overlay, overwrite, copywin - overlay and manipulate
overlapped curses windows
int overlay(const WINDOW *srcwin, WINDOW
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.
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.
Routines that return an integer return ERR upon failure, and OK
(SVr4 only specifies "an integer value other than ERR") upon
int overwrite(const WINDOW *srcwin, WINDOW
int copywin(const WINDOW *srcwin, WINDOW
*dstwin, int sminrow,
int smincol, int dminrow, int
dmincol , int dmaxrow,
int dmaxcol, int overlay);
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.
Note that overlay and overwrite may be macros.
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).