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. Automat‐
ic 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 posi‐
tion (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 rec‐
tangle 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 knowl‐
edge that only a single character is being output is taken into consideration and, for non-control char‐
acters, a considerable performance gain might be seen by using these routines instead of their equiva‐
lents. 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 pre‐
fresh.

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 re‐
               turns an error.

NOTES

       Note that pechochar may be a macro.

PORTABILITY