touchwin, touchline, untouchwin, wtouchln,
is_linetouched, is_wintouched - curses refresh control
routines
#include <ncurses/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);
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.
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.
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.
All of these routines except wtouchln may be macros.