xref: /netbsd-src/lib/libcurses/cr_put.c (revision 2718af68c3efc72c9769069b5c7f9ed36f6b9def)
1 /*	$NetBSD: cr_put.c,v 1.39 2022/04/10 09:50:44 andvar Exp $	*/
2 
3 /*
4  * Copyright (c) 1981, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include <limits.h>
34 #include <stdlib.h>
35 #ifndef lint
36 #if 0
37 static char sccsid[] = "@(#)cr_put.c	8.3 (Berkeley) 5/4/94";
38 #else
39 __RCSID("$NetBSD: cr_put.c,v 1.39 2022/04/10 09:50:44 andvar Exp $");
40 #endif
41 #endif				/* not lint */
42 
43 #include <string.h>
44 
45 #include "curses.h"
46 #include "curses_private.h"
47 
48 #define	HARDTABS	8
49 
50 /*
51  * Terminal driving and line formatting routines.  Basic motion optimizations
52  * are done here as well as formatting lines (printing of control characters,
53  * line numbering and the like).
54  */
55 
56 /* Stub function for the users. */
57 int
58 mvcur(int ly, int lx, int y, int x)
59 {
60 	return (__mvcur(ly, lx, y, x, 0));
61 }
62 
63 static void fgoto(int);
64 static int plod(int, int);
65 static int plodput(int);
66 static int tabcol(int, int);
67 
68 static int outcol, outline, destcol, destline;
69 
70 /*
71  * Sync the position of the output cursor.  Most work here is rounding for
72  * terminal boundaries getting the column position implied by wraparound or
73  * the lack thereof and rolling up the screen to get destline on the screen.
74  */
75 int
76 __mvcur(int ly, int lx, int y, int x, int in_refresh)
77 {
78 	__CTRACE(__CTRACE_OUTPUT,
79 	    "mvcur: moving cursor from (%d, %d) to (%d, %d) in refresh %d\n",
80 	    ly, lx, y, x, in_refresh);
81 	destcol = x;
82 	destline = y;
83 	outcol = lx;
84 	outline = ly;
85 	fgoto(in_refresh);
86 	return (OK);
87 }
88 
89 static void
90 fgoto(int in_refresh)
91 {
92 	int	 c, l;
93 	char	*cgp;
94 
95 	__CTRACE(__CTRACE_OUTPUT, "fgoto: in_refresh=%d\n", in_refresh);
96 	__CTRACE(__CTRACE_OUTPUT,
97 	    "fgoto: outcol=%d, outline=%d, destcol=%d, destline=%d\n",
98 	    outcol, outline, destcol, destline);
99 	if (destcol >= COLS) {
100 		destline += destcol / COLS;
101 		destcol %= COLS;
102 	}
103 	if (outcol >= COLS) {
104 		l = (outcol + 1) / COLS;
105 		outline += l;
106 		outcol %= COLS;
107 		if (auto_left_margin == 0) {
108 			while (l > 0) {
109 				if (__pfast) {
110 					if (carriage_return)
111 						tputs(carriage_return,
112 							0, __cputchar);
113 					else
114 						__cputchar('\r');
115 				}
116 				if (cursor_down)
117 					tputs(cursor_down, 0, __cputchar);
118 				else
119 					__cputchar('\n');
120 				l--;
121 			}
122 			outcol = 0;
123 		}
124 		if (outline > LINES - 1) {
125 			destline -= outline - (LINES - 1);
126 			outline = LINES - 1;
127 		}
128 	}
129 	if (destline >= LINES) {
130 		l = destline;
131 		destline = LINES - 1;
132 		if (outline < LINES - 1) {
133 			c = destcol;
134 			if (__pfast == 0 && !cursor_address)
135 				destcol = 0;
136 			fgoto(in_refresh);
137 			destcol = c;
138 		}
139 		while (l >= LINES) {
140 			/* The following linefeed (or simulation thereof) is
141 			 * supposed to scroll up the screen, since we are on
142 			 * the bottom line.  We make the assumption that
143 			 * linefeed will scroll.  If ns is in the capability
144 			 * list this won't work.  We should probably have an
145 			 * sc capability but sf will generally take the place
146 			 * if it works.
147 			 *
148 			 * Superbee glitch: in the middle of the screen have to
149 			 * use esc B (down) because linefeed screws up in
150 			 * "Efficient Paging" (what a joke) mode (which is
151 			 * essential in some SB's because CRLF mode puts
152 			 * garbage in at end of memory), but you must use
153 			 * linefeed to scroll since down arrow won't go past
154 			 * memory end. I turned this off after receiving Paul
155 			 * Eggert's Superbee description which wins better. */
156 			if (cursor_down /* && !__tc_xb */ && __pfast)
157 				tputs(cursor_down, 0, __cputchar);
158 			else
159 				__cputchar('\n');
160 			l--;
161 			if (__pfast == 0)
162 				outcol = 0;
163 		}
164 	}
165 	if (destline < outline && !(cursor_address || cursor_up))
166 		destline = outline;
167 
168 	if (cursor_address &&
169 	    (cgp = tiparm(cursor_address, destline, destcol)))
170 	{
171 		/*
172 		 * Need this condition due to inconsistent behavior
173 		 * of backspace on the last column.
174 		 */
175 		__CTRACE(__CTRACE_OUTPUT, "fgoto: cgp=%s\n", cgp);
176 		if (outcol != COLS - 1 &&
177 		    plod((int) strlen(cgp), in_refresh) > 0)
178 			plod(0, in_refresh);
179 		else
180 			tputs(cgp, 0, __cputchar);
181 	} else
182 		plod(0, in_refresh);
183 	outline = destline;
184 	outcol = destcol;
185 }
186 
187 /*
188  * Move (slowly) to destination.
189  * Hard thing here is using home cursor on really deficient terminals.
190  * Otherwise just use cursor motions, hacking use of tabs and overtabbing
191  * and backspace.
192  *
193  */
194 
195 static int plodcnt, plodflg;
196 #ifdef HAVE_WCHAR
197 static char s[MB_LEN_MAX];
198 #endif
199 
200 static int
201 plodput(int c)
202 {
203 	if (plodflg) {
204 		int cw;
205 
206 #ifdef HAVE_WCHAR
207 		cw = wctomb(s, c);
208 		if (cw < 0)
209 			cw = 1;
210 #else
211 		cw = 1;
212 #endif /* HAVE_WCHAR */
213 
214 		plodcnt -= cw;
215 	} else
216 		__cputchar(c);
217 	return 0;
218 }
219 
220 static int
221 plod(int cnt, int in_refresh)
222 {
223 	int	 i, j, k, soutcol, soutline;
224 
225 	__CTRACE(__CTRACE_OUTPUT, "plod: cnt=%d, in_refresh=%d\n",
226 	    cnt, in_refresh);
227 	__CTRACE(__CTRACE_OUTPUT,
228 	    "plod: plodding from col %d, row %d to col %d, row %d\n",
229 	    outcol, outline, destcol, destline);
230 	plodcnt = plodflg = cnt;
231 	soutcol = outcol;
232 	soutline = outline;
233 
234 	/*
235 	 * Consider homing and moving down/right from there, vs. moving
236 	 * directly with local motions to the right spot.
237 	 */
238 	if (cursor_home) {
239 		/*
240 		 * i is the cost to home and tab/space to the right to get to
241 		 * the proper column.  This assumes nd space costs 1 char.  So
242 		 * i + destcol is cost of motion with home.
243 		 */
244 		if (__GT)
245 			i = (destcol / HARDTABS) + (destcol % HARDTABS);
246 		else
247 			i = destcol;
248 
249 		/* j is cost to move locally without homing. */
250 		if (destcol >= outcol) {	/* if motion is to the right */
251 			j = destcol / HARDTABS - outcol / HARDTABS;
252 			if (__GT && j)
253 				j += destcol % HARDTABS;
254 			else
255 				j = destcol - outcol;
256 		} else
257 			/* leftward motion only works if we can backspace. */
258 			if (outcol - destcol <= i)
259 				/* Cheaper to backspace. */
260 				i = j = outcol - destcol;
261 			else
262 				/* Impossibly expensive. */
263 				j = i + 1;
264 
265 		/* k is the absolute value of vertical distance. */
266 		k = outline - destline;
267 		if (k < 0)
268 			k = -k;
269 		j += k;
270 
271 		/* Decision.  We may not have a choice if no up. */
272 		if (i + destline < j || (!cursor_up && destline < outline)) {
273 			/*
274 			 * Cheaper to home.  Do it now and pretend it's a
275 			 * regular local motion.
276 			 */
277 			tputs(cursor_home, 0, plodput);
278 			outcol = outline = 0;
279 		} else
280 			if (cursor_to_ll) {
281 				/*
282 				 * Quickly consider homing down and moving from
283 				 * there.  Assume cost of ll is 2.
284 				 */
285 				k = (LINES - 1) - destline;
286 				if (i + k + 2 < j && (k <= 0 || cursor_up)) {
287 					tputs(cursor_to_ll, 0, plodput);
288 					outcol = 0;
289 					outline = LINES - 1;
290 				}
291 			}
292 	} else
293 		/* No home and no up means it's impossible. */
294 		if (!cursor_up && destline < outline)
295 			return (-1);
296 	if (__GT)
297 		i = destcol % HARDTABS + destcol / HARDTABS;
298 	else
299 		i = destcol;
300 #ifdef notdef
301 	if (back_tab && outcol > destcol &&
302 	    (j = (((outcol + 7) & ~7) - destcol - 1) >> 3)) {
303 		j *= (k = strlen(back_tab));
304 		if ((k += (destcol & 7)) > 4)
305 			j += 8 - (destcol & 7);
306 		else
307 			j += k;
308 	} else
309 #endif
310 		j = outcol - destcol;
311 
312 	/*
313 	 * If we will later need a \n which will turn into a \r\n by the
314 	 * system or the terminal, then don't bother to try to \r.
315 	 */
316 	if ((__NONL || !__pfast) && outline < destline)
317 		goto dontcr;
318 
319 	/*
320 	 * If the terminal will do a \r\n and there isn't room for it, then
321 	 * we can't afford a \r.
322 	 */
323 	if (!carriage_return && outline >= destline)
324 		goto dontcr;
325 
326 	/*
327 	 * If it will be cheaper, or if we can't back up, then send a return
328 	 * preliminarily.
329 	 */
330 	if (j > i + 1 || outcol > destcol) {
331 		/*
332 		 * BUG: this doesn't take the (possibly long) length of cr
333 		 * into account.
334 		 */
335 		if (carriage_return)
336 			tputs(carriage_return, 0, plodput);
337 		else
338 			plodput('\r');
339 		if (!carriage_return) {
340 			if (cursor_down)
341 				tputs(cursor_down, 0, plodput);
342 			else
343 				plodput('\n');
344 			outline++;
345 		}
346 
347 		outcol = 0;
348 	}
349 dontcr:while (outline < destline) {
350 		outline++;
351 		if (cursor_down)
352 			tputs(cursor_down, 0, plodput);
353 		else
354 			plodput('\n');
355 		if (plodcnt < 0)
356 			goto out;
357 		/*
358 		 * If the terminal does a CR with NL or we are in
359 		 * a mode where a \n will result in an implicit \r
360 		 * then adjust the outcol to match iff we actually
361 		 * emitted said \n.
