xref: /freebsd/contrib/nvi/vi/vs_line.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "$Id: vs_line.c,v 10.40 2012/02/13 19:22:25 zy Exp $";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/time.h>
19 
20 #include <bitstring.h>
21 #include <limits.h>
22 #include <stdio.h>
23 #include <string.h>
24 
25 #include "../common/common.h"
26 #include "vi.h"
27 
28 #ifdef VISIBLE_TAB_CHARS
29 #define	TABCH	'-'
30 #else
31 #define	TABCH	' '
32 #endif
33 
34 /*
35  * vs_line --
36  *	Update one line on the screen.
37  *
38  * PUBLIC: int vs_line(SCR *, SMAP *, size_t *, size_t *);
39  */
40 int
41 vs_line(SCR *sp, SMAP *smp, size_t *yp, size_t *xp)
42 {
43 	u_char *kp;
44 	GS *gp;
45 	SMAP *tsmp;
46 	size_t chlen = 0, cno_cnt, cols_per_screen, len, nlen;
47 	size_t offset_in_char, offset_in_line, oldx, oldy;
48 	size_t scno, skip_cols, skip_screens;
49 	int dne, is_cached, is_partial, is_tab, no_draw;
50 	int list_tab, list_dollar;
51 	CHAR_T *p;
52 	CHAR_T *cbp, *ecbp, cbuf[128];
53 	ARG_CHAR_T ch = '\0';
54 
55 #if defined(DEBUG) && 0
56 	TRACE(sp, "vs_line: row %u: line: %u off: %u\n",
57 	    smp - HMAP, smp->lno, smp->off);
58 #endif
59 	/*
60 	 * If ex modifies the screen after ex output is already on the screen,
61 	 * don't touch it -- we'll get scrolling wrong, at best.
62 	 */
63 	no_draw = 0;
64 	if (!F_ISSET(sp, SC_TINPUT_INFO) && VIP(sp)->totalcount > 1)
65 		no_draw = 1;
66 	if (F_ISSET(sp, SC_SCR_EXWROTE) && smp - HMAP != LASTLINE(sp))
67 		no_draw = 1;
68 
69 	/*
70 	 * Assume that, if the cache entry for the line is filled in, the
71 	 * line is already on the screen, and all we need to do is return
72 	 * the cursor position.  If the calling routine doesn't need the
73 	 * cursor position, we can just return.
74 	 */
75 	is_cached = SMAP_CACHE(smp);
76 	if (yp == NULL && (is_cached || no_draw))
77 		return (0);
78 
79 	/*
80 	 * A nasty side effect of this routine is that it returns the screen
81 	 * position for the "current" character.  Not pretty, but this is the
82 	 * only routine that really knows what's out there.
83 	 *
84 	 * Move to the line.  This routine can be called by vs_sm_position(),
85 	 * which uses it to fill in the cache entry so it can figure out what
86 	 * the real contents of the screen are.  Because of this, we have to
87 	 * return to whereever we started from.
88 	 */
89 	gp = sp->gp;
90 	(void)gp->scr_cursor(sp, &oldy, &oldx);
91 	(void)gp->scr_move(sp, smp - HMAP, 0);
92 
93 	/* Get the line. */
94 	dne = db_get(sp, smp->lno, 0, &p, &len);
95 
96 	/*
97 	 * Special case if we're printing the info/mode line.  Skip printing
98 	 * the leading number, as well as other minor setup.  The only time
99 	 * this code paints the mode line is when the user is entering text
100 	 * for a ":" command, so we can put the code here instead of dealing
101 	 * with the empty line logic below.  This is a kludge, but it's pretty
102 	 * much confined to this module.
103 	 *
104 	 * Set the number of columns for this screen.
105 	 * Set the number of chars or screens to skip until a character is to
106 	 * be displayed.
