markdown.rs

   1pub mod parser;
   2mod path_range;
   3
   4use base64::Engine as _;
   5use futures::FutureExt as _;
   6use gpui::HitboxBehavior;
   7use language::LanguageName;
   8use log::Level;
   9pub use path_range::{LineCol, PathWithRange};
  10use ui::Checkbox;
  11
  12use std::borrow::Cow;
  13use std::iter;
  14use std::mem;
  15use std::ops::Range;
  16use std::path::Path;
  17use std::rc::Rc;
  18use std::sync::Arc;
  19use std::time::Duration;
  20
  21use collections::{HashMap, HashSet};
  22use gpui::{
  23    AnyElement, App, BorderStyle, Bounds, ClipboardItem, CursorStyle, DispatchPhase, Edges, Entity,
  24    FocusHandle, Focusable, FontStyle, FontWeight, GlobalElementId, Hitbox, Hsla, Image,
  25    ImageFormat, KeyContext, Length, MouseDownEvent, MouseEvent, MouseMoveEvent, MouseUpEvent,
  26    Point, ScrollHandle, Stateful, StrikethroughStyle, StyleRefinement, StyledText, Task,
  27    TextLayout, TextRun, TextStyle, TextStyleRefinement, actions, img, point, quad,
  28};
  29use language::{Language, LanguageRegistry, Rope};
  30use parser::CodeBlockMetadata;
  31use parser::{MarkdownEvent, MarkdownTag, MarkdownTagEnd, parse_links_only, parse_markdown};
  32use pulldown_cmark::Alignment;
  33use sum_tree::TreeMap;
  34use theme::SyntaxTheme;
  35use ui::{ScrollAxes, Scrollbars, Tooltip, WithScrollbar, prelude::*};
  36use util::ResultExt;
  37
  38use crate::parser::CodeBlockKind;
  39
  40/// A callback function that can be used to customize the style of links based on the destination URL.
  41/// If the callback returns `None`, the default link style will be used.
  42type LinkStyleCallback = Rc<dyn Fn(&str, &App) -> Option<TextStyleRefinement>>;
  43
  44/// Defines custom style refinements for each heading level (H1-H6)
  45#[derive(Clone, Default)]
  46pub struct HeadingLevelStyles {
  47    pub h1: Option<TextStyleRefinement>,
  48    pub h2: Option<TextStyleRefinement>,
  49    pub h3: Option<TextStyleRefinement>,
  50    pub h4: Option<TextStyleRefinement>,
  51    pub h5: Option<TextStyleRefinement>,
  52    pub h6: Option<TextStyleRefinement>,
  53}
  54
  55#[derive(Clone)]
  56pub struct MarkdownStyle {
  57    pub base_text_style: TextStyle,
  58    pub container_style: StyleRefinement,
  59    pub code_block: StyleRefinement,
  60    pub code_block_overflow_x_scroll: bool,
  61    pub inline_code: TextStyleRefinement,
  62    pub block_quote: TextStyleRefinement,
  63    pub link: TextStyleRefinement,
  64    pub link_callback: Option<LinkStyleCallback>,
  65    pub rule_color: Hsla,
  66    pub block_quote_border_color: Hsla,
  67    pub syntax: Arc<SyntaxTheme>,
  68    pub selection_background_color: Hsla,
  69    pub heading: StyleRefinement,
  70    pub heading_level_styles: Option<HeadingLevelStyles>,
  71    pub height_is_multiple_of_line_height: bool,
  72    pub prevent_mouse_interaction: bool,
  73}
  74
  75impl Default for MarkdownStyle {
  76    fn default() -> Self {
  77        Self {
  78            base_text_style: Default::default(),
  79            container_style: Default::default(),
  80            code_block: Default::default(),
  81            code_block_overflow_x_scroll: false,
  82            inline_code: Default::default(),
  83            block_quote: Default::default(),
  84            link: Default::default(),
  85            link_callback: None,
  86            rule_color: Default::default(),
  87            block_quote_border_color: Default::default(),
  88            syntax: Arc::new(SyntaxTheme::default()),
  89            selection_background_color: Default::default(),
  90            heading: Default::default(),
  91            heading_level_styles: None,
  92            height_is_multiple_of_line_height: false,
  93            prevent_mouse_interaction: false,
  94        }
  95    }
  96}
  97
  98pub struct Markdown {
  99    source: SharedString,
 100    selection: Selection,
 101    pressed_link: Option<RenderedLink>,
 102    autoscroll_request: Option<usize>,
 103    parsed_markdown: ParsedMarkdown,
 104    images_by_source_offset: HashMap<usize, Arc<Image>>,
 105    should_reparse: bool,
 106    pending_parse: Option<Task<()>>,
 107    focus_handle: FocusHandle,
 108    language_registry: Option<Arc<LanguageRegistry>>,
 109    fallback_code_block_language: Option<LanguageName>,
 110    options: Options,
 111    copied_code_blocks: HashSet<ElementId>,
 112    code_block_scroll_handles: HashMap<usize, ScrollHandle>,
 113}
 114
 115struct Options {
 116    parse_links_only: bool,
 117}
 118
 119pub enum CodeBlockRenderer {
 120    Default {
 121        copy_button: bool,
 122        copy_button_on_hover: bool,
 123        border: bool,
 124    },
 125    Custom {
 126        render: CodeBlockRenderFn,
 127        /// A function that can modify the parent container after the code block
 128        /// content has been appended as a child element.
 129        transform: Option<CodeBlockTransformFn>,
 130    },
 131}
 132
 133pub type CodeBlockRenderFn = Arc<
 134    dyn Fn(
 135        &CodeBlockKind,
 136        &ParsedMarkdown,
 137        Range<usize>,
 138        CodeBlockMetadata,
 139        &mut Window,
 140        &App,
 141    ) -> Div,
 142>;
 143
 144pub type CodeBlockTransformFn =
 145    Arc<dyn Fn(AnyDiv, Range<usize>, CodeBlockMetadata, &mut Window, &App) -> AnyDiv>;
 146
 147actions!(
 148    markdown,
 149    [
 150        /// Copies the selected text to the clipboard.
 151        Copy,
 152    ]
 153);
 154
 155impl Markdown {
 156    pub fn new(
 157        source: SharedString,
 158        language_registry: Option<Arc<LanguageRegistry>>,
 159        fallback_code_block_language: Option<LanguageName>,
 160        cx: &mut Context<Self>,
 161    ) -> Self {
 162        let focus_handle = cx.focus_handle();
 163        let mut this = Self {
 164            source,
 165            selection: Selection::default(),
 166            pressed_link: None,
 167            autoscroll_request: None,
 168            should_reparse: false,
 169            images_by_source_offset: Default::default(),
 170            parsed_markdown: ParsedMarkdown::default(),
 171            pending_parse: None,
 172            focus_handle,
 173            language_registry,
 174            fallback_code_block_language,
 175            options: Options {
 176                parse_links_only: false,
 177            },
 178            copied_code_blocks: HashSet::default(),
 179            code_block_scroll_handles: HashMap::default(),
 180        };
 181        this.parse(cx);
 182        this
 183    }
 184
 185    pub fn new_text(source: SharedString, cx: &mut Context<Self>) -> Self {
 186        let focus_handle = cx.focus_handle();
 187        let mut this = Self {
 188            source,
 189            selection: Selection::default(),
 190            pressed_link: None,
 191            autoscroll_request: None,
 192            should_reparse: false,
 193            parsed_markdown: ParsedMarkdown::default(),
 194            images_by_source_offset: Default::default(),
 195            pending_parse: None,
 196            focus_handle,
 197            language_registry: None,
 198            fallback_code_block_language: None,
 199            options: Options {
 200                parse_links_only: true,
 201            },
 202            copied_code_blocks: HashSet::default(),
 203            code_block_scroll_handles: HashMap::default(),
 204        };
 205        this.parse(cx);
 206        this
 207    }
 208
 209    fn code_block_scroll_handle(&mut self, id: usize) -> ScrollHandle {
 210        self.code_block_scroll_handles
 211            .entry(id)
 212            .or_insert_with(ScrollHandle::new)
 213            .clone()
 214    }
 215
 216    fn retain_code_block_scroll_handles(&mut self, ids: &HashSet<usize>) {
 217        self.code_block_scroll_handles
 218            .retain(|id, _| ids.contains(id));
 219    }
 220
 221    fn clear_code_block_scroll_handles(&mut self) {
 222        self.code_block_scroll_handles.clear();
 223    }
 224
 225    pub fn is_parsing(&self) -> bool {
 226        self.pending_parse.is_some()
 227    }
 228
 229    pub fn source(&self) -> &str {
 230        &self.source
 231    }
 232
 233    pub fn append(&mut self, text: &str, cx: &mut Context<Self>) {
 234        self.source = SharedString::new(self.source.to_string() + text);
 235        self.parse(cx);
 236    }
 237
 238    pub fn replace(&mut self, source: impl Into<SharedString>, cx: &mut Context<Self>) {
 239        self.source = source.into();
 240        self.parse(cx);
 241    }
 242
 243    pub fn reset(&mut self, source: SharedString, cx: &mut Context<Self>) {
 244        if source == self.source() {
 245            return;
 246        }
 247        self.source = source;
 248        self.selection = Selection::default();
 249        self.autoscroll_request = None;
 250        self.pending_parse = None;
 251        self.should_reparse = false;
 252        // Don't clear parsed_markdown here - keep existing content visible until new parse completes
 253        self.parse(cx);
 254    }
 255
 256    #[cfg(any(test, feature = "test-support"))]
 257    pub fn parsed_markdown(&self) -> &ParsedMarkdown {
 258        &self.parsed_markdown
 259    }
 260
 261    pub fn escape(s: &str) -> Cow<'_, str> {
 262        // Valid to use bytes since multi-byte UTF-8 doesn't use ASCII chars.
