rich_text.rs

  1use futures::FutureExt;
  2use gpui::{
  3    AnyElement, ElementId, FontStyle, FontWeight, HighlightStyle, InteractiveText, IntoElement,
  4    SharedString, StyledText, UnderlineStyle, WindowContext,
  5};
  6use language::{HighlightId, Language, LanguageRegistry};
  7use std::{ops::Range, sync::Arc};
  8use theme::ActiveTheme;
  9use util::RangeExt;
 10
 11#[derive(Debug, Clone, PartialEq, Eq)]
 12pub enum Highlight {
 13    Code,
 14    Id(HighlightId),
 15    Highlight(HighlightStyle),
 16    Mention,
 17    SelfMention,
 18}
 19
 20impl From<HighlightStyle> for Highlight {
 21    fn from(style: HighlightStyle) -> Self {
 22        Self::Highlight(style)
 23    }
 24}
 25
 26impl From<HighlightId> for Highlight {
 27    fn from(style: HighlightId) -> Self {
 28        Self::Id(style)
 29    }
 30}
 31
 32#[derive(Debug, Clone)]
 33pub struct RichText {
 34    pub text: SharedString,
 35    pub highlights: Vec<(Range<usize>, Highlight)>,
 36    pub link_ranges: Vec<Range<usize>>,
 37    pub link_urls: Arc<[String]>,
 38}
 39
 40/// Allows one to specify extra links to the rendered markdown, which can be used
 41/// for e.g. mentions.
 42#[derive(Debug)]
 43pub struct Mention {
 44    pub range: Range<usize>,
 45    pub is_self_mention: bool,
 46}
 47
 48impl RichText {
 49    pub fn element(&self, id: ElementId, cx: &mut WindowContext) -> AnyElement {
 50        let theme = cx.theme();
 51        let code_background = theme.colors().surface_background;
 52
 53        InteractiveText::new(
 54            id,
 55            StyledText::new(self.text.clone()).with_highlights(
 56                &cx.text_style(),
 57                self.highlights.iter().map(|(range, highlight)| {
 58                    (
 59                        range.clone(),
 60                        match highlight {
 61                            Highlight::Code => HighlightStyle {
 62                                background_color: Some(code_background),
 63                                ..Default::default()
 64                            },
 65                            Highlight::Id(id) => HighlightStyle {
 66                                background_color: Some(code_background),
 67                                ..id.style(&theme.syntax()).unwrap_or_default()
 68                            },
 69                            Highlight::Highlight(highlight) => *highlight,
 70                            Highlight::Mention => HighlightStyle {
 71                                font_weight: Some(FontWeight::BOLD),
 72                                ..Default::default()
 73                            },
 74                            Highlight::SelfMention => HighlightStyle {
 75                                font_weight: Some(FontWeight::BOLD),
 76                                ..Default::default()
 77                            },
 78                        },
 79                    )
 80                }),
 81            ),
 82        )
 83        .on_click(self.link_ranges.clone(), {
 84            let link_urls = self.link_urls.clone();
 85            move |ix, cx| cx.open_url(&link_urls[ix])
 86        })
 87        .into_any_element()
 88    }
 89
 90    // pub fn add_mention(
 91    //     &mut self,
 92    //     range: Range<usize>,
 93    //     is_current_user: bool,
 94    //     mention_style: HighlightStyle,
 95    // ) -> anyhow::Result<()> {
 96    //     if range.end > self.text.len() {
 97    //         bail!(
 98    //             "Mention in range {range:?} is outside of bounds for a message of length {}",
 99    //             self.text.len()
100    //         );
101    //     }
102
103    //     if is_current_user {
104    //         self.region_ranges.push(range.clone());
105    //         self.regions.push(RenderedRegion {
106    //             background_kind: Some(BackgroundKind::Mention),
107    //             link_url: None,
108    //         });
109    //     }
110    //     self.highlights
111    //         .push((range, Highlight::Highlight(mention_style)));
112    //     Ok(())
113    // }
114}
115
116pub fn render_markdown_mut(
117    block: &str,
118    mut mentions: &[Mention],
119    language_registry: &Arc<LanguageRegistry>,
120    language: Option<&Arc<Language>>,
121    text: &mut String,
122    highlights: &mut Vec<(Range<usize>, Highlight)>,
123    link_ranges: &mut Vec<Range<usize>>,
124    link_urls: &mut Vec<String>,
125) {
126    use pulldown_cmark::{CodeBlockKind, Event, Options, Parser, Tag};
127
128    let mut bold_depth = 0;
129    let mut italic_depth = 0;
130    let mut link_url = None;
131    let mut current_language = None;
132    let mut list_stack = Vec::new();
133
134    let options = Options::all();
135    for (event, source_range) in Parser::new_ext(&block, options).into_offset_iter() {
136        let prev_len = text.len();
137        match event {
138            Event::Text(t) => {
139                if let Some(language) = &current_language {
140                    render_code(text, highlights, t.as_ref(), language);
141                } else {
142                    while let Some(mention) = mentions.first() {
143                        if !source_range.contains_inclusive(&mention.range) {
144                            break;
145                        }
146                        mentions = &mentions[1..];
147                        let range = (prev_len + mention.range.start - source_range.start)
148                            ..(prev_len + mention.range.end - source_range.start);
149                        highlights.push((
150                            range.clone(),
151                            if mention.is_self_mention {
152                                Highlight::SelfMention
153                            } else {
154                                Highlight::Mention
155                            },
156                        ));
157                    }
158
159                    text.push_str(t.as_ref());
160                    let mut style = HighlightStyle::default();
161                    if bold_depth > 0 {
162                        style.font_weight = Some(FontWeight::BOLD);
163                    }
164                    if italic_depth > 0 {
165                        style.font_style = Some(FontStyle::Italic);
166                    }
167                    if let Some(link_url) = link_url.clone() {
168                        link_ranges.push(prev_len..text.len());
169                        link_urls.push(link_url);
170                        style.underline = Some(UnderlineStyle {
171                            thickness: 1.0.into(),
172                            ..Default::default()
173                        });
174                    }
175
176                    if style != HighlightStyle::default() {
177                        let mut new_highlight = true;
178                        if let Some((last_range, last_style)) = highlights.last_mut() {
179                            if last_range.end == prev_len
180                                && last_style == &Highlight::Highlight(style)
181                            {
182                                last_range.end = text.len();
183                                new_highlight = false;
184                            }
185                        }
186                        if new_highlight {
187                            highlights.push((prev_len..text.len(), Highlight::Highlight(style)));
188                        }
189                    }
190                }
191            }
192            Event::Code(t) => {
193                text.push_str(t.as_ref());
194                if link_url.is_some() {
195                    highlights.push((
196                        prev_len..text.len(),
197                        Highlight::Highlight(HighlightStyle {
198                            underline: Some(UnderlineStyle {
199                                thickness: 1.0.into(),
200                                ..Default::default()
201                            }),
202                            ..Default::default()
203                        }),
204                    ));
205                }
206                if let Some(link_url) = link_url.clone() {
207                    link_ranges.push(prev_len..text.len());
208                    link_urls.push(link_url);
209                }
210            }
211            Event::Start(tag) => match tag {
212                Tag::Paragraph => new_paragraph(text, &mut list_stack),
213                Tag::Heading(_, _, _) => {
214                    new_paragraph(text, &mut list_stack);
215                    bold_depth += 1;
216                }
217                Tag::CodeBlock(kind) => {
218                    new_paragraph(text, &mut list_stack);
219                    current_language = if let CodeBlockKind::Fenced(language) = kind {
220                        language_registry
221                            .language_for_name(language.as_ref())
222                            .now_or_never()
223                            .and_then(Result::ok)
