Consolidate the BaseCamera, CameraStub, and CameraProtocol, move StreamingPiCamera2 to this repo

src/openflexure_microscope_server/things/camera/__init__.py

@@ -10,6 +10,8 @@ from __future__ import annotations
 import logging
 from typing import Literal, Protocol, runtime_checkable, Optional
 
+from pydantic import RootModel
+
 from labthings_fastapi.thing import Thing
 from labthings_fastapi.decorators import thing_action, thing_property
 from labthings_fastapi.dependencies.metadata import GetThingStates
@@ -24,129 +26,14 @@ from labthings_fastapi.types.numpy import NDArray
 class JPEGBlob(Blob):
     media_type: str = "image/jpeg"
 
+class PNGBlob(Blob):
+    media_type: str = "image/png"
 
-@runtime_checkable
-class CameraProtocol(Protocol):
-    """A Thing representing a camera"""
-
-    def __enter__(self) -> None: ...
-
-    def __exit__(self, _exc_type, _exc_value, _traceback) -> None: ...
-
-    @property
-    def stream_active(self) -> bool:
-        "Whether the MJPEG stream is active"
-        ...
-
-    def snap_image(self) -> NDArray:
-        """Acquire one image from the camera."""
-        ...
-
-    def capture_array(
-        self,
-        stream_name: Literal["main", "lores", "raw", "full"] = "main",
-        wait: Optional[float] = 5,
-    ) -> NDArray: ...
-
-    def capture_jpeg(
-        self,
-        metadata_getter: GetThingStates,
-        resolution: Literal["lores", "main", "full"] = "main",
-        wait: Optional[float] = 5,
-    ) -> JPEGBlob:
-        """Acquire one image from the camera and return as a JPEG blob"""
-        ...
-
-    def grab_jpeg(
-        self,
-        portal: BlockingPortal,
-        stream_name: Literal["main", "lores"] = "main",
-    ) -> JPEGBlob:
-        """Acquire one image from the preview stream and return as an array
-
-        This differs from `capture_jpeg` in that it does not pause the MJPEG
-        preview stream. Instead, we simply return the next frame from that
-        stream (either "main" for the preview stream, or "lores" for the low
-        resolution preview). No metadata is returned.
-        """
-        ...
-
-    def grab_jpeg_size(
-        self,
-        portal: BlockingPortal,
-        stream_name: Literal["main", "lores"] = "main",
-    ) -> int:
-        """Acquire one image from the preview stream and return its size"""
-        ...
-
-    def start_streaming(self, main_resolution, buffer_count) -> None:
-        """Start (or stop and restart) the camera with the given resolution
-        for the main stream, and buffer_count number of images in the buffer"""
-        ...
-
-    def capture_image(self, stream_name, wait):
-        """Capture a PIL image from stream stream_name with timeout wait"""
-        ...
-
+class ArrayModel(RootModel):
+    """A model for an array"""
+    root: NDArray
 
 class BaseCamera(Thing):
-    """A Thing representing a camera
-
-    This is a concrete base class for `Thing`s implementing the `CameraProtocol`.
-    It provides the stream descriptors and actions to grab from the stream.
-    """
-
-    mjpeg_stream = MJPEGStreamDescriptor()
-    lores_mjpeg_stream = MJPEGStreamDescriptor()
-
-    @thing_action
-    def snap_image(self) -> NDArray:
-        """Acquire one image from the camera.
-
-        This action cannot run if the camera is in use by a background thread, for
-        example if a preview stream is running.
-        """
-        return self.capture_array()
-
-    @thing_action
-    def grab_jpeg(
-        self,
-        portal: BlockingPortal,
-        stream_name: Literal["main", "lores"] = "main",
-    ) -> JPEGBlob:
-        """Acquire one image from the preview stream and return as an array
-
-        This differs from `capture_jpeg` in that it does not pause the MJPEG
-        preview stream. Instead, we simply return the next frame from that
-        stream (either "main" for the preview stream, or "lores" for the low
-        resolution preview). No metadata is returned.
-        """
-        logging.info(
-            f"StreamingPiCamera2.grab_jpeg(stream_name={stream_name}) starting"
-        )
-        stream = (
-            self.lores_mjpeg_stream if stream_name == "lores" else self.mjpeg_stream
-        )
-        frame = portal.call(stream.grab_frame)
-        logging.info(
-            f"StreamingPiCamera2.grab_jpeg(stream_name={stream_name}) got frame"
-        )
-        return JPEGBlob.from_bytes(frame)
-
-    @thing_action
-    def grab_jpeg_size(
-        self,
-        portal: BlockingPortal,
-        stream_name: Literal["main", "lores"] = "main",
-    ) -> int:
-        """Acquire one image from the preview stream and return its size"""
-        stream = (
-            self.lores_mjpeg_stream if stream_name == "lores" else self.mjpeg_stream
-        )
-        return portal.call(stream.next_frame_size)
-
-
-class CameraStub(BaseCamera):
     """A stub for a camera, to allow dependencies
 
 
@@ -158,8 +45,11 @@ class CameraStub(BaseCamera):
     This stub class should be used for dependencies on the CameraProtocol.
     """
 
+    mjpeg_stream = MJPEGStreamDescriptor()
+    lores_mjpeg_stream = MJPEGStreamDescriptor()
+
     def __enter__(self) -> None:
-        raise NotImplementedError("Cameras must not inherit from CameraStub")
+        raise NotImplementedError("CameraThings must define their own __enter__ method")
 
     def __exit__(self, _exc_type, _exc_value, _traceback) -> None:
         raise NotImplementedError("Cameras must not inherit from CameraStub")
@@ -169,11 +59,6 @@ class CameraStub(BaseCamera):
         "Whether the MJPEG stream is active"
         raise NotImplementedError("Cameras must not inherit from CameraStub")
 
-    @thing_action
-    def snap_image(self) -> NDArray:
-        """Acquire one image from the camera."""
-        raise NotImplementedError("Cameras must not inherit from CameraStub")
-
     @thing_action
     def capture_array(
         self,
@@ -204,5 +89,5 @@ class CameraStub(BaseCamera):
         raise NotImplementedError("Cameras must not inherit from CameraStub")
 
 
-CameraDependency = direct_thing_client_dependency(CameraStub, "/camera/")
-RawCameraDependency = raw_thing_dependency(CameraProtocol)
+CameraDependency = direct_thing_client_dependency(BaseCamera, "/camera/")
+RawCameraDependency = raw_thing_dependency(BaseCamera)