markdown.rs

   1pub mod html;
   2mod mermaid;
   3pub mod parser;
   4mod path_range;
   5
   6use base64::Engine as _;
   7use futures::FutureExt as _;
   8use gpui::EdgesRefinement;
   9use gpui::HitboxBehavior;
  10use gpui::UnderlineStyle;
  11use language::LanguageName;
  12
  13use log::Level;
  14use mermaid::{
  15    MermaidState, ParsedMarkdownMermaidDiagram, extract_mermaid_diagrams, render_mermaid_diagram,
  16};
  17pub use path_range::{LineCol, PathWithRange};
  18use settings::Settings as _;
  19use theme_settings::ThemeSettings;
  20use ui::Checkbox;
  21use ui::CopyButton;
  22
  23use std::borrow::Cow;
  24use std::collections::BTreeMap;
  25use std::iter;
  26use std::mem;
  27use std::ops::Range;
  28use std::path::Path;
  29use std::rc::Rc;
  30use std::sync::Arc;
  31use std::time::Duration;
  32
  33use collections::{HashMap, HashSet};
  34use gpui::{
  35    AnyElement, App, BorderStyle, Bounds, ClipboardItem, CursorStyle, DispatchPhase, Edges, Entity,
  36    FocusHandle, Focusable, FontStyle, FontWeight, GlobalElementId, Hitbox, Hsla, Image,
  37    ImageFormat, ImageSource, KeyContext, Length, MouseButton, MouseDownEvent, MouseEvent,
  38    MouseMoveEvent, MouseUpEvent, Point, ScrollHandle, Stateful, StrikethroughStyle,
  39    StyleRefinement, StyledText, Task, TextAlign, TextLayout, TextRun, TextStyle,
  40    TextStyleRefinement, actions, img, point, quad,
  41};
  42use language::{CharClassifier, Language, LanguageRegistry, Rope};
  43use parser::CodeBlockMetadata;
  44use parser::{
  45    MarkdownEvent, MarkdownTag, MarkdownTagEnd, parse_links_only, parse_markdown_with_options,
  46};
  47use pulldown_cmark::Alignment;
  48use sum_tree::TreeMap;
  49use theme::SyntaxTheme;
  50use ui::{ScrollAxes, Scrollbars, WithScrollbar, prelude::*};
  51use util::ResultExt;
  52
  53use crate::parser::CodeBlockKind;
  54
  55/// A callback function that can be used to customize the style of links based on the destination URL.
  56/// If the callback returns `None`, the default link style will be used.
  57type LinkStyleCallback = Rc<dyn Fn(&str, &App) -> Option<TextStyleRefinement>>;
  58type SourceClickCallback = Box<dyn Fn(usize, usize, &mut Window, &mut App) -> bool>;
  59type CheckboxToggleCallback = Rc<dyn Fn(Range<usize>, bool, &mut Window, &mut App)>;
  60/// Defines custom style refinements for each heading level (H1-H6)
  61#[derive(Clone, Default)]
  62pub struct HeadingLevelStyles {
  63    pub h1: Option<TextStyleRefinement>,
  64    pub h2: Option<TextStyleRefinement>,
  65    pub h3: Option<TextStyleRefinement>,
  66    pub h4: Option<TextStyleRefinement>,
  67    pub h5: Option<TextStyleRefinement>,
  68    pub h6: Option<TextStyleRefinement>,
  69}
  70
  71#[derive(Clone)]
  72pub struct MarkdownStyle {
  73    pub base_text_style: TextStyle,
  74    pub container_style: StyleRefinement,
  75    pub code_block: StyleRefinement,
  76    pub code_block_overflow_x_scroll: bool,
  77    pub inline_code: TextStyleRefinement,
  78    pub block_quote: TextStyleRefinement,
  79    pub link: TextStyleRefinement,
  80    pub link_callback: Option<LinkStyleCallback>,
  81    pub rule_color: Hsla,
  82    pub block_quote_border_color: Hsla,
  83    pub syntax: Arc<SyntaxTheme>,
  84    pub selection_background_color: Hsla,
  85    pub heading: StyleRefinement,
  86    pub heading_level_styles: Option<HeadingLevelStyles>,
  87    pub height_is_multiple_of_line_height: bool,
  88    pub prevent_mouse_interaction: bool,
  89    pub table_columns_min_size: bool,
  90}
  91
  92impl Default for MarkdownStyle {
  93    fn default() -> Self {
  94        Self {
  95            base_text_style: Default::default(),
  96            container_style: Default::default(),
  97            code_block: Default::default(),
  98            code_block_overflow_x_scroll: false,
  99            inline_code: Default::default(),
 100            block_quote: Default::default(),
 101            link: Default::default(),
 102            link_callback: None,
 103            rule_color: Default::default(),
 104            block_quote_border_color: Default::default(),
 105            syntax: Arc::new(SyntaxTheme::default()),
 106            selection_background_color: Default::default(),
 107            heading: Default::default(),
 108            heading_level_styles: None,
 109            height_is_multiple_of_line_height: false,
 110            prevent_mouse_interaction: false,
 111            table_columns_min_size: false,
 112        }
 113    }
 114}
 115
 116pub enum MarkdownFont {
 117    Agent,
 118    Editor,
 119}
 120
 121impl MarkdownStyle {
 122    pub fn themed(font: MarkdownFont, window: &Window, cx: &App) -> Self {
 123        let theme_settings = ThemeSettings::get_global(cx);
 124        let colors = cx.theme().colors();
 125
 126        let buffer_font_weight = theme_settings.buffer_font.weight;
 127        let (buffer_font_size, ui_font_size) = match font {
 128            MarkdownFont::Agent => (
 129                theme_settings.agent_buffer_font_size(cx),
 130                theme_settings.agent_ui_font_size(cx),
 131            ),
 132            MarkdownFont::Editor => (
 133                theme_settings.buffer_font_size(cx),
 134                theme_settings.ui_font_size(cx),
 135            ),
 136        };
 137
 138        let text_color = colors.text;
 139
 140        let mut text_style = window.text_style();
 141        let line_height = buffer_font_size * 1.75;
 142
 143        text_style.refine(&TextStyleRefinement {
 144            font_family: Some(theme_settings.ui_font.family.clone()),
 145            font_fallbacks: theme_settings.ui_font.fallbacks.clone(),
 146            font_features: Some(theme_settings.ui_font.features.clone()),
 147            font_size: Some(ui_font_size.into()),
 148            line_height: Some(line_height.into()),
 149            color: Some(text_color),
 150            ..Default::default()
 151        });
 152
 153        MarkdownStyle {
 154            base_text_style: text_style.clone(),
 155            syntax: cx.theme().syntax().clone(),
 156            selection_background_color: colors.element_selection_background,
 157            rule_color: colors.border,
 158            block_quote_border_color: colors.border,
 159            code_block_overflow_x_scroll: true,
 160            heading_level_styles: Some(HeadingLevelStyles {
 161                h1: Some(TextStyleRefinement {
 162                    font_size: Some(rems(1.15).into()),
 163                    ..Default::default()
 164                }),
 165                h2: Some(TextStyleRefinement {
 166                    font_size: Some(rems(1.1).into()),
 167                    ..Default::default()
 168                }),
 169                h3: Some(TextStyleRefinement {
 170                    font_size: Some(rems(1.05).into()),
 171                    ..Default::default()
 172                }),
 173                h4: Some(TextStyleRefinement {
 174                    font_size: Some(rems(1.).into()),
 175                    ..Default::default()
 176                }),
 177                h5: Some(TextStyleRefinement {
 178                    font_size: Some(rems(0.95).into()),
 179                    ..Default::default()
 180                }),
 181                h6: Some(TextStyleRefinement {
 182                    font_size: Some(rems(0.875).into()),
 183                    ..Default::default()
 184                }),
 185            }),
 186            code_block: StyleRefinement {
 187                padding: EdgesRefinement {
 188                    top: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 189                    left: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 190                    right: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 191                    bottom: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 192                },
 193                margin: EdgesRefinement {
 194                    top: Some(Length::Definite(px(8.).into())),
 195                    left: Some(Length::Definite(px(0.).into())),
 196                    right: Some(Length::Definite(px(0.).into())),
 197                    bottom: Some(Length::Definite(px(12.).into())),
 198                },
 199                border_style: Some(BorderStyle::Solid),
 200                border_widths: EdgesRefinement {
 201                    top: Some(AbsoluteLength::Pixels(px(1.))),
 202                    left: Some(AbsoluteLength::Pixels(px(1.))),
 203                    right: Some(AbsoluteLength::Pixels(px(1.))),
 204                    bottom: Some(AbsoluteLength::Pixels(px(1.))),
 205                },
 206                border_color: Some(colors.border_variant),
 207                background: Some(colors.editor_background.into()),
 208                text: TextStyleRefinement {
 209                    font_family: Some(theme_settings.buffer_font.family.clone()),
 210                    font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 211                    font_features: Some(theme_settings.buffer_font.features.clone()),
 212                    font_size: Some(buffer_font_size.into()),
 213                    font_weight: Some(buffer_font_weight),
 214                    ..Default::default()
 215                },
 216                ..Default::default()
 217            },
 218            inline_code: TextStyleRefinement {
 219                font_family: Some(theme_settings.buffer_font.family.clone()),
 220                font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 221                font_features: Some(theme_settings.buffer_font.features.clone()),
 222                font_size: Some(buffer_font_size.into()),
 223                font_weight: Some(buffer_font_weight),
 224                background_color: Some(colors.editor_foreground.opacity(0.08)),
 225                ..Default::default()
 226            },
 227            link: TextStyleRefinement {
 228                background_color: Some(colors.editor_foreground.opacity(0.025)),
 229                color: Some(colors.text_accent),
 230                underline: Some(UnderlineStyle {
 231                    color: Some(colors.text_accent.opacity(0.5)),
 232                    thickness: px(1.),
 233                    ..Default::default()
 234                }),
 235                ..Default::default()
 236            },
 237            ..Default::default()
 238        }
 239    }
 240
 241    pub fn with_muted_text(mut self, cx: &App) -> Self {
 242        let colors = cx.theme().colors();
 243        self.base_text_style.color = colors.text_muted;
 244        self
 245    }
 246}
 247
 248pub struct Markdown {
 249    source: SharedString,
 250    selection: Selection,
 251    pressed_link: Option<RenderedLink>,
 252    pressed_footnote_ref: Option<RenderedFootnoteRef>,
 253    autoscroll_request: Option<usize>,
 254    active_root_block: Option<usize>,
 255    parsed_markdown: ParsedMarkdown,
 256    images_by_source_offset: HashMap<usize, Arc<Image>>,
 257    should_reparse: bool,
 258    pending_parse: Option<Task<()>>,
 259    focus_handle: FocusHandle,
 260    language_registry: Option<Arc<LanguageRegistry>>,
 261    fallback_code_block_language: Option<LanguageName>,
 262    options: MarkdownOptions,
 263    mermaid_state: MermaidState,
 264    copied_code_blocks: HashSet<ElementId>,
 265    code_block_scroll_handles: BTreeMap<usize, ScrollHandle>,
 266    context_menu_selected_text: Option<String>,
 267    search_highlights: Vec<Range<usize>>,
 268    active_search_highlight: Option<usize>,
 269}
 270
 271#[derive(Clone, Copy, Default)]
 272pub struct MarkdownOptions {
 273    pub parse_links_only: bool,
 274    pub parse_html: bool,
 275    pub render_mermaid_diagrams: bool,
 276    pub parse_heading_slugs: bool,
 277}
 278
 279#[derive(Clone, Copy, PartialEq, Eq)]
 280pub enum CopyButtonVisibility {
 281    Hidden,
 282    AlwaysVisible,
 283    VisibleOnHover,
 284}
 285
 286pub enum CodeBlockRenderer {
 287    Default {
 288        copy_button_visibility: CopyButtonVisibility,
 289        border: bool,
 290    },
 291    Custom {
 292        render: CodeBlockRenderFn,
 293        /// A function that can modify the parent container after the code block
 294        /// content has been appended as a child element.
 295        transform: Option<CodeBlockTransformFn>,
 296    },
 297}
 298
 299pub type CodeBlockRenderFn = Arc<
 300    dyn Fn(
 301        &CodeBlockKind,
 302        &ParsedMarkdown,
 303        Range<usize>,
 304        CodeBlockMetadata,
 305        &mut Window,
 306        &App,
 307    ) -> Div,
 308>;
 309
 310pub type CodeBlockTransformFn =
 311    Arc<dyn Fn(AnyDiv, Range<usize>, CodeBlockMetadata, &mut Window, &App) -> AnyDiv>;
 312
 313actions!(
 314    markdown,
 315    [
 316        /// Copies the selected text to the clipboard.
 317        Copy,
 318        /// Copies the selected text as markdown to the clipboard.
 319        CopyAsMarkdown
 320    ]
 321);
 322
 323enum EscapeAction {
 324    PassThrough,
 325    Nbsp(usize),
 326    DoubleNewline,
 327    PrefixBackslash,
 328}
 329
 330impl EscapeAction {
 331    fn output_len(&self) -> usize {
 332        match self {
 333            Self::PassThrough => 1,
 334            Self::Nbsp(count) => count * '\u{00A0}'.len_utf8(),
 335            Self::DoubleNewline => 2,
 336            Self::PrefixBackslash => 2,
 337        }
 338    }
 339
 340    fn write_to(&self, c: char, output: &mut String) {
 341        match self {
 342            Self::PassThrough => output.push(c),
 343            Self::Nbsp(count) => {
 344                for _ in 0..*count {
 345                    output.push('\u{00A0}');
 346                }
 347            }
 348            Self::DoubleNewline => {
 349                output.push('\n');
 350                output.push('\n');
 351            }
 352            Self::PrefixBackslash => {
 353                // '\\' is a single backslash in Rust, e.g. '|' -> '\|'
 354                output.push('\\');
 355                output.push(c);
 356            }
 357        }
 358    }
 359}
 360
 361// Valid to operate on raw bytes since multi-byte UTF-8
 362// sequences never contain ASCII-range bytes.
 363struct MarkdownEscaper {
 364    in_leading_whitespace: bool,
 365}
 366
 367impl MarkdownEscaper {
 368    const TAB_SIZE: usize = 4;
 369
 370    fn new() -> Self {
 371        Self {
 372            in_leading_whitespace: true,
 373        }
 374    }
 375
 376    fn next(&mut self, byte: u8) -> EscapeAction {
 377        let action = if self.in_leading_whitespace && byte == b'\t' {
 378            EscapeAction::Nbsp(Self::TAB_SIZE)
 379        } else if self.in_leading_whitespace && byte == b' ' {
 380            EscapeAction::Nbsp(1)
 381        } else if byte == b'\n' {
 382            EscapeAction::DoubleNewline
 383        } else if byte.is_ascii_punctuation() {
 384            EscapeAction::PrefixBackslash
 385        } else {
 386            EscapeAction::PassThrough
 387        };
 388
 389        self.in_leading_whitespace =
 390            byte == b'\n' || (self.in_leading_whitespace && (byte == b' ' || byte == b'\t'));
 391        action
 392    }
 393}
 394
 395impl Markdown {
 396    pub fn new(
 397        source: SharedString,
 398        language_registry: Option<Arc<LanguageRegistry>>,
 399        fallback_code_block_language: Option<LanguageName>,
 400        cx: &mut Context<Self>,
 401    ) -> Self {
 402        Self::new_with_options(
 403            source,
 404            language_registry,
 405            fallback_code_block_language,
 406            MarkdownOptions::default(),
 407            cx,
 408        )
 409    }
 410
 411    pub fn new_with_options(
 412        source: SharedString,
 413        language_registry: Option<Arc<LanguageRegistry>>,
 414        fallback_code_block_language: Option<LanguageName>,
 415        options: MarkdownOptions,
 416        cx: &mut Context<Self>,
 417    ) -> Self {
 418        let focus_handle = cx.focus_handle();
 419        let mut this = Self {
 420            source,
 421            selection: Selection::default(),
 422            pressed_link: None,
 423            pressed_footnote_ref: None,
 424            autoscroll_request: None,
 425            active_root_block: None,
 426            should_reparse: false,
 427            images_by_source_offset: Default::default(),
 428            parsed_markdown: ParsedMarkdown::default(),
 429            pending_parse: None,
 430            focus_handle,
 431            language_registry,
 432            fallback_code_block_language,
 433            options,
 434            mermaid_state: MermaidState::default(),
 435            copied_code_blocks: HashSet::default(),
 436            code_block_scroll_handles: BTreeMap::default(),
 437            context_menu_selected_text: None,
 438            search_highlights: Vec::new(),
 439            active_search_highlight: None,
 440        };
 441        this.parse(cx);
 442        this
 443    }
 444
 445    pub fn new_text(source: SharedString, cx: &mut Context<Self>) -> Self {
 446        Self::new_with_options(
 447            source,
 448            None,
 449            None,
 450            MarkdownOptions {
 451                parse_links_only: true,
 452                ..Default::default()
 453            },
 454            cx,
 455        )
 456    }
 457
 458    fn code_block_scroll_handle(&mut self, id: usize) -> ScrollHandle {
 459        self.code_block_scroll_handles
 460            .entry(id)
 461            .or_insert_with(ScrollHandle::new)
 462            .clone()
 463    }
 464
 465    fn retain_code_block_scroll_handles(&mut self, ids: &HashSet<usize>) {
 466        self.code_block_scroll_handles
 467            .retain(|id, _| ids.contains(id));
 468    }
 469
 470    fn clear_code_block_scroll_handles(&mut self) {
 471        self.code_block_scroll_handles.clear();
 472    }
 473
 474    fn autoscroll_code_block(&self, source_index: usize, cursor_position: Point<Pixels>) {
 475        let Some((_, scroll_handle)) = self
 476            .code_block_scroll_handles
 477            .range(..=source_index)
 478            .next_back()
 479        else {
 480            return;
 481        };
 482
 483        let bounds = scroll_handle.bounds();
 484        if cursor_position.y < bounds.top() || cursor_position.y > bounds.bottom() {
 485            return;
 486        }
 487
 488        let horizontal_delta = if cursor_position.x < bounds.left() {
 489            bounds.left() - cursor_position.x
 490        } else if cursor_position.x > bounds.right() {
 491            bounds.right() - cursor_position.x
 492        } else {
 493            return;
 494        };
 495
 496        let offset = scroll_handle.offset();
 497        scroll_handle.set_offset(point(offset.x + horizontal_delta, offset.y));
 498    }
 499
 500    pub fn is_parsing(&self) -> bool {
 501        self.pending_parse.is_some()
 502    }
 503
 504    pub fn scroll_to_heading(&mut self, slug: &str, cx: &mut Context<Self>) -> Option<usize> {
 505        if let Some(source_index) = self.parsed_markdown.heading_slugs.get(slug).copied() {
 506            self.autoscroll_request = Some(source_index);
 507            cx.notify();
 508            Some(source_index)
 509        } else {
 510            None
 511        }
 512    }
 513
 514    pub fn source(&self) -> &str {
 515        &self.source
 516    }
 517
 518    pub fn append(&mut self, text: &str, cx: &mut Context<Self>) {
 519        self.source = SharedString::new(self.source.to_string() + text);
 520        self.parse(cx);
 521    }
 522
 523    pub fn replace(&mut self, source: impl Into<SharedString>, cx: &mut Context<Self>) {
 524        self.source = source.into();
 525        self.parse(cx);
 526    }
 527
 528    pub fn request_autoscroll_to_source_index(
 529        &mut self,
 530        source_index: usize,
 531        cx: &mut Context<Self>,
 532    ) {
 533        self.autoscroll_request = Some(source_index);
 534        cx.refresh_windows();
 535    }
 536
 537    fn footnote_definition_content_start(&self, label: &SharedString) -> Option<usize> {
 538        self.parsed_markdown
 539            .footnote_definitions
 540            .get(label)
 541            .copied()
 542    }
 543
 544    pub fn set_active_root_for_source_index(
 545        &mut self,
 546        source_index: Option<usize>,
 547        cx: &mut Context<Self>,
 548    ) {
 549        let active_root_block =
 550            source_index.and_then(|index| self.parsed_markdown.root_block_for_source_index(index));
 551        if self.active_root_block == active_root_block {
 552            return;
 553        }
 554
 555        self.active_root_block = active_root_block;
 556        cx.notify();
 557    }
 558
 559    pub fn reset(&mut self, source: SharedString, cx: &mut Context<Self>) {
 560        if source == self.source() {
 561            return;
 562        }
 563        self.source = source;
 564        self.selection = Selection::default();
 565        self.autoscroll_request = None;
 566        self.pending_parse = None;
 567        self.should_reparse = false;
 568        self.search_highlights.clear();
 569        self.active_search_highlight = None;
 570        // Don't clear parsed_markdown here - keep existing content visible until new parse completes
 571        self.parse(cx);
 572    }
 573
 574    #[cfg(any(test, feature = "test-support"))]
 575    pub fn parsed_markdown(&self) -> &ParsedMarkdown {
 576        &self.parsed_markdown
 577    }
 578
 579    pub fn escape(s: &str) -> Cow<'_, str> {
 580        let output_len: usize = {
 581            let mut escaper = MarkdownEscaper::new();
 582            s.bytes().map(|byte| escaper.next(byte).output_len()).sum()
 583        };
 584
 585        if output_len == s.len() {
 586            return s.into();
 587        }
 588
 589        let mut escaper = MarkdownEscaper::new();
 590        let mut output = String::with_capacity(output_len);
 591        for c in s.chars() {
 592            escaper.next(c as u8).write_to(c, &mut output);
 593        }
 594        output.into()
 595    }
 596
 597    pub fn selected_text(&self) -> Option<String> {
 598        if self.selection.end <= self.selection.start {
 599            None
 600        } else {
 601            Some(self.source[self.selection.start..self.selection.end].to_string())
 602        }
 603    }
 604
 605    pub fn set_search_highlights(
 606        &mut self,
 607        highlights: Vec<Range<usize>>,
 608        active: Option<usize>,
 609        cx: &mut Context<Self>,
 610    ) {
 611        self.search_highlights = highlights;
 612        self.active_search_highlight = active;
 613        cx.notify();
 614    }
 615
 616    pub fn clear_search_highlights(&mut self, cx: &mut Context<Self>) {
 617        if !self.search_highlights.is_empty() || self.active_search_highlight.is_some() {
 618            self.search_highlights.clear();
 619            self.active_search_highlight = None;
 620            cx.notify();
 621        }
 622    }
 623
 624    pub fn set_active_search_highlight(&mut self, active: Option<usize>, cx: &mut Context<Self>) {
 625        if self.active_search_highlight != active {
 626            self.active_search_highlight = active;
 627            cx.notify();
 628        }
 629    }
 630
 631    pub fn search_highlights(&self) -> &[Range<usize>] {
 632        &self.search_highlights
 633    }
 634
 635    pub fn active_search_highlight(&self) -> Option<usize> {
 636        self.active_search_highlight
 637    }
 638
 639    fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
 640        if self.selection.end <= self.selection.start {
 641            return;
 642        }
 643        let text = text.text_for_range(self.selection.start..self.selection.end);
 644        cx.write_to_clipboard(ClipboardItem::new_string(text));
 645    }
 646
 647    fn copy_as_markdown(&mut self, _: &mut Window, cx: &mut Context<Self>) {
 648        if let Some(text) = self.context_menu_selected_text.take() {
 649            cx.write_to_clipboard(ClipboardItem::new_string(text));
 650            return;
 651        }
 652        if self.selection.end <= self.selection.start {
 653            return;
 654        }
 655        let text = self.source[self.selection.start..self.selection.end].to_string();
 656        cx.write_to_clipboard(ClipboardItem::new_string(text));
 657    }
 658
 659    fn capture_selection_for_context_menu(&mut self) {
 660        self.context_menu_selected_text = self.selected_text();
 661    }
 662
 663    fn parse(&mut self, cx: &mut Context<Self>) {
 664        if self.source.is_empty() {
 665            self.should_reparse = false;
 666            self.pending_parse.take();
 667            self.parsed_markdown = ParsedMarkdown {
 668                source: self.source.clone(),
 669                ..Default::default()
 670            };
 671            self.active_root_block = None;
 672            self.images_by_source_offset.clear();
 673            self.mermaid_state.clear();
 674            cx.notify();
 675            cx.refresh_windows();
 676            return;
 677        }
 678
 679        if self.pending_parse.is_some() {
 680            self.should_reparse = true;
 681            return;
 682        }
 683        self.should_reparse = false;
 684        self.pending_parse = Some(self.start_background_parse(cx));
 685    }
 686
 687    fn start_background_parse(&self, cx: &Context<Self>) -> Task<()> {
 688        let source = self.source.clone();
 689        let should_parse_links_only = self.options.parse_links_only;
 690        let should_parse_html = self.options.parse_html;
 691        let should_render_mermaid_diagrams = self.options.render_mermaid_diagrams;
 692        let should_parse_heading_slugs = self.options.parse_heading_slugs;
 693        let language_registry = self.language_registry.clone();
 694        let fallback = self.fallback_code_block_language.clone();
 695
 696        let parsed = cx.background_spawn(async move {
 697            if should_parse_links_only {
 698                return (
 699                    ParsedMarkdown {
 700                        events: Arc::from(parse_links_only(source.as_ref())),
 701                        source,
 702                        languages_by_name: TreeMap::default(),
 703                        languages_by_path: TreeMap::default(),
 704                        root_block_starts: Arc::default(),
 705                        html_blocks: BTreeMap::default(),
 706                        mermaid_diagrams: BTreeMap::default(),
 707                        heading_slugs: HashMap::default(),
 708                        footnote_definitions: HashMap::default(),
 709                    },
 710                    Default::default(),
 711                );
 712            }
 713
 714            let parsed =
 715                parse_markdown_with_options(&source, should_parse_html, should_parse_heading_slugs);
 716            let events = parsed.events;
 717            let language_names = parsed.language_names;
 718            let paths = parsed.language_paths;
 719            let root_block_starts = parsed.root_block_starts;
 720            let html_blocks = parsed.html_blocks;
 721            let heading_slugs = parsed.heading_slugs;
 722            let footnote_definitions = parsed.footnote_definitions;
 723            let mermaid_diagrams = if should_render_mermaid_diagrams {
 724                extract_mermaid_diagrams(&source, &events)
 725            } else {
 726                BTreeMap::default()
 727            };
 728            let mut images_by_source_offset = HashMap::default();
 729            let mut languages_by_name = TreeMap::default();
 730            let mut languages_by_path = TreeMap::default();
 731            if let Some(registry) = language_registry.as_ref() {
 732                for name in language_names {
 733                    let language = if !name.is_empty() {
 734                        registry.language_for_name_or_extension(&name).left_future()
 735                    } else if let Some(fallback) = &fallback {
 736                        registry.language_for_name(fallback.as_ref()).right_future()
 737                    } else {
 738                        continue;
 739                    };
 740                    if let Ok(language) = language.await {
 741                        languages_by_name.insert(name, language);
 742                    }
 743                }
 744
 745                for path in paths {
 746                    if let Ok(language) = registry
 747                        .load_language_for_file_path(Path::new(path.as_ref()))
 748                        .await
 749                    {
 750                        languages_by_path.insert(path, language);
 751                    }
 752                }
 753            }
 754
 755            for (range, event) in &events {
 756                if let MarkdownEvent::Start(MarkdownTag::Image { dest_url, .. }) = event
 757                    && let Some(data_url) = dest_url.strip_prefix("data:")
 758                {
 759                    let Some((mime_info, data)) = data_url.split_once(',') else {
 760                        continue;
 761                    };
 762                    let Some((mime_type, encoding)) = mime_info.split_once(';') else {
 763                        continue;
 764                    };
 765                    let Some(format) = ImageFormat::from_mime_type(mime_type) else {
 766                        continue;
 767                    };
 768                    let is_base64 = encoding == "base64";
 769                    if is_base64
 770                        && let Some(bytes) = base64::prelude::BASE64_STANDARD
 771                            .decode(data)
 772                            .log_with_level(Level::Debug)
 773                    {
 774                        let image = Arc::new(Image::from_bytes(format, bytes));
 775                        images_by_source_offset.insert(range.start, image);
 776                    }
 777                }
 778            }
 779
 780            (
 781                ParsedMarkdown {
 782                    source,
 783                    events: Arc::from(events),
 784                    languages_by_name,
 785                    languages_by_path,
 786                    root_block_starts: Arc::from(root_block_starts),
 787                    html_blocks,
 788                    mermaid_diagrams,
 789                    heading_slugs,
 790                    footnote_definitions,
 791                },
 792                images_by_source_offset,
 793            )
 794        });
 795
 796        cx.spawn(async move |this, cx| {
 797            let (parsed, images_by_source_offset) = parsed.await;
 798
 799            this.update(cx, |this, cx| {
 800                this.parsed_markdown = parsed;
 801                this.images_by_source_offset = images_by_source_offset;
 802                if this.active_root_block.is_some_and(|block_index| {
 803                    block_index >= this.parsed_markdown.root_block_starts.len()
 804                }) {
 805                    this.active_root_block = None;
 806                }
 807                if this.options.render_mermaid_diagrams {
 808                    let parsed_markdown = this.parsed_markdown.clone();
 809                    this.mermaid_state.update(&parsed_markdown, cx);
 810                } else {
 811                    this.mermaid_state.clear();
 812                }
 813                this.pending_parse.take();
 814                if this.should_reparse {
 815                    this.parse(cx);
 816                }
 817                cx.notify();
 818                cx.refresh_windows();
 819            })
 820            .ok();
 821        })
 822    }
 823}
 824
 825impl Focusable for Markdown {
 826    fn focus_handle(&self, _cx: &App) -> FocusHandle {
 827        self.focus_handle.clone()
 828    }
 829}
 830
 831#[derive(Debug, Default, Clone)]
 832enum SelectMode {
 833    #[default]
 834    Character,
 835    Word(Range<usize>),
 836    Line(Range<usize>),
 837    All,
 838}
 839
 840#[derive(Clone, Default)]
 841struct Selection {
 842    start: usize,
 843    end: usize,
 844    reversed: bool,
 845    pending: bool,
 846    mode: SelectMode,
 847}
 848
 849impl Selection {
 850    fn set_head(&mut self, head: usize, rendered_text: &RenderedText) {
 851        match &self.mode {
 852            SelectMode::Character => {
 853                if head < self.tail() {
 854                    if !self.reversed {
 855                        self.end = self.start;
 856                        self.reversed = true;
 857                    }
 858                    self.start = head;
 859                } else {
 860                    if self.reversed {
 861                        self.start = self.end;
 862                        self.reversed = false;
 863                    }
 864                    self.end = head;
 865                }
 866            }
 867            SelectMode::Word(original_range) | SelectMode::Line(original_range) => {
 868                let head_range = if matches!(self.mode, SelectMode::Word(_)) {
 869                    rendered_text.surrounding_word_range(head)
 870                } else {
 871                    rendered_text.surrounding_line_range(head)
 872                };
 873
 874                if head < original_range.start {
 875                    self.start = head_range.start;
 876                    self.end = original_range.end;
 877                    self.reversed = true;
 878                } else if head >= original_range.end {
 879                    self.start = original_range.start;
 880                    self.end = head_range.end;
 881                    self.reversed = false;
 882                } else {
 883                    self.start = original_range.start;
 884                    self.end = original_range.end;
 885                    self.reversed = false;
 886                }
 887            }
 888            SelectMode::All => {
 889                self.start = 0;
 890                self.end = rendered_text
 891                    .lines
 892                    .last()
 893                    .map(|line| line.source_end)
 894                    .unwrap_or(0);
 895                self.reversed = false;
 896            }
 897        }
 898    }
 899
 900    fn tail(&self) -> usize {
 901        if self.reversed { self.end } else { self.start }
 902    }
 903}
 904
 905#[derive(Debug, Clone, Default)]
 906pub struct ParsedMarkdown {
 907    pub source: SharedString,
 908    pub events: Arc<[(Range<usize>, MarkdownEvent)]>,
 909    pub languages_by_name: TreeMap<SharedString, Arc<Language>>,
 910    pub languages_by_path: TreeMap<Arc<str>, Arc<Language>>,
 911    pub root_block_starts: Arc<[usize]>,
 912    pub(crate) html_blocks: BTreeMap<usize, html::html_parser::ParsedHtmlBlock>,
 913    pub(crate) mermaid_diagrams: BTreeMap<usize, ParsedMarkdownMermaidDiagram>,
 914    pub heading_slugs: HashMap<SharedString, usize>,
 915    pub footnote_definitions: HashMap<SharedString, usize>,
 916}
 917
 918impl ParsedMarkdown {
 919    pub fn source(&self) -> &SharedString {
 920        &self.source
 921    }
 922
 923    pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
 924        &self.events
 925    }
 926
 927    pub fn root_block_starts(&self) -> &Arc<[usize]> {
 928        &self.root_block_starts
 929    }
 930
 931    pub fn root_block_for_source_index(&self, source_index: usize) -> Option<usize> {
 932        if self.root_block_starts.is_empty() {
 933            return None;
 934        }
 935
 936        let partition = self
 937            .root_block_starts
 938            .partition_point(|block_start| *block_start <= source_index);
 939
 940        Some(partition.saturating_sub(1))
 941    }
 942}
 943
 944pub enum AutoscrollBehavior {
 945    /// Propagate the request up the element tree for the nearest
 946    /// scrollable ancestor (e.g. `List`) to handle.
