预定义常量
PHP Manual

Newt form exit reasons

Newt form exit reasons
constant meaning
NEWT_EXIT_HOTKEY hotkey defined by newt_form_add_hot_key() was pressed
NEWT_EXIT_COMPONENT some component has caused form to exit
NEWT_EXIT_FDREADY file descriptor specified in newt_form_watch_fd() is ready to be read or written to
NEWT_EXIT_TIMER time specified in newt_form_set_timer() has elapsed

预定义常量
PHP Manual