markdown.rs

   1pub mod parser;
   2mod path_range;
   3
   4use base64::Engine as _;
   5use futures::FutureExt as _;
   6use gpui::EdgesRefinement;
   7use gpui::HitboxBehavior;
   8use gpui::UnderlineStyle;
   9use language::LanguageName;
  10use log::Level;
  11pub use path_range::{LineCol, PathWithRange};
  12use settings::Settings as _;
  13use theme::ThemeSettings;
  14use ui::Checkbox;
  15use ui::CopyButton;
  16
  17use std::borrow::Cow;
  18use std::collections::BTreeMap;
  19use std::iter;
  20use std::mem;
  21use std::ops::Range;
  22use std::path::Path;
  23use std::rc::Rc;
  24use std::sync::Arc;
  25use std::time::Duration;
  26
  27use collections::{HashMap, HashSet};
  28use gpui::{
  29    AnyElement, App, BorderStyle, Bounds, ClipboardItem, CursorStyle, DispatchPhase, Edges, Entity,
  30    FocusHandle, Focusable, FontStyle, FontWeight, GlobalElementId, Hitbox, Hsla, Image,
  31    ImageFormat, KeyContext, Length, MouseButton, MouseDownEvent, MouseEvent, MouseMoveEvent,
  32    MouseUpEvent, Point, ScrollHandle, Stateful, StrikethroughStyle, StyleRefinement, StyledText,
  33    Task, TextLayout, TextRun, TextStyle, TextStyleRefinement, actions, img, point, quad,
  34};
  35use language::{CharClassifier, Language, LanguageRegistry, Rope};
  36use parser::CodeBlockMetadata;
  37use parser::{MarkdownEvent, MarkdownTag, MarkdownTagEnd, parse_links_only, parse_markdown};
  38use pulldown_cmark::Alignment;
  39use sum_tree::TreeMap;
  40use theme::SyntaxTheme;
  41use ui::{ScrollAxes, Scrollbars, WithScrollbar, prelude::*};
  42use util::ResultExt;
  43
  44use crate::parser::CodeBlockKind;
  45
  46/// A callback function that can be used to customize the style of links based on the destination URL.
  47/// If the callback returns `None`, the default link style will be used.
  48type LinkStyleCallback = Rc<dyn Fn(&str, &App) -> Option<TextStyleRefinement>>;
  49
  50/// Defines custom style refinements for each heading level (H1-H6)
  51#[derive(Clone, Default)]
  52pub struct HeadingLevelStyles {
  53    pub h1: Option<TextStyleRefinement>,
  54    pub h2: Option<TextStyleRefinement>,
  55    pub h3: Option<TextStyleRefinement>,
  56    pub h4: Option<TextStyleRefinement>,
  57    pub h5: Option<TextStyleRefinement>,
  58    pub h6: Option<TextStyleRefinement>,
  59}
  60
  61#[derive(Clone)]
  62pub struct MarkdownStyle {
  63    pub base_text_style: TextStyle,
  64    pub container_style: StyleRefinement,
  65    pub code_block: StyleRefinement,
  66    pub code_block_overflow_x_scroll: bool,
  67    pub inline_code: TextStyleRefinement,
  68    pub block_quote: TextStyleRefinement,
  69    pub link: TextStyleRefinement,
  70    pub link_callback: Option<LinkStyleCallback>,
  71    pub rule_color: Hsla,
  72    pub block_quote_border_color: Hsla,
  73    pub syntax: Arc<SyntaxTheme>,
  74    pub selection_background_color: Hsla,
  75    pub heading: StyleRefinement,
  76    pub heading_level_styles: Option<HeadingLevelStyles>,
  77    pub height_is_multiple_of_line_height: bool,
  78    pub prevent_mouse_interaction: bool,
  79    pub table_columns_min_size: bool,
  80}
  81
  82impl Default for MarkdownStyle {
  83    fn default() -> Self {
  84        Self {
  85            base_text_style: Default::default(),
  86            container_style: Default::default(),
  87            code_block: Default::default(),
  88            code_block_overflow_x_scroll: false,
  89            inline_code: Default::default(),
  90            block_quote: Default::default(),
  91            link: Default::default(),
  92            link_callback: None,
  93            rule_color: Default::default(),
  94            block_quote_border_color: Default::default(),
  95            syntax: Arc::new(SyntaxTheme::default()),
  96            selection_background_color: Default::default(),
  97            heading: Default::default(),
  98            heading_level_styles: None,
  99            height_is_multiple_of_line_height: false,
 100            prevent_mouse_interaction: false,
 101            table_columns_min_size: false,
 102        }
 103    }
 104}
 105
 106pub enum MarkdownFont {
 107    Agent,
 108    Editor,
 109}
 110
 111impl MarkdownStyle {
 112    pub fn themed(font: MarkdownFont, window: &Window, cx: &App) -> Self {
 113        let theme_settings = ThemeSettings::get_global(cx);
 114        let colors = cx.theme().colors();
 115
 116        let buffer_font_weight = theme_settings.buffer_font.weight;
 117        let (buffer_font_size, ui_font_size) = match font {
 118            MarkdownFont::Agent => (
 119                theme_settings.agent_buffer_font_size(cx),
 120                theme_settings.agent_ui_font_size(cx),
 121            ),
 122            MarkdownFont::Editor => (
 123                theme_settings.buffer_font_size(cx),
 124                theme_settings.ui_font_size(cx),
 125            ),
 126        };
 127
 128        let text_color = colors.text;
 129
 130        let mut text_style = window.text_style();
 131        let line_height = buffer_font_size * 1.75;
 132
 133        text_style.refine(&TextStyleRefinement {
 134            font_family: Some(theme_settings.ui_font.family.clone()),
 135            font_fallbacks: theme_settings.ui_font.fallbacks.clone(),
 136            font_features: Some(theme_settings.ui_font.features.clone()),
 137            font_size: Some(ui_font_size.into()),
 138            line_height: Some(line_height.into()),
 139            color: Some(text_color),
 140            ..Default::default()
 141        });
 142
 143        MarkdownStyle {
 144            base_text_style: text_style.clone(),
 145            syntax: cx.theme().syntax().clone(),
 146            selection_background_color: colors.element_selection_background,
 147            code_block_overflow_x_scroll: true,
 148            heading_level_styles: Some(HeadingLevelStyles {
 149                h1: Some(TextStyleRefinement {
 150                    font_size: Some(rems(1.15).into()),
 151                    ..Default::default()
 152                }),
 153                h2: Some(TextStyleRefinement {
 154                    font_size: Some(rems(1.1).into()),
 155                    ..Default::default()
 156                }),
 157                h3: Some(TextStyleRefinement {
 158                    font_size: Some(rems(1.05).into()),
 159                    ..Default::default()
 160                }),
 161                h4: Some(TextStyleRefinement {
 162                    font_size: Some(rems(1.).into()),
 163                    ..Default::default()
 164                }),
 165                h5: Some(TextStyleRefinement {
 166                    font_size: Some(rems(0.95).into()),
 167                    ..Default::default()
 168                }),
 169                h6: Some(TextStyleRefinement {
 170                    font_size: Some(rems(0.875).into()),
 171                    ..Default::default()
 172                }),
 173            }),
 174            code_block: StyleRefinement {
 175                padding: EdgesRefinement {
 176                    top: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 177                    left: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 178                    right: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 179                    bottom: Some(DefiniteLength::Absolute(AbsoluteLength::Pixels(px(8.)))),
 180                },
 181                margin: EdgesRefinement {
 182                    top: Some(Length::Definite(px(8.).into())),
 183                    left: Some(Length::Definite(px(0.).into())),
 184                    right: Some(Length::Definite(px(0.).into())),
 185                    bottom: Some(Length::Definite(px(12.).into())),
 186                },
