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use crate::compositor::{Component, Compositor, Context, EventResult};
use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
use tui::{
buffer::Buffer as Surface,
layout::Rect,
style::{Color, Style},
text::Text,
};
use std::borrow::Cow;
use helix_core::Position;
use helix_view::{Editor, Theme};
pub struct Markdown {
contents: String,
}
// TODO: pre-render and self reference via Pin
// better yet, just use Tendril + subtendril for references
impl Markdown {
pub fn new(contents: String) -> Self {
Self { contents }
}
}
fn parse<'a>(contents: &'a str, theme: Option<&Theme>) -> tui::text::Text<'a> {
use pulldown_cmark::{CodeBlockKind, CowStr, Event, Options, Parser, Tag};
use tui::text::{Span, Spans, Text};
// also 2021-03-04T16:33:58.553 helix_lsp::transport [INFO] <- {"contents":{"kind":"markdown","value":"\n```rust\ncore::num\n```\n\n```rust\npub const fn saturating_sub(self, rhs:Self) ->Self\n```\n\n---\n\n```rust\n```"},"range":{"end":{"character":61,"line":101},"start":{"character":47,"line":101}}}
let text = "\n```rust\ncore::iter::traits::iterator::Iterator\n```\n\n```rust\nfn collect<B: FromIterator<Self::Item>>(self) -> B\nwhere\n Self: Sized,\n```\n\n---\n\nTransforms an iterator into a collection.\n\n`collect()` can take anything iterable, and turn it into a relevant\ncollection. This is one of the more powerful methods in the standard\nlibrary, used in a variety of contexts.\n\nThe most basic pattern in which `collect()` is used is to turn one\ncollection into another. You take a collection, call [`iter`](https://doc.rust-lang.org/nightly/core/iter/traits/iterator/trait.Iterator.html) on it,\ndo a bunch of transformations, and then `collect()` at the end.\n\n`collect()` can also create instances of types that are not typical\ncollections. For example, a [`String`](https://doc.rust-lang.org/nightly/core/iter/std/string/struct.String.html) can be built from [`char`](type@char)s,\nand an iterator of [`Result<T, E>`](https://doc.rust-lang.org/nightly/core/result/enum.Result.html) items can be collected\ninto `Result<Collection<T>, E>`. See the examples below for more.\n\nBecause `collect()` is so general, it can cause problems with type\ninference. As such, `collect()` is one of the few times you'll see\nthe syntax affectionately known as the 'turbofish': `::<>`. This\nhelps the inference algorithm understand specifically which collection\nyou're trying to collect into.\n\n# Examples\n\nBasic usage:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled: Vec<i32> = a.iter()\n .map(|&x| x * 2)\n .collect();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nNote that we needed the `: Vec<i32>` on the left-hand side. This is because\nwe could collect into, for example, a [`VecDeque<T>`](https://doc.rust-lang.org/nightly/core/iter/std/collections/struct.VecDeque.html) instead:\n\n```rust\nuse std::collections::VecDeque;\n\nlet a = [1, 2, 3];\n\nlet doubled: VecDeque<i32> = a.iter().map(|&x| x * 2).collect();\n\nassert_eq!(2, doubled[0]);\nassert_eq!(4, doubled[1]);\nassert_eq!(6, doubled[2]);\n```\n\nUsing the 'turbofish' instead of annotating `doubled`:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled = a.iter().map(|x| x * 2).collect::<Vec<i32>>();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nBecause `collect()` only cares about what you're collecting into, you can\nstill use a partial type hint, `_`, with the turbofish:\n\n```rust\nlet a = [1, 2, 3];\n\nlet doubled = a.iter().map(|x| x * 2).collect::<Vec<_>>();\n\nassert_eq!(vec![2, 4, 6], doubled);\n```\n\nUsing `collect()` to make a [`String`](https://doc.rust-lang.org/nightly/core/iter/std/string/struct.String.html):\n\n```rust\nlet chars = ['g', 'd', 'k', 'k', 'n'];\n\nlet hello: String = chars.iter()\n .map(|&x| x as u8)\n .map(|x| (x + 1) as char)\n .collect();\n\nassert_eq!(\"hello\", hello);\n```\n\nIf you have a list of [`Result<T, E>`](https://doc.rust-lang.org/nightly/core/result/enum.Result.html)s, you can use `collect()` to\nsee if any of them failed:\n\n```rust\nlet results = [Ok(1), Err(\"nope\"), Ok(3), Err(\"bad\")];\n\nlet result: Result<Vec<_>, &str> = results.iter().cloned().collect();\n\n// gives us the first error\nassert_eq!(Err(\"nope\"), result);\n\nlet results = [Ok(1), Ok(3)];\n\nlet result: Result<Vec<_>, &str> = results.iter().cloned().collect();\n\n// gives us the list of answers\nassert_eq!(Ok(vec![1, 3]), result);\n```";
let mut options = Options::empty();
options.insert(Options::ENABLE_STRIKETHROUGH);
let parser = Parser::new_ext(contents, options);
