AYABInterface/communication/host_messages.py
"""This module contains the messages that are sent to the controller."""
class Message(object):
"""This is the interface for sent messages."""
def __init__(self, file, communication, *args, **kw):
"""Create a new Request object"""
self._file = file
self._communication = communication
assert self.MESSAGE_ID is not None
self.init(*args, **kw)
def is_from_host(self):
"""Whether this message is sent by the host.
:rtype: bool
:return: :obj:`True`
"""
return True
def is_from_controller(self):
"""Whether this message is sent by the controller.
:rtype: bool
:return: :obj:`False`
"""
return False
def init(self):
"""Override this method."""
MESSAGE_ID = None #: the first byte to identify this message
def content_bytes(self):
"""The message content as bytes.
:rtype: bytes
"""
return b''
def as_bytes(self):
"""The message represented as bytes.
:rtype: bytes
"""
return bytes([self.MESSAGE_ID]) + self.content_bytes()
def send(self):
"""Send this message to the controller."""
self._file.write(self.as_bytes())
self._file.write(b'\r\n')
def __repr__(self):
"""This message as string inclding the bytes.
:rtype: str
"""
return "<{} {}>".format(self.__class__.__name__,
self.as_bytes() + b"\r\n")
def _left_end_needle_error_message(needle):
return "Start needle is {0} but 0 <= {0} <= 198 was expected.".format(
repr(needle))
def _right_end_needle_error_message(needle):
return "Stop needle is {0} but 1 <= {0} <= 199 was expected.".format(
repr(needle))
class StartRequest(Message):
"""This is the start of the conversation.
.. seealso:: :ref:`reqstart`
"""
MESSAGE_ID = 0x01 #: the first byte to identify this message
def init(self, left_end_needle, right_end_needle):
"""Initialize the StartRequest with start and stop needle.
:raises TypeError: if the arguments are not integers
:raises ValueError: if the values do not match the
:ref:`specification <m4-01>`
"""
if not isinstance(left_end_needle, int):
raise TypeError(_left_end_needle_error_message(left_end_needle))
if left_end_needle < 0 or left_end_needle > 198:
raise ValueError(_left_end_needle_error_message(left_end_needle))
if not isinstance(right_end_needle, int):
raise TypeError(_right_end_needle_error_message(right_end_needle))
if right_end_needle < 1 or right_end_needle > 199:
raise ValueError(_right_end_needle_error_message(right_end_needle))
self._left_end_needle = left_end_needle
self._right_end_needle = right_end_needle
@property
def left_end_needle(self):
"""The needle to start knitting with.
:rtype: int
:return: value where ``0 <= value <= 198``
"""
return self._left_end_needle
@property
def right_end_needle(self):
"""The needle to start knitting with.
:rtype: int
:return: value where ``1 <= value <= 199``
"""
return self._right_end_needle
def content_bytes(self):
"""Return the start and stop needle.
:rtype: bytes
"""
return bytes([self._left_end_needle, self._right_end_needle])
class LineConfirmation(Message):
"""This message send the data to configure a line.
.. seealso:: :ref:`cnfline`
"""
MESSAGE_ID = 0x42 #: the first byte to identify this message
def init(self, line_number):
"""Initialize the StartRequest with the line number."""
self._line_number = line_number
def content_bytes(self):
"""Return the start and stop needle."""
get_message = \
self._communication.needle_positions.get_line_configuration_message
return get_message(self._line_number)
class InformationRequest(Message):
"""Start the initial handshake.
.. seealso:: :ref:`reqinfo`,
:class:`InformationConfirmation
<AYABInterface.communication.hardware_messages.InformationConfirmation>`
"""
MESSAGE_ID = 0x03 #: the first byte to identify this message
class TestRequest(Message):
"""Start the test mode of the controller.
.. seealso:: :ref:`reqtest`,
:class:`InformationConfirmation
<AYABInterface.communication.hardware_messages.TestConfirmation>`
"""
MESSAGE_ID = 0x04 #: the first byte to identify this message
__all__ = ["Message", "StartRequest", "LineConfirmation",
"InformationRequest", "TestRequest"]