(sp))
556 				break;
557 		}
558 
559 		/*
560 		 * Increment the screen cursor by the total width of the
561 		 * characters.
562 		 */
563 		SCNO = cwtotal;
564 
565 		/* See screen change comment in section 6a. */
566 		if (SCNO >= SCREEN_COLS(sp))
567 			goto slow;
568 	}
569 
570 	/*
571 	 * 7c: Fast cursor update.
572 	 *
573 	 * We have the current column, retrieve the current row.
574 	 */
575 fast:	(void)gp->scr_cursor(sp, &y, &notused);
576 	goto done_cursor;
577 
578 	/*
579 	 * 7d: Slow cursor update.
580 	 *
581 	 * Walk through the map and find the current line.
582 	 */
583 slow:	for (smp = HMAP; smp->lno != LNO; ++smp);
584 
585 	/*
586 	 * 7e: Leftright scrolling adjustment.
587 	 *
588 	 * If doing left-right scrolling and the cursor movement has changed
589 	 * the displayed screen, scroll the screen left or right, unless we're
590 	 * updating the info line in which case we just scroll that one line.
591 	 * We adjust the offset up or down until we have a window that covers
592 	 * the current column, making sure that we adjust differently for the
593 	 * first screen as compared to subsequent ones.
594 	 */
595 	if (O_ISSET(sp, O_LEFTRIGHT)) {
596 		/*
597 		 * Get the screen column for this character, and correct
598 		 * for the number option offset.
599 		 */
600 		cnt = vs_columns(sp, NULL, LNO, &CNO, NULL);
601 		if (O_ISSET(sp, O_NUMBER))
602 			cnt -= O_NUMBER_LENGTH;
603 
604 		/* Adjust the window towards the beginning of the line. */
605 		off = smp->coff;
606 		if (off >= cnt) {
607 			do {
608 				if (off >= O_VAL(sp, O_SIDESCROLL))
609 					off -= O_VAL(sp, O_SIDESCROLL);
610 				else {
611 					off = 0;
612 					break;
613 				}
614 			} while (off >= cnt);
615 			goto shifted;
616 		}
617 
618 		/* Adjust the window towards the end of the line. */
619 		if ((off == 0 && off + SCREEN_COLS(sp) < cnt) ||
620 		    (off != 0 && off + sp->cols < cnt)) {
621 			do {
622 				off += O_VAL(sp, O_SIDESCROLL);
623 			} while (off + sp->cols < cnt);
624 
625 shifted:		/* Fill in screen map with the new offset. */
626 			if (F_ISSET(sp, SC_TINPUT_INFO))
627 				smp->coff = off;
628 			else {
629 				for (smp = HMAP; smp <= TMAP; ++smp)
630 					smp->coff = off;
631 				leftright_warp = 1;
632 			}
633 			goto paint;
634 		}
635 
636 		/*
637 		 * We may have jumped here to adjust a leftright screen because
638 		 * redraw was set.  If so, we have to paint the entire screen.
639 		 */
640 		if (F_ISSET(sp, SC_SCR_REDRAW))
641 			goto paint;
642 	}
643 
644 	/*
645 	 * Update the screen lines for this particular file line until we
646 	 * have a new screen cursor position.
647 	 */
648 	for (y = -1,
649 	    vip->sc_smap = NULL; smp <= TMAP && smp->lno == LNO; ++smp) {
650 		if (vs_line(sp, smp, &y, &SCNO))
651 			return (1);
652 		if (y != -1) {
653 			vip->sc_smap = smp;
654 			break;
655 		}
656 	}
657 	goto done_cursor;
658 
659 	/*
660 	 * 8: Repaint the entire screen.
661 	 *
662 	 * Lost big, do what you have to do.  We flush the cache, since
663 	 * SC_SCR_REDRAW gets set when the screen isn't worth fixing, and
664 	 * it's simpler to repaint.  So, don't trust anything that we
665 	 * think we know about it.
666 	 */
667 paint:	for (smp = HMAP; smp <= TMAP; ++smp)
668 		SMAP_FLUSH(smp);
669 	for (y = -1, vip->sc_smap = NULL, smp = HMAP; smp <= TMAP; ++smp) {
670 		if (vs_line(sp, smp, &y, &SCNO))
671 			return (1);
672 		if (y != -1 && vip->sc_smap == NULL)
673 			vip->sc_smap = smp;
674 	}
675 	/*
676 	 * If it's a small screen and we're redrawing, clear the unused lines,
677 	 * ex may have overwritten them.
