1pub mod parser;
2
3use std::collections::{HashMap, HashSet};
4use std::iter;
5use std::mem;
6use std::ops::Range;
7use std::rc::Rc;
8use std::sync::Arc;
9
10use gpui::{
11 actions, point, quad, AnyElement, App, Bounds, ClipboardItem, CursorStyle, DispatchPhase,
12 Edges, Entity, FocusHandle, Focusable, FontStyle, FontWeight, GlobalElementId, Hitbox, Hsla,
13 KeyContext, Length, MouseDownEvent, MouseEvent, MouseMoveEvent, MouseUpEvent, Point, Render,
14 Stateful, StrikethroughStyle, StyleRefinement, StyledText, Task, TextLayout, TextRun,
15 TextStyle, TextStyleRefinement,
16};
17use language::{Language, LanguageRegistry, Rope};
18use parser::{parse_links_only, parse_markdown, MarkdownEvent, MarkdownTag, MarkdownTagEnd};
19use pulldown_cmark::Alignment;
20use theme::SyntaxTheme;
21use ui::{prelude::*, Tooltip};
22use util::{ResultExt, TryFutureExt};
23
24use crate::parser::CodeBlockKind;
25
26#[derive(Clone)]
27pub struct MarkdownStyle {
28 pub base_text_style: TextStyle,
29 pub code_block: StyleRefinement,
30 pub code_block_overflow_x_scroll: bool,
31 pub inline_code: TextStyleRefinement,
32 pub block_quote: TextStyleRefinement,
33 pub link: TextStyleRefinement,
34 pub rule_color: Hsla,
35 pub block_quote_border_color: Hsla,
36 pub syntax: Arc<SyntaxTheme>,
37 pub selection_background_color: Hsla,
38 pub heading: StyleRefinement,
39 pub table_overflow_x_scroll: bool,
40}
41
42impl Default for MarkdownStyle {
43 fn default() -> Self {
44 Self {
45 base_text_style: Default::default(),
46 code_block: Default::default(),
47 code_block_overflow_x_scroll: false,
48 inline_code: Default::default(),
49 block_quote: Default::default(),
50 link: Default::default(),
51 rule_color: Default::default(),
52 block_quote_border_color: Default::default(),
53 syntax: Arc::new(SyntaxTheme::default()),
54 selection_background_color: Default::default(),
55 heading: Default::default(),
56 table_overflow_x_scroll: false,
57 }
58 }
59}
60
61pub struct Markdown {
62 source: SharedString,
63 selection: Selection,
64 pressed_link: Option<RenderedLink>,
65 autoscroll_request: Option<usize>,
66 style: MarkdownStyle,
67 parsed_markdown: ParsedMarkdown,
68 should_reparse: bool,
69 pending_parse: Option<Task<Option<()>>>,
70 focus_handle: FocusHandle,
71 language_registry: Option<Arc<LanguageRegistry>>,
72 fallback_code_block_language: Option<String>,
73 open_url: Option<Box<dyn Fn(SharedString, &mut Window, &mut App)>>,
74 options: Options,
75 copied_code_blocks: HashSet<ElementId>,
76}
77
78#[derive(Debug)]
79struct Options {
80 parse_links_only: bool,
81 copy_code_block_buttons: bool,
82}
83
84actions!(markdown, [Copy]);
85
86impl Markdown {
87 pub fn new(
88 source: SharedString,
89 style: MarkdownStyle,
90 language_registry: Option<Arc<LanguageRegistry>>,
91 fallback_code_block_language: Option<String>,
92 cx: &mut Context<Self>,
93 ) -> Self {
94 let focus_handle = cx.focus_handle();
95 let mut this = Self {
96 source,
97 selection: Selection::default(),
98 pressed_link: None,
99 autoscroll_request: None,
100 style,
101 should_reparse: false,
102 parsed_markdown: ParsedMarkdown::default(),
103 pending_parse: None,
104 focus_handle,
105 language_registry,
106 fallback_code_block_language,
107 options: Options {
108 parse_links_only: false,
109 copy_code_block_buttons: true,
110 },
111 open_url: None,
112 copied_code_blocks: HashSet::new(),
113 };
114 this.parse(cx);
115 this
116 }
117
118 pub fn open_url(
119 self,
120 open_url: impl Fn(SharedString, &mut Window, &mut App) + 'static,
121 ) -> Self {
122 Self {
123 open_url: Some(Box::new(open_url)),
124 ..self
125 }
126 }
127
128 pub fn new_text(source: SharedString, style: MarkdownStyle, cx: &mut Context<Self>) -> Self {
129 let focus_handle = cx.focus_handle();
130 let mut this = Self {
131 source,
132 selection: Selection::default(),
133 pressed_link: None,
134 autoscroll_request: None,
135 style,
136 should_reparse: false,
137 parsed_markdown: ParsedMarkdown::default(),
138 pending_parse: None,
139 focus_handle,
140 language_registry: None,
141 fallback_code_block_language: None,
142 options: Options {
143 parse_links_only: true,
144 copy_code_block_buttons: true,
145 },
146 open_url: None,
147 copied_code_blocks: HashSet::new(),
148 };
149 this.parse(cx);
150 this
151 }
152
153 pub fn source(&self) -> &str {
154 &self.source
155 }
156
157 pub fn append(&mut self, text: &str, cx: &mut Context<Self>) {
158 self.source = SharedString::new(self.source.to_string() + text);
159 self.parse(cx);
160 }
161
162 pub fn reset(&mut self, source: SharedString, cx: &mut Context<Self>) {
163 if source == self.source() {
164 return;
165 }
166 self.source = source;
167 self.selection = Selection::default();
168 self.autoscroll_request = None;
169 self.pending_parse = None;
170 self.should_reparse = false;
171 self.parsed_markdown = ParsedMarkdown::default();
