VGroup can now be initialized with VMobject iterables

manim/mobject/types/vectorized_mobject.py

@@ -24,6 +24,7 @@
 from manim.constants import *
 from manim.mobject.mobject import Mobject
 from manim.mobject.opengl.opengl_compatibility import ConvertToOpenGL
+from manim.mobject.opengl.opengl_mobject import OpenGLMobject
 from manim.mobject.opengl.opengl_vectorized_mobject import OpenGLVMobject
 from manim.mobject.three_d.three_d_utils import (
     get_3d_vmob_gradient_start_and_end_points,
@@ -47,6 +48,8 @@
 from manim.utils.space_ops import rotate_vector, shoelace_direction
 
 if TYPE_CHECKING:
+    from types import GeneratorType
+
     import numpy.typing as npt
     from typing_extensions import Self
 
@@ -2056,7 +2059,11 @@
 
     """
 
-    def __init__(self, *vmobjects, **kwargs):
+    def __init__(
+        self,
+        *vmobjects: VMobject | Iterable[VMobject] | GeneratorType[VMobject],
+        **kwargs,
+    ):
         super().__init__(**kwargs)
         self.add(*vmobjects)
 
@@ -2069,13 +2076,16 @@
             f"submobject{'s' if len(self.submobjects) > 0 else ''}"
         )
 
-    def add(self, *vmobjects: VMobject) -> Self:
-        """Checks if all passed elements are an instance of VMobject and then add them to submobjects
+    def add(
+        self,
+        *vmobjects: VMobject | Iterable[VMobject] | GeneratorType[VMobject],
+    ) -> Self:
+        """Checks if all passed elements are an instance, or iterables of VMobject and then adds them to submobjects
 
         Parameters
         ----------
         vmobjects
-            List of VMobject to add
+            List or iterable of VMobjects to add
 
         Returns
         -------
@@ -2084,7 +2094,7 @@
         Raises
         ------
         TypeError
-            If one element of the list is not an instance of VMobject
+            If one element of the list, or iterable is not an instance of VMobject
 
         Examples
         --------
@@ -2117,7 +2127,44 @@
                         (gr-circle_red).animate.shift(RIGHT)
                     )
         """
-        return super().add(*vmobjects)
+
+        def get_type_error_message(invalid_obj, invalid_i):
+            return (
+                f"Only values of type {vmobject_render_type.__name__} can be added "
+                f"as submobjects of VGroup, but the value "
+                f"{repr(invalid_obj)} (at index {invalid_i}) is of type "
+                f"{type(invalid_obj).__name__}."
+            )
+
+        vmobject_render_type = (
+            OpenGLVMobject if config.renderer == RendererType.OPENGL else VMobject
+        )
+        valid_vmobjects = []
+
+        for vmobject_i, vmobject in enumerate(vmobjects):
+            if isinstance(vmobject, vmobject_render_type):
+                valid_vmobjects.append(vmobject)
+            elif isinstance(vmobject, Iterable) and not isinstance(
+                vmobject, (Mobject, OpenGLMobject)
+            ):
+                for subvmobject_i, subvmobject in enumerate(vmobject):
+                    if not isinstance(subvmobject, vmobject_render_type):
+                        raise TypeError(
+                            get_type_error_message(subvmobject, subvmobject_i)
+                        )
+                    valid_vmobjects.append(subvmobject)
+            elif isinstance(vmobject, Iterable) and isinstance(
+                vmobject, (Mobject, OpenGLMobject)
+            ):
+                # This is if vmobject is an empty Mobject
+                raise TypeError(
+                    f"{get_type_error_message(vmobject, vmobject_i)} "
+                    "You can try adding this value into a Group instead."
+                )
+            else:
+                raise TypeError(get_type_error_message(vmobject, vmobject_i))
+
+        return super().add(*valid_vmobjects)
 
     def __add__(self, vmobject: VMobject) -> Self:
         return VGroup(*self.submobjects, vmobject)

tests/module/mobject/types/vectorized_mobject/test_vectorized_mobject.py

@@ -152,6 +152,49 @@ def test_vgroup_init():
     )
 
