curs_touch(3X)							curs_touch(3X)

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	infor‐
       mation 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 speci‐
       fied line/window was modified since the last call to  wrefresh;	other‐
       wise  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 dis‐
		   tinct from TRUE and FALSE, which are the normal return val‐
		   ues 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 touch‐
       win(stdscr) or clear(stdscr).  This will not work under ncurses.

NOTES
       Note that all routines except wtouchln may be macros.

SEE ALSO
       curses(3X), curs_refresh(3X), curs_variables(3X).

								curs_touch(3X)

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