 187                border_style: Some(BorderStyle::Solid),
 188                border_widths: EdgesRefinement {
 189                    top: Some(AbsoluteLength::Pixels(px(1.))),
 190                    left: Some(AbsoluteLength::Pixels(px(1.))),
 191                    right: Some(AbsoluteLength::Pixels(px(1.))),
 192                    bottom: Some(AbsoluteLength::Pixels(px(1.))),
 193                },
 194                border_color: Some(colors.border_variant),
 195                background: Some(colors.editor_background.into()),
 196                text: TextStyleRefinement {
 197                    font_family: Some(theme_settings.buffer_font.family.clone()),
 198                    font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 199                    font_features: Some(theme_settings.buffer_font.features.clone()),
 200                    font_size: Some(buffer_font_size.into()),
 201                    font_weight: Some(buffer_font_weight),
 202                    ..Default::default()
 203                },
 204                ..Default::default()
 205            },
 206            inline_code: TextStyleRefinement {
 207                font_family: Some(theme_settings.buffer_font.family.clone()),
 208                font_fallbacks: theme_settings.buffer_font.fallbacks.clone(),
 209                font_features: Some(theme_settings.buffer_font.features.clone()),
 210                font_size: Some(buffer_font_size.into()),
 211                font_weight: Some(buffer_font_weight),
 212                background_color: Some(colors.editor_foreground.opacity(0.08)),
 213                ..Default::default()
 214            },
 215            link: TextStyleRefinement {
 216                background_color: Some(colors.editor_foreground.opacity(0.025)),
 217                color: Some(colors.text_accent),
 218                underline: Some(UnderlineStyle {
 219                    color: Some(colors.text_accent.opacity(0.5)),
 220                    thickness: px(1.),
 221                    ..Default::default()
 222                }),
 223                ..Default::default()
 224            },
 225            ..Default::default()
 226        }
 227    }
 228
 229    pub fn with_muted_text(mut self, cx: &App) -> Self {
 230        let colors = cx.theme().colors();
 231        self.base_text_style.color = colors.text_muted;
 232        self
 233    }
 234}
 235
 236pub struct Markdown {
 237    source: SharedString,
 238    selection: Selection,
 239    pressed_link: Option<RenderedLink>,
 240    autoscroll_request: Option<usize>,
 241    parsed_markdown: ParsedMarkdown,
 242    images_by_source_offset: HashMap<usize, Arc<Image>>,
 243    should_reparse: bool,
 244    pending_parse: Option<Task<()>>,
 245    focus_handle: FocusHandle,
 246    language_registry: Option<Arc<LanguageRegistry>>,
 247    fallback_code_block_language: Option<LanguageName>,
 248    options: Options,
 249    copied_code_blocks: HashSet<ElementId>,
 250    code_block_scroll_handles: BTreeMap<usize, ScrollHandle>,
 251    context_menu_selected_text: Option<String>,
 252}
 253
 254struct Options {
 255    parse_links_only: bool,
 256}
 257
 258pub enum CodeBlockRenderer {
 259    Default {
 260        copy_button: bool,
 261        copy_button_on_hover: bool,
 262        border: bool,
 263    },
 264    Custom {
 265        render: CodeBlockRenderFn,
 266        /// A function that can modify the parent container after the code block
 267        /// content has been appended as a child element.
 268        transform: Option<CodeBlockTransformFn>,
 269    },
 270}
 271
 272pub type CodeBlockRenderFn = Arc<
 273    dyn Fn(
 274        &CodeBlockKind,
 275        &ParsedMarkdown,
 276        Range<usize>,
 277        CodeBlockMetadata,
 278        &mut Window,
 279        &App,
 280    ) -> Div,
 281>;
 282
 283pub type CodeBlockTransformFn =
 284    Arc<dyn Fn(AnyDiv, Range<usize>, CodeBlockMetadata, &mut Window, &App) -> AnyDiv>;
 285
 286actions!(
 287    markdown,
 288    [
 289        /// Copies the selected text to the clipboard.
 290        Copy,
 291        /// Copies the selected text as markdown to the clipboard.
 292        CopyAsMarkdown
 293    ]
 294);
 295
 296impl Markdown {
 297    pub fn new(
 298        source: SharedString,
 299        language_registry: Option<Arc<LanguageRegistry>>,
 300        fallback_code_block_language: Option<LanguageName>,
 301        cx: &mut Context<Self>,
 302    ) -> Self {
 303        let focus_handle = cx.focus_handle();
 304        let mut this = Self {
 305            source,
 306            selection: Selection::default(),
 307            pressed_link: None,
 308            autoscroll_request: None,
 309            should_reparse: false,
 310            images_by_source_offset: Default::default(),
 311            parsed_markdown: ParsedMarkdown::default(),
 312            pending_parse: None,
 313            focus_handle,
 314            language_registry,
 315            fallback_code_block_language,
 316            options: Options {
 317                parse_links_only: false,
 318            },
 319            copied_code_blocks: HashSet::default(),
 320            code_block_scroll_handles: BTreeMap::default(),
 321            context_menu_selected_text: None,
 322        };
 323        this.parse(cx);
 324        this
 325    }
 326
 327    pub fn new_text(source: SharedString, cx: &mut Context<Self>) -> Self {
 328        let focus_handle = cx.focus_handle();
 329        let mut this = Self {
 330            source,
 331            selection: Selection::default(),
 332            pressed_link: None,
 333            autoscroll_request: None,
 334            should_reparse: false,
 335            parsed_markdown: ParsedMarkdown::default(),
 336            images_by_source_offset: Default::default(),
 337            pending_parse: None,
 338            focus_handle,
 339            language_registry: None,
 340            fallback_code_block_language: None,
 341            options: Options {
 342                parse_links_only: true,
 343            },
 344            copied_code_blocks: HashSet::default(),
 345            code_block_scroll_handles: BTreeMap::default(),
 346            context_menu_selected_text: None,
 347        };
 348        this.parse(cx);
 349        this
 350    }
 351
 352    fn code_block_scroll_handle(&mut self, id: usize) -> ScrollHandle {
 353        self.code_block_scroll_handles
 354            .entry(id)
 355            .or_insert_with(ScrollHandle::new)
 356            .clone()
 357    }
 358
 359    fn retain_code_block_scroll_handles(&mut self, ids: &HashSet<usize>) {
 360        self.code_block_scroll_handles
 361            .retain(|id, _| ids.contains(id));
 362    }
 363
 364    fn clear_code_block_scroll_handles(&mut self) {
 365        self.code_block_scroll_handles.clear();
 366    }
 367
 368    fn autoscroll_code_block(&self, source_index: usize, cursor_position: Point<Pixels>) {
 369        let Some((_, scroll_handle)) = self
 370            .code_block_scroll_handles
 371            .range(..=source_index)
 372            .next_back()
 373        else {
 374            return;
 375        };
 376
 377        let bounds = scroll_handle.bounds();
 378        if cursor_position.y < bounds.top() || cursor_position.y > bounds.bottom() {
 379            return;
 380        }
 381
 382        let horizontal_delta = if cursor_position.x < bounds.left() {
 383            bounds.left() - cursor_position.x
 384        } else if cursor_position.x > bounds.right() {
 385            bounds.right() - cursor_position.x
 386        } else {
 387            return;
 388        };
 389
 390        let offset = scroll_handle.offset();
 391        scroll_handle.set_offset(point(offset.x + horizontal_delta, offset.y));