172 self.parse(cx);
173 }
174
175 pub fn parsed_markdown(&self) -> &ParsedMarkdown {
176 &self.parsed_markdown
177 }
178
179 fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
180 if self.selection.end <= self.selection.start {
181 return;
182 }
183 let text = text.text_for_range(self.selection.start..self.selection.end);
184 cx.write_to_clipboard(ClipboardItem::new_string(text));
185 }
186
187 fn parse(&mut self, cx: &mut Context<Self>) {
188 if self.source.is_empty() {
189 return;
190 }
191
192 if self.pending_parse.is_some() {
193 self.should_reparse = true;
194 return;
195 }
196
197 let source = self.source.clone();
198 let parse_text_only = self.options.parse_links_only;
199 let language_registry = self.language_registry.clone();
200 let fallback = self.fallback_code_block_language.clone();
201 let parsed = cx.background_spawn(async move {
202 if parse_text_only {
203 return anyhow::Ok(ParsedMarkdown {
204 events: Arc::from(parse_links_only(source.as_ref())),
205 source,
206 languages: HashMap::default(),
207 });
208 }
209 let (events, language_names) = parse_markdown(&source);
210 let mut languages = HashMap::with_capacity(language_names.len());
211 for name in language_names {
212 if let Some(registry) = language_registry.as_ref() {
213 let language = if !name.is_empty() {
214 registry.language_for_name(&name)
215 } else if let Some(fallback) = &fallback {
216 registry.language_for_name(fallback)
217 } else {
218 continue;
219 };
220 if let Ok(language) = language.await {
221 languages.insert(name, language);
222 }
223 }
224 }
225 anyhow::Ok(ParsedMarkdown {
226 source,
227 events: Arc::from(events),
228 languages,
229 })
230 });
231
232 self.should_reparse = false;
233 self.pending_parse = Some(cx.spawn(|this, mut cx| {
234 async move {
235 let parsed = parsed.await?;
236 this.update(&mut cx, |this, cx| {
237 this.parsed_markdown = parsed;
238 this.pending_parse.take();
239 if this.should_reparse {
240 this.parse(cx);
241 }
242 cx.notify();
243 })
244 .ok();
245 anyhow::Ok(())
246 }
247 .log_err()
248 }));
249 }
250
251 pub fn copy_code_block_buttons(mut self, should_copy: bool) -> Self {
252 self.options.copy_code_block_buttons = should_copy;
253 self
254 }
255}
256
257impl Render for Markdown {
258 fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
259 MarkdownElement::new(cx.entity().clone(), self.style.clone())
260 }
261}
262
263impl Focusable for Markdown {
264 fn focus_handle(&self, _cx: &App) -> FocusHandle {
265 self.focus_handle.clone()
266 }
267}
268
269#[derive(Copy, Clone, Default, Debug)]
270struct Selection {
271 start: usize,
272 end: usize,
273 reversed: bool,
274 pending: bool,
275}
276
277impl Selection {
278 fn set_head(&mut self, head: usize) {
279 if head < self.tail() {
280 if !self.reversed {
281 self.end = self.start;
282 self.reversed = true;
283 }
284 self.start = head;
285 } else {
286 if self.reversed {
287 self.start = self.end;
288 self.reversed = false;
289 }
290 self.end = head;
291 }
292 }
293
294 fn tail(&self) -> usize {
295 if self.reversed {
296 self.end
297 } else {
298 self.start
299 }
300 }
301}
302
303#[derive(Default)]
304pub struct ParsedMarkdown {
305 source: SharedString,
306 events: Arc<[(Range<usize>, MarkdownEvent)]>,
307 languages: HashMap<SharedString, Arc<Language>>,
308}
309
310impl ParsedMarkdown {
311 pub fn source(&self) -> &SharedString {
312 &self.source
313 }
314
315 pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
316 &self.events
317 }
318}
319
320pub struct MarkdownElement {
321 markdown: Entity<Markdown>,
322 style: MarkdownStyle,
323}
324
325impl MarkdownElement {
326 fn new(markdown: Entity<Markdown>, style: MarkdownStyle) -> Self {
327 Self { markdown, style }
328 }
329
330 fn paint_selection(
331 &self,
332 bounds: Bounds<Pixels>,
333 rendered_text: &RenderedText,
334 window: &mut Window,
335 cx: &mut App,
336 ) {
337 let selection = self.markdown.read(cx).selection;
338 let selection_start = rendered_text.position_for_source_index(selection.start);
339 let selection_end = rendered_text.position_for_source_index(selection.end);
340
341 if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
342 selection_start.zip(selection_end)
343 {
344 if start_position.y == end_position.y {
345 window.paint_quad(quad(
346 Bounds::from_corners(
347 start_position,
348 point(end_position.x, end_position.y + end_line_height),
349 ),
350 Pixels::ZERO,
351 self.style.selection_background_color,
352 Edges::default(),
353 Hsla::transparent_black(),
354 ));
355 } else {
356 window.paint_quad(quad(
357 Bounds::from_corners(
358 start_position,
359 point(bounds.right(), start_position.y + start_line_height),
360 ),
361 Pixels::ZERO,
362 self.style.selection_background_color,
363 Edges::default(),
364 Hsla::transparent_black(),
365 ));
366
