curs_bkgrnd 3x 2023-09-16 ncurses 6.4 Library calls

curs_bkgrnd(3x)                  Library calls                 curs_bkgrnd(3x)


       bkgrnd,   wbkgrnd,   bkgrndset,  wbkgrndset,  getbkgrnd,  wgetbkgrnd  -
       manipulate background of a curses window of wide characters


       #include <curses.h>

       int bkgrnd(const cchar_t *wch);
       int wbkgrnd(WINDOW *win, const cchar_t *wch);

       void bkgrndset(const cchar_t *wch );
       void wbkgrndset(WINDOW *win, const cchar_t *wch);

       int getbkgrnd(cchar_t *wch);
       int wgetbkgrnd(WINDOW *win, cchar_t *wch);



       The bkgrndset and wbkgrndset routines manipulate the background of  the
       named  window.   The  window  background is a cchar_t consisting of any
       combination of attributes (i.e., rendition) and a complex character.

       o   The attribute part of the background is combined (OR'ed)  with  all
           non-blank characters that are written into the window with waddch.

       o   Both  the  character  and  attribute  parts  of  the background are
           combined with the blank characters.

       The background becomes a property of the character and moves  with  the
       character   through  any  scrolling  and  insert/delete  line/character

       To the extent possible on a particular terminal, the attribute part  of
       the  background  is displayed as the graphic rendition of the character
       put on the screen.


       The bkgrnd and wbkgrnd functions set the  background  property  of  the
       current  or  specified  window  and  then  apply  this setting to every
       character position in that window:

       o   The rendition of every character on the screen is  changed  to  the
           new background rendition.

       o   Wherever  the former background character appears, it is changed to
           the new background character.


       The getbkgrnd function returns the given  window's  current  background
       character/attribute  pair  via  the  wch  pointer.  If the given window
       pointer is null,  the  character  is  not  updated  (but  no  error  is


       Note that bkgrnd, bkgrndset, and getbkgrnd may be macros.

       X/Open Curses does not provide details on how the rendition is changed.
       This implementation follows the approach used in SVr4 curses, which  is
       explained in the manual page for wbkgd.


       The bkgrndset and wbkgrndset routines do not return a value.

       Upon  successful completion, the other functions return OK.  Otherwise,
       they return ERR:

       o   A null window pointer is treated as an error.

       o   A null character pointer is treated as an error.


       These functions are described in  the  XSI  Curses  standard,  Issue  4
       (X/Open Curses).


       curses(3x), curs_bkgd(3x)

ncurses 6.4                       2023-09-16                   curs_bkgrnd(3x)