# curs_window 3x

    curs_window(3x)                                         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

### newwin

           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).

### delwin

           Calling delwin deletes the named window, freeing all memo-
           ry associated with it (it does not actually erase the win-
           dow'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 win-
           dow 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 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) in-
           side its parent window.  The screen-relative parameters of
           the  window are not changed.  This routine is used to dis-
           play 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 whenev-
           er 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 up-
           on  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  implementa-
           tion

           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 in-
                side 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 in-
                side 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, wsyn-
           cup, wsyncdown, wcursyncup, syncok) are flaky, incomplete-
           ly 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),  curs_vari-
           ables(3x)

                                                            curs_window(3x)