Mypy type correctness (#3199)

1 files changed, 9 insertions, 7 deletions

diff --git a/lib/elements/element.py b/lib/elements/element.py
index ea2d5d6b..6f2c52e9 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -2,6 +2,7 @@
 #
 # Copyright (c) 2010 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+from __future__ import annotations
 import json
 import sys
 from contextlib import contextmanager
@@ -79,8 +80,9 @@ class EmbroideryElement(object):
             prop = getattr(cls, attr)
             if isinstance(prop, property):
                 # The 'param' attribute is set by the 'param' decorator defined above.
-                if hasattr(prop.fget, 'param'):
-                    params.append(prop.fget.param)
+                fget = prop.fget
+                if fget is not None and hasattr(fget, 'param'):
+                    params.append(fget.param)
         return params
 
     @cache
@@ -215,18 +217,18 @@ class EmbroideryElement(object):
 
         # First, figure out the translation component of the transform.  Using a zero
         # vector completely cancels out the rotation, scale, and skew components.
-        zero = [0, 0]
+        zero = (0, 0)
         zero = inkex.Transform.apply_to_point(node_transform, zero)
         translate = Point(*zero)
 
         # Next, see how the transform affects unit vectors in the X and Y axes.  We
         # need to subtract off the translation or it will affect the magnitude of
         # the resulting vector, which we don't want.
-        unit_x = [1, 0]
+        unit_x = (1, 0)
         unit_x = inkex.Transform.apply_to_point(node_transform, unit_x)
         sx = (Point(*unit_x) - translate).length()
 
-        unit_y = [0, 1]
+        unit_y = (0, 1)
         unit_y = inkex.Transform.apply_to_point(node_transform, unit_y)
         sy = (Point(*unit_y) - translate).length()
 
@@ -455,7 +457,7 @@ class EmbroideryElement(object):
         raise NotImplementedError("INTERNAL ERROR: %s must implement shape()", self.__class__)
 
     @property
-    def first_stitch(self):
+    def first_stitch(self) -> Optional[ShapelyPoint]:
         # first stitch is an approximation to where the first stitch may possibly be
         # if not defined through commands or repositioned by the previous element
         raise NotImplementedError("INTERNAL ERROR: %s must implement first_stitch()", self.__class__)
@@ -521,7 +523,7 @@ class EmbroideryElement(object):
 
         return lock_start, lock_end
 
-    def to_stitch_groups(self, last_stitch_group: Optional[StitchGroup], next_element: Optional[ShapelyPoint] = None) -> List[StitchGroup]:
+    def to_stitch_groups(self, last_stitch_group: Optional[StitchGroup], next_element: Optional[EmbroideryElement] = None) -> List[StitchGroup]:
         raise NotImplementedError("%s must implement to_stitch_groups()" % self.__class__.__name__)
 
     @debug.time