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            code_block: StyleRefinement {
 161                padding: EdgesRefinement {
 162                    top: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 163                    left: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 164                    right: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 165                    bottom: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 166                },
 167                margin: EdgesRefinement {
 168                    top: Some(Length::Definite(px(8.).into())),
 169                    left: Some(Length::Definite(px(0.).into())),
 170                    right: Some(Length::Definite(px(0.).into())),
 171                    bottom: Some(Length::Definite(px(12.).into())),
 172                },
 173                border_style: Some(BorderStyle::Solid),
 174                border_widths: EdgesRefinement {
 175                    top: Some(AbsoluteLength::Pixels(px(1.))),
 176                    left: Some(AbsoluteLength::Pixels(px(1.))),
 177                    right: Some(AbsoluteLength::Pixels(px(1.))),
 178                    bottom: Some(AbsoluteLength::Pixels(px(1.))),
 179                },
 180                border_color: Some(colors.border_variant),
 181                background: Some(colors.editor_background.into()),
 182                text: TextStyleRefinement {
 183                    font_family: Some(theme_settings.buffer_font.family.clone()),
 184                    font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 185                    font_features: Some(theme_settings.buffer_font.features.clone()),
 186                    font_size: Some(buffer_font_size.into()),
 187                    font_weight: Some(buffer_font_weight),
 188                    ..Default::default()
 189                },
 190                ..Default::default()
 191            },
 192            inline_code: TextStyleRefinement {
 193                font_family: Some(theme_settings.buffer_font.family.clone()),
 194                font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 195                font_features: Some(theme_settings.buffer_font.features.clone()),
 196                font_size: Some(buffer_font_size.into()),
 197                font_weight: Some(buffer_font_weight),
 198                background_color: Some(colors.editor_foreground.opacity(0.08)),
 199                ..Default::default()
 200            },
 201            link: TextStyleRefinement {
 202                background_color: Some(colors.editor_foreground.opacity(0.025)),
 203                color: Some(colors.text_accent),
 204                underline: Some(UnderlineStyle {
 205                    color: Some(colors.text_accent.opacity(0.5)),
 206                    thickness: px(1.),
 207                    ..Default::default()
 208                }),
 209                ..Default::default()
 210            },
 211            ..Default::default()
 212        }
 213    }
 214
 215    pub fn with_muted_text(mut self, cx: &App) -> Self {
 216        let colors = cx.theme().colors();
 217        self.base_text_style.color = colors.text_muted;
 218        self
 219    }
 220}
 221
 222pub struct Markdown {
 223    source: SharedString,
 224    selection: Selection,
 225    pressed_link: Option<RenderedLink>,
 226    pressed_footnote_ref: Option<RenderedFootnoteRef>,
 227    autoscroll_request: Option<usize>,
 228    active_root_block: Option<usize>,
 229    parsed_markdown: ParsedMarkdown,
 230    images_by_source_offset: HashMap<usize, Arc<Image>>,
 231    should_reparse: bool,
 232    pending_parse: Option<Task<()>>,
 233    focus_handle: FocusHandle,
 234    language_registry: Option<Arc<LanguageRegistry>>,
 235    fallback_code_block_language: Option<LanguageName>,
 236    options: MarkdownOptions,
 237    mermaid_state: MermaidState,
 238    copied_code_blocks: HashSet<ElementId>,
 239    code_block_scroll_handles: BTreeMap<usize, ScrollHandle>,
 240    context_menu_link: Option<SharedString>,
 241    context_menu_selected_text: Option<String>,
 242    search_highlights: Vec<Range<usize>>,
 243    active_search_highlight: Option<usize>,
 244}
 245
 246#[derive(Clone, Copy, Default)]
 247pub struct MarkdownOptions {
 248    pub parse_links_only: bool,
 249    pub parse_html: bool,
 250    pub render_mermaid_diagrams: bool,
 251    pub parse_heading_slugs: bool,
 252}
 253
 254#[derive(Clone, Copy, PartialEq, Eq)]
 255pub enum CopyButtonVisibility {
 256    Hidden,
 257    AlwaysVisible,
 258    VisibleOnHover,
 259}
 260
 261pub enum CodeBlockRenderer {
 262    Default {
 263        copy_button_visibility: CopyButtonVisibility,
 264        border: bool,
 265    },
 266    Custom {
 267        render: CodeBlockRenderFn,
 268        /// A function that can modify the parent container after the code block
 269        /// content has been appended as a child element.
 270        transform: Option<CodeBlockTransformFn>,
 271    },
 272}
 273
 274pub type CodeBlockRenderFn = Arc<
 275    dyn Fn(
 276        &CodeBlockKind,
 277        &ParsedMarkdown,
 278        Range<usize>,
 279        CodeBlockMetadata,
 280        &mut Window,
 281        &App,
 282    ) -> Div,
 283>;
 284
 285pub type CodeBlockTransformFn =
 286    Arc<dyn Fn(AnyDiv, Range<usize>, CodeBlockMetadata, &mut Window, &App) -> AnyDiv>;
 287
 288actions!(
 289    markdown,
 290    [
 291        /// Copies the selected text to the clipboard.
 292        Copy,
 293        /// Copies the selected text as markdown to the clipboard.
 294        CopyAsMarkdown
 295    ]
 296);
 297
 298enum EscapeAction {
 299    PassThrough,
 300    Nbsp(usize),
 301    DoubleNewline,
 302    PrefixBackslash,
 303}
 304
 305impl EscapeAction {
 306    fn output_len(&self) -> usize {
 307        match self {
 308            Self::PassThrough => 1,
 309            Self::Nbsp(count) => count * '\u{00A0}'.len_utf8(),
 310            Self::DoubleNewline => 2,
 311            Self::PrefixBackslash => 2,
 312        }
 313    }
 314
 315    fn write_to(&self, c: char, output: &mut String) {
 316        match self {
 317            Self::PassThrough => output.push(c),
 318            Self::Nbsp(count) => {
 319                for _ in 0..*count {
 320                    output.push('\u{00A0}');
 321                }
 322            }
 323            Self::DoubleNewline => {
 324                output.push('\n');
 325                output.push('\n');
 326            }
 327            Self::PrefixBackslash => {
 328                // '\\' is a single backslash in Rust, e.g. '|' -> '\|'
 329                output.push('\\');
 330                output.push(c);
 331            }
 332        }
 333    }
 334}
 335
 336// Valid to operate on raw bytes since multi-byte UTF-8
 337// sequences never contain ASCII-range bytes.
 338struct MarkdownEscaper {
 339    in_leading_whitespace: bool,
 340}
 341
 342impl MarkdownEscaper {
 343    const TAB_SIZE: usize = 4;
 344
 345    fn new() -> Self {
 346        Self {
 347            in_leading_whitespace: true,
 348        }
 349    }
 350
 351    fn next(&mut self, byte: u8) -> EscapeAction {
 352        let action = if self.in_leading_whitespace && byte == b'\t' {
 353            EscapeAction::Nbsp(Self::TAB_SIZE)
 354        } else if self.in_leading_whitespace && byte == b' ' {
 355            EscapeAction::Nbsp(1)
 356        } else if byte == b'\n' {
 357            EscapeAction::DoubleNewline
 358        } else if byte.is_ascii_punctuation() {
 359            EscapeAction::PrefixBackslash
 360        } else {
 361            EscapeAction::PassThrough
 362        };
 363
 364        self.in_leading_whitespace =
 365            byte == b'\n' || (self.in_leading_whitespace && (byte == b' ' || byte == b'\t'));
 366        action
 367    }
 368}
 369
 370impl Markdown {
 371    pub fn new(
 372        source: SharedString,
 373        language_registry: Option<Arc<LanguageRegistry>>,
 374        fallback_code_block_language: Option<LanguageName>,
 375        cx: &mut Context<Self>,
 376    ) -> Self {
 377        Self::new_with_options(
 378            source,
 379            language_registry,
 380            fallback_code_block_language,
 381            MarkdownOptions::default(),
 382            cx,
 383        )
 384    }
 385
 386    pub fn new_with_options(
 387        source: SharedString,
 388        language_registry: Option<Arc<LanguageRegistry>>,
 389        fallback_code_block_language: Option<LanguageName>,
 390        options: MarkdownOptions,
 391        cx: &mut Context<Self>,
 392    ) -> Self {
 393        let focus_handle = cx.focus_handle();
 394        let mut this = Self {
 395            source,
 396            selection: Selection::default(),
 397            pressed_link: None,
 398            pressed_footnote_ref: None,
 399            autoscroll_request: None,
 400            active_root_block: None,
 401            should_reparse: false,
 402            images_by_source_offset: Default::default(),
 403            parsed_markdown: ParsedMarkdown::default(),
 404            pending_parse: None,
 405            focus_handle,
 406            language_registry,
 407            fallback_code_block_language,
 408            options,
 409            mermaid_state: MermaidState::default(),
 410            copied_code_blocks: HashSet::default(),
 411            code_block_scroll_handles: BTreeMap::default(),
 412            context_menu_link: None,
 413            context_menu_selected_text: None,
 414            search_highlights: Vec::new(),
 415            active_search_highlight: None,
 416        };
 417        this.parse(cx);
 418        this
 419    }
 420
 421    pub fn new_text(source: SharedString, cx: &mut Context<Self>) -> Self {
 422        Self::new_with_options(
 423            source,
 424            None,
 425            None,
 426            MarkdownOptions {
 427                parse_links_only: true,
 428                ..Default::default()
 429            },
 430            cx,
 431        )
 432    }
 433
 434    fn code_block_scroll_handle(&mut self, id: usize) -> ScrollHandle {
 435        self.code_block_scroll_handles
 436            .entry(id)
 437            .or_insert_with(ScrollHandle::new)
 438            .clone()
 439    }
 440
 441    fn retain_code_block_scroll_handles(&mut self, ids: &HashSet<usize>) {
 442        self.code_block_scroll_handles
 443            .retain(|id, _| ids.contains(id));
 444    }
 445
 446    fn clear_code_block_scroll_handles(&mut self) {
 447        self.code_block_scroll_handles.clear();
 448    }
 449
 450    fn autoscroll_code_block(&self, source_index: usize, cursor_position: Point<Pixels>) {
 451        let Some((_, scroll_handle)) = self
 452            .code_block_scroll_handles
 453            .range(..=source_index)
 454            .next_back()
 455        else {
 456            return;
 457        };
 458
 459        let bounds = scroll_handle.bounds();
 460        if cursor_position.y < bounds.top() || cursor_position.y > bounds.bottom() {
 461            return;
 462        }
 463
 464        let horizontal_delta = if cursor_position.x < bounds.left() {
 465            bounds.left() - cursor_position.x
 466        } else if cursor_position.x > bounds.right() {
 467            bounds.right() - cursor_position.x
 468        } else {
 469            return;
 470        };
 471
 472        let offset = scroll_handle.offset();
 473        scroll_handle.set_offset(point(offset.x + horizontal_delta, offset.y));
 474    }
 475
 476    pub fn is_parsing(&self) -> bool {
 477        self.pending_parse.is_some()
 478    }
 479
 480    pub fn scroll_to_heading(&mut self, slug: &str, cx: &mut Context<Self>) -> Option<usize> {
 481        if let Some(source_index) = self.parsed_markdown.heading_slugs.get(slug).copied() {
 482            self.autoscroll_request = Some(source_index);
 483            cx.notify();
 484            Some(source_index)
 485        } else {
 486            None
 487        }
 488    }
 489
 490    pub fn source(&self) -> &str {
 491        &self.source
 492    }
 493
 494    pub fn append(&mut self, text: &str, cx: &mut Context<Self>) {
 495        self.source = SharedString::new(self.source.to_string() + text);
 496        self.parse(cx);
 497    }
 498
 499    pub fn replace(&mut self, source: impl Into<SharedString>, cx: &mut Context<Self>) {
 500        self.source = source.into();
 501        self.parse(cx);
 502    }
 503
 504    pub fn request_autoscroll_to_source_index(
 505        &mut self,
 506        source_index: usize,
 507        cx: &mut Context<Self>,
 508    ) {
 509        self.autoscroll_request = Some(source_index);
 510        cx.refresh_windows();
 511    }
 512
 513    fn footnote_definition_content_start(&self, label: &SharedString) -> Option<usize> {
 514        self.parsed_markdown
 515            .footnote_definitions
 516            .get(label)
 517            .copied()
 518    }
 519
 520    pub fn set_active_root_for_source_index(
 521        &mut self,
 522        source_index: Option<usize>,
 523        cx: &mut Context<Self>,
 524    ) {
 525        let active_root_block =
 526            source_index.and_then(|index| self.parsed_markdown.root_block_for_source_index(index));
 527        if self.active_root_block == active_root_block {
 528            return;
 529        }
 530
 531        self.active_root_block = active_root_block;
 532        cx.notify();
 533    }
 534
 535    pub fn reset(&mut self, source: SharedString, cx: &mut Context<Self>) {
 536        if source == self.source() {
 537            return;
 538        }
 539        self.source = source;
 540        self.selection = Selection::default();
 541        self.autoscroll_request = None;
 542        self.pending_parse = None;
 543        self.should_reparse = false;
 544        self.search_highlights.clear();
 545        self.active_search_highlight = None;
 546        // Don't clear parsed_markdown here - keep existing content visible until new parse completes
 547        self.parse(cx);
 548    }
 549
 550    #[cfg(any(test, feature = "test-support"))]
 551    pub fn parsed_markdown(&self) -> &ParsedMarkdown {
 552        &self.parsed_markdown
 553    }
 554
 555    pub fn escape(s: &str) -> Cow<'_, str> {
 556        let output_len: usize = {
 557            let mut escaper = MarkdownEscaper::new();
 558            s.bytes().map(|byte| escaper.next(byte).output_len()).sum()
 559        };
 560
 561        if output_len == s.len() {
 562            return s.into();
 563        }
 564
 565        let mut escaper = MarkdownEscaper::new();
 566        let mut output = String::with_capacity(output_len);
 567        for c in s.chars() {
 568            escaper.next(c as u8).write_to(c, &mut output);
 569        }
 570        output.into()
 571    }
 572
 573    pub fn selected_text(&self) -> Option<String> {
 574        if self.selection.end <= self.selection.start {
 575            None
 576        } else {
 577            Some(self.source[self.selection.start..self.selection.end].to_string())
 578        }
 579    }
 580
 581    pub fn set_search_highlights(
 582        &mut self,
 583        highlights: Vec<Range<usize>>,
 584        active: Option<usize>,
 585        cx: &mut Context<Self>,
 586    ) {
 587        self.search_highlights = highlights;
 588        self.active_search_highlight = active;
 589        cx.notify();
 590    }
 591
 592    pub fn clear_search_highlights(&mut self, cx: &mut Context<Self>) {
 593        if !self.search_highlights.is_empty() || self.active_search_highlight.is_some() {
 594            self.search_highlights.clear();
 595            self.active_search_highlight = None;
 596            cx.notify();
 597        }
 598    }
 599
 600    pub fn set_active_search_highlight(&mut self, active: Option<usize>, cx: &mut Context<Self>) {
 601        if self.active_search_highlight != active {
 602            self.active_search_highlight = active;
 603            cx.notify();
 604        }
 605    }
 606
 607    pub fn search_highlights(&self) -> &[Range<usize>] {
 608        &self.search_highlights
 609    }
 610
 611    pub fn active_search_highlight(&self) -> Option<usize> {
 612        self.active_search_highlight
 613    }
 614
 615    fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
 616        if self.selection.end <= self.selection.start {
 617            return;
 618        }
 619        let text = text.text_for_range(self.selection.start..self.selection.end);
 620        cx.write_to_clipboard(ClipboardItem::new_string(text));
 621    }
 622
 623    fn copy_as_markdown(&mut self, _: &mut Window, cx: &mut Context<Self>) {
 624        if let Some(text) = self.context_menu_selected_text.take() {
 625            cx.write_to_clipboard(ClipboardItem::new_string(text));
 626            return;
 627        }
 628        if self.selection.end <= self.selection.start {
 629            return;
 630        }
 631        let text = self.source[self.selection.start..self.selection.end].to_string();
 632        cx.write_to_clipboard(ClipboardItem::new_string(text));
 633    }
 634
 635    fn capture_for_context_menu(&mut self, link: Option<SharedString>) {
 636        self.context_menu_selected_text = self.selected_text();
 637        self.context_menu_link = link;
 638    }
 639
 640    /// Returns the URL of the link that was most recently right-clicked, if any.
 641    /// This is set during a right-click mouse-down event and can be read by parent
 642    /// views to include a "Copy Link" item in their context menus.
 643    pub fn context_menu_link(&self) -> Option<&SharedString> {
 644        self.context_menu_link.as_ref()
 645    }
 646
 647    fn parse(&mut self, cx: &mut Context<Self>) {
 648        if self.source.is_empty() {
 649            self.should_reparse = false;
 650            self.pending_parse.take();
 651            self.parsed_markdown = ParsedMarkdown {
 652                source: self.source.clone(),
 653                ..Default::default()
 654            };
 655            self.active_root_block = None;
 656            self.images_by_source_offset.clear();
 657            self.mermaid_state.clear();
 658            cx.notify();
 659            cx.refresh_windows();
 660            return;
 661        }
 662
 663        if self.pending_parse.is_some() {
 664            self.should_reparse = true;
 665            return;
 666        }
 667        self.should_reparse = false;
 668        self.pending_parse = Some(self.start_background_parse(cx));
 669    }
 670
 671    fn start_background_parse(&self, cx: &Context<Self>) -> Task<()> {
 672        let source = self.source.clone();
 673        let should_parse_links_only = self.options.parse_links_only;
 674        let should_parse_html = self.options.parse_html;
 675        let should_render_mermaid_diagrams = self.options.render_mermaid_diagrams;
 676        let should_parse_heading_slugs = self.options.parse_heading_slugs;
 677        let language_registry = self.language_registry.clone();
 678        let fallback = self.fallback_code_block_language.clone();
 679
 680        let parsed = cx.background_spawn(async move {
 681            if should_parse_links_only {
 682                return (
 683                    ParsedMarkdown {
 684                        events: Arc::from(parse_links_only(source.as_ref())),
 685                        source,
 686                        languages_by_name: TreeMap::default(),
 687                        languages_by_path: TreeMap::default(),
 688                        root_block_starts: Arc::default(),
 689                        html_blocks: BTreeMap::default(),
 690                        mermaid_diagrams: BTreeMap::default(),
 691                        heading_slugs: HashMap::default(),
 692                        footnote_definitions: HashMap::default(),
 693                    },
 694                    Default::default(),
 695                );
 696            }
 697
 698            let parsed =
 699                parse_markdown_with_options(&source, should_parse_html, should_parse_heading_slugs);
 700            let events = parsed.events;
 701            let language_names = parsed.language_names;
 702            let paths = parsed.language_paths;
 703            let root_block_starts = parsed.root_block_starts;
 704            let html_blocks = parsed.html_blocks;
 705            let heading_slugs = parsed.heading_slugs;
 706            let footnote_definitions = parsed.footnote_definitions;
 707            let mermaid_diagrams = if should_render_mermaid_diagrams {
 708                extract_mermaid_diagrams(&source, &events)
 709            } else {
 710                BTreeMap::default()
 711            };
 712            let mut images_by_source_offset = HashMap::default();
 713            let mut languages_by_name = TreeMap::default();
 714            let mut languages_by_path = TreeMap::default();
 715            if let Some(registry) = language_registry.as_ref() {
 716                for name in language_names {
 717                    let language = if !name.is_empty() {
 718                        registry.language_for_name_or_extension(&name).left_future()
 719                    } else if let Some(fallback) = &fallback {
 720                        registry.language_for_name(fallback.as_ref()).right_future()
 721                    } else {
 722                        continue;
 723                    };
 724                    if let Ok(language) = language.await {
 725                        languages_by_name.insert(name, language);
 726                    }
 727                }
 728
 729                for path in paths {
 730                    if let Ok(language) = registry
 731                        .load_language_for_file_path(Path::new(path.as_ref()))
 732                        .await
 733                    {
 734                        languages_by_path.insert(path, language);
 735                    }
 736                }
 737            }
 738
 739            for (range, event) in &events {
 740                if let MarkdownEvent::Start(MarkdownTag::Image { dest_url, .. }) = event
 741                    && let Some(data_url) = dest_url.strip_prefix("data:")
 742                {
 743                    let Some((mime_info, data)) = data_url.split_once(',') else {
 744                        continue;
 745                    };
 746                    let Some((mime_type, encoding)) = mime_info.split_once(';') else {
 747                        continue;
 748                    };
 749                    let Some(format) = ImageFormat::from_mime_type(mime_type) else {
 750                        continue;
 751                    };
 752                    let is_base64 = encoding == "base64";
 753                    if is_base64
 754                        && let Some(bytes) = base64::prelude::BASE64_STANDARD
 755                            .decode(data)
 756                            .log_with_level(Level::Debug)
 757                    {
 758                        let image = Arc::new(Image::from_bytes(format, bytes));
 759                        images_by_source_offset.insert(range.start, image);
 760                    }
 761                }
 762            }
 763
 764            (
 765                ParsedMarkdown {
 766                    source,
 767                    events: Arc::from(events),
 768                    languages_by_name,
 769                    languages_by_path,
 770                    root_block_starts: Arc::from(root_block_starts),
 771                    html_blocks,
 772                    mermaid_diagrams,
 773                    heading_slugs,
 774                    footnote_definitions,
 775                },
 776                images_by_source_offset,
 777            )
 778        });
 779
 780        cx.spawn(async move |this, cx| {
 781            let (parsed, images_by_source_offset) = parsed.await;
 782
 783            this.update(cx, |this, cx| {
 784                this.parsed_markdown = parsed;
 785                this.images_by_source_offset = images_by_source_offset;
 786                if this.active_root_block.is_some_and(|block_index| {
 787                    block_index >= this.parsed_markdown.root_block_starts.len()
 788                }) {
 789                    this.active_root_block = None;
 790                }
 791                if this.options.render_mermaid_diagrams {
 792                    let parsed_markdown = this.parsed_markdown.clone();
 793                    this.mermaid_state.update(&parsed_markdown, cx);
 794                } else {
 795                    this.mermaid_state.clear();
 796                }
 797                this.pending_parse.take();
 798                if this.should_reparse {
 799                    this.parse(cx);
 800                }
 801                cx.notify();
 802                cx.refresh_windows();
 803            })
 804            .ok();
 805        })
 806    }
 807}
 808
 809impl Focusable for Markdown {
 810    fn focus_handle(&self, _cx: &App) -> FocusHandle {
 811        self.focus_handle.clone()
 812    }
 813}
 814
 815#[derive(Debug, Default, Clone)]
 816enum SelectMode {
 817    #[default]
 818    Character,
 819    Word(Range<usize>),
 820    Line(Range<usize>),
 821    All,
 822}
 823
 824#[derive(Clone, Default)]
 825struct Selection {
 826    start: usize,
 827    end: usize,
 828    reversed: bool,
 829    pending: bool,
 830    mode: SelectMode,
 831}
 832
 833impl Selection {
 834    fn set_head(&mut self, head: usize, rendered_text: &RenderedText) {
 835        match &self.mode {
 836            SelectMode::Character => {
 837                if head < self.tail() {
 838                    if !self.reversed {
 839                        self.end = self.start;
 840                        self.reversed = true;
 841                    }
 842                    self.start = head;
 843                } else {
 844                    if self.reversed {
 845                        self.start = self.end;
 846                        self.reversed = false;
 847                    }
 848                    self.end = head;
 849                }
 850            }
 851            SelectMode::Word(original_range) | SelectMode::Line(original_range) => {
 852                let head_range = if matches!(self.mode, SelectMode::Word(_)) {
 853                    rendered_text.surrounding_word_range(head)
 854                } else {
 855                    rendered_text.surrounding_line_range(head)
 856                };
 857
 858                if head < original_range.start {
 859                    self.start = head_range.start;
 860                    self.end = original_range.end;
 861                    self.reversed = true;
 862                } else if head >= original_range.end {
 863                    self.start = original_range.start;
 864                    self.end = head_range.end;
 865                    self.reversed = false;
 866                } else {
 867                    self.start = original_range.start;
 868                    self.end = original_range.end;
 869                    self.reversed = false;
 870                }
 871            }
 872            SelectMode::All => {
 873                self.start = 0;
 874                self.end = rendered_text
 875                    .lines
 876                    .last()
 877                    .map(|line| line.source_end)
 878                    .unwrap_or(0);
 879                self.reversed = false;
 880            }
 881        }
 882    }
 883
 884    fn tail(&self) -> usize {
 885        if self.reversed { self.end } else { self.start }
 886    }
 887}
 888
 889#[derive(Debug, Clone, Default)]
 890pub struct ParsedMarkdown {
 891    pub source: SharedString,
 892    pub events: Arc<[(Range<usize>, MarkdownEvent)]>,
 893    pub languages_by_name: TreeMap<SharedString, Arc<Language>>,
 894    pub languages_by_path: TreeMap<Arc<str>, Arc<Language>>,
 895    pub root_block_starts: Arc<[usize]>,
 896    pub(crate) html_blocks: BTreeMap<usize, html::html_parser::ParsedHtmlBlock>,
 897    pub(crate) mermaid_diagrams: BTreeMap<usize, ParsedMarkdownMermaidDiagram>,
 898    pub heading_slugs: HashMap<SharedString, usize>,
 899    pub footnote_definitions: HashMap<SharedString, usize>,
 900}
 901
 902impl ParsedMarkdown {
 903    pub fn source(&self) -> &SharedString {
 904        &self.source
 905    }
 906
 907    pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
 908        &self.events
 909    }
 910
 911    pub fn root_block_starts(&self) -> &Arc<[usize]> {
 912        &self.root_block_starts
 913    }
 914
 915    pub fn root_block_for_source_index(&self, source_index: usize) -> Option<usize> {
 916        if self.root_block_starts.is_empty() {
 917            return None;
 918        }
 919
 920        let partition = self
 921            .root_block_starts
 922            .partition_point(|block_start| *block_start <= source_index);
 923
 924        Some(partition.saturating_sub(1))
 925    }
 926}
 927
 928pub enum AutoscrollBehavior {
 929    /// Propagate the request up the element tree for the nearest
 930    /// scrollable ancestor (e.g. `List`) to handle.
 931    Propagate,
 932    /// Directly control a specific scroll handle.
 933    Controlled(ScrollHandle),
 934}
 935
 936pub struct MarkdownElement {
 937    markdown: Entity<Markdown>,
 938    style: MarkdownStyle,
 939    code_block_renderer: CodeBlockRenderer,
 940    on_url_click: Option<Box<dyn Fn(SharedString, &mut Window, &mut App)>>,
 941    on_source_click: Option<SourceClickCallback>,
 942    on_checkbox_toggle: Option<CheckboxToggleCallback>,
 943    image_resolver: Option<Box<dyn Fn(&str) -> Option<ImageSource>>>,
 944    show_root_block_markers: bool,
 945    autoscroll: AutoscrollBehavior,
 946}
 947
 948impl MarkdownElement {
 949    pub fn new(markdown: Entity<Markdown>, style: MarkdownStyle) -> Self {
 950        Self {
 951            markdown,
 952            style,
 953            code_block_renderer: CodeBlockRenderer::Default {
 954                copy_button_visibility: CopyButtonVisibility::VisibleOnHover,
 955                border: false,
 956            },
 957            on_url_click: None,
 958            on_source_click: None,
 959            on_checkbox_toggle: None,
 960            image_resolver: None,
 961            show_root_block_markers: false,
 962            autoscroll: AutoscrollBehavior::Propagate,
 963        }
 964    }
 965
 966    #[cfg(any(test, feature = "test-support"))]
 967    pub fn rendered_text(
 968        markdown: Entity<Markdown>,
 969        cx: &mut gpui::VisualTestContext,
 970        style: impl FnOnce(&Window, &App) -> MarkdownStyle,
 971    ) -> String {
 972        use gpui::size;
 973
 974        let (text, _) = cx.draw(
 975            Default::default(),
 976            size(px(600.0), px(600.0)),
 977            |window, cx| Self::new(markdown, style(window, cx)),
 978        );
 979        text.text
 980            .lines
 981            .iter()
 982            .map(|line| line.layout.wrapped_text())
 983            .collect::<Vec<_>>()
 984            .join("\n")
 985    }
 986
 987    pub fn code_block_renderer(mut self, variant: CodeBlockRenderer) -> Self {
 988        self.code_block_renderer = variant;
 989        self
 990    }
 991
 992    pub fn on_url_click(
 993        mut self,
 994        handler: impl Fn(SharedString, &mut Window, &mut App) + 'static,
 995    ) -> Self {
 996        self.on_url_click = Some(Box::new(handler));
 997        self
 998    }
 999
1000    pub fn on_source_click(
1001        mut self,
1002        handler: impl Fn(usize, usize, &mut Window, &mut App) -> bool + 'static,
1003    ) -> Self {
1004        self.on_source_click = Some(Box::new(handler));
1005        self
1006    }
1007
1008    pub fn on_checkbox_toggle(
1009        mut self,
1010        handler: impl Fn(Range<usize>, bool, &mut Window, &mut App) + 'static,
1011    ) -> Self {
1012        self.on_checkbox_toggle = Some(Rc::new(handler));
1013        self
1014    }
1015
1016    pub fn image_resolver(
1017        mut self,
1018        resolver: impl Fn(&str) -> Option<ImageSource> + 'static,
1019    ) -> Self {
1020        self.image_resolver = Some(Box::new(resolver));
1021        self
1022    }
1023
1024    pub fn show_root_block_markers(mut self) -> Self {
1025        self.show_root_block_markers = true;
1026        self
1027    }
1028
1029    pub fn scroll_handle(mut self, scroll_handle: ScrollHandle) -> Self {
1030        self.autoscroll = AutoscrollBehavior::Controlled(scroll_handle);
1031        self
1032    }
1033
1034    fn push_markdown_image(
1035        &self,
1036        builder: &mut MarkdownElementBuilder,
1037        range: &Range<usize>,
1038        source: ImageSource,
1039        width: Option<DefiniteLength>,
1040        height: Option<DefiniteLength>,
1041    ) {
1042        let align = builder.text_style().text_align;
1043        builder.modify_current_div(|el| {
1044            let mut image_container = el.flex().flex_row().items_center();
1045
1046            image_container = match align {
1047                TextAlign::Left => image_container.justify_start(),
1048                TextAlign::Center => image_container.justify_center(),
1049                TextAlign::Right => image_container.justify_end(),
1050            };
1051
1052            image_container.child(
1053                img(source)
1054                    .id(("markdown-image", range.start))
1055                    .max_w_full()
1056                    .when_some(height, |this, height| this.h(height))
1057                    .when_some(width, |this, width| this.w(width)),
1058            )
1059        });
1060    }
1061
1062    fn push_markdown_paragraph(
1063        &self,
1064        builder: &mut MarkdownElementBuilder,
1065        range: &Range<usize>,
1066        markdown_end: usize,
1067        text_align_override: Option<TextAlign>,
1068    ) {
1069        let align = text_align_override.unwrap_or(self.style.base_text_style.text_align);
1070        let mut paragraph = div().when(!self.style.height_is_multiple_of_line_height, |el| {
1071            el.mb_2().line_height(rems(1.3))
1072        });
1073
1074        paragraph = match align {
1075            TextAlign::Center => paragraph.text_center(),
1076            TextAlign::Left => paragraph.text_left(),
1077            TextAlign::Right => paragraph.text_right(),
1078        };
1079
1080        builder.push_text_style(TextStyleRefinement {
1081            text_align: Some(align),
1082            ..Default::default()
1083        });
1084        builder.push_div(paragraph, range, markdown_end);
1085    }
1086
1087    fn pop_markdown_paragraph(&self, builder: &mut MarkdownElementBuilder) {
1088        builder.pop_div();
1089        builder.pop_text_style();
1090    }
1091
1092    fn push_markdown_heading(
1093        &self,
1094        builder: &mut MarkdownElementBuilder,
1095        level: pulldown_cmark::HeadingLevel,
1096        range: &Range<usize>,
1097        markdown_end: usize,
1098        text_align_override: Option<TextAlign>,
1099    ) {
1100        let align = text_align_override.unwrap_or(self.style.base_text_style.text_align);
1101        let mut heading = div().mt_4().mb_2();
1102        heading = apply_heading_style(heading, level, self.style.heading_level_styles.as_ref());
1103
1104        heading = match align {
1105            TextAlign::Center => heading.text_center(),
1106            TextAlign::Left => heading.text_left(),
1107            TextAlign::Right => heading.text_right(),
1108        };
1109
1110        let mut heading_style = self.style.heading.clone();
1111        let heading_text_style = heading_style.text_style().clone();
1112        heading.style().refine(&heading_style);
1113
1114        builder.push_text_style(TextStyleRefinement {
1115            text_align: Some(align),
1116            ..heading_text_style
1117        });
1118        builder.push_div(heading, range, markdown_end);
1119    }
1120
1121    fn pop_markdown_heading(&self, builder: &mut MarkdownElementBuilder) {
1122        builder.pop_div();
1123        builder.pop_text_style();
1124    }
1125
1126    fn push_markdown_block_quote(
1127        &self,
1128        builder: &mut MarkdownElementBuilder,
1129        range: &Range<usize>,
1130        markdown_end: usize,
1131    ) {
1132        builder.push_text_style(self.style.block_quote.clone());
1133        builder.push_div(
1134            div()
1135                .pl_4()
1136                .mb_2()
1137                .border_l_4()
1138                .border_color(self.style.block_quote_border_color),
1139            range,
1140            markdown_end,
1141        );
1142    }
1143
1144    fn pop_markdown_block_quote(&self, builder: &mut MarkdownElementBuilder) {
1145        builder.pop_div();
1146        builder.pop_text_style();
1147    }
1148
1149    fn push_markdown_list_item(
1150        &self,
1151        builder: &mut MarkdownElementBuilder,
1152        bullet: AnyElement,
1153        range: &Range<usize>,
1154        markdown_end: usize,
1155    ) {
1156        builder.push_div(
1157            div()
1158                .when(!self.style.height_is_multiple_of_line_height, |el| {
1159                    el.mb_1().gap_1().line_height(rems(1.3))
1160                })
1161                .h_flex()
1162                .items_start()
1163                .child(bullet),
1164            range,
1165            markdown_end,
1166        );
1167        // Without `w_0`, text doesn't wrap to the width of the container.
1168        builder.push_div(div().flex_1().w_0(), range, markdown_end);
1169    }
1170
1171    fn pop_markdown_list_item(&self, builder: &mut MarkdownElementBuilder) {
1172        builder.pop_div();
1173        builder.pop_div();
1174    }
1175
1176    fn paint_highlight_range(
1177        bounds: Bounds<Pixels>,
1178        start: usize,
1179        end: usize,
1180        color: Hsla,
1181        rendered_text: &RenderedText,
1182        window: &mut Window,
1183    ) {
1184        let start_pos = rendered_text.position_for_source_index(start);
1185        let end_pos = rendered_text.position_for_source_index(end);
1186        if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
1187            start_pos.zip(end_pos)
1188        {
1189            if start_position.y == end_position.y {
1190                window.paint_quad(quad(
1191                    Bounds::from_corners(
1192                        start_position,
1193                        point(end_position.x, end_position.y + end_line_height),
1194                    ),
1195                    Pixels::ZERO,
1196                    color,
1197                    Edges::default(),
1198                    Hsla::transparent_black(),
1199                    BorderStyle::default(),
1200                ));
1201            } else {
1202                window.paint_quad(quad(
1203                    Bounds::from_corners(
1204                        start_position,
1205                        point(bounds.right(), start_position.y + start_line_height),
1206                    ),
1207                    Pixels::ZERO,
1208                    color,
1209                    Edges::default(),
1210                    Hsla::transparent_black(),
1211                    BorderStyle::default(),
1212                ));
1213
1214                if end_position.y > start_position.y + start_line_height {
1215                    window.paint_quad(quad(
1216                        Bounds::from_corners(
1217                            point(bounds.left(), start_position.y + start_line_height),
1218                            point(bounds.right(), end_position.y),
1219                        ),
1220                        Pixels::ZERO,
1221                        color,
1222                        Edges::default(),
1223                        Hsla::transparent_black(),
1224                        BorderStyle::default(),
1225                    ));
1226                }
1227
1228                window.paint_quad(quad(
1229                    Bounds::from_corners(
1230                        point(bounds.left(), end_position.y),
1231                        point(end_position.x, end_position.y + end_line_height),
1232                    ),
1233                    Pixels::ZERO,
1234                    color,
1235                    Edges::default(),
1236                    Hsla::transparent_black(),
1237                    BorderStyle::default(),
1238                ));
1239            }
1240        }
1241    }
1242
1243    fn paint_selection(
1244        &self,
1245        bounds: Bounds<Pixels>,
1246        rendered_text: &RenderedText,
1247        window: &mut Window,
1248        cx: &mut App,
1249    ) {
1250        let selection = self.markdown.read(cx).selection.clone();
1251        Self::paint_highlight_range(
1252            bounds,
1253            selection.start,
1254            selection.end,
1255            self.style.selection_background_color,
1256            rendered_text,
1257            window,
1258        );
1259    }
1260
1261    fn paint_search_highlights(
1262        &self,
1263        bounds: Bounds<Pixels>,
1264        rendered_text: &RenderedText,
1265        window: &mut Window,
1266        cx: &mut App,
1267    ) {
1268        let markdown = self.markdown.read(cx);
1269        let active_index = markdown.active_search_highlight;
1270        let colors = cx.theme().colors();
1271
1272        for (i, highlight_range) in markdown.search_highlights.iter().enumerate() {
1273            let color = if Some(i) == active_index {
1274                colors.search_active_match_background
1275            } else {
1276                colors.search_match_background
1277            };
1278            Self::paint_highlight_range(
1279                bounds,
1280                highlight_range.start,
1281                highlight_range.end,
1282                color,
1283                rendered_text,
1284                window,
1285            );
1286        }
1287    }
1288
1289    fn paint_mouse_listeners(
1290        &mut self,
1291        hitbox: &Hitbox,
1292        rendered_text: &RenderedText,
1293        window: &mut Window,
1294        cx: &mut App,
1295    ) {
1296        if self.style.prevent_mouse_interaction {
1297            return;
1298        }
1299
1300        let is_hovering_clickable = hitbox.is_hovered(window)
1301            && !self.markdown.read(cx).selection.pending
1302            && rendered_text
1303                .source_index_for_position(window.mouse_position())
1304                .ok()
1305                .is_some_and(|source_index| {
1306                    rendered_text.link_for_source_index(source_index).is_some()
1307                        || rendered_text
1308                            .footnote_ref_for_source_index(source_index)
1309                            .is_some()
1310                });
1311
1312        if is_hovering_clickable {
1313            window.set_cursor_style(CursorStyle::PointingHand, hitbox);
1314        } else {
1315            window.set_cursor_style(CursorStyle::IBeam, hitbox);
1316        }
1317
1318        let on_open_url = self.on_url_click.take();
1319        let on_source_click = self.on_source_click.take();
1320
1321        self.on_mouse_event(window, cx, {
1322            let hitbox = hitbox.clone();
1323            let rendered_text = rendered_text.clone();
1324            move |markdown, event: &MouseDownEvent, phase, window, _cx| {
1325                if phase.capture()
1326                    && event.button == MouseButton::Right
1327                    && hitbox.is_hovered(window)
1328                {
1329                    let link = rendered_text
1330                        .source_index_for_position(event.position)
1331                        .ok()
1332                        .and_then(|ix| rendered_text.link_for_source_index(ix))
1333                        .map(|link| link.destination_url.clone());
1334                    markdown.capture_for_context_menu(link);
1335                }
1336            }
1337        });
1338
1339        self.on_mouse_event(window, cx, {
1340            let rendered_text = rendered_text.clone();
1341            let hitbox = hitbox.clone();
1342            move |markdown, event: &MouseDownEvent, phase, window, cx| {
1343                if hitbox.is_hovered(window) {
1344                    if phase.bubble() && event.button != MouseButton::Right {
1345                        let position_result =
1346                            rendered_text.source_index_for_position(event.position);
1347
1348                        if let Ok(source_index) = position_result {
1349                            if let Some(footnote_ref) =
1350                                rendered_text.footnote_ref_for_source_index(source_index)
1351                            {
1352                                markdown.pressed_footnote_ref = Some(footnote_ref.clone());
1353                            } else if let Some(link) =
1354                                rendered_text.link_for_source_index(source_index)
1355                            {
1356                                markdown.pressed_link = Some(link.clone());
1357                            }
1358                        }
1359
1360                        if markdown.pressed_footnote_ref.is_none()
1361                            && markdown.pressed_link.is_none()
1362                        {
1363                            let source_index = match position_result {
1364                                Ok(ix) | Err(ix) => ix,
1365                            };
1366                            if let Some(handler) = on_source_click.as_ref() {
1367                                let blocked = handler(source_index, event.click_count, window, cx);
1368                                if blocked {
1369                                    markdown.selection = Selection::default();
1370                                    markdown.pressed_link = None;
1371                                    window.prevent_default();
1372                                    cx.notify();
1373                                    return;
1374                                }
1375                            }
1376                            let (range, mode) = match event.click_count {
1377                                1 => {
1378                                    let range = source_index..source_index;
1379                                    (range, SelectMode::Character)
1380                                }
1381                                2 => {
1382                                    let range = rendered_text.surrounding_word_range(source_index);
1383                                    (range.clone(), SelectMode::Word(range))
1384                                }
1385                                3 => {
1386                                    let range = rendered_text.surrounding_line_range(source_index);
1387                                    (range.clone(), SelectMode::Line(range))
1388                                }
1389                                _ => {
1390                                    let range = 0..rendered_text
1391                                        .lines
1392                                        .last()
1393                                        .map(|line| line.source_end)
1394                                        .unwrap_or(0);
1395                                    (range, SelectMode::All)
1396                                }
1397                            };
1398                            markdown.selection = Selection {
1399                                start: range.start,
1400                                end: range.end,
1401                                reversed: false,
1402                                pending: true,
1403                                mode,
1404                            };
1405                            window.focus(&markdown.focus_handle, cx);
1406                        }
1407
1408                        window.prevent_default();
1409                        cx.notify();
1410                    }
1411                } else if phase.capture() && event.button == MouseButton::Left {
1412                    markdown.selection = Selection::default();
1413                    markdown.pressed_link = None;
1414                    cx.notify();
1415                }
1416            }
1417        });
1418        self.on_mouse_event(window, cx, {
1419            let rendered_text = rendered_text.clone();
1420            let hitbox = hitbox.clone();
1421            let was_hovering_clickable = is_hovering_clickable;
1422            move |markdown, event: &MouseMoveEvent, phase, window, cx| {
1423                if phase.capture() {
1424                    return;
1425                }
1426
1427                if markdown.selection.pending {
1428                    let source_index = match rendered_text.source_index_for_position(event.position)
1429                    {
1430                        Ok(ix) | Err(ix) => ix,
1431                    };
1432                    markdown.selection.set_head(source_index, &rendered_text);
1433                    markdown.autoscroll_code_block(source_index, event.position);
1434                    markdown.autoscroll_request = Some(source_index);
1435                    cx.notify();
1436                } else {
1437                    let is_hovering_clickable = hitbox.is_hovered(window)
1438                        && rendered_text
1439                            .source_index_for_position(event.position)
1440                            .ok()
1441                            .is_some_and(|source_index| {
1442                                rendered_text.link_for_source_index(source_index).is_some()
1443                                    || rendered_text
1444                                        .footnote_ref_for_source_index(source_index)
1445                                        .is_some()
1446                            });
1447                    if is_hovering_clickable != was_hovering_clickable {
1448                        cx.notify();
1449                    }
1450                }
1451            }
1452        });
1453        self.on_mouse_event(window, cx, {
1454            let rendered_text = rendered_text.clone();
1455            move |markdown, event: &MouseUpEvent, phase, window, cx| {
1456                if phase.bubble() {
1457                    let source_index = rendered_text.source_index_for_position(event.position).ok();
1458                    if let Some(pressed_footnote_ref) = markdown.pressed_footnote_ref.take()
1459                        && source_index
1460                            .and_then(|ix| rendered_text.footnote_ref_for_source_index(ix))
1461                            == Some(&pressed_footnote_ref)
1462                    {
1463                        if let Some(source_index) =
1464                            markdown.footnote_definition_content_start(&pressed_footnote_ref.label)
1465                        {
1466                            markdown.autoscroll_request = Some(source_index);
1467                            cx.notify();
1468                        }
1469                    } else if let Some(pressed_link) = markdown.pressed_link.take()
1470                        && source_index.and_then(|ix| rendered_text.link_for_source_index(ix))
1471                            == Some(&pressed_link)
1472                    {
1473                        if let Some(open_url) = on_open_url.as_ref() {
1474                            open_url(pressed_link.destination_url, window, cx);
1475                        } else {
1476                            cx.open_url(&pressed_link.destination_url);
1477                        }
1478                    }
1479                } else if markdown.selection.pending {
1480                    markdown.selection.pending = false;
1481                    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
1482                    {
1483                        let text = rendered_text
1484                            .text_for_range(markdown.selection.start..markdown.selection.end);
1485                        cx.write_to_primary(ClipboardItem::new_string(text))
1486                    }
1487                    cx.notify();
1488                }
1489            }
1490        });
1491    }
1492
1493    fn autoscroll(
1494        &self,
1495        rendered_text: &RenderedText,
1496        window: &mut Window,
1497        cx: &mut App,
1498    ) -> Option<()> {
1499        let autoscroll_index = self
1500            .markdown
1501            .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
1502        let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
1503
1504        match &self.autoscroll {
1505            AutoscrollBehavior::Controlled(scroll_handle) => {
1506                let viewport = scroll_handle.bounds();
1507                let margin = line_height * 3.;
1508                let top_goal = viewport.top() + margin;
1509                let bottom_goal = viewport.bottom() - margin;
1510                let current_offset = scroll_handle.offset();
1511
1512                let new_offset_y = if position.y < top_goal {
1513                    current_offset.y + (top_goal - position.y)
1514                } else if position.y + line_height > bottom_goal {
1515                    current_offset.y + (bottom_goal - (position.y + line_height))
1516                } else {
1517                    current_offset.y
1518                };
1519
