xref: /netbsd/lib/libcurses/getch.c (revision bf9ec67e)
1 /*	$NetBSD: getch.c,v 1.36 2002/01/02 10:38:27 blymn 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)getch.c	8.2 (Berkeley) 5/4/94";
40 #else
41 __RCSID("$NetBSD: getch.c,v 1.36 2002/01/02 10:38:27 blymn Exp $");
42 #endif
43 #endif					/* not lint */
44 
45 #include <string.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <stdio.h>
49 #include "curses.h"
50 #include "curses_private.h"
51 
52 #define DEFAULT_DELAY 2			/* default delay for timeout() */
53 
54 /*
55  * Keyboard input handler.  Do this by snarfing
56  * all the info we can out of the termcap entry for TERM and putting it
57  * into a set of keymaps.  A keymap is an array the size of all the possible
58  * single characters we can get, the contents of the array is a structure
59  * that contains the type of entry this character is (i.e. part/end of a
60  * multi-char sequence or a plain char) and either a pointer which will point
61  * to another keymap (in the case of a multi-char sequence) OR the data value
62  * that this key should return.
63  *
64  */
65 
66 /* private data structures for holding the key definitions */
67 typedef struct key_entry key_entry_t;
68 
69 struct key_entry {
70 	short   type;		/* type of key this is */
71 	union {
72 		keymap_t *next;	/* next keymap is key is multi-key sequence */
73 		wchar_t   symbol;	/* key symbol if key is a leaf entry */
74 	} value;
75 };
76 /* Types of key structures we can have */
77 #define KEYMAP_MULTI  1		/* part of a multi char sequence */
78 #define KEYMAP_LEAF   2		/* key has a symbol associated with it, either
79 				 * it is the end of a multi-char sequence or a
80 				 * single char key that generates a symbol */
81 
82 /* allocate this many key_entry structs at once to speed start up must
83  * be a power of 2.
84  */
85 #define KEYMAP_ALLOC_CHUNK 4
86 
87 /* The max number of different chars we can receive */
88 #define MAX_CHAR 256
89 
90 struct keymap {
91 	int	count;		/* count of number of key structs allocated */
92 	short	mapping[MAX_CHAR]; /* mapping of key to allocated structs */
93 	key_entry_t **key;	/* dynamic array of keys */
94 };
95 
96 
97 /* Key buffer */
98 #define INBUF_SZ 16		/* size of key buffer - must be larger than
99 				 * longest multi-key sequence */
100 static wchar_t  inbuf[INBUF_SZ];
101 static int     start, end, working; /* pointers for manipulating inbuf data */
102 
103 #define INC_POINTER(ptr)  do {	\
104 	(ptr)++;		\
105 	ptr %= INBUF_SZ;	\
106 } while(/*CONSTCOND*/0)
107 
108 static short	state;		/* state of the inkey function */
109 
110 #define INKEY_NORM	 0	/* no key backlog to process */
111 #define INKEY_ASSEMBLING 1	/* assembling a multi-key sequence */
112 #define INKEY_BACKOUT	 2	/* recovering from an unrecognised key */
113 #define INKEY_TIMEOUT	 3	/* multi-key sequence timeout */
114 
115 /* The termcap data we are interested in and the symbols they map to */
116 struct tcdata {
117 	const char	*name;	/* name of termcap entry */
118 	wchar_t	symbol;		/* the symbol associated with it */
119 };
120 
121 static const struct tcdata tc[] = {
122 	{"!1", KEY_SSAVE},
123 	{"!2", KEY_SSUSPEND},
124 	{"!3", KEY_SUNDO},
125 	{"#1", KEY_SHELP},
126 	{"#2", KEY_SHOME},
127 	{"#3", KEY_SIC},
128 	{"#4", KEY_SLEFT},
129 	{"%0", KEY_REDO},
130 	{"%1", KEY_HELP},
131 	{"%2", KEY_MARK},
132 	{"%3", KEY_MESSAGE},
133 	{"%4", KEY_MOVE},
134 	{"%5", KEY_NEXT},
135 	{"%6", KEY_OPEN},
136 	{"%7", KEY_OPTIONS},
137 	{"%8", KEY_PREVIOUS},
138 	{"%9", KEY_PRINT},
139 	{"%a", KEY_SMESSAGE},
140 	{"%b", KEY_SMOVE},
141 	{"%c", KEY_SNEXT},
142 	{"%d", KEY_SOPTIONS},
143 	{"%e", KEY_SPREVIOUS},
144 	{"%f", KEY_SPRINT},
145 	{"%g", KEY_SREDO},
146 	{"%h", KEY_SREPLACE},
147 	{"%i", KEY_SRIGHT},
148 	{"%j", KEY_SRSUME},
149 	{"&0", KEY_SCANCEL},
150 	{"&1", KEY_REFERENCE},
151 	{"&2", KEY_REFRESH},
152 	{"&3", KEY_REPLACE},
153 	{"&4", KEY_RESTART},
154 	{"&5", KEY_RESUME},
155 	{"&6", KEY_SAVE},
156 	{"&7", KEY_SUSPEND},
157 	{"&8", KEY_UNDO},
158 	{"&9", KEY_SBEG},
159 	{"*0", KEY_SFIND},
160 	{"*1", KEY_SCOMMAND},
161 	{"*2", KEY_SCOPY},
162 	{"*3", KEY_SCREATE},
163 	{"*4", KEY_SDC},
164 	{"*5", KEY_SDL},
165 	{"*6", KEY_SELECT},
166 	{"*7", KEY_SEND},
167 	{"*8", KEY_SEOL},
168 	{"*9", KEY_SEXIT},
169 	{"@0", KEY_FIND},
170 	{"@1", KEY_BEG},
171 	{"@2", KEY_CANCEL},
172 	{"@3", KEY_CLOSE},
173 	{"@4", KEY_COMMAND},
174 	{"@5", KEY_COPY},
175 	{"@6", KEY_CREATE},
176 	{"@7", KEY_END},
177 	{"@8", KEY_ENTER},
178 	{"@9", KEY_EXIT},
179 	{"F1", KEY_F(11)},
180 	{"F2", KEY_F(12)},
181 	{"F3", KEY_F(13)},
182 	{"F4", KEY_F(14)},
183 	{"F5", KEY_F(15)},
184 	{"F6", KEY_F(16)},
185 	{"F7", KEY_F(17)},
186 	{"F8", KEY_F(18)},
187 	{"F9", KEY_F(19)},
188 	{"FA", KEY_F(20)},
189 	{"FB", KEY_F(21)},
190 	{"FC", KEY_F(22)},
191 	{"FD", KEY_F(23)},
192 	{"FE", KEY_F(24)},
193 	{"FF", KEY_F(25)},
194 	{"FG", KEY_F(26)},
195 	{"FH", KEY_F(27)},
196 	{"FI", KEY_F(28)},
197 	{"FJ", KEY_F(29)},
198 	{"FK", KEY_F(30)},
199 	{"FL", KEY_F(31)},
200 	{"FM", KEY_F(32)},
201 	{"FN", KEY_F(33)},
202 	{"FO", KEY_F(34)},
203 	{"FP", KEY_F(35)},
204 	{"FQ", KEY_F(36)},
205 	{"FR", KEY_F(37)},
206 	{"FS", KEY_F(38)},
207 	{"FT", KEY_F(39)},
208 	{"FU", KEY_F(40)},
209 	{"FV", KEY_F(41)},
210 	{"FW", KEY_F(42)},
211 	{"FX", KEY_F(43)},
212 	{"FY", KEY_F(44)},
213 	{"FZ", KEY_F(45)},
214 	{"Fa", KEY_F(46)},
215 	{"Fb", KEY_F(47)},
216 	{"Fc", KEY_F(48)},
217 	{"Fd", KEY_F(49)},
218 	{"Fe", KEY_F(50)},
219 	{"Ff", KEY_F(51)},
220 	{"Fg", KEY_F(52)},
221 	{"Fh", KEY_F(53)},
222 	{"Fi", KEY_F(54)},
223 	{"Fj", KEY_F(55)},
224 	{"Fk", KEY_F(56)},
225 	{"Fl", KEY_F(57)},
226 	{"Fm", KEY_F(58)},
227 	{"Fn", KEY_F(59)},
228 	{"Fo", KEY_F(60)},
229 	{"Fp", KEY_F(61)},
230 	{"Fq", KEY_F(62)},
231 	{"Fr", KEY_F(63)},
232 	{"K1", KEY_A1},
233 	{"K2", KEY_B2},
234 	{"K3", KEY_A3},
235 	{"K4", KEY_C1},
236 	{"K5", KEY_C3},
237 	{"Km", KEY_MOUSE},
238 	{"k0", KEY_F0},
239 	{"k1", KEY_F(1)},
240 	{"k2", KEY_F(2)},
241 	{"k3", KEY_F(3)},
242 	{"k4", KEY_F(4)},
243 	{"k5", KEY_F(5)},
244 	{"k6", KEY_F(6)},
245 	{"k7", KEY_F(7)},
246 	{"k8", KEY_F(8)},
247 	{"k9", KEY_F(9)},
248 	{"k;", KEY_F(10)},
249 	{"kA", KEY_IL},
250 	{"ka", KEY_CATAB},
251 	{"kB", KEY_BTAB},
252 	{"kb", KEY_BACKSPACE},
253 	{"kC", KEY_CLEAR},
254 	{"kD", KEY_DC},
255 	{"kd", KEY_DOWN},
256 	{"kE", KEY_EOL},
257 	{"kF", KEY_SF},
258 	{"kH", KEY_LL},
259 	{"kh", KEY_HOME},
260 	{"kI", KEY_IC},
261 	{"kL", KEY_DL},
262 	{"kl", KEY_LEFT},
263 	{"kM", KEY_EIC},
264 	{"kN", KEY_NPAGE},
265 	{"kP", KEY_PPAGE},
266 	{"kR", KEY_SR},
267 	{"kr", KEY_RIGHT},
268 	{"kS", KEY_EOS},
269 	{"kT", KEY_STAB},
270 	{"kt", KEY_CTAB},
271 	{"ku", KEY_UP}
272 };
273 /* Number of TC entries .... */
274 static const int num_tcs = (sizeof(tc) / sizeof(struct tcdata));
275 
276 /* prototypes for private functions */
