Add .animate syntax

manimlib/animation/animation.py

@@ -1,6 +1,6 @@
 from copy import deepcopy
 
-from manimlib.mobject.mobject import Mobject
+from manimlib.mobject.mobject import Mobject, _AnimationBuilder
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.rate_functions import smooth
 from manimlib.utils.simple_functions import clip
@@ -159,3 +159,13 @@ class Animation(object):
 
     def is_remover(self):
         return self.remover
+
+
+def prepare_animation(anim):
+    if isinstance(anim, _AnimationBuilder):
+        return anim.build()
+
+    if isinstance(anim, Animation):
+        return anim
+
+    raise TypeError(f"Object {anim} cannot be converted to an animation")

manimlib/animation/composition.py

@@ -1,6 +1,6 @@
 import numpy as np
 
-from manimlib.animation.animation import Animation
+from manimlib.animation.animation import Animation, prepare_animation
 from manimlib.mobject.mobject import Group
 from manimlib.utils.bezier import integer_interpolate
 from manimlib.utils.bezier import interpolate
@@ -29,7 +29,7 @@ class AnimationGroup(Animation):
 
     def __init__(self, *animations, **kwargs):
         digest_config(self, kwargs)
-        self.animations = animations
+        self.animations = [prepare_animation(anim) for anim in animations]
         if self.group is None:
             self.group = Group(*remove_list_redundancies(
                 [anim.mobject for anim in animations]

manimlib/animation/transform.py

@@ -149,6 +149,12 @@ class MoveToTarget(Transform):
             )
 
 
+class _MethodAnimation(MoveToTarget):
+    def __init__(self, mobject, methods):
+        self.methods = methods
+        super().__init__(mobject)
+
+
 class ApplyMethod(Transform):
     def __init__(self, method, *args, **kwargs):
         """

manimlib/mobject/mobject.py

@@ -80,6 +80,11 @@ class Mobject(object):
         if self.depth_test:
             self.apply_depth_test()
 
+    @property
+    def animate(self):
+        # Borrowed from https://github.com/ManimCommunity/manim/
+        return _AnimationBuilder(self)
+
     def __str__(self):
         return self.__class__.__name__
 
@@ -1571,3 +1576,51 @@ class Point(Mobject):
 
     def set_location(self, new_loc):
         self.set_points(np.array(new_loc, ndmin=2, dtype=float))
+
+
+class _AnimationBuilder:
+    def __init__(self, mobject):
+        self.mobject = mobject
+        self.overridden_animation = None
+        self.mobject.generate_target()
+        self.is_chaining = False
+        self.methods = []
+
+    def __getattr__(self, method_name):
+        method = getattr(self.mobject.target, method_name)
+        self.methods.append(method)
+        has_overridden_animation = hasattr(method, "_override_animate")
+
+        if (self.is_chaining and has_overridden_animation) or self.overridden_animation:
+            raise NotImplementedError(
+                "Method chaining is currently not supported for "
+                "overridden animations"
+            )
+
+        def update_target(*method_args, **method_kwargs):
+            if has_overridden_animation:
+                self.overridden_animation = method._override_animate(
+                    self.mobject, *method_args, **method_kwargs
+                )
+            else:
+                method(*method_args, **method_kwargs)
+            return self
+
+        self.is_chaining = True
+        return update_target
+
+    def build(self):
+        from manimlib.animation.transform import _MethodAnimation
+
+        if self.overridden_animation:
+            return self.overridden_animation
+
+        return _MethodAnimation(self.mobject, self.methods)
+
+
+def override_animate(method):
+    def decorator(animation_method):
+        method._override_animate = animation_method
+        return animation_method
+
+    return decorator

manimlib/scene/scene.py

@@ -10,7 +10,7 @@ import numpy as np
 import time
 from IPython.terminal.embed import InteractiveShellEmbed
 
-from manimlib.animation.animation import Animation
+from manimlib.animation.animation import prepare_animation
 from manimlib.animation.transform import MoveToTarget
 from manimlib.mobject.mobject import Point
 from manimlib.camera.camera import Camera
@@ -348,10 +348,7 @@ class Scene(object):
             state["method_args"] = []
 
         for arg in args:
-            if isinstance(arg, Animation):
+            if inspect.ismethod(arg):
-                compile_method(state)
-                animations.append(arg)
-            elif inspect.ismethod(arg):
                 compile_method(state)
                 state["curr_method"] = arg
             elif state["curr_method"] is not None:
@@ -362,7 +359,13 @@ class Scene(object):
                     you meant to pass in as a Scene.play argument
                 """)
             else:
-                raise Exception("Invalid play arguments")
+                try:
+                    anim = prepare_animation(arg)
+                except TypeError:
+                    raise TypeError(f"Unexpected argument {arg} passed to Scene.play()")
+
+                compile_method(state)
+                animations.append(anim)
         compile_method(state)
 
         for animation in animations: