xref: /freebsd/contrib/nvi/vi/vs_line.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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 #if 0
14 static const char sccsid[] = "@(#)vs_line.c	10.19 (Berkeley) 9/26/96";
15 #endif
16 static const char rcsid[] =
17   "$FreeBSD$";
18 #endif /* not lint */
19 
20 #include <sys/types.h>
21 #include <sys/queue.h>
22 #include <sys/time.h>
23 
24 #include <bitstring.h>
25 #include <limits.h>
26 #include <stdio.h>
27 #include <string.h>
28 
29 #include "../common/common.h"
30 #include "vi.h"
31 
32 #ifdef VISIBLE_TAB_CHARS
33 #define	TABCH	'-'
34 #else
35 #define	TABCH	' '
36 #endif
37 
38 /*
39  * vs_line --
40  *	Update one line on the screen.
41  *
42  * PUBLIC: int vs_line __P((SCR *, SMAP *, size_t *, size_t *));
43  */
44 int
45 vs_line(sp, smp, yp, xp)
46 	SCR *sp;
47 	SMAP *smp;
48 	size_t *xp, *yp;
49 {
50 	CHAR_T *kp;
51 	GS *gp;
52 	SMAP *tsmp;
53 	size_t chlen, cno_cnt, cols_per_screen, len, nlen;
54 	size_t offset_in_char, offset_in_line, oldx, oldy;
55 	size_t scno, skip_cols, skip_screens;
56 	int ch, dne, is_cached, is_partial, is_tab, no_draw;
57 	int list_tab, list_dollar;
58 	char *p, *cbp, *ecbp, cbuf[128];
59 
60 #if defined(DEBUG) && 0
61 	TRACE(sp, "vs_line: row %u: line: %u off: %u\n",
62 	    smp - HMAP, smp->lno, smp->off);
63 #endif
64 	/*
65 	 * If ex modifies the screen after ex output is already on the screen,
66 	 * don't touch it -- we'll get scrolling wrong, at best.
67 	 */
68 	no_draw = 0;
69 	if (!F_ISSET(sp, SC_TINPUT_INFO) && VIP(sp)->totalcount > 1)
70 		no_draw = 1;
71 	if (F_ISSET(sp, SC_SCR_EXWROTE) && smp - HMAP != LASTLINE(sp))
72 		no_draw = 1;
73 
74 	/*
75 	 * Assume that, if the cache entry for the line is filled in, the
76 	 * line is already on the screen, and all we need to do is return
77 	 * the cursor position.  If the calling routine doesn't need the
78 	 * cursor position, we can just return.
79 	 */
80 	is_cached = SMAP_CACHE(smp);
81 	if (yp == NULL && (is_cached || no_draw))
82 		return (0);
83 
84 	/*
85 	 * A nasty side effect of this routine is that it returns the screen
86 	 * position for the "current" character.  Not pretty, but this is the
87 	 * only routine that really knows what's out there.
88 	 *
89 	 * Move to the line.  This routine can be called by vs_sm_position(),
90 	 * which uses it to fill in the cache entry so it can figure out what
91 	 * the real contents of the screen are.  Because of this, we have to
92 	 * return to whereever we started from.
93 	 */
94 	gp = sp->gp;
95 	(void)gp->scr_cursor(sp, &oldy, &oldx);
96 	(void)gp->scr_move(sp, smp - HMAP, 0);
97 
98 	/* Get the line. */
99 	dne = db_get(sp, smp->lno, 0, &p, &len);
100 
101 	/*
102 	 * Special case if we're printing the info/mode line.  Skip printing
103 	 * the leading number, as well as other minor setup.  The only time
104 	 * this code paints the mode line is when the user is entering text
105 	 * for a ":" command, so we can put the code here instead of dealing
106 	 * with the empty line logic below.  This is a kludge, but it's pretty
107 	 * much confined to this module.
108 	 *
109 	 * Set the number of columns for this screen.
110 	 * Set the number of chars or screens to skip until a character is to
111 	 * be displayed.