224                    } else {
225                        language.cloned()
226                    }
227                }
228                Tag::Emphasis => italic_depth += 1,
229                Tag::Strong => bold_depth += 1,
230                Tag::Link(_, url, _) => link_url = Some(url.to_string()),
231                Tag::List(number) => {
232                    list_stack.push((number, false));
233                }
234                Tag::Item => {
235                    let len = list_stack.len();
236                    if let Some((list_number, has_content)) = list_stack.last_mut() {
237                        *has_content = false;
238                        if !text.is_empty() && !text.ends_with('\n') {
239                            text.push('\n');
240                        }
241                        for _ in 0..len - 1 {
242                            text.push_str("  ");
243                        }
244                        if let Some(number) = list_number {
245                            text.push_str(&format!("{}. ", number));
246                            *number += 1;
247                            *has_content = false;
248                        } else {
249                            text.push_str("- ");
250                        }
251                    }
252                }
253                _ => {}
254            },
255            Event::End(tag) => match tag {
256                Tag::Heading(_, _, _) => bold_depth -= 1,
257                Tag::CodeBlock(_) => current_language = None,
258                Tag::Emphasis => italic_depth -= 1,
259                Tag::Strong => bold_depth -= 1,
260                Tag::Link(_, _, _) => link_url = None,
261                Tag::List(_) => drop(list_stack.pop()),
262                _ => {}
263            },
264            Event::HardBreak => text.push('\n'),
265            Event::SoftBreak => text.push(' '),
266            _ => {}
267        }
268    }
269}
270
271pub fn render_markdown(
272    block: String,
273    mentions: &[Mention],
274    language_registry: &Arc<LanguageRegistry>,
275    language: Option<&Arc<Language>>,
276) -> RichText {
277    // let mut data = RichText {
278    //     text: Default::default(),
279    //     highlights: Default::default(),
280    //     region_ranges: Default::default(),
281    //     regions: Default::default(),
282    // };
283
284    let mut text = String::new();
285    let mut highlights = Vec::new();
286    let mut link_ranges = Vec::new();
287    let mut link_urls = Vec::new();
288    render_markdown_mut(
289        &block,
290        mentions,
291        language_registry,
292        language,
293        &mut text,
294        &mut highlights,
295        &mut link_ranges,
296        &mut link_urls,
297    );
298    text.truncate(text.trim_end().len());
299
300    RichText {
301        text: SharedString::from(text),
302        link_urls: link_urls.into(),
303        link_ranges,
304        highlights,
305    }
306}
307
308pub fn render_code(
309    text: &mut String,
310    highlights: &mut Vec<(Range<usize>, Highlight)>,
311    content: &str,
312    language: &Arc<Language>,
313) {
314    let prev_len = text.len();
315    text.push_str(content);
316    let mut offset = 0;
317    for (range, highlight_id) in language.highlight_text(&content.into(), 0..content.len()) {
318        if range.start > offset {
319            highlights.push((prev_len + offset..prev_len + range.start, Highlight::Code));
320        }
321        highlights.push((
322            prev_len + range.start..prev_len + range.end,
323            Highlight::Id(highlight_id),
324        ));
325        offset = range.end;
326    }
327    if offset < content.len() {
328        highlights.push((prev_len + offset..prev_len + content.len(), Highlight::Code));
329    }
330}
331
332pub fn new_paragraph(text: &mut String, list_stack: &mut Vec<(Option<u64>, bool)>) {
333    let mut is_subsequent_paragraph_of_list = false;
334    if let Some((_, has_content)) = list_stack.last_mut() {
335        if *has_content {
336            is_subsequent_paragraph_of_list = true;
337        } else {
338            *has_content = true;
339            return;
340        }
341    }
342
343    if !text.is_empty() {
344        if !text.ends_with('\n') {
345            text.push('\n');
346        }
347        text.push('\n');
348    }
349    for _ in 0..list_stack.len().saturating_sub(1) {
350        text.push_str("  ");
351    }
352    if is_subsequent_paragraph_of_list {
353        text.push_str("  ");
354    }
355}