xref: /freebsd/contrib/nvi/vi/vs_line.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
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 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.h>
15 
16 #include <bitstring.h>
17 #include <limits.h>
18 #include <stdio.h>
19 #include <string.h>
20 
21 #include "../common/common.h"
22 #include "vi.h"
23 
24 #ifdef VISIBLE_TAB_CHARS
25 #define	TABCH	'-'
26 #else
27 #define	TABCH	' '
28 #endif
29 
30 /*
31  * vs_line --
32  *	Update one line on the screen.
33  *
34  * PUBLIC: int vs_line(SCR *, SMAP *, size_t *, size_t *);
35  */
36 int
37 vs_line(SCR *sp, SMAP *smp, size_t *yp, size_t *xp)
38 {
39 	u_char *kp;
40 	GS *gp;
41 	SMAP *tsmp;
42 	size_t chlen = 0, cno_cnt, cols_per_screen, len, nlen;
43 	size_t offset_in_char, offset_in_line, oldx, oldy;
44 	size_t scno, skip_cols, skip_screens;
45 	int dne, is_cached, is_partial, is_tab, no_draw;
46 	int list_tab, list_dollar;
47 	CHAR_T *p;
48 	CHAR_T *cbp, *ecbp, cbuf[128];
49 	ARG_CHAR_T ch = '\0';
50 
51 #if defined(DEBUG) && 0
52 	TRACE(sp, "vs_line: row %u: line: %u off: %u\n",
53 	    smp - HMAP, smp->lno, smp->off);
54 #endif
55 	/*
56 	 * If ex modifies the screen after ex output is already on the screen,
57 	 * don't touch it -- we'll get scrolling wrong, at best.
58 	 */
59 	no_draw = 0;
60 	if (!F_ISSET(sp, SC_TINPUT_INFO) && VIP(sp)->totalcount > 1)
61 		no_draw = 1;
62 	if (F_ISSET(sp, SC_SCR_EXWROTE) && smp - HMAP != LASTLINE(sp))
63 		no_draw = 1;
64 
65 	/*
66 	 * Assume that, if the cache entry for the line is filled in, the
67 	 * line is already on the screen, and all we need to do is return
68 	 * the cursor position.  If the calling routine doesn't need the
69 	 * cursor position, we can just return.
70 	 */
71 	is_cached = SMAP_CACHE(smp);
72 	if (yp == NULL && (is_cached || no_draw))
73 		return (0);
74 
75 	/*
76 	 * A nasty side effect of this routine is that it returns the screen
77 	 * position for the "current" character.  Not pretty, but this is the
78 	 * only routine that really knows what's out there.
79 	 *
80 	 * Move to the line.  This routine can be called by vs_sm_position(),
81 	 * which uses it to fill in the cache entry so it can figure out what
82 	 * the real contents of the screen are.  Because of this, we have to
83 	 * return to whereever we started from.
84 	 */
85 	gp = sp->gp;
86 	(void)gp->scr_cursor(sp, &oldy, &oldx);
87 	(void)gp->scr_move(sp, smp - HMAP, 0);
88 
89 	/* Get the line. */
90 	dne = db_get(sp, smp->lno, 0, &p, &len);
91 
92 	/*
93 	 * Special case if we're printing the info/mode line.  Skip printing
94 	 * the leading number, as well as other minor setup.  The only time
95 	 * this code paints the mode line is when the user is entering text
96 	 * for a ":" command, so we can put the code here instead of dealing
97 	 * with the empty line logic below.  This is a kludge, but it's pretty
98 	 * much confined to this module.
99 	 *
100 	 * Set the number of columns for this screen.
101 	 * Set the number of chars or screens to skip until a character is to
102 	 * be displayed.
103 	 */
104 	cols_per_screen = sp->cols;
105 	if (O_ISSET(sp, O_LEFTRIGHT)) {
106 		skip_screens = 0;
107 		skip_cols = smp->coff;
108 	} else {
109 		skip_screens = smp->soff - 1;
110 		skip_cols = skip_screens * cols_per_screen;
111 	}
112 
113 	list_tab = O_ISSET(sp, O_LIST);
114 	if (F_ISSET(sp, SC_TINPUT_INFO))
115 		list_dollar = 0;
116 	else {
117 		list_dollar = list_tab;
118 
119 		/*
120 		 * If O_NUMBER is set, the line doesn't exist and it's line
121 		 * number 1, i.e., an empty file, display the line number.
