1/****************************************************************************
2 * Copyright 2020,2021 Thomas E. Dickey                                     *
3 * Copyright 2002-2011,2016 Free Software Foundation, Inc.                  *
4 *                                                                          *
5 * Permission is hereby granted, free of charge, to any person obtaining a  *
6 * copy of this software and associated documentation files (the            *
7 * "Software"), to deal in the Software without restriction, including      *
8 * without limitation the rights to use, copy, modify, merge, publish,      *
9 * distribute, distribute with modifications, sublicense, and/or sell       *
10 * copies of the Software, and to permit persons to whom the Software is    *
11 * furnished to do so, subject to the following conditions:                 *
12 *                                                                          *
13 * The above copyright notice and this permission notice shall be included  *
14 * in all copies or substantial portions of the Software.                   *
15 *                                                                          *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23 *                                                                          *
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25 * holders shall not be used in advertising or otherwise to promote the     *
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27 * authorization.                                                           *
28 ****************************************************************************/
29
30/****************************************************************************
31 *  Author: Thomas E. Dickey 2002-on                                        *
32 ****************************************************************************/
33
34/*
35**	lib_get_wch.c
36**
37**	The routine get_wch().
38**
39*/
40
41#include <curses.priv.h>
42#include <ctype.h>
43
44MODULE_ID("$Id: lib_get_wch.c,v 1.26 2021/04/17 16:12:54 tom Exp $")
45
46NCURSES_EXPORT(int)
47wget_wch(WINDOW *win, wint_t *result)
48{
49    SCREEN *sp;
50    int code;
51    int value = 0;
52#ifndef state_unused
53    mbstate_t state;
54#endif
55
56    T((T_CALLED("wget_wch(%p)"), (void *) win));
57
58    /*
59     * We can get a stream of single-byte characters and KEY_xxx codes from
60     * _nc_wgetch(), while we want to return a wide character or KEY_xxx code.
61     */
62    _nc_lock_global(curses);
63    sp = _nc_screen_of(win);
64
65    if (sp != 0) {
66	size_t count = 0;
67
68	for (;;) {
69	    char buffer[(MB_LEN_MAX * 9) + 1];	/* allow some redundant shifts */
70
71	    T(("reading %d of %d", (int) count + 1, (int) sizeof(buffer)));
72	    code = _nc_wgetch(win, &value, TRUE EVENTLIST_2nd((_nc_eventlist
73							       *) 0));
74	    if (code == ERR) {
75		break;
76	    } else if (code == KEY_CODE_YES) {
77		/*
78		 * If we were processing an incomplete multibyte character,
79		 * return an error since we have a KEY_xxx code which
80		 * interrupts it.  For some cases, we could improve this by
81		 * writing a new version of lib_getch.c(!), but it is not clear
82		 * whether the improvement would be worth the effort.
83		 */
84		if (count != 0) {
85		    safe_ungetch(SP_PARM, value);
86		    code = ERR;
87		}
88		break;
89	    } else if (count + 1 >= sizeof(buffer)) {
90		safe_ungetch(SP_PARM, value);
91		code = ERR;
92		break;
93	    } else {
94		int status;
95
96		buffer[count++] = (char) UChar(value);
97		reset_mbytes(state);
98		status = count_mbytes(buffer, count, state);
99		if (status >= 0) {
100		    wchar_t wch;
101		    reset_mbytes(state);
102		    if (check_mbytes(wch, buffer, count, state) != status) {
103			code = ERR;	/* the two calls should match */
104			safe_ungetch(SP_PARM, value);
105		    }
106		    value = wch;
107		    break;
108		}
109	    }
110	}
111    } else {
112	code = ERR;
113    }
114
115    if (result != 0)
116	*result = (wint_t) value;
117
118    _nc_unlock_global(curses);
119    T(("result %#o", value));
120    returnCode(code);
121}
122