Provide base classes in rosidl_pycommon

rosidl_pycommon/rosidl_pycommon/message_base_metaclasses.py

@@ -0,0 +1,67 @@
+# Copyright 2025 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Base Metaclasses
+from abc import ABCMeta
+from abc import abstractmethod
+from collections.abc import MutableMapping
+from typing import Any
+from typing import ClassVar
+from typing import Generic
+from typing import TypeVar
+
+
+class MessageAbstractMeta(ABCMeta):
+
+    _CREATE_ROS_MESSAGE: ClassVar[Any]
+    _CONVERT_FROM_PY: ClassVar[Any]
+    _CONVERT_TO_PY: ClassVar[Any]
+    _DESTROY_ROS_MESSAGE: ClassVar[Any]
+    _TYPE_SUPPORT: ClassVar[Any]
+
+    @classmethod
+    @abstractmethod
+    def __import_type_support__(cls) -> None: ...
+
+    @classmethod
+    @abstractmethod
+    def __prepare__(metacls, name: str, bases: tuple[type[Any], ...], /, **kwds: Any
+                    ) -> MutableMapping[str, object]: ...
+
+
+RequestT = TypeVar('RequestT')
+ResponseT = TypeVar('ResponseT')
+
+
+class ServiceAbstractMeta(ABCMeta, Generic[RequestT, ResponseT]):
+
+    _TYPE_SUPPORT: ClassVar[Any]
+
+    @classmethod
+    @abstractmethod
+    def __import_type_support__(cls) -> None: ...
+
+
+GoalT = TypeVar('GoalT')
+ResultT = TypeVar('ResultT')
+FeedbackT = TypeVar('FeedbackT')
+
+
+class ActionAbstractMeta(ABCMeta, Generic[GoalT, ResultT, FeedbackT]):
+
+    _TYPE_SUPPORT: ClassVar[Any]
+
+    @classmethod
+    @abstractmethod
+    def __import_type_support__(cls) -> None: ...