367 if end_position.y > start_position.y + start_line_height {
368 window.paint_quad(quad(
369 Bounds::from_corners(
370 point(bounds.left(), start_position.y + start_line_height),
371 point(bounds.right(), end_position.y),
372 ),
373 Pixels::ZERO,
374 self.style.selection_background_color,
375 Edges::default(),
376 Hsla::transparent_black(),
377 ));
378 }
379
380 window.paint_quad(quad(
381 Bounds::from_corners(
382 point(bounds.left(), end_position.y),
383 point(end_position.x, end_position.y + end_line_height),
384 ),
385 Pixels::ZERO,
386 self.style.selection_background_color,
387 Edges::default(),
388 Hsla::transparent_black(),
389 ));
390 }
391 }
392 }
393
394 fn paint_mouse_listeners(
395 &self,
396 hitbox: &Hitbox,
397 rendered_text: &RenderedText,
398 window: &mut Window,
399 cx: &mut App,
400 ) {
401 let is_hovering_link = hitbox.is_hovered(window)
402 && !self.markdown.read(cx).selection.pending
403 && rendered_text
404 .link_for_position(window.mouse_position())
405 .is_some();
406
407 if is_hovering_link {
408 window.set_cursor_style(CursorStyle::PointingHand, hitbox);
409 } else {
410 window.set_cursor_style(CursorStyle::IBeam, hitbox);
411 }
412
413 self.on_mouse_event(window, cx, {
414 let rendered_text = rendered_text.clone();
415 let hitbox = hitbox.clone();
416 move |markdown, event: &MouseDownEvent, phase, window, cx| {
417 if hitbox.is_hovered(window) {
418 if phase.bubble() {
419 if let Some(link) = rendered_text.link_for_position(event.position) {
420 markdown.pressed_link = Some(link.clone());
421 } else {
422 let source_index =
423 match rendered_text.source_index_for_position(event.position) {
424 Ok(ix) | Err(ix) => ix,
425 };
426 let range = if event.click_count == 2 {
427 rendered_text.surrounding_word_range(source_index)
428 } else if event.click_count == 3 {
429 rendered_text.surrounding_line_range(source_index)
430 } else {
431 source_index..source_index
432 };
433 markdown.selection = Selection {
434 start: range.start,
435 end: range.end,
436 reversed: false,
437 pending: true,
438 };
439 window.focus(&markdown.focus_handle);
440 window.prevent_default();
441 }
442
443 cx.notify();
444 }
445 } else if phase.capture() {
446 markdown.selection = Selection::default();
447 markdown.pressed_link = None;
448 cx.notify();
449 }
450 }
451 });
452 self.on_mouse_event(window, cx, {
453 let rendered_text = rendered_text.clone();
454 let hitbox = hitbox.clone();
455 let was_hovering_link = is_hovering_link;
456 move |markdown, event: &MouseMoveEvent, phase, window, cx| {
457 if phase.capture() {
458 return;
459 }
460
461 if markdown.selection.pending {
462 let source_index = match rendered_text.source_index_for_position(event.position)
463 {
464 Ok(ix) | Err(ix) => ix,
465 };
466 markdown.selection.set_head(source_index);
467 markdown.autoscroll_request = Some(source_index);
468 cx.notify();
469 } else {
470 let is_hovering_link = hitbox.is_hovered(window)
471 && rendered_text.link_for_position(event.position).is_some();
472 if is_hovering_link != was_hovering_link {
473 cx.notify();
474 }
475 }
476 }
477 });
478 self.on_mouse_event(window, cx, {
479 let rendered_text = rendered_text.clone();
480 move |markdown, event: &MouseUpEvent, phase, window, cx| {
481 if phase.bubble() {
482 if let Some(pressed_link) = markdown.pressed_link.take() {
483 if Some(&pressed_link) == rendered_text.link_for_position(event.position) {
484 if let Some(open_url) = markdown.open_url.as_mut() {
485 open_url(pressed_link.destination_url, window, cx);
486 } else {
487 cx.open_url(&pressed_link.destination_url);
488 }
489 }
490 }
491 } else if markdown.selection.pending {
492 markdown.selection.pending = false;
493 #[cfg(any(target_os = "linux", target_os = "freebsd"))]
494 {
495 let text = rendered_text
496 .text_for_range(markdown.selection.start..markdown.selection.end);
497 cx.write_to_primary(ClipboardItem::new_string(text))
498 }
499 cx.notify();
500 }
501 }
502 });
503 }
504
505 fn autoscroll(
506 &self,
507 rendered_text: &RenderedText,
508 window: &mut Window,
509 cx: &mut App,
510 ) -> Option<()> {
511 let autoscroll_index = self
512 .markdown
513 .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
514 let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
515
516 let text_style = self.style.base_text_style.clone();
517 let font_id = window.text_system().resolve_font(&text_style.font());
518 let font_size = text_style.font_size.to_pixels(window.rem_size());
519 let em_width = window.text_system().em_width(font_id, font_size).unwrap();
520 window.request_autoscroll(Bounds::from_corners(
521 point(position.x - 3. * em_width, position.y - 3. * line_height),
522 point(position.x + 3. * em_width, position.y + 3. * line_height),
523 ));
524 Some(())
525 }
526
527 fn on_mouse_event<T: MouseEvent>(
528 &self,
529 window: &mut Window,
530 _cx: &mut App,