 947    Propagate,
 948    /// Directly control a specific scroll handle.
 949    Controlled(ScrollHandle),
 950}
 951
 952pub struct MarkdownElement {
 953    markdown: Entity<Markdown>,
 954    style: MarkdownStyle,
 955    code_block_renderer: CodeBlockRenderer,
 956    on_url_click: Option<Box<dyn Fn(SharedString, &mut Window, &mut App)>>,
 957    on_source_click: Option<SourceClickCallback>,
 958    on_checkbox_toggle: Option<CheckboxToggleCallback>,
 959    image_resolver: Option<Box<dyn Fn(&str) -> Option<ImageSource>>>,
 960    show_root_block_markers: bool,
 961    autoscroll: AutoscrollBehavior,
 962}
 963
 964impl MarkdownElement {
 965    pub fn new(markdown: Entity<Markdown>, style: MarkdownStyle) -> Self {
 966        Self {
 967            markdown,
 968            style,
 969            code_block_renderer: CodeBlockRenderer::Default {
 970                copy_button_visibility: CopyButtonVisibility::VisibleOnHover,
 971                border: false,
 972            },
 973            on_url_click: None,
 974            on_source_click: None,
 975            on_checkbox_toggle: None,
 976            image_resolver: None,
 977            show_root_block_markers: false,
 978            autoscroll: AutoscrollBehavior::Propagate,
 979        }
 980    }
 981
 982    #[cfg(any(test, feature = "test-support"))]
 983    pub fn rendered_text(
 984        markdown: Entity<Markdown>,
 985        cx: &mut gpui::VisualTestContext,
 986        style: impl FnOnce(&Window, &App) -> MarkdownStyle,
 987    ) -> String {
 988        use gpui::size;
 989
 990        let (text, _) = cx.draw(
 991            Default::default(),
 992            size(px(600.0), px(600.0)),
 993            |window, cx| Self::new(markdown, style(window, cx)),
 994        );
 995        text.text
 996            .lines
 997            .iter()
 998            .map(|line| line.layout.wrapped_text())
 999            .collect::<Vec<_>>()
1000            .join("\n")
1001    }
1002
1003    pub fn code_block_renderer(mut self, variant: CodeBlockRenderer) -> Self {
1004        self.code_block_renderer = variant;
1005        self
1006    }
1007
1008    pub fn on_url_click(
1009        mut self,
1010        handler: impl Fn(SharedString, &mut Window, &mut App) + 'static,
1011    ) -> Self {
1012        self.on_url_click = Some(Box::new(handler));
1013        self
1014    }
1015
1016    pub fn on_source_click(
1017        mut self,
1018        handler: impl Fn(usize, usize, &mut Window, &mut App) -> bool + 'static,
1019    ) -> Self {
1020        self.on_source_click = Some(Box::new(handler));
1021        self
1022    }
1023
1024    pub fn on_checkbox_toggle(
1025        mut self,
1026        handler: impl Fn(Range<usize>, bool, &mut Window, &mut App) + 'static,
1027    ) -> Self {
1028        self.on_checkbox_toggle = Some(Rc::new(handler));
1029        self
1030    }
1031
1032    pub fn image_resolver(
1033        mut self,
1034        resolver: impl Fn(&str) -> Option<ImageSource> + 'static,
1035    ) -> Self {
1036        self.image_resolver = Some(Box::new(resolver));
1037        self
1038    }
1039
1040    pub fn show_root_block_markers(mut self) -> Self {
1041        self.show_root_block_markers = true;
1042        self
1043    }
1044
1045    pub fn scroll_handle(mut self, scroll_handle: ScrollHandle) -> Self {
1046        self.autoscroll = AutoscrollBehavior::Controlled(scroll_handle);
1047        self
1048    }
1049
1050    fn push_markdown_image(
1051        &self,
1052        builder: &mut MarkdownElementBuilder,
1053        range: &Range<usize>,
1054        source: ImageSource,
1055        width: Option<DefiniteLength>,
1056        height: Option<DefiniteLength>,
1057    ) {
1058        let align = builder.text_style().text_align;
1059        builder.modify_current_div(|el| {
1060            let mut image_container = el.flex().flex_row().items_center();
1061
1062            image_container = match align {
1063                TextAlign::Left => image_container.justify_start(),
1064                TextAlign::Center => image_container.justify_center(),
1065                TextAlign::Right => image_container.justify_end(),
1066            };
1067
1068            image_container.child(
1069                img(source)
1070                    .max_w_full()
1071                    .when_some(height, |this, height| this.h(height))
1072                    .when_some(width, |this, width| this.w(width)),
1073            )
1074        });
1075        let _ = range;
1076    }
1077
1078    fn push_markdown_paragraph(
1079        &self,
1080        builder: &mut MarkdownElementBuilder,
1081        range: &Range<usize>,
1082        markdown_end: usize,
1083        text_align_override: Option<TextAlign>,
1084    ) {
1085        let align = text_align_override.unwrap_or(self.style.base_text_style.text_align);
1086        let mut paragraph = div().when(!self.style.height_is_multiple_of_line_height, |el| {
1087            el.mb_2().line_height(rems(1.3))
1088        });
1089
1090        paragraph = match align {
1091            TextAlign::Center => paragraph.text_center(),
1092            TextAlign::Left => paragraph.text_left(),
1093            TextAlign::Right => paragraph.text_right(),
1094        };
1095
1096        builder.push_text_style(TextStyleRefinement {
1097            text_align: Some(align),
1098            ..Default::default()
1099        });
1100        builder.push_div(paragraph, range, markdown_end);
1101    }
1102
1103    fn pop_markdown_paragraph(&self, builder: &mut MarkdownElementBuilder) {
1104        builder.pop_div();
1105        builder.pop_text_style();
1106    }
1107
1108    fn push_markdown_heading(
1109        &self,
1110        builder: &mut MarkdownElementBuilder,
1111        level: pulldown_cmark::HeadingLevel,
1112        range: &Range<usize>,
1113        markdown_end: usize,
1114        text_align_override: Option<TextAlign>,
1115    ) {
1116        let align = text_align_override.unwrap_or(self.style.base_text_style.text_align);
1117        let mut heading = div().mb_2();
1118        heading = apply_heading_style(heading, level, self.style.heading_level_styles.as_ref());
1119
1120        heading = match align {
1121            TextAlign::Center => heading.text_center(),
1122            TextAlign::Left => heading.text_left(),
1123            TextAlign::Right => heading.text_right(),
1124        };
1125
1126        let mut heading_style = self.style.heading.clone();
1127        let heading_text_style = heading_style.text_style().clone();
1128        heading.style().refine(&heading_style);
1129
1130        builder.push_text_style(TextStyleRefinement {
1131            text_align: Some(align),
1132            ..heading_text_style
1133        });
1134        builder.push_div(heading, range, markdown_end);
1135    }
1136
1137    fn pop_markdown_heading(&self, builder: &mut MarkdownElementBuilder) {
1138        builder.pop_div();
1139        builder.pop_text_style();
1140    }
1141
1142    fn push_markdown_block_quote(
1143        &self,
1144        builder: &mut MarkdownElementBuilder,
1145        range: &Range<usize>,
1146        markdown_end: usize,
1147    ) {
1148        builder.push_text_style(self.style.block_quote.clone());
1149        builder.push_div(
1150            div()
1151                .pl_4()
1152                .mb_2()
1153                .border_l_4()
1154                .border_color(self.style.block_quote_border_color),
1155            range,
1156            markdown_end,
1157        );
1158    }
1159
1160    fn pop_markdown_block_quote(&self, builder: &mut MarkdownElementBuilder) {
1161        builder.pop_div();
1162        builder.pop_text_style();
1163    }
1164
1165    fn push_markdown_list_item(
1166        &self,
1167        builder: &mut MarkdownElementBuilder,
1168        bullet: AnyElement,
1169        range: &Range<usize>,
1170        markdown_end: usize,
1171    ) {
1172        builder.push_div(
1173            div()
1174                .when(!self.style.height_is_multiple_of_line_height, |el| {
1175                    el.mb_1().gap_1().line_height(rems(1.3))
1176                })
1177                .h_flex()
1178                .items_start()
1179                .child(bullet),
1180            range,
1181            markdown_end,
1182        );
1183        // Without `w_0`, text doesn't wrap to the width of the container.
1184        builder.push_div(div().flex_1().w_0(), range, markdown_end);
1185    }
1186
1187    fn pop_markdown_list_item(&self, builder: &mut MarkdownElementBuilder) {
1188        builder.pop_div();
1189        builder.pop_div();
1190    }
1191
1192    fn paint_highlight_range(
1193        bounds: Bounds<Pixels>,
1194        start: usize,
1195        end: usize,
1196        color: Hsla,
1197        rendered_text: &RenderedText,
1198        window: &mut Window,
1199    ) {
1200        let start_pos = rendered_text.position_for_source_index(start);
1201        let end_pos = rendered_text.position_for_source_index(end);
1202        if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
1203            start_pos.zip(end_pos)
1204        {
1205            if start_position.y == end_position.y {
1206                window.paint_quad(quad(
1207                    Bounds::from_corners(
1208                        start_position,
1209                        point(end_position.x, end_position.y + end_line_height),
1210                    ),
1211                    Pixels::ZERO,
1212                    color,
1213                    Edges::default(),
1214                    Hsla::transparent_black(),
1215                    BorderStyle::default(),
1216                ));
1217            } else {
1218                window.paint_quad(quad(
1219                    Bounds::from_corners(
1220                        start_position,
1221                        point(bounds.right(), start_position.y + start_line_height),
1222                    ),
1223                    Pixels::ZERO,
1224                    color,
1225                    Edges::default(),
1226                    Hsla::transparent_black(),
1227                    BorderStyle::default(),
1228                ));
1229
1230                if end_position.y > start_position.y + start_line_height {
1231                    window.paint_quad(quad(
1232                        Bounds::from_corners(
1233                            point(bounds.left(), start_position.y + start_line_height),
1234                            point(bounds.right(), end_position.y),
1235                        ),
1236                        Pixels::ZERO,
1237                        color,
1238                        Edges::default(),
1239                        Hsla::transparent_black(),
1240                        BorderStyle::default(),
1241                    ));
1242                }
1243
1244                window.paint_quad(quad(
1245                    Bounds::from_corners(
1246                        point(bounds.left(), end_position.y),
1247                        point(end_position.x, end_position.y + end_line_height),
1248                    ),
1249                    Pixels::ZERO,
1250                    color,
1251                    Edges::default(),
1252                    Hsla::transparent_black(),
1253                    BorderStyle::default(),
1254                ));
1255            }
1256        }
1257    }
1258
1259    fn paint_selection(
1260        &self,
1261        bounds: Bounds<Pixels>,
1262        rendered_text: &RenderedText,
1263        window: &mut Window,
1264        cx: &mut App,
1265    ) {
1266        let selection = self.markdown.read(cx).selection.clone();
1267        Self::paint_highlight_range(
1268            bounds,
1269            selection.start,
1270            selection.end,
1271            self.style.selection_background_color,
1272            rendered_text,
1273            window,
1274        );
1275    }
1276
1277    fn paint_search_highlights(
1278        &self,
1279        bounds: Bounds<Pixels>,
1280        rendered_text: &RenderedText,
1281        window: &mut Window,
1282        cx: &mut App,
1283    ) {
1284        let markdown = self.markdown.read(cx);
1285        let active_index = markdown.active_search_highlight;
1286        let colors = cx.theme().colors();
1287
1288        for (i, highlight_range) in markdown.search_highlights.iter().enumerate() {
1289            let color = if Some(i) == active_index {
1290                colors.search_active_match_background
1291            } else {
1292                colors.search_match_background
1293            };
1294            Self::paint_highlight_range(
1295                bounds,
1296                highlight_range.start,
1297                highlight_range.end,
1298                color,
1299                rendered_text,
1300                window,
1301            );
1302        }
1303    }
1304
1305    fn paint_mouse_listeners(
1306        &mut self,
1307        hitbox: &Hitbox,
1308        rendered_text: &RenderedText,
1309        window: &mut Window,
1310        cx: &mut App,
1311    ) {
1312        if self.style.prevent_mouse_interaction {
1313            return;
1314        }
1315
1316        let is_hovering_clickable = hitbox.is_hovered(window)
1317            && !self.markdown.read(cx).selection.pending
1318            && rendered_text
1319                .source_index_for_position(window.mouse_position())
1320                .ok()
1321                .is_some_and(|source_index| {
1322                    rendered_text.link_for_source_index(source_index).is_some()
1323                        || rendered_text
1324                            .footnote_ref_for_source_index(source_index)
1325                            .is_some()
1326                });
1327
1328        if is_hovering_clickable {
1329            window.set_cursor_style(CursorStyle::PointingHand, hitbox);
1330        } else {
1331            window.set_cursor_style(CursorStyle::IBeam, hitbox);
1332        }
1333
1334        let on_open_url = self.on_url_click.take();
1335        let on_source_click = self.on_source_click.take();
1336
1337        self.on_mouse_event(window, cx, {
1338            let hitbox = hitbox.clone();
1339            move |markdown, event: &MouseDownEvent, phase, window, _| {
1340                if phase.capture()
1341                    && event.button == MouseButton::Right
1342                    && hitbox.is_hovered(window)
1343                {
1344                    // Capture selected text so it survives until menu item is clicked
1345                    markdown.capture_selection_for_context_menu();
1346                }
1347            }
1348        });
1349
1350        self.on_mouse_event(window, cx, {
1351            let rendered_text = rendered_text.clone();
1352            let hitbox = hitbox.clone();
1353            move |markdown, event: &MouseDownEvent, phase, window, cx| {
1354                if hitbox.is_hovered(window) {
1355                    if phase.bubble() {
1356                        let position_result =
1357                            rendered_text.source_index_for_position(event.position);
1358
1359                        if let Ok(source_index) = position_result {
1360                            if let Some(footnote_ref) =
1361                                rendered_text.footnote_ref_for_source_index(source_index)
1362                            {
1363                                markdown.pressed_footnote_ref = Some(footnote_ref.clone());
1364                            } else if let Some(link) =
1365                                rendered_text.link_for_source_index(source_index)
1366                            {
1367                                markdown.pressed_link = Some(link.clone());
1368                            }
1369                        }
1370
1371                        if markdown.pressed_footnote_ref.is_none()
1372                            && markdown.pressed_link.is_none()
1373                        {
1374                            let source_index = match position_result {
1375                                Ok(ix) | Err(ix) => ix,
1376                            };
1377                            if let Some(handler) = on_source_click.as_ref() {
1378                                let blocked = handler(source_index, event.click_count, window, cx);
1379                                if blocked {
1380                                    markdown.selection = Selection::default();
1381                                    markdown.pressed_link = None;
1382                                    window.prevent_default();
1383                                    cx.notify();
1384                                    return;
1385                                }
1386                            }