112 	 */
113 	cols_per_screen = sp->cols;
114 	if (O_ISSET(sp, O_LEFTRIGHT)) {
115 		skip_screens = 0;
116 		skip_cols = smp->coff;
117 	} else {
118 		skip_screens = smp->soff - 1;
119 		skip_cols = skip_screens * cols_per_screen;
120 	}
121 
122 	list_tab = O_ISSET(sp, O_LIST);
123 	if (F_ISSET(sp, SC_TINPUT_INFO))
124 		list_dollar = 0;
125 	else {
126 		list_dollar = list_tab;
127 
128 		/*
129 		 * If O_NUMBER is set, the line doesn't exist and it's line
130 		 * number 1, i.e., an empty file, display the line number.
131 		 *
132 		 * If O_NUMBER is set, the line exists and the first character
133 		 * on the screen is the first character in the line, display
134 		 * the line number.
135 		 *
136 		 * !!!
137 		 * If O_NUMBER set, decrement the number of columns in the
138 		 * first screen.  DO NOT CHANGE THIS -- IT'S RIGHT!  The
139 		 * rest of the code expects this to reflect the number of
140 		 * columns in the first screen, regardless of the number of
141 		 * columns we're going to skip.
142 		 */
143 		if (O_ISSET(sp, O_NUMBER)) {
144 			cols_per_screen -= O_NUMBER_LENGTH;
145 			if ((!dne || smp->lno == 1) && skip_cols == 0) {
146 				nlen = snprintf(cbuf, sizeof(cbuf),
147 				    O_NUMBER_FMT, (u_long)smp->lno);
148 				(void)gp->scr_addstr(sp, cbuf, nlen);
149 			}
150 		}
151 	}
152 
153 	/*
154 	 * Special case non-existent lines and the first line of an empty
155 	 * file.  In both cases, the cursor position is 0, but corrected
156 	 * as necessary for the O_NUMBER field, if it was displayed.
157 	 */
158 	if (dne || len == 0) {
159 		/* Fill in the cursor. */
160 		if (yp != NULL && smp->lno == sp->lno) {
161 			*yp = smp - HMAP;
162 			*xp = sp->cols - cols_per_screen;
163 		}
164 
165 		/* If the line is on the screen, quit. */
166 		if (is_cached || no_draw)
167 			goto ret1;
168 
169 		/* Set line cache information. */
170 		smp->c_sboff = smp->c_eboff = 0;
171 		smp->c_scoff = smp->c_eclen = 0;
172 
173 		/*
174 		 * Lots of special cases for empty lines, but they only apply
175 		 * if we're displaying the first screen of the line.
176 		 */
177 		if (skip_cols == 0)
178 			if (dne) {
179 				if (smp->lno == 1) {
180 					if (list_dollar) {
181 						ch = '$';
182 						goto empty;
183 					}
184 				} else {
185 					ch = '~';
186 					goto empty;
187 				}
188 			} else
189 				if (list_dollar) {
190 					ch = '$';
191 empty:					(void)gp->scr_addstr(sp,
192 					    KEY_NAME(sp, ch), KEY_LEN(sp, ch));
193 				}
194 
195 		(void)gp->scr_clrtoeol(sp);
196 		(void)gp->scr_move(sp, oldy, oldx);
197 		return (0);
198 	}
199 
200 	/*
201 	 * If we just wrote this or a previous line, we cached the starting
202 	 * and ending positions of that line.  The way it works is we keep
203 	 * information about the lines displayed in the SMAP.  If we're
204 	 * painting the screen in the forward direction, this saves us from
205 	 * reformatting the physical line for every line on the screen.  This
206 	 * wins big on binary files with 10K lines.
207 	 *
208 	 * Test for the first screen of the line, then the current screen line,
209 	 * then the line behind us, then do the hard work.  Note, it doesn't
210 	 * do us any good to have a line in front of us -- it would be really
211 	 * hard to try and figure out tabs in the reverse direction, i.e. how
212 	 * many spaces a tab takes up in the reverse direction depends on
213 	 * what characters preceded it.