107 	 */
108 	cols_per_screen = sp->cols;
109 	if (O_ISSET(sp, O_LEFTRIGHT)) {
110 		skip_screens = 0;
111 		skip_cols = smp->coff;
112 	} else {
113 		skip_screens = smp->soff - 1;
114 		skip_cols = skip_screens * cols_per_screen;
115 	}
116 
117 	list_tab = O_ISSET(sp, O_LIST);
118 	if (F_ISSET(sp, SC_TINPUT_INFO))
119 		list_dollar = 0;
120 	else {
121 		list_dollar = list_tab;
122 
123 		/*
124 		 * If O_NUMBER is set, the line doesn't exist and it's line
125 		 * number 1, i.e., an empty file, display the line number.
126 		 *
127 		 * If O_NUMBER is set, the line exists and the first character
128 		 * on the screen is the first character in the line, display
129 		 * the line number.
130 		 *
131 		 * !!!
132 		 * If O_NUMBER set, decrement the number of columns in the
133 		 * first screen.  DO NOT CHANGE THIS -- IT'S RIGHT!  The
134 		 * rest of the code expects this to reflect the number of
135 		 * columns in the first screen, regardless of the number of
136 		 * columns we're going to skip.
137 		 */
138 		if (O_ISSET(sp, O_NUMBER)) {
139 			cols_per_screen -= O_NUMBER_LENGTH;
140 			if ((!dne || smp->lno == 1) && skip_cols == 0) {
141 				nlen = snprintf((char*)cbuf,
142 				    sizeof(cbuf), O_NUMBER_FMT, (u_long)smp->lno);
143 				(void)gp->scr_addstr(sp, (char*)cbuf, nlen);
144 			}
145 		}
146 	}
147 
148 	/*
149 	 * Special case non-existent lines and the first line of an empty
150 	 * file.  In both cases, the cursor position is 0, but corrected
151 	 * as necessary for the O_NUMBER field, if it was displayed.
152 	 */
153 	if (dne || len == 0) {
154 		/* Fill in the cursor. */
155 		if (yp != NULL && smp->lno == sp->lno) {
156 			*yp = smp - HMAP;
157 			*xp = sp->cols - cols_per_screen;
158 		}
159 
160 		/* If the line is on the screen, quit. */
161 		if (is_cached || no_draw)
162 			goto ret1;
163 
164 		/* Set line cache information. */
165 		smp->c_sboff = smp->c_eboff = 0;
166 		smp->c_scoff = smp->c_eclen = 0;
167 
168 		/*
169 		 * Lots of special cases for empty lines, but they only apply
170 		 * if we're displaying the first screen of the line.
171 		 */
172 		if (skip_cols == 0)
173 			if (dne) {
174 				if (smp->lno == 1) {
175 					if (list_dollar) {
176 						ch = '$';
177 						goto empty;
178 					}
179 				} else {
180 					ch = '~';
181 					goto empty;
182 				}
183 			} else
184 				if (list_dollar) {
185 					ch = '$';
186 empty:					(void)gp->scr_addstr(sp,
187 					    KEY_NAME(sp, ch), KEY_LEN(sp, ch));
188 				}
189 
190 		(void)gp->scr_clrtoeol(sp);
191 		(void)gp->scr_move(sp, oldy, oldx);
192 		return (0);
193 	}
194 
195 	/* If we shortened this line in another screen, the cursor
196 	 * position may have fallen off.
197 	 */
198 	if (sp->lno == smp->lno && sp->cno >= len)
199 	    sp->cno = len - 1;
200 
201 	/*
202 	 * If we just wrote this or a previous line, we cached the starting
203 	 * and ending positions of that line.  The way it works is we keep
204 	 * information about the lines displayed in the SMAP.  If we're
205 	 * painting the screen in the forward direction, this saves us from
206 	 * reformatting the physical line for every line on the screen.  This
207 	 * wins big on binary files with 10K lines.
208 	 *
209 	 * Test for the first screen of the line, then the current screen line,
210 	 * then the line behind us, then do the hard work.  Note, it doesn't
211 	 * do us any good to have a line in front of us -- it would be really
212 	 * hard to try and figure out tabs in the reverse direction, i.e. how
213 	 * many spaces a tab takes up in the reverse direction depends on
214 	 * what characters preceded it.
215 	 *
216 	 * Test for the first screen of the line.