1387                            let (range, mode) = match event.click_count {
1388                                1 => {
1389                                    let range = source_index..source_index;
1390                                    (range, SelectMode::Character)
1391                                }
1392                                2 => {
1393                                    let range = rendered_text.surrounding_word_range(source_index);
1394                                    (range.clone(), SelectMode::Word(range))
1395                                }
1396                                3 => {
1397                                    let range = rendered_text.surrounding_line_range(source_index);
1398                                    (range.clone(), SelectMode::Line(range))
1399                                }
1400                                _ => {
1401                                    let range = 0..rendered_text
1402                                        .lines
1403                                        .last()
1404                                        .map(|line| line.source_end)
1405                                        .unwrap_or(0);
1406                                    (range, SelectMode::All)
1407                                }
1408                            };
1409                            markdown.selection = Selection {
1410                                start: range.start,
1411                                end: range.end,
1412                                reversed: false,
1413                                pending: true,
1414                                mode,
1415                            };
1416                            window.focus(&markdown.focus_handle, cx);
1417                        }
1418
1419                        window.prevent_default();
1420                        cx.notify();
1421                    }
1422                } else if phase.capture() && event.button == MouseButton::Left {
1423                    markdown.selection = Selection::default();
1424                    markdown.pressed_link = None;
1425                    cx.notify();
1426                }
1427            }
1428        });
1429        self.on_mouse_event(window, cx, {
1430            let rendered_text = rendered_text.clone();
1431            let hitbox = hitbox.clone();
1432            let was_hovering_clickable = is_hovering_clickable;
1433            move |markdown, event: &MouseMoveEvent, phase, window, cx| {
1434                if phase.capture() {
1435                    return;
1436                }
1437
1438                if markdown.selection.pending {
1439                    let source_index = match rendered_text.source_index_for_position(event.position)
1440                    {
1441                        Ok(ix) | Err(ix) => ix,
1442                    };
1443                    markdown.selection.set_head(source_index, &rendered_text);
1444                    markdown.autoscroll_code_block(source_index, event.position);
1445                    markdown.autoscroll_request = Some(source_index);
1446                    cx.notify();
1447                } else {
1448                    let is_hovering_clickable = hitbox.is_hovered(window)
1449                        && rendered_text
1450                            .source_index_for_position(event.position)
1451                            .ok()
1452                            .is_some_and(|source_index| {
1453                                rendered_text.link_for_source_index(source_index).is_some()
1454                                    || rendered_text
1455                                        .footnote_ref_for_source_index(source_index)
1456                                        .is_some()
1457                            });
1458                    if is_hovering_clickable != was_hovering_clickable {
1459                        cx.notify();
1460                    }
1461                }
1462            }
1463        });
1464        self.on_mouse_event(window, cx, {
1465            let rendered_text = rendered_text.clone();
1466            move |markdown, event: &MouseUpEvent, phase, window, cx| {
1467                if phase.bubble() {
1468                    let source_index = rendered_text.source_index_for_position(event.position).ok();
1469                    if let Some(pressed_footnote_ref) = markdown.pressed_footnote_ref.take()
1470                        && source_index
1471                            .and_then(|ix| rendered_text.footnote_ref_for_source_index(ix))
1472                            == Some(&pressed_footnote_ref)
1473                    {
1474                        if let Some(source_index) =
1475                            markdown.footnote_definition_content_start(&pressed_footnote_ref.label)
1476                        {
1477                            markdown.autoscroll_request = Some(source_index);
1478                            cx.notify();
1479                        }
1480                    } else if let Some(pressed_link) = markdown.pressed_link.take()
1481                        && source_index.and_then(|ix| rendered_text.link_for_source_index(ix))
1482                            == Some(&pressed_link)
1483                    {
1484                        if let Some(open_url) = on_open_url.as_ref() {
1485                            open_url(pressed_link.destination_url, window, cx);
1486                        } else {
1487                            cx.open_url(&pressed_link.destination_url);
1488                        }
1489                    }
1490                } else if markdown.selection.pending {
1491                    markdown.selection.pending = false;
1492                    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
1493                    {
1494                        let text = rendered_text
1495                            .text_for_range(markdown.selection.start..markdown.selection.end);
1496                        cx.write_to_primary(ClipboardItem::new_string(text))
1497                    }
1498                    cx.notify();
1499                }
1500            }
1501        });
1502    }
1503
1504    fn autoscroll(
1505        &self,
1506        rendered_text: &RenderedText,
1507        window: &mut Window,
1508        cx: &mut App,
1509    ) -> Option<()> {
1510        let autoscroll_index = self
1511            .markdown
1512            .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
1513        let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
1514
1515        match &self.autoscroll {
1516            AutoscrollBehavior::Controlled(scroll_handle) => {
1517                let viewport = scroll_handle.bounds();
1518                let margin = line_height * 3.;
1519                let top_goal = viewport.top() + margin;
1520                let bottom_goal = viewport.bottom() - margin;
1521                let current_offset = scroll_handle.offset();
1522
1523                let new_offset_y = if position.y < top_goal {
1524                    current_offset.y + (top_goal - position.y)
1525                } else if position.y + line_height > bottom_goal {
1526                    current_offset.y + (bottom_goal - (position.y + line_height))
1527                } else {
1528                    current_offset.y
1529                };
1530
1531                scroll_handle.set_offset(point(
1532                    current_offset.x,
1533                    new_offset_y.clamp(-scroll_handle.max_offset().y, Pixels::ZERO),
1534                ));
1535            }
1536            AutoscrollBehavior::Propagate => {
1537                let text_style = self.style.base_text_style.clone();
1538                let font_id = window.text_system().resolve_font(&text_style.font());
1539                let font_size = text_style.font_size.to_pixels(window.rem_size());
1540                let em_width = window.text_system().em_width(font_id, font_size).unwrap();
1541                window.request_autoscroll(Bounds::from_corners(
1542                    point(position.x - 3. * em_width, position.y - 3. * line_height),
1543                    point(position.x + 3. * em_width, position.y + 3. * line_height),
1544                ));
1545            }
1546        }
1547        Some(())
1548    }
1549
1550    fn on_mouse_event<T: MouseEvent>(
1551        &self,
1552        window: &mut Window,
1553        _cx: &mut App,
1554        mut f: impl 'static
1555        + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
1556    ) {
1557        window.on_mouse_event({
1558            let markdown = self.markdown.downgrade();
1559            move |event, phase, window, cx| {
1560                markdown
1561                    .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
1562                    .log_err();
1563            }
1564        });
1565    }
1566}
1567
1568impl Styled for MarkdownElement {
1569    fn style(&mut self) -> &mut StyleRefinement {
1570        &mut self.style.container_style
1571    }
1572}
1573
1574impl Element for MarkdownElement {
1575    type RequestLayoutState = RenderedMarkdown;
1576    type PrepaintState = Hitbox;
1577
1578    fn id(&self) -> Option<ElementId> {
1579        None
1580    }
1581
1582    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
1583        None
1584    }
1585
1586    fn request_layout(
1587        &mut self,
1588        _id: Option<&GlobalElementId>,
1589        _inspector_id: Option<&gpui::InspectorElementId>,
1590        window: &mut Window,
1591        cx: &mut App,
1592    ) -> (gpui::LayoutId, Self::RequestLayoutState) {
1593        let mut builder = MarkdownElementBuilder::new(
1594            &self.style.container_style,
1595            self.style.base_text_style.clone(),
1596            self.style.syntax.clone(),
1597        );
1598        let (parsed_markdown, images, active_root_block, render_mermaid_diagrams, mermaid_state) = {
1599            let markdown = self.markdown.read(cx);
1600            (
1601                markdown.parsed_markdown.clone(),
1602                markdown.images_by_source_offset.clone(),
1603                markdown.active_root_block,
1604                markdown.options.render_mermaid_diagrams,
1605                markdown.mermaid_state.clone(),
1606            )
1607        };
1608        let markdown_end = if let Some(last) = parsed_markdown.events.last() {
1609            last.0.end
1610        } else {
1611            0
1612        };
1613        let mut code_block_ids = HashSet::default();
1614
1615        let mut current_img_block_range: Option<Range<usize>> = None;
1616        let mut handled_html_block = false;
1617        let mut rendered_mermaid_block = false;
1618        for (index, (range, event)) in parsed_markdown.events.iter().enumerate() {
1619            // Skip alt text for images that rendered
1620            if let Some(current_img_block_range) = &current_img_block_range
1621                && current_img_block_range.end > range.end
1622            {
1623                continue;
1624            }
1625
1626            if handled_html_block {
1627                if let MarkdownEvent::End(MarkdownTagEnd::HtmlBlock) = event {
1628                    handled_html_block = false;
1629                } else {
1630                    continue;
1631                }
1632            }
1633
1634            if rendered_mermaid_block {
1635                if matches!(event, MarkdownEvent::End(MarkdownTagEnd::CodeBlock)) {
1636                    rendered_mermaid_block = false;
1637                }
1638                continue;
1639            }
1640
1641            match event {
1642                MarkdownEvent::RootStart => {
1643                    if self.show_root_block_markers {
1644                        builder.push_root_block(range, markdown_end);
1645                    }
1646                }
1647                MarkdownEvent::RootEnd(root_block_index) => {
1648                    if self.show_root_block_markers {
1649                        builder.pop_root_block(
1650                            active_root_block == Some(*root_block_index),
1651                            cx.theme().colors().border,
1652                            cx.theme().colors().border_variant,
1653                        );
1654                    }
1655                }
1656                MarkdownEvent::Start(tag) => {
1657                    match tag {
1658                        MarkdownTag::Image { dest_url, .. } => {
1659                            if let Some(image) = images.get(&range.start) {
1660                                current_img_block_range = Some(range.clone());
1661                                self.push_markdown_image(
1662                                    &mut builder,
1663                                    range,
1664                                    image.clone().into(),
1665                                    None,
1666                                    None,
1667                                );
1668                            } else if let Some(source) = self
1669                                .image_resolver
1670                                .as_ref()
1671                                .and_then(|resolve| resolve(dest_url.as_ref()))
1672                            {
1673                                current_img_block_range = Some(range.clone());
1674                                self.push_markdown_image(&mut builder, range, source, None, None);
1675                            }
1676                        }
1677                        MarkdownTag::Paragraph => {
1678                            self.push_markdown_paragraph(&mut builder, range, markdown_end, None);
1679                        }
1680                        MarkdownTag::Heading { level, .. } => {
1681                            self.push_markdown_heading(
1682                                &mut builder,
1683                                *level,
1684                                range,
1685                                markdown_end,
1686                                None,
1687                            );
1688                        }
1689                        MarkdownTag::BlockQuote => {
1690                            self.push_markdown_block_quote(&mut builder, range, markdown_end);
1691                        }
1692                        MarkdownTag::CodeBlock { kind, .. } => {
1693                            if render_mermaid_diagrams
1694                                && let Some(mermaid_diagram) =
1695                                    parsed_markdown.mermaid_diagrams.get(&range.start)
1696                            {
1697                                builder.push_sourced_element(
1698                                    mermaid_diagram.content_range.clone(),
1699                                    render_mermaid_diagram(
1700                                        mermaid_diagram,
1701                                        &mermaid_state,
1702                                        &self.style,
1703                                    ),
1704                                );
1705                                rendered_mermaid_block = true;
1706                                continue;
1707                            }
1708
1709                            let language = match kind {
1710                                CodeBlockKind::Fenced => None,
1711                                CodeBlockKind::FencedLang(language) => {
1712                                    parsed_markdown.languages_by_name.get(language).cloned()
1713                                }
1714                                CodeBlockKind::FencedSrc(path_range) => parsed_markdown
1715                                    .languages_by_path
1716                                    .get(&path_range.path)
1717                                    .cloned(),
1718                                _ => None,
1719                            };
1720
1721                            let is_indented = matches!(kind, CodeBlockKind::Indented);
1722                            let scroll_handle = if self.style.code_block_overflow_x_scroll {
1723                                code_block_ids.insert(range.start);
1724                                Some(self.markdown.update(cx, |markdown, _| {
1725                                    markdown.code_block_scroll_handle(range.start)
1726                                }))
1727                            } else {
1728                                None
1729                            };
1730
1731                            match (&self.code_block_renderer, is_indented) {
1732                                (CodeBlockRenderer::Default { .. }, _) | (_, true) => {
1733                                    // This is a parent container that we can position the copy button inside.