// TODO: if possible, render links as terminal hyperlinks: https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
let mut tags = Vec::new();
let mut spans = Vec::new();
let mut lines = Vec::new();
fn to_span(text: pulldown_cmark::CowStr) -> Span {
use std::ops::Deref;
Span::raw::<std::borrow::Cow<_>>(match text {
CowStr::Borrowed(s) => s.to_string().into(), // could retain borrow
CowStr::Boxed(s) => s.to_string().into(),
CowStr::Inlined(s) => s.deref().to_owned().into(),
})
}
let text_style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender
let code_style = Style::default().fg(Color::Rgb(255, 255, 255)); // white
let heading_style = Style::default().fg(Color::Rgb(219, 191, 239)); // lilac
for event in parser {
match event {
Event::Start(tag) => tags.push(tag),
Event::End(tag) => {
tags.pop();
match tag {
Tag::Heading(_) | Tag::Paragraph | Tag::CodeBlock(CodeBlockKind::Fenced(_)) => {
// whenever code block or paragraph closes, new line
let spans = std::mem::take(&mut spans);
if !spans.is_empty() {
lines.push(Spans::from(spans));
}
lines.push(Spans::default());
}
_ => (),
}
}
Event::Text(text) => {
// TODO: temp workaround
if let Some(Tag::CodeBlock(CodeBlockKind::Fenced(language))) = tags.last() {
if let Some(theme) = theme {
use helix_core::syntax::{self, HighlightEvent, Syntax};
use helix_core::Rope;
let rope = Rope::from(text.as_ref());
let syntax = syntax::LOADER
.get()
.unwrap()
.language_config_for_scope(&format!("source.{}", language))
.and_then(|config| config.highlight_config(theme.scopes()))
.map(|config| Syntax::new(&rope, config));
if let Some(mut syntax) = syntax {
// if we have a syntax available, highlight_iter and generate spans
let mut highlights = Vec::new();
for event in syntax.highlight_iter(rope.slice(..), None, None, |_| None)
{
match event.unwrap() {
HighlightEvent::HighlightStart(span) => {
highlights.push(span);
}
HighlightEvent::HighlightEnd => {
highlights.pop();
}
HighlightEvent::Source { start, end } => {
let style = match highlights.first() {
Some(span) => {
theme.get(theme.scopes()[span.0].as_str())
}
None => text_style,
};
// TODO: replace tabs with indentation
let mut slice = &text[start..end];
while let Some(end) = slice.find('\n') {
// emit span up to newline
let text = &slice[..end];
let span = Span::styled(text.to_owned(), style);
spans.push(span);
// truncate slice to after newline
slice = &slice[end + 1..];
// make a new line
let spans = std::mem::take(&mut spans);
lines.push(Spans::from(spans));
}
// if there's anything left, emit it too
if !slice.is_empty() {
let span = Span::styled(slice.to_owned(), style);
spans.push(span);
}
}
}
}
} else {
for line in text.lines() {
let mut span = Span::styled(line.to_string(), code_style);
lines.push(Spans::from(span));
}
}
} else {
for line in text.lines() {
let mut span = Span::styled(line.to_string(), code_style);
lines.push(Spans::from(span));
}
}
} else if let Some(Tag::Heading(_)) = tags.last() {
let mut span = to_span(text);
span.style = heading_style;
spans.push(span);
} else {
let mut span = to_span(text);
span.style = text_style;
spans.push(span);
}
}
Event::Code(text) | Event::Html(text) => {
log::warn!("code {:?}", text);
let mut span = to_span(text);
span.style = code_style;
spans.push(span);
}
Event::SoftBreak | Event::HardBreak => {
// let spans = std::mem::replace(&mut spans, Vec::new());
// lines.push(Spans::from(spans));
spans.push(Span::raw(" "));
}
Event::Rule => {
lines.push(Spans::from("---"));
lines.push(Spans::default());
}
// TaskListMarker(bool) true if checked
_ => {
log::warn!("unhandled markdown event {:?}", event);
}
}
// build up a vec of Paragraph tui widgets
}
if !spans.is_empty() {
lines.push(Spans::from(spans));
}
// if last line is empty, remove it
if let Some(line) = lines.last() {
if line.0.is_empty() {
lines.pop();
}
}
Text::from(lines)
}
impl Component for Markdown {
fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
use tui::widgets::{Paragraph, Widget, Wrap};
let text = parse(&self.contents, Some(&cx.editor.theme));
let par = Paragraph::new(text)
.wrap(Wrap { trim: false })
.scroll((cx.scroll.unwrap_or_default() as u16, 0));
let area = Rect::new(area.x + 1, area.y + 1, area.width - 2, area.height - 2);
par.render(area, surface);
}
fn required_size(&mut self, viewport: (u16, u16)) -> Option<(u16, u16)> {
let contents = parse(&self.contents, None);
let padding = 2;
let width = std::cmp::min(contents.width() as u16 + padding, viewport.0);
let height = std::cmp::min(contents.height() as u16 + padding, viewport.1);
Some((width, height))
}
}
|