531 mut f: impl 'static
532 + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
533 ) {
534 window.on_mouse_event({
535 let markdown = self.markdown.downgrade();
536 move |event, phase, window, cx| {
537 markdown
538 .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
539 .log_err();
540 }
541 });
542 }
543}
544
545impl Element for MarkdownElement {
546 type RequestLayoutState = RenderedMarkdown;
547 type PrepaintState = Hitbox;
548
549 fn id(&self) -> Option<ElementId> {
550 None
551 }
552
553 fn request_layout(
554 &mut self,
555 _id: Option<&GlobalElementId>,
556 window: &mut Window,
557 cx: &mut App,
558 ) -> (gpui::LayoutId, Self::RequestLayoutState) {
559 let mut builder = MarkdownElementBuilder::new(
560 self.style.base_text_style.clone(),
561 self.style.syntax.clone(),
562 );
563 let parsed_markdown = &self.markdown.read(cx).parsed_markdown;
564 let markdown_end = if let Some(last) = parsed_markdown.events.last() {
565 last.0.end
566 } else {
567 0
568 };
569 for (range, event) in parsed_markdown.events.iter() {
570 match event {
571 MarkdownEvent::Start(tag) => {
572 match tag {
573 MarkdownTag::Paragraph => {
574 builder.push_div(
575 div().mb_2().line_height(rems(1.3)),
576 range,
577 markdown_end,
578 );
579 }
580 MarkdownTag::Heading { level, .. } => {
581 let mut heading = div().mb_2();
582 heading = match level {
583 pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
584 pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
585 pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
586 pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
587 _ => heading,
588 };
589 heading.style().refine(&self.style.heading);
590 builder.push_text_style(
591 self.style.heading.text_style().clone().unwrap_or_default(),
592 );
593 builder.push_div(heading, range, markdown_end);
594 }
595 MarkdownTag::BlockQuote => {
596 builder.push_text_style(self.style.block_quote.clone());
597 builder.push_div(
598 div()
599 .pl_4()
600 .mb_2()
601 .border_l_4()
602 .border_color(self.style.block_quote_border_color),
603 range,
604 markdown_end,
605 );
606 }
607 MarkdownTag::CodeBlock(kind) => {
608 let language = if let CodeBlockKind::Fenced(language) = kind {
609 parsed_markdown.languages.get(language).cloned()
610 } else {
611 None
612 };
613
614 let mut code_block = div()
615 .id(("code-block", range.start))
616 .flex()
617 .rounded_lg()
618 .when(self.style.code_block_overflow_x_scroll, |mut code_block| {
619 code_block.style().restrict_scroll_to_axis = Some(true);
620 code_block.overflow_x_scroll()
621 });
622 code_block.style().refine(&self.style.code_block);
623 if let Some(code_block_text_style) = &self.style.code_block.text {
624 builder.push_text_style(code_block_text_style.to_owned());
625 }
626 builder.push_code_block(language);
627 builder.push_div(code_block, range, markdown_end);
628 }
629 MarkdownTag::HtmlBlock => builder.push_div(div(), range, markdown_end),
630 MarkdownTag::List(bullet_index) => {
631 builder.push_list(*bullet_index);
632 builder.push_div(div().pl_4(), range, markdown_end);
633 }
634 MarkdownTag::Item => {
635 let bullet = if let Some(bullet_index) = builder.next_bullet_index() {
636 format!("{}.", bullet_index)
637 } else {
638 "•".to_string()
639 };
640 builder.push_div(
641 div()
642 .mb_1()
643 .h_flex()
644 .items_start()
645 .gap_1()
646 .line_height(rems(1.3))
647 .child(bullet),
648 range,
649 markdown_end,
650 );
651 // Without `w_0`, text doesn't wrap to the width of the container.
652 builder.push_div(div().flex_1().w_0(), range, markdown_end);
653 }
654 MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
655 font_style: Some(FontStyle::Italic),
656 ..Default::default()
657 }),
658 MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
659 font_weight: Some(FontWeight::BOLD),
660 ..Default::default()
661 }),
662 MarkdownTag::Strikethrough => {
663 builder.push_text_style(TextStyleRefinement {
664 strikethrough: Some(StrikethroughStyle {
665 thickness: px(1.),
666 color: None,
667 }),
668 ..Default::default()
669 })
670 }
671 MarkdownTag::Link { dest_url, .. } => {
672 if builder.code_block_stack.is_empty() {
673 builder.push_link(dest_url.clone(), range.clone());
674 builder.push_text_style(self.style.link.clone())
675 }
676 }
677 MarkdownTag::MetadataBlock(_) => {}
678 MarkdownTag::Table(alignments) => {
679 builder.table_alignments = alignments.clone();
680 builder.push_div(
681 div()
682 .id(("table", range.start))
683 .flex()
684 .border_1()
685 .border_color(cx.theme().colors().border)
686 .rounded_md()
687 .when(self.style.table_overflow_x_scroll, |mut table| {
688 table.style().restrict_scroll_to_axis = Some(true);
689 table.overflow_x_scroll()
690 }),
691 range,
692 markdown_end,
693 );
694 // This inner `v_flex` is so the table rows will stack vertically without disrupting the `overflow_x_scroll`.
