Implement abstract members.

Lib/fontParts/base/base.py

@@ -189,7 +189,7 @@ def interpolate(
 # ------------
 
 
-class BaseObject:
+class BaseObject(Generic[BaseObjectType]):
     r"""Provide common base functionality to objects.
 
     This class is intended to serve as a foundation for other classes, supplying
@@ -1399,13 +1399,13 @@ def _set_selected(self, value: bool) -> None:
     # Sub-Objects
     # -----------
     @classmethod
-    def _getSelectedSubObjects(cls, subObjects: CollectionType[Any]) -> Tuple[Any]:
+    def _getSelectedSubObjects(cls, subObjects: Any) -> Tuple[Any]:
         selected = tuple(obj for obj in subObjects if obj.selected)
         return selected
 
     @classmethod
     def _setSelectedSubObjects(
-        cls, subObjects: CollectionType[Any], selected: CollectionType[Any]
+        cls, subObjects: Any, selected: Any
     ) -> None:
         for obj in subObjects:
             obj.selected = obj in selected

Lib/fontParts/base/contour.py

@@ -1,5 +1,5 @@
 from __future__ import annotations
-from typing import TYPE_CHECKING, cast, Any, Iterator, List, Optional, Tuple, Union
+from typing import (TYPE_CHECKING, cast, Any, Iterator, List, Optional, Tuple, TypeVar, Union)
 
 from fontParts.base.errors import FontPartsError
 from fontParts.base.base import (
@@ -32,6 +32,7 @@
     from fontParts.base.layer import BaseLayer
     from fontParts.base.font import BaseFont
 
+BaseContourType = TypeVar("BaseContourType", bound="BaseContour")
 PointCollectionType = CollectionType[PairCollectionType[IntFloatType]]
 
 
@@ -65,7 +66,7 @@ def _reprContents(self) -> List[str]:
             contents += self.glyph._reprContents()
         return contents
 
-    def copyData(self, source: BaseContour) -> None:
+    def copyData(self, source: BaseContourType) -> None:
         """Copy data from another contour instance.
 
         This will copy the contents of the following attributes from `source`

Lib/fontParts/base/font.py

@@ -204,7 +204,7 @@ def _get_base_path(self) -> Optional[str]:
             path = normalizers.normalizeFilePath(path)
         return path
 
-    def _get_path(self, **kwargs: Any) -> Optional[str]:
+    def _get_path(self, **kwargs: Any) -> Optional[str]:  # type: ignore[return]
         r"""Get the path to the native font file.
 
         This method is the environment implementation
@@ -574,7 +574,7 @@ def _get_base_info(self) -> BaseInfo:
         info.font = self
         return info
 
-    def _get_info(self) -> BaseInfo:
+    def _get_info(self) -> BaseInfo:  # type: ignore[return]
         """Get the native font's info object.
 
         This is the environment implementation of :attr:`BaseFont.info`.
@@ -613,7 +613,7 @@ def _get_base_groups(self) -> BaseGroups:
         groups.font = self
         return groups
 
-    def _get_groups(self) -> BaseGroups:
+    def _get_groups(self) -> BaseGroups:  # type: ignore[return]
         """Get the native font's groups object.
 
         This is the environment implementation
@@ -653,7 +653,7 @@ def _get_base_kerning(self) -> BaseKerning:
         kerning.font = self
         return kerning
 
-    def _get_kerning(self) -> BaseKerning:
+    def _get_kerning(self) -> BaseKerning:  # type: ignore[return]
         """Get the native font's kerning object.
 
         This is the environment implementation
@@ -752,7 +752,7 @@ def _get_base_features(self) -> BaseFeatures:
         features.font = self
         return features
 
-    def _get_features(self) -> BaseFeatures:
+    def _get_features(self) -> BaseFeatures:  # type: ignore[return]
         """Get the native font's features object.
 
         This is the environment implementation of
@@ -792,7 +792,7 @@ def _get_base_lib(self) -> BaseLib:
         lib.font = self
         return lib
 
-    def _get_lib(self) -> BaseLib:
+    def _get_lib(self) -> BaseLib:  # type: ignore[return]
         """Get the native font's lib object.
 
         This is the environment implementation of :attr:`BaseFont.lib`.
@@ -837,7 +837,7 @@ def _get_base_tempLib(self) -> BaseLib:
         lib.font = self
         return lib
 
-    def _get_tempLib(self) -> BaseLib:
+    def _get_tempLib(self) -> BaseLib:  # type: ignore[return]
         """Get the native font's temporary lib object.
 
         This is the environment implementation
@@ -883,7 +883,7 @@ def _get_base_layers(self) -> Tuple[BaseLayer, ...]:
             self._setFontInLayer(layer)
         return tuple(layers)
 
-    def _get_layers(self, **kwargs: Any) -> Tuple[BaseLayer, ...]:
+    def _get_layers(self, **kwargs: Any) -> Tuple[BaseLayer, ...]:  # type: ignore[return]
         r"""Get the native font's layer objects.
 
         This is the environment implementation of
@@ -932,7 +932,7 @@ def _set_base_layerOrder(self, value: CollectionType[str]) -> None:
         value = normalizers.normalizeLayerOrder(value, self)
         self._set_layerOrder(value)
 
-    def _get_layerOrder(self, **kwargs: Any) -> Tuple[str, ...]:
+    def _get_layerOrder(self, **kwargs: Any) -> Tuple[str, ...]:  # type: ignore[return]
         r"""Get the order of the layers in the native font.
 
