Fix fillet preview crash + surface openings on fillet walls

Three wall-gizmo fixes:

* GizmoWallFilletPreview crashed on every draw_prepare after the
  DRY-colors refactor moved decoration lookups onto
  self.get_decoration_colors() — that method lives on
  BillboardingGizmoGroupMixin / BaseParametricGizmoGroup, but
  GizmoWallFilletPreview inherited only from bpy.types.GizmoGroup.
  setup() AttributeError'd silently, leaving radius_dim and friends
  unset. Add the mixin to the bases; rename _position_gizmos to
  position_gizmos so the mixin's refresh/draw_prepare dispatch lands
  correctly and drop the now-redundant overrides.

* GizmoWallAddOpening's poll gated on the strict is_wall predicate,
  which rejects fillet-corner walls (no LAYER2 usage by IFC spec).
  Switch to is_path_connectable_wall on both the active and the
  partner-exclusion checks so the add-opening icon surfaces over
  curved corners — matching every other wall-state gizmo's host gate.

* Show / hide openings was only available on LAYER2 walls because
  GizmoWallEdition's parametric edit pipeline (which carries the
  toggle) refuses fillet bodies. Add GizmoWallFilletToggleOpenings,
  a dedicated single-icon group that polls on is_fillet_corner_wall
  and reuses bim.toggle_wall_openings — the body stays untouched.

Forward-compat AST guards in test_wall_gizmos_forward_compat.py pin
both invariants: every wall GizmoGroup that calls
self.get_decoration_colors() must inherit a mixin that provides it,
and GizmoWallAddOpening.poll must keep using the looser predicate.

Generated with the assistance of an AI coding tool.

src/bonsai/bonsai/bim/module/model/__init__.py

@@ -104,6 +104,7 @@ classes = (
     wall.GizmoWallExtendVertically,
     wall.GizmoWallFilletPreview,
     wall.GizmoWallFilletReedit,
+    wall.GizmoWallFilletToggleOpenings,
     wall.GizmoWallJoinIntersection,
     wall.GizmoWallLinkToggle,
     wall.GizmoWallUnjoinSingle,

src/bonsai/bonsai/bim/module/model/wall.py

@@ -3273,12 +3273,12 @@ class GizmoWallAddOpening(bpy.types.GizmoGroup, _WallGeomCachedBillboardingMixin
         if active is None or active not in selected:
             return False
         element = tool.Ifc.get_entity(active)
-        if not element or not tool.Blender.Modifier.is_wall(element):
+        if not element or not tool.Parametric.is_path_connectable_wall(element):
             return False
         other = next(o for o in selected if o is not active)
         # If the other object is also a wall, the wall-join gizmo handles it instead.
         other_element = tool.Ifc.get_entity(other)
-        if other_element and tool.Blender.Modifier.is_wall(other_element):
+        if other_element and tool.Parametric.is_path_connectable_wall(other_element):
             return False
         return True
 
@@ -3685,7 +3685,7 @@ class GizmoWallUnjoinSingle(bpy.types.GizmoGroup, _WallGeomCachedBillboardingMix
             icon.partner_obj = other_obj
 
 
-class GizmoWallFilletPreview(bpy.types.GizmoGroup):
+class GizmoWallFilletPreview(bpy.types.GizmoGroup, gizmo.BillboardingGizmoGroupMixin):
     """Gizmo group for the wall-fillet preview: radius dimension widget +
     trim-length dimension widget + validate / cancel icons.
 
@@ -3731,7 +3731,7 @@ class GizmoWallFilletPreview(bpy.types.GizmoGroup):
         gz.move_get_cb = preview_base.make_dim_getter(_props_callback, "radius")
         gz.move_set_cb = preview_base.make_dim_setter(_props_callback, "radius")
         # Set `axis` only (NOT `local_axis`) so `get_axis_direction` falls
-        # through to the world-space direction we set in `_position_gizmos`.
+        # through to the world-space direction set per frame on each gizmo.
         # The preview spans world space independent of either wall's local
         # frame, so the active-object transform that `local_axis` would go
         # through is the wrong frame.
@@ -3756,10 +3756,9 @@ class GizmoWallFilletPreview(bpy.types.GizmoGroup):
         self.radius_dim = gz
 
