rich_text.rs

  1use futures::FutureExt;
  2use gpui::{
  3    AnyElement, AnyView, ElementId, FontStyle, FontWeight, HighlightStyle, InteractiveText,
  4    IntoElement, SharedString, StrikethroughStyle, StyledText, UnderlineStyle, WindowContext,
  5};
  6use language::{HighlightId, Language, LanguageRegistry};
  7use std::{ops::Range, sync::Arc};
  8use theme::ActiveTheme;
  9use ui::LinkPreview;
 10use util::RangeExt;
 11
 12#[derive(Debug, Clone, PartialEq, Eq)]
 13pub enum Highlight {
 14    Code,
 15    Id(HighlightId),
 16    InlineCode(bool),
 17    Highlight(HighlightStyle),
 18    Mention,
 19    SelfMention,
 20}
 21
 22impl From<HighlightStyle> for Highlight {
 23    fn from(style: HighlightStyle) -> Self {
 24        Self::Highlight(style)
 25    }
 26}
 27
 28impl From<HighlightId> for Highlight {
 29    fn from(style: HighlightId) -> Self {
 30        Self::Id(style)
 31    }
 32}
 33
 34#[derive(Clone)]
 35pub struct RichText {
 36    pub text: SharedString,
 37    pub highlights: Vec<(Range<usize>, Highlight)>,
 38    pub link_ranges: Vec<Range<usize>>,
 39    pub link_urls: Arc<[String]>,
 40
 41    pub custom_ranges: Vec<Range<usize>>,
 42    custom_ranges_tooltip_fn:
 43        Option<Arc<dyn Fn(usize, Range<usize>, &mut WindowContext) -> Option<AnyView>>>,
 44}
 45
 46/// Allows one to specify extra links to the rendered markdown, which can be used
 47/// for e.g. mentions.
 48#[derive(Debug)]
 49pub struct Mention {
 50    pub range: Range<usize>,
 51    pub is_self_mention: bool,
 52}
 53
 54impl RichText {
 55    pub fn set_tooltip_builder_for_custom_ranges(
 56        &mut self,
 57        f: impl Fn(usize, Range<usize>, &mut WindowContext) -> Option<AnyView> + 'static,
 58    ) {
 59        self.custom_ranges_tooltip_fn = Some(Arc::new(f));
 60    }
 61
 62    pub fn element(&self, id: ElementId, cx: &mut WindowContext) -> AnyElement {
 63        let theme = cx.theme();
 64        let code_background = theme.colors().surface_background;
 65
 66        InteractiveText::new(
 67            id,
 68            StyledText::new(self.text.clone()).with_highlights(
 69                &cx.text_style(),
 70                self.highlights.iter().map(|(range, highlight)| {
 71                    (
 72                        range.clone(),
 73                        match highlight {
 74                            Highlight::Code => HighlightStyle {
 75                                background_color: Some(code_background),
 76                                ..Default::default()
 77                            },
 78                            Highlight::Id(id) => HighlightStyle {
 79                                background_color: Some(code_background),
 80                                ..id.style(theme.syntax()).unwrap_or_default()
 81                            },
 82                            Highlight::InlineCode(link) => {
 83                                if *link {
 84                                    HighlightStyle {
 85                                        background_color: Some(code_background),
 86                                        underline: Some(UnderlineStyle {
 87                                            thickness: 1.0.into(),
 88                                            ..Default::default()
 89                                        }),
 90                                        ..Default::default()
 91                                    }
 92                                } else {
 93                                    HighlightStyle {
 94                                        background_color: Some(code_background),
 95                                        ..Default::default()
 96                                    }
 97                                }
 98                            }
 99                            Highlight::Highlight(highlight) => *highlight,
100                            Highlight::Mention => HighlightStyle {
101                                font_weight: Some(FontWeight::BOLD),
102                                ..Default::default()
103                            },
104                            Highlight::SelfMention => HighlightStyle {
105                                font_weight: Some(FontWeight::BOLD),
106                                ..Default::default()
107                            },
108                        },
109                    )
110                }),
111            ),
112        )
113        .on_click(self.link_ranges.clone(), {
114            let link_urls = self.link_urls.clone();
115            move |ix, cx| {
116                let url = &link_urls[ix];
117                if url.starts_with("http") {
118                    cx.open_url(url);
119                }
120            }
121        })
122        .tooltip({
123            let link_ranges = self.link_ranges.clone();
124            let link_urls = self.link_urls.clone();
125            let custom_tooltip_ranges = self.custom_ranges.clone();
126            let custom_tooltip_fn = self.custom_ranges_tooltip_fn.clone();
127            move |idx, cx| {
128                for (ix, range) in link_ranges.iter().enumerate() {
129                    if range.contains(&idx) {
130                        return Some(LinkPreview::new(&link_urls[ix], cx));
131                    }
132                }
133                for range in &custom_tooltip_ranges {
134                    if range.contains(&idx) {
135                        if let Some(f) = &custom_tooltip_fn {
136                            return f(idx, range.clone(), cx);
137                        }
138                    }
139                }
140                None
141            }
142        })
143        .into_any_element()
144    }
145}
146
147#[allow(clippy::too_many_arguments)]
148pub fn render_markdown_mut(
149    block: &str,