678 	 */
679 	if (F_ISSET(sp, SC_SCR_REDRAW) && IS_SMALL(sp))
680 		for (cnt = sp->t_rows; cnt <= sp->t_maxrows; ++cnt) {
681 			(void)gp->scr_move(sp, cnt, 0);
682 			(void)gp->scr_clrtoeol(sp);
683 		}
684 
685 	didpaint = 1;
686 
687 done_cursor:
688 	/*
689 	 * Sanity checking.  When the repainting code messes up, the usual
690 	 * result is we don't repaint the cursor and so sc_smap will be
691 	 * NULL.  If we're debugging, die, otherwise restart from scratch.
692 	 */
693 #ifdef DEBUG
694 	if (vip->sc_smap == NULL)
695 		abort();
696 #else
697 	if (vip->sc_smap == NULL) {
698 		if (F_ISSET(sp, SC_SCR_REFORMAT))
699 			return (0);
700 		F_SET(sp, SC_SCR_REFORMAT);
701 		return (vs_paint(sp, flags));
702 	}
703 #endif
704 
705 	/*
706 	 * 9: Set the remembered cursor values.
707 	 */
708 	OCNO = CNO;
709 	OLNO = LNO;
710 
711 	/*
712 	 * 10: Repaint the line numbers.
713 	 *
714 	 * If O_NUMBER is set and the VIP_N_RENUMBER bit is set, and we
715 	 * didn't repaint the screen, repaint all of the line numbers,
716 	 * they've changed.
717 	 */
718 number:	if (O_ISSET(sp, O_NUMBER) &&
719 	    F_ISSET(vip, VIP_N_RENUMBER) && !didpaint && vs_number(sp))
720 		return (1);
721 
722 	/*
723 	 * 11: Update the mode line, position the cursor, and flush changes.
724 	 *
725 	 * If we warped the screen, we have to refresh everything.
726 	 */
727 	if (leftright_warp)
728 		LF_SET(UPDATE_CURSOR | UPDATE_SCREEN);
729 
730 	if (LF_ISSET(UPDATE_SCREEN) && !IS_ONELINE(sp) &&
731 	    !F_ISSET(vip, VIP_S_MODELINE) && !F_ISSET(sp, SC_TINPUT_INFO))
732 		vs_modeline(sp);
733 
734 	if (LF_ISSET(UPDATE_CURSOR)) {
735 		(void)gp->scr_move(sp, y, SCNO);
736 
737 		/*
738 		 * XXX
739 		 * If the screen shifted, we recalculate the "most favorite"
740 		 * cursor position.  Vi won't know that we've warped the
741 		 * screen, so it's going to have a wrong idea about where the
742 		 * cursor should be.  This is vi's problem, and fixing it here
743 		 * is a gross layering violation.
744 		 */
745 		if (leftright_warp)
746 			(void)vs_column(sp, &sp->rcm);
747 	}
748 
749 	if (LF_ISSET(UPDATE_SCREEN))
750 		(void)gp->scr_refresh(sp, F_ISSET(vip, VIP_N_EX_PAINT));
751 
752 	/* 12: Clear the flags that are handled by this routine. */
753 	F_CLR(sp, SC_SCR_CENTER | SC_SCR_REDRAW | SC_SCR_REFORMAT | SC_SCR_TOP);
754 	F_CLR(vip, VIP_CUR_INVALID |
755 	    VIP_N_EX_PAINT | VIP_N_REFRESH | VIP_N_RENUMBER | VIP_S_MODELINE);
756 
757 	return (0);
758 
759 #undef	 LNO
760 #undef	OLNO
761 #undef	 CNO
762 #undef	OCNO
763 #undef	SCNO
764 }
765 
766 /*
767  * vs_modeline --
768  *	Update the mode line.
769  */
770 static void
vs_modeline(SCR * sp)771 vs_modeline(SCR *sp)
772 {
773 	static char * const modes[] = {
774 		"Append",			/* SM_APPEND */
775 		"Change",			/* SM_CHANGE */
776 		"Command",			/* SM_COMMAND */
777 		"Insert",			/* SM_INSERT */
778 		"Replace",			/* SM_REPLACE */
779 	};
780 	GS *gp;
781 	size_t cols, curcol, curlen, endpoint, len, midpoint;
782 	const char *t = NULL;
783 	int ellipsis;
784 	char *p, buf[30];
785 	recno_t last;
786 
787 	/*
788 	 * It's possible that this routine will be called after sp->frp
789 	 * has been set to NULL by file_end().  We return immediately
790 	 * to avoid a SEGV.
791 	 */
792 	if (sp->frp == NULL)
793 		return;
794 
795 	gp = sp->gp;
796 
797 	/*
798 	 * We put down the file name, the ruler, the mode and the dirty flag.
