linuxjsdev.py 文件源码

def open(self):
        if self._f:
            raise Exception("{} at {} is already "
                            "opened".format(self.name, self._f_name))

        self._f = open("/dev/input/js{}".format(self.num), "rb")
        fcntl.fcntl(self._f.fileno(), fcntl.F_SETFL, os.O_NONBLOCK)

        # Get number of axis and button
        val = ctypes.c_int()
        if fcntl.ioctl(self._f.fileno(), JSIOCGAXES, val) != 0:
            self._f.close()
            self._f = None
            raise Exception("Failed to read number of axes")

        self.axes = list(0 for i in range(val.value))
        if fcntl.ioctl(self._f.fileno(), JSIOCGBUTTONS, val) != 0:
            self._f.close()
            self._f = None
            raise Exception("Failed to read number of axes")

        self.buttons = list(0 for i in range(val.value))
        self.__initvalues()