NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | BUGS | PORTABILITY | SEE ALSO | COLOPHON

curs_window(3X)                                              curs_window(3X)

NAME         top

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

SYNOPSIS         top

       #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         top

   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         top

       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         top

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

       Note that syncok may be a macro.

BUGS         top

       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         top

       The XSI Curses standard, Issue 4 describes these functions.

SEE ALSO         top

       curses(3X), curs_refresh(3X), curs_touch(3X), curs_variables(3X)

COLOPHON         top

       This page is part of the ncurses (new curses) project.  Information
       about the project can be found at 
       ⟨https://www.gnu.org/software/ncurses/ncurses.html⟩.  If you have a
       bug report for this manual page, send it to
       bug-ncurses-request@gnu.org.  This page was obtained from the
       project's upstream Git mirror of the CVS repository 
       ⟨git://ncurses.scripts.mit.edu/ncurses.git⟩ on 2017-07-05.  If you
       discover any rendering problems in this HTML version of the page, or
       you believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

                                                             curs_window(3X)