214 	 *
215 	 * Test for the first screen of the line.
216 	 */
217 	if (skip_cols == 0) {
218 		smp->c_sboff = offset_in_line = 0;
219 		smp->c_scoff = offset_in_char = 0;
220 		p = &p[offset_in_line];
221 		goto display;
222 	}
223 
224 	/* Test to see if we've seen this exact line before. */
225 	if (is_cached) {
226 		offset_in_line = smp->c_sboff;
227 		offset_in_char = smp->c_scoff;
228 		p = &p[offset_in_line];
229 
230 		/* Set cols_per_screen to 2nd and later line length. */
231 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
232 			cols_per_screen = sp->cols;
233 		goto display;
234 	}
235 
236 	/* Test to see if we saw an earlier part of this line before. */
237 	if (smp != HMAP &&
238 	    SMAP_CACHE(tsmp = smp - 1) && tsmp->lno == smp->lno) {
239 		if (tsmp->c_eclen != tsmp->c_ecsize) {
240 			offset_in_line = tsmp->c_eboff;
241 			offset_in_char = tsmp->c_eclen;
242 		} else {
243 			offset_in_line = tsmp->c_eboff + 1;
244 			offset_in_char = 0;
245 		}
246 
247 		/* Put starting info for this line in the cache. */
248 		smp->c_sboff = offset_in_line;
249 		smp->c_scoff = offset_in_char;
250 		p = &p[offset_in_line];
251 
252 		/* Set cols_per_screen to 2nd and later line length. */
253 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
254 			cols_per_screen = sp->cols;
255 		goto display;
256 	}
257 
258 	scno = 0;
259 	offset_in_line = 0;
260 	offset_in_char = 0;
261 
262 	/* Do it the hard way, for leftright scrolling screens. */
263 	if (O_ISSET(sp, O_LEFTRIGHT)) {
264 		for (; offset_in_line < len; ++offset_in_line) {
265 			chlen = (ch = *(u_char *)p++) == '\t' && !list_tab ?
266 			    TAB_OFF(scno) : KEY_LEN(sp, ch);
267 			if ((scno += chlen) >= skip_cols)
268 				break;
269 		}
270 
271 		/* Set cols_per_screen to 2nd and later line length. */
272 		cols_per_screen = sp->cols;
273 
274 		/* Put starting info for this line in the cache. */
275 		if (offset_in_line >= len) {
276 			smp->c_sboff = offset_in_line;
277 			smp->c_scoff = 255;
278 		} else if (scno != skip_cols) {
279 			smp->c_sboff = offset_in_line;
280 			smp->c_scoff =
281 			    offset_in_char = chlen - (scno - skip_cols);
282 			--p;
283 		} else {
284 			smp->c_sboff = ++offset_in_line;
285 			smp->c_scoff = 0;
286 		}
287 	}
288 
289 	/* Do it the hard way, for historic line-folding screens. */
290 	else {
291 		for (; offset_in_line < len; ++offset_in_line) {
292 			chlen = (ch = *(u_char *)p++) == '\t' && !list_tab ?
293 			    TAB_OFF(scno) : KEY_LEN(sp, ch);
294 			if ((scno += chlen) < cols_per_screen)
295 				continue;
296 			scno -= cols_per_screen;
297 
298 			/* Set cols_per_screen to 2nd and later line length. */
299 			cols_per_screen = sp->cols;
300 
301 			/*
302 			 * If crossed the last skipped screen boundary, start
303 			 * displaying the characters.
304 			 */
305 			if (--skip_screens == 0)
306 				break;
307 		}
308 
309 		/* Put starting info for this line in the cache. */
310 		if (scno != 0) {
311 			smp->c_sboff = offset_in_line;
312 			smp->c_scoff = offset_in_char = chlen - scno;
313 			--p;
314 		} else {
315 			smp->c_sboff = ++offset_in_line;
316 			smp->c_scoff = 0;
317 		}
318 	}
319 
320 display:
321 	/*
322 	 * Set the number of characters to skip before reaching the cursor
323 	 * character.  Offset by 1 and use 0 as a flag value.  Vs_line is
324 	 * called repeatedly with a valid pointer to a cursor position.
