feat(lib): add skip_animations compatibility (#516)

* feat: Add skip_animations compatibility

* Add tests, config and changelog

* chore(fmt): auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Update manim_slides/slide/base.py

Co-authored-by: Jérome Eertmans <jeertmans@icloud.com>

* chore(fmt): auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* chore(tests): implement tests

---------

Co-authored-by: Jérome Eertmans <jeertmans@icloud.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -10,6 +10,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 (unreleased)=
 ## [Unreleased](https://github.com/jeertmans/manim-slides/compare/v5.3.1...HEAD)
 
+(unreleased-added)=
+### Added
+
+- Added `skip_animations` compatibility with ManimCE.
+  [@Rapsssito](https://github.com/Rapsssito) [#516](https://github.com/jeertmans/manim-slides/pull/516)
+
 (v5.3.1)=
 ## [v5.3.1](https://github.com/jeertmans/manim-slides/compare/v5.3.0...v5.3.1)
 

manim_slides/config.py

@@ -160,6 +160,7 @@ class BaseSlideConfig(BaseModel):  # type: ignore
     reversed_playback_rate: float = 1.0
     notes: str = ""
     dedent_notes: bool = True
+    skip_animations: bool = False
 
     @classmethod
     def wrapper(cls, arg_name: str) -> Callable[..., Any]:

manim_slides/slide/base.py

@@ -277,7 +277,7 @@ def wait_time_between_slides(self, wait_time: float) -> None:
         self._wait_time_between_slides = max(wait_time, 0.0)
 
     def play(self, *args: Any, **kwargs: Any) -> None:
-        """Overload `self.play` and increment animation count."""
+        """Overload 'self.play' and increment animation count."""
         super().play(*args, **kwargs)  # type: ignore[misc]
         self._current_animation += 1
 
@@ -299,6 +299,11 @@ def next_slide(
             Positional arguments passed to
             :meth:`Scene.next_section<manim.scene.scene.Scene.next_section>`,
             or ignored if `manimlib` API is used.
+        :param skip_animations:
+            Exclude the next slide from the output.
+
+            If `manim` is used, this is also passed to `:meth:`Scene.next_section<manim.scene.scene.Scene.next_section>`,
+            which will avoid rendering the corresponding animations.
         :param loop:
             If set, next slide will be looping.
         :param auto_next:
@@ -521,9 +526,16 @@ def _save_slides(
             ascii=True if platform.system() == "Windows" else None,
             disable=not self._show_progress_bar,
         ):
+            if pre_slide_config.skip_animations:
+                continue
             slide_files = files[pre_slide_config.slides_slice]
 
-            file = merge_basenames(slide_files)
+            try:
+                file = merge_basenames(slide_files)
+            except ValueError as e:
+                raise ValueError(
+                    f"Failed to merge basenames of files for slide: {pre_slide_config!r}"
+                ) from e
             dst_file = scene_files_folder / file.name
             rev_file = scene_files_folder / f"{file.stem}_reversed{file.suffix}"
 

manim_slides/slide/manim.py

@@ -89,6 +89,15 @@ def _leave_progress_bar(self) -> bool:
     def _start_at_animation_number(self) -> Optional[int]:
         return config["from_animation_number"]  # type: ignore
 
+    def play(self, *args: Any, **kwargs: Any) -> None:
+        """Overload 'self.play' and increment animation count."""
+        super().play(*args, **kwargs)
+
+        if self._base_slide_config.skip_animations:
+            # Manim will not render the animations, so we reset the animation
+            # counter to the previous value
+            self._current_animation -= 1
+
     def next_section(self, *args: Any, **kwargs: Any) -> None:
         """
         Alias to :meth:`next_slide`.
@@ -111,7 +120,9 @@ def next_slide(
         base_slide_config: BaseSlideConfig,
         **kwargs: Any,
     ) -> None:
-        Scene.next_section(self, *args, **kwargs)
+        Scene.next_section(
+            self, *args, skip_animations=base_slide_config.skip_animations, **kwargs
+        )
         BaseSlide.next_slide.__wrapped__(
             self,
             base_slide_config=base_slide_config,

tests/test_slide.py

@@ -1,6 +1,11 @@
+import contextlib
+import os
 import random
 import shutil
 import sys
+import tempfile
+import threading
+from collections.abc import Iterator
 from pathlib import Path
 from typing import Any, Union
 
@@ -17,6 +22,7 @@
     Dot,
     FadeIn,
     GrowFromCenter,
+    Square,
     Text,
 )
 from manim.renderer.opengl_renderer import OpenGLRenderer
@@ -229,8 +235,26 @@ def assert_constructs(cls: SlideType) -> None:
     init_slide(cls).construct()
 
 
+_L = (
+    threading.Lock()
+)  # We cannot change directory multiple times at once (in the same thread)
+
+
+@contextlib.contextmanager
+def tmp_cwd() -> Iterator[str]:
+    old_cwd = os.getcwd()
+
+    with tempfile.TemporaryDirectory() as tmp_dir, _L:
+        try:
+            os.chdir(tmp_dir)
+            yield tmp_dir
+        finally:
+            os.chdir(old_cwd)
+
+
 def assert_renders(cls: SlideType) -> None:
-    init_slide(cls).render()
+    with tmp_cwd():
+        init_slide(cls).render()
 
 
 class TestSlide:
@@ -479,6 +503,53 @@ def construct(self) -> None:
                 self.next_slide()
                 assert self._current_slide == 2
 
+    def test_next_slide_skip_animations(self) -> None:
+        class Foo(CESlide):
+            def construct(self) -> None:
+                circle = Circle(color=BLUE)
+                self.play(GrowFromCenter(circle))
+                assert not self._base_slide_config.skip_animations
+                self.next_slide(skip_animations=True)
+                square = Square(color=BLUE)
+                self.play(GrowFromCenter(square))
+                assert self._base_slide_config.skip_animations
+                self.next_slide()
+                assert not self._base_slide_config.skip_animations
+                self.play(GrowFromCenter(square))
+
+        class Bar(CESlide):
+            def construct(self) -> None:
+                circle = Circle(color=BLUE)
+                self.play(GrowFromCenter(circle))
+                assert not self._base_slide_config.skip_animations
+                self.next_slide(skip_animations=False)
+                square = Square(color=BLUE)
+                self.play(GrowFromCenter(square))
+                assert not self._base_slide_config.skip_animations
+                self.next_slide()
+                assert not self._base_slide_config.skip_animations
+                self.play(GrowFromCenter(square))
+
+        with tmp_cwd() as tmp_dir:
+            init_slide(Foo).render()
+            init_slide(Bar).render()
+
+            slides_folder = Path(tmp_dir) / "slides"
+
+            assert slides_folder.exists()
+
+            slide_file = slides_folder / "Foo.json"
+
+            config = PresentationConfig.from_file(slide_file)
+
+            assert len(config.slides) == 2
+
+            slide_file = slides_folder / "Bar.json"
+
+            config = PresentationConfig.from_file(slide_file)
+
+            assert len(config.slides) == 3
+
     def test_canvas(self) -> None:
         @assert_constructs
         class _(CESlide):