277 static key_entry_t *add_new_key(keymap_t *current, char chr, int key_type,
278 				int symbol);
279 static keymap_t		*new_keymap(void);	/* create a new keymap */
280 static key_entry_t	*new_key(void);		/* create a new key entry */
281 static wchar_t		inkey(int to, int delay);
282 
283 /*
284  * Free the storage associated with the given keymap
285  */
286 void
287 _cursesi_free_keymap(keymap_t *map)
288 {
289 	int i;
290 
291 	  /* check for, and free, child keymaps */
292 	for (i = 0; i < MAX_CHAR; i++) {
293 		if (map->mapping[i] >= 0) {
294 			if (map->key[map->mapping[i]]->type == KEYMAP_MULTI)
295 				_cursesi_free_keymap(
296 					map->key[map->mapping[i]]->value.next);
297 		}
298 	}
299 
300 	  /* now free any allocated keymap structs */
301 	for (i = 0; i < map->count; i += KEYMAP_ALLOC_CHUNK) {
302 		free(map->key[i]);
303 	}
304 
305 	free(map->key);
306 	free(map);
307 }
308 
309 
310 /*
311  * Add a new key entry to the keymap pointed to by current.  Entry
312  * contains the character to add to the keymap, type is the type of
313  * entry to add (either multikey or leaf) and symbol is the symbolic
314  * value for a leaf type entry.  The function returns a pointer to the
315  * new keymap entry.
316  */
317 static key_entry_t *
318 add_new_key(keymap_t *current, char chr, int key_type, int symbol)
319 {
320 	key_entry_t *the_key;
321         int i;
322 
323 #ifdef DEBUG
324 	__CTRACE("Adding character %s of type %d, symbol 0x%x\n", unctrl(chr),
325 		 key_type, symbol);
326 #endif
327 	if (current->mapping[(unsigned char) chr] < 0) {
328 		  /* first time for this char */
329 		current->mapping[(unsigned char) chr] = current->count;	/* map new entry */
330 		  /* make sure we have room in the key array first */
331 		if ((current->count & (KEYMAP_ALLOC_CHUNK - 1)) == 0)
332 		{
333 			if ((current->key =
334 			     realloc(current->key,
335 				     (current->count) * sizeof(key_entry_t *)
336 				     + KEYMAP_ALLOC_CHUNK * sizeof(key_entry_t *))) == NULL) {
337 				fprintf(stderr,
338 					"Could not malloc for key entry\n");
339 				exit(1);
340 			}
341 
342 			the_key = new_key();
343                         for (i = 0; i < KEYMAP_ALLOC_CHUNK; i++) {
344                                 current->key[current->count + i]
345 					= &the_key[i];
346                         }
347                 }
348 
349                   /* point at the current key array element to use */
350                 the_key = current->key[current->count];
351 
352 		the_key->type = key_type;
353 
354 		switch (key_type) {
355 		  case KEYMAP_MULTI:
356 			    /* need for next key */
357 #ifdef DEBUG
358 			  __CTRACE("Creating new keymap\n");
359 #endif
360 			  the_key->value.next = new_keymap();
361 			  break;
362 
363 		  case KEYMAP_LEAF:
364 				/* the associated symbol for the key */
365 #ifdef DEBUG
366 			  __CTRACE("Adding leaf key\n");
367 #endif
368 			  the_key->value.symbol = symbol;
369 			  break;
370 
371 		  default:
372 			  fprintf(stderr, "add_new_key: bad type passed\n");
373 			  exit(1);
374 		}
375 
376 		current->count++;
377 	} else {
378 		  /* the key is already known - just return the address. */
379 #ifdef DEBUG
380 		__CTRACE("Keymap already known\n");
381 #endif
382 		the_key = current->key[current->mapping[(unsigned char) chr]];
383 	}
384 
385         return the_key;
386 }
387 
388 /*
389  * Init_getch - initialise all the pointers & structures needed to make
390  * getch work in keypad mode.
