# curs_window 3x

## NAME

           newwin,  delwin,  mvwin, subwin, derwin, mvderwin, dupwin,
           wsyncup, syncok, wcursyncup,  wsyncdown  -  create  curses
           windows

## SYNOPSIS

           #include <curses.h>

           WINDOW *newwin(int nlines, int ncols, int begin_y,
                 int begin_x);
           int delwin(WINDOW *win);
           int mvwin(WINDOW *win, int y, int x);
           WINDOW *subwin(WINDOW *orig, int nlines, int ncols,
                 int begin_y, int begin_x);
           WINDOW *derwin(WINDOW *orig, int nlines, int ncols,
                 int begin_y, int begin_x);
           int mvderwin(WINDOW *win, int par_y, int par_x);
           WINDOW *dupwin(WINDOW *win);
           void wsyncup(WINDOW *win);
           int syncok(WINDOW *win, bool bf);
           void wcursyncup(WINDOW *win);
           void wsyncdown(WINDOW *win);

## DESCRIPTION

           Calling newwin creates and returns a pointer to a new win-
           dow with the given number of lines and columns.  The upper
           left-hand  corner of the window is at line begin_y, column
           begin_x.  If either nlines or ncols is zero, they  default
           to  LINES - begin_y and COLS - begin_x.  A new full-screen
           window is created by calling newwin(0,0,0,0).

           Calling delwin deletes the named window, freeing all  mem-
           ory  associated  with  it  (it does not actually erase the
           window's screen image).  Subwindows must be deleted before
           the main window can be deleted.

           Calling mvwin moves the window so that the upper left-hand
           corner is at position (x, y).  If the move would cause the
           window to be off the screen, it is an error and the window
           is not moved.  Moving subwindows is allowed, but should be
           avoided.

           Calling subwin creates and returns a pointer to a new win-
           dow with the given number of lines, nlines,  and  columns,
           ncols.   The  window  is at position (begin_y, begin_x) on
           the screen.  (This position is relative to the screen, and
           not to the window orig.)  The window is made in the middle
           of the window orig, so that changes  made  to  one  window
           will  affect  both  windows.   The subwindow shares memory
           with the window orig.  When using this routine, it is nec-
           essary  to call touchwin or touchline on orig before call-
           ing wrefresh on the subwindow.

           Calling derwin is the same as calling subwin, except  that
           begin_y and begin_x are relative to the origin of the win-
           dow orig rather than the screen.  There is  no  difference
           between the subwindows and the derived windows.

           Calling  mvderwin  moves  a  derived window (or subwindow)
           inside its parent window.  The screen-relative  parameters
           of  the  window  are not changed.  This routine is used to
           display different parts of the parent window at  the  same
           physical position on the screen.

           Calling  dupwin  creates  an exact duplicate of the window
           win.

           Calling wsyncup touches all locations in ancestors of  win
           that  are changed in win.  If syncok is called with second
           argument TRUE then wsyncup is called  automatically  when-
           ever there is a change in the window.

           The  wsyncdown  routine  touches each location in win that
           has been touched in any of  its  ancestor  windows.   This
           routine  is  called by wrefresh, so it should almost never
           be necessary to call it manually.

           The routine wcursyncup updates the current cursor position
           of  all the ancestors of the window to reflect the current
           cursor position of the window.

## RETURN VALUE

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

           delwin returns the integer ERR upon failure  and  OK  upon
           successful completion.

           Routines that return pointers return NULL on error.

## NOTES

           If  many small changes are made to the window, the wsyncup
           option could degrade performance.

           Note that syncok may be a macro.

## BUGS

           The subwindow functions (subwin, derwin,  mvderwin,  wsyn-
           cup,  wsyncdown,  wcursyncup,  syncok)  are  flaky, incom-
           pletely implemented, and not well tested.

           The System V curses documentation is  very  unclear  about
           what wsyncup and wsyncdown actually do.  It seems to imply
           that they are only supposed to touch exactly  those  lines
           that are affected by ancestor changes.  The language here,
           and the behavior of the  curses  implementation,  is  pat-
           terned  on the XPG4 curses standard.  The weaker XPG4 spec
           may result in slower updates.

## PORTABILITY

           The XSI Curses standard, Issue  4  describes  these  func-
           tions.

## SEE ALSO

           curses(3x), curs_refresh(3x), curs_touch(3x)