ncurses (6.4)
curs_touch(3X) curs_touch(3X)
NAME
touchwin, touchline, untouchwin, wtouchln, is_linetouched, is_wintouched - curses refresh control routines
SYNOPSIS
#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);
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.
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
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
All of these routines except wtouchln may be macros.
SEE ALSO
curses(3X), curs_refresh(3X), curs_variables(3X).
curs_touch(3X)
NAME
touchwin, touchline, untouchwin, wtouchln, is_linetouched, is_wintouched - curses refresh control routines
SYNOPSIS
#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);
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.
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
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
All of these routines except wtouchln may be macros.
SEE ALSO
curses(3X), curs_refresh(3X), curs_variables(3X).
curs_touch(3X)