695 builder.push_div(div().v_flex().flex_grow(), range, markdown_end);
696 }
697 MarkdownTag::TableHead => {
698 builder.push_div(
699 div()
700 .flex()
701 .justify_between()
702 .border_b_1()
703 .border_color(cx.theme().colors().border),
704 range,
705 markdown_end,
706 );
707 builder.push_text_style(TextStyleRefinement {
708 font_weight: Some(FontWeight::BOLD),
709 ..Default::default()
710 });
711 }
712 MarkdownTag::TableRow => {
713 builder.push_div(
714 div().h_flex().justify_between().px_1().py_0p5(),
715 range,
716 markdown_end,
717 );
718 }
719 MarkdownTag::TableCell => {
720 let column_count = builder.table_alignments.len();
721
722 builder.push_div(
723 div()
724 .flex()
725 .px_1()
726 .w(relative(1. / column_count as f32))
727 .truncate(),
728 range,
729 markdown_end,
730 );
731 }
732 _ => log::error!("unsupported markdown tag {:?}", tag),
733 }
734 }
735 MarkdownEvent::End(tag) => match tag {
736 MarkdownTagEnd::Paragraph => {
737 builder.pop_div();
738 }
739 MarkdownTagEnd::Heading(_) => {
740 builder.pop_div();
741 builder.pop_text_style()
742 }
743 MarkdownTagEnd::BlockQuote(_kind) => {
744 builder.pop_text_style();
745 builder.pop_div()
746 }
747 MarkdownTagEnd::CodeBlock => {
748 builder.trim_trailing_newline();
749
750 if self.markdown.read(cx).options.copy_code_block_buttons {
751 builder.flush_text();
752 builder.modify_current_div(|el| {
753 let id =
754 ElementId::NamedInteger("copy-markdown-code".into(), range.end);
755 let was_copied =
756 self.markdown.read(cx).copied_code_blocks.contains(&id);
757 let copy_button = div().absolute().top_1().right_1().w_5().child(
758 IconButton::new(
759 id.clone(),
760 if was_copied {
761 IconName::Check
762 } else {
763 IconName::Copy
764 },
765 )
766 .icon_color(Color::Muted)
767 .shape(ui::IconButtonShape::Square)
768 .tooltip(Tooltip::text("Copy Code"))
769 .on_click({
770 let id = id.clone();
771 let markdown = self.markdown.clone();
772 let code = without_fences(
773 parsed_markdown.source()[range.clone()].trim(),
774 )
775 .to_string();
776 move |_event, _window, cx| {
777 markdown.update(cx, |this, cx| {
778 this.copied_code_blocks.insert(id.clone());
779
780 cx.write_to_clipboard(ClipboardItem::new_string(
781 code.clone(),
782 ));
783 });
784 }
785 }),
786 );
787
788 el.child(copy_button)
789 });
790 }
791
792 builder.pop_div();
793 builder.pop_code_block();
794 if self.style.code_block.text.is_some() {
795 builder.pop_text_style();
796 }
797 }
798 MarkdownTagEnd::HtmlBlock => builder.pop_div(),
799 MarkdownTagEnd::List(_) => {
800 builder.pop_list();
801 builder.pop_div();
802 }
803 MarkdownTagEnd::Item => {
804 builder.pop_div();
805 builder.pop_div();
806 }
807 MarkdownTagEnd::Emphasis => builder.pop_text_style(),
808 MarkdownTagEnd::Strong => builder.pop_text_style(),
809 MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
810 MarkdownTagEnd::Link => {
811 if builder.code_block_stack.is_empty() {
812 builder.pop_text_style()
813 }
814 }
815 MarkdownTagEnd::Table => {
816 builder.pop_div();
817 builder.pop_div();
818 builder.table_alignments.clear();
819 }
820 MarkdownTagEnd::TableHead => {
821 builder.pop_div();
822 builder.pop_text_style();
823 }
824 MarkdownTagEnd::TableRow => {
825 builder.pop_div();
826 }
827 MarkdownTagEnd::TableCell => {
828 builder.pop_div();
829 }
830 _ => log::error!("unsupported markdown tag end: {:?}", tag),
831 },
832 MarkdownEvent::Text(parsed) => {
833 builder.push_text(parsed, range.start);
834 }
835 MarkdownEvent::Code => {
836 builder.push_text_style(self.style.inline_code.clone());
837 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
838 builder.pop_text_style();
839 }
840 MarkdownEvent::Html => {
841 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
842 }
843 MarkdownEvent::InlineHtml => {
844 builder.push_text(&parsed_markdown.source[range.clone()], range.start);
845 }
846 MarkdownEvent::Rule => {
847 builder.push_div(
848 div()
849 .border_b_1()
850 .my_2()
851 .border_color(self.style.rule_color),
852 range,
853 markdown_end,
854 );
855 builder.pop_div()
856 }
857 MarkdownEvent::SoftBreak => builder.push_text(" ", range.start),
858 MarkdownEvent::HardBreak => builder.push_text("\n", range.start),
859 _ => log::error!("unsupported markdown event {:?}", event),
860 }
861 }
862 let mut rendered_markdown = builder.build();
863 let child_layout_id = rendered_markdown.element.request_layout(window, cx);
