chore: add type hints to manimlib.mobject

manimlib/mobject/boolean_ops.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import numpy as np
 import pathops
 
@@ -7,7 +9,7 @@
 # Boolean operations between 2D mobjects
 # Borrowed from from https://github.com/ManimCommunity/manim/
 
-def _convert_vmobject_to_skia_path(vmobject):
+def _convert_vmobject_to_skia_path(vmobject: VMobject) -> pathops.Path:
     path = pathops.Path()
     subpaths = vmobject.get_subpaths_from_points(vmobject.get_all_points())
     for subpath in subpaths:
@@ -21,7 +23,10 @@ def _convert_vmobject_to_skia_path(vmobject):
     return path
 
 
-def _convert_skia_path_to_vmobject(path, vmobject):
+def _convert_skia_path_to_vmobject(
+    path: pathops.Path,
+    vmobject: VMobject
+) -> VMobject:
     PathVerb = pathops.PathVerb
     current_path_start = np.array([0.0, 0.0, 0.0])
     for path_verb, points in path:
@@ -45,7 +50,7 @@ def _convert_skia_path_to_vmobject(path, vmobject):
 
 
 class Union(VMobject):
-    def __init__(self, *vmobjects, **kwargs):
+    def __init__(self, *vmobjects: VMobject, **kwargs):
         if len(vmobjects) < 2:
             raise ValueError("At least 2 mobjects needed for Union.")
         super().__init__(**kwargs)
@@ -59,7 +64,7 @@ def __init__(self, *vmobjects, **kwargs):
 
 
 class Difference(VMobject):
-    def __init__(self, subject, clip, **kwargs):
+    def __init__(self, subject: VMobject, clip: VMobject, **kwargs):
         super().__init__(**kwargs)
         outpen = pathops.Path()
         pathops.difference(
@@ -71,7 +76,7 @@ def __init__(self, subject, clip, **kwargs):
 
 
 class Intersection(VMobject):
-    def __init__(self, *vmobjects, **kwargs):
+    def __init__(self, *vmobjects: VMobject, **kwargs):
         if len(vmobjects) < 2:
             raise ValueError("At least 2 mobjects needed for Intersection.")
         super().__init__(**kwargs)
@@ -94,7 +99,7 @@ def __init__(self, *vmobjects, **kwargs):
 
 
 class Exclusion(VMobject):
-    def __init__(self, *vmobjects, **kwargs):
+    def __init__(self, *vmobjects: VMobject, **kwargs):
         if len(vmobjects) < 2:
             raise ValueError("At least 2 mobjects needed for Exclusion.")
         super().__init__(**kwargs)

manimlib/mobject/changing.py

@@ -1,4 +1,9 @@
+from __future__ import annotations
+
+from typing import Callable
+
 import numpy as np
+
 from manimlib.constants import BLUE_D
 from manimlib.constants import BLUE_B
 from manimlib.constants import BLUE_E
@@ -20,23 +25,23 @@ class AnimatedBoundary(VGroup):
         "fade_rate_func": smooth,
     }
 
-    def __init__(self, vmobject, **kwargs):
+    def __init__(self, vmobject: VMobject, **kwargs):
         super().__init__(**kwargs)
-        self.vmobject = vmobject
-        self.boundary_copies = [
+        self.vmobject: VMobject = vmobject
+        self.boundary_copies: list[VMobject] = [
             vmobject.copy().set_style(
                 stroke_width=0,
                 fill_opacity=0
             )
             for x in range(2)
         ]
         self.add(*self.boundary_copies)
-        self.total_time = 0
+        self.total_time: float = 0
         self.add_updater(
             lambda m, dt: self.update_boundary_copies(dt)
         )
 
-    def update_boundary_copies(self, dt):
+    def update_boundary_copies(self, dt: float) -> None:
         # Not actual time, but something which passes at
         # an altered rate to make the implementation below
         # cleaner
@@ -67,7 +72,13 @@ def update_boundary_copies(self, dt):
 
         self.total_time += dt
 
-    def full_family_become_partial(self, mob1, mob2, a, b):
+    def full_family_become_partial(
+        self,
+        mob1: VMobject,
+        mob2: VMobject,
+        a: float,
+        b: float
+    ):
         family1 = mob1.family_members_with_points()
         family2 = mob2.family_members_with_points()
         for sm1, sm2 in zip(family1, family2):
@@ -84,14 +95,14 @@ class TracedPath(VMobject):
         "time_per_anchor": 1 / 15,
     }
 
-    def __init__(self, traced_point_func, **kwargs):
+    def __init__(self, traced_point_func: Callable[[], np.ndarray], **kwargs):
         super().__init__(**kwargs)
         self.traced_point_func = traced_point_func
-        self.time = 0
-        self.traced_points = []
+        self.time: float = 0
+        self.traced_points: list[np.ndarray] = []
         self.add_updater(lambda m, dt: m.update_path(dt))
 
-    def update_path(self, dt):
+    def update_path(self, dt: float):
         if dt == 0:
             return self
         point = self.traced_point_func().copy()
@@ -133,7 +144,11 @@ class TracingTail(TracedPath):
         "time_traced": 1.0,
     }
 
-    def __init__(self, mobject_or_func, **kwargs):
+    def __init__(
+        self,
+        mobject_or_func: Mobject | Callable[[], np.ndarray],
+        **kwargs
+    ):
         if isinstance(mobject_or_func, Mobject):
             func = mobject_or_func.get_center
         else: