NAME

       touchwin, touchline, untouchwin, wtouchln, is_linetouched, is_wintouched - curses refresh
       control routines

SYNOPSIS

       #include <curses.h>
       int touchwin(WINDOW *win);
       int touchline(WINDOW *win, int start, int count);
       int untouchwin(WINDOW *win);
       int wtouchln(WINDOW *win, int y, int n, int changed);
       bool is_linetouched(WINDOW *win, int line);
       bool is_wintouched(WINDOW *win);

DESCRIPTION

       The touchwin and touchline routines throw away all optimization  information  about  which
       parts of the window have been touched, by pretending that the entire window has been drawn
       on.  This is sometimes necessary when using overlapping windows, since  a  change  to  one
       window  affects  the other window, but the records of which lines have been changed in the
       other window do not reflect the change.  The routine touchline only  pretends  that  count
       lines have been changed, beginning with line start.

       The  untouchwin  routine marks all lines in the window as unchanged since the last call to
       wrefresh.

       The wtouchln routine makes n lines in the window, starting at line y, look as if they have
       (changed=1) or have not (changed=0) been changed since the last call to wrefresh.

       The is_linetouched and is_wintouched routines return TRUE if the specified line/window was
       modified since the last call to wrefresh;  otherwise  they  return  FALSE.   In  addition,
       is_linetouched returns ERR if line is not valid for the given window.

RETURN VALUE

       All  routines return the integer ERR upon failure and an integer value other than ERR upon
       successful completion, unless otherwise noted in the preceding routine descriptions.

       X/Open does not define any error conditions.  In this implementation

              is_linetouched
                   returns an error if the window pointer is null,  or  if  the  line  number  is
                   outside  the window.  Note that ERR is distinct from TRUE and FALSE, which are
                   the normal return values of this function.

              wtouchln
                   returns an error if the window pointer is null,  or  if  the  line  number  is
                   outside the window.

PORTABILITY

       The XSI Curses standard, Issue 4 describes these functions.

       Some  historic  curses  implementations had, as an undocumented feature, the ability to do
       the equivalent of clearok(..., 1) by saying touchwin(stdscr) or clear(stdscr).  This  will
       not work under ncurses.

NOTES

       Note that all routines except wtouchln may be macros.

SEE ALSO

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

                                                                                  touch(3NCURSES)