from __future__ import annotations
from typing import TYPE_CHECKING
if TYPE_CHECKING:
from .packet import Packet
from .sub9_driver import SimulatedUSBtoCANStream, USBtoCANDriver
[docs]class SimulatedCANDeviceHandle:
"""
Simulates a CAN device, with functions to be overridden to handle data requests
and sends from motherboard.
Child classes can inherit from this class to implement a simulated CAN device.
Attributes:
inbound_packets (type[Packet]): The types of packets listened to by this device.
Packets of this type will be routed to the :meth:`~.on_data` method of
the device handle.
"""
def __init__(
self,
sim_board: SimulatedUSBtoCANStream,
inbound_packets: list[type[Packet]],
):
self._sim_board = sim_board
self.inbound_packets = inbound_packets
[docs] def send_data(self, data: bytes):
"""
Sends data over the serial connection.
"""
self._sim_board.send_to_bus(data)
[docs] def on_data(self, packet: Packet):
"""
Called when an relevant incoming packet is received over the serial
connection. Relevant packets are those listed in :attr:`~.inbound_packets`.
Partial data (ie, incomplete packets) are not sent through this event.
Args:
packet (Packet): The incoming packet.
"""
del packet
[docs]class CANDeviceHandle:
"""
Base class to allow developers to write handles for communication with a
particular CAN device. The two methods of the handle allow the handle to listen
to incoming data, as well as send data.
"""
def __init__(self, driver: USBtoCANDriver):
"""
Args:
driver (USBtoCANBoard): Driver that is used to communicate with the board.
device_id (int): The CAN ID of the device this class will handle. Not currently used.
"""
self._driver = driver
[docs] def on_data(self, data: Packet):
"""
Called when a return packet is sent over the serial connection. In the
USB to CAN protocol, it is assumed that packets will be returned to the
motherboard in the order they are sent out. Therefore, the type of packet
sent through this event is not guaranteed, and is only determined by the
message and subclass ID sent by the individual board.
Partial data (ie, incomplete packets) are not sent through this event.
Args:
packet (Packet): The incoming packet.
"""
del data
[docs] def send_data(self, data: Packet):
"""
Sends a packet over the serial connection.
Args:
data (Packet): The packet to send.
"""
return self._driver.send_data(self, data)