391  *
392  */
393 void
394 __init_getch(SCREEN *screen)
395 {
396 	char entry[1024], *p;
397 	int     i, j, length, key_ent;
398 	size_t limit;
399 	key_entry_t *tmp_key;
400 	keymap_t *current;
401 #ifdef DEBUG
402 	int k;
403 #endif
404 
405 	/* init the inkey state variable */
406 	state = INKEY_NORM;
407 
408 	/* init the base keymap */
409 	screen->base_keymap = new_keymap();
410 
411 	/* key input buffer pointers */
412 	start = end = working = 0;
413 
414 	/* now do the termcap snarfing ... */
415 
416 	for (i = 0; i < num_tcs; i++) {
417 		p = entry;
418 		limit = 1023;
419 		if (t_getstr(screen->cursesi_genbuf, tc[i].name,
420 			     &p, &limit) != NULL) {
421 			current = screen->base_keymap;	/* always start with
422 							 * base keymap. */
423 			length = (int) strlen(entry);
424 #ifdef DEBUG
425 			__CTRACE("Processing termcap entry %s, sequence ",
426 				 tc[i].name);
427 			for (k = 0; k <= length -1; k++)
428 				__CTRACE("%s", unctrl(entry[k]));
429 			__CTRACE("\n");
430 #endif
431 			for (j = 0; j < length - 1; j++) {
432 				  /* add the entry to the struct */
433 				tmp_key = add_new_key(current,
434 						      entry[j],
435 						      KEYMAP_MULTI, 0);
436 
437 				  /* index into the key array - it's
438 				     clearer if we stash this */
439 				key_ent = current->mapping[
440 					(unsigned char) entry[j]];
441 
442 				current->key[key_ent] = tmp_key;
443 
444 				  /* next key uses this map... */
445 				current = current->key[key_ent]->value.next;
446 			}
447 
448 				/* this is the last key in the sequence (it
449 				 * may have been the only one but that does
450 				 * not matter) this means it is a leaf key and
451 				 * should have a symbol associated with it.
452 				 */
453 			tmp_key = add_new_key(current,
454 					      entry[length - 1],
455 					      KEYMAP_LEAF,
456 					      tc[i].symbol);
457 			current->key[
458 				current->mapping[(int)entry[length - 1]]] =
459 			tmp_key;
460 		}
461 	}
462 }
463 
464 
465 /*
466  * new_keymap - allocates & initialises a new keymap structure.  This
467  * function returns a pointer to the new keymap.
468  *
469  */
470 static keymap_t *
471 new_keymap(void)
472 {
473 	int     i;
474 	keymap_t *new_map;
475 
476 	if ((new_map = malloc(sizeof(keymap_t))) == NULL) {
477 		perror("Inkey: Cannot allocate new keymap");
478 		exit(2);
479 	}
480 
481 	/* Initialise the new map */
482 	new_map->count = 0;
483 	for (i = 0; i < MAX_CHAR; i++) {
484 		new_map->mapping[i] = -1;	/* no mapping for char */
485 	}
486 
487 	/* key array will be allocated when first key is added */
488 	new_map->key = NULL;
489 
490 	return new_map;
491 }
492 
493 /*
494  * new_key - allocates & initialises a new key entry.  This function returns
495  * a pointer to the newly allocated key entry.