217 	 */
218 	if (skip_cols == 0) {
219 		smp->c_sboff = offset_in_line = 0;
220 		smp->c_scoff = offset_in_char = 0;
221 		p = &p[offset_in_line];
222 		goto display;
223 	}
224 
225 	/* Test to see if we've seen this exact line before. */
226 	if (is_cached) {
227 		offset_in_line = smp->c_sboff;
228 		offset_in_char = smp->c_scoff;
229 		p = &p[offset_in_line];
230 
231 		/* Set cols_per_screen to 2nd and later line length. */
232 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
233 			cols_per_screen = sp->cols;
234 		goto display;
235 	}
236 
237 	/* Test to see if we saw an earlier part of this line before. */
238 	if (smp != HMAP &&
239 	    SMAP_CACHE(tsmp = smp - 1) && tsmp->lno == smp->lno) {
240 		if (tsmp->c_eclen != tsmp->c_ecsize) {
241 			offset_in_line = tsmp->c_eboff;
242 			offset_in_char = tsmp->c_eclen;
243 		} else {
244 			offset_in_line = tsmp->c_eboff + 1;
245 			offset_in_char = 0;
246 		}
247 
248 		/* Put starting info for this line in the cache. */
249 		smp->c_sboff = offset_in_line;
250 		smp->c_scoff = offset_in_char;
251 		p = &p[offset_in_line];
252 
253 		/* Set cols_per_screen to 2nd and later line length. */
254 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
255 			cols_per_screen = sp->cols;
256 		goto display;
257 	}
258 
259 	scno = 0;
260 	offset_in_line = 0;
261 	offset_in_char = 0;
262 
263 	/* Do it the hard way, for leftright scrolling screens. */
264 	if (O_ISSET(sp, O_LEFTRIGHT)) {
265 		for (; offset_in_line < len; ++offset_in_line) {
266 			chlen = (ch = *p++) == '\t' && !list_tab ?
267 			    TAB_OFF(scno) : KEY_COL(sp, ch);
268 			if ((scno += chlen) >= skip_cols)
269 				break;
270 		}
271 
272 		/* Set cols_per_screen to 2nd and later line length. */
273 		cols_per_screen = sp->cols;
274 
275 		/* Put starting info for this line in the cache. */
276 		if (offset_in_line >= len) {
277 			smp->c_sboff = offset_in_line;
278 			smp->c_scoff = 255;
279 		} else if (scno != skip_cols) {
280 			smp->c_sboff = offset_in_line;
281 			smp->c_scoff =
282 			    offset_in_char = chlen - (scno - skip_cols);
283 			--p;
284 		} else {
285 			smp->c_sboff = ++offset_in_line;
286 			smp->c_scoff = 0;
287 		}
288 	}
289 
290 	/* Do it the hard way, for historic line-folding screens. */
291 	else {
292 		for (; offset_in_line < len; ++offset_in_line) {
293 			chlen = (ch = *p++) == '\t' && !list_tab ?
294 			    TAB_OFF(scno) : KEY_COL(sp, ch);
295 			if ((scno += chlen) < cols_per_screen)
296 				continue;
297 			scno -= cols_per_screen;
298 
299 			/* Set cols_per_screen to 2nd and later line length. */
300 			cols_per_screen = sp->cols;
301 
302 			/*
303 			 * If crossed the last skipped screen boundary, start
304 			 * displaying the characters.
305 			 */
306 			if (--skip_screens == 0)
307 				break;
308 		}
309 
310 		/* Put starting info for this line in the cache. */
311 		if (scno != 0) {
312 			smp->c_sboff = offset_in_line;
313 			smp->c_scoff = offset_in_char = chlen - scno;
314 			--p;
315 		} else {
316 			smp->c_sboff = ++offset_in_line;
317 			smp->c_scoff = 0;
318 		}
319 	}
320 
321 display:
322 	/*
323 	 * Set the number of characters to skip before reaching the cursor
324 	 * character.  Offset by 1 and use 0 as a flag value.  Vs_line is
325 	 * called repeatedly with a valid pointer to a cursor position.
