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