 263        let count = s
 264            .bytes()
 265            .filter(|c| *c == b'\n' || c.is_ascii_punctuation())
 266            .count();
 267        if count > 0 {
 268            let mut output = String::with_capacity(s.len() + count);
 269            let mut is_newline = false;
 270            for c in s.chars() {
 271                if is_newline && c == ' ' {
 272                    continue;
 273                }
 274                is_newline = c == '\n';
 275                if c == '\n' {
 276                    output.push('\n')
 277                } else if c.is_ascii_punctuation() {
 278                    output.push('\\')
 279                }
 280                output.push(c)
 281            }
 282            output.into()
 283        } else {
 284            s.into()
 285        }
 286    }
 287
 288    fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
 289        if self.selection.end <= self.selection.start {
 290            return;
 291        }
 292        let text = text.text_for_range(self.selection.start..self.selection.end);
 293        cx.write_to_clipboard(ClipboardItem::new_string(text));
 294    }
 295
 296    fn parse(&mut self, cx: &mut Context<Self>) {
 297        if self.source.is_empty() {
 298            return;
 299        }
 300
 301        if self.pending_parse.is_some() {
 302            self.should_reparse = true;
 303            return;
 304        }
 305        self.should_reparse = false;
 306        self.pending_parse = Some(self.start_background_parse(cx));
 307    }
 308
 309    fn start_background_parse(&self, cx: &Context<Self>) -> Task<()> {
 310        let source = self.source.clone();
 311        let should_parse_links_only = self.options.parse_links_only;
 312        let language_registry = self.language_registry.clone();
 313        let fallback = self.fallback_code_block_language.clone();
 314
 315        let parsed = cx.background_spawn(async move {
 316            if should_parse_links_only {
 317                return (
 318                    ParsedMarkdown {
 319                        events: Arc::from(parse_links_only(source.as_ref())),
 320                        source,
 321                        languages_by_name: TreeMap::default(),
 322                        languages_by_path: TreeMap::default(),
 323                    },
 324                    Default::default(),
 325                );
 326            }
 327
 328            let (events, language_names, paths) = parse_markdown(&source);
 329            let mut images_by_source_offset = HashMap::default();
 330            let mut languages_by_name = TreeMap::default();
 331            let mut languages_by_path = TreeMap::default();
 332            if let Some(registry) = language_registry.as_ref() {
 333                for name in language_names {
 334                    let language = if !name.is_empty() {
 335                        registry.language_for_name_or_extension(&name).left_future()
 336                    } else if let Some(fallback) = &fallback {
 337                        registry.language_for_name(fallback.as_ref()).right_future()
 338                    } else {
 339                        continue;
 340                    };
 341                    if let Ok(language) = language.await {
 342                        languages_by_name.insert(name, language);
 343                    }
 344                }
 345
 346                for path in paths {
 347                    if let Ok(language) = registry
 348                        .load_language_for_file_path(Path::new(path.as_ref()))
 349                        .await
 350                    {
 351                        languages_by_path.insert(path, language);
 352                    }
 353                }
 354            }
 355
 356            for (range, event) in &events {
 357                if let MarkdownEvent::Start(MarkdownTag::Image { dest_url, .. }) = event
 358                    && let Some(data_url) = dest_url.strip_prefix("data:")
 359                {
 360                    let Some((mime_info, data)) = data_url.split_once(',') else {
 361                        continue;
 362                    };
 363                    let Some((mime_type, encoding)) = mime_info.split_once(';') else {
 364                        continue;
 365                    };
 366                    let Some(format) = ImageFormat::from_mime_type(mime_type) else {
 367                        continue;
 368                    };
 369                    let is_base64 = encoding == "base64";
 370                    if is_base64
 371                        && let Some(bytes) = base64::prelude::BASE64_STANDARD
 372                            .decode(data)
 373                            .log_with_level(Level::Debug)
 374                    {
 375                        let image = Arc::new(Image::from_bytes(format, bytes));
 376                        images_by_source_offset.insert(range.start, image);
 377                    }
 378                }
 379            }
 380
 381            (
 382                ParsedMarkdown {
 383                    source,
 384                    events: Arc::from(events),
 385                    languages_by_name,
 386                    languages_by_path,
 387                },
 388                images_by_source_offset,
 389            )
 390        });
 391
 392        cx.spawn(async move |this, cx| {
 393            let (parsed, images_by_source_offset) = parsed.await;
 394
 395            this.update(cx, |this, cx| {
 396                this.parsed_markdown = parsed;
 397                this.images_by_source_offset = images_by_source_offset;
 398                this.pending_parse.take();
 399                if this.should_reparse {
 400                    this.parse(cx);
 401                }
 402                cx.refresh_windows();
 403            })
 404            .ok();
 405        })
 406    }
 407}
 408
 409impl Focusable for Markdown {
 410    fn focus_handle(&self, _cx: &App) -> FocusHandle {
 411        self.focus_handle.clone()
 412    }
 413}
 414
 415#[derive(Debug, Default, Clone)]
 416enum SelectMode {
 417    #[default]
 418    Character,
 419    Word(Range<usize>),
 420    Line(Range<usize>),
 421    All,
 422}
 423
 424#[derive(Clone, Default)]
 425struct Selection {
 426    start: usize,
 427    end: usize,
 428    reversed: bool,
 429    pending: bool,
 430    mode: SelectMode,
 431}
 432
 433impl Selection {
 434    fn set_head(&mut self, head: usize, rendered_text: &RenderedText) {
 435        match &self.mode {
 436            SelectMode::Character => {
 437                if head < self.tail() {
 438                    if !self.reversed {
 439                        self.end = self.start;
 440                        self.reversed = true;
 441                    }
 442                    self.start = head;
 443                } else {
 444                    if self.reversed {
 445                        self.start = self.end;
 446                        self.reversed = false;
 447                    }
 448                    self.end = head;
 449                }
 450            }
 451            SelectMode::Word(original_range) | SelectMode::Line(original_range) => {
 452                let head_range = if matches!(self.mode, SelectMode::Word(_)) {
 453                    rendered_text.surrounding_word_range(head)
 454                } else {
 455                    rendered_text.surrounding_line_range(head)
 456                };
 457
 458                if head < original_range.start {
 459                    self.start = head_range.start;
 460                    self.end = original_range.end;
 461                    self.reversed = true;
 462                } else if head >= original_range.end {
 463                    self.start = original_range.start;
 464                    self.end = head_range.end;
 465                    self.reversed = false;
 466                } else {
 467                    self.start = original_range.start;
 468                    self.end = original_range.end;
 469                    self.reversed = false;
 470                }
 471            }
 472            SelectMode::All => {
 473                self.start = 0;
 474                self.end = rendered_text
 475                    .lines
 476                    .last()
 477                    .map(|line| line.source_end)
 478                    .unwrap_or(0);
 479                self.reversed = false;
 480            }
 481        }
 482    }
 483
 484    fn tail(&self) -> usize {
 485        if self.reversed { self.end } else { self.start }
 486    }
 487}
 488
 489#[derive(Debug, Clone, Default)]
 490pub struct ParsedMarkdown {
 491    pub source: SharedString,
 492    pub events: Arc<[(Range<usize>, MarkdownEvent)]>,
 493    pub languages_by_name: TreeMap<SharedString, Arc<Language>>,
 494    pub languages_by_path: TreeMap<Arc<str>, Arc<Language>>,
 495}
 496
 497impl ParsedMarkdown {
 498    pub fn source(&self) -> &SharedString {
 499        &self.source
 500    }
 501
 502    pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
 503        &self.events
 504    }
 505}
 506
 507pub struct MarkdownElement {
 508    markdown: Entity<Markdown>,
 509    style: MarkdownStyle,
 510    code_block_renderer: CodeBlockRenderer,
 511    on_url_click: Option<Box<dyn Fn(SharedString, &mut Window, &mut App)>>,
 512}
 513
 514impl MarkdownElement {
 515    pub fn new(markdown: Entity<Markdown>, style: MarkdownStyle) -> Self {
 516        Self {
 517            markdown,
 518            style,
 519            code_block_renderer: CodeBlockRenderer::Default {
 520                copy_button: true,
 521                copy_button_on_hover: false,
 522                border: false,
 523            },
 524            on_url_click: None,
 525        }
 526    }
 527
 528    #[cfg(any(test, feature = "test-support"))]
 529    pub fn rendered_text(
 530        markdown: Entity<Markdown>,
 531        cx: &mut gpui::VisualTestContext,
 532        style: impl FnOnce(&Window, &App) -> MarkdownStyle,
 533    ) -> String {
 534        use gpui::size;
 535
 536        let (text, _) = cx.draw(
 537            Default::default(),
 538            size(px(600.0), px(600.0)),
 539            |window, cx| Self::new(markdown, style(window, cx)),
 540        );
 541        text.text
 542            .lines
 543            .iter()
 544            .map(|line| line.layout.wrapped_text())
 545            .collect::<Vec<_>>()
 546            .join("\n")
 547    }
 548
 549    pub fn code_block_renderer(mut self, variant: CodeBlockRenderer) -> Self {
 550        self.code_block_renderer = variant;
 551        self
 552    }
 553
 554    pub fn on_url_click(
 555        mut self,
 556        handler: impl Fn(SharedString, &mut Window, &mut App) + 'static,
 557    ) -> Self {
 558        self.on_url_click = Some(Box::new(handler));
 559        self
 560    }
 561
 562    fn paint_selection(
 563        &self,
 564        bounds: Bounds<Pixels>,
 565        rendered_text: &RenderedText,
 566        window: &mut Window,
 567        cx: &mut App,
 568    ) {
 569        let selection = self.markdown.read(cx).selection.clone();
 570        let selection_start = rendered_text.position_for_source_index(selection.start);
 571        let selection_end = rendered_text.position_for_source_index(selection.end);
 572        if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
 573            selection_start.zip(selection_end)
 574        {
 575            if start_position.y == end_position.y {
 576                window.paint_quad(quad(
 577                    Bounds::from_corners(
 578                        start_position,
 579                        point(end_position.x, end_position.y + end_line_height),
 580                    ),
 581                    Pixels::ZERO,
 582                    self.style.selection_background_color,
 583                    Edges::default(),
 584                    Hsla::transparent_black(),
 585                    BorderStyle::default(),
 586                ));
 587            } else {
 588                window.paint_quad(quad(
 589                    Bounds::from_corners(
 590                        start_position,
 591                        point(bounds.right(), start_position.y + start_line_height),
 592                    ),
 593                    Pixels::ZERO,
 594                    self.style.selection_background_color,
 595                    Edges::default(),
 596                    Hsla::transparent_black(),
 597                    BorderStyle::default(),
 598                ));
 599
 600                if end_position.y > start_position.y + start_line_height {
 601                    window.paint_quad(quad(
 602                        Bounds::from_corners(
 603                            point(bounds.left(), start_position.y + start_line_height),
 604                            point(bounds.right(), end_position.y),
 605                        ),
 606                        Pixels::ZERO,
 607                        self.style.selection_background_color,
 608                        Edges::default(),
 609                        Hsla::transparent_black(),
 610                        BorderStyle::default(),
 611                    ));
 612                }