122 		 *
123 		 * If O_NUMBER is set, the line exists and the first character
124 		 * on the screen is the first character in the line, display
125 		 * the line number.
126 		 *
127 		 * !!!
128 		 * If O_NUMBER set, decrement the number of columns in the
129 		 * first screen.  DO NOT CHANGE THIS -- IT'S RIGHT!  The
130 		 * rest of the code expects this to reflect the number of
131 		 * columns in the first screen, regardless of the number of
132 		 * columns we're going to skip.
133 		 */
134 		if (O_ISSET(sp, O_NUMBER)) {
135 			cols_per_screen -= O_NUMBER_LENGTH;
136 			if ((!dne || smp->lno == 1) && skip_cols == 0) {
137 				nlen = snprintf((char*)cbuf,
138 				    sizeof(cbuf), O_NUMBER_FMT, (u_long)smp->lno);
139 				(void)gp->scr_addstr(sp, (char*)cbuf, nlen);
140 			}
141 		}
142 	}
143 
144 	/*
145 	 * Special case non-existent lines and the first line of an empty
146 	 * file.  In both cases, the cursor position is 0, but corrected
147 	 * as necessary for the O_NUMBER field, if it was displayed.
148 	 */
149 	if (dne || len == 0) {
150 		/* Fill in the cursor. */
151 		if (yp != NULL && smp->lno == sp->lno) {
152 			*yp = smp - HMAP;
153 			*xp = sp->cols - cols_per_screen;
154 		}
155 
156 		/* If the line is on the screen, quit. */
157 		if (is_cached || no_draw)
158 			goto ret1;
159 
160 		/* Set line cache information. */
161 		smp->c_sboff = smp->c_eboff = 0;
162 		smp->c_scoff = smp->c_eclen = 0;
163 
164 		/*
165 		 * Lots of special cases for empty lines, but they only apply
166 		 * if we're displaying the first screen of the line.
167 		 */
168 		if (skip_cols == 0) {
169 			if (dne) {
170 				if (smp->lno == 1) {
171 					if (list_dollar) {
172 						ch = '$';
173 						goto empty;
174 					}
175 				} else {
176 					ch = '~';
177 					goto empty;
178 				}
179 			} else {
180 				if (list_dollar) {
181 					ch = '$';
182 empty:					(void)gp->scr_addstr(sp,
183 					    KEY_NAME(sp, ch), KEY_LEN(sp, ch));
184 				}
185 			}
186 		}
187 
188 		(void)gp->scr_clrtoeol(sp);
189 		(void)gp->scr_move(sp, oldy, oldx);
190 		return (0);
191 	}
192 
193 	/* If we shortened this line in another screen, the cursor
194 	 * position may have fallen off.
195 	 */
196 	if (sp->lno == smp->lno && sp->cno >= len)
197 	    sp->cno = len - 1;
198 
199 	/*
200 	 * If we just wrote this or a previous line, we cached the starting
201 	 * and ending positions of that line.  The way it works is we keep
202 	 * information about the lines displayed in the SMAP.  If we're
203 	 * painting the screen in the forward direction, this saves us from
204 	 * reformatting the physical line for every line on the screen.  This
205 	 * wins big on binary files with 10K lines.
206 	 *
207 	 * Test for the first screen of the line, then the current screen line,
208 	 * then the line behind us, then do the hard work.  Note, it doesn't
209 	 * do us any good to have a line in front of us -- it would be really
210 	 * hard to try and figure out tabs in the reverse direction, i.e. how
211 	 * many spaces a tab takes up in the reverse direction depends on
212 	 * what characters preceded it.
213 	 *
214 	 * Test for the first screen of the line.
215 	 */
216 	if (skip_cols == 0) {
217 		smp->c_sboff = offset_in_line = 0;
218 		smp->c_scoff = offset_in_char = 0;
219 		p = &p[offset_in_line];
220 		goto display;
221 	}
222 
223 	/* Test to see if we've seen this exact line before. */
224 	if (is_cached) {
225 		offset_in_line = smp->c_sboff;
226 		offset_in_char = smp->c_scoff;
227 		p = &p[offset_in_line];
228 
229 		/* Set cols_per_screen to 2nd and later line length. */
230 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
231 			cols_per_screen = sp->cols;
232 		goto display;
233 	}
234 
235 	/* Test to see if we saw an earlier part of this line before. */
236 	if (smp != HMAP &&
237 	    SMAP_CACHE(tsmp = smp - 1) && tsmp->lno == smp->lno) {
238 		if (tsmp->c_eclen != tsmp->c_ecsize) {
239 			offset_in_line = tsmp->c_eboff;
240 			offset_in_char = tsmp->c_eclen;
241 		} else {
242 			offset_in_line = tsmp->c_eboff + 1;
243 			offset_in_char = 0;
244 		}
245 
246 		/* Put starting info for this line in the cache. */
247 		smp->c_sboff = offset_in_line;
248 		smp->c_scoff = offset_in_char;
249 		p = &p[offset_in_line];
250 
251 		/* Set cols_per_screen to 2nd and later line length. */
252 		if (O_ISSET(sp, O_LEFTRIGHT) || skip_cols > cols_per_screen)
253 			cols_per_screen = sp->cols;
254 		goto display;
255 	}
256 
257 	scno = 0;
258 	offset_in_line = 0;
259 	offset_in_char = 0;
260 
261 	/* Do it the hard way, for leftright scrolling screens. */
262 	if (O_ISSET(sp, O_LEFTRIGHT)) {
263 		for (; offset_in_line < len; ++offset_in_line) {
264 			chlen = (ch = *p++) == '\t' && !list_tab ?
265 			    TAB_OFF(scno) : KEY_COL(sp, ch);
266 			if ((scno += chlen) >= skip_cols)
267 				break;
268 		}
269 
270 		/* Set cols_per_screen to 2nd and later line length. */
271 		cols_per_screen = sp->cols;
272 
273 		/* Put starting info for this line in the cache. */
274 		if (offset_in_line >= len) {
275 			smp->c_sboff = offset_in_line;
276 			smp->c_scoff = 255;
277 		} else if (scno != skip_cols) {
278 			smp->c_sboff = offset_in_line;
279 			smp->c_scoff =
280 			    offset_in_char = chlen - (scno - skip_cols);
281 			--p;
282 		} else {
283 			smp->c_sboff = ++offset_in_line;
284 			smp->c_scoff = 0;
285 		}
286 	}
287 
288 	/* Do it the hard way, for historic line-folding screens. */
289 	else {
290 		for (; offset_in_line < len; ++offset_in_line) {
291 			chlen = (ch = *p++) == '\t' && !list_tab ?
292 			    TAB_OFF(scno) : KEY_COL(sp, ch);
293 			if ((scno += chlen) < cols_per_screen)
294 				continue;
295 			scno -= cols_per_screen;
296 
297 			/* Set cols_per_screen to 2nd and later line length. */
298 			cols_per_screen = sp->cols;
299 
300 			/*
301 			 * If crossed the last skipped screen boundary, start
302 			 * displaying the characters.
303 			 */
304 			if (--skip_screens == 0)
305 				break;
306 		}
307 
308 		/* Put starting info for this line in the cache. */
309 		if (scno != 0) {
310 			smp->c_sboff = offset_in_line;
311 			smp->c_scoff = offset_in_char = chlen - scno;
312 			--p;
313 		} else {
314 			smp->c_sboff = ++offset_in_line;
315 			smp->c_scoff = 0;
316 		}
317 	}
318 
319 display:
320 	/*
321 	 * Set the number of characters to skip before reaching the cursor
322 	 * character.  Offset by 1 and use 0 as a flag value.  Vs_line is
323 	 * called repeatedly with a valid pointer to a cursor position.
324 	 * Don't fill anything in unless it's the right line and the right
325 	 * character, and the right part of the character...
326 	 */
327 	if (yp == NULL ||
328 	    smp->lno != sp->lno || sp->cno < offset_in_line ||
329 	    offset_in_line + cols_per_screen < sp->cno) {
330 		cno_cnt = 0;
331 		/* If the line is on the screen, quit. */
332 		if (is_cached || no_draw)
333 			goto ret1;
334 	} else
335 		cno_cnt = (sp->cno - offset_in_line) + 1;
336 
337 	/* This is the loop that actually displays characters. */
338 	ecbp = (cbp = cbuf) + SIZE(cbuf) - 1;
339 	for (is_partial = 0, scno = 0;
340 	    offset_in_line < len; ++offset_in_line, offset_in_char = 0) {
341 		if ((ch = *p++) == '\t' && !list_tab) {
342 			scno += chlen = TAB_OFF(scno) - offset_in_char;
343 			is_tab = 1;
344 		} else {
345 			scno += chlen = KEY_COL(sp, ch) - offset_in_char;
346 			is_tab = 0;
347 		}
348 
349 		/*
350 		 * Only display up to the right-hand column.  Set a flag if
351 		 * the entire character wasn't displayed for use in setting
352 		 * the cursor.  If reached the end of the line, set the cache
353 		 * info for the screen.  Don't worry about there not being
354 		 * characters to display on the next screen, its lno/off won't
355 		 * match up in that case.
356 		 */
357 		if (scno >= cols_per_screen) {
358 			if (is_tab == 1) {
359 				chlen -= scno - cols_per_screen;
360 				smp->c_ecsize = smp->c_eclen = chlen;
361 				scno = cols_per_screen;
362 			} else {
363 				smp->c_ecsize = chlen;
364 				chlen -= scno - cols_per_screen;
365 				smp->c_eclen = chlen;
366 
367 				if (scno > cols_per_screen)
368 					is_partial = 1;
369 			}
370 			smp->c_eboff = offset_in_line;
371 
372 			/* Terminate the loop. */
373 			offset_in_line = len;
374 		}
375 
376 		/*
377 		 * If the caller wants the cursor value, and this was the
378 		 * cursor character, set the value.  There are two ways to
379 		 * put the cursor on a character -- if it's normal display
380 		 * mode, it goes on the last column of the character.  If
381 		 * it's input mode, it goes on the first.  In normal mode,
382 		 * set the cursor only if the entire character was displayed.
383 		 */
384 		if (cno_cnt &&
385 		    --cno_cnt == 0 && (F_ISSET(sp, SC_TINPUT) || !is_partial)) {
386 			*yp = smp - HMAP;
387 			if (F_ISSET(sp, SC_TINPUT))
388 				if (is_partial)
389 					*xp = scno - smp->c_ecsize;
390 				else
391 					*xp = scno - chlen;
392 			else
393 				*xp = scno - 1;
394 			if (O_ISSET(sp, O_NUMBER) &&
395 			    !F_ISSET(sp, SC_TINPUT_INFO) && skip_cols == 0)
396 				*xp += O_NUMBER_LENGTH;
397 
398 			/* If the line is on the screen, quit. */
399 			if (is_cached || no_draw)
400 				goto ret1;
401 		}
402 
403 		/* If the line is on the screen, don't display anything. */
404 		if (is_cached || no_draw)
405 			continue;
406 
407 #define	FLUSH do {							\
408 	*cbp = '\0';							\
409 	(void)gp->scr_waddstr(sp, cbuf, cbp - cbuf);			\
410 	cbp = cbuf;							\
411 } while (0)
412 		/*
413 		 * Display the character.  We do tab expansion here because
414 		 * the screen interface doesn't have any way to set the tab
415 		 * length.  Note, it's theoretically possible for chlen to
416 		 * be larger than cbuf, if the user set a impossibly large
417 		 * tabstop.