         This is the environment implementation of the
@@ -1006,7 +1006,7 @@ def _set_base_defaultLayerName(self, value: str) -> None:
         value = normalizers.normalizeDefaultLayerName(value, self)
         self._set_defaultLayerName(value)
 
-    def _get_defaultLayerName(self) -> str:
+    def _get_defaultLayerName(self) -> str:  # type: ignore[return]
         """Get the name of the native font's default layer.
 
         This is the environment implementation of
@@ -1181,7 +1181,7 @@ def newLayer(
         self._setFontInLayer(layer)
         return layer
 
-    def _newLayer(
+    def _newLayer(  # type: ignore[return]
         self,
         name: str,
         color: Optional[QuadrupleCollectionType[IntFloatType]],
@@ -1577,7 +1577,7 @@ def _set_base_glyphOrder(self, value: CollectionType[str]) -> None:
         value = normalizers.normalizeGlyphOrder(value)
         self._set_glyphOrder(value)
 
-    def _get_glyphOrder(self) -> Tuple[str, ...]:
+    def _get_glyphOrder(self) -> Tuple[str, ...]:  # type: ignore[return]
         r"""Get the order of the glyphs in the native font.
 
         This is the environment implementation of the
@@ -1732,7 +1732,7 @@ def _get_guidelines(self) -> Tuple[BaseGuideline, ...]:
     def _len__guidelines(self) -> int:
         return self._lenGuidelines()
 
-    def _lenGuidelines(self, **kwargs: Any) -> int:
+    def _lenGuidelines(self, **kwargs: Any) -> int:  # type: ignore[return]
         r"""Return the number of font-level guidelines in the native font.
 
         :param \**kwargs: Additional keyword arguments.
@@ -1754,7 +1754,7 @@ def _getitem__guidelines(self, index: int) -> BaseGuideline:
         self._setFontInGuideline(guideline)
         return guideline
 
-    def _getGuideline(self, index: int, **kwargs: Any) -> BaseGuideline:
+    def _getGuideline(self, index: int, **kwargs: Any) -> BaseGuideline:  # type: ignore[return]
         r"""Return the guideline at the given index.
 
         :param index: The index of the guideline.
@@ -1846,7 +1846,7 @@ def appendGuideline(
         newGuideline.font = self
         return newGuideline
 
-    def _appendGuideline(
+    def _appendGuideline(  # type: ignore[return]
         self,
         position: Optional[PairCollectionType[IntFloatType]],
         angle: Optional[float],

Lib/fontParts/base/layer.py

@@ -1,6 +1,7 @@
 # pylint: disable=C0103, C0302, C0114, W0613
 from __future__ import annotations
-from typing import TYPE_CHECKING, Any, Callable, Iterator, List, Optional, Tuple
+from abc import ABC, abstractmethod
+from typing import TYPE_CHECKING, Any, Callable, Iterator, List, NoReturn, Optional, Tuple, TypeVar
 import collections
 
 from fontParts.base.base import (
@@ -29,7 +30,7 @@
     from fontParts.base.lib import BaseLib
 
 
-class _BaseGlyphVendor(BaseObject, SelectionMixin):
+class _BaseGlyphVendor(BaseObject, SelectionMixin, ABC):
     """Provide common glyph interaction.
 
     This class provides common glyph interaction code to the
@@ -573,6 +574,28 @@ def _set_selectedGlyphNames(self, value: CollectionType[str]) -> None:
 
     has_key: Callable[[_BaseGlyphVendor, str], bool] = __contains__
 
+    # ----------------
+    # Abstract Members
+    # ----------------
+
+    defaultLayer: dynamicProperty = dynamicProperty("base_defaultLayer")
+
+    @abstractmethod
+    def _get_base_defaultLayer(self) -> BaseLayer:
+        pass
+
+    @abstractmethod
+    def _set_base_defaultLayer(self, layer: BaseLayer) -> None:
+        pass
+
+    @abstractmethod
+    def _get_defaultLayer(self) -> BaseLayer:
+        pass
+
+    @abstractmethod
+    def _set_defaultLayer(self, value: BaseLayer) -> None:
+        pass
+
 
 class BaseLayer(_BaseGlyphVendor, InterpolationMixin, DeprecatedLayer, RemovedLayer):
     """Represent the basis for a layer object.
@@ -1224,3 +1247,21 @@ def _getCharacterMapping(self) -> CharacterMappingType:
             for code in glyph.unicodes:
                 mapping[code].append(glyph.name)
         return {k: tuple(v) for k, v in mapping.items()}
+
+    # --------------------------
+    # Abstract Members Overrides
+    # --------------------------
+
+    defaultLayer: dynamicProperty = dynamicProperty("base_defaultLayer")
+
+    def _get_base_defaultLayer(self) -> BaseLayer:
+        raise NotImplementedError("BaseLayer does not implement this method.")
+
+    def _set_base_defaultLayer(self, layer: BaseLayer) -> None:
+        raise NotImplementedError("BaseLayer does not implement this method.")
+
+    def _get_defaultLayer(self) -> BaseLayer:
+        raise NotImplementedError("BaseLayer does not implement this method.")
+
+    def _set_defaultLayer(self, value: BaseLayer) -> None:
+        raise NotImplementedError("BaseLayer does not implement this method.")