         # Sweep angle is geometrically invariant during drag (depends only on
-        # the angle between the two walls). Cached here per-frame from
-        # `_position_gizmos` so the trim getter / setter can convert
-        # trim_length ↔ radius via `tan(sweep/2)` without re-running the full
-        # geometry pipeline on every drag tick.
+        # the angle between the two walls). Cached per frame so the trim
+        # getter / setter can convert trim_length ↔ radius via tan(sweep/2)
+        # without re-running the full geometry pipeline on every drag tick.
         self._sweep_angle = math.pi / 2
 
         # Trim-length widget expresses the SAME single DOF as the radius
@@ -3839,13 +3838,7 @@ class GizmoWallFilletPreview(bpy.types.GizmoGroup):
 
         return _set
 
-    def refresh(self, context: bpy.types.Context) -> None:
-        self._position_gizmos(context)
-
-    def draw_prepare(self, context: bpy.types.Context) -> None:
-        self._position_gizmos(context)
-
-    def _position_gizmos(self, context: bpy.types.Context) -> None:
+    def position_gizmos(self, context: bpy.types.Context) -> None:
         wall_a_obj, wall_b_obj = _wall_fillet_preview_walls(context)
         if wall_a_obj is None or wall_b_obj is None:
             for gz in (self.radius_dim, self.trim_dim, self.validate_icon, self.cancel_icon):
@@ -4016,6 +4009,69 @@ class GizmoWallFilletReedit(bpy.types.GizmoGroup, _WallGeomCachedBillboardingMix
         self.edit_icon.hide = False
 
 
+class GizmoWallFilletToggleOpenings(bpy.types.GizmoGroup, _WallGeomCachedBillboardingMixin):
+    """Surfaces the show / hide openings icon on a fillet-corner wall.
+
+    GizmoWallEdition's idle row already exposes this toggle for LAYER2 walls,
+    but its poll routes through the parametric edit pipeline which by IFC
+    spec rejects fillet corners (their banana body is hand-built and would be
+    flattened by the parametric regen). The openings toggle itself is a
+    viewport-state action independent of the body, so a parallel poll keeps
+    it available without re-opening the parametric edits."""
+
+    bl_idname = "OBJECT_GGT_bim_wall_fillet_toggle_openings"
+    bl_label = "Fillet Wall Toggle Openings Gizmo"
+    bl_space_type = "VIEW_3D"
+    bl_region_type = "WINDOW"
+    bl_options = {"3D", "PERSISTENT"}
+
+    ICON_TOP_LIFT: ClassVar[float] = 0.15
+    # Screen-space X offset from the pen icon so the two stack horizontally
+    # rather than overlap at the chord midpoint.
+    ICON_OFFSET_X: ClassVar[float] = 0.4
+
+    @classmethod
+    def poll(cls, context: bpy.types.Context) -> bool:
+        if not _wall_gizmo_poll_gate(context):
+            return False
+        active = tool.Blender.get_active_object(is_selected=True)
+        if active is None:
+            return False
+        if len(list(tool.Blender.get_selected_objects())) != 1:
+            return False
+        element = tool.Ifc.get_entity(active)
+        if element is None or not element.is_a("IfcWall"):
+            return False
+        return tool.Parametric.is_fillet_corner_wall(element)
+
+    def setup(self, context: bpy.types.Context) -> None:
+        default_color, highlight_color = self.get_decoration_colors()
+        self.toggle_openings_icon = self.setup_icon_gizmo(
+            "VIEW3D_GT_add_opening",
+            default_color,
+            highlight_color,
+            "bim.toggle_wall_openings",
+        )
+
+    def position_gizmos(self, context: bpy.types.Context) -> None:
+        selected = list(tool.Blender.get_selected_objects())
+        if len(selected) != 1:
+            self.toggle_openings_icon.hide = True
+            return
+        corner_obj = selected[0]
+        geom = _get_wall_geom_cached(self, corner_obj)
+        if geom is None:
+            self.toggle_openings_icon.hide = True
+            return
+        billboard_rot = gizmo.get_billboard_rotation(context)
+        origin = corner_obj.matrix_world.translation
+        top_z = origin.z + (geom.get("height") or 3.0) + self.ICON_TOP_LIFT
+        anchor = Vector((origin.x, origin.y, top_z))
+        offset_x = billboard_rot @ Vector((self.ICON_OFFSET_X, 0.0, 0.0))
+        self.toggle_openings_icon.matrix_basis = gizmo.billboarded_at(anchor + offset_x, billboard_rot)
+        self.toggle_openings_icon.hide = False
+
+
 class JoinWallsIntersection(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.join_walls_intersection"
     bl_label = "Join Walls at Corner"

