curs_overlay 3x 2023-09-30 ncurses 6.4 Library calls

curs_overlay(3x)                 Library calls                curs_overlay(3x)

NAME

       overlay,  overwrite,  copywin  -  overlay curses windows and manipulate
       them

SYNOPSIS

       #include <curses.h>

       int overlay(const WINDOW *srcwin, WINDOW *dstwin);
       int overwrite(const WINDOW *srcwin, WINDOW *dstwin);
       int copywin(const WINDOW *srcwin, WINDOW *dstwin, int sminrow,
             int smincol, int dminrow, int dmincol, int dmaxrow,
             int dmaxcol, int overlay);

DESCRIPTION

overlay, overwrite

       The overlay and overwrite routines overlay srcwin  on  top  of  dstwin.
       scrwin and dstwin are not required to be the same size; only text where
       the two windows overlap is copied.  The difference is that  overlay  is
       non-destructive   (blanks   are   not   copied)  whereas  overwrite  is
       destructive.

copywin

       The copywin routine provides a finer granularity of  control  over  the
       overlay  and  overwrite  routines.   As  in  the  prefresh  routine,  a
       rectangle is specified in the destination  window,  (dminrow,  dmincol)
       and  (dmaxrow,  dmaxcol),  and the upper-left-corner coordinates of the
       source window, (sminrow, smincol).  If the argument  overlay  is  true,
       then copying is non-destructive, as in overlay.

RETURN VALUE

       Routines  that  return an integer return ERR upon failure, and OK (SVr4
       only specifies "an integer  value  other  than  ERR")  upon  successful
       completion.

       X/Open  defines  no error conditions.  In this implementation, copywin,
       overlay and overwrite return an error if either of the window  pointers
       are null, or if some part of the window would be placed off-screen.

NOTES

       Note that overlay and overwrite may be macros.

PORTABILITY

       The  XSI Curses standard, Issue 4 describes these functions (adding the
       const qualifiers).  It further specifies their behavior in the presence
       of  characters  with  multibyte  renditions  (not yet supported in this
       implementation).