reveal element filters and drawing underlay panels just if drawing is active

Those two panels were requiring drawing's camera to be active object which was a bit confusing since "Active Drawing" section above worked fine without selecting camera explicitly.

https://i.imgur.com/wcmA73Z.png

src/bonsai/bonsai/bim/module/drawing/operator.py

@@ -1779,7 +1779,7 @@ class SaveDrawingStyle(bpy.types.Operator, tool.Ifc.Operator):
         if self.index:
             index = int(self.index)
         else:
-            index = context.active_object.data.BIMCameraProperties.active_drawing_style_index
+            index = context.scene.camera.data.BIMCameraProperties.active_drawing_style_index
         scene.DocProperties.drawing_styles[index].raster_style = json.dumps(style)
 
         bpy.ops.bim.save_drawing_styles_data()
@@ -2678,8 +2678,9 @@ class EditElementFilter(bpy.types.Operator, tool.Ifc.Operator):
     filter_mode: bpy.props.StringProperty()
 
     def _execute(self, context):
-        props = context.active_object.data.BIMCameraProperties
         obj = bpy.context.scene.camera
+        assert obj
+        props = obj.data.BIMCameraProperties
         element = tool.Ifc.get_entity(obj)
         pset = tool.Pset.get_element_pset(element, "EPset_Drawing")
         if self.filter_mode == "INCLUDE":

src/bonsai/bonsai/bim/module/drawing/ui.py

@@ -106,11 +106,7 @@ class BIM_PT_element_filters(Panel):
 
     @classmethod
     def poll(cls, context):
-        return (
-            context.scene.camera
-            and context.active_object
-            and hasattr(context.active_object.data, "BIMCameraProperties")
-        )
+        return bool((camera := context.scene.camera) and tool.Ifc.get_entity(camera))
 
     def draw(self, context):
         if not ElementFiltersData.is_loaded:
@@ -160,17 +156,15 @@ class BIM_PT_drawing_underlay(Panel):
 
     @classmethod
     def poll(cls, context):
-        return (
-            context.scene.camera
-            and context.active_object
-            and hasattr(context.active_object.data, "BIMCameraProperties")
-        )
+        return bool((camera := context.scene.camera) and tool.Ifc.get_entity(camera))
 
     def draw(self, context):
         layout = self.layout
         layout.use_property_split = True
+        camera = context.scene.camera
+        assert camera
         dprops = context.scene.DocProperties
-        props = context.active_object.data.BIMCameraProperties
+        props = camera.data.BIMCameraProperties
         drawing_index_is_valid = props.active_drawing_style_index < len(dprops.drawing_styles)
 
         if not DrawingsData.is_loaded: