Cleaned up camera locks

openflexure_microscope/camera/pi.py

@@ -240,9 +240,11 @@ class StreamingCamera(BaseCamera):
     def start_preview(self, fullscreen=True, window=None) -> bool:
         """Start the on board GPU camera preview."""
         logging.info("Starting the GPU preview")
-        self.start_stream_recording()
+
+        # TODO: Commented out as I honestly can't remember why this was here. May need to put back?
+        #self.start_stream_recording() 
+
         try:
-            with self.lock:
             if not self.camera.preview:
                 logging.debug("Starting preview")
                 self.camera.start_preview(fullscreen=fullscreen, window=window)
@@ -257,14 +259,11 @@ class StreamingCamera(BaseCamera):
             logging.error("Suppressed a MMALError in start_preview. Exception: {}".format(e))
         except picamera.exc.PiCameraValueError as e:
             logging.error("Suppressed a ValueError exception in start_preview. Exception: {}".format(e))
-        return True
 
     def stop_preview(self) -> bool:
         """Stop the on board GPU camera preview."""
-        with self.lock:
         self.camera.stop_preview()
         self.state['preview_active'] = False
-        return True
 
     def start_recording(
             self,
@@ -340,6 +339,7 @@ class StreamingCamera(BaseCamera):
             splitter_port (int): Splitter port to stop recording on
             resolution ((int, int)): Resolution to set the camera to, after stopping recording.
         """
+        with self.lock:
             # If no resolution is specified, default to image_resolution
             if not resolution:
                 resolution = self.config['image_resolution']
@@ -367,6 +367,7 @@ class StreamingCamera(BaseCamera):
             splitter_port (int): Splitter port to start recording on
             resolution ((int, int)): Resolution to set the camera to, before starting recording. Defaults to `self.config['stream_resolution']`.
         """
+        with self.lock:
             # If stream object was destroyed
             if not hasattr(self, 'stream'):
                 self.stream = io.BytesIO()  # Create a stream object