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).