xref: /netbsd-src/lib/libcurses/get_wch.c (revision 6348e3f32a4431b45d07e1da16fd7b12725a45e7)
1 /*   $NetBSD: get_wch.c,v 1.28 2024/12/23 02:58:03 blymn Exp $ */
2 
3 /*
4  * Copyright (c) 2005 The NetBSD Foundation Inc.
5  * All rights reserved.
6  *
7  * This code is derived from code donated to the NetBSD Foundation
8  * by Ruibiao Qiu <ruibiao@arl.wustl.edu,ruibiao@gmail.com>.
9  *
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *	notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *	notice, this list of conditions and the following disclaimer in the
18  *	documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the NetBSD Foundation nor the names of its
20  *	contributors may be used to endorse or promote products derived
21  *	from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND
24  * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #ifndef lint
39 __RCSID("$NetBSD: get_wch.c,v 1.28 2024/12/23 02:58:03 blymn Exp $");
40 #endif						  /* not lint */
41 
42 #include <errno.h>
43 #include <string.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include <stdio.h>
47 #include "curses.h"
48 #include "curses_private.h"
49 #include "keymap.h"
50 
51 static short wstate;		/* state of the wcinkey function */
52 extern short _cursesi_state;	/* storage declared in getch.c */
53 
54 /* prototypes for private functions */
55 static int inkey(wchar_t *wc, int to, int delay);
56 static wint_t __fgetwc_resize(FILE *infd, bool *resized);
57 
58 /*
59  * __init_get_wch - initialise all the pointers & structures needed to make
60  * get_wch work in keypad mode.
61  *
62  */
63 void
64 __init_get_wch(SCREEN *screen)
65 {
66 	wstate = INKEY_NORM;
67 	memset(&screen->cbuf, 0, sizeof(screen->cbuf));
68 	screen->cbuf_head = screen->cbuf_tail = screen->cbuf_cur = 0;
69 }
70 
71 
72 /*
73  * inkey - do the work to process keyboard input, check for multi-key
74  * sequences and return the appropriate symbol if we get a match.
75  *
76  */
77 static int
78 inkey(wchar_t *wc, int to, int delay)
79 {
80 	wchar_t		 k = 0;
81 	int		 c, mapping, ret = 0;
82 	size_t	  mlen = 0;
83 	keymap_t	*current = _cursesi_screen->base_keymap;
84 	FILE		*infd = _cursesi_screen->infd;
85 	int		 *start = &_cursesi_screen->cbuf_head,
86 				*working = &_cursesi_screen->cbuf_cur,
87 				*end = &_cursesi_screen->cbuf_tail;
88 	char		*inbuf = &_cursesi_screen->cbuf[ 0 ];
89 
90 	__CTRACE(__CTRACE_INPUT, "inkey (%p, %d, %d)\n", wc, to, delay);
91 	for (;;) { /* loop until we get a complete key sequence */
92 		if (wstate == INKEY_NORM) {
93 			if (delay && __timeout(delay) == ERR)
94 				return ERR;
95 			c = __fgetc_resize(infd);
96 			if (c == ERR || c == KEY_RESIZE) {
97 				clearerr(infd);
98 				return c;
99 			}
100 
101 			if (delay && (__notimeout() == ERR))
102 				return ERR;
103 
104 			k = (wchar_t)c;
105 			__CTRACE(__CTRACE_INPUT,
106 			    "inkey (wstate normal) got '%s'\n", unctrl(k));
107 
108 			inbuf[*end] = k;
109 			*end = (*end + 1) % MAX_CBUF_SIZE;
110 			*working = *start;
111 			wstate = INKEY_ASSEMBLING; /* go to assembling state */
112 			__CTRACE(__CTRACE_INPUT,
113 			    "inkey: NORM=>ASSEMBLING: start(%d), "
114 			    "current(%d), end(%d)\n", *start, *working, *end);
115 		} else if (wstate == INKEY_BACKOUT) {
116 			k = inbuf[*working];
117 			*working = (*working + 1) % MAX_CBUF_SIZE;
118 			if (*working == *end) {	/* see if run out of keys */
119 				/* if so, switch to assembling */
120 				wstate = INKEY_ASSEMBLING;
121 				__CTRACE(__CTRACE_INPUT,
