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

       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 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.

       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.  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.

       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.

       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 whenev-
       er 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 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)