150    mut mentions: &[Mention],
151    language_registry: &Arc<LanguageRegistry>,
152    language: Option<&Arc<Language>>,
153    text: &mut String,
154    highlights: &mut Vec<(Range<usize>, Highlight)>,
155    link_ranges: &mut Vec<Range<usize>>,
156    link_urls: &mut Vec<String>,
157) {
158    use pulldown_cmark::{CodeBlockKind, Event, Options, Parser, Tag, TagEnd};
159
160    let mut bold_depth = 0;
161    let mut italic_depth = 0;
162    let mut strikethrough_depth = 0;
163    let mut link_url = None;
164    let mut current_language = None;
165    let mut list_stack = Vec::new();
166
167    let options = Options::all();
168    for (event, source_range) in Parser::new_ext(block, options).into_offset_iter() {
169        let prev_len = text.len();
170        match event {
171            Event::Text(t) => {
172                if let Some(language) = &current_language {
173                    render_code(text, highlights, t.as_ref(), language);
174                } else {
175                    while let Some(mention) = mentions.first() {
176                        if !source_range.contains_inclusive(&mention.range) {
177                            break;
178                        }
179                        mentions = &mentions[1..];
180                        let range = (prev_len + mention.range.start - source_range.start)
181                            ..(prev_len + mention.range.end - source_range.start);
182                        highlights.push((
183                            range.clone(),
184                            if mention.is_self_mention {
185                                Highlight::SelfMention
186                            } else {
187                                Highlight::Mention
188                            },
189                        ));
190                    }
191
192                    text.push_str(t.as_ref());
193                    let mut style = HighlightStyle::default();
194                    if bold_depth > 0 {
195                        style.font_weight = Some(FontWeight::BOLD);
196                    }
197                    if italic_depth > 0 {
198                        style.font_style = Some(FontStyle::Italic);
199                    }
200                    if strikethrough_depth > 0 {
201                        style.strikethrough = Some(StrikethroughStyle {
202                            thickness: 1.0.into(),
203                            ..Default::default()
204                        });
205                    }
206                    let last_run_len = if let Some(link_url) = link_url.clone() {
207                        link_ranges.push(prev_len..text.len());
208                        link_urls.push(link_url);
209                        style.underline = Some(UnderlineStyle {
210                            thickness: 1.0.into(),
211                            ..Default::default()
212                        });
213                        prev_len
214                    } else {
215                        // Manually scan for links
216                        let mut finder = linkify::LinkFinder::new();
217                        finder.kinds(&[linkify::LinkKind::Url]);
218                        let mut last_link_len = prev_len;
219                        for link in finder.links(&t) {
220                            let start = link.start();
221                            let end = link.end();
222                            let range = (prev_len + start)..(prev_len + end);
223                            link_ranges.push(range.clone());
224                            link_urls.push(link.as_str().to_string());
225
226                            // If there is a style before we match a link, we have to add this to the highlighted ranges
227                            if style != HighlightStyle::default() && last_link_len < link.start() {
228                                highlights.push((
229                                    last_link_len..link.start(),
230                                    Highlight::Highlight(style),
231                                ));
232                            }
233
234                            highlights.push((
235                                range,
236                                Highlight::Highlight(HighlightStyle {
237                                    underline: Some(UnderlineStyle {
238                                        thickness: 1.0.into(),
239                                        ..Default::default()
240                                    }),
241                                    ..style
242                                }),
243                            ));
244
245                            last_link_len = end;
246                        }
247                        last_link_len
248                    };
249
250                    if style != HighlightStyle::default() && last_run_len < text.len() {
251                        let mut new_highlight = true;
252                        if let Some((last_range, last_style)) = highlights.last_mut() {
253                            if last_range.end == last_run_len
254                                && last_style == &Highlight::Highlight(style)
255                            {
256                                last_range.end = text.len();
257                                new_highlight = false;
258                            }
259                        }
260                        if new_highlight {
261                            highlights
262                                .push((last_run_len..text.len(), Highlight::Highlight(style)));
263                        }
264                    }
265                }
266            }
267            Event::Code(t) => {
268                text.push_str(t.as_ref());
269                let is_link = link_url.is_some();
270