 392    }
 393
 394    pub fn is_parsing(&self) -> bool {
 395        self.pending_parse.is_some()
 396    }
 397
 398    pub fn source(&self) -> &str {
 399        &self.source
 400    }
 401
 402    pub fn append(&mut self, text: &str, cx: &mut Context<Self>) {
 403        self.source = SharedString::new(self.source.to_string() + text);
 404        self.parse(cx);
 405    }
 406
 407    pub fn replace(&mut self, source: impl Into<SharedString>, cx: &mut Context<Self>) {
 408        self.source = source.into();
 409        self.parse(cx);
 410    }
 411
 412    pub fn reset(&mut self, source: SharedString, cx: &mut Context<Self>) {
 413        if source == self.source() {
 414            return;
 415        }
 416        self.source = source;
 417        self.selection = Selection::default();
 418        self.autoscroll_request = None;
 419        self.pending_parse = None;
 420        self.should_reparse = false;
 421        // Don't clear parsed_markdown here - keep existing content visible until new parse completes
 422        self.parse(cx);
 423    }
 424
 425    #[cfg(any(test, feature = "test-support"))]
 426    pub fn parsed_markdown(&self) -> &ParsedMarkdown {
 427        &self.parsed_markdown
 428    }
 429
 430    pub fn escape(s: &str) -> Cow<'_, str> {
 431        // Valid to use bytes since multi-byte UTF-8 doesn't use ASCII chars.
 432        let count = s
 433            .bytes()
 434            .filter(|c| *c == b'\n' || c.is_ascii_punctuation())
 435            .count();
 436        if count > 0 {
 437            let mut output = String::with_capacity(s.len() + count);
 438            let mut is_newline = false;
 439            for c in s.chars() {
 440                if is_newline && c == ' ' {
 441                    continue;
 442                }
 443                is_newline = c == '\n';
 444                if c == '\n' {
 445                    output.push('\n')
 446                } else if c.is_ascii_punctuation() {
 447                    output.push('\\')
 448                }
 449                output.push(c)
 450            }
 451            output.into()
 452        } else {
 453            s.into()
 454        }
 455    }
 456
 457    pub fn selected_text(&self) -> Option<String> {
 458        if self.selection.end <= self.selection.start {
 459            None
 460        } else {
 461            Some(self.source[self.selection.start..self.selection.end].to_string())
 462        }
 463    }
 464
 465    fn copy(&self, text: &RenderedText, _: &mut Window, cx: &mut Context<Self>) {
 466        if self.selection.end <= self.selection.start {
 467            return;
 468        }
 469        let text = text.text_for_range(self.selection.start..self.selection.end);
 470        cx.write_to_clipboard(ClipboardItem::new_string(text));
 471    }
 472
 473    fn copy_as_markdown(&mut self, _: &mut Window, cx: &mut Context<Self>) {
 474        if let Some(text) = self.context_menu_selected_text.take() {
 475            cx.write_to_clipboard(ClipboardItem::new_string(text));
 476            return;
 477        }
 478        if self.selection.end <= self.selection.start {
 479            return;
 480        }
 481        let text = self.source[self.selection.start..self.selection.end].to_string();
 482        cx.write_to_clipboard(ClipboardItem::new_string(text));
 483    }
 484
 485    fn capture_selection_for_context_menu(&mut self) {
 486        self.context_menu_selected_text = self.selected_text();
 487    }
 488
 489    fn parse(&mut self, cx: &mut Context<Self>) {
 490        if self.source.is_empty() {
 491            return;
 492        }
 493
 494        if self.pending_parse.is_some() {
 495            self.should_reparse = true;
 496            return;
 497        }
 498        self.should_reparse = false;
 499        self.pending_parse = Some(self.start_background_parse(cx));
 500    }
 501
 502    fn start_background_parse(&self, cx: &Context<Self>) -> Task<()> {
 503        let source = self.source.clone();
 504        let should_parse_links_only = self.options.parse_links_only;
 505        let language_registry = self.language_registry.clone();
 506        let fallback = self.fallback_code_block_language.clone();
 507
 508        let parsed = cx.background_spawn(async move {
 509            if should_parse_links_only {
 510                return (
 511                    ParsedMarkdown {
 512                        events: Arc::from(parse_links_only(source.as_ref())),
 513                        source,
 514                        languages_by_name: TreeMap::default(),
 515                        languages_by_path: TreeMap::default(),
 516                    },
 517                    Default::default(),
 518                );
 519            }
 520
 521            let (events, language_names, paths) = parse_markdown(&source);
 522            let mut images_by_source_offset = HashMap::default();
 523            let mut languages_by_name = TreeMap::default();
 524            let mut languages_by_path = TreeMap::default();
 525            if let Some(registry) = language_registry.as_ref() {
 526                for name in language_names {
 527                    let language = if !name.is_empty() {
 528                        registry.language_for_name_or_extension(&name).left_future()
 529                    } else if let Some(fallback) = &fallback {
 530                        registry.language_for_name(fallback.as_ref()).right_future()
 531                    } else {
 532                        continue;
 533                    };
 534                    if let Ok(language) = language.await {
 535                        languages_by_name.insert(name, language);
 536                    }
 537                }
 538
 539                for path in paths {
 540                    if let Ok(language) = registry
 541                        .load_language_for_file_path(Path::new(path.as_ref()))
 542                        .await
 543                    {
 544                        languages_by_path.insert(path, language);
 545                    }
 546                }
 547            }
 548
 549            for (range, event) in &events {
 550                if let MarkdownEvent::Start(MarkdownTag::Image { dest_url, .. }) = event
 551                    && let Some(data_url) = dest_url.strip_prefix("data:")
 552                {
 553                    let Some((mime_info, data)) = data_url.split_once(',') else {
 554                        continue;
 555                    };
 556                    let Some((mime_type, encoding)) = mime_info.split_once(';') else {
 557                        continue;
 558                    };
 559                    let Some(format) = ImageFormat::from_mime_type(mime_type) else {
 560                        continue;
 561                    };
 562                    let is_base64 = encoding == "base64";
 563                    if is_base64
 564                        && let Some(bytes) = base64::prelude::BASE64_STANDARD
 565                            .decode(data)
 566                            .log_with_level(Level::Debug)
 567                    {
 568                        let image = Arc::new(Image::from_bytes(format, bytes));
 569                        images_by_source_offset.insert(range.start, image);
 570                    }
 571                }
 572            }
 573
 574            (
 575                ParsedMarkdown {
 576                    source,
 577                    events: Arc::from(events),
 578                    languages_by_name,
 579                    languages_by_path,
 580                },
 581                images_by_source_offset,
 582            )
 583        });
 584
 585        cx.spawn(async move |this, cx| {
