wip feat(psi_pos): (#118) add base with optional signals

ophyd_devices/interfaces/base_classes/psi_positioner_base.py

@@ -0,0 +1,115 @@
+from abc import ABC
+
+from ophyd.device import Device
+from ophyd.positioner import PositionerBase
+from ophyd.signal import EpicsSignalBase
+
+_OPTIONAL_SIGNAL = object()
+_REQUIRED_SIGNAL = object()
+_SIGNAL_NOT_AVAILABLE = "Signal not available"
+
+
+class PSIPositionerException(Exception): ...
+
+
+class RequiredSignalNotSpecified(PSIPositionerException): ...
+
+
+class OptionalSignalNotSpecified(PSIPositionerException): ...
+
+
+_SIGNAL_NAMES = {
+    "user_readback",
+    "user_setpoint",
+    "user_offset",
+    "user_offset_dir",
+    "offset_freeze_switch",
+    "set_use_switch",
+    "velocity",
+    "acceleration",
+    "motor_egu",
+    "motor_is_moving",
+    "motor_done_move",
+    "high_limit_switch",
+    "low_limit_switch",
+    "high_limit_travel",
+    "low_limit_travel",
+    "direction_of_travel",
+    "motor_stop",
+    "home_forward",
+    "home_reverse",
+    "tolerated_alarm",
+}
+
+
+class PSIPositionerBase(ABC, Device, PositionerBase):
+    """Base class for positioners which are similar to a motor but do not implement
+    all the required signals for an EpicsMotor or have different PV suffices."""
+
+    # position
+    user_readback = _REQUIRED_SIGNAL
+    user_setpoint = _REQUIRED_SIGNAL
+
+    # calibration dial <-> user
+    user_offset = _OPTIONAL_SIGNAL
+    user_offset_dir = _OPTIONAL_SIGNAL
+    offset_freeze_switch = _OPTIONAL_SIGNAL
+    set_use_switch = _OPTIONAL_SIGNAL
+
+    # configuration
+    velocity = _OPTIONAL_SIGNAL
+    acceleration = _OPTIONAL_SIGNAL
+    motor_egu = _OPTIONAL_SIGNAL
+
+    # motor status
+    motor_is_moving = _OPTIONAL_SIGNAL
+    motor_done_move = _OPTIONAL_SIGNAL
+    high_limit_switch = _OPTIONAL_SIGNAL
+    low_limit_switch = _OPTIONAL_SIGNAL
+    high_limit_travel = _OPTIONAL_SIGNAL
+    low_limit_travel = _OPTIONAL_SIGNAL
+    direction_of_travel = _OPTIONAL_SIGNAL
+
+    # commands
+    motor_stop = _OPTIONAL_SIGNAL
+    home_forward = _OPTIONAL_SIGNAL
+    home_reverse = _OPTIONAL_SIGNAL
+
+    # alarm information
+    tolerated_alarm = _OPTIONAL_SIGNAL
+
+    def __init__(
+        self,
+        prefix="",
+        *,
+        name,
+        kind=None,
+        read_attrs=None,
+        configuration_attrs=None,
+        parent=None,
+        child_name_separator="_",
+        connection_timeout=...,
+        **kwargs,
+    ):
+        super().__init__(
+            prefix,
+            name=name,
+            kind=kind,
+            read_attrs=read_attrs,
+            configuration_attrs=configuration_attrs,
+            parent=parent,
+            child_name_separator=child_name_separator,
+            connection_timeout=connection_timeout,
+            **kwargs,
+        )
+
+        not_implemented = {
+            signal for signal in _SIGNAL_NAMES if getattr(self, signal) is _REQUIRED_SIGNAL
+        }
+        if not_implemented != set():
+            raise RequiredSignalNotSpecified(
+                f"Signal(s) {not_implemented} must be defined in a subclass"
+            )
+        # Make the default alias for the user_readback the name of the motor itself
+        # for compatibility with EpicsMotor
+        self.user_readback.name = self.name

tests/test_psi_positioner_base.py

@@ -0,0 +1,27 @@
+from unittest.mock import MagicMock
+
+import pytest
+from ophyd.device import Component as Cpt
+from ophyd.signal import EpicsSignal
+from ophyd.sim import FakeEpicsSignal, FakeEpicsSignalRO
+
+from ophyd_devices.interfaces.base_classes.psi_positioner_base import (
+    PSIPositionerBase,
+    RequiredSignalNotSpecified,
+)
+
+
+def test_cannot_isntantiate_without_required_signals():
+    class PSITestPositionerWOSignal(PSIPositionerBase): ...
+
+    class PSITestPositionerWithSignal(PSIPositionerBase):
+        user_setpoint: EpicsSignal = Cpt(FakeEpicsSignal, ".VAL", limits=True, auto_monitor=True)
+        user_readback = Cpt(FakeEpicsSignalRO, ".RBV", kind="hinted", auto_monitor=True)
+
+    with pytest.raises(RequiredSignalNotSpecified) as e:
+        PSITestPositionerWOSignal("", name="")
+        assert e.match("user_setpoint")
+        assert e.match("user_readback")
+
+    dev = PSITestPositionerWithSignal("", name="")
+    assert dev.user_setpoint.get() == 0