 613
 614                window.paint_quad(quad(
 615                    Bounds::from_corners(
 616                        point(bounds.left(), end_position.y),
 617                        point(end_position.x, end_position.y + end_line_height),
 618                    ),
 619                    Pixels::ZERO,
 620                    self.style.selection_background_color,
 621                    Edges::default(),
 622                    Hsla::transparent_black(),
 623                    BorderStyle::default(),
 624                ));
 625            }
 626        }
 627    }
 628
 629    fn paint_mouse_listeners(
 630        &mut self,
 631        hitbox: &Hitbox,
 632        rendered_text: &RenderedText,
 633        window: &mut Window,
 634        cx: &mut App,
 635    ) {
 636        if self.style.prevent_mouse_interaction {
 637            return;
 638        }
 639
 640        let is_hovering_link = hitbox.is_hovered(window)
 641            && !self.markdown.read(cx).selection.pending
 642            && rendered_text
 643                .link_for_position(window.mouse_position())
 644                .is_some();
 645
 646        if !self.style.prevent_mouse_interaction {
 647            if is_hovering_link {
 648                window.set_cursor_style(CursorStyle::PointingHand, hitbox);
 649            } else {
 650                window.set_cursor_style(CursorStyle::IBeam, hitbox);
 651            }
 652        }
 653
 654        let on_open_url = self.on_url_click.take();
 655
 656        self.on_mouse_event(window, cx, {
 657            let rendered_text = rendered_text.clone();
 658            let hitbox = hitbox.clone();
 659            move |markdown, event: &MouseDownEvent, phase, window, cx| {
 660                if hitbox.is_hovered(window) {
 661                    if phase.bubble() {
 662                        if let Some(link) = rendered_text.link_for_position(event.position) {
 663                            markdown.pressed_link = Some(link.clone());
 664                        } else {
 665                            let source_index =
 666                                match rendered_text.source_index_for_position(event.position) {
 667                                    Ok(ix) | Err(ix) => ix,
 668                                };
 669                            let (range, mode) = match event.click_count {
 670                                1 => {
 671                                    let range = source_index..source_index;
 672                                    (range, SelectMode::Character)
 673                                }
 674                                2 => {
 675                                    let range = rendered_text.surrounding_word_range(source_index);
 676                                    (range.clone(), SelectMode::Word(range))
 677                                }
 678                                3 => {
 679                                    let range = rendered_text.surrounding_line_range(source_index);
 680                                    (range.clone(), SelectMode::Line(range))
 681                                }
 682                                _ => {
 683                                    let range = 0..rendered_text
 684                                        .lines
 685                                        .last()
 686                                        .map(|line| line.source_end)
 687                                        .unwrap_or(0);
 688                                    (range, SelectMode::All)
 689                                }
 690                            };
 691                            markdown.selection = Selection {
 692                                start: range.start,
 693                                end: range.end,
 694                                reversed: false,
 695                                pending: true,
 696                                mode,
 697                            };
 698                            window.focus(&markdown.focus_handle);
 699                        }
 700
 701                        window.prevent_default();
 702                        cx.notify();
 703                    }
 704                } else if phase.capture() {
 705                    markdown.selection = Selection::default();
 706                    markdown.pressed_link = None;
 707                    cx.notify();
 708                }
 709            }
 710        });
 711        self.on_mouse_event(window, cx, {
 712            let rendered_text = rendered_text.clone();
 713            let hitbox = hitbox.clone();
 714            let was_hovering_link = is_hovering_link;
 715            move |markdown, event: &MouseMoveEvent, phase, window, cx| {
 716                if phase.capture() {
 717                    return;
 718                }
 719
 720                if markdown.selection.pending {
 721                    let source_index = match rendered_text.source_index_for_position(event.position)
 722                    {
 723                        Ok(ix) | Err(ix) => ix,
 724                    };
 725                    markdown.selection.set_head(source_index, &rendered_text);
 726                    markdown.autoscroll_request = Some(source_index);
 727                    cx.notify();
 728                } else {
 729                    let is_hovering_link = hitbox.is_hovered(window)
 730                        && rendered_text.link_for_position(event.position).is_some();
 731                    if is_hovering_link != was_hovering_link {
 732                        cx.notify();
 733                    }
 734                }
 735            }
 736        });
 737        self.on_mouse_event(window, cx, {
 738            let rendered_text = rendered_text.clone();
 739            move |markdown, event: &MouseUpEvent, phase, window, cx| {
 740                if phase.bubble() {
 741                    if let Some(pressed_link) = markdown.pressed_link.take()
 742                        && Some(&pressed_link) == rendered_text.link_for_position(event.position)
 743                    {
 744                        if let Some(open_url) = on_open_url.as_ref() {
 745                            open_url(pressed_link.destination_url, window, cx);
 746                        } else {
 747                            cx.open_url(&pressed_link.destination_url);
 748                        }
 749                    }
 750                } else if markdown.selection.pending {
 751                    markdown.selection.pending = false;
 752                    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
 753                    {
 754                        let text = rendered_text
 755                            .text_for_range(markdown.selection.start..markdown.selection.end);
 756                        cx.write_to_primary(ClipboardItem::new_string(text))
 757                    }
 758                    cx.notify();
 759                }
 760            }
 761        });
 762    }
 763
 764    fn autoscroll(
 765        &self,
 766        rendered_text: &RenderedText,
 767        window: &mut Window,
 768        cx: &mut App,
 769    ) -> Option<()> {
 770        let autoscroll_index = self
 771            .markdown
 772            .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
 773        let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
 774
 775        let text_style = self.style.base_text_style.clone();
 776        let font_id = window.text_system().resolve_font(&text_style.font());
 777        let font_size = text_style.font_size.to_pixels(window.rem_size());
 778        let em_width = window.text_system().em_width(font_id, font_size).unwrap();
 779        window.request_autoscroll(Bounds::from_corners(
 780            point(position.x - 3. * em_width, position.y - 3. * line_height),
 781            point(position.x + 3. * em_width, position.y + 3. * line_height),
 782        ));
 783        Some(())
 784    }
 785
 786    fn on_mouse_event<T: MouseEvent>(
 787        &self,
 788        window: &mut Window,
 789        _cx: &mut App,
 790        mut f: impl 'static
 791        + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
 792    ) {
 793        window.on_mouse_event({
 794            let markdown = self.markdown.downgrade();
 795            move |event, phase, window, cx| {
 796                markdown
 797                    .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
 798                    .log_err();
 799            }
 800        });
 801    }
 802}
 803
 804impl Styled for MarkdownElement {
 805    fn style(&mut self) -> &mut StyleRefinement {
 806        &mut self.style.container_style
 807    }
 808}
 809
 810impl Element for MarkdownElement {
 811    type RequestLayoutState = RenderedMarkdown;
 812    type PrepaintState = Hitbox;
 813
 814    fn id(&self) -> Option<ElementId> {
 815        None
 816    }
 817
 818    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
 819        None
 820    }
 821
 822    fn request_layout(
 823        &mut self,
 824        _id: Option<&GlobalElementId>,
 825        _inspector_id: Option<&gpui::InspectorElementId>,
 826        window: &mut Window,
 827        cx: &mut App,
 828    ) -> (gpui::LayoutId, Self::RequestLayoutState) {
 829        let mut builder = MarkdownElementBuilder::new(
 830            &self.style.container_style,
 831            self.style.base_text_style.clone(),
 832            self.style.syntax.clone(),
 833        );
 834        let (parsed_markdown, images) = {
 835            let markdown = self.markdown.read(cx);
 836            (
 837                markdown.parsed_markdown.clone(),
 838                markdown.images_by_source_offset.clone(),
 839            )
 840        };
 841        let markdown_end = if let Some(last) = parsed_markdown.events.last() {
 842            last.0.end
 843        } else {
 844            0
 845        };
 846        let mut code_block_ids = HashSet::default();
 847
 848        let mut current_img_block_range: Option<Range<usize>> = None;
 849        for (index, (range, event)) in parsed_markdown.events.iter().enumerate() {
 850            // Skip alt text for images that rendered
 851            if let Some(current_img_block_range) = &current_img_block_range
 852                && current_img_block_range.end > range.end
 853            {
 854                continue;
 855            }
 856
 857            match event {
 858                MarkdownEvent::Start(tag) => {
 859                    match tag {
 860                        MarkdownTag::Image { .. } => {
 861                            if let Some(image) = images.get(&range.start) {
 862                                current_img_block_range = Some(range.clone());
 863                                builder.modify_current_div(|el| {
 864                                    el.items_center()
 865                                        .flex()
 866                                        .flex_row()
 867                                        .child(img(image.clone()))
 868                                });
 869                            }
 870                        }
 871                        MarkdownTag::Paragraph => {
 872                            builder.push_div(
 873                                div().when(!self.style.height_is_multiple_of_line_height, |el| {
 874                                    el.mb_2().line_height(rems(1.3))
 875                                }),
 876                                range,
 877                                markdown_end,
 878                            );
 879                        }
 880                        MarkdownTag::Heading { level, .. } => {
 881                            let mut heading = div().mb_2();
 882
 883                            heading = apply_heading_style(
 884                                heading,
 885                                *level,
 886                                self.style.heading_level_styles.as_ref(),
 887                            );
 888
 889                            heading.style().refine(&self.style.heading);
 890
 891                            let text_style = self.style.heading.text_style().clone();
 892
 893                            builder.push_text_style(text_style);
 894                            builder.push_div(heading, range, markdown_end);
 895                        }
 896                        MarkdownTag::BlockQuote => {
 897                            builder.push_text_style(self.style.block_quote.clone());
 898                            builder.push_div(
 899                                div()
 900                                    .pl_4()
 901                                    .mb_2()
 902                                    .border_l_4()
 903                                    .border_color(self.style.block_quote_border_color),
 904                                range,
 905                                markdown_end,
 906                            );
 907                        }
 908                        MarkdownTag::CodeBlock { kind, .. } => {
 909                            let language = match kind {
 910                                CodeBlockKind::Fenced => None,
 911                                CodeBlockKind::FencedLang(language) => {
 912                                    parsed_markdown.languages_by_name.get(language).cloned()
 913                                }
 914                                CodeBlockKind::FencedSrc(path_range) => parsed_markdown
 915                                    .languages_by_path
 916                                    .get(&path_range.path)
 917                                    .cloned(),
 918                                _ => None,
 919                            };
 920
 921                            let is_indented = matches!(kind, CodeBlockKind::Indented);
 922                            let scroll_handle = if self.style.code_block_overflow_x_scroll {
 923                                code_block_ids.insert(range.start);
 924                                Some(self.markdown.update(cx, |markdown, _| {
 925                                    markdown.code_block_scroll_handle(range.start)
 926                                }))
 927                            } else {
 928                                None
 929                            };
 930
 931                            match (&self.code_block_renderer, is_indented) {
 932                                (CodeBlockRenderer::Default { .. }, _) | (_, true) => {
 933                                    // This is a parent container that we can position the copy button inside.
 934                                    let parent_container =
 935                                        div().group("code_block").relative().w_full();
 936
 937                                    let mut parent_container: AnyDiv = if let Some(scroll_handle) =
 938                                        scroll_handle.as_ref()
 939                                    {
 940                                        let scrollbars = Scrollbars::new(ScrollAxes::Horizontal)
 941                                            .id(("markdown-code-block-scrollbar", range.start))
 942                                            .tracked_scroll_handle(scroll_handle)
 943                                            .with_track_along(
 944                                                ScrollAxes::Horizontal,
 945                                                cx.theme().colors().editor_background,
 946                                            )
 947                                            .notify_content();
 948
 949                                        parent_container
 950                                            .rounded_lg()
 951                                            .custom_scrollbars(scrollbars, window, cx)
 952                                            .into()
 953                                    } else {
 954                                        parent_container.into()
 955                                    };
 956
 957                                    if let CodeBlockRenderer::Default { border: true, .. } =
 958                                        &self.code_block_renderer
 959                                    {
 960                                        parent_container = parent_container
 961                                            .rounded_md()
 962                                            .border_1()
 963                                            .border_color(cx.theme().colors().border_variant);
 964                                    }
 965
 966                                    parent_container.style().refine(&self.style.code_block);
 967                                    builder.push_div(parent_container, range, markdown_end);
 968
 969                                    let code_block = div()
 970                                        .id(("code-block", range.start))
 971                                        .rounded_lg()
 972                                        .map(|mut code_block| {
 973                                            if let Some(scroll_handle) = scroll_handle.as_ref() {
 974                                                code_block.style().restrict_scroll_to_axis =
 975                                                    Some(true);
 976                                                code_block
 977                                                    .flex()
 978                                                    .overflow_x_scroll()
 979                                                    .track_scroll(scroll_handle)
 980                                            } else {
 981                                                code_block.w_full()
 982                                            }
 983                                        });
 984
 985                                    builder.push_text_style(self.style.code_block.text.to_owned());
 986                                    builder.push_code_block(language);
 987                                    builder.push_div(code_block, range, markdown_end);
 988                                }
 989                                (CodeBlockRenderer::Custom { .. }, _) => {}
 990                            }
 991                        }
 992                        MarkdownTag::HtmlBlock => builder.push_div(div(), range, markdown_end),
 993                        MarkdownTag::List(bullet_index) => {
 994                            builder.push_list(*bullet_index);
 995                            builder.push_div(div().pl_2p5(), range, markdown_end);
 996                        }
 997                        MarkdownTag::Item => {
 998                            let bullet = if let Some((_, MarkdownEvent::TaskListMarker(checked))) =
 999                                parsed_markdown.events.get(index.saturating_add(1))
1000                            {
1001                                let source = &parsed_markdown.source()[range.clone()];
1002
1003                                Checkbox::new(
1004                                    ElementId::Name(source.to_string().into()),
1005                                    if *checked {
1006                                        ToggleState::Selected
1007                                    } else {
1008                                        ToggleState::Unselected
1009                                    },
1010                                )
1011                                .fill()
1012                                .visualization_only(true)
1013                                .into_any_element()
1014                            } else if let Some(bullet_index) = builder.next_bullet_index() {
1015                                div().child(format!("{}.", bullet_index)).into_any_element()
1016                            } else {
1017                                div().child("").into_any_element()
1018                            };
1019                            builder.push_div(
1020                                div()
1021                                    .when(!self.style.height_is_multiple_of_line_height, |el| {
1022                                        el.mb_1().gap_1().line_height(rems(1.3))
1023                                    })
1024                                    .h_flex()
1025                                    .items_start()
1026                                    .child(bullet),
1027                                range,
1028                                markdown_end,
1029                            );
1030                            // Without `w_0`, text doesn't wrap to the width of the container.
1031                            builder.push_div(div().flex_1().w_0(), range, markdown_end);
1032                        }
1033                        MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
1034                            font_style: Some(FontStyle::Italic),
1035                            ..Default::default()
1036                        }),
1037                        MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
1038                            font_weight: Some(FontWeight::BOLD),
1039                            ..Default::default()
1040                        }),
1041                        MarkdownTag::Strikethrough => {
1042                            builder.push_text_style(TextStyleRefinement {
1043                                strikethrough: Some(StrikethroughStyle {
1044                                    thickness: px(1.),
1045                                    color: None,
1046                                }),
1047                                ..Default::default()
1048                            })
1049                        }
1050                        MarkdownTag::Link { dest_url, .. } => {
1051                            if builder.code_block_stack.is_empty() {
1052                                builder.push_link(dest_url.clone(), range.clone());
1053                                let style = self
1054                                    .style
1055                                    .link_callback
1056                                    .as_ref()
1057                                    .and_then(|callback| callback(dest_url, cx))
1058                                    .unwrap_or_else(|| self.style.link.clone());
1059                                builder.push_text_style(style)
1060                            }
1061                        }
1062                        MarkdownTag::MetadataBlock(_) => {}
1063                        MarkdownTag::Table(alignments) => {
1064                            builder.table_alignments = alignments.clone();
1065
1066                            builder.push_div(
1067                                div()
1068                                    .id(("table", range.start))
1069                                    .min_w_0()
1070                                    .size_full()
1071                                    .mb_2()
1072                                    .border_1()
1073                                    .border_color(cx.theme().colors().border)
1074                                    .rounded_sm()
1075                                    .overflow_hidden(),
1076                                range,
1077                                markdown_end,
1078                            );
1079                        }
1080                        MarkdownTag::TableHead => {
1081                            let column_count = builder.table_alignments.len();
1082
1083                            builder.push_div(
1084                                div()
1085                                    .grid()
1086                                    .grid_cols(column_count as u16)
1087                                    .bg(cx.theme().colors().title_bar_background),
1088                                range,
1089                                markdown_end,
1090                            );
1091                            builder.push_text_style(TextStyleRefinement {
1092                                font_weight: Some(FontWeight::SEMIBOLD),
1093                                ..Default::default()
1094                            });
1095                        }
1096                        MarkdownTag::TableRow => {
1097                            let column_count = builder.table_alignments.len();
1098
1099                            builder.push_div(
1100                                div().grid().grid_cols(column_count as u16),
1101                                range,
1102                                markdown_end,
1103                            );
1104                        }
1105                        MarkdownTag::TableCell => {
1106                            builder.push_div(
1107                                div()
1108                                    .min_w_0()
1109                                    .border(px(0.5))
1110                                    .border_color(cx.theme().colors().border)
1111                                    .px_1()
1112                                    .py_0p5(),
1113                                range,
1114                                markdown_end,
1115                            );
1116                        }
1117                        _ => log::debug!("unsupported markdown tag {:?}", tag),
1118                    }
1119                }
1120                MarkdownEvent::End(tag) => match tag {
1121                    MarkdownTagEnd::Image => {
1122                        current_img_block_range.take();
1123                    }
1124                    MarkdownTagEnd::Paragraph => {
1125                        builder.pop_div();
1126                    }
1127                    MarkdownTagEnd::Heading(_) => {
1128                        builder.pop_div();
1129                        builder.pop_text_style()
1130                    }
1131                    MarkdownTagEnd::BlockQuote(_kind) => {
1132                        builder.pop_text_style();
1133                        builder.pop_div()
1134                    }
1135                    MarkdownTagEnd::CodeBlock => {
1136                        builder.trim_trailing_newline();
1137
1138                        builder.pop_div();
1139                        builder.pop_code_block();
1140                        builder.pop_text_style();
1141
1142                        if let CodeBlockRenderer::Default {
1143                            copy_button: true, ..
