Source code for canlib.kvadblib.framebox

from .. import CanlibException
from .message import Message

[docs]class SignalNotFound(CanlibException): def __init__(self, text): super().__init__(self, text)
[docs]class FrameBox: """Helper class for sending signals This class allows sending signals without worrying about what message they are defined in. It does this by binding a message and all its signals to the same `canlib.Frame` object. Objects are created by giving them a `Dbc` database, and optionally a list of messages (either names or `Message` objects):: db = Dbc(...) framebox = FrameBox(db, messages=('Msg0','Msg1')) Messages can also be added after instantiation with `add_message`:: framebox.add_message('Msg0', 'Msg1') Then setting signal values for any added message is done with:: framebox.signal('Sig0').phys = 7 framebox.signal('Sig1').phys = 20 Once all values are set, they can easily be sent via the channel `channel` with:: for frame in framebox.frames(): channel.write(frame) Any `Framebox` methods that return messages requires the message to have been added to the framebox, either with the ``messages`` constructor argument or with `add_message`. Likewise, any methods that return signals require the signal's message to have been added. """ def __init__(self, db, messages=()): self._db = db self._bsigs = {} self._bmsgs = {} for message in messages: self.add_message(message)
[docs] def add_message(self, message): """Add a message to the framebox The message will be available for all future uses of `FrameBox.message` and `FrameBox.messages`, and all its signals will be available for uses of `FrameBox.signal` and `FrameBox.signals`. The ``message`` argument can either be a message name, or a `canlib.kvadblib.Message` object. """ if not isinstance(message, Message): message = self._db.get_message_by_name(message) self._add_msg(message)
[docs] def signal(self, name): """Retrieves a signal by name Returns a `BoundSignal` that shares its `canlib.Frame` object with its parent message and sibling signals. """ try: return self._bsigs[name] except KeyError: raise SignalNotFound("Framebox has no signal named " + repr(name))
[docs] def signals(self): """Iterator over all signals that this `FrameBox` is aware of""" return iter(self._bsigs.values())
[docs] def message(self, name): """Retrieves a message by name Returns a `BoundMessage` that shares its `canlib.Frame` object with its child signals. """ if name not in self._bmsgs: self._add_msg(self._db.get_message_by_name(name)) return self._bmsgs[name]
[docs] def messages(self): """Iterator over all messages that this `FrameBox` is aware of""" return iter(self._bmsgs.values())
[docs] def frames(self): """Iterate over all frames of the signals/messages from this `FrameBox`""" return (bmsg._frame for bmsg in self._bmsgs.values())
def _add_msg(self, message): assert not in self._bmsgs bmsg = message.bind() self._bmsgs[] = bmsg for bsig in bmsg: self._bsigs[] = bsig