 586            let (parsed, images_by_source_offset) = parsed.await;
 587
 588            this.update(cx, |this, cx| {
 589                this.parsed_markdown = parsed;
 590                this.images_by_source_offset = images_by_source_offset;
 591                this.pending_parse.take();
 592                if this.should_reparse {
 593                    this.parse(cx);
 594                }
 595                cx.refresh_windows();
 596            })
 597            .ok();
 598        })
 599    }
 600}
 601
 602impl Focusable for Markdown {
 603    fn focus_handle(&self, _cx: &App) -> FocusHandle {
 604        self.focus_handle.clone()
 605    }
 606}
 607
 608#[derive(Debug, Default, Clone)]
 609enum SelectMode {
 610    #[default]
 611    Character,
 612    Word(Range<usize>),
 613    Line(Range<usize>),
 614    All,
 615}
 616
 617#[derive(Clone, Default)]
 618struct Selection {
 619    start: usize,
 620    end: usize,
 621    reversed: bool,
 622    pending: bool,
 623    mode: SelectMode,
 624}
 625
 626impl Selection {
 627    fn set_head(&mut self, head: usize, rendered_text: &RenderedText) {
 628        match &self.mode {
 629            SelectMode::Character => {
 630                if head < self.tail() {
 631                    if !self.reversed {
 632                        self.end = self.start;
 633                        self.reversed = true;
 634                    }
 635                    self.start = head;
 636                } else {
 637                    if self.reversed {
 638                        self.start = self.end;
 639                        self.reversed = false;
 640                    }
 641                    self.end = head;
 642                }
 643            }
 644            SelectMode::Word(original_range) | SelectMode::Line(original_range) => {
 645                let head_range = if matches!(self.mode, SelectMode::Word(_)) {
 646                    rendered_text.surrounding_word_range(head)
 647                } else {
 648                    rendered_text.surrounding_line_range(head)
 649                };
 650
 651                if head < original_range.start {
 652                    self.start = head_range.start;
 653                    self.end = original_range.end;
 654                    self.reversed = true;
 655                } else if head >= original_range.end {
 656                    self.start = original_range.start;
 657                    self.end = head_range.end;
 658                    self.reversed = false;
 659                } else {
 660                    self.start = original_range.start;
 661                    self.end = original_range.end;
 662                    self.reversed = false;
 663                }
 664            }
 665            SelectMode::All => {
 666                self.start = 0;
 667                self.end = rendered_text
 668                    .lines
 669                    .last()
 670                    .map(|line| line.source_end)
 671                    .unwrap_or(0);
 672                self.reversed = false;
 673            }
 674        }
 675    }
 676
 677    fn tail(&self) -> usize {
 678        if self.reversed { self.end } else { self.start }
 679    }
 680}
 681
 682#[derive(Debug, Clone, Default)]
 683pub struct ParsedMarkdown {
 684    pub source: SharedString,
 685    pub events: Arc<[(Range<usize>, MarkdownEvent)]>,
 686    pub languages_by_name: TreeMap<SharedString, Arc<Language>>,
 687    pub languages_by_path: TreeMap<Arc<str>, Arc<Language>>,
 688}
 689
 690impl ParsedMarkdown {
 691    pub fn source(&self) -> &SharedString {
 692        &self.source
 693    }
 694
 695    pub fn events(&self) -> &Arc<[(Range<usize>, MarkdownEvent)]> {
 696        &self.events
 697    }
 698}
 699
 700pub struct MarkdownElement {
 701    markdown: Entity<Markdown>,
 702    style: MarkdownStyle,
 703    code_block_renderer: CodeBlockRenderer,
 704    on_url_click: Option<Box<dyn Fn(SharedString, &mut Window, &mut App)>>,
 705}
 706
 707impl MarkdownElement {
 708    pub fn new(markdown: Entity<Markdown>, style: MarkdownStyle) -> Self {
 709        Self {
 710            markdown,
 711            style,
 712            code_block_renderer: CodeBlockRenderer::Default {
 713                copy_button: true,
 714                copy_button_on_hover: false,
 715                border: false,
 716            },
 717            on_url_click: None,
 718        }
 719    }
 720
 721    #[cfg(any(test, feature = "test-support"))]
 722    pub fn rendered_text(
 723        markdown: Entity<Markdown>,
 724        cx: &mut gpui::VisualTestContext,
 725        style: impl FnOnce(&Window, &App) -> MarkdownStyle,
 726    ) -> String {
 727        use gpui::size;
 728
 729        let (text, _) = cx.draw(
 730            Default::default(),
 731            size(px(600.0), px(600.0)),
 732            |window, cx| Self::new(markdown, style(window, cx)),
 733        );
 734        text.text
 735            .lines
 736            .iter()
 737            .map(|line| line.layout.wrapped_text())
 738            .collect::<Vec<_>>()
 739            .join("\n")
 740    }
 741
 742    pub fn code_block_renderer(mut self, variant: CodeBlockRenderer) -> Self {
 743        self.code_block_renderer = variant;
 744        self
 745    }
 746
 747    pub fn on_url_click(
 748        mut self,
 749        handler: impl Fn(SharedString, &mut Window, &mut App) + 'static,
 750    ) -> Self {
 751        self.on_url_click = Some(Box::new(handler));
 752        self
 753    }
 754
 755    fn paint_selection(
 756        &self,
 757        bounds: Bounds<Pixels>,
 758        rendered_text: &RenderedText,
 759        window: &mut Window,
 760        cx: &mut App,
 761    ) {
 762        let selection = self.markdown.read(cx).selection.clone();
 763        let selection_start = rendered_text.position_for_source_index(selection.start);
 764        let selection_end = rendered_text.position_for_source_index(selection.end);
 765        if let Some(((start_position, start_line_height), (end_position, end_line_height))) =
 766            selection_start.zip(selection_end)
 767        {
 768            if start_position.y == end_position.y {
 769                window.paint_quad(quad(
 770                    Bounds::from_corners(
 771                        start_position,
 772                        point(end_position.x, end_position.y + end_line_height),
 773                    ),
 774                    Pixels::ZERO,
 775                    self.style.selection_background_color,
 776                    Edges::default(),
 777                    Hsla::transparent_black(),
 778                    BorderStyle::default(),
 779                ));
 780            } else {
 781                window.paint_quad(quad(
 782                    Bounds::from_corners(
 783                        start_position,
 784                        point(bounds.right(), start_position.y + start_line_height),
 785                    ),
 786                    Pixels::ZERO,
 787                    self.style.selection_background_color,
 788                    Edges::default(),
 789                    Hsla::transparent_black(),
 790                    BorderStyle::default(),
 791                ));
 792
 793                if end_position.y > start_position.y + start_line_height {
 794                    window.paint_quad(quad(
 795                        Bounds::from_corners(
 796                            point(bounds.left(), start_position.y + start_line_height),
 797                            point(bounds.right(), end_position.y),
 798                        ),
 799                        Pixels::ZERO,
 800                        self.style.selection_background_color,
 801                        Edges::default(),
 802                        Hsla::transparent_black(),
 803                        BorderStyle::default(),
 804                    ));
 805                }
 806
 807                window.paint_quad(quad(
 808                    Bounds::from_corners(
 809                        point(bounds.left(), end_position.y),
 810                        point(end_position.x, end_position.y + end_line_height),
 811                    ),
 812                    Pixels::ZERO,
 813                    self.style.selection_background_color,
 814                    Edges::default(),
 815                    Hsla::transparent_black(),
 816                    BorderStyle::default(),
 817                ));
 818            }
 819        }
 820    }
 821
 822    fn paint_mouse_listeners(
 823        &mut self,
 824        hitbox: &Hitbox,
 825        rendered_text: &RenderedText,
 826        window: &mut Window,
 827        cx: &mut App,
 828    ) {
 829        if self.style.prevent_mouse_interaction {
 830            return;
 831        }
 832
 833        let is_hovering_link = hitbox.is_hovered(window)
 834            && !self.markdown.read(cx).selection.pending
 835            && rendered_text
 836                .link_for_position(window.mouse_position())
 837                .is_some();
 838
 839        if !self.style.prevent_mouse_interaction {
 840            if is_hovering_link {
 841                window.set_cursor_style(CursorStyle::PointingHand, hitbox);
 842            } else {
 843                window.set_cursor_style(CursorStyle::IBeam, hitbox);
 844            }
 845        }
 846
 847        let on_open_url = self.on_url_click.take();
 848
 849        self.on_mouse_event(window, cx, {
 850            let hitbox = hitbox.clone();
 851            move |markdown, event: &MouseDownEvent, phase, window, _| {
 852                if phase.capture()
 853                    && event.button == MouseButton::Right
 854                    && hitbox.is_hovered(window)
 855                {
 856                    // Capture selected text so it survives until menu item is clicked
 857                    markdown.capture_selection_for_context_menu();
 858                }
 859            }
 860        });
 861
 862        self.on_mouse_event(window, cx, {
 863            let rendered_text = rendered_text.clone();
 864            let hitbox = hitbox.clone();
 865            move |markdown, event: &MouseDownEvent, phase, window, cx| {
 866                if hitbox.is_hovered(window) {
 867                    if phase.bubble() {
 868                        if let Some(link) = rendered_text.link_for_position(event.position) {
 869                            markdown.pressed_link = Some(link.clone());
 870                        } else {
 871                            let source_index =
 872                                match rendered_text.source_index_for_position(event.position) {
 873                                    Ok(ix) | Err(ix) => ix,
 874                                };
 875                            let (range, mode) = match event.click_count {
 876                                1 => {
 877                                    let range = source_index..source_index;
 878                                    (range, SelectMode::Character)
 879                                }
 880                                2 => {
 881                                    let range = rendered_text.surrounding_word_range(source_index);
 882                                    (range.clone(), SelectMode::Word(range))
 883                                }
 884                                3 => {
 885                                    let range = rendered_text.surrounding_line_range(source_index);
 886                                    (range.clone(), SelectMode::Line(range))
 887                                }
 888                                _ => {
 889                                    let range = 0..rendered_text
 890                                        .lines
 891                                        .last()
 892                                        .map(|line| line.source_end)
 893                                        .unwrap_or(0);
 894                                    (range, SelectMode::All)
 895                                }
 896                            };
 897                            markdown.selection = Selection {
 898                                start: range.start,
 899                                end: range.end,
 900                                reversed: false,
 901                                pending: true,
 902                                mode,
 903                            };
 904                            window.focus(&markdown.focus_handle, cx);
 905                        }
 906
 907                        window.prevent_default();
 908                        cx.notify();
 909                    }
 910                } else if phase.capture() && event.button == MouseButton::Left {
 911                    markdown.selection = Selection::default();
 912                    markdown.pressed_link = None;
 913                    cx.notify();
 914                }
 915            }
 916        });
 917        self.on_mouse_event(window, cx, {
 918            let rendered_text = rendered_text.clone();
 919            let hitbox = hitbox.clone();
 920            let was_hovering_link = is_hovering_link;
 921            move |markdown, event: &MouseMoveEvent, phase, window, cx| {
 922                if phase.capture() {
 923                    return;
 924                }
 925
 926                if markdown.selection.pending {
 927                    let source_index = match rendered_text.source_index_for_position(event.position)
 928                    {
 929                        Ok(ix) | Err(ix) => ix,
 930                    };
 931                    markdown.selection.set_head(source_index, &rendered_text);
 932                    markdown.autoscroll_code_block(source_index, event.position);
 933                    markdown.autoscroll_request = Some(source_index);
 934                    cx.notify();
 935                } else {
 936                    let is_hovering_link = hitbox.is_hovered(window)
 937                        && rendered_text.link_for_position(event.position).is_some();
 938                    if is_hovering_link != was_hovering_link {
 939                        cx.notify();
 940                    }
 941                }
 942            }
 943        });
 944        self.on_mouse_event(window, cx, {
 945            let rendered_text = rendered_text.clone();
 946            move |markdown, event: &MouseUpEvent, phase, window, cx| {
 947                if phase.bubble() {
 948                    if let Some(pressed_link) = markdown.pressed_link.take()
 949                        && Some(&pressed_link) == rendered_text.link_for_position(event.position)
 950                    {
 951                        if let Some(open_url) = on_open_url.as_ref() {
 952                            open_url(pressed_link.destination_url, window, cx);
 953                        } else {
 954                            cx.open_url(&pressed_link.destination_url);
 955                        }
 956                    }
 957                } else if markdown.selection.pending {
 958                    markdown.selection.pending = false;
 959                    #[cfg(any(target_os = "linux", target_os = "freebsd"))]
 960                    {
 961                        let text = rendered_text
 962                            .text_for_range(markdown.selection.start..markdown.selection.end);
 963                        cx.write_to_primary(ClipboardItem::new_string(text))
 964                    }
 965                    cx.notify();
 966                }
 967            }