1144                        } = &self.code_block_renderer
1145                        {
1146                            builder.modify_current_div(|el| {
1147                                let content_range = parser::extract_code_block_content_range(
1148                                    &parsed_markdown.source()[range.clone()],
1149                                );
1150                                let content_range = content_range.start + range.start
1151                                    ..content_range.end + range.start;
1152
1153                                let code = parsed_markdown.source()[content_range].to_string();
1154                                let codeblock = render_copy_code_block_button(
1155                                    range.end,
1156                                    code,
1157                                    self.markdown.clone(),
1158                                    cx,
1159                                );
1160                                el.child(
1161                                    h_flex()
1162                                        .w_4()
1163                                        .absolute()
1164                                        .top_1p5()
1165                                        .right_1p5()
1166                                        .justify_end()
1167                                        .child(codeblock),
1168                                )
1169                            });
1170                        }
1171
1172                        if let CodeBlockRenderer::Default {
1173                            copy_button_on_hover: true,
1174                            ..
1175                        } = &self.code_block_renderer
1176                        {
1177                            builder.modify_current_div(|el| {
1178                                let content_range = parser::extract_code_block_content_range(
1179                                    &parsed_markdown.source()[range.clone()],
1180                                );
1181                                let content_range = content_range.start + range.start
1182                                    ..content_range.end + range.start;
1183
1184                                let code = parsed_markdown.source()[content_range].to_string();
1185                                let codeblock = render_copy_code_block_button(
1186                                    range.end,
1187                                    code,
1188                                    self.markdown.clone(),
1189                                    cx,
1190                                );
1191                                el.child(
1192                                    h_flex()
1193                                        .w_4()
1194                                        .absolute()
1195                                        .top_0()
1196                                        .right_0()
1197                                        .justify_end()
1198                                        .visible_on_hover("code_block")
1199                                        .child(codeblock),
1200                                )
1201                            });
1202                        }
1203
1204                        // Pop the parent container.
1205                        builder.pop_div();
1206                    }
1207                    MarkdownTagEnd::HtmlBlock => builder.pop_div(),
1208                    MarkdownTagEnd::List(_) => {
1209                        builder.pop_list();
1210                        builder.pop_div();
1211                    }
1212                    MarkdownTagEnd::Item => {
1213                        builder.pop_div();
1214                        builder.pop_div();
1215                    }
1216                    MarkdownTagEnd::Emphasis => builder.pop_text_style(),
1217                    MarkdownTagEnd::Strong => builder.pop_text_style(),
1218                    MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
1219                    MarkdownTagEnd::Link => {
1220                        if builder.code_block_stack.is_empty() {
1221                            builder.pop_text_style()
1222                        }
1223                    }
1224                    MarkdownTagEnd::Table => {
1225                        builder.pop_div();
1226                        builder.table_alignments.clear();
1227                    }
1228                    MarkdownTagEnd::TableHead => {
1229                        builder.pop_div();
1230                        builder.pop_text_style();
1231                    }
1232                    MarkdownTagEnd::TableRow => {
1233                        builder.pop_div();
1234                    }
1235                    MarkdownTagEnd::TableCell => {
1236                        builder.pop_div();
1237                    }
1238                    _ => log::debug!("unsupported markdown tag end: {:?}", tag),
1239                },
1240                MarkdownEvent::Text => {
1241                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1242                }
1243                MarkdownEvent::SubstitutedText(text) => {
1244                    builder.push_text(text, range.clone());
1245                }
1246                MarkdownEvent::Code => {
1247                    builder.push_text_style(self.style.inline_code.clone());
1248                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1249                    builder.pop_text_style();
1250                }
1251                MarkdownEvent::Html => {
1252                    let html = &parsed_markdown.source[range.clone()];
1253                    if html.starts_with("<!--") {
1254                        builder.html_comment = true;
1255                    }
1256                    if html.trim_end().ends_with("-->") {
1257                        builder.html_comment = false;
1258                        continue;
1259                    }
1260                    if builder.html_comment {
1261                        continue;
1262                    }
1263                    builder.push_text(html, range.clone());
1264                }
1265                MarkdownEvent::InlineHtml => {
1266                    let html = &parsed_markdown.source[range.clone()];
1267                    if html.starts_with("<code>") {
1268                        builder.push_text_style(self.style.inline_code.clone());
1269                        continue;
1270                    }
1271                    if html.trim_end().starts_with("</code>") {
1272                        builder.pop_text_style();
1273                        continue;
1274                    }
1275                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1276                }
1277                MarkdownEvent::Rule => {
1278                    builder.push_div(
1279                        div()
1280                            .border_b_1()
1281                            .my_2()
1282                            .border_color(self.style.rule_color),
1283                        range,
1284                        markdown_end,
1285                    );
1286                    builder.pop_div()
1287                }
1288                MarkdownEvent::SoftBreak => builder.push_text(" ", range.clone()),
1289                MarkdownEvent::HardBreak => builder.push_text("\n", range.clone()),
1290                MarkdownEvent::TaskListMarker(_) => {
1291                    // handled inside the `MarkdownTag::Item` case
1292                }
1293                _ => log::debug!("unsupported markdown event {:?}", event),
1294            }
1295        }
1296        if self.style.code_block_overflow_x_scroll {
1297            let code_block_ids = code_block_ids;
1298            self.markdown.update(cx, move |markdown, _| {
1299                markdown.retain_code_block_scroll_handles(&code_block_ids);
1300            });
1301        } else {
1302            self.markdown
1303                .update(cx, |markdown, _| markdown.clear_code_block_scroll_handles());
1304        }
1305        let mut rendered_markdown = builder.build();
1306        let child_layout_id = rendered_markdown.element.request_layout(window, cx);
1307        let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
1308        (layout_id, rendered_markdown)
1309    }
1310
1311    fn prepaint(
1312        &mut self,
1313        _id: Option<&GlobalElementId>,
1314        _inspector_id: Option<&gpui::InspectorElementId>,
1315        bounds: Bounds<Pixels>,
1316        rendered_markdown: &mut Self::RequestLayoutState,
1317        window: &mut Window,
1318        cx: &mut App,
1319    ) -> Self::PrepaintState {
1320        let focus_handle = self.markdown.read(cx).focus_handle.clone();
1321        window.set_focus_handle(&focus_handle, cx);
1322        window.set_view_id(self.markdown.entity_id());
1323
1324        let hitbox = window.insert_hitbox(bounds, HitboxBehavior::Normal);
1325        rendered_markdown.element.prepaint(window, cx);
1326        self.autoscroll(&rendered_markdown.text, window, cx);
1327        hitbox
1328    }
1329
1330    fn paint(
1331        &mut self,
1332        _id: Option<&GlobalElementId>,
1333        _inspector_id: Option<&gpui::InspectorElementId>,
1334        bounds: Bounds<Pixels>,
1335        rendered_markdown: &mut Self::RequestLayoutState,
1336        hitbox: &mut Self::PrepaintState,
1337        window: &mut Window,
1338        cx: &mut App,
1339    ) {
1340        let mut context = KeyContext::default();
1341        context.add("Markdown");
1342        window.set_key_context(context);
1343        window.on_action(std::any::TypeId::of::<crate::Copy>(), {
1344            let entity = self.markdown.clone();
1345            let text = rendered_markdown.text.clone();
1346            move |_, phase, window, cx| {
1347                let text = text.clone();
1348                if phase == DispatchPhase::Bubble {
1349                    entity.update(cx, move |this, cx| this.copy(&text, window, cx))