271                if let Some(link_url) = link_url.clone() {
272                    link_ranges.push(prev_len..text.len());
273                    link_urls.push(link_url);
274                }
275
276                highlights.push((prev_len..text.len(), Highlight::InlineCode(is_link)))
277            }
278            Event::Start(tag) => match tag {
279                Tag::Paragraph => new_paragraph(text, &mut list_stack),
280                Tag::Heading {
281                    level: _,
282                    id: _,
283                    classes: _,
284                    attrs: _,
285                } => {
286                    new_paragraph(text, &mut list_stack);
287                    bold_depth += 1;
288                }
289                Tag::CodeBlock(kind) => {
290                    new_paragraph(text, &mut list_stack);
291                    current_language = if let CodeBlockKind::Fenced(language) = kind {
292                        language_registry
293                            .language_for_name(language.as_ref())
294                            .now_or_never()
295                            .and_then(Result::ok)
296                    } else {
297                        language.cloned()
298                    }
299                }
300                Tag::Emphasis => italic_depth += 1,
301                Tag::Strong => bold_depth += 1,
302                Tag::Strikethrough => strikethrough_depth += 1,
303                Tag::Link {
304                    link_type: _,
305                    dest_url,
306                    title: _,
307                    id: _,
308                } => link_url = Some(dest_url.to_string()),
309                Tag::List(number) => {
310                    list_stack.push((number, false));
311                }
312                Tag::Item => {
313                    let len = list_stack.len();
314                    if let Some((list_number, has_content)) = list_stack.last_mut() {
315                        *has_content = false;
316                        if !text.is_empty() && !text.ends_with('\n') {
317                            text.push('\n');
318                        }
319                        for _ in 0..len - 1 {
320                            text.push_str("  ");
321                        }
322                        if let Some(number) = list_number {
323                            text.push_str(&format!("{}. ", number));
324                            *number += 1;
325                            *has_content = false;
326                        } else {
327                            text.push_str("- ");
328                        }
329                    }
330                }
331                _ => {}
332            },
333            Event::End(tag) => match tag {
334                TagEnd::Heading(_) => bold_depth -= 1,
335                TagEnd::CodeBlock => current_language = None,
336                TagEnd::Emphasis => italic_depth -= 1,
337                TagEnd::Strong => bold_depth -= 1,
338                TagEnd::Strikethrough => strikethrough_depth -= 1,
339                TagEnd::Link => link_url = None,
340                TagEnd::List(_) => drop(list_stack.pop()),
341                _ => {}
342            },
343            Event::HardBreak => text.push('\n'),
344            Event::SoftBreak => text.push('\n'),
345            _ => {}
346        }
347    }
348}
349
350pub fn render_rich_text(
351    block: String,
352    mentions: &[Mention],
353    language_registry: &Arc<LanguageRegistry>,
354    language: Option<&Arc<Language>>,
355) -> RichText {
356    let mut text = String::new();
357    let mut highlights = Vec::new();
358    let mut link_ranges = Vec::new();
359    let mut link_urls = Vec::new();
360    render_markdown_mut(
361        &block,
362        mentions,
363        language_registry,
364        language,
365        &mut text,
366        &mut highlights,
367        &mut link_ranges,
368        &mut link_urls,
369    );
370    text.truncate(text.trim_end().len());
371
372    RichText {
373        text: SharedString::from(text),
374        link_urls: link_urls.into(),
375        link_ranges,
376        highlights,
377        custom_ranges: Vec::new(),
378        custom_ranges_tooltip_fn: None,
379    }
380}
381
382pub fn render_code(
383    text: &mut String,
384    highlights: &mut Vec<(Range<usize>, Highlight)>,
385    content: &str,
386    language: &Arc<Language>,
387) {
388    let prev_len = text.len();
389    text.push_str(content);
390    let mut offset = 0;
391    for (range, highlight_id) in language.highlight_text(&content.into(), 0..content.len()) {
392        if range.start > offset {
393            highlights.push((prev_len + offset..prev_len + range.start, Highlight::Code));
394        }
395        highlights.push((
396            prev_len + range.start..prev_len + range.end,
397            Highlight::Id(highlight_id),
398        ));
399        offset = range.end;
400    }
401    if offset < content.len() {
402        highlights.push((prev_len + offset..prev_len + content.len(), Highlight::Code));
403    }
404}
405
406pub fn new_paragraph(text: &mut String, list_stack: &mut Vec<(Option<u64>, bool)>) {
407    let mut is_subsequent_paragraph_of_list = false;
408    if let Some((_, has_content)) = list_stack.last_mut() {
409        if *has_content {
410            is_subsequent_paragraph_of_list = true;
411        } else {
412            *has_content = true;
413            return;
414        }
415    }
416
417    if !text.is_empty() {
418        if !text.ends_with('\n') {
419            text.push('\n');
420        }
421        text.push('\n');
422    }
423    for _ in 0..list_stack.len().saturating_sub(1) {
424        text.push_str("  ");
425    }
426    if is_subsequent_paragraph_of_list {
427        text.push_str("  ");
428    }
429}