Fix #3480 : Scene tabs now show their individual description on hover

Also correct minor typo

src/blenderbim/blenderbim/bim/operator.py

@@ -42,11 +42,14 @@ from math import radians
 
 class SetTab(bpy.types.Operator):
     bl_idname = "bim.set_tab"
-    bl_label = "Set Tab"
+    bl_label = "Set Current Tab"
     bl_options = {"REGISTER", "UNDO"}
-    bl_description = "Sets the current property tab"
     tab: bpy.props.StringProperty()
 
+    @classmethod
+    def description(cls, context, properties):
+        return next((t[1] for t in blenderbim.bim.prop.get_tab(None, context) if t[0] == properties.tab), "")
+
     def execute(self, context):
         if context.area.spaces.active.search_filter:
             return {"FINISHED"}

src/blenderbim/blenderbim/bim/prop.py

@@ -234,7 +234,7 @@ def get_length_value(self):
     return self.float_value * si_conversion
 
 
-def set_lenght_value(self, value):
+def set_length_value(self, value):
     si_conversion = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
     self.float_value = value / si_conversion
 
@@ -274,7 +274,7 @@ class Attribute(PropertyGroup):
         set=set_float_value,
     )
     length_value: FloatProperty(
-        name="Value", description=tooltip, get=get_length_value, set=set_lenght_value, unit="LENGTH"
+        name="Value", description=tooltip, get=get_length_value, set=set_length_value, unit="LENGTH"
     )
     enum_items: StringProperty(name="Value")
     enum_descriptions: CollectionProperty(type=StrProperty)