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 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 rou-tine routine
tine 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 win-dow. window.
dow. 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 win-dow. window.
dow.
PORTABILITY
The XSI Curses standard, Issue 4 describes these functions.
Some historic curses implementations had, as an undocumented feature, the ability to do the equiva-lent equivalent
lent of clearok(..., 1) by saying touchwin(stdscr) or clear(stdscr). This will not work under ncurs-es. ncurses.
es.
NOTES
Note that all routines except wtouchln may be macros.
SEE ALSO
curses(3X), curs_refresh(3X).
curs_touch(3X)
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