1520                scroll_handle.set_offset(point(
1521                    current_offset.x,
1522                    new_offset_y.clamp(-scroll_handle.max_offset().y, Pixels::ZERO),
1523                ));
1524            }
1525            AutoscrollBehavior::Propagate => {
1526                let text_style = self.style.base_text_style.clone();
1527                let font_id = window.text_system().resolve_font(&text_style.font());
1528                let font_size = text_style.font_size.to_pixels(window.rem_size());
1529                let em_width = window.text_system().em_width(font_id, font_size).unwrap();
1530                window.request_autoscroll(Bounds::from_corners(
1531                    point(position.x - 3. * em_width, position.y - 3. * line_height),
1532                    point(position.x + 3. * em_width, position.y + 3. * line_height),
1533                ));
1534            }
1535        }
1536        Some(())
1537    }
1538
1539    fn on_mouse_event<T: MouseEvent>(
1540        &self,
1541        window: &mut Window,
1542        _cx: &mut App,
1543        mut f: impl 'static
1544        + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
1545    ) {
1546        window.on_mouse_event({
1547            let markdown = self.markdown.downgrade();
1548            move |event, phase, window, cx| {
1549                markdown
1550                    .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
1551                    .log_err();
1552            }
1553        });
1554    }
1555}
1556
1557impl Styled for MarkdownElement {
1558    fn style(&mut self) -> &mut StyleRefinement {
1559        &mut self.style.container_style
1560    }
1561}
1562
1563impl Element for MarkdownElement {
1564    type RequestLayoutState = RenderedMarkdown;
1565    type PrepaintState = Hitbox;
1566
1567    fn id(&self) -> Option<ElementId> {
1568        None
1569    }
1570
1571    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
1572        None
1573    }
1574
1575    fn request_layout(
1576        &mut self,
1577        _id: Option<&GlobalElementId>,
1578        _inspector_id: Option<&gpui::InspectorElementId>,
1579        window: &mut Window,
1580        cx: &mut App,
1581    ) -> (gpui::LayoutId, Self::RequestLayoutState) {
1582        let mut builder = MarkdownElementBuilder::new(
1583            &self.style.container_style,
1584            self.style.base_text_style.clone(),
1585            self.style.syntax.clone(),
1586        );
1587        let (parsed_markdown, images, active_root_block, render_mermaid_diagrams, mermaid_state) = {
1588            let markdown = self.markdown.read(cx);
1589            (
1590                markdown.parsed_markdown.clone(),
1591                markdown.images_by_source_offset.clone(),
1592                markdown.active_root_block,
1593                markdown.options.render_mermaid_diagrams,
1594                markdown.mermaid_state.clone(),
1595            )
1596        };
1597        let markdown_end = if let Some(last) = parsed_markdown.events.last() {
1598            last.0.end
1599        } else {
1600            0
1601        };
1602        let mut code_block_ids = HashSet::default();
1603
1604        let mut current_img_block_range: Option<Range<usize>> = None;
1605        let mut handled_html_block = false;
1606        let mut rendered_mermaid_block = false;
1607        for (index, (range, event)) in parsed_markdown.events.iter().enumerate() {
1608            // Skip alt text for images that rendered
1609            if let Some(current_img_block_range) = &current_img_block_range
1610                && current_img_block_range.end > range.end
1611            {
1612                continue;
1613            }
1614
1615            if handled_html_block {
1616                if let MarkdownEvent::End(MarkdownTagEnd::HtmlBlock) = event {
1617                    handled_html_block = false;
1618                } else {
1619                    continue;
1620                }
1621            }
1622
1623            if rendered_mermaid_block {
1624                if matches!(event, MarkdownEvent::End(MarkdownTagEnd::CodeBlock)) {
1625                    rendered_mermaid_block = false;
1626                }
1627                continue;
1628            }
1629
1630            match event {
1631                MarkdownEvent::RootStart => {
1632                    if self.show_root_block_markers {
1633                        builder.push_root_block(range, markdown_end);
1634                    }
1635                }
1636                MarkdownEvent::RootEnd(root_block_index) => {
1637                    if self.show_root_block_markers {
1638                        builder.pop_root_block(
1639                            active_root_block == Some(*root_block_index),
1640                            cx.theme().colors().border,
1641                            cx.theme().colors().border_variant,
1642                        );
1643                    }
1644                }
1645                MarkdownEvent::Start(tag) => {
1646                    match tag {
1647                        MarkdownTag::Image { dest_url, .. } => {
1648                            if let Some(image) = images.get(&range.start) {
1649                                current_img_block_range = Some(range.clone());
1650                                self.push_markdown_image(
1651                                    &mut builder,
1652                                    range,
1653                                    image.clone().into(),
1654                                    None,
1655                                    None,
1656                                );
1657                            } else if let Some(source) = self
1658                                .image_resolver
1659                                .as_ref()
1660                                .and_then(|resolve| resolve(dest_url.as_ref()))
1661                            {
1662                                current_img_block_range = Some(range.clone());
1663                                self.push_markdown_image(&mut builder, range, source, None, None);
1664                            }
1665                        }
1666                        MarkdownTag::Paragraph => {
1667                            self.push_markdown_paragraph(&mut builder, range, markdown_end, None);
1668                        }
1669                        MarkdownTag::Heading { level, .. } => {
1670                            self.push_markdown_heading(
1671                                &mut builder,
1672                                *level,
1673                                range,
1674                                markdown_end,
1675                                None,
1676                            );
1677                        }
1678                        MarkdownTag::BlockQuote => {
1679                            self.push_markdown_block_quote(&mut builder, range, markdown_end);
1680                        }
1681                        MarkdownTag::CodeBlock { kind, .. } => {
1682                            if render_mermaid_diagrams
1683                                && let Some(mermaid_diagram) =
1684                                    parsed_markdown.mermaid_diagrams.get(&range.start)
1685                            {
1686                                builder.push_sourced_element(
1687                                    mermaid_diagram.content_range.clone(),
1688                                    render_mermaid_diagram(
1689                                        mermaid_diagram,
1690                                        &mermaid_state,
1691                                        &self.style,
1692                                    ),
1693                                );
1694                                rendered_mermaid_block = true;
1695                                continue;
1696                            }
1697
1698                            let language = match kind {
1699                                CodeBlockKind::Fenced => None,
1700                                CodeBlockKind::FencedLang(language) => {
1701                                    parsed_markdown.languages_by_name.get(language).cloned()
1702                                }
1703                                CodeBlockKind::FencedSrc(path_range) => parsed_markdown
1704                                    .languages_by_path
1705                                    .get(&path_range.path)
1706                                    .cloned(),
1707                                _ => None,
1708                            };
1709
1710                            let is_indented = matches!(kind, CodeBlockKind::Indented);
1711                            let scroll_handle = if self.style.code_block_overflow_x_scroll {
1712                                code_block_ids.insert(range.start);
1713                                Some(self.markdown.update(cx, |markdown, _| {
1714                                    markdown.code_block_scroll_handle(range.start)
1715                                }))
1716                            } else {
1717                                None
1718                            };
1719
1720                            match (&self.code_block_renderer, is_indented) {
1721                                (CodeBlockRenderer::Default { .. }, _) | (_, true) => {
1722                                    // This is a parent container that we can position the copy button inside.
1723                                    let parent_container =
1724                                        div().group("code_block").relative().w_full();
1725
1726                                    let mut parent_container: AnyDiv = if let Some(scroll_handle) =
1727                                        scroll_handle.as_ref()
1728                                    {
1729                                        let scrollbars = Scrollbars::new(ScrollAxes::Horizontal)
1730                                            .id(("markdown-code-block-scrollbar", range.start))
1731                                            .tracked_scroll_handle(scroll_handle)
1732                                            .with_track_along(
1733                                                ScrollAxes::Horizontal,
1734                                                cx.theme().colors().editor_background,
1735                                            )
1736                                            .notify_content();
1737
1738                                        parent_container
1739                                            .rounded_lg()
1740                                            .custom_scrollbars(scrollbars, window, cx)
1741                                            .into()
1742                                    } else {
1743                                        parent_container.into()
1744                                    };
1745
1746                                    if let CodeBlockRenderer::Default { border: true, .. } =
1747                                        &self.code_block_renderer
1748                                    {
1749                                        parent_container = parent_container
1750                                            .rounded_md()
1751                                            .border_1()
1752                                            .border_color(cx.theme().colors().border_variant);
1753                                    }
1754
1755                                    parent_container.style().refine(&self.style.code_block);
1756                                    builder.push_div(parent_container, range, markdown_end);
1757
1758                                    let code_block = div()
1759                                        .id(("code-block", range.start))
1760                                        .rounded_lg()
1761                                        .map(|mut code_block| {
1762                                            if let Some(scroll_handle) = scroll_handle.as_ref() {
1763                                                code_block.style().restrict_scroll_to_axis =
1764                                                    Some(true);
1765                                                code_block
1766                                                    .flex()
1767                                                    .overflow_x_scroll()
1768                                                    .track_scroll(scroll_handle)
1769                                            } else {
1770                                                code_block.w_full()
1771                                            }
1772                                        });
1773
1774                                    builder.push_text_style(self.style.code_block.text.to_owned());
1775                                    builder.push_code_block(language);
1776                                    builder.push_div(code_block, range, markdown_end);
1777                                }
1778                                (CodeBlockRenderer::Custom { .. }, _) => {}
1779                            }
1780                        }
1781                        MarkdownTag::HtmlBlock => {
1782                            builder.push_div(div(), range, markdown_end);
1783                            if let Some(block) = parsed_markdown.html_blocks.get(&range.start) {
1784                                self.render_html_block(block, &mut builder, markdown_end, cx);
1785                                handled_html_block = true;
1786                            }
1787                        }
1788                        MarkdownTag::List(bullet_index) => {
1789                            builder.push_list(*bullet_index);
1790                            builder.push_div(div().pl_2p5(), range, markdown_end);
1791                        }
1792                        MarkdownTag::Item => {
1793                            let bullet =
1794                                if let Some((task_range, MarkdownEvent::TaskListMarker(checked))) =
1795                                    parsed_markdown.events.get(index.saturating_add(1))
1796                                {
1797                                    let source = &parsed_markdown.source()[range.clone()];
1798                                    let checked = *checked;
1799                                    let toggle_state = if checked {
1800                                        ToggleState::Selected
1801                                    } else {
1802                                        ToggleState::Unselected
1803                                    };
1804
1805                                    let checkbox = Checkbox::new(
1806                                        ElementId::Name(source.to_string().into()),
1807                                        toggle_state,
1808                                    )
1809                                    .fill();
1810
1811                                    if let Some(on_toggle) = self.on_checkbox_toggle.clone() {
1812                                        let task_source_range = task_range.clone();
1813                                        checkbox
1814                                            .on_click(move |_state, window, cx| {
1815                                                on_toggle(
1816                                                    task_source_range.clone(),
1817                                                    !checked,
1818                                                    window,
1819                                                    cx,
1820                                                );
1821                                            })
1822                                            .into_any_element()
1823                                    } else {
1824                                        checkbox.visualization_only(true).into_any_element()
1825                                    }
1826                                } else if let Some(bullet_index) = builder.next_bullet_index() {
1827                                    div().child(format!("{}.", bullet_index)).into_any_element()
1828                                } else {
1829                                    div().child("").into_any_element()
1830                                };
1831                            self.push_markdown_list_item(&mut builder, bullet, range, markdown_end);
1832                        }
1833                        MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
1834                            font_style: Some(FontStyle::Italic),
1835                            ..Default::default()
1836                        }),
1837                        MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
1838                            font_weight: Some(FontWeight::BOLD),
1839                            ..Default::default()
1840                        }),
1841                        MarkdownTag::Strikethrough => {
1842                            builder.push_text_style(TextStyleRefinement {
1843                                strikethrough: Some(StrikethroughStyle {
1844                                    thickness: px(1.),
1845                                    color: None,
1846                                }),
1847                                ..Default::default()
1848                            })
1849                        }
1850                        MarkdownTag::Link { dest_url, .. } => {
1851                            if builder.code_block_stack.is_empty() {
1852                                builder.push_link(dest_url.clone(), range.clone());
1853                                let style = self
1854                                    .style
1855                                    .link_callback
1856                                    .as_ref()
1857                                    .and_then(|callback| callback(dest_url, cx))
1858                                    .unwrap_or_else(|| self.style.link.clone());
1859                                builder.push_text_style(style)
1860                            }
1861                        }
1862                        MarkdownTag::FootnoteDefinition(label) => {
1863                            if !builder.rendered_footnote_separator {
1864                                builder.rendered_footnote_separator = true;
1865                                builder.push_div(
1866                                    div()
1867                                        .border_t_1()
1868                                        .mt_2()
1869                                        .border_color(self.style.rule_color),
1870                                    range,
1871                                    markdown_end,
1872                                );
1873                                builder.pop_div();
1874                            }
1875                            builder.push_div(
1876                                div()
1877                                    .pt_1()
1878                                    .mb_1()
1879                                    .line_height(rems(1.3))
1880                                    .text_size(rems(0.85))
1881                                    .h_flex()
1882                                    .items_start()
1883                                    .gap_2()
1884                                    .child(
1885                                        div().text_size(rems(0.85)).child(format!("{}.", label)),
1886                                    ),
1887                                range,
1888                                markdown_end,
1889                            );
1890                            builder.push_div(div().flex_1().w_0(), range, markdown_end);
1891                        }
1892                        MarkdownTag::MetadataBlock(_) => {}
1893                        MarkdownTag::Table(alignments) => {
1894                            builder.table.start(alignments.clone());
1895
1896                            let column_count = alignments.len();
1897                            builder.push_div(
1898                                div()
1899                                    .id(("table", range.start))
1900                                    .grid()
1901                                    .grid_cols(column_count as u16)
1902                                    .when(self.style.table_columns_min_size, |this| {
1903                                        this.grid_cols_min_content(column_count as u16)
1904                                    })
1905                                    .when(!self.style.table_columns_min_size, |this| {
1906                                        this.grid_cols(column_count as u16)
1907                                    })
1908                                    .w_full()
1909                                    .mb_2()
1910                                    .border(px(1.5))
1911                                    .border_color(cx.theme().colors().border)
1912                                    .rounded_sm()
1913                                    .overflow_hidden(),
1914                                range,
1915                                markdown_end,
1916                            );
1917                        }
1918                        MarkdownTag::TableHead => {
1919                            builder.table.start_head();
1920                            builder.push_text_style(TextStyleRefinement {
1921                                font_weight: Some(FontWeight::SEMIBOLD),
1922                                ..Default::default()
1923                            });
1924                        }
1925                        MarkdownTag::TableRow => {
1926                            builder.table.start_row();
1927                        }
1928                        MarkdownTag::TableCell => {
1929                            let is_header = builder.table.in_head;
1930                            let row_index = builder.table.row_index;
1931                            let col_index = builder.table.col_index;
1932
1933                            builder.push_div(
1934                                div()
1935                                    .when(col_index > 0, |this| this.border_l_1())
1936                                    .when(row_index > 0, |this| this.border_t_1())
1937                                    .border_color(cx.theme().colors().border)
1938                                    .px_1()
1939                                    .py_0p5()
1940                                    .when(is_header, |this| {
1941                                        this.bg(cx.theme().colors().title_bar_background)
1942                                    })
1943                                    .when(!is_header && row_index % 2 == 1, |this| {
1944                                        this.bg(cx.theme().colors().panel_background)
1945                                    }),
1946                                range,
1947                                markdown_end,
1948                            );
1949                        }
1950                        _ => log::debug!("unsupported markdown tag {:?}", tag),
1951                    }
1952                }
1953                MarkdownEvent::End(tag) => match tag {
1954                    MarkdownTagEnd::Image => {
1955                        current_img_block_range.take();
1956                    }
1957                    MarkdownTagEnd::Paragraph => {
1958                        self.pop_markdown_paragraph(&mut builder);
1959                    }
1960                    MarkdownTagEnd::Heading(_) => {
1961                        self.pop_markdown_heading(&mut builder);
1962                    }
1963                    MarkdownTagEnd::BlockQuote(_kind) => {
1964                        self.pop_markdown_block_quote(&mut builder);
1965                    }
1966                    MarkdownTagEnd::CodeBlock => {
1967                        builder.trim_trailing_newline();
1968
1969                        builder.pop_div();
1970                        builder.pop_code_block();
1971                        builder.pop_text_style();
1972
1973                        if let CodeBlockRenderer::Default {
1974                            copy_button_visibility,
1975                            ..