1734                                    let parent_container =
1735                                        div().group("code_block").relative().w_full();
1736
1737                                    let mut parent_container: AnyDiv = if let Some(scroll_handle) =
1738                                        scroll_handle.as_ref()
1739                                    {
1740                                        let scrollbars = Scrollbars::new(ScrollAxes::Horizontal)
1741                                            .id(("markdown-code-block-scrollbar", range.start))
1742                                            .tracked_scroll_handle(scroll_handle)
1743                                            .with_track_along(
1744                                                ScrollAxes::Horizontal,
1745                                                cx.theme().colors().editor_background,
1746                                            )
1747                                            .notify_content();
1748
1749                                        parent_container
1750                                            .rounded_lg()
1751                                            .custom_scrollbars(scrollbars, window, cx)
1752                                            .into()
1753                                    } else {
1754                                        parent_container.into()
1755                                    };
1756
1757                                    if let CodeBlockRenderer::Default { border: true, .. } =
1758                                        &self.code_block_renderer
1759                                    {
1760                                        parent_container = parent_container
1761                                            .rounded_md()
1762                                            .border_1()
1763                                            .border_color(cx.theme().colors().border_variant);
1764                                    }
1765
1766                                    parent_container.style().refine(&self.style.code_block);
1767                                    builder.push_div(parent_container, range, markdown_end);
1768
1769                                    let code_block = div()
1770                                        .id(("code-block", range.start))
1771                                        .rounded_lg()
1772                                        .map(|mut code_block| {
1773                                            if let Some(scroll_handle) = scroll_handle.as_ref() {
1774                                                code_block.style().restrict_scroll_to_axis =
1775                                                    Some(true);
1776                                                code_block
1777                                                    .flex()
1778                                                    .overflow_x_scroll()
1779                                                    .track_scroll(scroll_handle)
1780                                            } else {
1781                                                code_block.w_full()
1782                                            }
1783                                        });
1784
1785                                    builder.push_text_style(self.style.code_block.text.to_owned());
1786                                    builder.push_code_block(language);
1787                                    builder.push_div(code_block, range, markdown_end);
1788                                }
1789                                (CodeBlockRenderer::Custom { .. }, _) => {}
1790                            }
1791                        }
1792                        MarkdownTag::HtmlBlock => {
1793                            builder.push_div(div(), range, markdown_end);
1794                            if let Some(block) = parsed_markdown.html_blocks.get(&range.start) {
1795                                self.render_html_block(block, &mut builder, markdown_end, cx);
1796                                handled_html_block = true;
1797                            }
1798                        }
1799                        MarkdownTag::List(bullet_index) => {
1800                            builder.push_list(*bullet_index);
1801                            builder.push_div(div().pl_2p5(), range, markdown_end);
1802                        }
1803                        MarkdownTag::Item => {
1804                            let bullet =
1805                                if let Some((task_range, MarkdownEvent::TaskListMarker(checked))) =
1806                                    parsed_markdown.events.get(index.saturating_add(1))
1807                                {
1808                                    let source = &parsed_markdown.source()[range.clone()];
1809                                    let checked = *checked;
1810                                    let toggle_state = if checked {
1811                                        ToggleState::Selected
1812                                    } else {
1813                                        ToggleState::Unselected
1814                                    };
1815
1816                                    let checkbox = Checkbox::new(
1817                                        ElementId::Name(source.to_string().into()),
1818                                        toggle_state,
1819                                    )
1820                                    .fill();
1821
1822                                    if let Some(on_toggle) = self.on_checkbox_toggle.clone() {
1823                                        let task_source_range = task_range.clone();
1824                                        checkbox
1825                                            .on_click(move |_state, window, cx| {
1826                                                on_toggle(
1827                                                    task_source_range.clone(),
1828                                                    !checked,
1829                                                    window,
1830                                                    cx,
1831                                                );
1832                                            })
1833                                            .into_any_element()
1834                                    } else {
1835                                        checkbox.visualization_only(true).into_any_element()
1836                                    }
1837                                } else if let Some(bullet_index) = builder.next_bullet_index() {
1838                                    div().child(format!("{}.", bullet_index)).into_any_element()
1839                                } else {
1840                                    div().child("").into_any_element()
1841                                };
1842                            self.push_markdown_list_item(&mut builder, bullet, range, markdown_end);
1843                        }
1844                        MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
1845                            font_style: Some(FontStyle::Italic),
1846                            ..Default::default()
1847                        }),
1848                        MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
1849                            font_weight: Some(FontWeight::BOLD),
1850                            ..Default::default()
1851                        }),
1852                        MarkdownTag::Strikethrough => {
1853                            builder.push_text_style(TextStyleRefinement {
1854                                strikethrough: Some(StrikethroughStyle {
1855                                    thickness: px(1.),
1856                                    color: None,
1857                                }),
1858                                ..Default::default()
1859                            })
1860                        }
1861                        MarkdownTag::Link { dest_url, .. } => {
1862                            if builder.code_block_stack.is_empty() {
1863                                builder.push_link(dest_url.clone(), range.clone());
1864                                let style = self
1865                                    .style
1866                                    .link_callback
1867                                    .as_ref()
1868                                    .and_then(|callback| callback(dest_url, cx))
1869                                    .unwrap_or_else(|| self.style.link.clone());
1870                                builder.push_text_style(style)
1871                            }
1872                        }
1873                        MarkdownTag::FootnoteDefinition(label) => {
1874                            if !builder.rendered_footnote_separator {
1875                                builder.rendered_footnote_separator = true;
1876                                builder.push_div(
1877                                    div()
1878                                        .border_t_1()
1879                                        .mt_2()
1880                                        .border_color(self.style.rule_color),
1881                                    range,
1882                                    markdown_end,
1883                                );
1884                                builder.pop_div();
1885                            }
1886                            builder.push_div(
1887                                div()
1888                                    .pt_1()
1889                                    .mb_1()
1890                                    .line_height(rems(1.3))
1891                                    .text_size(rems(0.85))
1892                                    .h_flex()
1893                                    .items_start()
1894                                    .gap_2()
1895                                    .child(
1896                                        div().text_size(rems(0.85)).child(format!("{}.", label)),
1897                                    ),
1898                                range,
1899                                markdown_end,
1900                            );
1901                            builder.push_div(div().flex_1().w_0(), range, markdown_end);
1902                        }
1903                        MarkdownTag::MetadataBlock(_) => {}
1904                        MarkdownTag::Table(alignments) => {
1905                            builder.table.start(alignments.clone());
1906
1907                            let column_count = alignments.len();
1908                            builder.push_div(
1909                                div()
1910                                    .id(("table", range.start))
1911                                    .grid()
1912                                    .grid_cols(column_count as u16)
1913                                    .when(self.style.table_columns_min_size, |this| {
1914                                        this.grid_cols_min_content(column_count as u16)
1915                                    })
1916                                    .when(!self.style.table_columns_min_size, |this| {
1917                                        this.grid_cols(column_count as u16)
1918                                    })
1919                                    .w_full()
1920                                    .mb_2()
1921                                    .border(px(1.5))
1922                                    .border_color(cx.theme().colors().border)
1923                                    .rounded_sm()
1924                                    .overflow_hidden(),
1925                                range,
1926                                markdown_end,
1927                            );
1928                        }
1929                        MarkdownTag::TableHead => {
1930                            builder.table.start_head();
1931                            builder.push_text_style(TextStyleRefinement {
1932                                font_weight: Some(FontWeight::SEMIBOLD),
1933                                ..Default::default()
1934                            });
1935                        }
1936                        MarkdownTag::TableRow => {
1937                            builder.table.start_row();
1938                        }
1939                        MarkdownTag::TableCell => {
1940                            let is_header = builder.table.in_head;
1941                            let row_index = builder.table.row_index;
1942                            let col_index = builder.table.col_index;
1943
1944                            builder.push_div(
1945                                div()
1946                                    .when(col_index > 0, |this| this.border_l_1())
1947                                    .when(row_index > 0, |this| this.border_t_1())
1948                                    .border_color(cx.theme().colors().border)
1949                                    .px_1()
1950                                    .py_0p5()
1951                                    .when(is_header, |this| {
1952                                        this.bg(cx.theme().colors().title_bar_background)
1953                                    })
1954                                    .when(!is_header && row_index % 2 == 1, |this| {
1955                                        this.bg(cx.theme().colors().panel_background)
1956                                    }),
1957                                range,
1958                                markdown_end,
1959                            );
1960                        }
1961                        _ => log::debug!("unsupported markdown tag {:?}", tag),
1962                    }
1963                }
1964                MarkdownEvent::End(tag) => match tag {
1965                    MarkdownTagEnd::Image => {
1966                        current_img_block_range.take();
1967                    }
1968                    MarkdownTagEnd::Paragraph => {
1969                        self.pop_markdown_paragraph(&mut builder);
1970                    }
1971                    MarkdownTagEnd::Heading(_) => {
1972                        self.pop_markdown_heading(&mut builder);
1973                    }
1974                    MarkdownTagEnd::BlockQuote(_kind) => {
1975                        self.pop_markdown_block_quote(&mut builder);
1976                    }
1977                    MarkdownTagEnd::CodeBlock => {
1978                        builder.trim_trailing_newline();
1979
1980                        builder.pop_div();
1981                        builder.pop_code_block();
1982                        builder.pop_text_style();
1983
1984                        if let CodeBlockRenderer::Default {
1985                            copy_button_visibility,
1986                            ..
1987                        } = &self.code_block_renderer
1988                            && *copy_button_visibility != CopyButtonVisibility::Hidden
1989                        {
1990                            builder.modify_current_div(|el| {
1991                                let content_range = parser::extract_code_block_content_range(
1992                                    &parsed_markdown.source()[range.clone()],
1993                                );
1994                                let content_range = content_range.start + range.start
1995                                    ..content_range.end + range.start;
1996
1997                                let code = parsed_markdown.source()[content_range].to_string();
1998                                let codeblock = render_copy_code_block_button(
1999                                    range.end,
2000                                    code,
2001                                    self.markdown.clone(),
2002                                );
2003                                el.child(
2004                                    h_flex()
2005                                        .w_4()
2006                                        .absolute()
2007                                        .justify_end()
2008                                        .when_else(
2009                                            *copy_button_visibility
2010                                                == CopyButtonVisibility::VisibleOnHover,
2011                                            |this| {
2012                                                this.top_0()
2013                                                    .right_0()
2014                                                    .visible_on_hover("code_block")
2015                                            },
2016                                            |this| this.top_1p5().right_1p5(),
2017                                        )
2018                                        .child(codeblock),
2019                                )
2020                            });
2021                        }
2022
2023                        // Pop the parent container.
2024                        builder.pop_div();
2025                    }
2026                    MarkdownTagEnd::HtmlBlock => builder.pop_div(),
2027                    MarkdownTagEnd::List(_) => {
2028                        builder.pop_list();
2029                        builder.pop_div();
2030                    }
2031                    MarkdownTagEnd::Item => {
2032                        self.pop_markdown_list_item(&mut builder);
2033                    }
2034                    MarkdownTagEnd::Emphasis => builder.pop_text_style(),
2035                    MarkdownTagEnd::Strong => builder.pop_text_style(),
2036                    MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
2037                    MarkdownTagEnd::Link => {
2038                        if builder.code_block_stack.is_empty() {
2039                            builder.pop_text_style()
2040                        }
2041                    }
2042                    MarkdownTagEnd::Table => {
2043                        builder.pop_div();
2044                        builder.table.end();
2045                    }
2046                    MarkdownTagEnd::TableHead => {
2047                        builder.pop_text_style();
2048                        builder.table.end_head();
2049                    }
2050                    MarkdownTagEnd::TableRow => {
2051                        builder.table.end_row();
2052                    }
2053                    MarkdownTagEnd::TableCell => {
2054                        builder.replace_pending_checkbox(range);
2055                        builder.pop_div();
2056                        builder.table.end_cell();
2057                    }
2058                    MarkdownTagEnd::FootnoteDefinition => {
2059                        builder.pop_div();
2060                        builder.pop_div();
2061                    }
2062                    _ => log::debug!("unsupported markdown tag end: {:?}", tag),
2063                },
2064                MarkdownEvent::Text => {
2065                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2066                }
2067                MarkdownEvent::SubstitutedText(text) => {
2068                    builder.push_text(text, range.clone());
2069                }
2070                MarkdownEvent::Code => {
2071                    builder.push_text_style(self.style.inline_code.clone());
2072                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2073                    builder.pop_text_style();
2074                }
2075                MarkdownEvent::Html => {
2076                    let html = &parsed_markdown.source[range.clone()];
2077                    if html.starts_with("<!--") {
2078                        builder.html_comment = true;
2079                    }
2080                    if html.trim_end().ends_with("-->") {
2081                        builder.html_comment = false;
2082                        continue;
2083                    }
2084                    if builder.html_comment {
2085                        continue;
2086                    }
2087                    builder.push_text(html, range.clone());
2088                }
2089                MarkdownEvent::InlineHtml => {
2090                    let html = &parsed_markdown.source[range.clone()];
2091                    if html.starts_with("<code>") {
2092                        builder.push_text_style(self.style.inline_code.clone());
2093                        continue;
2094                    }
2095                    if html.trim_end().starts_with("</code>") {
2096                        builder.pop_text_style();
2097                        continue;
2098                    }
2099                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2100                }
2101                MarkdownEvent::Rule => {
2102                    builder.push_div(
2103                        div()
2104                            .border_b_1()
2105                            .my_2()
2106                            .border_color(self.style.rule_color),
2107                        range,
2108                        markdown_end,
2109                    );
2110                    builder.pop_div()
2111                }
2112                MarkdownEvent::SoftBreak => builder.push_text(" ", range.clone()),
2113                MarkdownEvent::HardBreak => builder.push_text("\n", range.clone()),