864 let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
865 (layout_id, rendered_markdown)
866 }
867
868 fn prepaint(
869 &mut self,
870 _id: Option<&GlobalElementId>,
871 bounds: Bounds<Pixels>,
872 rendered_markdown: &mut Self::RequestLayoutState,
873 window: &mut Window,
874 cx: &mut App,
875 ) -> Self::PrepaintState {
876 let focus_handle = self.markdown.read(cx).focus_handle.clone();
877 window.set_focus_handle(&focus_handle, cx);
878
879 let hitbox = window.insert_hitbox(bounds, false);
880 rendered_markdown.element.prepaint(window, cx);
881 self.autoscroll(&rendered_markdown.text, window, cx);
882 hitbox
883 }
884
885 fn paint(
886 &mut self,
887 _id: Option<&GlobalElementId>,
888 bounds: Bounds<Pixels>,
889 rendered_markdown: &mut Self::RequestLayoutState,
890 hitbox: &mut Self::PrepaintState,
891 window: &mut Window,
892 cx: &mut App,
893 ) {
894 let mut context = KeyContext::default();
895 context.add("Markdown");
896 window.set_key_context(context);
897 let entity = self.markdown.clone();
898 window.on_action(std::any::TypeId::of::<crate::Copy>(), {
899 let text = rendered_markdown.text.clone();
900 move |_, phase, window, cx| {
901 let text = text.clone();
902 if phase == DispatchPhase::Bubble {
903 entity.update(cx, move |this, cx| this.copy(&text, window, cx))
904 }
905 }
906 });
907
908 self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
909 rendered_markdown.element.paint(window, cx);
910 self.paint_selection(bounds, &rendered_markdown.text, window, cx);
911 }
912}
913
914impl IntoElement for MarkdownElement {
915 type Element = Self;
916
917 fn into_element(self) -> Self::Element {
918 self
919 }
920}
921
922enum AnyDiv {
923 Div(Div),
924 Stateful(Stateful<Div>),
925}
926
927impl AnyDiv {
928 fn into_any_element(self) -> AnyElement {
929 match self {
930 Self::Div(div) => div.into_any_element(),
931 Self::Stateful(div) => div.into_any_element(),
932 }
933 }
934}
935
936impl From<Div> for AnyDiv {
937 fn from(value: Div) -> Self {
938 Self::Div(value)
939 }
940}
941
942impl From<Stateful<Div>> for AnyDiv {
943 fn from(value: Stateful<Div>) -> Self {
944 Self::Stateful(value)
945 }
946}
947
948impl Styled for AnyDiv {
949 fn style(&mut self) -> &mut StyleRefinement {
950 match self {
951 Self::Div(div) => div.style(),
952 Self::Stateful(div) => div.style(),
953 }
954 }
955}
956
957impl ParentElement for AnyDiv {
958 fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
959 match self {
960 Self::Div(div) => div.extend(elements),
961 Self::Stateful(div) => div.extend(elements),
962 }
963 }
964}
965
966struct MarkdownElementBuilder {
967 div_stack: Vec<AnyDiv>,
968 rendered_lines: Vec<RenderedLine>,
969 pending_line: PendingLine,
970 rendered_links: Vec<RenderedLink>,
971 current_source_index: usize,
972 base_text_style: TextStyle,
973 text_style_stack: Vec<TextStyleRefinement>,
974 code_block_stack: Vec<Option<Arc<Language>>>,
975 list_stack: Vec<ListStackEntry>,
976 table_alignments: Vec<Alignment>,
977 syntax_theme: Arc<SyntaxTheme>,
978}
979
980#[derive(Default)]
981struct PendingLine {
982 text: String,
983 runs: Vec<TextRun>,
984 source_mappings: Vec<SourceMapping>,
985}
986
987struct ListStackEntry {
988 bullet_index: Option<u64>,
989}
990
991impl MarkdownElementBuilder {
992 fn new(base_text_style: TextStyle, syntax_theme: Arc<SyntaxTheme>) -> Self {
993 Self {
994 div_stack: vec![div().debug_selector(|| "inner".into()).into()],
995 rendered_lines: Vec::new(),
996 pending_line: PendingLine::default(),
997 rendered_links: Vec::new(),
998 current_source_index: 0,
999 base_text_style,
1000 text_style_stack: Vec::new(),
1001 code_block_stack: Vec::new(),
1002 list_stack: Vec::new(),
1003 table_alignments: Vec::new(),
1004 syntax_theme,
1005 }
1006 }
1007
1008 fn push_text_style(&mut self, style: TextStyleRefinement) {
1009 self.text_style_stack.push(style);
1010 }
1011
1012 fn text_style(&self) -> TextStyle {
1013 let mut style = self.base_text_style.clone();
1014 for refinement in &self.text_style_stack {
1015 style.refine(refinement);
1016 }
1017 style
1018 }
1019
1020 fn pop_text_style(&mut self) {
1021 self.text_style_stack.pop();
1022 }
1023
1024 fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
1025 let mut div = div.into();
1026 self.flush_text();
1027
1028 if range.start == 0 {
1029 // Remove the top margin on the first element.