1976                        } = &self.code_block_renderer
1977                            && *copy_button_visibility != CopyButtonVisibility::Hidden
1978                        {
1979                            builder.modify_current_div(|el| {
1980                                let content_range = parser::extract_code_block_content_range(
1981                                    &parsed_markdown.source()[range.clone()],
1982                                );
1983                                let content_range = content_range.start + range.start
1984                                    ..content_range.end + range.start;
1985
1986                                let code = parsed_markdown.source()[content_range].to_string();
1987                                let codeblock = render_copy_code_block_button(
1988                                    range.end,
1989                                    code,
1990                                    self.markdown.clone(),
1991                                );
1992                                el.child(
1993                                    h_flex()
1994                                        .w_4()
1995                                        .absolute()
1996                                        .justify_end()
1997                                        .when_else(
1998                                            *copy_button_visibility
1999                                                == CopyButtonVisibility::VisibleOnHover,
2000                                            |this| {
2001                                                this.top_0()
2002                                                    .right_0()
2003                                                    .visible_on_hover("code_block")
2004                                            },
2005                                            |this| this.top_1p5().right_1p5(),
2006                                        )
2007                                        .child(codeblock),
2008                                )
2009                            });
2010                        }
2011
2012                        // Pop the parent container.
2013                        builder.pop_div();
2014                    }
2015                    MarkdownTagEnd::HtmlBlock => builder.pop_div(),
2016                    MarkdownTagEnd::List(_) => {
2017                        builder.pop_list();
2018                        builder.pop_div();
2019                    }
2020                    MarkdownTagEnd::Item => {
2021                        self.pop_markdown_list_item(&mut builder);
2022                    }
2023                    MarkdownTagEnd::Emphasis => builder.pop_text_style(),
2024                    MarkdownTagEnd::Strong => builder.pop_text_style(),
2025                    MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
2026                    MarkdownTagEnd::Link => {
2027                        if builder.code_block_stack.is_empty() {
2028                            builder.pop_text_style()
2029                        }
2030                    }
2031                    MarkdownTagEnd::Table => {
2032                        builder.pop_div();
2033                        builder.table.end();
2034                    }
2035                    MarkdownTagEnd::TableHead => {
2036                        builder.pop_text_style();
2037                        builder.table.end_head();
2038                    }
2039                    MarkdownTagEnd::TableRow => {
2040                        builder.table.end_row();
2041                    }
2042                    MarkdownTagEnd::TableCell => {
2043                        builder.replace_pending_checkbox(range);
2044                        builder.pop_div();
2045                        builder.table.end_cell();
2046                    }
2047                    MarkdownTagEnd::FootnoteDefinition => {
2048                        builder.pop_div();
2049                        builder.pop_div();
2050                    }
2051                    _ => log::debug!("unsupported markdown tag end: {:?}", tag),
2052                },
2053                MarkdownEvent::Text => {
2054                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2055                }
2056                MarkdownEvent::SubstitutedText(text) => {
2057                    builder.push_text(text, range.clone());
2058                }
2059                MarkdownEvent::Code => {
2060                    builder.push_text_style(self.style.inline_code.clone());
2061                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2062                    builder.pop_text_style();
2063                }
2064                MarkdownEvent::Html => {
2065                    let html = &parsed_markdown.source[range.clone()];
2066                    if html.starts_with("<!--") {
2067                        builder.html_comment = true;
2068                    }
2069                    if html.trim_end().ends_with("-->") {
2070                        builder.html_comment = false;
2071                        continue;
2072                    }
2073                    if builder.html_comment {
2074                        continue;
2075                    }
2076                    builder.push_text(html, range.clone());
2077                }
2078                MarkdownEvent::InlineHtml => {
2079                    let html = &parsed_markdown.source[range.clone()];
2080                    if html.starts_with("<code>") {
2081                        builder.push_text_style(self.style.inline_code.clone());
2082                        continue;
2083                    }
2084                    if html.trim_end().starts_with("</code>") {
2085                        builder.pop_text_style();
2086                        continue;
2087                    }
2088                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
2089                }
2090                MarkdownEvent::Rule => {
2091                    builder.push_div(
2092                        div()
2093                            .border_b_1()
2094                            .my_2()
2095                            .border_color(self.style.rule_color),
2096                        range,
2097                        markdown_end,
2098                    );
2099                    builder.pop_div()
2100                }
2101                MarkdownEvent::SoftBreak => builder.push_text(" ", range.clone()),
2102                MarkdownEvent::HardBreak => builder.push_text("\n", range.clone()),
2103                MarkdownEvent::TaskListMarker(_) => {
2104                    // handled inside the `MarkdownTag::Item` case
2105                }
2106                MarkdownEvent::FootnoteReference(label) => {
2107                    builder.push_footnote_ref(label.clone(), range.clone());
2108                    builder.push_text_style(self.style.link.clone());
2109                    builder.push_text(&format!("[{label}]"), range.clone());
2110                    builder.pop_text_style();
2111                }
2112            }
2113        }
2114        if self.style.code_block_overflow_x_scroll {
2115            let code_block_ids = code_block_ids;
2116            self.markdown.update(cx, move |markdown, _| {
2117                markdown.retain_code_block_scroll_handles(&code_block_ids);
2118            });
2119        } else {
2120            self.markdown
2121                .update(cx, |markdown, _| markdown.clear_code_block_scroll_handles());
2122        }
2123        let mut rendered_markdown = builder.build();
2124        let child_layout_id = rendered_markdown.element.request_layout(window, cx);
2125        let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
2126        (layout_id, rendered_markdown)
2127    }
2128
2129    fn prepaint(
2130        &mut self,
2131        _id: Option<&GlobalElementId>,
2132        _inspector_id: Option<&gpui::InspectorElementId>,
2133        bounds: Bounds<Pixels>,
2134        rendered_markdown: &mut Self::RequestLayoutState,
2135        window: &mut Window,
2136        cx: &mut App,
2137    ) -> Self::PrepaintState {
2138        let focus_handle = self.markdown.read(cx).focus_handle.clone();
2139        window.set_focus_handle(&focus_handle, cx);
2140        window.set_view_id(self.markdown.entity_id());
2141
2142        let hitbox = window.insert_hitbox(bounds, HitboxBehavior::Normal);
2143        rendered_markdown.element.prepaint(window, cx);
2144        self.autoscroll(&rendered_markdown.text, window, cx);
2145        hitbox
2146    }
2147
2148    fn paint(
2149        &mut self,
2150        _id: Option<&GlobalElementId>,
2151        _inspector_id: Option<&gpui::InspectorElementId>,
2152        bounds: Bounds<Pixels>,
2153        rendered_markdown: &mut Self::RequestLayoutState,
2154        hitbox: &mut Self::PrepaintState,
2155        window: &mut Window,
2156        cx: &mut App,
2157    ) {
2158        let mut context = KeyContext::default();
2159        context.add("Markdown");
2160        window.set_key_context(context);
2161        window.on_action(std::any::TypeId::of::<crate::Copy>(), {
2162            let entity = self.markdown.clone();
2163            let text = rendered_markdown.text.clone();
2164            move |_, phase, window, cx| {
2165                let text = text.clone();
2166                if phase == DispatchPhase::Bubble {
2167                    entity.update(cx, move |this, cx| this.copy(&text, window, cx))
2168                }
2169            }
2170        });
2171        window.on_action(std::any::TypeId::of::<crate::CopyAsMarkdown>(), {
2172            let entity = self.markdown.clone();
2173            move |_, phase, window, cx| {
2174                if phase == DispatchPhase::Bubble {
2175                    entity.update(cx, move |this, cx| this.copy_as_markdown(window, cx))
2176                }
2177            }
2178        });
2179
2180        self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
2181        rendered_markdown.element.paint(window, cx);
2182        self.paint_search_highlights(bounds, &rendered_markdown.text, window, cx);
2183        self.paint_selection(bounds, &rendered_markdown.text, window, cx);
2184    }
2185}
2186
2187fn apply_heading_style(
2188    mut heading: Div,
2189    level: pulldown_cmark::HeadingLevel,
2190    custom_styles: Option<&HeadingLevelStyles>,
2191) -> Div {
2192    heading = match level {
2193        pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
2194        pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
2195        pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
2196        pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
2197        pulldown_cmark::HeadingLevel::H5 => heading.text_base(),
2198        pulldown_cmark::HeadingLevel::H6 => heading.text_sm(),
2199    };
2200
2201    if let Some(styles) = custom_styles {
2202        let style_opt = match level {
2203            pulldown_cmark::HeadingLevel::H1 => &styles.h1,
2204            pulldown_cmark::HeadingLevel::H2 => &styles.h2,
2205            pulldown_cmark::HeadingLevel::H3 => &styles.h3,
2206            pulldown_cmark::HeadingLevel::H4 => &styles.h4,
2207            pulldown_cmark::HeadingLevel::H5 => &styles.h5,
2208            pulldown_cmark::HeadingLevel::H6 => &styles.h6,
2209        };
2210
2211        if let Some(style) = style_opt {
2212            heading.style().text = style.clone();
2213        }
2214    }
2215
2216    heading
2217}
2218
2219fn render_copy_code_block_button(
2220    id: usize,
2221    code: String,
2222    markdown: Entity<Markdown>,
2223) -> impl IntoElement {
2224    let id = ElementId::named_usize("copy-markdown-code", id);
2225
2226    CopyButton::new(id.clone(), code.clone()).custom_on_click({
2227        let markdown = markdown;
2228        move |_window, cx| {
2229            let id = id.clone();
2230            markdown.update(cx, |this, cx| {
2231                this.copied_code_blocks.insert(id.clone());
2232
2233                cx.write_to_clipboard(ClipboardItem::new_string(code.clone()));
2234
2235                cx.spawn(async move |this, cx| {
2236                    cx.background_executor().timer(Duration::from_secs(2)).await;
2237
2238                    cx.update(|cx| {
2239                        this.update(cx, |this, cx| {
2240                            this.copied_code_blocks.remove(&id);
2241                            cx.notify();
2242                        })
2243                    })
2244                    .ok();
2245                })
2246                .detach();
2247            });
2248        }
2249    })
2250}
2251
2252impl IntoElement for MarkdownElement {
2253    type Element = Self;
2254
2255    fn into_element(self) -> Self::Element {
2256        self
2257    }
2258}
2259
2260pub enum AnyDiv {
2261    Div(Div),
2262    Stateful(Stateful<Div>),
2263}
2264
2265impl AnyDiv {
2266    fn into_any_element(self) -> AnyElement {
2267        match self {
2268            Self::Div(div) => div.into_any_element(),
2269            Self::Stateful(div) => div.into_any_element(),
2270        }
2271    }
2272}
2273
2274impl From<Div> for AnyDiv {
2275    fn from(value: Div) -> Self {
2276        Self::Div(value)
2277    }
2278}
2279
2280impl From<Stateful<Div>> for AnyDiv {
2281    fn from(value: Stateful<Div>) -> Self {
2282        Self::Stateful(value)
2283    }
2284}
2285
2286impl Styled for AnyDiv {
2287    fn style(&mut self) -> &mut StyleRefinement {
2288        match self {
2289            Self::Div(div) => div.style(),
2290            Self::Stateful(div) => div.style(),
2291        }
2292    }
2293}
2294
2295impl ParentElement for AnyDiv {
2296    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
2297        match self {
2298            Self::Div(div) => div.extend(elements),
2299            Self::Stateful(div) => div.extend(elements),
2300        }
2301    }
2302}
2303
2304#[derive(Default)]
2305struct TableState {
2306    alignments: Vec<Alignment>,
2307    in_head: bool,
2308    row_index: usize,
2309    col_index: usize,
2310}
2311
2312impl TableState {
2313    fn start(&mut self, alignments: Vec<Alignment>) {
2314        self.alignments = alignments;
2315        self.in_head = false;
2316        self.row_index = 0;
2317        self.col_index = 0;
2318    }
2319
2320    fn end(&mut self) {
2321        self.alignments.clear();
2322        self.in_head = false;
2323        self.row_index = 0;
2324        self.col_index = 0;
2325    }
2326
2327    fn start_head(&mut self) {
2328        self.in_head = true;
2329    }
2330
2331    fn end_head(&mut self) {
2332        self.in_head = false;
2333    }
2334
2335    fn start_row(&mut self) {
2336        self.col_index = 0;
2337    }
2338
2339    fn end_row(&mut self) {
2340        self.row_index += 1;
2341    }
2342
2343    fn end_cell(&mut self) {
2344        self.col_index += 1;
2345    }
2346}
2347
2348struct MarkdownElementBuilder {
2349    div_stack: Vec<AnyDiv>,
2350    rendered_lines: Vec<RenderedLine>,
2351    pending_line: PendingLine,
2352    rendered_links: Vec<RenderedLink>,
2353    rendered_footnote_refs: Vec<RenderedFootnoteRef>,
2354    current_source_index: usize,
2355    html_comment: bool,
2356    rendered_footnote_separator: bool,
2357    base_text_style: TextStyle,
2358    text_style_stack: Vec<TextStyleRefinement>,
2359    code_block_stack: Vec<Option<Arc<Language>>>,
2360    list_stack: Vec<ListStackEntry>,
2361    table: TableState,
2362    syntax_theme: Arc<SyntaxTheme>,
2363}
2364
2365#[derive(Default)]
2366struct PendingLine {
2367    text: String,
2368    runs: Vec<TextRun>,
2369    source_mappings: Vec<SourceMapping>,
2370}
2371
2372struct ListStackEntry {
2373    bullet_index: Option<u64>,
2374}
2375
2376impl MarkdownElementBuilder {
2377    fn new(
2378        container_style: &StyleRefinement,
2379        base_text_style: TextStyle,
2380        syntax_theme: Arc<SyntaxTheme>,
2381    ) -> Self {
2382        Self {
2383            div_stack: vec![{
2384                let mut base_div = div();
2385                base_div.style().refine(container_style);
2386                base_div.debug_selector(|| "inner".into()).into()
2387            }],
2388            rendered_lines: Vec::new(),
2389            pending_line: PendingLine::default(),
2390            rendered_links: Vec::new(),
2391            rendered_footnote_refs: Vec::new(),
2392            current_source_index: 0,
2393            html_comment: false,
2394            rendered_footnote_separator: false,
2395            base_text_style,
2396            text_style_stack: Vec::new(),
2397            code_block_stack: Vec::new(),
2398            list_stack: Vec::new(),
2399            table: TableState::default(),
2400            syntax_theme,
2401        }
2402    }
2403
2404    fn push_text_style(&mut self, style: TextStyleRefinement) {
2405        self.text_style_stack.push(style);
2406    }
2407
2408    fn text_style(&self) -> TextStyle {
2409        let mut style = self.base_text_style.clone();
2410        for refinement in &self.text_style_stack {
2411            style.refine(refinement);
2412        }
2413        style
2414    }
2415
2416    fn pop_text_style(&mut self) {
2417        self.text_style_stack.pop();
2418    }
2419
2420    fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
2421        let mut div = div.into();
2422        self.flush_text();
2423
2424        if range.start == 0 {
2425            // Remove the top margin on the first element.