122 				    "inkey: BACKOUT=>ASSEMBLING, start(%d), "
123 				    "current(%d), end(%d)\n",
124 				    *start, *working, *end);
125 			}
126 		} else if (wstate == INKEY_ASSEMBLING) {
127 			/* assembling a key sequence */
128 			if (delay) {
129 				if (__timeout(to ? (ESCDELAY / 100) : delay)
130 						== ERR)
131 					return ERR;
132 			} else {
133 				if (to && (__timeout(ESCDELAY / 100) == ERR))
134 					return ERR;
135 			}
136 
137 			c = __fgetc_resize(infd);
138 			if (c == ERR || ferror(infd)) {
139 				clearerr(infd);
140 				return c;
141 			}
142 
143 			if ((to || delay) && (__notimeout() == ERR))
144 				return ERR;
145 
146 			k = (wchar_t)c;
147 			__CTRACE(__CTRACE_INPUT,
148 			    "inkey (wstate assembling) got '%s'\n", unctrl(k));
149 			if (feof(infd)) { /* inter-char T/O, start backout */
150 				clearerr(infd);
151 				if (*start == *end)
152 					/* no chars in the buffer, restart */
153 					continue;
154 
155 				k = inbuf[*start];
156 				wstate = INKEY_TIMEOUT;
157 				__CTRACE(__CTRACE_INPUT,
158 				    "inkey: ASSEMBLING=>TIMEOUT, start(%d), "
159 				    "current(%d), end(%d)\n",
160 				    *start, *working, *end);
161 			} else {
162 				inbuf[*end] = k;
163 				*working = *end;
164 				*end = (*end + 1) % MAX_CBUF_SIZE;
165 				__CTRACE(__CTRACE_INPUT,
166 				    "inkey: ASSEMBLING: start(%d), "
167 				    "current(%d), end(%d)",
168 				    *start, *working, *end);
169 			}
170 		} else if (wstate == INKEY_WCASSEMBLING) {
171 			/* assembling a wide-char sequence */
172 			if (delay) {
173 				if (__timeout(to ? (ESCDELAY / 100) : delay)
174 						== ERR)
175 					return ERR;
176 			} else {
177 				if (to && (__timeout(ESCDELAY / 100) == ERR))
178 					return ERR;
179 			}
180 
181 			c = __fgetc_resize(infd);
182 			if (c == ERR || ferror(infd)) {
183 				clearerr(infd);
184 				return c;
185 			}
186 
187 			if ((to || delay) && (__notimeout() == ERR))
188 				return ERR;
189 
190 			k = (wchar_t)c;
191 			__CTRACE(__CTRACE_INPUT,
192 			    "inkey (wstate wcassembling) got '%s'\n",
193 			    unctrl(k));
194 			if (feof(infd)) { /* inter-char T/O, start backout */
195 				clearerr(infd);
196 				if (*start == *end)
197 					/* no chars in the buffer, restart */
198 					continue;
199 
200 				*wc = inbuf[*start];
201 				*working = *start = (*start +1) % MAX_CBUF_SIZE;
202 				if (*start == *end) {
203 					_cursesi_state = wstate = INKEY_NORM;
204 					__CTRACE(__CTRACE_INPUT,
205 					    "inkey: WCASSEMBLING=>NORM, "
206 					    "start(%d), current(%d), end(%d)",
207 					    *start, *working, *end);
208 				} else {
209 					_cursesi_state = wstate = INKEY_BACKOUT;
210 					__CTRACE(__CTRACE_INPUT,
211 					    "inkey: WCASSEMBLING=>BACKOUT, "
212 					    "start(%d), current(%d), end(%d)",
213 					    *start, *working, *end);
214 				}
215 				return OK;
216 			} else {
217 				/* assembling wide characters */
218 				inbuf[*end] = k;
219 				*working = *end;
220 				*end = (*end + 1) % MAX_CBUF_SIZE;
221 				__CTRACE(__CTRACE_INPUT,
222 				    "inkey: WCASSEMBLING[head(%d), "
223 				    "urrent(%d), tail(%d)]\n",
224 				    *start, *working, *end);
225 				ret = (int)mbrtowc(wc, inbuf + (*working), 1,
226 						   &_cursesi_screen->sp);
227 				__CTRACE(__CTRACE_INPUT,
228 				    "inkey: mbrtowc returns %d, wc(%x)\n",
229 				    ret, *wc);
230 				if (ret == -2) {
231 					*working = (*working+1) % MAX_CBUF_SIZE;
232 					continue;
233 				}
234 				if ( ret == 0 )
235 					ret = 1;
236 				if ( ret == -1 ) {
