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

curs_touch(3X)                                                curs_touch(3X)

NAME         top

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

SYNOPSIS         top

       #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         top

       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         top

       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         top

       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         top

       Note that all routines except wtouchln may be macros.

SEE ALSO         top

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

COLOPHON         top

       This page is part of the ncurses (new curses) project.  Information
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                                                              curs_touch(3X)