WIP

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

@@ -187,10 +187,11 @@ class ALIGN_OT_add_alignment(Operator, tool.Ifc.Operator):
     bl_options = {"REGISTER", "UNDO"}
 
     alignment_name: StringProperty(name="Name", default="Alignment")
-    start_station: FloatProperty(
+    start_station: StringProperty(
         name="Start Station",
-        description="Station value at the start of the alignment (distance along 0)",
-        default=0.0,
+        description="Station value at the start of the alignment (distance along 0). "
+        "Accepts a plain number or stationing notation, e.g. 10+00 or 1+000",
+        default="0",
     )
 
     @classmethod
@@ -202,7 +203,13 @@ class ALIGN_OT_add_alignment(Operator, tool.Ifc.Operator):
 
     def _execute(self, context):
         try:
-            alignment = core.create_alignment(tool.Ifc, tool.Alignment, self.alignment_name, self.start_station)
+            start_station = tool.Alignment.parse_station(self.start_station)
+        except ValueError as e:
+            self.report({"ERROR"}, f"Invalid start station: {e}")
+            return {"CANCELLED"}
+
+        try:
+            alignment = core.create_alignment(tool.Ifc, tool.Alignment, self.alignment_name, start_station)
         except ValueError as e:
             self.report({"ERROR"}, str(e))
             return {"CANCELLED"}
@@ -275,7 +282,11 @@ class ALIGN_OT_set_start_station(Operator, tool.Ifc.Operator):
     bl_description = "Change the alignment's start station"
     bl_options = {"REGISTER", "UNDO"}
 
-    station: FloatProperty(name="Start Station", default=0.0)
+    station: StringProperty(
+        name="Start Station",
+        description="Accepts a plain number or stationing notation, e.g. 10+00 or 1+000",
+        default="0",
+    )
 
     @classmethod
     def poll(cls, context):
@@ -288,23 +299,30 @@ class ALIGN_OT_set_start_station(Operator, tool.Ifc.Operator):
 
     def invoke(self, context, event):
         alignment = tool.Alignment.get_active_alignment()
-        self.station = ifcopenshell.api.alignment.get_alignment_start_station(tool.Ifc.get(), alignment) or 0.0
+        current = ifcopenshell.api.alignment.get_alignment_start_station(tool.Ifc.get(), alignment) or 0.0
+        self.station = tool.Alignment.format_station(current)
         return context.window_manager.invoke_props_dialog(self)
 
     def _execute(self, context):
+        try:
+            station = tool.Alignment.parse_station(self.station)
+        except ValueError as e:
+            self.report({"ERROR"}, f"Invalid station: {e}")
+            return {"CANCELLED"}
+
         alignment = tool.Alignment.get_active_alignment()
         start_referent = tool.Alignment.find_stationing_referent_at(alignment, 0.0)
         if start_referent is None:
             # No stationing at all yet (e.g. an alignment from before this
             # feature existed) -- add the start referent rather than error.
             start_referent = ifcopenshell.api.alignment.add_stationing_referent(
-                tool.Ifc.get(), tool.Alignment.format_station(self.station), alignment, 0.0, self.station
+                tool.Ifc.get(), tool.Alignment.format_station(station), alignment, 0.0, station
             )
         else:
-            tool.Alignment.set_stationing_referent_station(start_referent, self.station)
+            tool.Alignment.set_stationing_referent_station(start_referent, station)
         tool.Alignment.create_object_for_referent(start_referent)
         alignment_decorator.AlignmentSegmentDecorator.refresh()
-        self.report({"INFO"}, f"Start station set to {tool.Alignment.format_station(self.station)}")
+        self.report({"INFO"}, f"Start station set to {tool.Alignment.format_station(station)}")
         return {"FINISHED"}
 
 
@@ -327,17 +345,19 @@ class _StationEquationFields:
     distance_along: FloatProperty(
         name="Distance Along", description="Distance along the alignment where the equation applies", default=0.0
     )
-    station: FloatProperty(
+    station: StringProperty(
         name="Outgoing Station",
-        description="The station value immediately after this point",
-        default=0.0,
+        description="The station value immediately after this point. Accepts a plain "
+        "number or stationing notation, e.g. 10+00 or 1+000",
+        default="0",
         update=_on_station_equation_station_update,
     )
-    incoming_station: FloatProperty(
+    incoming_station: StringProperty(
         name="Incoming Station",
         description="The station value immediately before this point. Leave equal to Outgoing "
-        "Station (the default) for no gap/overlap",
-        default=0.0,
+        "Station (the default) for no gap/overlap. Accepts a plain number or stationing "
+        "notation, e.g. 10+00 or 1+000",
+        default="0",
     )
     reverse_direction: BoolProperty(
         name="Reverse Stationing Direction",
@@ -345,7 +365,7 @@ class _StationEquationFields:
         default=False,
     )
     # Bookkeeping only, for _on_station_equation_station_update — not shown, not saved.
-    station_snapshot: FloatProperty(options={"HIDDEN", "SKIP_SAVE"}, default=0.0)
+    station_snapshot: StringProperty(options={"HIDDEN", "SKIP_SAVE"}, default="0")
 
