detector demo device is now a standard readable. Tango devices can au…

…tomatically infer their signals but the tango device server does not necessarily carry information about subdevices. Individual device servers should not have sub-devices but tango device databases can. This may be the subject of a future pr. Made tango_signal_auto private to discourage use.

src/ophyd_async/tango/__init__.py

@@ -7,6 +7,7 @@
     AttributeProxy,
     CommandProxy,
     TangoSignalBackend,
+    __tango_signal_auto,
     ensure_proper_executor,
     get_dtype_extended,
     get_python_type,
@@ -15,7 +16,6 @@
     infer_python_type,
     infer_signal_character,
     make_backend,
-    tango_signal_auto,
     tango_signal_r,
     tango_signal_rw,
     tango_signal_w,
@@ -37,7 +37,7 @@
     "AttributeProxy",
     "CommandProxy",
     "ensure_proper_executor",
-    "tango_signal_auto",
+    "__tango_signal_auto",
     "tango_signal_r",
     "tango_signal_rw",
     "tango_signal_w",

src/ophyd_async/tango/base_devices/_base_device.py

@@ -14,7 +14,11 @@
     DeviceVector,
     Signal,
 )
-from ophyd_async.tango.signal import TangoSignalBackend, make_backend, tango_signal_auto
+from ophyd_async.tango.signal import (
+    TangoSignalBackend,
+    __tango_signal_auto,
+    make_backend,
+)
 from tango import DeviceProxy as DeviceProxy
 from tango.asyncio import DeviceProxy as AsyncDeviceProxy
 
@@ -193,7 +197,7 @@ async def _fill_proxy_entries(device: TangoDevice):
         if name not in children:
             full_trl = f"{proxy_trl}/{name}"
             try:
-                auto_signal = await tango_signal_auto(
+                auto_signal = await __tango_signal_auto(
                     trl=full_trl, device_proxy=device.proxy
                 )
                 setattr(device, name, auto_signal)

src/ophyd_async/tango/demo/_detector.py

@@ -3,31 +3,27 @@
 from ophyd_async.core import (
     AsyncStatus,
     DeviceVector,
+    StandardReadable,
 )
-from ophyd_async.tango import TangoReadable
 
 from ._counter import TangoCounter
 from ._mover import TangoMover
 
 
-class TangoDetector(TangoReadable):
-    counters: DeviceVector[TangoCounter]
-    mover: TangoMover
-
-    def __init__(self, trl: str, mover_trl: str, counter_trls: list[str], name=""):
-        super().__init__(trl, name=name)
-
-        # If devices are inferred from type hints, they will be created automatically
-        # during init. If they are created automatically, their trl must be set before
-        # they are connected.
-        self.mover.set_trl(mover_trl)
-        for i, c_trl in enumerate(counter_trls):
-            self.counters[i + 1] = TangoCounter(c_trl)
+class TangoDetector(StandardReadable):
+    def __init__(self, mover_trl: str, counter_trls: list[str], name=""):
+        # A detector device may be composed of tango sub-devices
+        self.mover = TangoMover(mover_trl)
+        self.counters = DeviceVector(
+            {i + 1: TangoCounter(c_trl) for i, c_trl in enumerate(counter_trls)}
+        )
 
         # Define the readables for TangoDetector
         # DeviceVectors are incompatible with AsyncReadable. Ignore until fixed.
         self.add_readables([self.counters, self.mover])  # type: ignore
 
+        super().__init__(name=name)
+
     def set(self, value):
         return self.mover.set(value)
 

src/ophyd_async/tango/signal/__init__.py

@@ -1,8 +1,8 @@
 from ._signal import (
+    __tango_signal_auto,
     infer_python_type,
     infer_signal_character,
     make_backend,
-    tango_signal_auto,
     tango_signal_r,
     tango_signal_rw,
     tango_signal_w,
@@ -35,5 +35,5 @@
     "tango_signal_rw",
     "tango_signal_w",
     "tango_signal_x",
-    "tango_signal_auto",
+    "__tango_signal_auto",
 )

src/ophyd_async/tango/signal/_signal.py

@@ -128,7 +128,7 @@ def tango_signal_x(
     return SignalX(backend, timeout=timeout, name=name)
 
 
-async def tango_signal_auto(
+async def __tango_signal_auto(
     datatype: type[T] | None = None,
     *,
     trl: str,

tests/tango/test_base_device.py

@@ -377,7 +377,6 @@ async def test_with_bluesky(tango_test_device):
 async def test_tango_demo(demo_test_context):
     with demo_test_context:
         detector = TangoDetector(
-            trl="",
             name="detector",
             mover_trl="demo/motor/1",
             counter_trls=["demo/counter/1", "demo/counter/2"],

tests/tango/test_tango_signals.py

@@ -14,7 +14,7 @@
 from ophyd_async.core import SignalBackend, SignalR, SignalRW, SignalW, SignalX, T
 from ophyd_async.tango import (
     TangoSignalBackend,
-    tango_signal_auto,
+    __tango_signal_auto,
     tango_signal_r,
     tango_signal_rw,
     tango_signal_w,
@@ -646,7 +646,7 @@ async def test_tango_signal_auto_attrs(
     timeout = 0.2
 
     async def _test_signal(dtype, proxy):
-        signal = await tango_signal_auto(
+        signal = await __tango_signal_auto(
             datatype=dtype,
             trl=source,
             device_proxy=proxy,
@@ -720,7 +720,7 @@ async def test_tango_signal_auto_cmds(
     timeout = 0.2
 
     async def _test_signal(dtype, proxy):
-        signal = await tango_signal_auto(
+        signal = await __tango_signal_auto(
             datatype=dtype,
             trl=source,
             device_proxy=proxy,
@@ -751,7 +751,7 @@ async def _test_signal(dtype, proxy):
 @pytest.mark.parametrize("use_proxy", [True, False])
 async def test_tango_signal_auto_cmds_void(tango_test_device: str, use_proxy: bool):
     proxy = await DeviceProxy(tango_test_device) if use_proxy else None
-    signal = await tango_signal_auto(
+    signal = await __tango_signal_auto(
         datatype=None,
         trl=tango_test_device + "/" + "clear",
         device_proxy=proxy,
@@ -767,7 +767,7 @@ async def test_tango_signal_auto_cmds_void(tango_test_device: str, use_proxy: bo
 async def test_tango_signal_auto_badtrl(tango_test_device: str):
     proxy = await DeviceProxy(tango_test_device)
     with pytest.raises(RuntimeError) as exc_info:
-        await tango_signal_auto(
+        await __tango_signal_auto(
             datatype=None,
             trl=tango_test_device + "/" + "badtrl",
             device_proxy=proxy,