First attempt at ripping out agnostic code into ifcopenshell.api namespace. See #1399.

src/ifcopenshell-python/ifcopenshell/api/georeference/add_georeferencing.py

@@ -0,0 +1,20 @@
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+
+    def execute(self):
+        source_crs = None
+        for context in self.file.by_type("IfcGeometricRepresentationContext", include_subtypes=False):
+            if context.ContextType == "Model":
+                source_crs = context
+                break
+        if not source_crs:
+            return
+        projected_crs = self.file.create_entity("IfcProjectedCRS", **{"Name": ""})
+        self.file.create_entity("IfcMapConversion", **{
+            "SourceCRS": source_crs,
+            "TargetCRS": projected_crs,
+            "Eastings": 0,
+            "Northings": 0,
+            "OrthogonalHeight": 0,
+        })

src/ifcopenshell-python/ifcopenshell/api/georeference/data.py

@@ -0,0 +1,31 @@
+class Data:
+    is_loaded = False
+    map_conversion = {}
+    projected_crs = {}
+
+    @classmethod
+    def purge(cls):
+        cls.is_loaded = False
+        cls.map_conversion = {}
+        cls.projected_crs = {}
+
+    @classmethod
+    def load(cls, file):
+        if not file:
+            return
+        cls.map_conversion = {}
+        cls.projected_crs = {}
+        if file.schema == "IFC2X3":
+            return
+        for context in file.by_type("IfcGeometricRepresentationContext", include_subtypes=False):
+            if not context.HasCoordinateOperation:
+                continue
+            map_conversion = context.HasCoordinateOperation[0]
+            cls.map_conversion = map_conversion.get_info()
+            cls.map_conversion["SourceCRS"] = cls.map_conversion["SourceCRS"].id()
+            cls.map_conversion["TargetCRS"] = cls.map_conversion["TargetCRS"].id()
+            cls.projected_crs = map_conversion.TargetCRS.get_info()
+            if cls.projected_crs["MapUnit"]:
+                cls.projected_crs["MapUnit"] = map_conversion.TargetCRS.MapUnit.get_info()
+            break
+        cls.is_loaded = True

src/ifcopenshell-python/ifcopenshell/api/georeference/edit_georeferencing.py

@@ -0,0 +1,52 @@
+import ifcopenshell.util.unit
+
+
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+        self.settings = {
+            "map_conversion": {},
+            "projected_crs": {},
+            "map_unit": "",
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        map_conversion = self.file.by_type("IfcMapConversion")[0]
+        projected_crs = self.file.by_type("IfcProjectedCRS")[0]
+        for name, value in self.settings["map_conversion"].items():
+            setattr(map_conversion, name, value)
+        for name, value in self.settings["projected_crs"].items():
+            setattr(projected_crs, name, value)
+        self.remove_existing_map_unit(projected_crs)
+        self.set_map_unit(projected_crs)
+
+    def remove_existing_map_unit(self, projected_crs):
+        if projected_crs.MapUnit and len(self.file.get_inverse(projected_crs.MapUnit)) == 1:
+            # TODO: go deeper for conversion units
+            self.file.remove(projected_crs.MapUnit)
+
+    def set_map_unit(self, projected_crs):
+        if not self.settings["map_unit"]:
+            return
+
+        if "METRE" in self.settings["map_unit"]:
+            projected_crs.MapUnit = self.file.createIfcSIUnit(
+                None,
+                "LENGTHUNIT",
+                ifcopenshell.util.unit.get_prefix(self.settings["map_unit"]),
+                ifcopenshell.util.unit.get_unit_name(self.settings["map_unit"]),
+            )
+            return
+
+        value_component = self.file.create_entity(
+            "IfcReal", **{"wrappedValue": ifcopenshell.util.unit.si_conversions[self.settings["map_unit"]]}
+        )
+        si_unit = self.file.createIfcSIUnit(None, "LENGTHUNIT", None, "METRE")
+        projected_crs.MapUnit = self.file.createIfcConversionBasedUnit(
+            self.file.createIfcDimensionalExponents(1, 0, 0, 0, 0, 0, 0),
+            "LENGTHUNIT",
+            self.settings["map_unit"],
+            self.file.createIfcMeasureWithUnit(value_component, si_unit),
+        )

src/ifcopenshell-python/ifcopenshell/api/georeference/remove_georeferencing.py

@@ -0,0 +1,12 @@
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+
+    def execute(self):
+        map_conversion = self.file.by_type("IfcMapConversion")[0]
+        projected_crs = self.file.by_type("IfcProjectedCRS")[0]
+        if projected_crs.MapUnit and len(self.file.get_inverse(projected_crs.MapUnit)) == 1:
+            # TODO: go deeper for conversion units
+            self.file.remove(projected_crs.MapUnit)
+        self.file.remove(projected_crs)
+        self.file.remove(map_conversion)