237 					/* return the 1st character we know */
238 					*wc = inbuf[*start];
239 					*working = *start =
240 					    (*start + 1) % MAX_CBUF_SIZE;
241 					__CTRACE(__CTRACE_INPUT,
242 					    "inkey: Invalid wide char(%x) "
243 					    "[head(%d), current(%d), "
244 					    "tail(%d)]\n",
245 					    *wc, *start, *working, *end);
246 				} else { /* > 0 */
247 					/* return the wide character */
248 					*start = *working =
249 					    (*working + ret) % MAX_CBUF_SIZE;
250 					__CTRACE(__CTRACE_INPUT,
251 					    "inkey: Wide char found(%x) "
252 					    "[head(%d), current(%d), "
253 					    "tail(%d)]\n",
254 					    *wc, *start, *working, *end);
255 				}
256 
257 				if (*start == *end) {
258 					/* only one char processed */
259 					_cursesi_state = wstate = INKEY_NORM;
260 					__CTRACE(__CTRACE_INPUT,
261 					    "inkey: WCASSEMBLING=>NORM, "
262 					    "start(%d), current(%d), end(%d)",
263 					    *start, *working, *end);
264 				} else {
265 					/* otherwise we must have more than
266 					 * one char to backout */
267 					_cursesi_state = wstate = INKEY_BACKOUT;
268 					__CTRACE(__CTRACE_INPUT,
269 					    "inkey: WCASSEMBLING=>BACKOUT, "
270 					    "start(%d), current(%d), end(%d)",
271 					    *start, *working, *end);
272 				}
273 				return OK;
274 			}
275 		} else {
276 			fprintf(stderr, "Inkey wstate screwed - exiting!!!");
277 			exit(2);
278 		}
279 
280 		/*
281 		 * Check key has no special meaning and we have not
282 		 * timed out and the key has not been disabled
283 		 */
284 		mapping = current->mapping[k];
285 		if (((wstate == INKEY_TIMEOUT) || (mapping < 0))
286 				|| ((current->key[mapping]->type
287 					== KEYMAP_LEAF)
288 				&& (current->key[mapping]->enable == FALSE)))
289 		{
290 			/* wide-character specific code */
291 			__CTRACE(__CTRACE_INPUT,
292 			    "inkey: Checking for wide char\n");
293 			mbrtowc(NULL, NULL, 1, &_cursesi_screen->sp);
294 			*working = *start;
295 			mlen = *end > *working ?
296 				*end - *working : MAX_CBUF_SIZE - *working;
297 			if (!mlen)
298 				return ERR;
299 			__CTRACE(__CTRACE_INPUT,
300 			    "inkey: Check wide char[head(%d), "
301 			    "current(%d), tail(%d), mlen(%zu)]\n",
302 			    *start, *working, *end, mlen);
303 			ret = (int)mbrtowc(wc, inbuf + (*working), mlen,
304 			                   &_cursesi_screen->sp);
305 			__CTRACE(__CTRACE_INPUT,
306 			    "inkey: mbrtowc returns %d, wc(%x)\n", ret, *wc);
307 			if (ret == -2 && *end < *working) {
308 				/* second half of a wide character */
309 				*working = 0;
310 				mlen = *end;
311 				if (mlen)
312 					ret = (int)mbrtowc(wc, inbuf, mlen,
313 							  &_cursesi_screen->sp);
314 			}
315 			if (ret == -2 && wstate != INKEY_TIMEOUT) {
316 				*working =
317 				    (*working + (int) mlen) % MAX_CBUF_SIZE;
318 				wstate = INKEY_WCASSEMBLING;
319 				continue;
320 			}
321 			if (ret == 0)
322 				ret = 1;
323 			if (ret == -1) {
324 				/* return the first key we know about */
325 				*wc = inbuf[*start];
326 				*working = *start =
327 				    (*start + 1) % MAX_CBUF_SIZE;
328 				__CTRACE(__CTRACE_INPUT,
329 				    "inkey: Invalid wide char(%x)[head(%d), "
330 				    "current(%d), tail(%d)]\n",
331 				    *wc, *start, *working, *end);
332 			} else { /* > 0 */
333 				/* return the wide character */
334 				*start = *working =
335 				    (*working + ret) % MAX_CBUF_SIZE;
336 				__CTRACE(__CTRACE_INPUT,
337 				    "inkey: Wide char found(%x)[head(%d), "
338 				    "current(%d), tail(%d)]\n",
339 				    *wc, *start, *working, *end);
340 			}
341 
342 			if (*start == *end) {	/* only one char processed */
343 				_cursesi_state = wstate = INKEY_NORM;
344 				__CTRACE(__CTRACE_INPUT,
345 				    "inkey: Empty cbuf=>NORM, "
346 				    "start(%d), current(%d), end(%d)\n",
347 				    *start, *working, *end);
348 			} else {
349 				/* otherwise we must have more than one
350 				 * char to backout */
351 				_cursesi_state = wstate = INKEY_BACKOUT;
352 				__CTRACE(__CTRACE_INPUT,
353 				    "inkey: Non-empty cbuf=>BACKOUT, "
354 				    "start(%d), current(%d), end(%d)\n",
355 				    *start, *working, *end);
356 			}
357 			return OK;
358 		} else {	/* must be part of a multikey sequence */
359 					/* check for completed key sequence */
360 			if (current->key[current->mapping[k]]->type
361 					== KEYMAP_LEAF) {
362 				/* eat the key sequence in cbuf */
363 				*start = *working =
364 				    (*working + 1) % MAX_CBUF_SIZE;
365 
366 				/* check if inbuf empty now */
367 				__CTRACE(__CTRACE_INPUT,
368 				    "inkey: Key found(%s)\n",
369 				    key_name(current->key[mapping]->value.symbol));
370 				if (*start == *end) {
371 					/* if it is go back to normal */
372 					_cursesi_state = wstate = INKEY_NORM;
373 					__CTRACE(__CTRACE_INPUT,
374 					    "[inkey]=>NORM, start(%d), "
375 					    "current(%d), end(%d)",
376 					    *start, *working, *end);
377 				} else {
378 					/* otherwise go to backout state */
379 					_cursesi_state = wstate = INKEY_BACKOUT;
380 					__CTRACE(__CTRACE_INPUT,
381 					    "[inkey]=>BACKOUT, start(%d), "
382 					    "current(%d), end(%d)",
383 					    *start, *working, *end);
384 				}
385 
386 				/* return the symbol */
387 				*wc = current->key[mapping]->value.symbol;
388 				return KEY_CODE_YES;
389 			} else {
390 				/* Step to next part of multi-key sequence */
391 				current = current->key[current->mapping[k]]->value.next;
392 			}
393 		}
394 	}
395 }
396 
397 /*
398  * get_wch --
399  *	Read in a wide character from stdscr.
400  */
401 int
402 get_wch(wint_t *ch)
403 {
404 	return wget_wch(stdscr, ch);
405 }
406 
407 /*
408  * mvget_wch --
409  *	  Read in a character from stdscr at the given location.
410  */
411 int
412 mvget_wch(int y, int x, wint_t *ch)
413 {
414 	return mvwget_wch(stdscr, y, x, ch);
415 }
416 
417 /*
418  * mvwget_wch --
419  *	  Read in a character from stdscr at the given location in the
420  *	  given window.
421  */
422 int
423 mvwget_wch(WINDOW *win, int y, int x, wint_t *ch)
424 {
425 	if (wmove(win, y, x) == ERR)
426 		return ERR;
427 
428 	return wget_wch(win, ch);
429 }
430 
431 /*
432  * wget_wch --
433  *	Read in a wide character from the window.
434  */
435 int
436 wget_wch(WINDOW *win, wint_t *ch)
437 {
438 	int ret, weset;
439 	int c;
440 	FILE *infd = _cursesi_screen->infd;
441 	cchar_t wc;
442 	wchar_t inp, ws[2];
443 
444 	if (__predict_false(win == NULL))
445 		return ERR;
446 
447 	if (!(win->flags & __SCROLLOK)
448 	    && (win->flags & __FULLWIN)
449 	    && win->curx == win->maxx - 1
450 	    && win->cury == win->maxy - 1
451 	    && __echoit)
452 		return ERR;
453 
454 	if (!(win->flags & __ISPAD) && is_wintouched(win))
455 		wrefresh(win);
456 	__CTRACE(__CTRACE_INPUT, "wget_wch: __echoit = %d, "
457 	    "__rawmode = %d, __nl = %d, flags = %#.4x\n",
458 	    __echoit, __rawmode, _cursesi_screen->nl, win->flags);
459 	if (_cursesi_screen->resized) {
460 		resizeterm(LINES, COLS);
461 		_cursesi_screen->resized = 0;
