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 win‐
       dow  have been touched, by pretending that the entire window has been drawn on.  This is sometimes neces‐
       sary 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 com‐
       pletion, 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)