curs_touch(3x) — Linux manual page

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 touchline(WINDOW *win, int start, int count);

       int touchwin(WINDOW *win);
       int wtouchln(WINDOW *win, int y, int n, int changed);

       int untouchwin(WINDOW *win);

       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.

               The constant ERR is distinct from TRUE and FALSE, which
               are the normal return values of this function.  Because
               the function returns a bool, returning ERR (which is
               neither TRUE nor FALSE) may not be supported by the
               compiler.

               To provide error-checking and also match the X/Open
               function prototype, the ERR is provided by a macro named
               is_linetouched.  The actual function returns FALSE when
               it detects an error.

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

PORTABILITY         top

       These functions were introduced by SVr4.  The Solaris curses
       header file, for instance, defines both an actual function and
       macro for each.  The macros give the same result as the actual
       functions.  SVr4 curses does not check the window parameter win
       to ensure that it is not NULL; otherwise this implementation
       behaves the same as SVr4.

       The XSI Curses standard, Issue 4 describes these functions, but
       defines no error conditions.

NOTES         top

       All of these 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 about the project can be found at 
       ⟨https://www.gnu.org/software/ncurses/ncurses.html⟩.  If you have
       a bug report for this manual page, send it to
       bug-ncurses-request@gnu.org.  This page was obtained from the
       project's upstream Git mirror of the CVS repository
       ⟨git://ncurses.scripts.mit.edu/ncurses.git⟩ on 2021-04-01.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-03-28.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

                                                          curs_touch(3X)