2426            div.style().refine(&StyleRefinement {
2427                margin: gpui::EdgesRefinement {
2428                    top: Some(Length::Definite(px(0.).into())),
2429                    left: None,
2430                    right: None,
2431                    bottom: None,
2432                },
2433                ..Default::default()
2434            });
2435        }
2436
2437        if range.end == markdown_end {
2438            div.style().refine(&StyleRefinement {
2439                margin: gpui::EdgesRefinement {
2440                    top: None,
2441                    left: None,
2442                    right: None,
2443                    bottom: Some(Length::Definite(rems(0.).into())),
2444                },
2445                ..Default::default()
2446            });
2447        }
2448
2449        self.div_stack.push(div);
2450    }
2451
2452    fn push_root_block(&mut self, range: &Range<usize>, markdown_end: usize) {
2453        self.push_div(
2454            div().group("markdown-root-block").relative(),
2455            range,
2456            markdown_end,
2457        );
2458        self.push_div(div().pl_4(), range, markdown_end);
2459    }
2460
2461    fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
2462        self.flush_text();
2463        if let Some(div) = self.div_stack.pop() {
2464            self.div_stack.push(f(div));
2465        }
2466    }
2467
2468    fn pop_root_block(
2469        &mut self,
2470        is_active: bool,
2471        active_gutter_color: Hsla,
2472        hovered_gutter_color: Hsla,
2473    ) {
2474        self.pop_div();
2475        self.modify_current_div(|el| {
2476            el.child(
2477                div()
2478                    .h_full()
2479                    .w(px(4.0))
2480                    .when(is_active, |this| this.bg(active_gutter_color))
2481                    .group_hover("markdown-root-block", |this| {
2482                        if is_active {
2483                            this
2484                        } else {
2485                            this.bg(hovered_gutter_color)
2486                        }
2487                    })
2488                    .rounded_xs()
2489                    .absolute()
2490                    .left_0()
2491                    .top_0(),
2492            )
2493        });
2494        self.pop_div();
2495    }
2496
2497    fn pop_div(&mut self) {
2498        self.flush_text();
2499        let div = self.div_stack.pop().unwrap().into_any_element();
2500        self.div_stack.last_mut().unwrap().extend(iter::once(div));
2501    }
2502
2503    fn push_sourced_element(&mut self, source_range: Range<usize>, element: impl Into<AnyElement>) {
2504        self.flush_text();
2505        let anchor = self.render_source_anchor(source_range);
2506        self.div_stack.last_mut().unwrap().extend([{
2507            div()
2508                .relative()
2509                .child(anchor)
2510                .child(element.into())
2511                .into_any_element()
2512        }]);
2513    }
2514
2515    fn push_list(&mut self, bullet_index: Option<u64>) {
2516        self.list_stack.push(ListStackEntry { bullet_index });
2517    }
2518
2519    fn next_bullet_index(&mut self) -> Option<u64> {
2520        self.list_stack.last_mut().and_then(|entry| {
2521            let item_index = entry.bullet_index.as_mut()?;
2522            *item_index += 1;
2523            Some(*item_index - 1)
2524        })
2525    }
2526
2527    fn pop_list(&mut self) {
2528        self.list_stack.pop();
2529    }
2530
2531    fn push_code_block(&mut self, language: Option<Arc<Language>>) {
2532        self.code_block_stack.push(language);
2533    }
2534
2535    fn pop_code_block(&mut self) {
2536        self.code_block_stack.pop();
2537    }
2538
2539    fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
2540        self.rendered_links.push(RenderedLink {
2541            source_range,
2542            destination_url,
2543        });
2544    }
2545
2546    fn push_footnote_ref(&mut self, label: SharedString, source_range: Range<usize>) {
2547        self.rendered_footnote_refs.push(RenderedFootnoteRef {
2548            source_range,
2549            label,
2550        });
2551    }
2552
2553    fn push_text(&mut self, text: &str, source_range: Range<usize>) {
2554        self.pending_line.source_mappings.push(SourceMapping {
2555            rendered_index: self.pending_line.text.len(),
2556            source_index: source_range.start,
2557        });
2558        self.pending_line.text.push_str(text);
2559        self.current_source_index = source_range.end;
2560
2561        if let Some(Some(language)) = self.code_block_stack.last() {
2562            let mut offset = 0;
2563            for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
2564                if range.start > offset {
2565                    self.pending_line
2566                        .runs
2567                        .push(self.text_style().to_run(range.start - offset));
2568                }
2569
2570                let mut run_style = self.text_style();
2571                if let Some(highlight) = self.syntax_theme.get(highlight_id).cloned() {
2572                    run_style = run_style.highlight(highlight);
2573                }
2574
2575                self.pending_line.runs.push(run_style.to_run(range.len()));
2576                offset = range.end;
2577            }
2578
2579            if offset < text.len() {
2580                self.pending_line
2581                    .runs
2582                    .push(self.text_style().to_run(text.len() - offset));
2583            }
2584        } else {
2585            self.pending_line
2586                .runs
2587                .push(self.text_style().to_run(text.len()));
2588        }
2589    }
2590
2591    fn trim_trailing_newline(&mut self) {
2592        if self.pending_line.text.ends_with('\n') {
2593            self.pending_line
2594                .text
2595                .truncate(self.pending_line.text.len() - 1);
2596            self.pending_line.runs.last_mut().unwrap().len -= 1;
2597            self.current_source_index -= 1;
2598        }
2599    }
2600
2601    fn replace_pending_checkbox(&mut self, source_range: &Range<usize>) {
2602        let trimmed = self.pending_line.text.trim();
2603        if trimmed == "[x]" || trimmed == "[X]" || trimmed == "[ ]" {
2604            let checked = trimmed != "[ ]";
2605            self.pending_line = PendingLine::default();
2606            let checkbox = Checkbox::new(
2607                ElementId::Name(
2608                    format!("table_checkbox_{}_{}", source_range.start, source_range.end).into(),
2609                ),
2610                if checked {
2611                    ToggleState::Selected
2612                } else {
2613                    ToggleState::Unselected
2614                },
2615            )
2616            .fill()
2617            .visualization_only(true)
2618            .into_any_element();
2619            self.div_stack.last_mut().unwrap().extend([checkbox]);
2620        }
2621    }
2622
2623    fn render_source_anchor(&mut self, source_range: Range<usize>) -> AnyElement {
2624        let mut text_style = self.base_text_style.clone();
2625        text_style.color = Hsla::transparent_black();
2626        let text = "\u{200B}";
2627        let styled_text = StyledText::new(text).with_runs(vec![text_style.to_run(text.len())]);
2628        self.rendered_lines.push(RenderedLine {
2629            layout: styled_text.layout().clone(),
2630            source_mappings: vec![SourceMapping {
2631                rendered_index: 0,
2632                source_index: source_range.start,
2633            }],
2634            source_end: source_range.end,
2635            language: None,
2636        });
2637        div()
2638            .absolute()
2639            .top_0()
2640            .left_0()
2641            .opacity(0.)
2642            .child(styled_text)
2643            .into_any_element()
2644    }
2645
2646    fn flush_text(&mut self) {
2647        let line = mem::take(&mut self.pending_line);
2648        if line.text.is_empty() {
2649            return;
2650        }
2651
2652        let text = StyledText::new(line.text).with_runs(line.runs);
2653        self.rendered_lines.push(RenderedLine {
2654            layout: text.layout().clone(),
2655            source_mappings: line.source_mappings,
2656            source_end: self.current_source_index,
2657            language: self.code_block_stack.last().cloned().flatten(),
2658        });
2659        self.div_stack.last_mut().unwrap().extend([text.into_any()]);
2660    }
2661
2662    fn build(mut self) -> RenderedMarkdown {
2663        debug_assert_eq!(self.div_stack.len(), 1);
2664        self.flush_text();
2665        RenderedMarkdown {
2666            element: self.div_stack.pop().unwrap().into_any_element(),
2667            text: RenderedText {
2668                lines: self.rendered_lines.into(),
2669                links: self.rendered_links.into(),
2670                footnote_refs: self.rendered_footnote_refs.into(),
2671            },
2672        }
2673    }
2674}
2675
2676struct RenderedLine {
2677    layout: TextLayout,
2678    source_mappings: Vec<SourceMapping>,
2679    source_end: usize,
2680    language: Option<Arc<Language>>,
2681}
2682
2683impl RenderedLine {
2684    fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
2685        if source_index >= self.source_end {
2686            return self.layout.len();
2687        }
2688
2689        let mapping = match self
2690            .source_mappings
2691            .binary_search_by_key(&source_index, |probe| probe.source_index)
2692        {
2693            Ok(ix) => &self.source_mappings[ix],
2694            Err(ix) => &self.source_mappings[ix - 1],
2695        };
2696        (mapping.rendered_index + (source_index - mapping.source_index)).min(self.layout.len())
2697    }
2698
2699    fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
2700        if rendered_index >= self.layout.len() {
2701            return self.source_end;
2702        }
2703
2704        let mapping = match self
2705            .source_mappings
2706            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
2707        {
2708            Ok(ix) => &self.source_mappings[ix],
2709            Err(ix) => &self.source_mappings[ix - 1],
2710        };
2711        mapping.source_index + (rendered_index - mapping.rendered_index)
2712    }
2713
2714    /// Returns the source index for use as an exclusive range end at a word/selection boundary.
2715    /// When the rendered index is exactly at the start of a segment with a gap from the previous
2716    /// segment (e.g., after stripped markdown syntax like backticks), this returns the end of the
2717    /// previous segment rather than the start of the current one.
2718    fn source_index_for_exclusive_rendered_end(&self, rendered_index: usize) -> usize {
2719        if rendered_index >= self.layout.len() {
2720            return self.source_end;
2721        }
2722
2723        let ix = match self
2724            .source_mappings
2725            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
2726        {
2727            Ok(ix) => ix,
2728            Err(ix) => {
2729                return self.source_mappings[ix - 1].source_index
2730                    + (rendered_index - self.source_mappings[ix - 1].rendered_index);
2731            }
2732        };
2733
2734        // Exact match at the start of a segment. Check if there's a gap from the previous segment.