325 	 * Don't fill anything in unless it's the right line and the right
326 	 * character, and the right part of the character...
327 	 */
328 	if (yp == NULL ||
329 	    smp->lno != sp->lno || sp->cno < offset_in_line ||
330 	    offset_in_line + cols_per_screen < sp->cno) {
331 		cno_cnt = 0;
332 		/* If the line is on the screen, quit. */
333 		if (is_cached || no_draw)
334 			goto ret1;
335 	} else
336 		cno_cnt = (sp->cno - offset_in_line) + 1;
337 
338 	/* This is the loop that actually displays characters. */
339 	ecbp = (cbp = cbuf) + sizeof(cbuf) - 1;
340 	for (is_partial = 0, scno = 0;
341 	    offset_in_line < len; ++offset_in_line, offset_in_char = 0) {
342 		if ((ch = *(u_char *)p++) == '\t' && !list_tab) {
343 			scno += chlen = TAB_OFF(scno) - offset_in_char;
344 			is_tab = 1;
345 		} else {
346 			scno += chlen = KEY_LEN(sp, ch) - offset_in_char;
347 			is_tab = 0;
348 		}
349 
350 		/*
351 		 * Only display up to the right-hand column.  Set a flag if
352 		 * the entire character wasn't displayed for use in setting
353 		 * the cursor.  If reached the end of the line, set the cache
354 		 * info for the screen.  Don't worry about there not being
355 		 * characters to display on the next screen, its lno/off won't
356 		 * match up in that case.
357 		 */
358 		if (scno >= cols_per_screen) {
359 			if (is_tab == 1) {
360 				chlen -= scno - cols_per_screen;
361 				smp->c_ecsize = smp->c_eclen = chlen;
362 				scno = cols_per_screen;
363 			} else {
364 				smp->c_ecsize = chlen;
365 				chlen -= scno - cols_per_screen;
366 				smp->c_eclen = chlen;
367 
368 				if (scno > cols_per_screen)
369 					is_partial = 1;
370 			}
371 			smp->c_eboff = offset_in_line;
372 
373 			/* Terminate the loop. */
374 			offset_in_line = len;
375 		}
376 
377 		/*
378 		 * If the caller wants the cursor value, and this was the
379 		 * cursor character, set the value.  There are two ways to
380 		 * put the cursor on a character -- if it's normal display
381 		 * mode, it goes on the last column of the character.  If
382 		 * it's input mode, it goes on the first.  In normal mode,
383 		 * set the cursor only if the entire character was displayed.
384 		 */
385 		if (cno_cnt &&
386 		    --cno_cnt == 0 && (F_ISSET(sp, SC_TINPUT) || !is_partial)) {
387 			*yp = smp - HMAP;
388 			if (F_ISSET(sp, SC_TINPUT))
389 				*xp = scno - chlen;
390 			else
391 				*xp = scno - 1;
392 			if (O_ISSET(sp, O_NUMBER) &&
393 			    !F_ISSET(sp, SC_TINPUT_INFO) && skip_cols == 0)
394 				*xp += O_NUMBER_LENGTH;
395 
396 			/* If the line is on the screen, quit. */
397 			if (is_cached || no_draw)
398 				goto ret1;
399 		}
400 
401 		/* If the line is on the screen, don't display anything. */
402 		if (is_cached || no_draw)
403 			continue;
404 
405 #define	FLUSH {								\
406 	*cbp = '\0';							\
407 	(void)gp->scr_addstr(sp, cbuf, cbp - cbuf);			\
408 	cbp = cbuf;							\
409 }
410 		/*
411 		 * Display the character.  We do tab expansion here because
412 		 * the screen interface doesn't have any way to set the tab
413 		 * length.  Note, it's theoretically possible for chlen to
414 		 * be larger than cbuf, if the user set a impossibly large
415 		 * tabstop.
