tweaked active operator

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

@@ -102,6 +102,11 @@ def draw_psetqto_ui(
     allow_removing: bool = True,
     filter_keyword: str = "",
 ) -> None:
+
+
+    active_operator = context.active_operator
+    
+
     filter_keyword = filter_keyword.lower()
     box = layout.box()
     row = box.row(align=True)
@@ -195,7 +200,12 @@ def draw_psetqto_ui(
                 row.label(text=prop["Name"])
                 op = row.operator("bim.select_similar", text=nominal_value, icon="NONE", emboss=False)
                 op.key = '"' + pset["Name"].replace('"', '\\"') + '"."' + prop["Name"].replace('"', '\\"') + '"'
-
+                # calculate sum of all selected objects
+                if active_operator:
+                    if active_operator.bl_idname == "BIM_OT_select_similar":
+                        calculated_sum = getattr(active_operator, "calculated_sum", 0.0)
+                        if op.key == active_operator.key and calculated_sum != 0 and isinstance(float(nominal_value), (int, float)):
+                            row.label(text=f"(Sum: {calculated_sum})")
             if not has_props_displayed:
                 row = box.row()
                 row.scale_y = 0.8

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

@@ -696,8 +696,19 @@ class SelectSimilar(Operator, tool.Ifc.Operator):
     bl_idname = "bim.select_similar"
     bl_label = "Select Similar"
     bl_options = {"REGISTER", "UNDO"}
+    bl_description = (
+        "Select objects with a similar value\n\n"
+        + "SHIFT+CLICK display the sum of all selected objects"
+    )
 
     key: bpy.props.StringProperty()
+    calculate_sum: bpy.props.BoolProperty(name="Calculate Sum of Selected Objects", default=False, options={"SKIP_SAVE"})
+    calculated_sum: bpy.props.FloatProperty(name="Calculated Sum", default=0.0)
+
+    def invoke(self, context, event):
+        if event.type == "LEFTMOUSE" and event.shift:
+            self.calculate_sum = True
+        return self.execute(context)
 
     def _execute(self, context):
         props = context.scene.BIMSearchProperties
@@ -707,9 +718,26 @@ class SelectSimilar(Operator, tool.Ifc.Operator):
         if key == "PredefinedType":
             key = "predefined_type"
         value = ifcopenshell.util.selector.get_element_value(element, key)
-        for obj in context.visible_objects:
-            element = tool.Ifc.get_entity(obj)
-            if not element:
-                continue
-            if ifcopenshell.util.selector.get_element_value(element, key) == value:
-                obj.select_set(True)
+
+
+        if self.calculate_sum and isinstance(value, (int, float)):
+            total = 0
+            for obj in context.selected_objects:
+                element = tool.Ifc.get_entity(obj)
+                if not element:
+                    continue
+                value = ifcopenshell.util.selector.get_element_value(element, key)
+                if value:
+                    total += value
+            self.calculated_sum = total
+            bpy.context.window_manager.clipboard = str(self.calculated_sum)
+            self.report({"INFO"}, f"({self.calculated_sum}) was copied to the clipboard.")
+        else:
+            self.calculated_sum = 0
+            for obj in context.visible_objects:
+                element = tool.Ifc.get_entity(obj)
+                if not element:
+                    continue
+                if ifcopenshell.util.selector.get_element_value(element, key) == value:
+                    obj.select_set(True)
+