418 		 */
419 		if (is_tab)
420 			while (chlen--) {
421 				if (cbp >= ecbp)
422 					FLUSH;
423 				*cbp++ = TABCH;
424 			}
425 		else {
426 			if (cbp + chlen >= ecbp)
427 				FLUSH;
428 
429 			/* don't display half a wide character */
430 			if (is_partial && XCHAR_WIDTH(sp, ch) > 1) {
431 				*cbp++ = ' ';
432 				break;
433 			}
434 
435 			if (KEY_NEEDSWIDE(sp, ch))
436 				*cbp++ = ch;
437 			else
438 				for (kp = (u_char *)
439 				    KEY_NAME(sp, ch) + offset_in_char;
440 				    chlen--;)
441 					*cbp++ = *kp++;
442 		}
443 	}
444 
445 	if (scno < cols_per_screen) {
446 		/* If didn't paint the whole line, update the cache. */
447 		smp->c_ecsize = smp->c_eclen = KEY_COL(sp, ch);
448 		smp->c_eboff = len - 1;
449 
450 		/*
451 		 * If not the info/mode line, and O_LIST set, and at the
452 		 * end of the line, and the line ended on this screen,
453 		 * add a trailing $.
454 		 */
455 		if (list_dollar) {
456 			++scno;
457 
458 			chlen = KEY_LEN(sp, '$');
459 			if (cbp + chlen >= ecbp)
460 				FLUSH;
461 			for (kp = (u_char *)
462 			    KEY_NAME(sp, '$'); chlen--;)
463 				*cbp++ = *kp++;
464 		}
465 
466 		/* If still didn't paint the whole line, clear the rest. */
467 		if (scno < cols_per_screen)
468 			(void)gp->scr_clrtoeol(sp);
469 	}
470 
471 	/* Flush any buffered characters. */
472 	if (cbp > cbuf)
473 		FLUSH;
474 
475 ret1:	(void)gp->scr_move(sp, oldy, oldx);
476 	return (0);
477 }
478 
479 /*
480  * vs_number --
481  *	Repaint the numbers on all the lines.
482  *
483  * PUBLIC: int vs_number(SCR *);
484  */
485 int
486 vs_number(SCR *sp)
487 {
488 	GS *gp;
489 	SMAP *smp;
490 	VI_PRIVATE *vip;
491 	size_t len, oldy, oldx;
492 	int exist;
493 	char nbuf[10];
494 
495 	gp = sp->gp;
496 	vip = VIP(sp);
497 
498 	/* No reason to do anything if we're in input mode on the info line. */
499 	if (F_ISSET(sp, SC_TINPUT_INFO))
500 		return (0);
501 
502 	/*
503 	 * Try and avoid getting the last line in the file, by getting the
504 	 * line after the last line in the screen -- if it exists, we know
505 	 * we have to to number all the lines in the screen.  Get the one
506 	 * after the last instead of the last, so that the info line doesn't
507 	 * fool us.  (The problem is that file_lline will lie, and tell us
508 	 * that the info line is the last line in the file.) If that test
509 	 * fails, we have to check each line for existence.
510 	 */
511 	exist = db_exist(sp, TMAP->lno + 1);
512 
513 	(void)gp->scr_cursor(sp, &oldy, &oldx);
514 	for (smp = HMAP; smp <= TMAP; ++smp) {
515 		/* Numbers are only displayed for the first screen line. */
516 		if (O_ISSET(sp, O_LEFTRIGHT)) {
517 			if (smp->coff != 0)
518 				continue;
519 		} else
520 			if (smp->soff != 1)
521 				continue;
522 
523 		/*
524 		 * The first line of an empty file gets numbered, otherwise
525 		 * number any existing line.
526 		 */
527 		if (smp->lno != 1 && !exist && !db_exist(sp, smp->lno))
528 			break;
529 
530 		(void)gp->scr_move(sp, smp - HMAP, 0);
531 		len = snprintf(nbuf, sizeof(nbuf), O_NUMBER_FMT, (u_long)smp->lno);
532 		(void)gp->scr_addstr(sp, nbuf, len);
533 	}
534 	(void)gp->scr_move(sp, oldy, oldx);
535 	return (0);
536 }
537