 968        });
 969    }
 970
 971    fn autoscroll(
 972        &self,
 973        rendered_text: &RenderedText,
 974        window: &mut Window,
 975        cx: &mut App,
 976    ) -> Option<()> {
 977        let autoscroll_index = self
 978            .markdown
 979            .update(cx, |markdown, _| markdown.autoscroll_request.take())?;
 980        let (position, line_height) = rendered_text.position_for_source_index(autoscroll_index)?;
 981
 982        let text_style = self.style.base_text_style.clone();
 983        let font_id = window.text_system().resolve_font(&text_style.font());
 984        let font_size = text_style.font_size.to_pixels(window.rem_size());
 985        let em_width = window.text_system().em_width(font_id, font_size).unwrap();
 986        window.request_autoscroll(Bounds::from_corners(
 987            point(position.x - 3. * em_width, position.y - 3. * line_height),
 988            point(position.x + 3. * em_width, position.y + 3. * line_height),
 989        ));
 990        Some(())
 991    }
 992
 993    fn on_mouse_event<T: MouseEvent>(
 994        &self,
 995        window: &mut Window,
 996        _cx: &mut App,
 997        mut f: impl 'static
 998        + FnMut(&mut Markdown, &T, DispatchPhase, &mut Window, &mut Context<Markdown>),
 999    ) {
1000        window.on_mouse_event({
1001            let markdown = self.markdown.downgrade();
1002            move |event, phase, window, cx| {
1003                markdown
1004                    .update(cx, |markdown, cx| f(markdown, event, phase, window, cx))
1005                    .log_err();
1006            }
1007        });
1008    }
1009}
1010
1011impl Styled for MarkdownElement {
1012    fn style(&mut self) -> &mut StyleRefinement {
1013        &mut self.style.container_style
1014    }
1015}
1016
1017impl Element for MarkdownElement {
1018    type RequestLayoutState = RenderedMarkdown;
1019    type PrepaintState = Hitbox;
1020
1021    fn id(&self) -> Option<ElementId> {
1022        None
1023    }
1024
1025    fn source_location(&self) -> Option<&'static core::panic::Location<'static>> {
1026        None
1027    }
1028
1029    fn request_layout(
1030        &mut self,
1031        _id: Option<&GlobalElementId>,
1032        _inspector_id: Option<&gpui::InspectorElementId>,
1033        window: &mut Window,
1034        cx: &mut App,
1035    ) -> (gpui::LayoutId, Self::RequestLayoutState) {
1036        let mut builder = MarkdownElementBuilder::new(
1037            &self.style.container_style,
1038            self.style.base_text_style.clone(),
1039            self.style.syntax.clone(),
1040        );
1041        let (parsed_markdown, images) = {
1042            let markdown = self.markdown.read(cx);
1043            (
1044                markdown.parsed_markdown.clone(),
1045                markdown.images_by_source_offset.clone(),
1046            )
1047        };
1048        let markdown_end = if let Some(last) = parsed_markdown.events.last() {
1049            last.0.end
1050        } else {
1051            0
1052        };
1053        let mut code_block_ids = HashSet::default();
1054
1055        let mut current_img_block_range: Option<Range<usize>> = None;
1056        for (index, (range, event)) in parsed_markdown.events.iter().enumerate() {
1057            // Skip alt text for images that rendered
1058            if let Some(current_img_block_range) = &current_img_block_range
1059                && current_img_block_range.end > range.end
1060            {
1061                continue;
1062            }
1063
1064            match event {
1065                MarkdownEvent::Start(tag) => {
1066                    match tag {
1067                        MarkdownTag::Image { .. } => {
1068                            if let Some(image) = images.get(&range.start) {
1069                                current_img_block_range = Some(range.clone());
1070                                builder.modify_current_div(|el| {
1071                                    el.items_center()
1072                                        .flex()
1073                                        .flex_row()
1074                                        .child(img(image.clone()))
1075                                });
1076                            }
1077                        }
1078                        MarkdownTag::Paragraph => {
1079                            builder.push_div(
1080                                div().when(!self.style.height_is_multiple_of_line_height, |el| {
1081                                    el.mb_2().line_height(rems(1.3))
1082                                }),
1083                                range,
1084                                markdown_end,
1085                            );
1086                        }
1087                        MarkdownTag::Heading { level, .. } => {
1088                            let mut heading = div().mb_2();
1089
1090                            heading = apply_heading_style(
1091                                heading,
1092                                *level,
1093                                self.style.heading_level_styles.as_ref(),
1094                            );
1095
1096                            heading.style().refine(&self.style.heading);
1097
1098                            let text_style = self.style.heading.text_style().clone();
1099
1100                            builder.push_text_style(text_style);
1101                            builder.push_div(heading, range, markdown_end);
1102                        }
1103                        MarkdownTag::BlockQuote => {
1104                            builder.push_text_style(self.style.block_quote.clone());
1105                            builder.push_div(
1106                                div()
1107                                    .pl_4()
1108                                    .mb_2()
1109                                    .border_l_4()
1110                                    .border_color(self.style.block_quote_border_color),
1111                                range,
1112                                markdown_end,
1113                            );
1114                        }
1115                        MarkdownTag::CodeBlock { kind, .. } => {
1116                            let language = match kind {
1117                                CodeBlockKind::Fenced => None,
1118                                CodeBlockKind::FencedLang(language) => {
1119                                    parsed_markdown.languages_by_name.get(language).cloned()
1120                                }
1121                                CodeBlockKind::FencedSrc(path_range) => parsed_markdown
1122                                    .languages_by_path
1123                                    .get(&path_range.path)
1124                                    .cloned(),
1125                                _ => None,
1126                            };
1127
1128                            let is_indented = matches!(kind, CodeBlockKind::Indented);
1129                            let scroll_handle = if self.style.code_block_overflow_x_scroll {
1130                                code_block_ids.insert(range.start);
1131                                Some(self.markdown.update(cx, |markdown, _| {
1132                                    markdown.code_block_scroll_handle(range.start)
1133                                }))
1134                            } else {
1135                                None
1136                            };
1137
1138                            match (&self.code_block_renderer, is_indented) {
1139                                (CodeBlockRenderer::Default { .. }, _) | (_, true) => {
1140                                    // This is a parent container that we can position the copy button inside.