362 		 */
363 		if ((__NONL || __pfast == 0) &&
364 		    (!cursor_down || (*cursor_down == '\n')))
365 			outcol = 0;
366 	}
367 #ifdef notdef
368 	if (back_tab)
369 		k = (int) strlen(back_tab);
370 #endif
371 	while (outcol > destcol) {
372 		if (plodcnt < 0)
373 			goto out;
374 #ifdef notdef
375 		if (back_tab && outcol - destcol > k + 4) {
376 			tputs(back_tab, 0, plodput);
377 			outcol--;
378 			outcol &= ~7;
379 			continue;
380 		}
381 #endif
382 		outcol--;
383 		if (cursor_left)
384 			tputs(cursor_left, 0, plodput);
385 		else
386 			plodput('\b');
387 	}
388 	while (outline > destline) {
389 		outline--;
390 		tputs(cursor_up, 0, plodput);
391 		if (plodcnt < 0)
392 			goto out;
393 	}
394 	if (__GT && destcol - outcol > 1) {
395 		for (;;) {
396 			i = tabcol(outcol, HARDTABS);
397 			if (i > destcol)
398 				break;
399 			if (tab)
400 				tputs(tab, 0, plodput);
401 			else
402 				plodput('\t');
403 			outcol = i;
404 		}
405 		if (destcol - outcol > 4 && i < COLS) {
406 			if (tab)
407 				tputs(tab, 0, plodput);
408 			else
409 				plodput('\t');
410 			outcol = i;
411 			while (outcol > destcol) {
412 				outcol--;
413 				if (cursor_left)
414 					tputs(cursor_left, 0, plodput);
415 				else
416 					plodput('\b');
417 			}
418 		}
419 	}
420 
421 #ifdef HAVE_WCHAR
422 	/*
423 	 * If destcol is halfway through a multicolumn
424 	 * wide char, we have no chance of plodding.
425 	 */
426 	k = outcol - destcol;
427 	if (k < 0)
428 		k = -k;
429 	if ((k != 0) && (curscr->alines[outline]->line[outcol].wcols > k)) {
430 		plodcnt = -1;
431 		goto out;
432 	}
433 #endif /* HAVE_WCHAR */
434 
435 	while (outcol < destcol) {
436 		/*
437 		 * Move one char to the right.  We don't use nd space because
438 		 * it's better to just print the char we are moving over.
439 		 */
440 		if (in_refresh)
441 			if (plodflg)	/* Avoid a complex calculation. */
442 				plodcnt--;
443 			else {
444 #ifndef HAVE_WCHAR
445 				i = curscr->alines[outline]->line[outcol].ch
446 				    & __CHARTEXT;
447 				if (curscr->alines[outline]->line[outcol].attr
448 				    == curscr->wattr)
449 					__cputchar(i);
450 #else
451 				if ((curscr->alines[outline]->line[outcol].attr
452 				    & WA_ATTRIBUTES)
453 				    == curscr->wattr) {
454 					switch (curscr->alines[outline]->line[outcol].wcols) {
455 					case 1:
456 						__cputwchar(curscr->alines[outline]->line[outcol].ch);
457 						__cursesi_putnsp(curscr->alines[outline]->line[outcol].nsp,
458 								outline,
459 								outcol);
460 						__CTRACE(__CTRACE_OUTPUT,
461 						    "plod: (%d,%d)wcols(%d), "
462 						    "putwchar(%x)\n",
463 						    outline, outcol,
464 						    curscr->alines[outline]->line[outcol].wcols,
465 						    curscr->alines[outline]->line[outcol].ch);
466 					/*FALLTHROUGH*/
467 					case 0:
468 						break;
469 					default:
470 						goto nondes;
471 					}
472 				}
473 #endif /* HAVE_WCHAR */
474 				else
475 					goto nondes;
476 			}
477 		else
478 	nondes:	if (cursor_right)
479 			tputs(cursor_right, 0, plodput);
480 		else
481 			plodput(' ');
482 		outcol++;
483 		if (plodcnt < 0)
484 			goto out;
485 	}
486 
487 out:	if (plodflg) {
488 		outcol = soutcol;
489 		outline = soutline;
490 	}
491 	__CTRACE(__CTRACE_OUTPUT, "plod: returns %d\n", plodcnt);
492 	return plodcnt;
493 }
494 
495 /*
496  * Return the column number that results from being in column col and
497  * hitting a tab, where tabs are set every ts columns.  Work right for
498  * the case where col > COLS, even if ts does not divide COLS.
499  */
500 static int
501 tabcol(int col, int ts)
502 {
503 	int	 offset;
504 
505 	if (col >= COLS) {
506 		offset = COLS * (col / COLS);
507 		col -= offset;
508 	} else
509 		offset = 0;
510 	return (col + ts - (col % ts) + offset);
511 }
512