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, sync::Arc}; use helix_core::{syntax, Position}; use helix_view::{Editor, Theme}; pub struct Markdown { contents: String, config_loader: Arc, } // TODO: pre-render and self reference via Pin // better yet, just use Tendril + subtendril for references impl Markdown { pub fn new(contents: String, config_loader: Arc) -> Self { Self { contents, config_loader, } } } fn parse<'a>( contents: &'a str, theme: Option<&Theme>, loader: &syntax::Loader, ) -> 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>(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`](https://doc.rust-lang.org/nightly/core/result/enum.Result.html) items can be collected\ninto `Result, 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 = 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` on the left-hand side. This is because\nwe could collect into, for example, a [`VecDeque`](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 = 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::>();\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::>();\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`](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, &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, &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::>(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 = loader .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]), 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 text = text.replace('\t', " "); // replace tabs let span = Span::styled(text, 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.replace('\t', " "), 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), &self.config_loader); 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, &self.config_loader); 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)) } }