462 		*ch = KEY_RESIZE;
463 		return KEY_CODE_YES;
464 	}
465 	if (_cursesi_screen->unget_pos) {
466 		__CTRACE(__CTRACE_INPUT, "wget_wch returning char at %d\n",
467 		    _cursesi_screen->unget_pos);
468 		_cursesi_screen->unget_pos--;
469 		*ch = _cursesi_screen->unget_list[_cursesi_screen->unget_pos];
470 		if (__echoit) {
471 			ws[0] = *ch, ws[1] = L'\0';
472 			setcchar(&wc, ws, win->wattr, 0, NULL);
473 			wadd_wch(win, &wc);
474 		}
475 		return KEY_CODE_YES;
476 	}
477 	if (__echoit && !__rawmode) {
478 		cbreak();
479 		weset = 1;
480 	} else
481 		weset = 0;
482 
483 	__save_termios();
484 
485 	if (win->flags & __KEYPAD) {
486 		switch (win->delay) {
487 			case -1:
488 				ret = inkey(&inp,
489 					win->flags & __NOTIMEOUT ? 0 : 1, 0);
490 				break;
491 			case 0:
492 				if (__nodelay() == ERR)
493 					return ERR;
494 				ret = inkey(&inp, 0, 0);
495 				break;
496 			default:
497 				ret = inkey(&inp,
498 					win->flags & __NOTIMEOUT ? 0 : 1,
499 					win->delay);
500 				break;
501 		}
502 		if ( ret == ERR )
503 			return ERR;
504 	} else {
505 		bool resized;
506 
507 		switch (win->delay) {
508 			case -1:
509 				break;
510 			case 0:
511 				if (__nodelay() == ERR)
512 					return ERR;
513 				break;
514 			default:
515 				if (__timeout(win->delay) == ERR)
516 					return ERR;
517 				break;
518 		}
519 
520 		c = __fgetwc_resize(infd, &resized);
521 		if (c == WEOF) {
522 			clearerr(infd);
523 			__restore_termios();
524 			if (resized) {
525 				*ch = KEY_RESIZE;
526 				return KEY_CODE_YES;
527 			} else
528 				return ERR;
529 		} else {
530 			ret = c;
531 			inp = c;
532 		}
533 	}
534 #ifdef DEBUG
535 	if (inp > 255)
536 		/* we have a key symbol - treat it differently */
537 		/* XXXX perhaps __unctrl should be expanded to include
538 		 * XXXX the keysyms in the table....
539 		 */
540 		__CTRACE(__CTRACE_INPUT, "wget_wch assembled keysym 0x%x\n",
541 		    inp);
542 	else
543 		__CTRACE(__CTRACE_INPUT, "wget_wch got '%s'\n", unctrl(inp));
544 #endif
545 	if (win->delay > -1) {
546 		if (__delay() == ERR)
547 			return ERR;
548 	}
549 
550 	__restore_termios();
551 
552 	if (__echoit) {
553 		if ( ret == KEY_CODE_YES ) {
554 			/* handle [DEL], [BS], and [LEFT] */
555 			if ( win->curx &&
556 					( inp == KEY_DC ||
557 					  inp == KEY_BACKSPACE ||
558 					  inp == KEY_LEFT )) {
559 				wmove( win, win->cury, win->curx - 1);
560 				wdelch( win );
561 			}
562 		} else {
563 			ws[ 0 ] = inp, ws[ 1 ] = L'\0';
564 			setcchar( &wc, ws, win->wattr, 0, NULL );
565 			wadd_wch( win, &wc );
566 		}
567 	}
568 
569 	if (weset)
570 		nocbreak();
571 
572 	if (_cursesi_screen->nl && inp == 13)
573 		inp = 10;
574 
575 	*ch = inp;
576 
577 	if ( ret == KEY_CODE_YES )
578 		return KEY_CODE_YES;
579 	return inp < 0 ? ERR : OK;
580 }
581 
582 /*
583  * unget_wch --
584  *	 Put the wide character back into the input queue.
585  */
586 int
587 unget_wch(const wchar_t c)
588 {
589 	return __unget((wint_t)c);
590 }
591 
592 /*
593  * __fgetwc_resize --
594  *    Any call to fgetwc(3) should use this function instead.
595  */
596 static wint_t
597 __fgetwc_resize(FILE *infd, bool *resized)
598 {
599 	wint_t c;
600 
601 	c = fgetwc(infd);
602 	if (c != WEOF)
603 		return c;
604 
605 	if (!ferror(infd) || errno != EINTR || !_cursesi_screen->resized)
606 		return ERR;
607 	__CTRACE(__CTRACE_INPUT, "__fgetwc_resize returning KEY_RESIZE\n");
608 	resizeterm(LINES, COLS);
609 	_cursesi_screen->resized = 0;
610 	*resized = true;
611 	return c;
612 }
613