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28 
29 /****************************************************************************
30  *  Author: Thomas E. Dickey 2002-on                                        *
31  ****************************************************************************/
32 
33 /*
34 **	lib_get_wch.c
35 **
36 **	The routine get_wch().
37 **
38 */
39 
40 #include <curses.priv.h>
41 #include <ctype.h>
42 
43 MODULE_ID("$Id: lib_get_wch.c,v 1.22 2010/08/28 21:00:35 tom Exp $")
44 
45 NCURSES_EXPORT(int)
46 wget_wch(WINDOW *win, wint_t *result)
47 {
48     SCREEN *sp;
49     int code;
50     char buffer[(MB_LEN_MAX * 9) + 1];	/* allow some redundant shifts */
51     int status;
52     size_t count = 0;
53     int value = 0;
54     wchar_t wch;
55 #ifndef state_unused
56     mbstate_t state;
57 #endif
58 
59     T((T_CALLED("wget_wch(%p)"), (void *) win));
60 
61     /*
62      * We can get a stream of single-byte characters and KEY_xxx codes from
63      * _nc_wgetch(), while we want to return a wide character or KEY_xxx code.
64      */
65     _nc_lock_global(curses);
66     sp = _nc_screen_of(win);
67     if (sp != 0) {
68 	for (;;) {
69 	    T(("reading %d of %d", (int) count + 1, (int) sizeof(buffer)));
70 	    code = _nc_wgetch(win, &value, TRUE EVENTLIST_2nd((_nc_eventlist
71 							       *) 0));
72 	    if (code == ERR) {
73 		break;
74 	    } else if (code == KEY_CODE_YES) {
75 		/*
76 		 * If we were processing an incomplete multibyte character,
77 		 * return an error since we have a KEY_xxx code which
78 		 * interrupts it.  For some cases, we could improve this by
79 		 * writing a new version of lib_getch.c(!), but it is not clear
80 		 * whether the improvement would be worth the effort.
81 		 */
82 		if (count != 0) {
83 		    safe_ungetch(SP_PARM, value);
84 		    code = ERR;
85 		}
86 		break;
87 	    } else if (count + 1 >= sizeof(buffer)) {
88 		safe_ungetch(SP_PARM, value);
89 		code = ERR;
90 		break;
91 	    } else {
92 		buffer[count++] = (char) UChar(value);
93 		reset_mbytes(state);
94 		status = count_mbytes(buffer, count, state);
95 		if (status >= 0) {
96 		    reset_mbytes(state);
97 		    if (check_mbytes(wch, buffer, count, state) != status) {
98 			code = ERR;	/* the two calls should match */
99 			safe_ungetch(SP_PARM, value);
100 		    }
101 		    value = wch;
102 		    break;
103 		}
104 	    }
105 	}
106     } else {
107 	code = ERR;
108     }
109     *result = (wint_t) value;
110     _nc_unlock_global(curses);
111     T(("result %#o", value));
112     returnCode(code);
113 }
114