     def draw(self, context):
         layout = self.layout
@@ -354,9 +374,19 @@ class _StationEquationFields:
         layout.prop(self, "station")
         layout.prop(self, "reverse_direction")
 
-    @property
-    def _has_gap_or_overlap(self) -> bool:
-        return self.incoming_station != self.station
+    def _parse_stations(self):
+        """Parse the station/incoming_station text fields.
+
+        Returns (station, incoming_station, has_gap_or_overlap) — comparing
+        the parsed values rather than raw text so "1000" and "1+000" (the
+        same station, different notation) don't register as a gap.
+
+        Raises:
+            ValueError: If either field isn't a valid station.
+        """
+        station = tool.Alignment.parse_station(self.station)
+        incoming_station = tool.Alignment.parse_station(self.incoming_station)
+        return station, incoming_station, incoming_station != station
 
 
 class ALIGN_OT_add_station_equation(Operator, tool.Ifc.Operator, _StationEquationFields):
@@ -385,15 +415,21 @@ class ALIGN_OT_add_station_equation(Operator, tool.Ifc.Operator, _StationEquatio
         return context.window_manager.invoke_props_dialog(self)
 
     def _execute(self, context):
+        try:
+            station, incoming_station, has_gap_or_overlap = self._parse_stations()
+        except ValueError as e:
+            self.report({"ERROR"}, f"Invalid station: {e}")
+            return {"CANCELLED"}
+
         alignment = tool.Alignment.get_active_alignment()
-        name = tool.Alignment.format_station(self.station)
+        name = tool.Alignment.format_station(station)
         referent = ifcopenshell.api.alignment.add_stationing_referent(
             tool.Ifc.get(),
             name,
             alignment,
             self.distance_along,
-            self.station,
-            incoming_station=self.incoming_station if self._has_gap_or_overlap else None,
+            station,
+            incoming_station=incoming_station if has_gap_or_overlap else None,
             has_increasing_station=False if self.reverse_direction else None,
         )
         tool.Alignment.create_object_for_referent(referent)
@@ -433,9 +469,10 @@ class ALIGN_OT_edit_station_equation(Operator, tool.Ifc.Operator, _StationEquati
             return {"CANCELLED"}
 
         self.distance_along = _referent_distance_along(referent)
-        self.station = ifcopenshell.util.element.get_pset(referent, name="Pset_Stationing", prop="Station") or 0.0
+        station_val = ifcopenshell.util.element.get_pset(referent, name="Pset_Stationing", prop="Station") or 0.0
+        self.station = tool.Alignment.format_station(station_val)
         incoming = ifcopenshell.util.element.get_pset(referent, name="Pset_Stationing", prop="IncomingStation")
-        self.incoming_station = incoming if incoming is not None else self.station
+        self.incoming_station = tool.Alignment.format_station(incoming if incoming is not None else station_val)
         self.reverse_direction = (
             ifcopenshell.util.element.get_pset(referent, name="Pset_Stationing", prop="HasIncreasingStation") is False
         )
@@ -443,6 +480,12 @@ class ALIGN_OT_edit_station_equation(Operator, tool.Ifc.Operator, _StationEquati
         return context.window_manager.invoke_props_dialog(self)
 
     def _execute(self, context):
+        try:
+            station, incoming_station, has_gap_or_overlap = self._parse_stations()
+        except ValueError as e:
+            self.report({"ERROR"}, f"Invalid station: {e}")
+            return {"CANCELLED"}
+
         ifc = tool.Ifc.get()
         try:
             referent = ifc.by_id(self.referent_id)
@@ -463,14 +506,14 @@ class ALIGN_OT_edit_station_equation(Operator, tool.Ifc.Operator, _StationEquati
             bpy.data.objects.remove(obj, do_unlink=True)
         ifcopenshell.api.run("root.remove_product", ifc, product=referent)
 