1350                }
1351            }
1352        });
1353
1354        self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
1355        rendered_markdown.element.paint(window, cx);
1356        self.paint_selection(bounds, &rendered_markdown.text, window, cx);
1357    }
1358}
1359
1360fn apply_heading_style(
1361    mut heading: Div,
1362    level: pulldown_cmark::HeadingLevel,
1363    custom_styles: Option<&HeadingLevelStyles>,
1364) -> Div {
1365    heading = match level {
1366        pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
1367        pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
1368        pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
1369        pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
1370        pulldown_cmark::HeadingLevel::H5 => heading.text_base(),
1371        pulldown_cmark::HeadingLevel::H6 => heading.text_sm(),
1372    };
1373
1374    if let Some(styles) = custom_styles {
1375        let style_opt = match level {
1376            pulldown_cmark::HeadingLevel::H1 => &styles.h1,
1377            pulldown_cmark::HeadingLevel::H2 => &styles.h2,
1378            pulldown_cmark::HeadingLevel::H3 => &styles.h3,
1379            pulldown_cmark::HeadingLevel::H4 => &styles.h4,
1380            pulldown_cmark::HeadingLevel::H5 => &styles.h5,
1381            pulldown_cmark::HeadingLevel::H6 => &styles.h6,
1382        };
1383
1384        if let Some(style) = style_opt {
1385            heading.style().text = style.clone();
1386        }
1387    }
1388
1389    heading
1390}
1391
1392fn render_copy_code_block_button(
1393    id: usize,
1394    code: String,
1395    markdown: Entity<Markdown>,
1396    cx: &App,
1397) -> impl IntoElement {
1398    let id = ElementId::named_usize("copy-markdown-code", id);
1399    let was_copied = markdown.read(cx).copied_code_blocks.contains(&id);
1400    IconButton::new(
1401        id.clone(),
1402        if was_copied {
1403            IconName::Check
1404        } else {
1405            IconName::Copy
1406        },
1407    )
1408    .icon_color(Color::Muted)
1409    .icon_size(IconSize::Small)
1410    .style(ButtonStyle::Filled)
1411    .shape(ui::IconButtonShape::Square)
1412    .tooltip(Tooltip::text("Copy"))
1413    .on_click({
1414        let markdown = markdown;
1415        move |_event, _window, cx| {
1416            let id = id.clone();
1417            markdown.update(cx, |this, cx| {
1418                this.copied_code_blocks.insert(id.clone());
1419
1420                cx.write_to_clipboard(ClipboardItem::new_string(code.clone()));
1421
1422                cx.spawn(async move |this, cx| {
1423                    cx.background_executor().timer(Duration::from_secs(2)).await;
1424
1425                    cx.update(|cx| {
1426                        this.update(cx, |this, cx| {
1427                            this.copied_code_blocks.remove(&id);
1428                            cx.notify();
1429                        })
1430                    })
1431                    .ok();
1432                })
1433                .detach();
1434            });
1435        }
1436    })
1437}
1438
1439impl IntoElement for MarkdownElement {
1440    type Element = Self;
1441
1442    fn into_element(self) -> Self::Element {
1443        self
1444    }
1445}
1446
1447pub enum AnyDiv {
1448    Div(Div),
1449    Stateful(Stateful<Div>),
1450}
1451
1452impl AnyDiv {
1453    fn into_any_element(self) -> AnyElement {
1454        match self {
1455            Self::Div(div) => div.into_any_element(),
1456            Self::Stateful(div) => div.into_any_element(),
1457        }
1458    }
1459}
1460
1461impl From<Div> for AnyDiv {
1462    fn from(value: Div) -> Self {
1463        Self::Div(value)
1464    }
1465}
1466
1467impl From<Stateful<Div>> for AnyDiv {
1468    fn from(value: Stateful<Div>) -> Self {
1469        Self::Stateful(value)
1470    }
1471}
1472
1473impl Styled for AnyDiv {
1474    fn style(&mut self) -> &mut StyleRefinement {
1475        match self {
1476            Self::Div(div) => div.style(),
1477            Self::Stateful(div) => div.style(),
1478        }
1479    }
1480}
1481
1482impl ParentElement for AnyDiv {
1483    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1484        match self {
1485            Self::Div(div) => div.extend(elements),
1486            Self::Stateful(div) => div.extend(elements),
1487        }
1488    }
1489}
1490
1491struct MarkdownElementBuilder {
1492    div_stack: Vec<AnyDiv>,
1493    rendered_lines: Vec<RenderedLine>,
1494    pending_line: PendingLine,
1495    rendered_links: Vec<RenderedLink>,
1496    current_source_index: usize,
1497    html_comment: bool,
1498    base_text_style: TextStyle,
1499    text_style_stack: Vec<TextStyleRefinement>,
1500    code_block_stack: Vec<Option<Arc<Language>>>,
1501    list_stack: Vec<ListStackEntry>,
1502    table_alignments: Vec<Alignment>,
1503    syntax_theme: Arc<SyntaxTheme>,
1504}
1505
1506#[derive(Default)]
1507struct PendingLine {
1508    text: String,
1509    runs: Vec<TextRun>,
1510    source_mappings: Vec<SourceMapping>,
1511}
1512
1513struct ListStackEntry {
1514    bullet_index: Option<u64>,
1515}
1516
1517impl MarkdownElementBuilder {
1518    fn new(
1519        container_style: &StyleRefinement,
1520        base_text_style: TextStyle,
1521        syntax_theme: Arc<SyntaxTheme>,
1522    ) -> Self {
1523        Self {
1524            div_stack: vec![{
1525                let mut base_div = div();
1526                base_div.style().refine(container_style);
1527                base_div.debug_selector(|| "inner".into()).into()
1528            }],
1529            rendered_lines: Vec::new(),
1530            pending_line: PendingLine::default(),
1531            rendered_links: Vec::new(),
1532            current_source_index: 0,
1533            html_comment: false,
1534            base_text_style,
1535            text_style_stack: Vec::new(),
1536            code_block_stack: Vec::new(),
1537            list_stack: Vec::new(),
1538            table_alignments: Vec::new(),
1539            syntax_theme,
1540        }
1541    }
1542
1543    fn push_text_style(&mut self, style: TextStyleRefinement) {
1544        self.text_style_stack.push(style);
1545    }
1546
1547    fn text_style(&self) -> TextStyle {
1548        let mut style = self.base_text_style.clone();
1549        for refinement in &self.text_style_stack {
1550            style.refine(refinement);
1551        }
1552        style
1553    }
1554
1555    fn pop_text_style(&mut self) {
1556        self.text_style_stack.pop();
1557    }
1558
1559    fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
1560        let mut div = div.into();
1561        self.flush_text();
1562
1563        if range.start == 0 {
1564            // Remove the top margin on the first element.
1565            div.style().refine(&StyleRefinement {
1566                margin: gpui::EdgesRefinement {
1567                    top: Some(Length::Definite(px(0.).into())),
1568                    left: None,
1569                    right: None,
1570                    bottom: None,
1571                },
1572                ..Default::default()
1573            });
1574        }
1575
1576        if range.end == markdown_end {
1577            div.style().refine(&StyleRefinement {
1578                margin: gpui::EdgesRefinement {
1579                    top: None,
1580                    left: None,
1581                    right: None,
1582                    bottom: Some(Length::Definite(rems(0.).into())),
1583                },
1584                ..Default::default()
1585            });
1586        }
1587
1588        self.div_stack.push(div);
1589    }
1590
1591    fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
1592        self.flush_text();
1593        if let Some(div) = self.div_stack.pop() {
1594            self.div_stack.push(f(div));
1595        }
1596    }
1597
1598    fn pop_div(&mut self) {
1599        self.flush_text();
1600        let div = self.div_stack.pop().unwrap().into_any_element();
1601        self.div_stack.last_mut().unwrap().extend(iter::once(div));
1602    }
1603
1604    fn push_list(&mut self, bullet_index: Option<u64>) {
1605        self.list_stack.push(ListStackEntry { bullet_index });
1606    }
1607
1608    fn next_bullet_index(&mut self) -> Option<u64> {
1609        self.list_stack.last_mut().and_then(|entry| {
1610            let item_index = entry.bullet_index.as_mut()?;
1611            *item_index += 1;
1612            Some(*item_index - 1)
1613        })
1614    }
1615
1616    fn pop_list(&mut self) {
1617        self.list_stack.pop();
1618    }
1619
1620    fn push_code_block(&mut self, language: Option<Arc<Language>>) {
1621        self.code_block_stack.push(language);
1622    }
1623
1624    fn pop_code_block(&mut self) {
1625        self.code_block_stack.pop();
1626    }
1627
1628    fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
1629        self.rendered_links.push(RenderedLink {
1630            source_range,
1631            destination_url,
1632        });
1633    }
1634
1635    fn push_text(&mut self, text: &str, source_range: Range<usize>) {
1636        self.pending_line.source_mappings.push(SourceMapping {
1637            rendered_index: self.pending_line.text.len(),
1638            source_index: source_range.start,
1639        });
1640        self.pending_line.text.push_str(text);
1641        self.current_source_index = source_range.end;
1642
1643        if let Some(Some(language)) = self.code_block_stack.last() {
1644            let mut offset = 0;
1645            for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
1646                if range.start > offset {
1647                    self.pending_line
1648                        .runs
1649                        .push(self.text_style().to_run(range.start - offset));
1650                }
1651
1652                let mut run_style = self.text_style();
1653                if let Some(highlight) = highlight_id.style(&self.syntax_theme) {