326 	 * Don't fill anything in unless it's the right line and the right
327 	 * character, and the right part of the character...
328 	 */
329 	if (yp == NULL ||
330 	    smp->lno != sp->lno || sp->cno < offset_in_line ||
331 	    offset_in_line + cols_per_screen < sp->cno) {
332 		cno_cnt = 0;
333 		/* If the line is on the screen, quit. */
334 		if (is_cached || no_draw)
335 			goto ret1;
336 	} else
337 		cno_cnt = (sp->cno - offset_in_line) + 1;
338 
339 	/* This is the loop that actually displays characters. */
340 	ecbp = (cbp = cbuf) + SIZE(cbuf) - 1;
341 	for (is_partial = 0, scno = 0;
342 	    offset_in_line < len; ++offset_in_line, offset_in_char = 0) {
343 		if ((ch = *p++) == '\t' && !list_tab) {
344 			scno += chlen = TAB_OFF(scno) - offset_in_char;
345 			is_tab = 1;
346 		} else {
347 			scno += chlen = KEY_COL(sp, ch) - offset_in_char;
348 			is_tab = 0;
349 		}
350 
351 		/*
352 		 * Only display up to the right-hand column.  Set a flag if
353 		 * the entire character wasn't displayed for use in setting
354 		 * the cursor.  If reached the end of the line, set the cache
355 		 * info for the screen.  Don't worry about there not being
356 		 * characters to display on the next screen, its lno/off won't
357 		 * match up in that case.
358 		 */
359 		if (scno >= cols_per_screen) {
360 			if (is_tab == 1) {
361 				chlen -= scno - cols_per_screen;
362 				smp->c_ecsize = smp->c_eclen = chlen;
363 				scno = cols_per_screen;
364 			} else {
365 				smp->c_ecsize = chlen;
366 				chlen -= scno - cols_per_screen;
367 				smp->c_eclen = chlen;
368 
369 				if (scno > cols_per_screen)
370 					is_partial = 1;
371 			}
372 			smp->c_eboff = offset_in_line;
373 
374 			/* Terminate the loop. */
375 			offset_in_line = len;
376 		}
377 
378 		/*
379 		 * If the caller wants the cursor value, and this was the
380 		 * cursor character, set the value.  There are two ways to
381 		 * put the cursor on a character -- if it's normal display
382 		 * mode, it goes on the last column of the character.  If
383 		 * it's input mode, it goes on the first.  In normal mode,
384 		 * set the cursor only if the entire character was displayed.
385 		 */
386 		if (cno_cnt &&
387 		    --cno_cnt == 0 && (F_ISSET(sp, SC_TINPUT) || !is_partial)) {
388 			*yp = smp - HMAP;
389 			if (F_ISSET(sp, SC_TINPUT))
390 				if (is_partial)
391 					*xp = scno - smp->c_ecsize;
392 				else
393 					*xp = scno - chlen;
394 			else
395 				*xp = scno - 1;
396 			if (O_ISSET(sp, O_NUMBER) &&
397 			    !F_ISSET(sp, SC_TINPUT_INFO) && skip_cols == 0)
398 				*xp += O_NUMBER_LENGTH;
399 
400 			/* If the line is on the screen, quit. */
401 			if (is_cached || no_draw)
402 				goto ret1;
403 		}
404 
405 		/* If the line is on the screen, don't display anything. */
406 		if (is_cached || no_draw)
407 			continue;
408 
409 #define	FLUSH {								\
410 	*cbp = '\0';							\
411 	(void)gp->scr_waddstr(sp, cbuf, cbp - cbuf);			\
412 	cbp = cbuf;							\
413 }
414 		/*
415 		 * Display the character.  We do tab expansion here because
416 		 * the screen interface doesn't have any way to set the tab
417 		 * length.  Note, it's theoretically possible for chlen to
418 		 * be larger than cbuf, if the user set a impossibly large
419 		 * tabstop.
