Migrate to new Blob type and update imports

This now uses the latest version of labthings-fastapi.

pyproject.toml

@@ -15,7 +15,7 @@ classifiers = [
   "Operating System :: OS Independent",
 ]
 dependencies = [
-  "labthings-fastapi[server] == 0.0.6",
+  "labthings-fastapi[server] == 0.0.7",
   "labthings-sangaboard",
   "camera-stage-mapping ~= 0.1.6",
   "numpy ~= 1.20",
@@ -31,7 +31,7 @@ dev = [
   "labthings-fastapi[dev]",
 ]
 pi = [
-  "labthings-picamera2 == 0.0.1-dev1",
+  "labthings-picamera2 == 0.0.1-dev2",
 ]
 
 [project.scripts]

src/openflexure_microscope_server/things/camera/__init__.py

@@ -14,15 +14,35 @@ from labthings_fastapi.decorators import thing_action, thing_property
 from labthings_fastapi.dependencies.metadata import GetThingStates
 from labthings_fastapi.dependencies.blocking_portal import BlockingPortal
 from labthings_fastapi.outputs.mjpeg_stream import MJPEGStreamDescriptor
-from labthings_fastapi.outputs.blob import BlobOutput
+from labthings_fastapi.outputs.blob import blob_type
 from labthings_fastapi.types.numpy import NDArray
 
 
-class JPEGBlob(BlobOutput):
+JPEGBlob = blob_type("image/jpeg")
-    media_type = "image/jpeg"
+
+class CameraMeta:
+    def __subclasscheck__(cls, C):
+        """Override Python's default behaviour and use duck typing"""
+        print(f"Checking if {C} is a camera...")
+        for action in ["snap_image", "capture_array", "capture_jpeg", "grab_jpeg", "grab_jpeg_size"]:
+            a = getattr(C, action, None)
+            if not callable(a):
+                return False
+        for prop in ["stream_active"]:
+            if not hasattr(C, prop):
+                return False
+        for k in ["mjpeg_stream", "lores_mjpeg_stream"]:
+            stream = getattr(C, k)
+            if not isinstance(stream, MJPEGStreamDescriptor):
+                return False
+        return True
+
+    def __instancecheck__(cls, I):
+        return cls.__subclasscheck__(I)
 
 
 class Camera(Thing):
+    __metaclass__ = CameraMeta
     """A Thing representing a camera"""
 
     def __enter__(self):
@@ -104,3 +124,4 @@ class Camera(Thing):
             self.lores_mjpeg_stream if stream_name == "lores" else self.mjpeg_stream
         )
         return portal.call(stream.next_frame_size)
+

src/openflexure_microscope_server/things/camera/opencv.py

@@ -19,14 +19,9 @@ from labthings_fastapi.utilities import get_blocking_portal
 from labthings_fastapi.decorators import thing_action, thing_property
 from labthings_fastapi.dependencies.metadata import GetThingStates
 from labthings_fastapi.outputs.mjpeg_stream import MJPEGStreamDescriptor
-from labthings_fastapi.outputs.blob import BlobOutput
 from labthings_fastapi.types.numpy import NDArray
 
-from . import Camera
+from . import Camera, JPEGBlob
-
-
-class JPEGBlob(BlobOutput):
-    media_type = "image/jpeg"
 
 
 class OpenCVCamera(Camera):

src/openflexure_microscope_server/things/settings_manager.py

@@ -13,7 +13,8 @@ from fastapi import Depends, HTTPException, Request
 from labthings_fastapi.dependencies.metadata import GetThingStates
 from labthings_fastapi.thing import Thing
 from labthings_fastapi.decorators import thing_action, thing_property
-from labthings_fastapi.server import find_thing_server, ThingServer
+from labthings_fastapi.dependencies.thing_server import find_thing_server
+from labthings_fastapi.server import ThingServer
 from labthings_fastapi.dependencies.invocation import InvocationLogger
 
 

src/openflexure_microscope_server/things/smart_scan.py

@@ -27,7 +27,7 @@ from labthings_fastapi.dependencies.metadata import GetThingStates
 from labthings_fastapi.dependencies.thing import direct_thing_client_dependency
 from labthings_fastapi.dependencies.invocation import CancelHook, InvocationLogger, InvocationCancelledError
 from labthings_fastapi.decorators import thing_action, thing_property, fastapi_endpoint
-from labthings_fastapi.outputs.blob import BlobOutput
+from labthings_fastapi.outputs.blob import blob_type
 from .camera import Camera
 from .stage import Stage
 from openflexure_microscope_server.things.autofocus import AutofocusThing
@@ -335,11 +335,8 @@ DOWNLOADABLE_SCAN_FILES = (
     "images.zip",
 )
 
-class JPEGBlob(BlobOutput):
+JPEGBlob = blob_type("image/jpeg")
-    media_type = "image/jpeg"
+ZipBlob = blob_type("application/zip")
-
-class ZipBlob(BlobOutput):
-    media_type = "application/zip"
 
 class SmartScanThing(Thing):
     def __init__(self, path_to_openflexure_stitch: str):

src/openflexure_microscope_server/things/stitching.py

@@ -6,15 +6,14 @@ from labthings_fastapi.thing import Thing
 from labthings_fastapi.dependencies.raw_thing import raw_thing_dependency
 from labthings_fastapi.dependencies.invocation import InvocationLogger
 from labthings_fastapi.decorators import thing_action
-from labthings_fastapi.outputs.blob import BlobOutput
+from labthings_fastapi.outputs.blob import blob_type
 
 from .smart_scan import SmartScanThing
 
 SmartScanDep = raw_thing_dependency(SmartScanThing)
 
 
-class JPEGBlob(BlobOutput):
+JPEGBlob = blob_type("image/jpeg")
-    media_type = "image/jpeg"
 
 
 class Stitcher(Thing):