Displaying project units for length values in psets and qsets

Examples:
- https://i.imgur.com/ww7MJ7w.png
- https://i.imgur.com/N1rOELc.png

src/blenderbim/blenderbim/bim/module/pset/operator.py

@@ -133,6 +133,14 @@ class EnablePsetEditing(bpy.types.Operator):
         metadata.has_calculator = bool(mapper.get(pset_template.Name, {}).get(prop_template.Name, None))
         metadata.data_type = self.get_data_type(prop_template)
 
+        special_type = ""
+        if prop_template.PrimaryMeasureType in (
+            "IfcPositiveLengthMeasure",
+            "IfcLengthMeasure",
+        ) or prop_template.TemplateType in ("Q_LENGTH",):
+            special_type = "LENGTH"
+        metadata.special_type = special_type
+
         if metadata.data_type == "string":
             metadata.string_value = "" if metadata.is_null else str(data[prop_template.Name])
         elif metadata.data_type == "integer":
@@ -196,7 +204,7 @@ class EnablePsetEditing(bpy.types.Operator):
 
                 enum_items = [v.wrappedValue for v in prop.EnumerationReference.EnumerationValues]
                 selected_enum_items = [v.wrappedValue for v in prop.EnumerationValues]
-                data_type = metadata.get_value_name()
+                data_type = metadata.get_value_name(display_only=True)
 
                 for enum in enum_items:
                     new = simple_prop.enumerated_value.enumerated_values.add()
@@ -352,7 +360,9 @@ class AddPset(bpy.types.Operator, Operator):
                 continue
             element = tool.Ifc.get().by_id(ifc_definition_id)
             if pset_name in blenderbim.bim.schema.ifc.psetqto.get_applicable_names(element.is_a(), pset_only=True):
-                bpy.ops.bim.enable_pset_editing(pset_id=0, pset_name=pset_name, pset_type="PSET", obj=obj, obj_type=self.obj_type)
+                bpy.ops.bim.enable_pset_editing(
+                    pset_id=0, pset_name=pset_name, pset_type="PSET", obj=obj, obj_type=self.obj_type
+                )
 
 
 class AddQto(bpy.types.Operator, Operator):
@@ -368,7 +378,9 @@ class AddQto(bpy.types.Operator, Operator):
         props = get_pset_props(context, self.obj, self.obj_type)
         ifc_definition_id = blenderbim.bim.helper.get_obj_ifc_definition_id(context, self.obj, self.obj_type)
         element = tool.Ifc.get().by_id(ifc_definition_id)
-        bpy.ops.bim.enable_pset_editing(pset_id=0, pset_name=props.qto_name, pset_type="QTO", obj=self.obj, obj_type=self.obj_type)
+        bpy.ops.bim.enable_pset_editing(
+            pset_id=0, pset_name=props.qto_name, pset_type="QTO", obj=self.obj, obj_type=self.obj_type
+        )
 
 
 class CalculateQuantity(bpy.types.Operator):

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

@@ -42,7 +42,7 @@ def draw_property(prop, layout, copy_operator=None):
 
 
 def draw_single_property(prop, layout, copy_operator=None):
-    value_name = prop.metadata.get_value_name()
+    value_name = prop.metadata.get_value_name(display_only=True)
     if not value_name:
         layout.label(text=prop["Name"])
         return

src/blenderbim/blenderbim/bim/prop.py

@@ -223,6 +223,16 @@ def set_numerical_value(self, value_name, new_value):
     self[value_name] = new_value
 
 
+def get_length_value(self):
+    si_conversion = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
+    return self.float_value * si_conversion
+
+
+def set_lenght_value(self, value):
+    si_conversion = ifcopenshell.util.unit.calculate_unit_scale(tool.Ifc.get())
+    self.float_value = value / si_conversion
+
+
 class Attribute(PropertyGroup):
     tooltip = "`Right Click > IFC Description` to read the attribute description and online documentation"
     name: StringProperty(name="Name")
@@ -245,6 +255,9 @@ class Attribute(PropertyGroup):
         get=lambda self: float(self.get("float_value", 0.0)),
         set=set_float_value,
     )
+    length_value: FloatProperty(
+        name="Value", description=tooltip, get=get_length_value, set=set_lenght_value, unit="LENGTH"
+    )
     enum_items: StringProperty(name="Value")
     enum_descriptions: CollectionProperty(type=StrProperty)
     enum_value: EnumProperty(items=get_attribute_enum_values, name="Value", update=update_attribute_value)
@@ -257,6 +270,7 @@ class Attribute(PropertyGroup):
     value_min_constraint: BoolProperty(default=False, description="True if the numerical value has a lower bound")
     value_max: FloatProperty(description="This is used to validate int_value and float_value")
     value_max_constraint: BoolProperty(default=False, description="True if the numerical value has an upper bound")
+    special_type: StringProperty(name="Special Value Type", default="")
 
     def get_value(self):
         if self.is_optional and self.is_null:
@@ -275,7 +289,7 @@ class Attribute(PropertyGroup):
         elif self.data_type == "enum":
             return "0"
 
-    def get_value_name(self):
+    def get_value_name(self, display_only=False):
         if self.data_type == "string":
             return "string_value"
         elif self.data_type == "boolean":
@@ -283,6 +297,8 @@ class Attribute(PropertyGroup):
         elif self.data_type == "integer":
             return "int_value"
         elif self.data_type == "float":
+            if display_only and self.special_type == "LENGTH":
+                return "length_value"
             return "float_value"
         elif self.data_type == "enum":
             return "enum_value"