Provided by: ncurses-doc_6.1+20190803-1ubuntu1_all bug

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

   newwin
       Calling newwin creates and returns a pointer to a new window  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).

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

   mvwin
       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.

   subwin
       Calling  subwin  creates  and  returns  a pointer to a new window with the given number of
       lines, nlines, and columns, ncols.  The window is at position (begin_y,  begin_x)  on  the
       screen.   The  subwindow  shares  memory with the window orig, so that changes made to one
       window will affect both windows.  When  using  this  routine,  it  is  necessary  to  call
       touchwin or touchline on orig before calling wrefresh on the subwindow.

   derwin
       Calling derwin is the same as calling subwin, except that begin_y and begin_x are relative
       to the origin of the window 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.

   dupwin
       Calling dupwin creates an exact duplicate of the window win.

   wsyncup
       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  whenever
       there is a change in the window.

   wsyncdown
       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.

   wcursyncup
       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.

       Routines that return pointers return NULL on error.

       X/Open defines no error conditions.  In this implementation

       delwin
            returns  an  error  if  the window pointer is null, or if the window is the parent of
            another window.

       derwin
            returns an error if the parent window pointer is null, or if any of its ordinates  or
            dimensions  is  negative,  or  if the resulting window does not fit inside the parent
            window.

       dupwin
            returns an error if the window pointer is null.

            This implementation also maintains a list of windows, and  checks  that  the  pointer
            passed to delwin is one that it created, returning an error if it was not..

       mvderwin
            returns  an  error if the window pointer is null, or if some part of the window would
            be placed off-screen.

       mvwin
            returns an error if the window pointer is null, or if the window is really a pad,  or
            if some part of the window would be placed off-screen.

       newwin
            will  fail  if either of its beginning ordinates is negative, or if either the number
            of lines or columns is negative.

       syncok
            returns an error if the window pointer is null.

       subwin
            returns an error if the parent window pointer is null, or if any of its ordinates  or
            dimensions  is  negative,  or  if the resulting window does not fit inside the parent
            window.

       The functions which return a window pointer may also fail if there is insufficient  memory
       for  its  data  structures.   Any  of these functions will fail if the screen has not been
       initialized, i.e., with initscr or newterm.

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, wsyncup, wsyncdown, wcursyncup, syncok)
       are flaky, incompletely 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 patterned on the XPG4 curses standard.  The weaker XPG4 spec may result
       in slower updates.

PORTABILITY

       The XSI Curses standard, Issue 4 describes these functions.

SEE ALSO

       ncurses(3NCURSES), refresh(3NCURSES), touch(3NCURSES), curses_variables(3NCURSES)

                                                                                 window(3NCURSES)