1654                    run_style = run_style.highlight(highlight);
1655                }
1656                self.pending_line.runs.push(run_style.to_run(range.len()));
1657                offset = range.end;
1658            }
1659
1660            if offset < text.len() {
1661                self.pending_line
1662                    .runs
1663                    .push(self.text_style().to_run(text.len() - offset));
1664            }
1665        } else {
1666            self.pending_line
1667                .runs
1668                .push(self.text_style().to_run(text.len()));
1669        }
1670    }
1671
1672    fn trim_trailing_newline(&mut self) {
1673        if self.pending_line.text.ends_with('\n') {
1674            self.pending_line
1675                .text
1676                .truncate(self.pending_line.text.len() - 1);
1677            self.pending_line.runs.last_mut().unwrap().len -= 1;
1678            self.current_source_index -= 1;
1679        }
1680    }
1681
1682    fn flush_text(&mut self) {
1683        let line = mem::take(&mut self.pending_line);
1684        if line.text.is_empty() {
1685            return;
1686        }
1687
1688        let text = StyledText::new(line.text).with_runs(line.runs);
1689        self.rendered_lines.push(RenderedLine {
1690            layout: text.layout().clone(),
1691            source_mappings: line.source_mappings,
1692            source_end: self.current_source_index,
1693        });
1694        self.div_stack.last_mut().unwrap().extend([text.into_any()]);
1695    }
1696
1697    fn build(mut self) -> RenderedMarkdown {
1698        debug_assert_eq!(self.div_stack.len(), 1);
1699        self.flush_text();
1700        RenderedMarkdown {
1701            element: self.div_stack.pop().unwrap().into_any_element(),
1702            text: RenderedText {
1703                lines: self.rendered_lines.into(),
1704                links: self.rendered_links.into(),
1705            },
1706        }
1707    }
1708}
1709
1710struct RenderedLine {
1711    layout: TextLayout,
1712    source_mappings: Vec<SourceMapping>,
1713    source_end: usize,
1714}
1715
1716impl RenderedLine {
1717    fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
1718        if source_index >= self.source_end {
1719            return self.layout.len();
1720        }
1721
1722        let mapping = match self
1723            .source_mappings
1724            .binary_search_by_key(&source_index, |probe| probe.source_index)
1725        {
1726            Ok(ix) => &self.source_mappings[ix],
1727            Err(ix) => &self.source_mappings[ix - 1],
1728        };
1729        mapping.rendered_index + (source_index - mapping.source_index)
1730    }
1731
1732    fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
1733        if rendered_index >= self.layout.len() {
1734            return self.source_end;
1735        }
1736
1737        let mapping = match self
1738            .source_mappings
1739            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
1740        {
1741            Ok(ix) => &self.source_mappings[ix],
1742            Err(ix) => &self.source_mappings[ix - 1],
1743        };
1744        mapping.source_index + (rendered_index - mapping.rendered_index)
1745    }
1746
1747    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1748        let line_rendered_index;
1749        let out_of_bounds;
1750        match self.layout.index_for_position(position) {
1751            Ok(ix) => {
1752                line_rendered_index = ix;
1753                out_of_bounds = false;
1754            }
1755            Err(ix) => {
1756                line_rendered_index = ix;
1757                out_of_bounds = true;
1758            }
1759        };
1760        let source_index = self.source_index_for_rendered_index(line_rendered_index);
1761        if out_of_bounds {
1762            Err(source_index)
1763        } else {
1764            Ok(source_index)
1765        }
1766    }
1767}
1768
1769#[derive(Copy, Clone, Debug, Default)]
1770struct SourceMapping {
1771    rendered_index: usize,
1772    source_index: usize,
1773}
1774
1775pub struct RenderedMarkdown {
1776    element: AnyElement,
1777    text: RenderedText,
1778}
1779
1780#[derive(Clone)]
1781struct RenderedText {
1782    lines: Rc<[RenderedLine]>,
1783    links: Rc<[RenderedLink]>,
1784}
1785
1786#[derive(Debug, Clone, Eq, PartialEq)]
1787struct RenderedLink {
1788    source_range: Range<usize>,
1789    destination_url: SharedString,
1790}
1791
1792impl RenderedText {
1793    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
1794        let mut lines = self.lines.iter().peekable();
1795
1796        while let Some(line) = lines.next() {
1797            let line_bounds = line.layout.bounds();
1798            if position.y > line_bounds.bottom() {
1799                if let Some(next_line) = lines.peek()
1800                    && position.y < next_line.layout.bounds().top()
1801                {
1802                    return Err(line.source_end);
1803                }
1804
1805                continue;
1806            }
1807
1808            return line.source_index_for_position(position);
1809        }
1810
1811        Err(self.lines.last().map_or(0, |line| line.source_end))
1812    }
1813
1814    fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
1815        for line in self.lines.iter() {
1816            let line_source_start = line.source_mappings.first().unwrap().source_index;
1817            if source_index < line_source_start {
1818                break;
1819            } else if source_index > line.source_end {
1820                continue;
1821            } else {
1822                let line_height = line.layout.line_height();
1823                let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
1824                let position = line.layout.position_for_index(rendered_index_within_line)?;
1825                return Some((position, line_height));
1826            }
1827        }
1828        None
1829    }
1830
1831    fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
1832        for line in self.lines.iter() {
1833            if source_index > line.source_end {
1834                continue;
1835            }
1836
1837            let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
1838            let rendered_index_in_line =
1839                line.rendered_index_for_source_index(source_index) - line_rendered_start;
1840            let text = line.layout.text();
1841            let previous_space = if let Some(idx) = text[0..rendered_index_in_line].rfind(' ') {
1842                idx + ' '.len_utf8()
1843            } else {
1844                0
1845            };
1846            let next_space = if let Some(idx) = text[rendered_index_in_line..].find(' ') {
1847                rendered_index_in_line + idx
1848            } else {
1849                text.len()
1850            };
1851
1852            return line.source_index_for_rendered_index(line_rendered_start + previous_space)
1853                ..line.source_index_for_rendered_index(line_rendered_start + next_space);
1854        }
1855
1856        source_index..source_index
1857    }
1858
1859    fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
1860        for line in self.lines.iter() {
1861            if source_index > line.source_end {
1862                continue;
1863            }
1864            let line_source_start = line.source_mappings.first().unwrap().source_index;
1865            return line_source_start..line.source_end;
1866        }
1867
1868        source_index..source_index
1869    }
1870
1871    fn text_for_range(&self, range: Range<usize>) -> String {
1872        let mut ret = vec![];
1873
1874        for line in self.lines.iter() {
1875            if range.start > line.source_end {
1876                continue;
1877            }
1878            let line_source_start = line.source_mappings.first().unwrap().source_index;
1879            if range.end < line_source_start {
1880                break;
1881            }
1882
1883            let text = line.layout.text();
1884
1885            let start = if range.start < line_source_start {
1886                0
1887            } else {
1888                line.rendered_index_for_source_index(range.start)
1889            };
1890            let end = if range.end > line.source_end {
1891                line.rendered_index_for_source_index(line.source_end)
1892            } else {
1893                line.rendered_index_for_source_index(range.end)
1894            }
1895            .min(text.len());
1896
1897            ret.push(text[start..end].to_string());
1898        }
1899        ret.join("\n")
1900    }
1901
1902    fn link_for_position(&self, position: Point<Pixels>) -> Option<&RenderedLink> {
1903        let source_index = self.source_index_for_position(position).ok()?;
1904        self.links
1905            .iter()
1906            .find(|link| link.source_range.contains(&source_index))
1907    }
1908}
1909
1910#[cfg(test)]
1911mod tests {
1912    use super::*;
1913    use gpui::{TestAppContext, size};
1914
1915    #[gpui::test]
1916    fn test_mappings(cx: &mut TestAppContext) {
1917        // Formatting.
1918        assert_mappings(
1919            &render_markdown("He*l*lo", cx),
1920            vec![vec![(0, 0), (1, 1), (2, 3), (3, 5), (4, 6), (5, 7)]],
1921        );
1922
1923        // Multiple lines.
1924        assert_mappings(
1925            &render_markdown("Hello\n\nWorld", cx),
1926            vec![
1927                vec![(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)],
1928                vec![(0, 7), (1, 8), (2, 9), (3, 10), (4, 11), (5, 12)],
1929            ],
1930        );
1931
1932        // Multi-byte characters.
1933        assert_mappings(
1934            &render_markdown("αβγ\n\nδεζ", cx),
1935            vec![
1936                vec![(0, 0), (2, 2), (4, 4), (6, 6)],
1937                vec![(0, 8), (2, 10), (4, 12), (6, 14)],
1938            ],
1939        );
1940
1941        // Smart quotes.