2114                MarkdownEvent::TaskListMarker(_) => {
2115                    // handled inside the `MarkdownTag::Item` case
2116                }
2117                MarkdownEvent::FootnoteReference(label) => {
2118                    builder.push_footnote_ref(label.clone(), range.clone());
2119                    builder.push_text_style(self.style.link.clone());
2120                    builder.push_text(&format!("[{label}]"), range.clone());
2121                    builder.pop_text_style();
2122                }
2123            }
2124        }
2125        if self.style.code_block_overflow_x_scroll {
2126            let code_block_ids = code_block_ids;
2127            self.markdown.update(cx, move |markdown, _| {
2128                markdown.retain_code_block_scroll_handles(&code_block_ids);
2129            });
2130        } else {
2131            self.markdown
2132                .update(cx, |markdown, _| markdown.clear_code_block_scroll_handles());
2133        }
2134        let mut rendered_markdown = builder.build();
2135        let child_layout_id = rendered_markdown.element.request_layout(window, cx);
2136        let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
2137        (layout_id, rendered_markdown)
2138    }
2139
2140    fn prepaint(
2141        &mut self,
2142        _id: Option<&GlobalElementId>,
2143        _inspector_id: Option<&gpui::InspectorElementId>,
2144        bounds: Bounds<Pixels>,
2145        rendered_markdown: &mut Self::RequestLayoutState,
2146        window: &mut Window,
2147        cx: &mut App,
2148    ) -> Self::PrepaintState {
2149        let focus_handle = self.markdown.read(cx).focus_handle.clone();
2150        window.set_focus_handle(&focus_handle, cx);
2151        window.set_view_id(self.markdown.entity_id());
2152
2153        let hitbox = window.insert_hitbox(bounds, HitboxBehavior::Normal);
2154        rendered_markdown.element.prepaint(window, cx);
2155        self.autoscroll(&rendered_markdown.text, window, cx);
2156        hitbox
2157    }
2158
2159    fn paint(
2160        &mut self,
2161        _id: Option<&GlobalElementId>,
2162        _inspector_id: Option<&gpui::InspectorElementId>,
2163        bounds: Bounds<Pixels>,
2164        rendered_markdown: &mut Self::RequestLayoutState,
2165        hitbox: &mut Self::PrepaintState,
2166        window: &mut Window,
2167        cx: &mut App,
2168    ) {
2169        let mut context = KeyContext::default();
2170        context.add("Markdown");
2171        window.set_key_context(context);
2172        window.on_action(std::any::TypeId::of::<crate::Copy>(), {
2173            let entity = self.markdown.clone();
2174            let text = rendered_markdown.text.clone();
2175            move |_, phase, window, cx| {
2176                let text = text.clone();
2177                if phase == DispatchPhase::Bubble {
2178                    entity.update(cx, move |this, cx| this.copy(&text, window, cx))
2179                }
2180            }
2181        });
2182        window.on_action(std::any::TypeId::of::<crate::CopyAsMarkdown>(), {
2183            let entity = self.markdown.clone();
2184            move |_, phase, window, cx| {
2185                if phase == DispatchPhase::Bubble {
2186                    entity.update(cx, move |this, cx| this.copy_as_markdown(window, cx))
2187                }
2188            }
2189        });
2190
2191        self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
2192        rendered_markdown.element.paint(window, cx);
2193        self.paint_search_highlights(bounds, &rendered_markdown.text, window, cx);
2194        self.paint_selection(bounds, &rendered_markdown.text, window, cx);
2195    }
2196}
2197
2198fn apply_heading_style(
2199    mut heading: Div,
2200    level: pulldown_cmark::HeadingLevel,
2201    custom_styles: Option<&HeadingLevelStyles>,
2202) -> Div {
2203    heading = match level {
2204        pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
2205        pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
2206        pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
2207        pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
2208        pulldown_cmark::HeadingLevel::H5 => heading.text_base(),
2209        pulldown_cmark::HeadingLevel::H6 => heading.text_sm(),
2210    };
2211
2212    if let Some(styles) = custom_styles {
2213        let style_opt = match level {
2214            pulldown_cmark::HeadingLevel::H1 => &styles.h1,
2215            pulldown_cmark::HeadingLevel::H2 => &styles.h2,
2216            pulldown_cmark::HeadingLevel::H3 => &styles.h3,
2217            pulldown_cmark::HeadingLevel::H4 => &styles.h4,
2218            pulldown_cmark::HeadingLevel::H5 => &styles.h5,
2219            pulldown_cmark::HeadingLevel::H6 => &styles.h6,
2220        };
2221
2222        if let Some(style) = style_opt {
2223            heading.style().text = style.clone();
2224        }
2225    }
2226
2227    heading
2228}
2229
2230fn render_copy_code_block_button(
2231    id: usize,
2232    code: String,
2233    markdown: Entity<Markdown>,
2234) -> impl IntoElement {
2235    let id = ElementId::named_usize("copy-markdown-code", id);
2236
2237    CopyButton::new(id.clone(), code.clone()).custom_on_click({
2238        let markdown = markdown;
2239        move |_window, cx| {
2240            let id = id.clone();
2241            markdown.update(cx, |this, cx| {
2242                this.copied_code_blocks.insert(id.clone());
2243
2244                cx.write_to_clipboard(ClipboardItem::new_string(code.clone()));
2245
2246                cx.spawn(async move |this, cx| {
2247                    cx.background_executor().timer(Duration::from_secs(2)).await;
2248
2249                    cx.update(|cx| {
2250                        this.update(cx, |this, cx| {
2251                            this.copied_code_blocks.remove(&id);
2252                            cx.notify();
2253                        })
2254                    })
2255                    .ok();
2256                })
2257                .detach();
2258            });
2259        }
2260    })
2261}
2262
2263impl IntoElement for MarkdownElement {
2264    type Element = Self;
2265
2266    fn into_element(self) -> Self::Element {
2267        self
2268    }
2269}
2270
2271pub enum AnyDiv {
2272    Div(Div),
2273    Stateful(Stateful<Div>),
2274}
2275
2276impl AnyDiv {
2277    fn into_any_element(self) -> AnyElement {
2278        match self {
2279            Self::Div(div) => div.into_any_element(),
2280            Self::Stateful(div) => div.into_any_element(),
2281        }
2282    }
2283}
2284
2285impl From<Div> for AnyDiv {
2286    fn from(value: Div) -> Self {
2287        Self::Div(value)
2288    }
2289}
2290
2291impl From<Stateful<Div>> for AnyDiv {
2292    fn from(value: Stateful<Div>) -> Self {
2293        Self::Stateful(value)
2294    }
2295}
2296
2297impl Styled for AnyDiv {
2298    fn style(&mut self) -> &mut StyleRefinement {
2299        match self {
2300            Self::Div(div) => div.style(),
2301            Self::Stateful(div) => div.style(),
2302        }
2303    }
2304}
2305
2306impl ParentElement for AnyDiv {
2307    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2308        match self {
2309            Self::Div(div) => div.extend(elements),
2310            Self::Stateful(div) => div.extend(elements),
2311        }
2312    }
2313}
2314
2315#[derive(Default)]
2316struct TableState {
2317    alignments: Vec<Alignment>,
2318    in_head: bool,
2319    row_index: usize,
2320    col_index: usize,
2321}
2322
2323impl TableState {
2324    fn start(&mut self, alignments: Vec<Alignment>) {
2325        self.alignments = alignments;
2326        self.in_head = false;
2327        self.row_index = 0;
2328        self.col_index = 0;
2329    }
2330
2331    fn end(&mut self) {
2332        self.alignments.clear();
2333        self.in_head = false;
2334        self.row_index = 0;
2335        self.col_index = 0;
2336    }
2337
2338    fn start_head(&mut self) {
2339        self.in_head = true;
2340    }
2341
2342    fn end_head(&mut self) {
2343        self.in_head = false;
2344    }
2345
2346    fn start_row(&mut self) {
2347        self.col_index = 0;
2348    }
2349
2350    fn end_row(&mut self) {
2351        self.row_index += 1;
2352    }
2353
2354    fn end_cell(&mut self) {
2355        self.col_index += 1;
2356    }
2357}
2358
2359struct MarkdownElementBuilder {
2360    div_stack: Vec<AnyDiv>,
2361    rendered_lines: Vec<RenderedLine>,
2362    pending_line: PendingLine,
2363    rendered_links: Vec<RenderedLink>,
2364    rendered_footnote_refs: Vec<RenderedFootnoteRef>,
2365    current_source_index: usize,
2366    html_comment: bool,
2367    rendered_footnote_separator: bool,
2368    base_text_style: TextStyle,
2369    text_style_stack: Vec<TextStyleRefinement>,
2370    code_block_stack: Vec<Option<Arc<Language>>>,
2371    list_stack: Vec<ListStackEntry>,
2372    table: TableState,
2373    syntax_theme: Arc<SyntaxTheme>,
2374}
2375
2376#[derive(Default)]
2377struct PendingLine {
2378    text: String,
2379    runs: Vec<TextRun>,
2380    source_mappings: Vec<SourceMapping>,
2381}
2382
2383struct ListStackEntry {
2384    bullet_index: Option<u64>,
2385}
2386
2387impl MarkdownElementBuilder {
2388    fn new(
2389        container_style: &StyleRefinement,
2390        base_text_style: TextStyle,
2391        syntax_theme: Arc<SyntaxTheme>,
2392    ) -> Self {
2393        Self {
2394            div_stack: vec![{
2395                let mut base_div = div();
2396                base_div.style().refine(container_style);
2397                base_div.debug_selector(|| "inner".into()).into()
2398            }],
2399            rendered_lines: Vec::new(),
2400            pending_line: PendingLine::default(),
2401            rendered_links: Vec::new(),
2402            rendered_footnote_refs: Vec::new(),
2403            current_source_index: 0,
2404            html_comment: false,
2405            rendered_footnote_separator: false,
2406            base_text_style,
2407            text_style_stack: Vec::new(),
2408            code_block_stack: Vec::new(),
2409            list_stack: Vec::new(),
2410            table: TableState::default(),
2411            syntax_theme,
2412        }
2413    }
2414
2415    fn push_text_style(&mut self, style: TextStyleRefinement) {
2416        self.text_style_stack.push(style);
2417    }
2418
2419    fn text_style(&self) -> TextStyle {
2420        let mut style = self.base_text_style.clone();
2421        for refinement in &self.text_style_stack {
2422            style.refine(refinement);
2423        }
2424        style
2425    }
2426
2427    fn pop_text_style(&mut self) {
2428        self.text_style_stack.pop();
2429    }
2430
2431    fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
2432        let mut div = div.into();
2433        self.flush_text();
2434
2435        if range.start == 0 {
2436            // Remove the top margin on the first element.
2437            div.style().refine(&StyleRefinement {
2438                margin: gpui::EdgesRefinement {
2439                    top: Some(Length::Definite(px(0.).into())),
2440                    left: None,
2441                    right: None,
2442                    bottom: None,
2443                },
2444                ..Default::default()
2445            });
2446        }
2447
2448        if range.end == markdown_end {
2449            div.style().refine(&StyleRefinement {
2450                margin: gpui::EdgesRefinement {
2451                    top: None,
2452                    left: None,
2453                    right: None,
2454                    bottom: Some(Length::Definite(rems(0.).into())),
2455                },
2456                ..Default::default()
2457            });
2458        }
2459
2460        self.div_stack.push(div);
2461    }
2462
2463    fn push_root_block(&mut self, range: &Range<usize>, markdown_end: usize) {
2464        self.push_div(
2465            div().group("markdown-root-block").relative(),
2466            range,
2467            markdown_end,
2468        );
2469        self.push_div(div().pl_4(), range, markdown_end);
2470    }
2471
2472    fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
2473        self.flush_text();
2474        if let Some(div) = self.div_stack.pop() {
2475            self.div_stack.push(f(div));
2476        }
2477    }
2478
2479    fn pop_root_block(
2480        &mut self,
2481        is_active: bool,
2482        active_gutter_color: Hsla,
2483        hovered_gutter_color: Hsla,
2484    ) {
2485        self.pop_div();
2486        self.modify_current_div(|el| {
2487            el.child(
2488                div()
2489                    .h_full()
2490                    .w(px(4.0))
2491                    .when(is_active, |this| this.bg(active_gutter_color))
2492                    .group_hover("markdown-root-block", |this| {
2493                        if is_active {
2494                            this
2495                        } else {
2496                            this.bg(hovered_gutter_color)
2497                        }
2498                    })
2499                    .rounded_xs()
2500                    .absolute()
2501                    .left_0()
2502                    .top_0(),
2503            )
2504        });
2505        self.pop_div();
2506    }
2507
2508    fn pop_div(&mut self) {
2509        self.flush_text();
2510        let div = self.div_stack.pop().unwrap().into_any_element();
2511        self.div_stack.last_mut().unwrap().extend(iter::once(div));
2512    }
2513
2514    fn push_sourced_element(&mut self, source_range: Range<usize>, element: impl Into<AnyElement>) {
2515        self.flush_text();
2516        let anchor = self.render_source_anchor(source_range);
2517        self.div_stack.last_mut().unwrap().extend([{
2518            div()
2519                .relative()
2520                .child(anchor)
2521                .child(element.into())
2522                .into_any_element()
2523        }]);
2524    }
2525
2526    fn push_list(&mut self, bullet_index: Option<u64>) {
2527        self.list_stack.push(ListStackEntry { bullet_index });
2528    }
2529
2530    fn next_bullet_index(&mut self) -> Option<u64> {
2531        self.list_stack.last_mut().and_then(|entry| {
2532            let item_index = entry.bullet_index.as_mut()?;
2533            *item_index += 1;
2534            Some(*item_index - 1)
2535        })
2536    }
2537
2538    fn pop_list(&mut self) {
2539        self.list_stack.pop();
2540    }
2541
2542    fn push_code_block(&mut self, language: Option<Arc<Language>>) {
2543        self.code_block_stack.push(language);
2544    }
2545
2546    fn pop_code_block(&mut self) {
2547        self.code_block_stack.pop();
2548    }
2549
2550    fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
2551        self.rendered_links.push(RenderedLink {
2552            source_range,
2553            destination_url,
2554        });
2555    }
2556
2557    fn push_footnote_ref(&mut self, label: SharedString, source_range: Range<usize>) {
2558        self.rendered_footnote_refs.push(RenderedFootnoteRef {
2559            source_range,
2560            label,
2561        });
2562    }
2563
2564    fn push_text(&mut self, text: &str, source_range: Range<usize>) {
2565        self.pending_line.source_mappings.push(SourceMapping {
2566            rendered_index: self.pending_line.text.len(),
2567            source_index: source_range.start,
2568        });
2569        self.pending_line.text.push_str(text);
2570        self.current_source_index = source_range.end;
2571
2572        if let Some(Some(language)) = self.code_block_stack.last() {
2573            let mut offset = 0;
2574            for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
2575                if range.start > offset {
2576                    self.pending_line
2577                        .runs
2578                        .push(self.text_style().to_run(range.start - offset));
2579                }
2580
2581                let mut run_style = self.text_style();
2582                if let Some(highlight) = self.syntax_theme.get(highlight_id).cloned() {
2583                    run_style = run_style.highlight(highlight);
2584                }
2585
2586                self.pending_line.runs.push(run_style.to_run(range.len()));
2587                offset = range.end;
2588            }
2589
2590            if offset < text.len() {
2591                self.pending_line
2592                    .runs
2593                    .push(self.text_style().to_run(text.len() - offset));
2594            }
2595        } else {
2596            self.pending_line
2597                .runs
2598                .push(self.text_style().to_run(text.len()));
2599        }
2600    }
2601
2602    fn trim_trailing_newline(&mut self) {
2603        if self.pending_line.text.ends_with('\n') {
2604            self.pending_line
2605                .text
2606                .truncate(self.pending_line.text.len() - 1);
2607            self.pending_line.runs.last_mut().unwrap().len -= 1;
2608            self.current_source_index -= 1;
2609        }
2610    }
2611
2612    fn replace_pending_checkbox(&mut self, source_range: &Range<usize>) {
2613        let trimmed = self.pending_line.text.trim();
2614        if trimmed == "[x]" || trimmed == "[X]" || trimmed == "[ ]" {
2615            let checked = trimmed != "[ ]";
2616            self.pending_line = PendingLine::default();
2617            let checkbox = Checkbox::new(
2618                ElementId::Name(
2619                    format!("table_checkbox_{}_{}", source_range.start, source_range.end).into(),
2620                ),
2621                if checked {
2622                    ToggleState::Selected
2623                } else {
2624                    ToggleState::Unselected
2625                },
2626            )
2627            .fill()
2628            .visualization_only(true)
2629            .into_any_element();
2630            self.div_stack.last_mut().unwrap().extend([checkbox]);
2631        }
2632    }
2633
2634    fn render_source_anchor(&mut self, source_range: Range<usize>) -> AnyElement {
2635        let mut text_style = self.base_text_style.clone();
2636        text_style.color = Hsla::transparent_black();
2637        let text = "\u{200B}";
2638        let styled_text = StyledText::new(text).with_runs(vec![text_style.to_run(text.len())]);
2639        self.rendered_lines.push(RenderedLine {
2640            layout: styled_text.layout().clone(),
2641            source_mappings: vec![SourceMapping {
2642                rendered_index: 0,
2643                source_index: source_range.start,
2644            }],
2645            source_end: source_range.end,
2646            language: None,
2647        });
2648        div()
2649            .absolute()
2650            .top_0()
2651            .left_0()
2652            .opacity(0.)
2653            .child(styled_text)
2654            .into_any_element()
2655    }
2656
2657    fn flush_text(&mut self) {
2658        let line = mem::take(&mut self.pending_line);
2659        if line.text.is_empty() {
2660            return;
2661        }
2662
2663        let text = StyledText::new(line.text).with_runs(line.runs);
2664        self.rendered_lines.push(RenderedLine {
2665            layout: text.layout().clone(),
2666            source_mappings: line.source_mappings,
2667            source_end: self.current_source_index,
2668            language: self.code_block_stack.last().cloned().flatten(),
2669        });
2670        self.div_stack.last_mut().unwrap().extend([text.into_any()]);
2671    }
2672
2673    fn build(mut self) -> RenderedMarkdown {
2674        debug_assert_eq!(self.div_stack.len(), 1);
2675        self.flush_text();
2676        RenderedMarkdown {
2677            element: self.div_stack.pop().unwrap().into_any_element(),
2678            text: RenderedText {
2679                lines: self.rendered_lines.into(),
2680                links: self.rendered_links.into(),
2681                footnote_refs: self.rendered_footnote_refs.into(),
2682            },
2683        }
2684    }
2685}
2686
2687struct RenderedLine {
2688    layout: TextLayout,
2689    source_mappings: Vec<SourceMapping>,
2690    source_end: usize,
2691    language: Option<Arc<Language>>,
2692}
2693
2694impl RenderedLine {
2695    fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
2696        if source_index >= self.source_end {
2697            return self.layout.len();
2698        }
2699
2700        let mapping = match self
2701            .source_mappings
2702            .binary_search_by_key(&source_index, |probe| probe.source_index)
2703        {
2704            Ok(ix) => &self.source_mappings[ix],
2705            Err(ix) => &self.source_mappings[ix - 1],
2706        };
2707        (mapping.rendered_index + (source_index - mapping.source_index)).min(self.layout.len())
2708    }
2709
2710    fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
2711        if rendered_index >= self.layout.len() {
2712            return self.source_end;
2713        }
2714
2715        let mapping = match self
2716            .source_mappings
2717            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
2718        {
2719            Ok(ix) => &self.source_mappings[ix],
2720            Err(ix) => &self.source_mappings[ix - 1],
2721        };
2722        mapping.source_index + (rendered_index - mapping.rendered_index)
2723    }
2724
2725    /// Returns the source index for use as an exclusive range end at a word/selection boundary.