2735        if ix > 0 {
2736            let prev_mapping = &self.source_mappings[ix - 1];
2737            let mapping = &self.source_mappings[ix];
2738            let prev_segment_len = mapping.rendered_index - prev_mapping.rendered_index;
2739            let prev_source_end = prev_mapping.source_index + prev_segment_len;
2740            if prev_source_end < mapping.source_index {
2741                return prev_source_end;
2742            }
2743        }
2744
2745        self.source_mappings[ix].source_index
2746    }
2747
2748    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2749        let line_rendered_index;
2750        let out_of_bounds;
2751        match self.layout.index_for_position(position) {
2752            Ok(ix) => {
2753                line_rendered_index = ix;
2754                out_of_bounds = false;
2755            }
2756            Err(ix) => {
2757                line_rendered_index = ix;
2758                out_of_bounds = true;
2759            }
2760        };
2761        let source_index = self.source_index_for_rendered_index(line_rendered_index);
2762        if out_of_bounds {
2763            Err(source_index)
2764        } else {
2765            Ok(source_index)
2766        }
2767    }
2768}
2769
2770#[derive(Copy, Clone, Debug, Default)]
2771struct SourceMapping {
2772    rendered_index: usize,
2773    source_index: usize,
2774}
2775
2776pub struct RenderedMarkdown {
2777    element: AnyElement,
2778    text: RenderedText,
2779}
2780
2781#[derive(Clone)]
2782struct RenderedText {
2783    lines: Rc<[RenderedLine]>,
2784    links: Rc<[RenderedLink]>,
2785    footnote_refs: Rc<[RenderedFootnoteRef]>,
2786}
2787
2788#[derive(Debug, Clone, Eq, PartialEq)]
2789struct RenderedLink {
2790    source_range: Range<usize>,
2791    destination_url: SharedString,
2792}
2793
2794#[derive(Debug, Clone, Eq, PartialEq)]
2795struct RenderedFootnoteRef {
2796    source_range: Range<usize>,
2797    label: SharedString,
2798}
2799
2800impl RenderedText {
2801    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2802        let mut lines = self.lines.iter().peekable();
2803        let mut fallback_line: Option<&RenderedLine> = None;
2804
2805        while let Some(line) = lines.next() {
2806            let line_bounds = line.layout.bounds();
2807
2808            // Exact match: position is within bounds (handles overlapping bounds like table columns)
2809            if line_bounds.contains(&position) {
2810                return line.source_index_for_position(position);
2811            }
2812
2813            // Track fallback for Y-coordinate based matching
2814            if position.y <= line_bounds.bottom() && fallback_line.is_none() {
2815                fallback_line = Some(line);
2816            }
2817
2818            // Handle gap between lines
2819            if position.y > line_bounds.bottom() {
2820                if let Some(next_line) = lines.peek()
2821                    && position.y < next_line.layout.bounds().top()
2822                {
2823                    return Err(line.source_end);
2824                }
2825            }
2826        }
2827
2828        // Fall back to Y-coordinate matched line
2829        if let Some(line) = fallback_line {
2830            return line.source_index_for_position(position);
2831        }
2832
2833        Err(self.lines.last().map_or(0, |line| line.source_end))
2834    }
2835
2836    fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
2837        for line in self.lines.iter() {
2838            let line_source_start = line.source_mappings.first().unwrap().source_index;
2839            if source_index < line_source_start {
2840                break;
2841            } else if source_index > line.source_end {
2842                continue;
2843            } else {
2844                let line_height = line.layout.line_height();
2845                let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
2846                let position = line.layout.position_for_index(rendered_index_within_line)?;
2847                return Some((position, line_height));
2848            }
2849        }
2850        None
2851    }
2852
2853    fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
2854        for line in self.lines.iter() {
2855            if source_index > line.source_end {
2856                continue;
2857            }
2858
2859            let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
2860            let rendered_index_in_line =
2861                line.rendered_index_for_source_index(source_index) - line_rendered_start;
2862            let text = line.layout.text();
2863
2864            let scope = line.language.as_ref().map(|l| l.default_scope());
2865            let classifier = CharClassifier::new(scope);
2866
2867            let mut prev_chars = text[..rendered_index_in_line].chars().rev().peekable();
2868            let mut next_chars = text[rendered_index_in_line..].chars().peekable();
2869
2870            let word_kind = std::cmp::max(
2871                prev_chars.peek().map(|&c| classifier.kind(c)),
2872                next_chars.peek().map(|&c| classifier.kind(c)),
2873            );
2874
2875            let mut start = rendered_index_in_line;
2876            for c in prev_chars {
2877                if Some(classifier.kind(c)) == word_kind {
2878                    start -= c.len_utf8();
2879                } else {
2880                    break;
2881                }
2882            }
2883
2884            let mut end = rendered_index_in_line;
2885            for c in next_chars {
2886                if Some(classifier.kind(c)) == word_kind {
2887                    end += c.len_utf8();
2888                } else {
2889                    break;
2890                }
2891            }
2892
2893            return line.source_index_for_rendered_index(line_rendered_start + start)
2894                ..line.source_index_for_exclusive_rendered_end(line_rendered_start + end);
2895        }
2896
2897        source_index..source_index
2898    }
2899
2900    fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
2901        for line in self.lines.iter() {
2902            if source_index > line.source_end {
2903                continue;
2904            }
2905            let line_source_start = line.source_mappings.first().unwrap().source_index;
2906            return line_source_start..line.source_end;
2907        }
2908
2909        source_index..source_index
2910    }
2911
2912    fn text_for_range(&self, range: Range<usize>) -> String {
2913        let mut accumulator = String::new();
2914
2915        for line in self.lines.iter() {
2916            if range.start > line.source_end {
2917                continue;
2918            }
2919            let line_source_start = line.source_mappings.first().unwrap().source_index;
2920            if range.end < line_source_start {
2921                break;
2922            }
2923
2924            let text = line.layout.text();
2925
2926            let start = if range.start < line_source_start {
2927                0
2928            } else {
2929                line.rendered_index_for_source_index(range.start)
2930            };
2931            let end = if range.end > line.source_end {
2932                line.rendered_index_for_source_index(line.source_end)
2933            } else {
2934                line.rendered_index_for_source_index(range.end)
2935            }
2936            .min(text.len());
2937
2938            accumulator.push_str(&text[start..end]);
2939            accumulator.push('\n');
2940        }
2941        // Remove trailing newline
2942        accumulator.pop();
2943        accumulator
2944    }
2945
2946    fn link_for_source_index(&self, source_index: usize) -> Option<&RenderedLink> {
2947        self.links
2948            .iter()
2949            .find(|link| link.source_range.contains(&source_index))
2950    }
2951
2952    fn footnote_ref_for_source_index(&self, source_index: usize) -> Option<&RenderedFootnoteRef> {
2953        self.footnote_refs
2954            .iter()
2955            .find(|fref| fref.source_range.contains(&source_index))
2956    }
2957}
2958
2959#[cfg(test)]
2960mod tests {
2961    use super::*;
2962    use gpui::{TestAppContext, size};
2963    use language::{Language, LanguageConfig, LanguageMatcher};
2964    use std::sync::Arc;
2965
2966    fn ensure_theme_initialized(cx: &mut TestAppContext) {
2967        cx.update(|cx| {
2968            if !cx.has_global::<settings::SettingsStore>() {
2969                settings::init(cx);
2970            }
2971            if !cx.has_global::<theme::GlobalTheme>() {
2972                theme_settings::init(theme::LoadThemes::JustBase, cx);
2973            }
2974        });
2975    }
2976
2977    #[gpui::test]
2978    fn test_mappings(cx: &mut TestAppContext) {
2979        // Formatting.
2980        assert_mappings(
2981            &render_markdown("He*l*lo", cx),
2982            vec![vec![(0, 0), (1, 1), (2, 3), (3, 5), (4, 6), (5, 7)]],
2983        );
2984
2985        // Multiple lines.
2986        assert_mappings(
2987            &render_markdown("Hello\n\nWorld", cx),
2988            vec![
2989                vec![(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)],
2990                vec![(0, 7), (1, 8), (2, 9), (3, 10), (4, 11), (5, 12)],
2991            ],
2992        );
2993
2994        // Multi-byte characters.
2995        assert_mappings(
2996            &render_markdown("αβγ\n\nδεζ", cx),
2997            vec![
2998                vec![(0, 0), (2, 2), (4, 4), (6, 6)],
2999                vec![(0, 8), (2, 10), (4, 12), (6, 14)],
3000            ],
3001        );
3002
3003        // Smart quotes.
3004        assert_mappings(&render_markdown("\"", cx), vec![vec![(0, 0), (3, 1)]]);
3005        assert_mappings(
3006            &render_markdown("\"hey\"", cx),
3007            vec![vec![(0, 0), (3, 1), (4, 2), (5, 3), (6, 4), (9, 5)]],
3008        );
3009
3010        // HTML Comments are ignored
3011        assert_mappings(
3012            &render_markdown(
3013                "<!--\nrdoc-file=string.c\n- str.intern   -> symbol\n- str.to_sym   -> symbol\n-->\nReturns",
3014                cx,
3015            ),
3016            vec![vec![
3017                (0, 78),
3018                (1, 79),
3019                (2, 80),
3020                (3, 81),
3021                (4, 82),
3022                (5, 83),
3023                (6, 84),
3024            ]],
3025        );
3026    }
3027
3028    fn render_markdown(markdown: &str, cx: &mut TestAppContext) -> RenderedText {
3029        render_markdown_with_language_registry(markdown, None, cx)
3030    }
3031
3032    fn render_markdown_with_language_registry(
3033        markdown: &str,
3034        language_registry: Option<Arc<LanguageRegistry>>,
3035        cx: &mut TestAppContext,
3036    ) -> RenderedText {
3037        render_markdown_with_options(markdown, language_registry, MarkdownOptions::default(), cx)
3038    }
3039
3040    fn render_markdown_with_options(
3041        markdown: &str,
3042        language_registry: Option<Arc<LanguageRegistry>>,
3043        options: MarkdownOptions,
3044        cx: &mut TestAppContext,
3045    ) -> RenderedText {
3046        struct TestWindow;
3047
3048        impl Render for TestWindow {
3049            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
3050                div()
3051            }
3052        }
3053
3054        ensure_theme_initialized(cx);
3055
3056        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
3057        let markdown = cx.new(|cx| {
3058            Markdown::new_with_options(
3059                markdown.to_string().into(),
3060                language_registry,
3061                None,
3062                options,
3063                cx,
3064            )
3065        });
3066        cx.run_until_parked();
3067        let (rendered, _) = cx.draw(
3068            Default::default(),
3069            size(px(600.0), px(600.0)),
3070            |_window, _cx| {
3071                MarkdownElement::new(markdown, MarkdownStyle::default()).code_block_renderer(
3072                    CodeBlockRenderer::Default {
3073                        copy_button_visibility: CopyButtonVisibility::Hidden,
3074                        border: false,
3075                    },
3076                )
3077            },
3078        );
3079        rendered.text
3080    }
3081
3082    #[gpui::test]
3083    fn test_surrounding_word_range(cx: &mut TestAppContext) {
3084        let rendered = render_markdown("Hello world tesεζ", cx);
3085
3086        // Test word selection for "Hello"
3087        let word_range = rendered.surrounding_word_range(2); // Simulate click on 'l' in "Hello"
3088        let selected_text = rendered.text_for_range(word_range);
3089        assert_eq!(selected_text, "Hello");
3090
3091        // Test word selection for "world"
3092        let word_range = rendered.surrounding_word_range(7); // Simulate click on 'o' in "world"
3093        let selected_text = rendered.text_for_range(word_range);
3094        assert_eq!(selected_text, "world");
3095
3096        // Test word selection for "tesεζ"
3097        let word_range = rendered.surrounding_word_range(14); // Simulate click on 's' in "tesεζ"
3098        let selected_text = rendered.text_for_range(word_range);
3099        assert_eq!(selected_text, "tesεζ");
3100
3101        // Test word selection at word boundary (space)
3102        let word_range = rendered.surrounding_word_range(5); // Simulate click on space between "Hello" and "world", expect highlighting word to the left
3103        let selected_text = rendered.text_for_range(word_range);
3104        assert_eq!(selected_text, "Hello");
3105    }
3106
3107    #[gpui::test]
3108    fn test_surrounding_line_range(cx: &mut TestAppContext) {
3109        let rendered = render_markdown("First line\n\nSecond line\n\nThird lineεζ", cx);
3110
3111        // Test getting line range for first line
3112        let line_range = rendered.surrounding_line_range(5); // Simulate click somewhere in first line
3113        let selected_text = rendered.text_for_range(line_range);
3114        assert_eq!(selected_text, "First line");
3115
3116        // Test getting line range for second line
3117        let line_range = rendered.surrounding_line_range(13); // Simulate click at beginning in second line
3118        let selected_text = rendered.text_for_range(line_range);
3119        assert_eq!(selected_text, "Second line");
3120
3121        // Test getting line range for third line
3122        let line_range = rendered.surrounding_line_range(37); // Simulate click at end of third line with multi-byte chars
3123        let selected_text = rendered.text_for_range(line_range);
3124        assert_eq!(selected_text, "Third lineεζ");
3125    }
3126
3127    #[gpui::test]
3128    fn test_selection_head_movement(cx: &mut TestAppContext) {
3129        let rendered = render_markdown("Hello world test", cx);
3130
3131        let mut selection = Selection {
3132            start: 5,
3133            end: 5,
3134            reversed: false,
3135            pending: false,
3136            mode: SelectMode::Character,
3137        };
3138
3139        // Test forward selection
3140        selection.set_head(10, &rendered);
3141        assert_eq!(selection.start, 5);
3142        assert_eq!(selection.end, 10);
3143        assert!(!selection.reversed);
3144        assert_eq!(selection.tail(), 5);
3145
3146        // Test backward selection
3147        selection.set_head(2, &rendered);
3148        assert_eq!(selection.start, 2);
3149        assert_eq!(selection.end, 5);
3150        assert!(selection.reversed);
3151        assert_eq!(selection.tail(), 5);
3152
3153        // Test forward selection again from reversed state
3154        selection.set_head(15, &rendered);
3155        assert_eq!(selection.start, 5);
3156        assert_eq!(selection.end, 15);
3157        assert!(!selection.reversed);
3158        assert_eq!(selection.tail(), 5);
3159    }
3160
3161    #[gpui::test]
3162    fn test_word_selection_drag(cx: &mut TestAppContext) {
3163        let rendered = render_markdown("Hello world test", cx);
3164
3165        // Start with a simulated double-click on "world" (index 6-10)
3166        let word_range = rendered.surrounding_word_range(7); // Click on 'o' in "world"
3167        let mut selection = Selection {
3168            start: word_range.start,
3169            end: word_range.end,
3170            reversed: false,
3171            pending: true,
3172            mode: SelectMode::Word(word_range),
3173        };
3174
3175        // Drag forward to "test" - should expand selection to include "test"
3176        selection.set_head(13, &rendered); // Index in "test"
3177        assert_eq!(selection.start, 6); // Start of "world"
3178        assert_eq!(selection.end, 16); // End of "test"
3179        assert!(!selection.reversed);
3180        let selected_text = rendered.text_for_range(selection.start..selection.end);
3181        assert_eq!(selected_text, "world test");
3182
3183        // Drag backward to "Hello" - should expand selection to include "Hello"
3184        selection.set_head(2, &rendered); // Index in "Hello"
3185        assert_eq!(selection.start, 0); // Start of "Hello"
3186        assert_eq!(selection.end, 11); // End of "world" (original selection)
3187        assert!(selection.reversed);
3188        let selected_text = rendered.text_for_range(selection.start..selection.end);
3189        assert_eq!(selected_text, "Hello world");
3190
3191        // Drag back within original word - should revert to original selection
3192        selection.set_head(8, &rendered); // Back within "world"
3193        assert_eq!(selection.start, 6); // Start of "world"
3194        assert_eq!(selection.end, 11); // End of "world"
3195        assert!(!selection.reversed);
3196        let selected_text = rendered.text_for_range(selection.start..selection.end);
3197        assert_eq!(selected_text, "world");
3198    }
3199
3200    #[gpui::test]
3201    fn test_selection_with_markdown_formatting(cx: &mut TestAppContext) {
3202        let rendered = render_markdown(
3203            "This is **bold** text, this is *italic* text, use `code` here",
3204            cx,
3205        );
3206        let word_range = rendered.surrounding_word_range(10); // Inside "bold"
3207        let selected_text = rendered.text_for_range(word_range);
3208        assert_eq!(selected_text, "bold");
3209
3210        let word_range = rendered.surrounding_word_range(32); // Inside "italic"
3211        let selected_text = rendered.text_for_range(word_range);
3212        assert_eq!(selected_text, "italic");
3213
3214        let word_range = rendered.surrounding_word_range(51); // Inside "code"
3215        let selected_text = rendered.text_for_range(word_range);
3216        assert_eq!(selected_text, "code");
3217    }
3218
3219    #[gpui::test]
3220    fn test_table_column_selection(cx: &mut TestAppContext) {
3221        let rendered = render_markdown("| a | b |\n|---|---|\n| c | d |", cx);
3222
3223        assert!(rendered.lines.len() >= 2);
3224        let first_bounds = rendered.lines[0].layout.bounds();
3225        let second_bounds = rendered.lines[1].layout.bounds();
3226
3227        let first_index = match rendered.source_index_for_position(first_bounds.center()) {
3228            Ok(index) | Err(index) => index,
3229        };
3230        let second_index = match rendered.source_index_for_position(second_bounds.center()) {
3231            Ok(index) | Err(index) => index,
3232        };
3233
3234        let first_word = rendered.text_for_range(rendered.surrounding_word_range(first_index));
3235        let second_word = rendered.text_for_range(rendered.surrounding_word_range(second_index));
3236
3237        assert_eq!(first_word, "a");
3238        assert_eq!(second_word, "b");
3239    }
3240
3241    #[test]
3242    fn test_table_checkbox_detection() {
3243        let md = "| Done |\n|------|\n| [x] |\n| [ ] |";
3244        let events = crate::parser::parse_markdown_with_options(md, false, false).events;
3245
3246        let mut in_table = false;
3247        let mut cell_texts: Vec<String> = Vec::new();
3248        let mut current_cell = String::new();
3249
3250        for (range, event) in &events {
3251            match event {
3252                MarkdownEvent::Start(MarkdownTag::Table(_)) => in_table = true,
3253                MarkdownEvent::End(MarkdownTagEnd::Table) => in_table = false,
3254                MarkdownEvent::Start(MarkdownTag::TableCell) => current_cell.clear(),
3255                MarkdownEvent::End(MarkdownTagEnd::TableCell) => {
3256                    if in_table {
3257                        cell_texts.push(current_cell.clone());
3258                    }
3259                }
3260                MarkdownEvent::Text if in_table => {
3261                    current_cell.push_str(&md[range.clone()]);
3262                }
3263                _ => {}
3264            }
3265        }
3266
3267        let checkbox_cells: Vec<&String> = cell_texts
3268            .iter()
3269            .filter(|t| {
3270                let trimmed = t.trim();
3271                trimmed == "[x]" || trimmed == "[X]" || trimmed == "[ ]"
3272            })
3273            .collect();
3274        assert_eq!(
3275            checkbox_cells.len(),
3276            2,
3277            "Expected 2 checkbox cells, got: {cell_texts:?}"
3278        );
3279        assert_eq!(checkbox_cells[0].trim(), "[x]");
3280        assert_eq!(checkbox_cells[1].trim(), "[ ]");
3281    }
3282
3283    #[gpui::test]
3284    fn test_inline_code_word_selection_excludes_backticks(cx: &mut TestAppContext) {
3285        // Test that double-clicking on inline code selects just the code content,
3286        // not the backticks. This verifies the fix for the bug where selecting
3287        // inline code would include the trailing backtick.
