cost items ui - update current index on item deletion

To make it less awkward to remove multiple items starting from the last.

Before - https://files.catbox.moe/wce56c.mp4
After - https://files.catbox.moe/wv1jhs.mp4

src/bonsai/bonsai/bim/module/classification/data.py

@@ -161,7 +161,10 @@ class CostClassificationsData(ReferencesData):
     def references(cls) -> list[dict[str, Any]]:
         results: list[dict[str, Any]] = []
         props = tool.Cost.get_cost_props()
-        element = tool.Ifc.get().by_id(props.cost_items[props.active_cost_item_index].ifc_definition_id)
+        active_cost_item = props.active_cost_item
+        if not active_cost_item:
+            return results
+        element = tool.Ifc.get().by_id(active_cost_item.ifc_definition_id)
         if element:
             for reference in ifcopenshell.util.classification.get_references(element):
                 data = reference.get_info()

src/bonsai/bonsai/bim/module/cost/prop.py

@@ -34,7 +34,7 @@ from bpy.props import (
     FloatVectorProperty,
     CollectionProperty,
 )
-from typing import TYPE_CHECKING, Literal
+from typing import TYPE_CHECKING, Literal, Union
 
 
 def get_schedule_of_rates(self: "BIMCostProperties", context: bpy.types.Context) -> tool.Blender.BLENDER_ENUM_ITEMS:
@@ -345,3 +345,7 @@ class BIMCostProperties(PropertyGroup):
         currency: str
         custom_currency: str
         cost_schedule_files: bpy.types.bpy_prop_collection_idprop[CostItemsMapping]
+
+    @property
+    def active_cost_item(self) -> Union[CostItem, None]:
+        return tool.Blender.get_active_uilist_element(self.cost_items, self.active_cost_item_index)

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

@@ -106,8 +106,7 @@ class RemoveProfileDef(bpy.types.Operator, tool.Ifc.Operator):
         bpy.ops.bim.load_profiles()
 
         # preserve selected index if possible
-        if props.profiles:
-            props.active_profile_index = min(current_index, len(props.profiles) - 1)
+        props.active_profile_index = tool.Blender.get_valid_uilist_index(props.active_profile_index, props.profiles)
 
 
 class EnableEditingProfile(bpy.types.Operator):

src/bonsai/bonsai/tool/blender.py

@@ -42,7 +42,7 @@ from mathutils import Vector
 from pathlib import Path
 from functools import lru_cache, cache
 from bonsai.bim.ifc import IFC_CONNECTED_TYPE
-from typing import Any, Optional, Union, Literal, Iterable, Callable, TypeVar, Generator, TYPE_CHECKING, Sequence
+from typing import Any, Optional, Union, Literal, Iterable, Callable, TypeVar, Generator, TYPE_CHECKING, Sequence, Sized
 from typing_extensions import assert_never
 
 if TYPE_CHECKING:
@@ -1692,6 +1692,14 @@ class Blender(bonsai.core.tool.Blender):
             return collection[index]
         return None
 
+    @classmethod
+    def get_valid_uilist_index(cls, current_index: int, items: Sized) -> int:
+        """
+        Method to help maintaining item selection after some uilist item was removed
+        and items were reloaded.
+        """
+        return max(0, min(current_index, len(items) - 1))
+
     @classmethod
     def clear_undo_history(cls) -> None:
         """Clears the Blender history, Bonsai history, and IfcOpenShell history"""

src/bonsai/bonsai/tool/cost.py

@@ -168,6 +168,9 @@ class Cost(bonsai.core.tool.Cost):
             for rel in cost_schedule.Controls or []
             for cost_item in rel.RelatedObjects or []
         ]
+        props.active_cost_item_index = tool.Blender.get_valid_uilist_index(
+            props.active_cost_item_index, props.cost_items
+        )
         props.is_cost_update_enabled = True
 
     @classmethod
@@ -208,6 +211,7 @@ class Cost(bonsai.core.tool.Cost):
 
     @classmethod
     def clean_up_cost_item_tree(cls, cost_item_id: int) -> None:
+        """Clean up cost item tree after ``cost_item_id`` was deleted."""
         props = cls.get_cost_props()
         if not hasattr(cls, "contracted_cost_items"):
             cls.contracted_cost_items = json.loads(props.contracted_cost_items)

src/bonsai/bonsai/tool/spatial.py

@@ -475,7 +475,7 @@ class Spatial(bonsai.core.tool.Spatial):
         props.containers.clear()
         cls.contracted_containers = json.loads(props.contracted_containers)
         cls.import_spatial_element(tool.Ifc.get().by_type("IfcProject")[0], 0)
-        props.active_container_index = min(previous_container_index, len(props.containers) - 1)
+        props.active_container_index = tool.Blender.get_valid_uilist_index(previous_container_index, props.containers)
 
     @classmethod
     def import_spatial_element(cls, element: ifcopenshell.entity_instance, level_index: int) -> None: