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178 | import marko
from marko.block import BlankLine, FencedCode, Heading, List, ListItem, Paragraph, Quote
from marko.inline import Emphasis, LineBreak, Link, RawText, StrongEmphasis
from ..boxtree.box import Box
from ..text.textparser import trim_indent
from ..text.textstyle import TextStyle as s
from . import ordered_list, unordered_list
def md_heading_style_name(level: int) -> str:
"""Returns the name of the text style used for Markdown headings of the given level."""
assert 1 <= level <= 6
return f"md-h{level}"
MD_PARAGRAPH_STYLE = "md-paragraph"
MD_BOLD_STYLE = "md-bold"
MD_ITALIC_STYLE = "md-italic"
MD_LINK_STYLE = "md-link"
MD_BLOCKQUOTE_STYLE = "md-blockquote"
MD_HEADING_1_STYLE = md_heading_style_name(1)
MD_HEADING_2_STYLE = md_heading_style_name(2)
MD_HEADING_3_STYLE = md_heading_style_name(3)
MD_HEADING_4_STYLE = md_heading_style_name(4)
MD_HEADING_5_STYLE = md_heading_style_name(5)
MD_HEADING_6_STYLE = md_heading_style_name(6)
class MarkdownContext:
def __init__(self, box: Box, escape_char: str, active_list=None):
self.box = box
self.escape_char = escape_char
self.text_kwargs = {"escape_char": escape_char}
self.active_list = active_list
def copy(self, **kwargs):
args = dict(
box=self.box, escape_char=self.escape_char, active_list=self.active_list
)
args.update(kwargs)
return MarkdownContext(**args)
def wrap_text_with_style(self, text: str, style: str):
return f"{self.escape_char}{style}{{{text}}}"
def get_raw_text(ctx: MarkdownContext, node) -> str:
text = ""
for child in node.children:
if isinstance(child, RawText):
text += child.children
elif isinstance(child, Emphasis):
text += ctx.wrap_text_with_style(get_raw_text(ctx, child), MD_ITALIC_STYLE)
elif isinstance(child, StrongEmphasis):
text += ctx.wrap_text_with_style(get_raw_text(ctx, child), MD_BOLD_STYLE)
elif isinstance(child, Link):
text += ctx.wrap_text_with_style(get_raw_text(ctx, child), MD_LINK_STYLE)
elif isinstance(child, LineBreak):
text += "\n"
return text
def create_root_md_box(box: Box) -> Box:
box = box.box()
default = s(align="left")
styles = {
MD_PARAGRAPH_STYLE: default.compose(s()),
MD_BOLD_STYLE: default.compose(s(bold=True)),
MD_ITALIC_STYLE: default.compose(s(italic=True)),
MD_LINK_STYLE: default.compose(s(color="#0EBFE9")),
MD_BLOCKQUOTE_STYLE: default.compose(s(color="#A9A9A9")),
}
for i in range(6):
styles[md_heading_style_name(i + 1)] = default.compose(s(size=40 - i * 2))
for (name, style) in styles.items():
if not box.has_style(name):
box.set_style(name, style)
return box
def build_text(ctx: MarkdownContext, text: str, style: str):
container = ctx.box.sbox()
container.text(text, style=style, **ctx.text_kwargs)
def build_heading(ctx: MarkdownContext, heading: Heading):
build_text(ctx, get_raw_text(ctx, heading), md_heading_style_name(heading.level))
def build_paragraph(ctx: MarkdownContext, paragraph: Paragraph):
build_text(ctx, get_raw_text(ctx, paragraph), MD_PARAGRAPH_STYLE)
def build_blank_line(ctx: MarkdownContext, blank_line: BlankLine):
build_text(ctx, "\n", MD_PARAGRAPH_STYLE)
def build_quote(ctx: MarkdownContext, quote: Quote):
container = ctx.box.sbox()
container.update_style("default", container.get_style(MD_BLOCKQUOTE_STYLE))
parent_ctx = ctx.copy(box=container)
for child in quote.children:
build(parent_ctx, child)
def build_fenced_code(ctx: MarkdownContext, fenced_code: FencedCode):
container = ctx.box.sbox()
container.code(fenced_code.lang, get_raw_text(ctx, fenced_code))
def build_list_top(ctx: MarkdownContext, list_node: List):
container = ctx.box.sbox()
if list_node.ordered:
if ctx.active_list:
new_list = ctx.active_list.ol(start=list_node.start, level=())
else:
new_list = ordered_list(container, start=list_node.start)
else:
if ctx.active_list:
new_list = ctx.active_list.ul(label=list_node.bullet)
else:
new_list = unordered_list(container, label=list_node.bullet)
for child in list_node.children:
assert isinstance(child, ListItem)
box = new_list.item()
build_children(ctx.copy(box=box, active_list=new_list), child)
MD_BUILD_FNS = {
Heading: build_heading,
Paragraph: build_paragraph,
BlankLine: build_blank_line,
Quote: build_quote,
FencedCode: build_fenced_code,
List: build_list_top,
}
def build(ctx: MarkdownContext, node):
cls = node.__class__
if cls in MD_BUILD_FNS:
MD_BUILD_FNS[cls](ctx, node)
else:
print(f"Warning: ignoring markdown node {node}")
def build_children(ctx: MarkdownContext, parent):
for node in parent.children:
build(ctx, node)
def markdown(root: Box, markup: str, escape_char="~") -> Box:
"""
Render Markdown markup into the given box.
The Markdown syntax has to adhere to the CommonMark spec, but only
a subset of the Markdown syntax is supported (see user guide).
Parameters
----------
root: Box
Parent box into which will the markup be rendered.
markup: str
Markdown markup.
escape_char: str
Escape character used for marking inline styles.
"""
markup = trim_indent(markup).strip()
document = marko.parse(markup)
wrapper = create_root_md_box(root)
ctx = MarkdownContext(wrapper, escape_char)
build_children(ctx, document)
return root
|