1942        assert_mappings(&render_markdown("\"", cx), vec![vec![(0, 0), (3, 1)]]);
1943        assert_mappings(
1944            &render_markdown("\"hey\"", cx),
1945            vec![vec![(0, 0), (3, 1), (4, 2), (5, 3), (6, 4), (9, 5)]],
1946        );
1947
1948        // HTML Comments are ignored
1949        assert_mappings(
1950            &render_markdown(
1951                "<!--\nrdoc-file=string.c\n- str.intern   -> symbol\n- str.to_sym   -> symbol\n-->\nReturns",
1952                cx,
1953            ),
1954            vec![vec![
1955                (0, 78),
1956                (1, 79),
1957                (2, 80),
1958                (3, 81),
1959                (4, 82),
1960                (5, 83),
1961                (6, 84),
1962            ]],
1963        );
1964    }
1965
1966    fn render_markdown(markdown: &str, cx: &mut TestAppContext) -> RenderedText {
1967        struct TestWindow;
1968
1969        impl Render for TestWindow {
1970            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
1971                div()
1972            }
1973        }
1974
1975        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
1976        let markdown = cx.new(|cx| Markdown::new(markdown.to_string().into(), None, None, cx));
1977        cx.run_until_parked();
1978        let (rendered, _) = cx.draw(
1979            Default::default(),
1980            size(px(600.0), px(600.0)),
1981            |_window, _cx| MarkdownElement::new(markdown, MarkdownStyle::default()),
1982        );
1983        rendered.text
1984    }
1985
1986    #[gpui::test]
1987    fn test_surrounding_word_range(cx: &mut TestAppContext) {
1988        let rendered = render_markdown("Hello world tesεζ", cx);
1989
1990        // Test word selection for "Hello"
1991        let word_range = rendered.surrounding_word_range(2); // Simulate click on 'l' in "Hello"
1992        let selected_text = rendered.text_for_range(word_range);
1993        assert_eq!(selected_text, "Hello");
1994
1995        // Test word selection for "world"
1996        let word_range = rendered.surrounding_word_range(7); // Simulate click on 'o' in "world"
1997        let selected_text = rendered.text_for_range(word_range);
1998        assert_eq!(selected_text, "world");
1999
2000        // Test word selection for "tesεζ"
2001        let word_range = rendered.surrounding_word_range(14); // Simulate click on 's' in "tesεζ"
2002        let selected_text = rendered.text_for_range(word_range);
2003        assert_eq!(selected_text, "tesεζ");
2004
2005        // Test word selection at word boundary (space)
2006        let word_range = rendered.surrounding_word_range(5); // Simulate click on space between "Hello" and "world", expect highlighting word to the left
2007        let selected_text = rendered.text_for_range(word_range);
2008        assert_eq!(selected_text, "Hello");
2009    }
2010
2011    #[gpui::test]
2012    fn test_surrounding_line_range(cx: &mut TestAppContext) {
2013        let rendered = render_markdown("First line\n\nSecond line\n\nThird lineεζ", cx);
2014
2015        // Test getting line range for first line
2016        let line_range = rendered.surrounding_line_range(5); // Simulate click somewhere in first line
2017        let selected_text = rendered.text_for_range(line_range);
2018        assert_eq!(selected_text, "First line");
2019
2020        // Test getting line range for second line
2021        let line_range = rendered.surrounding_line_range(13); // Simulate click at beginning in second line
2022        let selected_text = rendered.text_for_range(line_range);
2023        assert_eq!(selected_text, "Second line");
2024
2025        // Test getting line range for third line
2026        let line_range = rendered.surrounding_line_range(37); // Simulate click at end of third line with multi-byte chars
2027        let selected_text = rendered.text_for_range(line_range);
2028        assert_eq!(selected_text, "Third lineεζ");
2029    }
2030
2031    #[gpui::test]
2032    fn test_selection_head_movement(cx: &mut TestAppContext) {
2033        let rendered = render_markdown("Hello world test", cx);
2034
2035        let mut selection = Selection {
2036            start: 5,
2037            end: 5,
2038            reversed: false,
2039            pending: false,
2040            mode: SelectMode::Character,
2041        };
2042
2043        // Test forward selection
2044        selection.set_head(10, &rendered);
2045        assert_eq!(selection.start, 5);
2046        assert_eq!(selection.end, 10);
2047        assert!(!selection.reversed);
2048        assert_eq!(selection.tail(), 5);
2049
2050        // Test backward selection
2051        selection.set_head(2, &rendered);
2052        assert_eq!(selection.start, 2);
2053        assert_eq!(selection.end, 5);
2054        assert!(selection.reversed);
2055        assert_eq!(selection.tail(), 5);
2056
2057        // Test forward selection again from reversed state
2058        selection.set_head(15, &rendered);
2059        assert_eq!(selection.start, 5);
2060        assert_eq!(selection.end, 15);
2061        assert!(!selection.reversed);
2062        assert_eq!(selection.tail(), 5);
2063    }
2064
2065    #[gpui::test]
2066    fn test_word_selection_drag(cx: &mut TestAppContext) {
2067        let rendered = render_markdown("Hello world test", cx);
2068
2069        // Start with a simulated double-click on "world" (index 6-10)
2070        let word_range = rendered.surrounding_word_range(7); // Click on 'o' in "world"
2071        let mut selection = Selection {
2072            start: word_range.start,
2073            end: word_range.end,
2074            reversed: false,
2075            pending: true,
2076            mode: SelectMode::Word(word_range),
2077        };
2078
2079        // Drag forward to "test" - should expand selection to include "test"
2080        selection.set_head(13, &rendered); // Index in "test"
2081        assert_eq!(selection.start, 6); // Start of "world"
2082        assert_eq!(selection.end, 16); // End of "test"
2083        assert!(!selection.reversed);
2084        let selected_text = rendered.text_for_range(selection.start..selection.end);
2085        assert_eq!(selected_text, "world test");
2086
2087        // Drag backward to "Hello" - should expand selection to include "Hello"
2088        selection.set_head(2, &rendered); // Index in "Hello"
2089        assert_eq!(selection.start, 0); // Start of "Hello"
2090        assert_eq!(selection.end, 11); // End of "world" (original selection)
2091        assert!(selection.reversed);
2092        let selected_text = rendered.text_for_range(selection.start..selection.end);
2093        assert_eq!(selected_text, "Hello world");
2094
2095        // Drag back within original word - should revert to original selection
2096        selection.set_head(8, &rendered); // Back within "world"
2097        assert_eq!(selection.start, 6); // Start of "world"
2098        assert_eq!(selection.end, 11); // End of "world"
2099        assert!(!selection.reversed);
2100        let selected_text = rendered.text_for_range(selection.start..selection.end);
2101        assert_eq!(selected_text, "world");
2102    }
2103
2104    #[gpui::test]
2105    fn test_selection_with_markdown_formatting(cx: &mut TestAppContext) {
2106        let rendered = render_markdown(
2107            "This is **bold** text, this is *italic* text, use `code` here",
2108            cx,
2109        );
2110        let word_range = rendered.surrounding_word_range(10); // Inside "bold"
2111        let selected_text = rendered.text_for_range(word_range);
2112        assert_eq!(selected_text, "bold");
2113
2114        let word_range = rendered.surrounding_word_range(32); // Inside "italic"
2115        let selected_text = rendered.text_for_range(word_range);
2116        assert_eq!(selected_text, "italic");
2117
2118        let word_range = rendered.surrounding_word_range(51); // Inside "code"
2119        let selected_text = rendered.text_for_range(word_range);
2120        assert_eq!(selected_text, "code");
2121    }
2122
2123    #[gpui::test]
2124    fn test_all_selection(cx: &mut TestAppContext) {
2125        let rendered = render_markdown("Hello world\n\nThis is a test\n\nwith multiple lines", cx);
2126
2127        let total_length = rendered
2128            .lines
2129            .last()
2130            .map(|line| line.source_end)
2131            .unwrap_or(0);
2132
2133        let mut selection = Selection {
2134            start: 0,
2135            end: total_length,
2136            reversed: false,
2137            pending: true,
2138            mode: SelectMode::All,
2139        };
2140
2141        selection.set_head(5, &rendered); // Try to set head in middle
2142        assert_eq!(selection.start, 0);
2143        assert_eq!(selection.end, total_length);
2144        assert!(!selection.reversed);
2145
2146        selection.set_head(25, &rendered); // Try to set head near end
2147        assert_eq!(selection.start, 0);
2148        assert_eq!(selection.end, total_length);
2149        assert!(!selection.reversed);
2150
2151        let selected_text = rendered.text_for_range(selection.start..selection.end);
2152        assert_eq!(
2153            selected_text,
2154            "Hello world\nThis is a test\nwith multiple lines"
2155        );
2156    }
2157
2158    #[test]
2159    fn test_escape() {
2160        assert_eq!(Markdown::escape("hello `world`"), "hello \\`world\\`");
2161        assert_eq!(
2162            Markdown::escape("hello\n    cool world"),
2163            "hello\n\ncool world"
2164        );
2165    }
2166
2167    #[track_caller]
2168    fn assert_mappings(rendered: &RenderedText, expected: Vec<Vec<(usize, usize)>>) {
2169        assert_eq!(rendered.lines.len(), expected.len(), "line count mismatch");
2170        for (line_ix, line_mappings) in expected.into_iter().enumerate() {
2171            let line = &rendered.lines[line_ix];
2172
2173            assert!(
2174                line.source_mappings.windows(2).all(|mappings| {
2175                    mappings[0].source_index < mappings[1].source_index
2176                        && mappings[0].rendered_index < mappings[1].rendered_index
2177                }),
2178                "line {} has duplicate mappings: {:?}",
2179                line_ix,
2180                line.source_mappings
2181            );
2182
2183            for (rendered_ix, source_ix) in line_mappings {
2184                assert_eq!(
2185                    line.source_index_for_rendered_index(rendered_ix),
2186                    source_ix,
2187                    "line {}, rendered_ix {}",
2188                    line_ix,
2189                    rendered_ix
2190                );
2191
2192                assert_eq!(
2193                    line.rendered_index_for_source_index(source_ix),
2194                    rendered_ix,
2195                    "line {}, source_ix {}",
2196                    line_ix,
2197                    source_ix
2198                );
2199            }
2200        }
2201    }
2202}