1030 div.style().refine(&StyleRefinement {
1031 margin: gpui::EdgesRefinement {
1032 top: Some(Length::Definite(px(0.).into())),
1033 left: None,
1034 right: None,
1035 bottom: None,
1036 },
1037 ..Default::default()
1038 });
1039 }
1040
1041 if range.end == markdown_end {
1042 div.style().refine(&StyleRefinement {
1043 margin: gpui::EdgesRefinement {
1044 top: None,
1045 left: None,
1046 right: None,
1047 bottom: Some(Length::Definite(rems(0.).into())),
1048 },
1049 ..Default::default()
1050 });
1051 }
1052
1053 self.div_stack.push(div);
1054 }
1055
1056 fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
1057 self.flush_text();
1058 if let Some(div) = self.div_stack.pop() {
1059 self.div_stack.push(f(div));
1060 }
1061 }
1062
1063 fn pop_div(&mut self) {
1064 self.flush_text();
1065 let div = self.div_stack.pop().unwrap().into_any_element();
1066 self.div_stack.last_mut().unwrap().extend(iter::once(div));
1067 }
1068
1069 fn push_list(&mut self, bullet_index: Option<u64>) {
1070 self.list_stack.push(ListStackEntry { bullet_index });
1071 }
1072
1073 fn next_bullet_index(&mut self) -> Option<u64> {
1074 self.list_stack.last_mut().and_then(|entry| {
1075 let item_index = entry.bullet_index.as_mut()?;
1076 *item_index += 1;
1077 Some(*item_index - 1)
1078 })
1079 }
1080
1081 fn pop_list(&mut self) {
1082 self.list_stack.pop();
1083 }
1084
1085 fn push_code_block(&mut self, language: Option<Arc<Language>>) {
1086 self.code_block_stack.push(language);
1087 }
1088
1089 fn pop_code_block(&mut self) {
1090 self.code_block_stack.pop();
1091 }
1092
1093 fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
1094 self.rendered_links.push(RenderedLink {
1095 source_range,
1096 destination_url,
1097 });
1098 }
1099
1100 fn push_text(&mut self, text: &str, source_index: usize) {
1101 self.pending_line.source_mappings.push(SourceMapping {
1102 rendered_index: self.pending_line.text.len(),
1103 source_index,
1104 });
1105 self.pending_line.text.push_str(text);
1106 self.current_source_index = source_index + text.len();
1107
1108 if let Some(Some(language)) = self.code_block_stack.last() {
1109 let mut offset = 0;
1110 for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
1111 if range.start > offset {
1112 self.pending_line
1113 .runs
1114 .push(self.text_style().to_run(range.start - offset));
1115 }
1116
1117 let mut run_style = self.text_style();
1118 if let Some(highlight) = highlight_id.style(&self.syntax_theme) {
1119 run_style = run_style.highlight(highlight);
1120 }
1121 self.pending_line.runs.push(run_style.to_run(range.len()));
1122 offset = range.end;
1123 }
1124
1125 if offset < text.len() {
1126 self.pending_line
1127 .runs
1128 .push(self.text_style().to_run(text.len() - offset));
1129 }
1130 } else {
1131 self.pending_line
1132 .runs
1133 .push(self.text_style().to_run(text.len()));
1134 }
1135 }
1136
1137 fn trim_trailing_newline(&mut self) {
1138 if self.pending_line.text.ends_with('\n') {
1139 self.pending_line
1140 .text
1141 .truncate(self.pending_line.text.len() - 1);
1142 self.pending_line.runs.last_mut().unwrap().len -= 1;
1143 self.current_source_index -= 1;
1144 }
1145 }
1146
1147 fn flush_text(&mut self) {
1148 let line = mem::take(&mut self.pending_line);
1149 if line.text.is_empty() {
1150 return;
1151 }
1152
1153 let text = StyledText::new(line.text).with_runs(line.runs);
1154 self.rendered_lines.push(RenderedLine {
1155 layout: text.layout().clone(),
1156 source_mappings: line.source_mappings,
1157 source_end: self.current_source_index,
1158 });
1159 self.div_stack.last_mut().unwrap().extend([text.into_any()]);
1160 }
1161
1162 fn build(mut self) -> RenderedMarkdown {
1163 debug_assert_eq!(self.div_stack.len(), 1);
1164 self.flush_text();
1165 RenderedMarkdown {
1166 element: self.div_stack.pop().unwrap().into_any_element(),
1167 text: RenderedText {
1168 lines: self.rendered_lines.into(),
1169 links: self.rendered_links.into(),
1170 },
1171 }
1172 }
1173}
1174
1175struct RenderedLine {
1176 layout: TextLayout,
1177 source_mappings: Vec<SourceMapping>,
1178 source_end: usize,
1179}
1180
1181impl RenderedLine {
1182 fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
1183 let mapping = match self
1184 .source_mappings
1185 .binary_search_by_key(&source_index, |probe| probe.source_index)
1186 {
1187 Ok(ix) => &self.source_mappings[ix],
1188 Err(ix) => &self.source_mappings[ix - 1],
1189 };
1190 mapping.rendered_index + (source_index - mapping.source_index)
1191 }
1192
1193 fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
1194 let mapping = match self
1195 .source_mappings
1196 .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
1197 {
1198 Ok(ix) => &self.source_mappings[ix],
1199 Err(ix) => &self.source_mappings[ix - 1],
1200 };
1201 mapping.source_index + (rendered_index - mapping.rendered_index)
1202 }
1203
1204 fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1205 let line_rendered_index;
1206 let out_of_bounds;
1207 match self.layout.index_for_position(position) {
1208 Ok(ix) => {
1209 line_rendered_index = ix;
1210 out_of_bounds = false;
1211 }
1212 Err(ix) => {
1213 line_rendered_index = ix;
1214 out_of_bounds = true;
1215 }
1216 };
1217 let source_index = self.source_index_for_rendered_index(line_rendered_index);
1218 if out_of_bounds {
1219 Err(source_index)
1220 } else {
1221 Ok(source_index)
