1 /* $OpenBSD: lib_get_wch.c,v 1.2 2023/10/17 09:52:09 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright 2020,2021 Thomas E. Dickey                                     *
5  * Copyright 2002-2011,2016 Free Software Foundation, Inc.                  *
6  *                                                                          *
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8  * copy of this software and associated documentation files (the            *
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11  * distribute, distribute with modifications, sublicense, and/or sell       *
12  * copies of the Software, and to permit persons to whom the Software is    *
13  * furnished to do so, subject to the following conditions:                 *
14  *                                                                          *
15  * The above copyright notice and this permission notice shall be included  *
16  * in all copies or substantial portions of the Software.                   *
17  *                                                                          *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
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31 
32 /****************************************************************************
33  *  Author: Thomas E. Dickey 2002-on                                        *
34  ****************************************************************************/
35 
36 /*
37 **	lib_get_wch.c
38 **
39 **	The routine get_wch().
40 **
41 */
42 
43 #include <curses.priv.h>
44 #include <ctype.h>
45 
46 MODULE_ID("$Id: lib_get_wch.c,v 1.2 2023/10/17 09:52:09 nicm Exp $")
47 
48 NCURSES_EXPORT(int)
49 wget_wch(WINDOW *win, wint_t *result)
50 {
51     SCREEN *sp;
52     int code;
53     int value = 0;
54 #ifndef state_unused
55     mbstate_t state;
56 #endif
57 
58     T((T_CALLED("wget_wch(%p)"), (void *) win));
59 
60     /*
61      * We can get a stream of single-byte characters and KEY_xxx codes from
62      * _nc_wgetch(), while we want to return a wide character or KEY_xxx code.
63      */
64     _nc_lock_global(curses);
65     sp = _nc_screen_of(win);
66 
67     if (sp != 0) {
68 	size_t count = 0;
69 
70 	for (;;) {
71 	    char buffer[(MB_LEN_MAX * 9) + 1];	/* allow some redundant shifts */
72 
73 	    T(("reading %d of %d", (int) count + 1, (int) sizeof(buffer)));
74 	    code = _nc_wgetch(win, &value, TRUE EVENTLIST_2nd((_nc_eventlist
75 							       *) 0));
76 	    if (code == ERR) {
77 		break;
78 	    } else if (code == KEY_CODE_YES) {
79 		/*
80 		 * If we were processing an incomplete multibyte character,
81 		 * return an error since we have a KEY_xxx code which
82 		 * interrupts it.  For some cases, we could improve this by
83 		 * writing a new version of lib_getch.c(!), but it is not clear
84 		 * whether the improvement would be worth the effort.
85 		 */
86 		if (count != 0) {
87 		    safe_ungetch(SP_PARM, value);
88 		    code = ERR;
89 		}
90 		break;
91 	    } else if (count + 1 >= sizeof(buffer)) {
92 		safe_ungetch(SP_PARM, value);
93 		code = ERR;
94 		break;
95 	    } else {
96 		int status;
97 
98 		buffer[count++] = (char) UChar(value);
99 		reset_mbytes(state);
100 		status = count_mbytes(buffer, count, state);
101 		if (status >= 0) {
102 		    wchar_t wch;
103 		    reset_mbytes(state);
104 		    if (check_mbytes(wch, buffer, count, state) != status) {
105 			code = ERR;	/* the two calls should match */
106 			safe_ungetch(SP_PARM, value);
107 		    }
108 		    value = wch;
109 		    break;
110 		}
111 	    }
112 	}
113     } else {
114 	code = ERR;
115     }
116 
117     if (result != 0)
118 	*result = (wint_t) value;
119 
120     _nc_unlock_global(curses);
121     T(("result %#o", value));
122     returnCode(code);
123 }
124