799 	 * If there's not enough room, there's not enough room, we don't play
800 	 * any special games.  We try to put the ruler in the middle and the
801 	 * mode and dirty flag at the end.
802 	 *
803 	 * !!!
804 	 * Leave the last character blank, in case it's a really dumb terminal
805 	 * with hardware scroll.  Second, don't paint the last character in the
806 	 * screen, SunOS 4.1.1 and Ultrix 4.2 curses won't let you.
807 	 *
808 	 * Move to the last line on the screen.
809 	 */
810 	(void)gp->scr_move(sp, LASTLINE(sp), 0);
811 
812 	/* If more than one screen in the display, show the file name. */
813 	curlen = 0;
814 	if (IS_SPLIT(sp) || O_ISSET(sp, O_SHOWFILENAME)) {
815 		for (p = sp->frp->name; *p != '\0'; ++p);
816 		for (ellipsis = 0, cols = sp->cols / 2; --p > sp->frp->name;) {
817 			if (*p == '/') {
818 				++p;
819 				break;
820 			}
821 			if ((curlen += KEY_LEN(sp, *p)) > cols) {
822 				ellipsis = 3;
823 				curlen +=
824 				    KEY_LEN(sp, '.') * 3 + KEY_LEN(sp, ' ');
825 				while (curlen > cols) {
826 					++p;
827 					curlen -= KEY_LEN(sp, *p);
828 				}
829 				break;
830 			}
831 		}
832 		if (ellipsis) {
833 			while (ellipsis--)
834 				(void)gp->scr_addstr(sp,
835 				    KEY_NAME(sp, '.'), KEY_LEN(sp, '.'));
836 			(void)gp->scr_addstr(sp,
837 			    KEY_NAME(sp, ' '), KEY_LEN(sp, ' '));
838 		}
839 		for (; *p != '\0'; ++p)
840 			(void)gp->scr_addstr(sp,
841 			    KEY_NAME(sp, *p), KEY_LEN(sp, *p));
842 	}
843 
844 	/* Clear the rest of the line. */
845 	(void)gp->scr_clrtoeol(sp);
846 
847 	/*
848 	 * Display the ruler.  If we're not at the midpoint yet, move there.
849 	 * Otherwise, add in two extra spaces.
850 	 *
851 	 * Adjust the current column for the fact that the editor uses it as
852 	 * a zero-based number.
853 	 *
854 	 * XXX
855 	 * Assume that numbers, commas, and spaces only take up a single
856 	 * column on the screen.
857 	 */
858 	cols = sp->cols - 1;
859 	if (O_ISSET(sp, O_RULER)) {
860 		vs_column(sp, &curcol);
861 
862 		if (db_last(sp, &last) || last == 0)
863 			len = snprintf(buf, sizeof(buf), "%lu,%zu",
864 			    (ulong)sp->lno, curcol + 1);
865 		else
866 			len = snprintf(buf, sizeof(buf), "%lu,%zu %lu%%",
867 			    (ulong)sp->lno, curcol + 1,
868 			    (unsigned long)(sp->lno * 100) / last);
869 
870 		midpoint = (cols - ((len + 1) / 2)) / 2;
871 		if (curlen < midpoint) {
872 			(void)gp->scr_move(sp, LASTLINE(sp), midpoint);
873 			curlen += len;
874 		} else if (curlen + 2 + len < cols) {
875 			(void)gp->scr_addstr(sp, "  ", 2);
876 			curlen += 2 + len;
877 		}
878 		(void)gp->scr_addstr(sp, buf, len);
879 	}
880 
881 	/*
882 	 * Display the mode and the modified flag, as close to the end of the
883 	 * line as possible, but guaranteeing at least two spaces between the
884 	 * ruler and the modified flag.
885 	 */
886 #define	MODESIZE	9
887 	endpoint = cols;
888 	if (O_ISSET(sp, O_SHOWMODE)) {
889 		if (F_ISSET(sp->ep, F_MODIFIED))
890 			--endpoint;
891 		t = modes[sp->showmode];
892 		endpoint -= (len = strlen(t));
893 	}
894 
895 	if (endpoint > curlen + 2) {
896 		(void)gp->scr_move(sp, LASTLINE(sp), endpoint);
897 		if (O_ISSET(sp, O_SHOWMODE)) {
898 			if (F_ISSET(sp->ep, F_MODIFIED))
899 				(void)gp->scr_addstr(sp,
900 				    KEY_NAME(sp, '*'), KEY_LEN(sp, '*'));
901 			(void)gp->scr_addstr(sp, t, len);
902 		}
903 	}
904 }
905