manager: Show tracked devices as a property

src/calng/CalibrationManager.py

@@ -412,6 +412,12 @@ class CalibrationManager(DeviceClientBase, Device):
         self.state = State.CHANGING
         background(self._instantiate_pipeline())
 
+    managedDevices = VectorString(
+        displayedName='Managed devices',
+        description='List of currently managed devices.',
+        defaultValue=[],
+        accessMode=AccessMode.READONLY)
+
     @Slot(
         displayedName='Discover managed devices',
         description='',
@@ -428,7 +434,7 @@ class CalibrationManager(DeviceClientBase, Device):
     async def applyManagedValues(self):
         background(self._apply_managed_values())
 
-    managed = Node(
+    managedKeys = Node(
         ManagedKeysNode,
         displayedName='Managed keys',
         description='Properties and slots managed on devices in the pipeline.')
@@ -464,6 +470,9 @@ class CalibrationManager(DeviceClientBase, Device):
         # in the same domain and having the specified class ID.
         self._correction_device_ids = set()
 
+        # Task object to update managed devices list.
+        self._managed_devices_updater = None
+
     async def onInitialization(self):
         self.state = State.INIT
 
@@ -482,6 +491,7 @@ class CalibrationManager(DeviceClientBase, Device):
 
         if info['type'] == 'device':
             self._check_new_device(instance_id, info['classId'])
+            self._update_managed_devices()
 
     @slot
     def slotInstanceGone(self, instance_id, info):
@@ -493,6 +503,7 @@ class CalibrationManager(DeviceClientBase, Device):
             self._daq_device_ids.discard(instance_id)
             self._domain_device_ids.discard(instance_id)
             self._correction_device_ids.discard(instance_id)
+            self._update_managed_devices()
 
     async def _async_init(self):
         # Populate the device ID sets with what's out there right now.
@@ -523,7 +534,10 @@ class CalibrationManager(DeviceClientBase, Device):
 
         elif device_id.startswith(self._device_id_root):
             # This device lives under the same device ID root as this
-            # manager instance.
+            # manager instance, but don't add yourself!
+            if device_id == self.deviceId:
+                return
+
             self._domain_device_ids.add(device_id)
 
             if class_id == self._correction_class_id:
@@ -551,6 +565,8 @@ class CalibrationManager(DeviceClientBase, Device):
         for device_id in devices:
             self._check_new_device(device_id, devices[device_id, 'classId'])
 
+        self._update_managed_devices(True)
+
     async def _discover_managed_devices(self):
         self._daq_device_ids.clear()
         self._domain_device_ids.clear()
@@ -560,6 +576,25 @@ class CalibrationManager(DeviceClientBase, Device):
 
         self.state = State.ACTIVE
 
+    async def _delayed_managed_devices_update(self):
+        await sleep(1.0)  # Throttle updates to at most once a second.
+        self.managedDevices = sorted(
+            self._domain_device_ids | self._daq_device_ids)
+
+        self._managed_devices_updater = None  # Clear task again.
+
+    def _update_managed_devices(self, forced=False):
+        if self._managed_devices_updater is not None:
+            # Update already in progress, ignore.
+            return
+
+        all_managed_devices = self._domain_device_ids | self._daq_device_ids
+        if forced or len(all_managed_devices) != len(self.managedDevices):
+            # Trigger an update either if forced or the number of
+            # devices changed.
+            self._managed_devices_updater = background(
+                self._delayed_managed_devices_update())
+
     async def _get_shared_keys(self, device_ids, keys):
         """Find the most common property values on devices."""
 
@@ -682,9 +717,9 @@ class CalibrationManager(DeviceClientBase, Device):
         # The value are then obtained from the Node object again since
         # enums are converted to their values by toSchemaAndAttrs, which
         # in turn is not valid for property definition.
-        _, attrs = Descriptor.toSchemaAndAttrs(self.__class__.managed,
+        _, attrs = Descriptor.toSchemaAndAttrs(self.__class__.managedKeys,
                                                None, None)
-        managed_node_attrs = {key: getattr(self.__class__.managed, key)
+        managed_node_attrs = {key: getattr(self.__class__.managedKeys, key)
                               for key in attrs.keys()}
 
         # Build a proxy from the managed schema, and create a new node
@@ -712,7 +747,7 @@ class CalibrationManager(DeviceClientBase, Device):
                                                    remote_key=remote_key):
                         background(self._call_on_corrections(remote_key))
 
-                    _managed_slot_called.__name__ = f'managed.{local_key}'
+                    _managed_slot_called.__name__ = f'managedKeys.{local_key}'
                     descr.__call__(_managed_slot_called)
 
                     # Managed slots can only be called in the ACTIVE
@@ -761,7 +796,7 @@ class CalibrationManager(DeviceClientBase, Device):
         _sanitize_node(managed_node, managed_hash)
 
         # Inject the newly prepared node for managed keys.
-        self.__class__.managed = managed_node
+        self.__class__.managedKeys = managed_node
         await self.publishInjectedParameters()
         self._managed_keys = managed_keys