feat(cli): add convert option to generate html presentations (#66)

* wip(cli): convert slides to html using RevealJS

* wip: convert - almost fully working

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* fix: remove unused file

* fix: add last slides in now performed during rendering

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* chore(ci): testing ConvertExample too

* fix: ManimGL does not consider wait as an animation

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

manim_slides/convert.py

@@ -0,0 +1,200 @@
+import os
+import webbrowser
+from enum import Enum
+from typing import Any, Callable, Dict, Generator, List, Type
+
+import click
+from click import Context, Parameter
+from pydantic import BaseModel
+
+from .commons import folder_path_option, verbosity_option
+from .config import PresentationConfig
+from .defaults import REVEALJS_TEMPLATE
+from .present import get_scenes_presentation_config
+
+
+def validate_config_option(
+    ctx: Context, param: Parameter, value: Any
+) -> Dict[str, str]:
+
+    config = {}
+
+    for c_option in value:
+        try:
+            key, value = c_option.split("=")
+            config[key] = value
+        except ValueError:
+            raise click.BadParameter(
+                f"Configuration options `{c_option}` could not be parsed into a proper (key, value) pair. Please use an `=` sign to separate key from value."
+            )
+
+    return config
+
+
+class Converter(BaseModel):
+    presentation_configs: List[PresentationConfig] = []
+    assets_dir: str = "{basename}_assets"
+
+    def convert_to(self, dest: str):
+        """Converts self, i.e., a list of presentations, into a given format."""
+        raise NotImplementedError
+
+    def open(self, file: str) -> bool:
+        """Opens a file, generated with converter, using appropriate application."""
+        return webbrowser.open(file)
+
+    @classmethod
+    def from_string(cls, s: str) -> Type["Converter"]:
+        """Returns the appropriate converter from a string name."""
+        return {
+            "html": RevealJS,
+        }[s]
+
+
+class JSBool(str, Enum):
+    true = "true"
+    false = "false"
+
+
+class RevealTheme(str, Enum):
+    black = "black"
+    white = "white"
+    league = "league"
+    beige = "beige"
+    sky = "sky"
+    night = "night"
+    serif = "serif"
+    simple = "simple"
+    soralized = "solarized"
+    blood = "blood"
+    moon = "moon"
+
+
+class RevealJS(Converter):
+    background_color: str = "black"
+    controls: JSBool = JSBool.false
+    embedded: JSBool = JSBool.false
+    fragments: JSBool = JSBool.false
+    height: str = "100%"
+    loop: JSBool = JSBool.false
+    progress: JSBool = JSBool.false
+    reveal_version: str = "3.7.0"
+    reveal_theme: RevealTheme = RevealTheme.black
+    shuffle: JSBool = JSBool.false
+    title: str = "Manim Slides"
+    width: str = "100%"
+
+    class Config:
+        use_enum_values = True
+
+    def get_sections_iter(self) -> Generator[str, None, None]:
+        """Generates a sequence of sections, one per slide, that will be included into the html template."""
+        for presentation_config in self.presentation_configs:
+            for slide_config in presentation_config.slides:
+                file = presentation_config.files[slide_config.start_animation]
+                file = os.path.join(self.assets_dir, os.path.basename(file))
+
+                if slide_config.is_loop():
+                    yield f'<section data-background-video="{file}" data-background-video-loop></section>'
+                else:
+                    yield f'<section data-background-video="{file}"></section>'
+
+    def convert_to(self, dest: str):
+        dirname = os.path.dirname(dest)
+        basename, ext = os.path.splitext(os.path.basename(dest))
+
+        self.assets_dir = self.assets_dir.format(
+            dirname=dirname, basename=basename, ext=ext
+        )
+        full_assets_dir = os.path.join(dirname, self.assets_dir)
+
+        os.makedirs(full_assets_dir, exist_ok=True)
+
+        for presentation_config in self.presentation_configs:
+            presentation_config.concat_animations().move_to(full_assets_dir)
+
+        with open(dest, "w") as f:
+
+            sections = "".join(self.get_sections_iter())
+
+            content = REVEALJS_TEMPLATE.format(sections=sections, **self.dict())
+
+            f.write(content)
+
+
+def show_config_options(function: Callable) -> Callable:
+    """Wraps a function to add a `--show-config` option."""
+
+    def callback(ctx: Context, param: Parameter, value: bool) -> None:
+
+        if not value or ctx.resilient_parsing:
+            return
+
+        to = ctx.params.get("to")
+
+        if to:
+            converter = Converter.from_string(to)(scenes=[])
+            for key, value in converter.dict().items():
+                click.echo(f"{key}: {repr(value)}")
+
+            ctx.exit()
+
+        else:
+            raise click.UsageError(
+                "Using --show-config option requires to first specify --to option."
+            )
+
+    return click.option(
+        "--show-config",
+        is_flag=True,
+        help="Show supported options for given format and exit.",
+        default=None,
+        expose_value=False,
+        show_envvar=True,
+        callback=callback,
+    )(function)
+
+
+@click.command()
+@click.argument("scenes", nargs=-1)
+@folder_path_option
+@click.argument("dest")
+@click.option(
+    "--to",
+    type=click.Choice(["html"], case_sensitive=False),
+    default="html",
+    show_default=True,
+    help="Set the conversion format to use.",
+)
+@click.option(
+    "--open",
+    "open_result",
+    is_flag=True,
+    help="Open the newly created file using the approriate application.",
+)
+@click.option("-f", "--force", is_flag=True, help="Overwrite any existing file.")
+@click.option(
+    "-c",
+    "--config",
+    "config_options",
+    multiple=True,
+    callback=validate_config_option,
+    help="Configuration options passed to the converter. E.g., pass `-cbackground_color=red` to set the background color to red (if supported).",
+)
+@show_config_options
+@verbosity_option
+def convert(scenes, folder, dest, to, open_result, force, config_options):
+    """
+    Convert SCENE(s) into a given format and writes the result in DEST.
+    """
+
+    presentation_configs = get_scenes_presentation_config(scenes, folder)
+
+    converter = Converter.from_string(to)(
+        presentation_configs=presentation_configs, **config_options
+    )
+
+    converter.convert_to(dest)
+
+    if open_result:
+        converter.open(dest)