1141                                    let parent_container =
1142                                        div().group("code_block").relative().w_full();
1143
1144                                    let mut parent_container: AnyDiv = if let Some(scroll_handle) =
1145                                        scroll_handle.as_ref()
1146                                    {
1147                                        let scrollbars = Scrollbars::new(ScrollAxes::Horizontal)
1148                                            .id(("markdown-code-block-scrollbar", range.start))
1149                                            .tracked_scroll_handle(scroll_handle)
1150                                            .with_track_along(
1151                                                ScrollAxes::Horizontal,
1152                                                cx.theme().colors().editor_background,
1153                                            )
1154                                            .notify_content();
1155
1156                                        parent_container
1157                                            .rounded_lg()
1158                                            .custom_scrollbars(scrollbars, window, cx)
1159                                            .into()
1160                                    } else {
1161                                        parent_container.into()
1162                                    };
1163
1164                                    if let CodeBlockRenderer::Default { border: true, .. } =
1165                                        &self.code_block_renderer
1166                                    {
1167                                        parent_container = parent_container
1168                                            .rounded_md()
1169                                            .border_1()
1170                                            .border_color(cx.theme().colors().border_variant);
1171                                    }
1172
1173                                    parent_container.style().refine(&self.style.code_block);
1174                                    builder.push_div(parent_container, range, markdown_end);
1175
1176                                    let code_block = div()
1177                                        .id(("code-block", range.start))
1178                                        .rounded_lg()
1179                                        .map(|mut code_block| {
1180                                            if let Some(scroll_handle) = scroll_handle.as_ref() {
1181                                                code_block.style().restrict_scroll_to_axis =
1182                                                    Some(true);
1183                                                code_block
1184                                                    .flex()
1185                                                    .overflow_x_scroll()
1186                                                    .track_scroll(scroll_handle)
1187                                            } else {
1188                                                code_block.w_full()
1189                                            }
1190                                        });
1191
1192                                    builder.push_text_style(self.style.code_block.text.to_owned());
1193                                    builder.push_code_block(language);
1194                                    builder.push_div(code_block, range, markdown_end);
1195                                }
1196                                (CodeBlockRenderer::Custom { .. }, _) => {}
1197                            }
1198                        }
1199                        MarkdownTag::HtmlBlock => builder.push_div(div(), range, markdown_end),
1200                        MarkdownTag::List(bullet_index) => {
1201                            builder.push_list(*bullet_index);
1202                            builder.push_div(div().pl_2p5(), range, markdown_end);
1203                        }
1204                        MarkdownTag::Item => {
1205                            let bullet = if let Some((_, MarkdownEvent::TaskListMarker(checked))) =
1206                                parsed_markdown.events.get(index.saturating_add(1))
1207                            {
1208                                let source = &parsed_markdown.source()[range.clone()];
1209
1210                                Checkbox::new(
1211                                    ElementId::Name(source.to_string().into()),
1212                                    if *checked {
1213                                        ToggleState::Selected
1214                                    } else {
1215                                        ToggleState::Unselected
1216                                    },
1217                                )
1218                                .fill()
1219                                .visualization_only(true)
1220                                .into_any_element()
1221                            } else if let Some(bullet_index) = builder.next_bullet_index() {
1222                                div().child(format!("{}.", bullet_index)).into_any_element()
1223                            } else {
1224                                div().child("").into_any_element()
1225                            };
1226                            builder.push_div(
1227                                div()
1228                                    .when(!self.style.height_is_multiple_of_line_height, |el| {
1229                                        el.mb_1().gap_1().line_height(rems(1.3))
1230                                    })
1231                                    .h_flex()
1232                                    .items_start()
1233                                    .child(bullet),
1234                                range,
1235                                markdown_end,
1236                            );
1237                            // Without `w_0`, text doesn't wrap to the width of the container.
1238                            builder.push_div(div().flex_1().w_0(), range, markdown_end);
1239                        }
1240                        MarkdownTag::Emphasis => builder.push_text_style(TextStyleRefinement {
1241                            font_style: Some(FontStyle::Italic),
1242                            ..Default::default()
1243                        }),
1244                        MarkdownTag::Strong => builder.push_text_style(TextStyleRefinement {
1245                            font_weight: Some(FontWeight::BOLD),
1246                            ..Default::default()
1247                        }),
1248                        MarkdownTag::Strikethrough => {
1249                            builder.push_text_style(TextStyleRefinement {
1250                                strikethrough: Some(StrikethroughStyle {
1251                                    thickness: px(1.),
1252                                    color: None,
1253                                }),
1254                                ..Default::default()
1255                            })
1256                        }
1257                        MarkdownTag::Link { dest_url, .. } => {
1258                            if builder.code_block_stack.is_empty() {
1259                                builder.push_link(dest_url.clone(), range.clone());
1260                                let style = self
1261                                    .style
1262                                    .link_callback
1263                                    .as_ref()
1264                                    .and_then(|callback| callback(dest_url, cx))
1265                                    .unwrap_or_else(|| self.style.link.clone());
1266                                builder.push_text_style(style)
1267                            }
1268                        }
1269                        MarkdownTag::MetadataBlock(_) => {}
1270                        MarkdownTag::Table(alignments) => {
1271                            builder.table.start(alignments.clone());
1272
1273                            let column_count = alignments.len();
1274                            builder.push_div(
1275                                div()
1276                                    .id(("table", range.start))
1277                                    .grid()
1278                                    .grid_cols(column_count as u16)
1279                                    .when(self.style.table_columns_min_size, |this| {
1280                                        this.grid_cols_min_content(column_count as u16)
1281                                    })
1282                                    .when(!self.style.table_columns_min_size, |this| {
1283                                        this.grid_cols(column_count as u16)
1284                                    })
1285                                    .w_full()
1286                                    .mb_2()
1287                                    .border(px(1.5))
1288                                    .border_color(cx.theme().colors().border)
1289                                    .rounded_sm()
1290                                    .overflow_hidden(),
1291                                range,
1292                                markdown_end,
1293                            );
1294                        }
1295                        MarkdownTag::TableHead => {
1296                            builder.table.start_head();
1297                            builder.push_text_style(TextStyleRefinement {
1298                                font_weight: Some(FontWeight::SEMIBOLD),
1299                                ..Default::default()
1300                            });
1301                        }
1302                        MarkdownTag::TableRow => {
1303                            builder.table.start_row();
1304                        }
1305                        MarkdownTag::TableCell => {
1306                            let is_header = builder.table.in_head;
1307                            let row_index = builder.table.row_index;
1308                            let col_index = builder.table.col_index;
1309
1310                            builder.push_div(
1311                                div()
1312                                    .when(col_index > 0, |this| this.border_l_1())
1313                                    .when(row_index > 0, |this| this.border_t_1())
1314                                    .border_color(cx.theme().colors().border)
1315                                    .px_1()
1316                                    .py_0p5()
1317                                    .when(is_header, |this| {
1318                                        this.bg(cx.theme().colors().title_bar_background)
1319                                    })
1320                                    .when(!is_header && row_index % 2 == 1, |this| {
1321                                        this.bg(cx.theme().colors().panel_background)
1322                                    }),
1323                                range,
1324                                markdown_end,
1325                            );
1326                        }
1327                        _ => log::debug!("unsupported markdown tag {:?}", tag),
1328                    }
1329                }
1330                MarkdownEvent::End(tag) => match tag {
1331                    MarkdownTagEnd::Image => {
1332                        current_img_block_range.take();
1333                    }
1334                    MarkdownTagEnd::Paragraph => {
1335                        builder.pop_div();
1336                    }
1337                    MarkdownTagEnd::Heading(_) => {
1338                        builder.pop_div();
1339                        builder.pop_text_style()
1340                    }
1341                    MarkdownTagEnd::BlockQuote(_kind) => {
1342                        builder.pop_text_style();
1343                        builder.pop_div()
1344                    }
1345                    MarkdownTagEnd::CodeBlock => {
1346                        builder.trim_trailing_newline();
1347
1348                        builder.pop_div();
1349                        builder.pop_code_block();
1350                        builder.pop_text_style();
1351
1352                        if let CodeBlockRenderer::Default {
1353                            copy_button: true, ..
