Ubuntu Manpage: newpad, subpad, prefresh, pnoutrefresh, pechochar, pecho_wchar

Provided by: ncurses-doc_6.0+20160213-1ubuntu1_all

NAME

       newpad, subpad, prefresh, pnoutrefresh, pechochar, pecho_wchar - create and display curses
       pads

SYNOPSIS

       #include <curses.h>

       WINDOW *newpad(int nlines, int ncols);
       WINDOW *subpad(WINDOW *orig, int nlines, int ncols,
             int begin_y, int begin_x);
       int prefresh(WINDOW *pad, int pminrow, int pmincol,
             int sminrow, int smincol, int smaxrow, int smaxcol);
       int pnoutrefresh(WINDOW *pad, int pminrow, int pmincol,
             int sminrow, int smincol, int smaxrow, int smaxcol);
       int pechochar(WINDOW *pad, chtype ch);
       int pecho_wchar(WINDOW *pad, const cchar_t *wch);

DESCRIPTION

newpad
The newpad routine creates and returns a pointer to a new pad data structure with the
given number of lines, nlines, and columns, ncols. A pad is like a window, except that it
is not restricted by the screen size, and is not necessarily associated with a particular
part of the screen. Pads can be used when a large window is needed, and only a part of
the window will be on the screen at one time. Automatic refreshes of pads (e.g., from
scrolling or echoing of input) do not occur. It is not legal to call wrefresh with a pad
as an argument; the routines prefresh or pnoutrefresh should be called instead. Note that
these routines require additional parameters to specify the part of the pad to be
displayed and the location on the screen to be used for the display.

subpad
The subpad routine creates and returns a pointer to a subwindow within a pad with the
given number of lines, nlines, and columns, ncols. Unlike subwin, which uses screen
coordinates, the window is at position (begin_x, begin_y) on the pad. The window is made
in the middle of the window orig, so that changes made to one window affect both windows.
During the use of this routine, it will often be necessary to call touchwin or touchline
on orig before calling prefresh.

prefresh, pnoutrefresh
The prefresh and pnoutrefresh routines are analogous to wrefresh and wnoutrefresh except
that they relate to pads instead of windows. The additional parameters are needed to
indicate what part of the pad and screen are involved. The pminrow and pmincol parameters
specify the upper left-hand corner of the rectangle to be displayed in the pad. The
sminrow, smincol, smaxrow, and smaxcol parameters specify the edges of the rectangle to be
displayed on the screen. The lower right-hand corner of the rectangle to be displayed in
the pad is calculated from the screen coordinates, since the rectangles must be the same
size. Both rectangles must be entirely contained within their respective structures.
Negative values of pminrow, pmincol, sminrow, or smincol are treated as if they were zero.

pechochar
The pechochar routine is functionally equivalent to a call to addch followed by a call to
refresh, a call to waddch followed by a call to wrefresh, or a call to waddch followed by
a call to prefresh. The knowledge that only a single character is being output is taken
into consideration and, for non-control characters, a considerable performance gain might
be seen by using these routines instead of their equivalents. In the case of pechochar,
the last location of the pad on the screen is reused for the arguments to prefresh.

pecho_wchar
The pecho_wchar function is the analogous wide-character form of pechochar. It outputs
one character to a pad and immediately refreshes the pad. It does this by a call to
wadd_wch followed by a call to prefresh.

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.

       Routines that return pointers return NULL on error, and set errno to ENOMEM.

       X/Open does not define any error conditions.  In this implementation

          prefresh and pnoutrefresh
               return  an  error  if the window pointer is null, or if the window is not really a
               pad or if the area to refresh extends off-screen or if the minimum coordinates are
               greater than the maximum.

          pechochar
               returns  an  error  if  the window is not really a pad, and the associated call to
               wechochar returns an error.

          pecho_wchar
               returns an error if the window is not really a pad, and  the  associated  call  to
               wecho_wchar returns an error.

NOTES

       Note that pechochar may be a macro.

PORTABILITY