 
+def test_vgroup_init_with_iterable():
+    """Test VGroup instantiation with an iterable type."""
+
+    def type_generator(type_to_generate, n):
+        return (type_to_generate() for _ in range(n))
+
+    def mixed_type_generator(major_type, minor_type, minor_type_positions, n):
+        return (
+            minor_type() if i in minor_type_positions else major_type()
+            for i in range(n)
+        )
+
+    obj = VGroup(VMobject())
+    assert len(obj.submobjects) == 1
+
+    obj = VGroup(type_generator(VMobject, 38))
+    assert len(obj.submobjects) == 38
+
+    # A VGroup cannot be initialised with an iterable containing a Mobject
+    with pytest.raises(TypeError) as init_with_mob_iterable:
+        VGroup(type_generator(Mobject, 5))
+    assert str(init_with_mob_iterable.value) == (
+        "Only values of type VMobject can be added as submobjects of VGroup, "
+        "but the value Mobject (at index 0) is of type Mobject."
+    )
+
+    # A VGroup cannot be initialised with an iterable containing a Mobject in any position
+    with pytest.raises(TypeError) as init_with_mobs_and_vmobs_iterable:
+        VGroup(mixed_type_generator(VMobject, Mobject, [3, 5], 7))
+    assert str(init_with_mobs_and_vmobs_iterable.value) == (
+        "Only values of type VMobject can be added as submobjects of VGroup, "
+        "but the value Mobject (at index 3) is of type Mobject."
+    )
+
+    # A VGroup cannot be initialised with an iterable containing non VMobject's in any position
+    with pytest.raises(TypeError) as init_with_float_and_vmobs_iterable:
+        VGroup(mixed_type_generator(VMobject, float, [6, 7], 9))
+    assert str(init_with_float_and_vmobs_iterable.value) == (
+        "Only values of type VMobject can be added as submobjects of VGroup, "
+        "but the value 0.0 (at index 6) is of type float."
+    )
+
+
 def test_vgroup_add():
     """Test the VGroup add method."""
     obj = VGroup()

tests/opengl/test_opengl_vectorized_mobject.py

@@ -3,7 +3,7 @@
 import numpy as np
 import pytest
 
-from manim import Circle, Line, Square, VDict, VGroup
+from manim import Circle, Line, Square, VDict, VGroup, VMobject
 from manim.mobject.opengl.opengl_mobject import OpenGLMobject
 from manim.mobject.opengl.opengl_vectorized_mobject import OpenGLVMobject
 
@@ -110,6 +110,57 @@ def test_vgroup_init(using_opengl_renderer):
     )
 
 
+def test_vgroup_init_with_iterable(using_opengl_renderer):
+    """Test VGroup instantiation with an iterable type."""
+
+    def type_generator(type_to_generate, n):
+        return (type_to_generate() for _ in range(n))
+
+    def mixed_type_generator(major_type, minor_type, minor_type_positions, n):
+        return (
+            minor_type() if i in minor_type_positions else major_type()
+            for i in range(n)
+        )
+
+    obj = VGroup(OpenGLVMobject())
+    assert len(obj.submobjects) == 1
+
+    obj = VGroup(type_generator(OpenGLVMobject, 38))
+    assert len(obj.submobjects) == 38
+
+    # A VGroup cannot be initialised with an iterable containing a OpenGLMobject
+    with pytest.raises(TypeError) as init_with_mob_iterable:
+        VGroup(type_generator(OpenGLMobject, 5))
+    assert str(init_with_mob_iterable.value) == (
+        "Only values of type OpenGLVMobject can be added as submobjects of VGroup, "
+        "but the value OpenGLMobject (at index 0) is of type OpenGLMobject."
+    )
+
+    # A VGroup cannot be initialised with an iterable containing a OpenGLMobject in any position
+    with pytest.raises(TypeError) as init_with_mobs_and_vmobs_iterable:
+        VGroup(mixed_type_generator(OpenGLVMobject, OpenGLMobject, [3, 5], 7))
+    assert str(init_with_mobs_and_vmobs_iterable.value) == (
+        "Only values of type OpenGLVMobject can be added as submobjects of VGroup, "
+        "but the value OpenGLMobject (at index 3) is of type OpenGLMobject."
+    )
+
+    # A VGroup cannot be initialised with an iterable containing non OpenGLVMobject's in any position
+    with pytest.raises(TypeError) as init_with_float_and_vmobs_iterable:
+        VGroup(mixed_type_generator(OpenGLVMobject, float, [6, 7], 9))
+    assert str(init_with_float_and_vmobs_iterable.value) == (
+        "Only values of type OpenGLVMobject can be added as submobjects of VGroup, "
+        "but the value 0.0 (at index 6) is of type float."
+    )
+
+    # A VGroup cannot be initialised with an iterable containing both OpenGLVMobject's and VMobject's
+    with pytest.raises(TypeError) as init_with_mobs_and_vmobs_iterable:
+        VGroup(mixed_type_generator(OpenGLVMobject, VMobject, [3, 5], 7))
+    assert str(init_with_mobs_and_vmobs_iterable.value) == (
+        "Only values of type OpenGLVMobject can be added as submobjects of VGroup, "
+        "but the value VMobject (at index 3) is of type VMobject."
+    )
+
+
 def test_vgroup_add(using_opengl_renderer):
     """Test the VGroup add method."""
     obj = VGroup()