2726    /// When the rendered index is exactly at the start of a segment with a gap from the previous
2727    /// segment (e.g., after stripped markdown syntax like backticks), this returns the end of the
2728    /// previous segment rather than the start of the current one.
2729    fn source_index_for_exclusive_rendered_end(&self, rendered_index: usize) -> usize {
2730        if rendered_index >= self.layout.len() {
2731            return self.source_end;
2732        }
2733
2734        let ix = match self
2735            .source_mappings
2736            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
2737        {
2738            Ok(ix) => ix,
2739            Err(ix) => {
2740                return self.source_mappings[ix - 1].source_index
2741                    + (rendered_index - self.source_mappings[ix - 1].rendered_index);
2742            }
2743        };
2744
2745        // Exact match at the start of a segment. Check if there's a gap from the previous segment.
2746        if ix > 0 {
2747            let prev_mapping = &self.source_mappings[ix - 1];
2748            let mapping = &self.source_mappings[ix];
2749            let prev_segment_len = mapping.rendered_index - prev_mapping.rendered_index;
2750            let prev_source_end = prev_mapping.source_index + prev_segment_len;
2751            if prev_source_end < mapping.source_index {
2752                return prev_source_end;
2753            }
2754        }
2755
2756        self.source_mappings[ix].source_index
2757    }
2758
2759    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2760        let line_rendered_index;
2761        let out_of_bounds;
2762        match self.layout.index_for_position(position) {
2763            Ok(ix) => {
2764                line_rendered_index = ix;
2765                out_of_bounds = false;
2766            }
2767            Err(ix) => {
2768                line_rendered_index = ix;
2769                out_of_bounds = true;
2770            }
2771        };
2772        let source_index = self.source_index_for_rendered_index(line_rendered_index);
2773        if out_of_bounds {
2774            Err(source_index)
2775        } else {
2776            Ok(source_index)
2777        }
2778    }
2779}
2780
2781#[derive(Copy, Clone, Debug, Default)]
2782struct SourceMapping {
2783    rendered_index: usize,
2784    source_index: usize,
2785}
2786
2787pub struct RenderedMarkdown {
2788    element: AnyElement,
2789    text: RenderedText,
2790}
2791
2792#[derive(Clone)]
2793struct RenderedText {
2794    lines: Rc<[RenderedLine]>,
2795    links: Rc<[RenderedLink]>,
2796    footnote_refs: Rc<[RenderedFootnoteRef]>,
2797}
2798
2799#[derive(Debug, Clone, Eq, PartialEq)]
2800struct RenderedLink {
2801    source_range: Range<usize>,
2802    destination_url: SharedString,
2803}
2804
2805#[derive(Debug, Clone, Eq, PartialEq)]
2806struct RenderedFootnoteRef {
2807    source_range: Range<usize>,
2808    label: SharedString,
2809}
2810
2811impl RenderedText {
2812    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2813        let mut lines = self.lines.iter().peekable();
2814        let mut fallback_line: Option<&RenderedLine> = None;
2815
2816        while let Some(line) = lines.next() {
2817            let line_bounds = line.layout.bounds();
2818
2819            // Exact match: position is within bounds (handles overlapping bounds like table columns)
2820            if line_bounds.contains(&position) {
2821                return line.source_index_for_position(position);
2822            }
2823
2824            // Track fallback for Y-coordinate based matching
2825            if position.y <= line_bounds.bottom() && fallback_line.is_none() {
2826                fallback_line = Some(line);
2827            }
2828
2829            // Handle gap between lines
2830            if position.y > line_bounds.bottom() {
2831                if let Some(next_line) = lines.peek()
2832                    && position.y < next_line.layout.bounds().top()
2833                {
2834                    return Err(line.source_end);
2835                }
2836            }
2837        }
2838
2839        // Fall back to Y-coordinate matched line
2840        if let Some(line) = fallback_line {
2841            return line.source_index_for_position(position);
2842        }
2843
2844        Err(self.lines.last().map_or(0, |line| line.source_end))
2845    }
2846
2847    fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
2848        for line in self.lines.iter() {
2849            let line_source_start = line.source_mappings.first().unwrap().source_index;
2850            if source_index < line_source_start {
2851                break;
2852            } else if source_index > line.source_end {
2853                continue;
2854            } else {
2855                let line_height = line.layout.line_height();
2856                let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
2857                let position = line.layout.position_for_index(rendered_index_within_line)?;
2858                return Some((position, line_height));
2859            }
2860        }
2861        None
2862    }
2863
2864    fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
2865        for line in self.lines.iter() {
2866            if source_index > line.source_end {
2867                continue;
2868            }
2869
2870            let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
2871            let rendered_index_in_line =
2872                line.rendered_index_for_source_index(source_index) - line_rendered_start;
2873            let text = line.layout.text();
2874
2875            let scope = line.language.as_ref().map(|l| l.default_scope());
2876            let classifier = CharClassifier::new(scope);
2877
2878            let mut prev_chars = text[..rendered_index_in_line].chars().rev().peekable();
2879            let mut next_chars = text[rendered_index_in_line..].chars().peekable();
2880
2881            let word_kind = std::cmp::max(
2882                prev_chars.peek().map(|&c| classifier.kind(c)),
2883                next_chars.peek().map(|&c| classifier.kind(c)),
2884            );
2885
2886            let mut start = rendered_index_in_line;
2887            for c in prev_chars {
2888                if Some(classifier.kind(c)) == word_kind {
2889                    start -= c.len_utf8();
2890                } else {
2891                    break;
2892                }
2893            }
2894
2895            let mut end = rendered_index_in_line;
2896            for c in next_chars {
2897                if Some(classifier.kind(c)) == word_kind {
2898                    end += c.len_utf8();
2899                } else {
2900                    break;
2901                }
2902            }
2903
2904            return line.source_index_for_rendered_index(line_rendered_start + start)
2905                ..line.source_index_for_exclusive_rendered_end(line_rendered_start + end);
2906        }
2907
2908        source_index..source_index
2909    }
2910
2911    fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
2912        for line in self.lines.iter() {
2913            if source_index > line.source_end {
2914                continue;
2915            }
2916            let line_source_start = line.source_mappings.first().unwrap().source_index;
2917            return line_source_start..line.source_end;
2918        }
2919
2920        source_index..source_index
2921    }
2922
2923    fn text_for_range(&self, range: Range<usize>) -> String {
2924        let mut accumulator = String::new();
2925
2926        for line in self.lines.iter() {
2927            if range.start > line.source_end {
2928                continue;
2929            }
2930            let line_source_start = line.source_mappings.first().unwrap().source_index;
2931            if range.end < line_source_start {
2932                break;
2933            }
2934
2935            let text = line.layout.text();
2936
2937            let start = if range.start < line_source_start {
2938                0
2939            } else {
2940                line.rendered_index_for_source_index(range.start)
2941            };
2942            let end = if range.end > line.source_end {
2943                line.rendered_index_for_source_index(line.source_end)
2944            } else {
2945                line.rendered_index_for_source_index(range.end)
2946            }
2947            .min(text.len());
2948
2949            accumulator.push_str(&text[start..end]);
2950            accumulator.push('\n');
2951        }
2952        // Remove trailing newline
2953        accumulator.pop();
2954        accumulator
2955    }
2956
2957    fn link_for_source_index(&self, source_index: usize) -> Option<&RenderedLink> {
2958        self.links
2959            .iter()
2960            .find(|link| link.source_range.contains(&source_index))
2961    }
2962
2963    fn footnote_ref_for_source_index(&self, source_index: usize) -> Option<&RenderedFootnoteRef> {
2964        self.footnote_refs
2965            .iter()
2966            .find(|fref| fref.source_range.contains(&source_index))
2967    }
2968}
2969
2970#[cfg(test)]
2971mod tests {
2972    use super::*;
2973    use gpui::{TestAppContext, size};
2974    use language::{Language, LanguageConfig, LanguageMatcher};
2975    use std::sync::Arc;
2976
2977    fn ensure_theme_initialized(cx: &mut TestAppContext) {
2978        cx.update(|cx| {
2979            if !cx.has_global::<settings::SettingsStore>() {
2980                settings::init(cx);
2981            }
2982            if !cx.has_global::<theme::GlobalTheme>() {
2983                theme_settings::init(theme::LoadThemes::JustBase, cx);
2984            }
2985        });
2986    }
2987
2988    #[gpui::test]
2989    fn test_mappings(cx: &mut TestAppContext) {
2990        // Formatting.
2991        assert_mappings(
2992            &render_markdown("He*l*lo", cx),
2993            vec![vec![(0, 0), (1, 1), (2, 3), (3, 5), (4, 6), (5, 7)]],
2994        );
2995
2996        // Multiple lines.
2997        assert_mappings(
2998            &render_markdown("Hello\n\nWorld", cx),
2999            vec![
3000                vec![(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)],
3001                vec![(0, 7), (1, 8), (2, 9), (3, 10), (4, 11), (5, 12)],
3002            ],
3003        );
3004
3005        // Multi-byte characters.
3006        assert_mappings(
3007            &render_markdown("αβγ\n\nδεζ", cx),
3008            vec![
3009                vec![(0, 0), (2, 2), (4, 4), (6, 6)],
3010                vec![(0, 8), (2, 10), (4, 12), (6, 14)],
3011            ],
3012        );
3013
3014        // Smart quotes.
3015        assert_mappings(&render_markdown("\"", cx), vec![vec![(0, 0), (3, 1)]]);
3016        assert_mappings(
3017            &render_markdown("\"hey\"", cx),
3018            vec![vec![(0, 0), (3, 1), (4, 2), (5, 3), (6, 4), (9, 5)]],
3019        );
3020
3021        // HTML Comments are ignored
3022        assert_mappings(
3023            &render_markdown(
3024                "<!--\nrdoc-file=string.c\n- str.intern   -> symbol\n- str.to_sym   -> symbol\n-->\nReturns",
3025                cx,
3026            ),
3027            vec![vec![
3028                (0, 78),
3029                (1, 79),
3030                (2, 80),
3031                (3, 81),
3032                (4, 82),
3033                (5, 83),
3034                (6, 84),
3035            ]],
3036        );
3037    }
3038
3039    fn render_markdown(markdown: &str, cx: &mut TestAppContext) -> RenderedText {
3040        render_markdown_with_language_registry(markdown, None, cx)
3041    }
3042
3043    fn render_markdown_with_language_registry(
3044        markdown: &str,
3045        language_registry: Option<Arc<LanguageRegistry>>,
3046        cx: &mut TestAppContext,
3047    ) -> RenderedText {
3048        render_markdown_with_options(markdown, language_registry, MarkdownOptions::default(), cx)
3049    }
3050
3051    fn render_markdown_with_options(
3052        markdown: &str,
3053        language_registry: Option<Arc<LanguageRegistry>>,
3054        options: MarkdownOptions,
3055        cx: &mut TestAppContext,
3056    ) -> RenderedText {
3057        struct TestWindow;
3058
3059        impl Render for TestWindow {
3060            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
3061                div()
3062            }
3063        }
3064
3065        ensure_theme_initialized(cx);
3066
3067        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
3068        let markdown = cx.new(|cx| {
3069            Markdown::new_with_options(
3070                markdown.to_string().into(),
3071                language_registry,
3072                None,
3073                options,
3074                cx,
3075            )
3076        });
3077        cx.run_until_parked();
3078        let (rendered, _) = cx.draw(
3079            Default::default(),
3080            size(px(600.0), px(600.0)),
3081            |_window, _cx| {
3082                MarkdownElement::new(markdown, MarkdownStyle::default()).code_block_renderer(
3083                    CodeBlockRenderer::Default {
3084                        copy_button_visibility: CopyButtonVisibility::Hidden,
3085                        border: false,
3086                    },
3087                )
3088            },
3089        );
3090        rendered.text
3091    }
3092
3093    #[gpui::test]
3094    fn test_surrounding_word_range(cx: &mut TestAppContext) {
3095        let rendered = render_markdown("Hello world tesεζ", cx);
3096
3097        // Test word selection for "Hello"
3098        let word_range = rendered.surrounding_word_range(2); // Simulate click on 'l' in "Hello"
3099        let selected_text = rendered.text_for_range(word_range);
3100        assert_eq!(selected_text, "Hello");
3101
3102        // Test word selection for "world"
3103        let word_range = rendered.surrounding_word_range(7); // Simulate click on 'o' in "world"
3104        let selected_text = rendered.text_for_range(word_range);
3105        assert_eq!(selected_text, "world");
3106
3107        // Test word selection for "tesεζ"
3108        let word_range = rendered.surrounding_word_range(14); // Simulate click on 's' in "tesεζ"
3109        let selected_text = rendered.text_for_range(word_range);
3110        assert_eq!(selected_text, "tesεζ");
3111
3112        // Test word selection at word boundary (space)
3113        let word_range = rendered.surrounding_word_range(5); // Simulate click on space between "Hello" and "world", expect highlighting word to the left
3114        let selected_text = rendered.text_for_range(word_range);
3115        assert_eq!(selected_text, "Hello");
3116    }
3117
3118    #[gpui::test]
3119    fn test_surrounding_line_range(cx: &mut TestAppContext) {
3120        let rendered = render_markdown("First line\n\nSecond line\n\nThird lineεζ", cx);
3121
3122        // Test getting line range for first line
3123        let line_range = rendered.surrounding_line_range(5); // Simulate click somewhere in first line
3124        let selected_text = rendered.text_for_range(line_range);
3125        assert_eq!(selected_text, "First line");
3126
3127        // Test getting line range for second line
3128        let line_range = rendered.surrounding_line_range(13); // Simulate click at beginning in second line
3129        let selected_text = rendered.text_for_range(line_range);
3130        assert_eq!(selected_text, "Second line");
3131
3132        // Test getting line range for third line
3133        let line_range = rendered.surrounding_line_range(37); // Simulate click at end of third line with multi-byte chars
3134        let selected_text = rendered.text_for_range(line_range);
3135        assert_eq!(selected_text, "Third lineεζ");
3136    }
3137
3138    #[gpui::test]
3139    fn test_selection_head_movement(cx: &mut TestAppContext) {
3140        let rendered = render_markdown("Hello world test", cx);
3141
3142        let mut selection = Selection {
3143            start: 5,
3144            end: 5,
3145            reversed: false,
3146            pending: false,
3147            mode: SelectMode::Character,
3148        };
3149
3150        // Test forward selection
3151        selection.set_head(10, &rendered);
3152        assert_eq!(selection.start, 5);
3153        assert_eq!(selection.end, 10);
3154        assert!(!selection.reversed);
3155        assert_eq!(selection.tail(), 5);
3156
