Add return typehints to magic methods

src/openflexure_microscope_server/things/camera/__init__.py

@@ -69,7 +69,7 @@ class CameraMemoryBuffer:
 
     _storage: dict[int, tuple[Any, Optional[dict]]]
 
-    def __init__(self):
+    def __init__(self) -> None:
         """Create the buffer instance."""
         # This dictionary is the main store for data. Dictionaries are ordered since
         # Python 3.6, so the order in the dictionary is the capture order
@@ -170,7 +170,7 @@ class BaseCamera(lt.Thing):
     lores_mjpeg_stream = lt.outputs.MJPEGStreamDescriptor()
     _memory_buffer = CameraMemoryBuffer()
 
-    def __init__(self):
+    def __init__(self) -> None:
         """Initialise the base camera, this creates the background detectors.
 
         This must be run by all child camera classes.

src/openflexure_microscope_server/things/camera/opencv.py

@@ -25,7 +25,7 @@ from . import BaseCamera
 class OpenCVCamera(BaseCamera):
     """A Thing that provides and interface to an OpenCV Camera."""
 
-    def __init__(self, camera_index: int = 0):
+    def __init__(self, camera_index: int = 0) -> None:
         """Iniatilise the thing storing the index of the camera to use.
 
         :param camera_index: The index of the camera to use for the microscope.
@@ -35,7 +35,7 @@ class OpenCVCamera(BaseCamera):
         self._capture_thread: Optional[Thread] = None
         self._capture_enabled = False
 
-    def __enter__(self):
+    def __enter__(self) -> None:
         """Start the capture thread when the Thing context manager is opened."""
         self.cap = cv2.VideoCapture(self.camera_index)
         self._capture_enabled = True
@@ -48,7 +48,7 @@ class OpenCVCamera(BaseCamera):
         _exc_type: type[BaseException],
         _exc_value: Optional[BaseException],
         _traceback: Optional[TracebackType],
-    ):
+    ) -> None:
         """Release the camera when the Thing context manager is closed.
 
         Before releasing the camera the capture thread is closed.

src/openflexure_microscope_server/things/camera/picamera.py

@@ -53,7 +53,9 @@ class MissingCalibrationError(RuntimeError):
 class PicameraStreamOutput(Output):
     """An Output class that sends frames to a stream."""
 
-    def __init__(self, stream: lt.outputs.MJPEGStream, portal: lt.deps.BlockingPortal):
+    def __init__(
+        self, stream: lt.outputs.MJPEGStream, portal: lt.deps.BlockingPortal
+    ) -> None:
         """Create an output that puts frames in an MJPEGStream.
 
         We need to pass the stream object, and also the blocking portal, because
@@ -126,7 +128,7 @@ class StreamingPiCamera2(BaseCamera):
     generalisation.
     """
 
-    def __init__(self, camera_num: int = 0):
+    def __init__(self, camera_num: int = 0) -> None:
         """Initialise the camera with the given camera number.
 
         This makes no connection to the camera (except to get the default tuning file).
@@ -384,7 +386,7 @@ class StreamingPiCamera2(BaseCamera):
             )
         self._picamera_lock = RLock()
 
-    def __enter__(self):
+    def __enter__(self) -> None:
         """Start streaming when the Thing context manager is opened.
 
         This opens the picamera connection, initialises the camera, sets the
@@ -430,7 +432,7 @@ class StreamingPiCamera2(BaseCamera):
         _exc_type: type[BaseException],
         _exc_value: Optional[BaseException],
         _traceback: Optional[TracebackType],
-    ):
+    ) -> None:
         """Close the picamera connection when the Thing context manager is closed."""
         self.stop_streaming()
         with self._streaming_picamera() as cam:

src/openflexure_microscope_server/things/camera/simulation.py

@@ -54,7 +54,7 @@ class SimulatedCamera(BaseCamera):
         glyph_shape: tuple[int, int, int] = (91, 91, 3),
         canvas_shape: tuple[int, int, int] = (3000, 4000, 3),
         frame_interval: float = 0.1,
-    ):
+    ) -> None:
         """Initialise the simulated with settings for how images are generated.
 
         :param shape: The shape (size) of the generated image.
@@ -208,7 +208,7 @@ class SimulatedCamera(BaseCamera):
             pos = {"x": 0, "y": 0, "z": 0}
         return self.generate_image((pos["y"], pos["x"], pos["z"]))
 
-    def __enter__(self):
+    def __enter__(self) -> None:
         """Start the capture thread when the Thing context manager is opened."""
         self.start_streaming()
         return self
@@ -218,7 +218,7 @@ class SimulatedCamera(BaseCamera):
         _exc_type: type[BaseException],
         _exc_value: Optional[BaseException],
         _traceback: Optional[TracebackType],
-    ):
+    ) -> None:
         """Close the capture thread when the Thing context manager is closed."""
         if self.stream_active:
             self._capture_enabled = False