New usecase for adding conversion based units

src/blenderbim/blenderbim/tool/__init__.py

@@ -25,3 +25,4 @@ from blenderbim.tool.ifc import Ifc
 from blenderbim.tool.owner import Owner
 from blenderbim.tool.style import Style
 from blenderbim.tool.surveyor import Surveyor
+from blenderbim.tool.unit import Unit

src/blenderbim/blenderbim/tool/unit.py

@@ -0,0 +1,157 @@
+# BlenderBIM Add-on - OpenBIM Blender Add-on
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of BlenderBIM Add-on.
+#
+# BlenderBIM Add-on is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# BlenderBIM Add-on is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
+
+import bpy
+import json
+import ifcopenshell
+import blenderbim.core.tool
+import blenderbim.tool as tool
+
+
+class Unit(blenderbim.core.tool.Unit):
+    @classmethod
+    def clear_active_unit(cls):
+        bpy.context.scene.BIMUnitProperties.active_unit_id = 0
+
+    @classmethod
+    def disable_editing_units(cls):
+        bpy.context.scene.BIMUnitProperties.is_editing = False
+
+    @classmethod
+    def enable_editing_units(cls):
+        bpy.context.scene.BIMUnitProperties.is_editing = True
+
+    @classmethod
+    def export_unit_attributes(cls):
+        def callback(attributes, prop):
+            if prop.name == "Dimensions":
+                try:
+                    attributes[prop.name] = json.loads(prop.get_value())
+                except:
+                    attributes[prop.name] = (0, 0, 0, 0, 0, 0, 0)
+                return True
+
+        props = bpy.context.scene.BIMUnitProperties
+        return blenderbim.bim.helper.export_attributes(props.unit_attributes, callback=callback)
+
+    @classmethod
+    def get_scene_unit_name(cls, unit_type):
+        props = bpy.context.scene.unit_settings
+        is_metric = props.system == "METRIC" or props.system == "NONE"
+
+        if is_metric:
+            name = "METRE"
+        elif props.length_unit == "MILES":
+            name = "mile"
+        elif props.length_unit == "FEET" or props.length_unit == "ADAPTIVE":
+            name = "foot"
+        elif props.length_unit == "INCHES":
+            name = "inch"
+        elif props.length_unit == "THOU":
+            name = "thou"
+
+        if unit_type == "length":
+            return name
+        elif unit_type == "area":
+            if is_metric:
+                return f"SQUARE_{name}"
+            return f"square {name}"
+        elif unit_type == "volume":
+            if is_metric:
+                return f"CUBIC_{name}"
+            return f"cubic {name}"
+
+    @classmethod
+    def get_scene_unit_si_prefix(cls):
+        props = bpy.context.scene.unit_settings
+        if props.length_unit == "ADAPTIVE" or props.length_unit == "METERS":
+            return
+        return props.length_unit.replace("METERS", "")
+
+    @classmethod
+    def get_si_name_from_unit_type(cls, unit_type):
+        return ifcopenshell.util.unit.si_type_names.get(unit_type, None)
+
+    @classmethod
+    def get_unit_class(cls, unit):
+        return unit.is_a()
+
+    @classmethod
+    def import_unit_attributes(cls, unit):
+        def callback(name, prop, data):
+            if name == "Dimensions" and data["type"] != "IfcSIUnit":
+                new = bpy.context.scene.BIMUnitProperties.unit_attributes.add()
+                new.name = name
+                new.is_null = data[name] is None
+                new.is_optional = False
+                new.data_type = "string"
+                new.string_value = json.dumps([e for e in tool.Ifc.get().by_id(data["id"]).Dimensions])
+                return True
+
+        props = bpy.context.scene.BIMUnitProperties
+        props.unit_attributes.clear()
+        blenderbim.bim.helper.import_attributes2(unit, props.unit_attributes, callback=callback)
+
+    @classmethod
+    def import_units(cls):
+        props = bpy.context.scene.BIMUnitProperties
+        props.units.clear()
+
+        units = []
+        for unit_class in ["IfcDerivedUnit", "IfcMonetaryUnit", "IfcNamedUnit"]:
+            units += tool.Ifc.get().by_type(unit_class)
+
+        assigned_units = tool.Ifc.get().by_type("IfcUnitAssignment")
+        if assigned_units:
+            assigned_units = assigned_units[0].Units
+
+        for unit in units:
+            name = ""
+            if unit.is_a("IfcMonetaryUnit"):
+                name = unit.Currency
+            elif not unit.is_a("IfcDerivedUnit"):
+                name = unit.Name or ""
+
+            if unit.is_a("IfcSIUnit") and unit.Prefix:
+                if "_" in name:
+                    name_components = name.split("_")
+                    name = f"{name_components[0]} {unit.Prefix}{name_components[1]}"
+                else:
+                    name = f"{unit.Prefix}{name}"
+
+            if unit.is_a("IfcMonetaryUnit"):
+                unit_type = "CURRENCY"
+            else:
+                unit_type = getattr(unit, "UserDefinedType", None)
+                if not unit_type:
+                    unit_type = getattr(unit, "UnitType", None)
+
+            new = props.units.add()
+            new.ifc_definition_id = unit.id()
+            new.name = name
+            new.unit_type = unit_type
+            new.is_assigned = unit in assigned_units
+            new.ifc_class = unit.is_a()
+
+    @classmethod
+    def is_scene_unit_metric(cls):
+        return bpy.context.scene.unit_settings.system in ["METRIC", "NONE"]
+
+    @classmethod
+    def set_active_unit(cls, unit):
+        bpy.context.scene.BIMUnitProperties.active_unit_id = unit.id()