3157        // Test backward selection
3158        selection.set_head(2, &rendered);
3159        assert_eq!(selection.start, 2);
3160        assert_eq!(selection.end, 5);
3161        assert!(selection.reversed);
3162        assert_eq!(selection.tail(), 5);
3163
3164        // Test forward selection again from reversed state
3165        selection.set_head(15, &rendered);
3166        assert_eq!(selection.start, 5);
3167        assert_eq!(selection.end, 15);
3168        assert!(!selection.reversed);
3169        assert_eq!(selection.tail(), 5);
3170    }
3171
3172    #[gpui::test]
3173    fn test_word_selection_drag(cx: &mut TestAppContext) {
3174        let rendered = render_markdown("Hello world test", cx);
3175
3176        // Start with a simulated double-click on "world" (index 6-10)
3177        let word_range = rendered.surrounding_word_range(7); // Click on 'o' in "world"
3178        let mut selection = Selection {
3179            start: word_range.start,
3180            end: word_range.end,
3181            reversed: false,
3182            pending: true,
3183            mode: SelectMode::Word(word_range),
3184        };
3185
3186        // Drag forward to "test" - should expand selection to include "test"
3187        selection.set_head(13, &rendered); // Index in "test"
3188        assert_eq!(selection.start, 6); // Start of "world"
3189        assert_eq!(selection.end, 16); // End of "test"
3190        assert!(!selection.reversed);
3191        let selected_text = rendered.text_for_range(selection.start..selection.end);
3192        assert_eq!(selected_text, "world test");
3193
3194        // Drag backward to "Hello" - should expand selection to include "Hello"
3195        selection.set_head(2, &rendered); // Index in "Hello"
3196        assert_eq!(selection.start, 0); // Start of "Hello"
3197        assert_eq!(selection.end, 11); // End of "world" (original selection)
3198        assert!(selection.reversed);
3199        let selected_text = rendered.text_for_range(selection.start..selection.end);
3200        assert_eq!(selected_text, "Hello world");
3201
3202        // Drag back within original word - should revert to original selection
3203        selection.set_head(8, &rendered); // Back within "world"
3204        assert_eq!(selection.start, 6); // Start of "world"
3205        assert_eq!(selection.end, 11); // End of "world"
3206        assert!(!selection.reversed);
3207        let selected_text = rendered.text_for_range(selection.start..selection.end);
3208        assert_eq!(selected_text, "world");
3209    }
3210
3211    #[gpui::test]
3212    fn test_selection_with_markdown_formatting(cx: &mut TestAppContext) {
3213        let rendered = render_markdown(
3214            "This is **bold** text, this is *italic* text, use `code` here",
3215            cx,
3216        );
3217        let word_range = rendered.surrounding_word_range(10); // Inside "bold"
3218        let selected_text = rendered.text_for_range(word_range);
3219        assert_eq!(selected_text, "bold");
3220
3221        let word_range = rendered.surrounding_word_range(32); // Inside "italic"
3222        let selected_text = rendered.text_for_range(word_range);
3223        assert_eq!(selected_text, "italic");
3224
3225        let word_range = rendered.surrounding_word_range(51); // Inside "code"
3226        let selected_text = rendered.text_for_range(word_range);
3227        assert_eq!(selected_text, "code");
3228    }
3229
3230    #[gpui::test]
3231    fn test_table_column_selection(cx: &mut TestAppContext) {
3232        let rendered = render_markdown("| a | b |\n|---|---|\n| c | d |", cx);
3233
3234        assert!(rendered.lines.len() >= 2);
3235        let first_bounds = rendered.lines[0].layout.bounds();
3236        let second_bounds = rendered.lines[1].layout.bounds();
3237
3238        let first_index = match rendered.source_index_for_position(first_bounds.center()) {
3239            Ok(index) | Err(index) => index,
3240        };
3241        let second_index = match rendered.source_index_for_position(second_bounds.center()) {
3242            Ok(index) | Err(index) => index,
3243        };
3244
3245        let first_word = rendered.text_for_range(rendered.surrounding_word_range(first_index));
3246        let second_word = rendered.text_for_range(rendered.surrounding_word_range(second_index));
3247
3248        assert_eq!(first_word, "a");
3249        assert_eq!(second_word, "b");
3250    }
3251
3252    #[test]
3253    fn test_table_checkbox_detection() {
3254        let md = "| Done |\n|------|\n| [x] |\n| [ ] |";
3255        let events = crate::parser::parse_markdown_with_options(md, false, false).events;
3256
3257        let mut in_table = false;
3258        let mut cell_texts: Vec<String> = Vec::new();
3259        let mut current_cell = String::new();
3260
3261        for (range, event) in &events {
3262            match event {
3263                MarkdownEvent::Start(MarkdownTag::Table(_)) => in_table = true,
3264                MarkdownEvent::End(MarkdownTagEnd::Table) => in_table = false,
3265                MarkdownEvent::Start(MarkdownTag::TableCell) => current_cell.clear(),
3266                MarkdownEvent::End(MarkdownTagEnd::TableCell) => {
3267                    if in_table {
3268                        cell_texts.push(current_cell.clone());
3269                    }
3270                }
3271                MarkdownEvent::Text if in_table => {
3272                    current_cell.push_str(&md[range.clone()]);
3273                }
3274                _ => {}
3275            }
3276        }
3277
3278        let checkbox_cells: Vec<&String> = cell_texts
3279            .iter()
3280            .filter(|t| {
3281                let trimmed = t.trim();
3282                trimmed == "[x]" || trimmed == "[X]" || trimmed == "[ ]"
3283            })
3284            .collect();
3285        assert_eq!(
3286            checkbox_cells.len(),
3287            2,
3288            "Expected 2 checkbox cells, got: {cell_texts:?}"
3289        );
3290        assert_eq!(checkbox_cells[0].trim(), "[x]");
3291        assert_eq!(checkbox_cells[1].trim(), "[ ]");
3292    }
3293
3294    #[gpui::test]
3295    fn test_inline_code_word_selection_excludes_backticks(cx: &mut TestAppContext) {
3296        // Test that double-clicking on inline code selects just the code content,
3297        // not the backticks. This verifies the fix for the bug where selecting
3298        // inline code would include the trailing backtick.
3299        let rendered = render_markdown("use `blah` here", cx);
3300
3301        // Source layout: "use `blah` here"
3302        //                 0123456789...
3303        // The inline code "blah" is at source positions 5-8 (content range 5..9)
3304
3305        // Click inside "blah" - should select just "blah", not "blah`"
3306        let word_range = rendered.surrounding_word_range(6); // 'l' in "blah"
3307
3308        // text_for_range extracts from the rendered text (without backticks), so it
3309        // would return "blah" even with a wrong source range. We check it anyway.
3310        let selected_text = rendered.text_for_range(word_range.clone());
3311        assert_eq!(selected_text, "blah");
3312
3313        // The source range is what matters for copy_as_markdown and selected_text,
3314        // which extract directly from the source. With the bug, this would be 5..10
3315        // which includes the closing backtick at position 9.
3316        assert_eq!(word_range, 5..9);
3317    }
3318
3319    #[gpui::test]
3320    fn test_surrounding_word_range_respects_word_characters(cx: &mut TestAppContext) {
3321        let rendered = render_markdown("foo.bar() baz", cx);
3322
3323        // Double clicking on 'f' in "foo" - should select just "foo"
3324        let word_range = rendered.surrounding_word_range(0);
3325        let selected_text = rendered.text_for_range(word_range);
3326        assert_eq!(selected_text, "foo");
3327
3328        // Double clicking on 'b' in "bar" - should select just "bar"
3329        let word_range = rendered.surrounding_word_range(4);
3330        let selected_text = rendered.text_for_range(word_range);
3331        assert_eq!(selected_text, "bar");
3332
3333        // Double clicking on 'b' in "baz" - should select "baz"
3334        let word_range = rendered.surrounding_word_range(10);
3335        let selected_text = rendered.text_for_range(word_range);
3336        assert_eq!(selected_text, "baz");
3337
3338        // Double clicking selects word characters in code blocks
3339        let javascript_language = Arc::new(Language::new(
3340            LanguageConfig {
3341                name: "JavaScript".into(),
3342                matcher: LanguageMatcher {
3343                    path_suffixes: vec!["js".to_string()],
3344                    ..Default::default()
3345                },
3346                word_characters: ['$', '#'].into_iter().collect(),
3347                ..Default::default()
3348            },
3349            None,
3350        ));
3351
3352        let language_registry = Arc::new(LanguageRegistry::test(cx.executor()));
3353        language_registry.add(javascript_language);
3354
3355        let rendered = render_markdown_with_language_registry(
3356            "```javascript\n$foo #bar\n```",
3357            Some(language_registry),
3358            cx,
3359        );
3360
3361        let word_range = rendered.surrounding_word_range(14);
3362        let selected_text = rendered.text_for_range(word_range);
3363        assert_eq!(selected_text, "$foo");
3364
3365        let word_range = rendered.surrounding_word_range(19);
3366        let selected_text = rendered.text_for_range(word_range);
3367        assert_eq!(selected_text, "#bar");
3368    }
3369
3370    #[gpui::test]
3371    fn test_all_selection(cx: &mut TestAppContext) {
3372        let rendered = render_markdown("Hello world\n\nThis is a test\n\nwith multiple lines", cx);
3373
3374        let total_length = rendered
3375            .lines
3376            .last()
3377            .map(|line| line.source_end)
3378            .unwrap_or(0);
3379
3380        let mut selection = Selection {
3381            start: 0,
3382            end: total_length,
3383            reversed: false,
3384            pending: true,
3385            mode: SelectMode::All,
3386        };
3387
3388        selection.set_head(5, &rendered); // Try to set head in middle
3389        assert_eq!(selection.start, 0);
3390        assert_eq!(selection.end, total_length);
3391        assert!(!selection.reversed);
3392
3393        selection.set_head(25, &rendered); // Try to set head near end
3394        assert_eq!(selection.start, 0);
3395        assert_eq!(selection.end, total_length);
3396        assert!(!selection.reversed);
3397
3398        let selected_text = rendered.text_for_range(selection.start..selection.end);
3399        assert_eq!(
3400            selected_text,
3401            "Hello world\nThis is a test\nwith multiple lines"
3402        );
3403    }
3404
3405    fn nbsp(n: usize) -> String {
3406        "\u{00A0}".repeat(n)
3407    }
3408
3409    #[test]
3410    fn test_escape_plain_text() {
3411        assert_eq!(Markdown::escape("hello world"), "hello world");
3412        assert_eq!(Markdown::escape(""), "");
3413        assert_eq!(Markdown::escape("café ☕ naïve"), "café ☕ naïve");
3414    }
3415
3416    #[test]
3417    fn test_escape_punctuation() {
3418        assert_eq!(Markdown::escape("hello `world`"), r"hello \`world\`");
3419        assert_eq!(Markdown::escape("a|b"), r"a\|b");
3420    }
3421
3422    #[test]
3423    fn test_escape_leading_spaces() {
3424        assert_eq!(Markdown::escape("    hello"), [&nbsp(4), "hello"].concat());
3425        assert_eq!(
3426            Markdown::escape("    | { a: string }"),
3427            [&nbsp(4), r"\| \{ a\: string \}"].concat()
3428        );
3429        assert_eq!(
3430            Markdown::escape("  first\n  second"),
3431            [&nbsp(2), "first\n\n", &nbsp(2), "second"].concat()
3432        );
3433        assert_eq!(Markdown::escape("hello   world"), "hello   world");
3434    }
3435
3436    #[test]
3437    fn test_escape_leading_tabs() {
3438        assert_eq!(Markdown::escape("\thello"), [&nbsp(4), "hello"].concat());
3439        assert_eq!(
3440            Markdown::escape("hello\n\t\tindented"),
3441            ["hello\n\n", &nbsp(8), "indented"].concat()
3442        );
3443        assert_eq!(
3444            Markdown::escape(" \t hello"),
3445            [&nbsp(1 + 4 + 1), "hello"].concat()
3446        );
3447        assert_eq!(Markdown::escape("hello\tworld"), "hello\tworld");
3448    }
3449
3450    #[test]
3451    fn test_escape_newlines() {
3452        assert_eq!(Markdown::escape("a\nb"), "a\n\nb");
3453        assert_eq!(Markdown::escape("a\n\nb"), "a\n\n\n\nb");
3454        assert_eq!(Markdown::escape("\nhello"), "\n\nhello");
3455    }
3456
3457    #[test]
3458    fn test_escape_multiline_diagnostic() {
3459        assert_eq!(
3460            Markdown::escape("    | { a: string }\n    | { b: number }"),
3461            [
3462                &nbsp(4),
3463                r"\| \{ a\: string \}",
3464                "\n\n",
3465                &nbsp(4),
3466                r"\| \{ b\: number \}",
3467            ]
3468            .concat()
3469        );
3470    }
3471
3472    fn has_code_block(markdown: &str) -> bool {
3473        let parsed_data = parse_markdown_with_options(markdown, false, false);
3474        parsed_data
3475            .events
3476            .iter()
3477            .any(|(_, event)| matches!(event, MarkdownEvent::Start(MarkdownTag::CodeBlock { .. })))
3478    }
3479
3480    #[test]
3481    fn test_escape_output_len_matches_precomputed() {
3482        let cases = [
3483            "",
3484            "hello world",
3485            "hello `world`",
3486            "    hello",
3487            "    | { a: string }",
3488            "\thello",
3489            "hello\n\t\tindented",
3490            " \t hello",
3491            "hello\tworld",
3492            "a\nb",
3493            "a\n\nb",
3494            "\nhello",
3495            "    | { a: string }\n    | { b: number }",
3496            "café ☕ naïve",
3497        ];
3498        for input in cases {
3499            let mut escaper = MarkdownEscaper::new();
3500            let precomputed: usize = input.bytes().map(|b| escaper.next(b).output_len()).sum();
3501
3502            let mut escaper = MarkdownEscaper::new();
3503            let mut output = String::new();
3504            for c in input.chars() {
3505                escaper.next(c as u8).write_to(c, &mut output);
3506            }
3507
3508            assert_eq!(precomputed, output.len(), "length mismatch for {:?}", input);
3509        }
3510    }
3511
3512    #[test]
3513    fn test_escape_prevents_code_block() {
3514        let diagnostic = "    | { a: string }";
3515        assert!(has_code_block(diagnostic));
3516        assert!(!has_code_block(&Markdown::escape(diagnostic)));
3517    }
3518
3519    #[track_caller]
3520    fn assert_mappings(rendered: &RenderedText, expected: Vec<Vec<(usize, usize)>>) {
3521        assert_eq!(rendered.lines.len(), expected.len(), "line count mismatch");
3522        for (line_ix, line_mappings) in expected.into_iter().enumerate() {
3523            let line = &rendered.lines[line_ix];
3524
3525            assert!(
3526                line.source_mappings.windows(2).all(|mappings| {
3527                    mappings[0].source_index < mappings[1].source_index
3528                        && mappings[0].rendered_index < mappings[1].rendered_index
3529                }),
3530                "line {} has duplicate mappings: {:?}",
3531                line_ix,
3532                line.source_mappings
3533            );
3534
3535            for (rendered_ix, source_ix) in line_mappings {
3536                assert_eq!(
3537                    line.source_index_for_rendered_index(rendered_ix),
3538                    source_ix,
3539                    "line {}, rendered_ix {}",
3540                    line_ix,
3541                    rendered_ix
3542                );
3543
3544                assert_eq!(
3545                    line.rendered_index_for_source_index(source_ix),
3546                    rendered_ix,
3547                    "line {}, source_ix {}",
3548                    line_ix,
3549                    source_ix
3550                );
3551            }
3552        }
3553    }
3554}