Call .finish() for every animation in AnimationGroup on finish (#3951)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Francisco Manríquez Novoa <[email protected]>
Co-authored-by: JasonGrace2282 <[email protected]>
Co-authored-by: Aarush Deshpande <[email protected]>

Author: 4 people

manim/animation/composition.py

@@ -98,7 +98,8 @@ def _setup_scene(self, scene) -> None:
             anim._setup_scene(scene)
 
     def finish(self) -> None:
-        self.interpolate(1)
+        for anim in self.animations:
+            anim.finish()
         self.anims_begun[:] = True
         self.anims_finished[:] = True
         if self.suspend_mobject_updating:

tests/module/animation/test_composition.py

@@ -171,6 +171,24 @@ def test_animationgroup_is_passing_remover_to_nested_animationgroups():
     assert polygon_animation.remover
 
 
+def test_animationgroup_calls_finish():
+    class MyAnimation(Animation):
+        def __init__(self, mobject):
+            super().__init__(mobject)
+            self.finished = False
+
+        def finish(self):
+            self.finished = True
+
+    scene = Scene()
+    sqr_animation = MyAnimation(Square())
+    circ_animation = MyAnimation(Circle())
+    animation_group = AnimationGroup(sqr_animation, circ_animation)
+    scene.play(animation_group)
+    assert sqr_animation.finished
+    assert circ_animation.finished
+
+
 def test_empty_animation_group_fails():
     with pytest.raises(ValueError, match="Please add at least one subanimation."):
         AnimationGroup().begin()