416 		 */
417 		if (is_tab)
418 			while (chlen--) {
419 				if (cbp >= ecbp)
420 					FLUSH;
421 				*cbp++ = TABCH;
422 			}
423 		else {
424 			if (cbp + chlen >= ecbp)
425 				FLUSH;
426 			for (kp = KEY_NAME(sp, ch) + offset_in_char; chlen--;)
427 				*cbp++ = *kp++;
428 		}
429 	}
430 
431 	if (scno < cols_per_screen) {
432 		/* If didn't paint the whole line, update the cache. */
433 		smp->c_ecsize = smp->c_eclen = KEY_LEN(sp, ch);
434 		smp->c_eboff = len - 1;
435 
436 		/*
437 		 * If not the info/mode line, and O_LIST set, and at the
438 		 * end of the line, and the line ended on this screen,
439 		 * add a trailing $.
440 		 */
441 		if (list_dollar) {
442 			++scno;
443 
444 			chlen = KEY_LEN(sp, '$');
445 			if (cbp + chlen >= ecbp)
446 				FLUSH;
447 			for (kp = KEY_NAME(sp, '$'); chlen--;)
448 				*cbp++ = *kp++;
449 		}
450 
451 		/* If still didn't paint the whole line, clear the rest. */
452 		if (scno < cols_per_screen)
453 			(void)gp->scr_clrtoeol(sp);
454 	}
455 
456 	/* Flush any buffered characters. */
457 	if (cbp > cbuf)
458 		FLUSH;
459 
460 ret1:	(void)gp->scr_move(sp, oldy, oldx);
461 	return (0);
462 }
463 
464 /*
465  * vs_number --
466  *	Repaint the numbers on all the lines.
467  *
468  * PUBLIC: int vs_number __P((SCR *));
469  */
470 int
471 vs_number(sp)
472 	SCR *sp;
473 {
474 	GS *gp;
475 	SMAP *smp;
476 	VI_PRIVATE *vip;
477 	size_t len, oldy, oldx;
478 	int exist;
479 	char nbuf[10];
480 
481 	gp = sp->gp;
482 	vip = VIP(sp);
483 
484 	/* No reason to do anything if we're in input mode on the info line. */
485 	if (F_ISSET(sp, SC_TINPUT_INFO))
486 		return (0);
487 
488 	/*
489 	 * Try and avoid getting the last line in the file, by getting the
490 	 * line after the last line in the screen -- if it exists, we know
491 	 * we have to to number all the lines in the screen.  Get the one
492 	 * after the last instead of the last, so that the info line doesn't
493 	 * fool us.  (The problem is that file_lline will lie, and tell us
494 	 * that the info line is the last line in the file.) If that test
495 	 * fails, we have to check each line for existence.
496 	 */
497 	exist = db_exist(sp, TMAP->lno + 1);
498 
499 	(void)gp->scr_cursor(sp, &oldy, &oldx);
500 	for (smp = HMAP; smp <= TMAP; ++smp) {
501 		/* Numbers are only displayed for the first screen line. */
502 		if (O_ISSET(sp, O_LEFTRIGHT)) {
503 			if (smp->coff != 0)
504 				continue;
505 		} else
506 			if (smp->soff != 1)
507 				continue;
508 
509 		/*
510 		 * The first line of an empty file gets numbered, otherwise
511 		 * number any existing line.
512 		 */
513 		if (smp->lno != 1 && !exist && !db_exist(sp, smp->lno))
514 			break;
515 
516 		(void)gp->scr_move(sp, smp - HMAP, 0);
517 		len = snprintf(nbuf, sizeof(nbuf),
518 		    O_NUMBER_FMT, (u_long)smp->lno);
519 		(void)gp->scr_addstr(sp, nbuf, len);
520 	}
521 	(void)gp->scr_move(sp, oldy, oldx);
522 	return (0);
523 }
524