420 		 */
421 		if (is_tab)
422 			while (chlen--) {
423 				if (cbp >= ecbp)
424 					FLUSH;
425 				*cbp++ = TABCH;
426 			}
427 		else {
428 			if (cbp + chlen >= ecbp)
429 				FLUSH;
430 
431 			/* don't display half a wide character */
432 			if (is_partial && CHAR_WIDTH(sp, ch) > 1) {
433 				*cbp++ = ' ';
434 				break;
435 			}
436 
437 			if (KEY_NEEDSWIDE(sp, ch))
438 				*cbp++ = ch;
439 			else
440 				for (kp = (u_char *)
441 				    KEY_NAME(sp, ch) + offset_in_char;
442 				    chlen--;)
443 					*cbp++ = *kp++;
444 		}
445 	}
446 
447 	if (scno < cols_per_screen) {
448 		/* If didn't paint the whole line, update the cache. */
449 		smp->c_ecsize = smp->c_eclen = KEY_COL(sp, ch);
450 		smp->c_eboff = len - 1;
451 
452 		/*
453 		 * If not the info/mode line, and O_LIST set, and at the
454 		 * end of the line, and the line ended on this screen,
455 		 * add a trailing $.
456 		 */
457 		if (list_dollar) {
458 			++scno;
459 
460 			chlen = KEY_LEN(sp, '$');
461 			if (cbp + chlen >= ecbp)
462 				FLUSH;
463 			for (kp = (u_char *)
464 			    KEY_NAME(sp, '$'); chlen--;)
465 				*cbp++ = *kp++;
466 		}
467 
468 		/* If still didn't paint the whole line, clear the rest. */
469 		if (scno < cols_per_screen)
470 			(void)gp->scr_clrtoeol(sp);
471 	}
472 
473 	/* Flush any buffered characters. */
474 	if (cbp > cbuf)
475 		FLUSH;
476 
477 ret1:	(void)gp->scr_move(sp, oldy, oldx);
478 	return (0);
479 }
480 
481 /*
482  * vs_number --
483  *	Repaint the numbers on all the lines.
484  *
485  * PUBLIC: int vs_number(SCR *);
486  */
487 int
488 vs_number(SCR *sp)
489 {
490 	GS *gp;
491 	SMAP *smp;
492 	VI_PRIVATE *vip;
493 	size_t len, oldy, oldx;
494 	int exist;
495 	char nbuf[10];
496 
497 	gp = sp->gp;
498 	vip = VIP(sp);
499 
500 	/* No reason to do anything if we're in input mode on the info line. */
501 	if (F_ISSET(sp, SC_TINPUT_INFO))
502 		return (0);
503 
504 	/*
505 	 * Try and avoid getting the last line in the file, by getting the
506 	 * line after the last line in the screen -- if it exists, we know
507 	 * we have to to number all the lines in the screen.  Get the one
508 	 * after the last instead of the last, so that the info line doesn't
509 	 * fool us.  (The problem is that file_lline will lie, and tell us
510 	 * that the info line is the last line in the file.) If that test
511 	 * fails, we have to check each line for existence.
512 	 */
513 	exist = db_exist(sp, TMAP->lno + 1);
514 
515 	(void)gp->scr_cursor(sp, &oldy, &oldx);
516 	for (smp = HMAP; smp <= TMAP; ++smp) {
517 		/* Numbers are only displayed for the first screen line. */
518 		if (O_ISSET(sp, O_LEFTRIGHT)) {
519 			if (smp->coff != 0)
520 				continue;
521 		} else
522 			if (smp->soff != 1)
523 				continue;
524 
525 		/*
526 		 * The first line of an empty file gets numbered, otherwise
527 		 * number any existing line.
528 		 */
529 		if (smp->lno != 1 && !exist && !db_exist(sp, smp->lno))
530 			break;
531 
532 		(void)gp->scr_move(sp, smp - HMAP, 0);
533 		len = snprintf(nbuf, sizeof(nbuf), O_NUMBER_FMT, (u_long)smp->lno);
534 		(void)gp->scr_addstr(sp, nbuf, len);
535 	}
536 	(void)gp->scr_move(sp, oldy, oldx);
537 	return (0);
538 }
539