class CodeScene(MovingCameraScene):
CONFIG = {
"code_font": "Ubuntu Mono",
"text_font": "Helvetica",
"code_theme": "fruity",
}
def __init__(
self,
*args,
**kwargs,
):
super().__init__(*args, **kwargs)
self.caption = None
self.col_width = self.camera_frame.get_width() / 3
self.music: Optional[BackgroundMusic] = None
self.pauses = []
def add_background_music(self, path: str):
self.music = BackgroundMusic(path)
def tear_down(self):
super().tear_down()
if self.music:
self.time = 0
file = fit_audio(self.music.file, self.renderer.time + 2)
self.add_sound(file)
os.remove(file)
if self.pauses:
config[
"slide_videos"] = self.renderer.file_writer.partial_movie_files[:]
config["slide_stops"].extend(self.pauses)
config[
"movie_file_path"] = self.renderer.file_writer.movie_file_path
def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
if config.get("show_slides"):
print("In slide mode, skipping wait")
self.pauses.append(
len(self.renderer.file_writer.partial_movie_files) - 1)
else:
super().wait(duration, stop_condition)
def wait_until_beat(self, wait_time: Union[float, int]):
if self.music:
adjusted_delay = self.music.next_beat(
self.renderer.time + wait_time) - self.renderer.time
self.wait(adjusted_delay)
else:
self.wait(wait_time)
def wait_until_measure(self,
wait_time: Union[float, int],
post: Union[float, int] = 0):
if self.music:
adjusted_delay = self.music.next_measure(
self.renderer.time + wait_time) - self.renderer.time
adjusted_delay += post
self.wait(adjusted_delay)
else:
self.wait(wait_time)
def add_background(self, path: str) -> ImageMobject:
background = ImageMobject(path, height=self.camera_frame.get_height())
background.stretch_to_fit_width(self.camera_frame.get_width())
self.add(background)
return background
def animate_code_comments(
self,
path: str,
title: str = None,
keep_comments: bool = False,
start_line: int = 1,
end_line: Optional[int] = None,
reset_at_end: bool = True,
) -> Code:
parent = None
if title:
title = PangoText(title,
font=self.CONFIG["text_font"]).to_edge(edge=UP)
self.add(title)
code_group = VGroup().next_to(title, direction=DOWN)
self.add(code_group)
parent = code_group
code, comments = comment_parser.parse(path,
keep_comments=keep_comments,
start_line=start_line,
end_line=end_line)
with NamedTemporaryFile(suffix=f".{path.split('.')[-1]}") as f:
f.writelines([line.encode() for line in code])
f.flush()
tex = self.create_code(f.name, line_no_from=start_line)
if parent:
parent.add(tex)
self.play(ShowCreation(tex))
self.wait()
for comment in comments:
self.highlight_lines(tex, comment.start, comment.end,
comment.caption)
if reset_at_end:
self.highlight_none(tex)
return tex
def highlight_lines(self,
tex: Code,
start: int = 1,
end: int = -1,
caption: Optional[str] = None):
if end == -1:
end = len(tex.line_numbers) + 1
if hasattr(tex, "line_no_from"):
start -= tex.line_no_from - 1
end -= tex.line_no_from - 1
def in_range(number: int):
return start <= number <= end
pre_actions = []
actions = []
post_actions = []
if caption:
caption = "\n".join(wrap(caption, 25))
if self.caption:
pre_actions.append(FadeOut(self.caption))
else:
self.play(ApplyMethod(tex.to_edge))
self.caption = PangoText(
caption,
font=self.CONFIG["text_font"],
size=self.col_width / 10 *
0.9).add_background_rectangle(buff=MED_SMALL_BUFF)
self.caption.next_to(tex, RIGHT)
self.caption.align_to(tex.line_numbers[start - 1], UP)
actions.append(FadeIn(self.caption))
elif self.caption:
actions.append(FadeOut(self.caption))
post_actions += [ApplyMethod(tex.center)]
self.caption = None
# highlight code lines
actions += [
ApplyMethod(
tex.code[line_no].set_opacity,
1 if in_range(line_no + 1) else 0.3,
) for line_no in range(len(tex.code))
]
# highlight line numbers
actions += [
ApplyMethod(
tex.line_numbers[line_no].set_opacity,
1 if in_range(line_no + 1) else 0.3,
) for line_no in range(len(tex.code))
]
if pre_actions:
self.play(*pre_actions)
if actions:
self.play(*actions)
if caption:
wait_time = len(caption) / (200 * 5 / 60)
self.wait_until_measure(wait_time, -1.5)
if post_actions:
self.play(*post_actions)
def highlight_line(self,
tex: Code,
number: int = -1,
caption: Optional[str] = None):
return self.highlight_lines(tex, number, number, caption=caption)
def highlight_none(self, tex: Code):
start_line = tex.line_no_from
return self.highlight_lines(tex,
start_line,
len(tex.code) + start_line,
caption=None)
def create_code(self, path: str, **kwargs) -> Code:
tex = Code(path,
font=self.CONFIG["code_font"],
style=self.CONFIG["code_theme"],
**kwargs)
x_scale = (self.col_width * 2) / tex.get_width()
y_scale = self.camera_frame.get_height() * 0.95 / tex.get_height()
tex.scale(min(x_scale, y_scale))
return tex
class CodeScene(MovingCameraScene):
"""
This class serves as a convenience class for animating code walkthroughs in as
little work as possible. For more control, use `Code` or `PartialCode`
with the `HighlightLines` and `HighlightNone` transitions directly.
"""
def __init__(
self,
*args,
code_font="Ubuntu Mono",
text_font="Helvetica",
code_theme="fruity",
**kwargs,
):
super().__init__(*args, **kwargs)
self.caption = None
self.code_font = code_font
self.text_font = text_font
self.code_theme = code_theme
self.col_width = None
self.music: Optional[BackgroundMusic] = None
self.pauses = {}
def setup(self):
super().setup()
self.col_width = self.camera_frame.get_width() / 3
def add_background_music(self, path: str) -> CodeScene:
"""
Adds background music for the video. Can be combined with
`wait_util_beat` or
`wait_until_measure` to automatically time
animations
Args:
path: The file path of the music file, usually an mp3 file.
"""
self.music = BackgroundMusic(path)
return self
def tear_down(self):
super().tear_down()
if self.music:
self.time = 0
file = fit_audio(self.music.file, self.renderer.time + 2)
self.add_sound(file)
os.remove(file)
if self.pauses:
config[
"slide_videos"] = self.renderer.file_writer.partial_movie_files[:]
config["slide_stops"].update(self.pauses)
config[
"movie_file_path"] = self.renderer.file_writer.movie_file_path
def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
"""
Either waits like normal or if the codevidgen script is used and the "--slides" flag is used,
it will treat these calls as breaks between slides
"""
if config.get("show_slides"):
print("In slide mode, skipping wait")
super().wait(0.5)
index = len(self.renderer.file_writer.partial_movie_files) - 1
self.pauses[index] = []
else:
super().wait(duration, stop_condition)
def play_movie(self, path: str):
if config.get("show_slides"):
index = len(self.renderer.file_writer.partial_movie_files) - 1
self.pauses[index].append(path)
def wait_until_beat(self, wait_time: Union[float, int]):
"""
Waits until the next music beat, only works with `add_background_music`
"""
if self.music:
adjusted_delay = self.music.next_beat(
self.renderer.time + wait_time) - self.renderer.time
self.wait(adjusted_delay)
else:
self.wait(wait_time)
def wait_until_measure(self,
wait_time: Union[float, int],
post: Union[float, int] = 0):
"""
Waits until the next music measure, only works with `add_background_music`
"""
if self.music:
adjusted_delay = self.music.next_measure(
self.renderer.time + wait_time) - self.renderer.time
adjusted_delay += post
self.wait(adjusted_delay)
else:
self.wait(wait_time)
def add_background(self, path: str) -> ImageMobject:
"""
Adds a full screen background image. The image will be stretched to the full width.
Args:
path: The file path of the image file
"""
background = ImageMobject(path, height=self.camera_frame.get_height())
background.stretch_to_fit_width(self.camera_frame.get_width())
self.add(background)
return background
def animate_code_comments(
self,
path: str,
title: str = None,
keep_comments: bool = False,
start_line: int = 1,
end_line: Optional[int] = None,
reset_at_end: bool = True,
) -> Code:
"""
Parses a code file, displays it or a section of it, and animates comments
Args:
path: The source code file path
title: The title or file path if not provided
keep_comments: Whether to keep comments or strip them when displaying
start_line: The start line number, used for displaying only a partial file
end_line: The end line number, defaults to the end of the file
reset_at_end: Whether to reset the code to full screen at the end or not
"""
code, comments = comment_parser.parse(path,
keep_comments=keep_comments,
start_line=start_line,
end_line=end_line)
tex = AutoScaled(
PartialCode(code=code,
start_line=start_line,
style=self.code_theme))
if title is None:
title = path
title = Text(title, color=WHITE).to_edge(edge=UP)
self.add(title)
tex.next_to(title, DOWN)
self.play(ShowCreation(tex))
self.wait()
for comment in comments:
self.highlight_lines(tex, comment.start, comment.end,
comment.caption)
if self.caption:
self.play(FadeOut(self.caption))
self.caption = None
if reset_at_end:
self.play(HighlightNone(tex))
self.play(ApplyMethod(tex.full_size))
return tex
def highlight_lines(self,
code: Code,
start: int = 1,
end: int = -1,
caption: Optional[str] = None):
"""
Convenience method for animating a code object.
Args:
code: The code object, must be wrapped in `AutoScaled`
start: The start line number
end: The end line number, defaults to the end of the file
caption: The text to display with the highlight
"""
if end == -1:
end = len(code.line_numbers) + code.line_no_from
layout = ColumnLayout(columns=3)
actions = []
if caption and not self.caption:
self.play(
ApplyMethod(
code.fill_between_x,
layout.get_x(1, span=2, direction=LEFT),
layout.get_x(1, span=2, direction=RIGHT),
))
if self.caption:
actions.append(FadeOut(self.caption))
self.caption = None
if not caption:
self.play(ApplyMethod(code.full_size))
else:
callout = TextBox(caption,
text_attrs=dict(size=0.4, font=DEFAULT_FONT))
callout.align_to(code.line_numbers[start - code.line_no_from], UP)
callout.set_x(layout.get_x(3), LEFT)
actions += [HighlightLines(code, start, end), FadeIn(callout)]
self.caption = callout
self.play(*actions)
if not self.caption:
self.play(ApplyMethod(code.full_size))
else:
wait_time = len(self.caption.text) / (200 * 5 / 60)
self.wait_until_measure(wait_time, -1.5)
def highlight_line(self,
code: Code,
number: int = -1,
caption: Optional[str] = None):
"""
Convenience method for highlighting a single line
Args:
code: The code object, must be wrapped in `AutoScaled`
number: The line number
caption: The text to display with the highlight
"""
return self.highlight_lines(code, number, number, caption=caption)
def highlight_none(self, code: Code):
"""
Convenience method for resetting any existing highlighting.
Args:
code: The code object, must be wrapped in `AutoScaled`
"""
if self.caption:
self.play(FadeOut(self.caption), HighlightNone(code))
self.caption = None
self.play(ApplyMethod(code.full_size))
def create_code(self, path: str, **kwargs) -> Code:
"""
Convenience method for creating an autoscaled code object.
Args:
path: The source code file path
"""
return AutoScaled(
Code(path, font=self.code_font, style=self.code_theme, **kwargs))