-        name = tool.Alignment.format_station(self.station)
+        name = tool.Alignment.format_station(station)
         new_referent = ifcopenshell.api.alignment.add_stationing_referent(
             ifc,
             name,
             alignment,
             self.distance_along,
-            self.station,
-            incoming_station=self.incoming_station if self._has_gap_or_overlap else None,
+            station,
+            incoming_station=incoming_station if has_gap_or_overlap else None,
             has_increasing_station=False if self.reverse_direction else None,
         )
         tool.Alignment.create_object_for_referent(new_referent)

src/bonsai/bonsai/core/tool.py

@@ -1296,6 +1296,7 @@ class Alignment:
     def remove_layout_segment_objects(cls, h_layout): pass
     # Stationing
     def format_station(cls, station): pass
+    def parse_station(cls, text): pass
     # CSV import
     def create_alignment_from_csv(cls, filepath): pass
     def create_hierarchy_for_alignment(cls, alignment): pass

src/bonsai/bonsai/tool/alignment.py

@@ -898,6 +898,27 @@ class Alignment:
             return f"{float(station):.2f}"
         return ifcopenshell.util.alignment.station_as_string(ifc_file, float(station))
 
+    @classmethod
+    def parse_station(cls, text: str) -> float:
+        """Parse a station typed by the user into a float (project units).
+
+        Accepts either a plain number (``"1000"``) or stationing notation —
+        the inverse of format_station() — such as ``"10+00"`` (Imperial) or
+        ``"1+000"`` (SI); either notation is accepted regardless of the
+        project's own unit system. Falls back to a plain float parse when no
+        IFC file is open (e.g. dialog previews before a project exists).
+
+        Raises:
+            ValueError: If ``text`` is neither a plain number nor valid
+                stationing notation.
+        """
+        import ifcopenshell.util.alignment
+
+        ifc_file = tool.Ifc.get()
+        if ifc_file is None:
+            return float(text)
+        return ifcopenshell.util.alignment.station_from_string(ifc_file, text)
+
     @classmethod
     def _remove_blender_object(cls, obj: bpy.types.Object) -> bool:
         """Safely remove a Blender object and its data.

src/bonsai/test/tool/test_alignment.py

@@ -491,3 +491,45 @@ class TestFormatStation(NewFile):
 
     def test_without_project_falls_back_to_plain_number(self):
         assert subject.format_station(1234.5) == "1234.50"
+
+
+class TestParseStation(NewFile):
+    """tool.Alignment.parse_station — the inverse of format_station()."""
+
+    def _make_file(self, length):
+        import ifcopenshell.api.root
+        import ifcopenshell.api.unit
+
+        ifc = ifcopenshell.file(schema="IFC4X3_ADD2")
+        tool.Ifc.set(ifc)
+        ifcopenshell.api.root.create_entity(ifc, ifc_class="IfcProject")
+        ifcopenshell.api.unit.assign_unit(ifc, length=length)
+        return ifc
+
+    def test_plain_number_is_taken_literally(self):
+        self._make_file(length={"is_metric": True, "raw": "METERS"})
+        assert subject.parse_station("1000") == 1000.0
+        assert subject.parse_station("1000.5") == 1000.5
+
+    def test_metric_stationing_notation(self):
+        self._make_file(length={"is_metric": True, "raw": "METERS"})
+        assert subject.parse_station("10+050.000") == 10050.0
+        assert subject.parse_station("1+000") == 1000.0
+
+    def test_imperial_stationing_notation(self):
+        self._make_file(length={"is_metric": False, "raw": "FEET"})
+        assert subject.parse_station("100+50.00") == 10050.0
+        assert subject.parse_station("10+00") == 1000.0
+
+    def test_round_trips_with_format_station(self):
+        self._make_file(length={"is_metric": True, "raw": "METERS"})
+        for value in (0.0, 100.0, 10050.0, -50.0):
+            assert subject.parse_station(subject.format_station(value)) == pytest.approx(value, abs=0.01)
+
+    def test_without_project_falls_back_to_plain_float_parse(self):
+        assert subject.parse_station("1234.5") == 1234.5
+
+    def test_raises_on_invalid_input(self):
+        self._make_file(length={"is_metric": True, "raw": "METERS"})
+        with pytest.raises(ValueError):
+            subject.parse_station("not a station")

src/ifcopenshell-python/ifcopenshell/util/alignment.py

@@ -109,3 +109,57 @@ def station_as_string(file: ifcopenshell.file, sta: float):
         station_string = "-" + station_string
 