1222 }
1223 }
1224}
1225
1226#[derive(Copy, Clone, Debug, Default)]
1227struct SourceMapping {
1228 rendered_index: usize,
1229 source_index: usize,
1230}
1231
1232pub struct RenderedMarkdown {
1233 element: AnyElement,
1234 text: RenderedText,
1235}
1236
1237#[derive(Clone)]
1238struct RenderedText {
1239 lines: Rc<[RenderedLine]>,
1240 links: Rc<[RenderedLink]>,
1241}
1242
1243#[derive(Clone, Eq, PartialEq)]
1244struct RenderedLink {
1245 source_range: Range<usize>,
1246 destination_url: SharedString,
1247}
1248
1249impl RenderedText {
1250 fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1251 let mut lines = self.lines.iter().peekable();
1252
1253 while let Some(line) = lines.next() {
1254 let line_bounds = line.layout.bounds();
1255 if position.y > line_bounds.bottom() {
1256 if let Some(next_line) = lines.peek() {
1257 if position.y < next_line.layout.bounds().top() {
1258 return Err(line.source_end);
1259 }
1260 }
1261
1262 continue;
1263 }
1264
1265 return line.source_index_for_position(position);
1266 }
1267
1268 Err(self.lines.last().map_or(0, |line| line.source_end))
1269 }
1270
1271 fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
1272 for line in self.lines.iter() {
1273 let line_source_start = line.source_mappings.first().unwrap().source_index;
1274 if source_index < line_source_start {
1275 break;
1276 } else if source_index > line.source_end {
1277 continue;
1278 } else {
1279 let line_height = line.layout.line_height();
1280 let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
1281 let position = line.layout.position_for_index(rendered_index_within_line)?;
1282 return Some((position, line_height));
1283 }
1284 }
1285 None
1286 }
1287
1288 fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
1289 for line in self.lines.iter() {
1290 if source_index > line.source_end {
1291 continue;
1292 }
1293
1294 let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
1295 let rendered_index_in_line =
1296 line.rendered_index_for_source_index(source_index) - line_rendered_start;
1297 let text = line.layout.text();
1298 let previous_space = if let Some(idx) = text[0..rendered_index_in_line].rfind(' ') {
1299 idx + ' '.len_utf8()
1300 } else {
1301 0
1302 };
1303 let next_space = if let Some(idx) = text[rendered_index_in_line..].find(' ') {
1304 rendered_index_in_line + idx
1305 } else {
1306 text.len()
1307 };
1308
1309 return line.source_index_for_rendered_index(line_rendered_start + previous_space)
1310 ..line.source_index_for_rendered_index(line_rendered_start + next_space);
1311 }
1312
1313 source_index..source_index
1314 }
1315
1316 fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
1317 for line in self.lines.iter() {
1318 if source_index > line.source_end {
1319 continue;
1320 }
1321 let line_source_start = line.source_mappings.first().unwrap().source_index;
1322 return line_source_start..line.source_end;
1323 }
1324
1325 source_index..source_index
1326 }
1327
1328 fn text_for_range(&self, range: Range<usize>) -> String {
1329 let mut ret = vec![];
1330
1331 for line in self.lines.iter() {
1332 if range.start > line.source_end {
1333 continue;
1334 }
1335 let line_source_start = line.source_mappings.first().unwrap().source_index;
1336 if range.end < line_source_start {
1337 break;
1338 }
1339
1340 let text = line.layout.text();
1341
1342 let start = if range.start < line_source_start {
1343 0
1344 } else {
1345 line.rendered_index_for_source_index(range.start)
1346 };
1347 let end = if range.end > line.source_end {
1348 line.rendered_index_for_source_index(line.source_end)
1349 } else {
1350 line.rendered_index_for_source_index(range.end)
1351 }
1352 .min(text.len());
1353
1354 ret.push(text[start..end].to_string());
1355 }
1356 ret.join("\n")
1357 }
1358
1359 fn link_for_position(&self, position: Point<Pixels>) -> Option<&RenderedLink> {
1360 let source_index = self.source_index_for_position(position).ok()?;
1361 self.links
1362 .iter()
1363 .find(|link| link.source_range.contains(&source_index))
1364 }
1365}
1366
1367/// Some markdown blocks are indented, and others have e.g. ```rust … ``` around them.
1368/// If this block is fenced with backticks, strip them off (and the language name).
1369/// We use this when copying code blocks to the clipboard.
1370fn without_fences(mut markdown: &str) -> &str {
1371 if let Some(opening_backticks) = markdown.find("```") {
1372 markdown = &markdown[opening_backticks..];
1373
1374 // Trim off the next newline. This also trims off a language name if it's there.
1375 if let Some(newline) = markdown.find('\n') {
1376 markdown = &markdown[newline + 1..];
1377 }
1378 };
1379
1380 if let Some(closing_backticks) = markdown.rfind("```") {
1381 markdown = &markdown[..closing_backticks];
1382 };
1383
1384 markdown
1385}
1386
1387#[cfg(test)]
1388mod tests {
1389 use super::*;
1390
1391 #[test]
1392 fn test_without_fences() {
1393 let input = "```rust\nlet x = 5;\n```";
1394 assert_eq!(without_fences(input), "let x = 5;\n");
1395
1396 let input = " ```\nno language\n``` ";
1397 assert_eq!(without_fences(input), "no language\n");
1398
1399 let input = "plain text";
1400 assert_eq!(without_fences(input), "plain text");
1401
1402 let input = "```python\nprint('hello')\nprint('world')\n```";
1403 assert_eq!(without_fences(input), "print('hello')\nprint('world')\n");
1404 }
1405}