496  *
497  */
498 static key_entry_t *
499 new_key(void)
500 {
501 	key_entry_t *new_one;
502 	int i;
503 
504 	if ((new_one = malloc(KEYMAP_ALLOC_CHUNK * sizeof(key_entry_t)))
505 	    == NULL) {
506 		perror("inkey: Cannot allocate new key entry chunk");
507 		exit(2);
508 	}
509 
510 	for (i = 0; i < KEYMAP_ALLOC_CHUNK; i++) {
511 		new_one[i].type = 0;
512 		new_one[i].value.next = NULL;
513 	}
514 
515 	return new_one;
516 }
517 
518 /*
519  * inkey - do the work to process keyboard input, check for multi-key
520  * sequences and return the appropriate symbol if we get a match.
521  *
522  */
523 
524 wchar_t
525 inkey(int to, int delay)
526 {
527 	wchar_t		 k;
528 	int              c;
529 	keymap_t	*current = _cursesi_screen->base_keymap;
530 	FILE            *infd = _cursesi_screen->infd;
531 
532 	k = 0;		/* XXX gcc -Wuninitialized */
533 
534 	for (;;) {		/* loop until we get a complete key sequence */
535 reread:
536 		if (state == INKEY_NORM) {
537 			if (delay && __timeout(delay) == ERR)
538 				return ERR;
539 			if ((c = getchar()) == EOF) {
540 				clearerr(infd);
541 				return ERR;
542 			}
543 
544 			if (delay && (__notimeout() == ERR))
545 				return ERR;
546 
547 			k = (wchar_t) c;
548 #ifdef DEBUG
549 			__CTRACE("inkey (state normal) got '%s'\n", unctrl(k));
550 #endif
551 
552 			working = start;
553 			inbuf[working] = k;
554 			INC_POINTER(working);
555 			end = working;
556 			state = INKEY_ASSEMBLING;	/* go to the assembling
557 							 * state now */
558 		} else if (state == INKEY_BACKOUT) {
559 			k = inbuf[working];
560 			INC_POINTER(working);
561 			if (working == end) {	/* see if we have run
562 						 * out of keys in the
563 						 * backlog */
564 
565 				/* if we have then switch to
566 				   assembling */
567 				state = INKEY_ASSEMBLING;
568 			}
569 		} else if (state == INKEY_ASSEMBLING) {
570 			/* assembling a key sequence */
571 			if (delay) {
572 				if (__timeout(to ? DEFAULT_DELAY : delay) == ERR)
573 						return ERR;
574 			} else {
575 				if (to && (__timeout(DEFAULT_DELAY) == ERR))
576 					return ERR;
577 			}
578 
579 			c = getchar();
580 			if (ferror(infd)) {
581 				clearerr(infd);
582 				return ERR;
583 			}
584 
585 			if ((to || delay) && (__notimeout() == ERR))
586 					return ERR;
587 
588 			k = (wchar_t) c;
589 #ifdef DEBUG
590 			__CTRACE("inkey (state assembling) got '%s'\n", unctrl(k));
591 #endif
592 			if (feof(infd)) {	/* inter-char timeout,
593 						 * start backing out */
594 				clearerr(infd);
595 				if (start == end)
596 					/* no chars in the buffer, restart */
597 					goto reread;
598 
599 				k = inbuf[start];
600 				state = INKEY_TIMEOUT;
601 			} else {
602 				inbuf[working] = k;
603 				INC_POINTER(working);
604 				end = working;
605 			}
606 		} else {
607 			fprintf(stderr, "Inkey state screwed - exiting!!!");
608 			exit(2);
609 		}
610 
611 		/* Check key has no special meaning and we have not timed out */
612 		if ((state == INKEY_TIMEOUT) || (current->mapping[k] < 0)) {
613 			/* return the first key we know about */
614 			k = inbuf[start];
615 
616 			INC_POINTER(start);
617 			working = start;
618 
619 			if (start == end) {	/* only one char processed */
620 				state = INKEY_NORM;
621 			} else {/* otherwise we must have more than one char
622 				 * to backout */
623 				state = INKEY_BACKOUT;
624 			}
625 			return k;
626 		} else {	/* must be part of a multikey sequence */
627 			/* check for completed key sequence */
628 			if (current->key[current->mapping[k]]->type == KEYMAP_LEAF) {
629 				start = working;	/* eat the key sequence
630 							 * in inbuf */
631 
632 				/* check if inbuf empty now */
633 				if (start == end) {
634 					/* if it is go back to normal */
635 					state = INKEY_NORM;
636 				} else {
637 					/* otherwise go to backout state */
638 					state = INKEY_BACKOUT;
639 				}
640 
641 				/* return the symbol */
642 				return current->key[current->mapping[k]]->value.symbol;
643 
644 			} else {
645 				/*
646 				 * Step on to next part of the multi-key
647 				 * sequence.