     return station_string
+
+
+def station_from_string(file: ifcopenshell.file, s: str) -> float:
+    """
+    Parses a station value typed by a user, in either of two forms:
+
+    - A plain real number, e.g. "1000" or "1000.5" -- taken literally as the
+      station value, in project units.
+    - Stationing notation "V1+V2", the inverse of :func:`station_as_string`,
+      e.g. "10+00" (a project with Imperial units) or "1+000" (a project
+      with SI units). V1 is worth 100 display-feet (Imperial) or 1000
+      display-metres (SI) -- matching station_as_string()'s plus-separator
+      placement -- and V2 is added to that, before converting the result
+      from the format's display unit (foot for Imperial, metre for SI) back
+      to the file's actual project length unit.
+
+    :param file: the IFC file, used to resolve the project's LENGTHUNIT
+    :param s: the station string to parse
+    :return: the station, in project units
+    :raises ValueError: if ``s`` is neither a plain number nor valid
+        stationing notation
+    """
+    s = s.strip()
+    if not s:
+        raise ValueError("Station value is empty")
+
+    if "+" not in s:
+        return float(s)
+
+    is_negative = s.startswith("-")
+    body = s[1:] if is_negative else s
+    left, separator, right = body.partition("+")
+    if not separator or not left.strip() or not right.strip():
+        raise ValueError(f"Invalid stationing notation: {s!r}")
+
+    v1 = float(left)
+    v2 = float(right)
+
+    unit_type = ifcopenshell.util.unit.get_project_unit(file, "LENGTHUNIT")
+    project_unit_to_metres = ifcopenshell.util.unit.calculate_unit_scale(file)
+    if unit_type is not None and unit_type.is_a("IfcConversionBasedUnit"):
+        # Imperial: display value is in feet, plus-separator is worth 100.
+        shifter = 100.0
+        metres_per_display_unit = 0.3048
+    else:
+        # SI: display value is in metres, plus-separator is worth 1000.
+        shifter = 1000.0
+        metres_per_display_unit = 1.0
+
+    display_value = v1 * shifter + v2
+    if is_negative:
+        display_value = -display_value
+
+    return display_value * metres_per_display_unit / project_unit_to_metres

src/ifcopenshell-python/test/util/test_alignment.py

@@ -152,3 +152,62 @@ def test_station_as_string():
     _test_si_stations_millimeter()
     _test_us_stations()
     _test_custom_named_conversion_based_unit_stations()
+
+
+def _si_file(unit_type="foot"):
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_si_unit(file, unit_type="LENGTHUNIT")  # meter
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    return file
+
+
+def _us_file():
+    file = ifcopenshell.file(schema="IFC4X3")
+    project = file.createIfcProject(GlobalId=ifcopenshell.guid.new(), Name="Test")
+    length = ifcopenshell.api.unit.add_conversion_based_unit(file, name="foot")
+    ifcopenshell.api.unit.assign_unit(file, units=[length])
+    return file
+
+
+def test_station_from_string_plain_number():
+    file = _si_file()
+    assert sta.station_from_string(file, "1000") == 1000.0
+    assert sta.station_from_string(file, "1000.5") == 1000.5
+    assert sta.station_from_string(file, "-50") == -50.0
+
+
+def test_station_from_string_si_notation():
+    file = _si_file()
+    assert sta.station_from_string(file, "1+000") == 1000.0
+    assert sta.station_from_string(file, "1+000.000") == 1000.0
+    assert sta.station_from_string(file, "0+100.000") == 100.0
+    assert sta.station_from_string(file, "-0+100.000") == -100.0
+    assert sta.station_from_string(file, "123+456.789") == pytest.approx(123456.789)
+
+
+def test_station_from_string_us_notation():
+    file = _us_file()
+    assert sta.station_from_string(file, "10+00") == pytest.approx(1000.0)
+    assert sta.station_from_string(file, "1+00.00") == pytest.approx(100.0)
+    assert sta.station_from_string(file, "-1+00.00") == pytest.approx(-100.0)
+    assert sta.station_from_string(file, "1234+56.79") == pytest.approx(123456.79, abs=0.01)
+
+
+def test_station_from_string_round_trips_with_station_as_string():
+    for file in (_si_file(), _us_file()):
+        for value in (0.0, 100.0, 1000.0, 123456.789, -123456.789):
+            s = sta.station_as_string(file, value)
+            assert sta.station_from_string(file, s) == pytest.approx(value, abs=0.01)
+
+
+def test_station_from_string_raises_on_invalid_input():
+    file = _si_file()
+    with pytest.raises(ValueError):
+        sta.station_from_string(file, "not a number")
+    with pytest.raises(ValueError):
+        sta.station_from_string(file, "1+")
+    with pytest.raises(ValueError):
+        sta.station_from_string(file, "+1")
+    with pytest.raises(ValueError):
+        sta.station_from_string(file, "")