pad(3ncurses)

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

   The XSI Curses standard, Issue 4 describes these functions.

SEE ALSO

   ncurses(3NCURSES), refresh(3NCURSES), touch(3NCURSES), addch(3NCURSES).

                                                             pad(3NCURSES)

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