xref: /openbsd-src/lib/libcurses/widechar/lib_get_wch.c (revision 6bc6570d7fd20fe27f87e204c2ecf395c194fff8)
1 /* $OpenBSD: lib_get_wch.c,v 1.1 2010/09/06 17:26:17 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright (c) 2002-2007,2008 Free Software Foundation, Inc.              *
5  *                                                                          *
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7  * copy of this software and associated documentation files (the            *
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11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
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15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
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19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
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30 
31 /****************************************************************************
32  *  Author: Thomas E. Dickey 2002-on                                        *
33  ****************************************************************************/
34 
35 /*
36 **	lib_get_wch.c
37 **
38 **	The routine get_wch().
39 **
40 */
41 
42 #include <curses.priv.h>
43 #include <ctype.h>
44 
45 MODULE_ID("$Id: lib_get_wch.c,v 1.1 2010/09/06 17:26:17 nicm Exp $")
46 
47 #if HAVE_MBTOWC && HAVE_MBLEN
48 #define reset_mbytes(state) mblen(NULL, 0), mbtowc(NULL, NULL, 0)
49 #define count_mbytes(buffer,length,state) mblen(buffer,length)
50 #define check_mbytes(wch,buffer,length,state) \
51 	(int) mbtowc(&wch, buffer, length)
52 #define state_unused
53 #elif HAVE_MBRTOWC && HAVE_MBRLEN
54 #define reset_mbytes(state) init_mb(state)
55 #define count_mbytes(buffer,length,state) mbrlen(buffer,length,&state)
56 #define check_mbytes(wch,buffer,length,state) \
57 	(int) mbrtowc(&wch, buffer, length, &state)
58 #else
59 make an error
60 #endif
61 
62 NCURSES_EXPORT(int)
63 wget_wch(WINDOW *win, wint_t *result)
64 {
65     SCREEN *sp;
66     int code;
67     char buffer[(MB_LEN_MAX * 9) + 1];	/* allow some redundant shifts */
68     int status;
69     size_t count = 0;
70     unsigned long value;
71     wchar_t wch;
72 #ifndef state_unused
73     mbstate_t state;
74 #endif
75 
76     T((T_CALLED("wget_wch(%p)"), win));
77 
78     /*
79      * We can get a stream of single-byte characters and KEY_xxx codes from
80      * _nc_wgetch(), while we want to return a wide character or KEY_xxx code.
81      */
82     _nc_lock_global(curses);
83     sp = _nc_screen_of(win);
84     if (sp != 0) {
85 	for (;;) {
86 	    T(("reading %d of %d", (int) count + 1, (int) sizeof(buffer)));
87 	    code = _nc_wgetch(win, &value, TRUE EVENTLIST_2nd((_nc_eventlist
88 							       *) 0));
89 	    if (code == ERR) {
90 		break;
91 	    } else if (code == KEY_CODE_YES) {
92 		/*
93 		 * If we were processing an incomplete multibyte character,
94 		 * return an error since we have a KEY_xxx code which
95 		 * interrupts it.  For some cases, we could improve this by
96 		 * writing a new version of lib_getch.c(!), but it is not clear
97 		 * whether the improvement would be worth the effort.
98 		 */
99 		if (count != 0) {
100 		    _nc_ungetch(sp, (int) value);
101 		    code = ERR;
102 		}
103 		break;
104 	    } else if (count + 1 >= sizeof(buffer)) {
105 		_nc_ungetch(sp, (int) value);
106 		code = ERR;
107 		break;
108 	    } else {
109 		buffer[count++] = (char) UChar(value);
110 		reset_mbytes(state);
111 		status = count_mbytes(buffer, count, state);
112 		if (status >= 0) {
113 		    reset_mbytes(state);
114 		    if (check_mbytes(wch, buffer, count, state) != status) {
115 			code = ERR;	/* the two calls should match */
116 			_nc_ungetch(sp, (int) value);
117 		    }
118 		    value = wch;
119 		    break;
120 		}
121 	    }
122 	}
123     } else {
124 	code = ERR;
125     }
126     *result = value;
127     _nc_unlock_global(curses);
128     T(("result %#lo", value));
129     returnCode(code);
130 }
131