@@ -0,0 +1,137 @@
1+use crate::compositor::{Component, Compositor, Context, EventResult};
2+use crossterm::event::{Event, KeyCode, KeyEvent, KeyModifiers};
3+use tui::buffer::Buffer as Surface;
4+use tui::{
5+ layout::Rect,
6+ style::{Color, Style},
7+ text::Text,
8+};
9+
10+use std::borrow::Cow;
11+
12+use helix_core::Position;
13+use helix_view::Editor;
14+
15+pub struct Markdown {
16+ contents: String,
17+}
18+
19+impl Markdown {
20+ pub fn new(contents: String) -> Self {
21+ Self { contents }
22+ }
23+}
24+impl Component for Markdown {
25+ fn render(&self, area: Rect, surface: &mut Surface, cx: &mut Context) {
26+ use tui::widgets::{Paragraph, Widget, Wrap};
27+
28+ use pulldown_cmark::{CodeBlockKind, CowStr, Event, Options, Parser, Tag};
29+ use tui::text::{Span, Spans, Text};
30+
31+ // 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}}}
32+ 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```";
33+
34+ let mut options = Options::empty();
35+ options.insert(Options::ENABLE_STRIKETHROUGH);
36+ let parser = Parser::new_ext(&self.contents, options);
37+
38+ // TODO: if possible, render links as terminal hyperlinks: https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
39+ let mut tags = Vec::new();
40+ let mut spans = Vec::new();
41+ let mut lines = Vec::new();
42+
43+ fn to_span(text: pulldown_cmark::CowStr) -> Span {
44+ use std::ops::Deref;
45+ Span::raw::<std::borrow::Cow<_>>(match text {
46+ CowStr::Borrowed(s) => s.into(),
47+ CowStr::Boxed(s) => s.to_string().into(),
48+ CowStr::Inlined(s) => s.deref().to_owned().into(),
49+ })
50+ }
51+
52+ let text_style = Style::default().fg(Color::Rgb(164, 160, 232)); // lavender
53+ let code_style = Style::default().fg(Color::Rgb(255, 255, 255)); // white
54+ let heading_style = Style::default().fg(Color::Rgb(219, 191, 239)); // lilac
55+
56+ for event in parser {
57+ match event {
58+ Event::Start(tag) => tags.push(tag),
59+ Event::End(tag) => {
60+ tags.pop();
61+ match tag {
62+ Tag::Heading(_) | Tag::Paragraph => {
63+ // whenever paragraph closes, new line
64+ let spans = std::mem::replace(&mut spans, Vec::new());
65+ lines.push(Spans::from(spans));
66+ lines.push(Spans::default());
67+ }
68+ Tag::CodeBlock(CodeBlockKind::Fenced(_)) => {
69+ let spans = std::mem::replace(&mut spans, Vec::new());
70+ lines.push(Spans::from(spans));
71+ }
72+ _ => (),
73+ }
74+ }
75+ Event::Text(text) => {
76+ if let Some(Tag::CodeBlock(CodeBlockKind::Fenced(_))) = tags.last() {
77+ for line in text.lines() {
78+ let mut span = Span::styled(line.to_string(), code_style);
79+ lines.push(Spans::from(span));
80+ }
81+ } else if let Some(Tag::Heading(_)) = tags.last() {
82+ let mut span = to_span(text);
83+ span.style = heading_style;
84+ spans.push(span);
85+ } else {
86+ let mut span = to_span(text);
87+ span.style = text_style;
88+ spans.push(span);
89+ }
90+ }
91+ Event::Code(text) | Event::Html(text) => {
92+ let mut span = to_span(text);
93+ span.style = code_style;
94+ spans.push(span);
95+ }
96+ Event::SoftBreak | Event::HardBreak => {
97+ // let spans = std::mem::replace(&mut spans, Vec::new());
98+ // lines.push(Spans::from(spans));
99+ spans.push(Span::raw(" "));
100+ }
101+ Event::Rule => {
102+ lines.push(Spans::from("---"));
103+ lines.push(Spans::default());
104+ }
105+ // TaskListMarker(bool) true if checked
106+ _ => (),
107+ }
108+ // build up a vec of Paragraph tui widgets
109+ }
110+
111+ if !spans.is_empty() {
112+ lines.push(Spans::from(spans));
113+ }
114+
115+ let contents = Text::from(lines);
116+
117+ let par = Paragraph::new(contents).wrap(Wrap { trim: false });
118+ // .scroll(x, y) offsets
119+
120+ // padding on all sides
121+ let area = Rect::new(area.x + 1, area.y + 1, area.width - 2, area.height - 2);
122+ par.render(area, surface);
123+ }
124+
125+ fn size_hint(&self, area: Rect) -> Option<(usize, usize)> {
126+ let contents = tui::text::Text::from(self.contents.clone());
127+ Some((contents.width(), contents.height()))
128+ }
129+}
130+
131+#[cfg(test)]
132+mod test {
133+ use super::*;
134+
135+ #[test]
136+ fn it_works() {}
137+}