3288        let rendered = render_markdown("use `blah` here", cx);
3289
3290        // Source layout: "use `blah` here"
3291        //                 0123456789...
3292        // The inline code "blah" is at source positions 5-8 (content range 5..9)
3293
3294        // Click inside "blah" - should select just "blah", not "blah`"
3295        let word_range = rendered.surrounding_word_range(6); // 'l' in "blah"
3296
3297        // text_for_range extracts from the rendered text (without backticks), so it
3298        // would return "blah" even with a wrong source range. We check it anyway.
3299        let selected_text = rendered.text_for_range(word_range.clone());
3300        assert_eq!(selected_text, "blah");
3301
3302        // The source range is what matters for copy_as_markdown and selected_text,
3303        // which extract directly from the source. With the bug, this would be 5..10
3304        // which includes the closing backtick at position 9.
3305        assert_eq!(word_range, 5..9);
3306    }
3307
3308    #[gpui::test]
3309    fn test_surrounding_word_range_respects_word_characters(cx: &mut TestAppContext) {
3310        let rendered = render_markdown("foo.bar() baz", cx);
3311
3312        // Double clicking on 'f' in "foo" - should select just "foo"
3313        let word_range = rendered.surrounding_word_range(0);
3314        let selected_text = rendered.text_for_range(word_range);
3315        assert_eq!(selected_text, "foo");
3316
3317        // Double clicking on 'b' in "bar" - should select just "bar"
3318        let word_range = rendered.surrounding_word_range(4);
3319        let selected_text = rendered.text_for_range(word_range);
3320        assert_eq!(selected_text, "bar");
3321
3322        // Double clicking on 'b' in "baz" - should select "baz"
3323        let word_range = rendered.surrounding_word_range(10);
3324        let selected_text = rendered.text_for_range(word_range);
3325        assert_eq!(selected_text, "baz");
3326
3327        // Double clicking selects word characters in code blocks
3328        let javascript_language = Arc::new(Language::new(
3329            LanguageConfig {
3330                name: "JavaScript".into(),
3331                matcher: LanguageMatcher {
3332                    path_suffixes: vec!["js".to_string()],
3333                    ..Default::default()
3334                },
3335                word_characters: ['$', '#'].into_iter().collect(),
3336                ..Default::default()
3337            },
3338            None,
3339        ));
3340
3341        let language_registry = Arc::new(LanguageRegistry::test(cx.executor()));
3342        language_registry.add(javascript_language);
3343
3344        let rendered = render_markdown_with_language_registry(
3345            "```javascript\n$foo #bar\n```",
3346            Some(language_registry),
3347            cx,
3348        );
3349
3350        let word_range = rendered.surrounding_word_range(14);
3351        let selected_text = rendered.text_for_range(word_range);
3352        assert_eq!(selected_text, "$foo");
3353
3354        let word_range = rendered.surrounding_word_range(19);
3355        let selected_text = rendered.text_for_range(word_range);
3356        assert_eq!(selected_text, "#bar");
3357    }
3358
3359    #[gpui::test]
3360    fn test_all_selection(cx: &mut TestAppContext) {
3361        let rendered = render_markdown("Hello world\n\nThis is a test\n\nwith multiple lines", cx);
3362
3363        let total_length = rendered
3364            .lines
3365            .last()
3366            .map(|line| line.source_end)
3367            .unwrap_or(0);
3368
3369        let mut selection = Selection {
3370            start: 0,
3371            end: total_length,
3372            reversed: false,
3373            pending: true,
3374            mode: SelectMode::All,
3375        };
3376
3377        selection.set_head(5, &rendered); // Try to set head in middle
3378        assert_eq!(selection.start, 0);
3379        assert_eq!(selection.end, total_length);
3380        assert!(!selection.reversed);
3381
3382        selection.set_head(25, &rendered); // Try to set head near end
3383        assert_eq!(selection.start, 0);
3384        assert_eq!(selection.end, total_length);
3385        assert!(!selection.reversed);
3386
3387        let selected_text = rendered.text_for_range(selection.start..selection.end);
3388        assert_eq!(
3389            selected_text,
3390            "Hello world\nThis is a test\nwith multiple lines"
3391        );
3392    }
3393
3394    fn nbsp(n: usize) -> String {
3395        "\u{00A0}".repeat(n)
3396    }
3397
3398    #[test]
3399    fn test_escape_plain_text() {
3400        assert_eq!(Markdown::escape("hello world"), "hello world");
3401        assert_eq!(Markdown::escape(""), "");
3402        assert_eq!(Markdown::escape("café ☕ naïve"), "café ☕ naïve");
3403    }
3404
3405    #[test]
3406    fn test_escape_punctuation() {
3407        assert_eq!(Markdown::escape("hello `world`"), r"hello \`world\`");
3408        assert_eq!(Markdown::escape("a|b"), r"a\|b");
3409    }
3410
3411    #[test]
3412    fn test_escape_leading_spaces() {
3413        assert_eq!(Markdown::escape("    hello"), [&nbsp(4), "hello"].concat());
3414        assert_eq!(
3415            Markdown::escape("    | { a: string }"),
3416            [&nbsp(4), r"\| \{ a\: string \}"].concat()
3417        );
3418        assert_eq!(
3419            Markdown::escape("  first\n  second"),
3420            [&nbsp(2), "first\n\n", &nbsp(2), "second"].concat()
3421        );
3422        assert_eq!(Markdown::escape("hello   world"), "hello   world");
3423    }
3424
3425    #[test]
3426    fn test_escape_leading_tabs() {
3427        assert_eq!(Markdown::escape("\thello"), [&nbsp(4), "hello"].concat());
3428        assert_eq!(
3429            Markdown::escape("hello\n\t\tindented"),
3430            ["hello\n\n", &nbsp(8), "indented"].concat()
3431        );
3432        assert_eq!(
3433            Markdown::escape(" \t hello"),
3434            [&nbsp(1 + 4 + 1), "hello"].concat()
3435        );
3436        assert_eq!(Markdown::escape("hello\tworld"), "hello\tworld");
3437    }
3438
3439    #[test]
3440    fn test_escape_newlines() {
3441        assert_eq!(Markdown::escape("a\nb"), "a\n\nb");
3442        assert_eq!(Markdown::escape("a\n\nb"), "a\n\n\n\nb");
3443        assert_eq!(Markdown::escape("\nhello"), "\n\nhello");
3444    }
3445
3446    #[test]
3447    fn test_escape_multiline_diagnostic() {
3448        assert_eq!(
3449            Markdown::escape("    | { a: string }\n    | { b: number }"),
3450            [
3451                &nbsp(4),
3452                r"\| \{ a\: string \}",
3453                "\n\n",
3454                &nbsp(4),
3455                r"\| \{ b\: number \}",
3456            ]
3457            .concat()
3458        );
3459    }
3460
3461    fn has_code_block(markdown: &str) -> bool {
3462        let parsed_data = parse_markdown_with_options(markdown, false, false);
3463        parsed_data
3464            .events
3465            .iter()
3466            .any(|(_, event)| matches!(event, MarkdownEvent::Start(MarkdownTag::CodeBlock { .. })))
3467    }
3468
3469    #[test]
3470    fn test_escape_output_len_matches_precomputed() {
3471        let cases = [
3472            "",
3473            "hello world",
3474            "hello `world`",
3475            "    hello",
3476            "    | { a: string }",
3477            "\thello",
3478            "hello\n\t\tindented",
3479            " \t hello",
3480            "hello\tworld",
3481            "a\nb",
3482            "a\n\nb",
3483            "\nhello",
3484            "    | { a: string }\n    | { b: number }",
3485            "café ☕ naïve",
3486        ];
3487        for input in cases {
3488            let mut escaper = MarkdownEscaper::new();
3489            let precomputed: usize = input.bytes().map(|b| escaper.next(b).output_len()).sum();
3490
3491            let mut escaper = MarkdownEscaper::new();
3492            let mut output = String::new();
3493            for c in input.chars() {
3494                escaper.next(c as u8).write_to(c, &mut output);
3495            }
3496
3497            assert_eq!(precomputed, output.len(), "length mismatch for {:?}", input);
3498        }
3499    }
3500
3501    #[test]
3502    fn test_escape_prevents_code_block() {
3503        let diagnostic = "    | { a: string }";
3504        assert!(has_code_block(diagnostic));
3505        assert!(!has_code_block(&Markdown::escape(diagnostic)));
3506    }
3507
3508    #[gpui::test]
3509    fn test_link_detected_for_source_index(cx: &mut TestAppContext) {
3510        let rendered = render_markdown("[Click here](https://example.com)", cx);
3511
3512        assert_eq!(rendered.links.len(), 1);
3513        assert_eq!(rendered.links[0].destination_url, "https://example.com");
3514
3515        // Source index 1 ('C' in "Click") is inside the link's source range
3516        let link = rendered.link_for_source_index(1);
3517        assert!(link.is_some());
3518        assert_eq!(link.unwrap().destination_url, "https://example.com");
3519
3520        // A source index past the end of the link range returns None
3521        let past_end = rendered.links[0].source_range.end;
3522        assert!(rendered.link_for_source_index(past_end).is_none());
3523    }
3524
3525    #[gpui::test]
3526    fn test_link_for_source_index_ignores_plain_text(cx: &mut TestAppContext) {
3527        let rendered = render_markdown("Hello world", cx);
3528
3529        assert!(rendered.links.is_empty());
3530        assert!(rendered.link_for_source_index(0).is_none());
3531        assert!(rendered.link_for_source_index(5).is_none());
3532    }
3533
3534    #[gpui::test]
3535    fn test_context_menu_link_initial_state(cx: &mut TestAppContext) {
3536        struct TestWindow;
3537        impl Render for TestWindow {
3538            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
3539                div()
3540            }
3541        }
3542
3543        ensure_theme_initialized(cx);
3544        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
3545        let markdown =
3546            cx.new(|cx| Markdown::new("Hello [world](https://example.com)".into(), None, None, cx));
3547        cx.run_until_parked();
3548
3549        cx.update(|_window, cx| {
3550            assert!(markdown.read(cx).context_menu_link().is_none());
3551        });
3552    }
3553
3554    #[gpui::test]
3555    fn test_capture_for_context_menu(cx: &mut TestAppContext) {
3556        struct TestWindow;
3557        impl Render for TestWindow {
3558            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
3559                div()
3560            }
3561        }
3562
3563        ensure_theme_initialized(cx);
3564        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
3565        let markdown = cx.new(|cx| Markdown::new("text".into(), None, None, cx));
3566        cx.run_until_parked();
3567
3568        // Simulates right-clicking on a link
3569        let url: SharedString = "https://example.com".into();
3570        markdown.update(cx, |md, _cx| {
3571            md.capture_for_context_menu(Some(url.clone()));
3572        });
3573        cx.update(|_window, cx| {
3574            assert_eq!(
3575                markdown
3576                    .read(cx)
3577                    .context_menu_link()
3578                    .map(SharedString::as_ref),
3579                Some("https://example.com")
3580            );
3581        });
3582
3583        // Simulates right-clicking on plain text — link is cleared
3584        markdown.update(cx, |md, _cx| {
3585            md.capture_for_context_menu(None);
3586        });
3587        cx.update(|_window, cx| {
3588            assert!(markdown.read(cx).context_menu_link().is_none());
3589        });
3590    }
3591
3592    #[track_caller]
3593    fn assert_mappings(rendered: &RenderedText, expected: Vec<Vec<(usize, usize)>>) {
3594        assert_eq!(rendered.lines.len(), expected.len(), "line count mismatch");
3595        for (line_ix, line_mappings) in expected.into_iter().enumerate() {
3596            let line = &rendered.lines[line_ix];
3597
3598            assert!(
3599                line.source_mappings.windows(2).all(|mappings| {
3600                    mappings[0].source_index < mappings[1].source_index
3601                        && mappings[0].rendered_index < mappings[1].rendered_index
3602                }),
3603                "line {} has duplicate mappings: {:?}",
3604                line_ix,
3605                line.source_mappings
3606            );
3607
3608            for (rendered_ix, source_ix) in line_mappings {
3609                assert_eq!(
3610                    line.source_index_for_rendered_index(rendered_ix),
3611                    source_ix,
3612                    "line {}, rendered_ix {}",
3613                    line_ix,
3614                    rendered_ix
3615                );
3616
3617                assert_eq!(
3618                    line.rendered_index_for_source_index(source_ix),
3619                    rendered_ix,
3620                    "line {}, source_ix {}",
3621                    line_ix,
3622                    source_ix
3623                );
3624            }
3625        }
3626    }
3627
3628    #[gpui::test]
3629    fn test_heading_font_sizes_are_distinct(cx: &mut TestAppContext) {
3630        let rendered = render_markdown("# H1\n\n## H2\n\n### H3\n\nBody text", cx);
3631
3632        assert!(
3633            rendered.lines.len() >= 4,
3634            "expected at least 4 rendered lines, got {}",
3635            rendered.lines.len()
3636        );
3637
3638        let h1_line_height = rendered.lines[0].layout.line_height();
3639        let h2_line_height = rendered.lines[1].layout.line_height();
3640        let h3_line_height = rendered.lines[2].layout.line_height();
3641        let body_line_height = rendered.lines[3].layout.line_height();
3642
3643        assert!(
3644            h1_line_height > h2_line_height,
3645            "H1 line height ({h1_line_height:?}) should be greater than H2 ({h2_line_height:?})"
3646        );
3647        assert!(
3648            h2_line_height > h3_line_height,
3649            "H2 line height ({h2_line_height:?}) should be greater than H3 ({h3_line_height:?})"
3650        );
3651        assert!(
3652            h3_line_height > body_line_height,
3653            "H3 line height ({h3_line_height:?}) should be greater than body text ({body_line_height:?})"
3654        );
3655    }
3656}