src/bonsai/test/bim/module/model/test_wall_gizmos_forward_compat.py

@@ -41,7 +41,7 @@ def test_iter_path_connections_uses_path_connectable_predicate():
     poll. Strict ``is_wall`` rejects fillet-corner walls (which have no
     LAYER2 usage by IFC spec), so a regression to ``is_wall`` would silently
     drop fillet partners from the connection list — visible to the user as
-    "the corner looks unconnected from the adjacent wall's selection.\""""
+    "the corner looks unconnected from the adjacent wall's selection.\" """
     from bonsai.bim.module.model.wall import _iter_path_connections
 
     source = inspect.getsource(_iter_path_connections)
@@ -90,3 +90,72 @@ def test_gizmo_wall_link_toggle_invokes_partner_bbox_helper():
         "trigger for this feature; replacing it with an ad-hoc draw call would "
         "drift from the array-children bbox styling."
     )
+
+
+def test_every_wall_gizmo_group_resolves_get_decoration_colors():
+    """Any wall ``GizmoGroup`` whose ``setup()`` reads decoration colours via
+    ``self.get_decoration_colors()`` must inherit from a mixin that supplies
+    it (``gizmo.BaseParametricGizmoGroup`` or ``gizmo.BillboardingGizmoGroupMixin``).
+    Without the mixin the call AttributeErrors inside ``setup()``, Blender
+    logs the failure and skips the rest of ``setup()``, and every later
+    ``draw_prepare()`` blows up on whichever attribute the truncated setup
+    failed to assign — a silent, runtime-only regression that no other test
+    catches."""
+    import bpy
+
+    from bonsai.bim.module.model import wall as wall_module
+
+    offenders: list[str] = []
+    for name in dir(wall_module):
+        cls = getattr(wall_module, name)
+        if not inspect.isclass(cls):
+            continue
+        if inspect.getmodule(cls) is not wall_module:
+            continue
+        if not issubclass(cls, bpy.types.GizmoGroup):
+            continue
+        setup = cls.__dict__.get("setup")
+        if setup is None:
+            continue
+        try:
+            src = inspect.getsource(setup)
+        except (OSError, TypeError):
+            continue
+        if "self.get_decoration_colors()" not in src:
+            continue
+        if not hasattr(cls, "get_decoration_colors"):
+            offenders.append(cls.__name__)
+
+    assert not offenders, (
+        f"GizmoGroup subclasses {offenders} call self.get_decoration_colors() in "
+        "setup() but inherit from no class that provides it. Add "
+        "gizmo.BillboardingGizmoGroupMixin (or gizmo.BaseParametricGizmoGroup) to "
+        "the class bases — both define get_decoration_colors and are the canonical "
+        "wall-gizmo mixins."
+    )
+
+
+def test_gizmo_wall_add_opening_accepts_fillet_corner_active():
+    """``GizmoWallAddOpening.poll`` must gate on ``is_path_connectable_wall``,
+    not the strict ``is_wall`` predicate. Fillet-corner walls carry no LAYER2
+    usage by IFC spec, so the strict predicate rejects them and the
+    add-opening icon never surfaces over a curved corner — symmetry with the
+    join / unjoin / extend wall gizmos (all of which already poll on the
+    looser predicate) is required for the user to drop openings into fillet
+    corners at all."""
+    from bonsai.bim.module.model.wall import GizmoWallAddOpening
+
+    source = textwrap.dedent(inspect.getsource(GizmoWallAddOpening.poll))
+    tree = ast.parse(source)
+    attr_names = {node.attr for node in ast.walk(tree) if isinstance(node, ast.Attribute)}
+
+    assert "is_path_connectable_wall" in attr_names, (
+        "GizmoWallAddOpening.poll must gate on tool.Parametric.is_path_connectable_wall "
+        "for both the active element and the partner-exclusion check. The strict "
+        "is_wall predicate hides the add-opening gizmo over every fillet-corner wall."
+    )
+    assert "is_wall" not in attr_names, (
+        "GizmoWallAddOpening.poll must NOT call .is_wall — that strict predicate "
+        "drops fillet-corner walls. Use is_path_connectable_wall instead, matching "
+        "the host gate every other wall-state gizmo group uses."
+    )