648 				 */
649 				current = current->key[current->mapping[k]]->value.next;
650 			}
651 		}
652 	}
653 }
654 
655 #ifndef _CURSES_USE_MACROS
656 /*
657  * getch --
658  *	Read in a character from stdscr.
659  */
660 int
661 getch(void)
662 {
663 	return wgetch(stdscr);
664 }
665 
666 /*
667  * mvgetch --
668  *      Read in a character from stdscr at the given location.
669  */
670 int
671 mvgetch(int y, int x)
672 {
673 	return mvwgetch(stdscr, y, x);
674 }
675 
676 /*
677  * mvwgetch --
678  *      Read in a character from stdscr at the given location in the
679  *      given window.
680  */
681 int
682 mvwgetch(WINDOW *win, int y, int x)
683 {
684 	if (wmove(win, y, x) == ERR)
685 		return ERR;
686 
687 	return wgetch(win);
688 }
689 
690 #endif
691 
692 /*
693  * wgetch --
694  *	Read in a character from the window.
695  */
696 int
697 wgetch(WINDOW *win)
698 {
699 	int inp, weset;
700 	int c;
701 	FILE *infd = _cursesi_screen->infd;
702 
703 	if (!(win->flags & __SCROLLOK) && (win->flags & __FULLWIN)
704 	    && win->curx == win->maxx - 1 && win->cury == win->maxy - 1
705 	    && __echoit)
706 		return (ERR);
707 
708 	if (is_wintouched(win))
709 		wrefresh(win);
710 #ifdef DEBUG
711 	__CTRACE("wgetch: __echoit = %d, __rawmode = %d, flags = %0.2o\n",
712 	    __echoit, __rawmode, win->flags);
713 #endif
714 	if (__echoit && !__rawmode) {
715 		cbreak();
716 		weset = 1;
717 	} else
718 		weset = 0;
719 
720 	__save_termios();
721 
722 	if (win->flags & __KEYPAD) {
723 		switch (win->delay)
724 		{
725 		case -1:
726 			inp = inkey (win->flags & __NOTIMEOUT ? 0 : 1, 0);
727 			break;
728 		case 0:
729 			if (__nodelay() == ERR) {
730 				__restore_termios();
731 				return ERR;
732 			}
733 			inp = inkey(0, 0);
734 			break;
735 		default:
736 			inp = inkey(win->flags & __NOTIMEOUT ? 0 : 1, win->delay);
737 			break;
738 		}
739 	} else {
740 		switch (win->delay)
741 		{
742 		case -1:
743 			break;
744 		case 0:
745 			if (__nodelay() == ERR) {
746 				__restore_termios();
747 				return ERR;
748 			}
749 			break;
750 		default:
751 			if (__timeout(win->delay) == ERR) {
752 				__restore_termios();
753 				return ERR;
754 			}
755 			break;
756 		}
757 
758 		c = getchar();
759 		if (feof(infd)) {
760 			clearerr(infd);
761 			__restore_termios();
762 			return ERR;	/* we have timed out */
763 		}
764 
765 		if (ferror(infd)) {
766 			clearerr(infd);
767 			inp = ERR;
768 		} else {
769 			inp = c;
770 		}
771 	}
772 #ifdef DEBUG
773 	if (inp > 255)
774 		  /* we have a key symbol - treat it differently */
775 		  /* XXXX perhaps __unctrl should be expanded to include
776 		   * XXXX the keysyms in the table....
777 		   */
778 		__CTRACE("wgetch assembled keysym 0x%x\n", inp);
779 	else
780 		__CTRACE("wgetch got '%s'\n", unctrl(inp));
781 #endif
782 	if (win->delay > -1) {
783 		if (__delay() == ERR) {
784 			__restore_termios();
785 			return ERR;
786 		}
787 	}
788 
789 	__restore_termios();
790 
791 	if (__echoit)
792 		waddch(win, (chtype) inp);
793 
794 	if (weset)
795 		nocbreak();
796 
797 	return ((inp < 0) || (inp == ERR) ? ERR : inp);
798 }
799 
800 /*
801  * ungetch --
802  *     Put the character back into the input queue.
803  */
804 int
805 ungetch(int c)
806 {
807 	return ((ungetc(c, _cursesi_screen->infd) == EOF) ? ERR : OK);
808 }
809