Re: in_wch and add_wch

[Thomas Dickey]

On Sat, 2 Sep 2006, Sadrul H Chowdhury wrote:

> Hi.
>
> I am trying to in_wch a wide-character (cchar_t), change the attribute and
> add_wch that to the screen again in the same position. But I am not sure
> what I am doing wrong, because it's not behaving properly.

at the moment, I don't see either.  I built it with a debugging version of 
ncurses, so I could trace it.  I see this chunk:

called {win_wch(stdscr,0xbf97a69c)
return }0
called {wmove(stdscr,1,1)
return }0
called {wadd_wch(stdscr, {{ 0344, 0270, 0212 } | {A_CHARTEXT|A_NORMAL}})
+ called {waddch(stdscr, {0345})
render_char bkg {{ ' ' = 040 }} (0), attrs {A_NORMAL} (0) -> ch {{ 0303, 0245 
}} (0)
+ return }0
+ called {waddch(stdscr, {0271})
render_char bkg {{ ' ' = 040 }} (0), attrs {A_NORMAL} (0) -> ch {{ 0302, 0271 
}} (0)
+ return }0
+ called {waddch(stdscr, {0213})
render_char bkg {{ ' ' = 040 }} (0), attrs {A_NORMAL} (0) -> ch {{ 0302, 0213 
}} (0)
multicolumn 1:2 (1,1)
multicolumn 2:2 (1,2)
cell (1, 1..2) = {{ 0345, 0271, 0213 }}
+ return }0
return }0

and checking the original value written to the 0,0 position, it matches 
the parameter given to wadd_wch().  The trace of the corresponding 
waddch's does not look right - perhaps you've found a bug (will check).

> I have included a sample program which printw()s some multi-column
> characters (the meaning of which I don't know, btw), in_wch one of them, and
> add_wch that without changing anything in a different screen position. The
> output of printw is correct, but the output of add_wch is different
> (incorrect). The code is below:
>
> /*** START ***/
> #define _XOPEN_SOURCE_EXTENDED
> #include <ncursesw/ncurses.h>
> #include <locale.h>
>
> int main()
> {
>   cchar_t ch;
>
>   setlocale(LC_ALL, "");
>   initscr();
>
>   mvprintw(0, 0, "%s", "\u4e0a\u6d77\u6700\u4f4e\u6708\u5de5");
>
>   if (mvin_wch(0, 0, &ch) == OK)
>       mvadd_wch(1, 1, &ch);
>
>   getch();
>   endwin();
>   return 0;
> }
> /*** END ***/
>
> I also tried the wchgat family of functions, without much success. Anyone
> can please tell me what I am doing wrong?
>
> Thanks,
> Sadrul

--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net