1354                        } = &self.code_block_renderer
1355                        {
1356                            builder.modify_current_div(|el| {
1357                                let content_range = parser::extract_code_block_content_range(
1358                                    &parsed_markdown.source()[range.clone()],
1359                                );
1360                                let content_range = content_range.start + range.start
1361                                    ..content_range.end + range.start;
1362
1363                                let code = parsed_markdown.source()[content_range].to_string();
1364                                let codeblock = render_copy_code_block_button(
1365                                    range.end,
1366                                    code,
1367                                    self.markdown.clone(),
1368                                );
1369                                el.child(
1370                                    h_flex()
1371                                        .w_4()
1372                                        .absolute()
1373                                        .top_1p5()
1374                                        .right_1p5()
1375                                        .justify_end()
1376                                        .child(codeblock),
1377                                )
1378                            });
1379                        }
1380
1381                        if let CodeBlockRenderer::Default {
1382                            copy_button_on_hover: true,
1383                            ..
1384                        } = &self.code_block_renderer
1385                        {
1386                            builder.modify_current_div(|el| {
1387                                let content_range = parser::extract_code_block_content_range(
1388                                    &parsed_markdown.source()[range.clone()],
1389                                );
1390                                let content_range = content_range.start + range.start
1391                                    ..content_range.end + range.start;
1392
1393                                let code = parsed_markdown.source()[content_range].to_string();
1394                                let codeblock = render_copy_code_block_button(
1395                                    range.end,
1396                                    code,
1397                                    self.markdown.clone(),
1398                                );
1399                                el.child(
1400                                    h_flex()
1401                                        .w_4()
1402                                        .absolute()
1403                                        .top_0()
1404                                        .right_0()
1405                                        .justify_end()
1406                                        .visible_on_hover("code_block")
1407                                        .child(codeblock),
1408                                )
1409                            });
1410                        }
1411
1412                        // Pop the parent container.
1413                        builder.pop_div();
1414                    }
1415                    MarkdownTagEnd::HtmlBlock => builder.pop_div(),
1416                    MarkdownTagEnd::List(_) => {
1417                        builder.pop_list();
1418                        builder.pop_div();
1419                    }
1420                    MarkdownTagEnd::Item => {
1421                        builder.pop_div();
1422                        builder.pop_div();
1423                    }
1424                    MarkdownTagEnd::Emphasis => builder.pop_text_style(),
1425                    MarkdownTagEnd::Strong => builder.pop_text_style(),
1426                    MarkdownTagEnd::Strikethrough => builder.pop_text_style(),
1427                    MarkdownTagEnd::Link => {
1428                        if builder.code_block_stack.is_empty() {
1429                            builder.pop_text_style()
1430                        }
1431                    }
1432                    MarkdownTagEnd::Table => {
1433                        builder.pop_div();
1434                        builder.table.end();
1435                    }
1436                    MarkdownTagEnd::TableHead => {
1437                        builder.pop_text_style();
1438                        builder.table.end_head();
1439                    }
1440                    MarkdownTagEnd::TableRow => {
1441                        builder.table.end_row();
1442                    }
1443                    MarkdownTagEnd::TableCell => {
1444                        builder.pop_div();
1445                        builder.table.end_cell();
1446                    }
1447                    _ => log::debug!("unsupported markdown tag end: {:?}", tag),
1448                },
1449                MarkdownEvent::Text => {
1450                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1451                }
1452                MarkdownEvent::SubstitutedText(text) => {
1453                    builder.push_text(text, range.clone());
1454                }
1455                MarkdownEvent::Code => {
1456                    builder.push_text_style(self.style.inline_code.clone());
1457                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1458                    builder.pop_text_style();
1459                }
1460                MarkdownEvent::Html => {
1461                    let html = &parsed_markdown.source[range.clone()];
1462                    if html.starts_with("<!--") {
1463                        builder.html_comment = true;
1464                    }
1465                    if html.trim_end().ends_with("-->") {
1466                        builder.html_comment = false;
1467                        continue;
1468                    }
1469                    if builder.html_comment {
1470                        continue;
1471                    }
1472                    builder.push_text(html, range.clone());
1473                }
1474                MarkdownEvent::InlineHtml => {
1475                    let html = &parsed_markdown.source[range.clone()];
1476                    if html.starts_with("<code>") {
1477                        builder.push_text_style(self.style.inline_code.clone());
1478                        continue;
1479                    }
1480                    if html.trim_end().starts_with("</code>") {
1481                        builder.pop_text_style();
1482                        continue;
1483                    }
1484                    builder.push_text(&parsed_markdown.source[range.clone()], range.clone());
1485                }
1486                MarkdownEvent::Rule => {
1487                    builder.push_div(
1488                        div()
1489                            .border_b_1()
1490                            .my_2()
1491                            .border_color(self.style.rule_color),
1492                        range,
1493                        markdown_end,
1494                    );
1495                    builder.pop_div()
1496                }
1497                MarkdownEvent::SoftBreak => builder.push_text(" ", range.clone()),
1498                MarkdownEvent::HardBreak => builder.push_text("\n", range.clone()),
1499                MarkdownEvent::TaskListMarker(_) => {
1500                    // handled inside the `MarkdownTag::Item` case
1501                }
1502                _ => log::debug!("unsupported markdown event {:?}", event),
1503            }
1504        }
1505        if self.style.code_block_overflow_x_scroll {
1506            let code_block_ids = code_block_ids;
1507            self.markdown.update(cx, move |markdown, _| {
1508                markdown.retain_code_block_scroll_handles(&code_block_ids);
1509            });
1510        } else {
1511            self.markdown
1512                .update(cx, |markdown, _| markdown.clear_code_block_scroll_handles());
1513        }
1514        let mut rendered_markdown = builder.build();
1515        let child_layout_id = rendered_markdown.element.request_layout(window, cx);
1516        let layout_id = window.request_layout(gpui::Style::default(), [child_layout_id], cx);
1517        (layout_id, rendered_markdown)
1518    }
1519
1520    fn prepaint(
1521        &mut self,
1522        _id: Option<&GlobalElementId>,
1523        _inspector_id: Option<&gpui::InspectorElementId>,
1524        bounds: Bounds<Pixels>,
1525        rendered_markdown: &mut Self::RequestLayoutState,
1526        window: &mut Window,
1527        cx: &mut App,
1528    ) -> Self::PrepaintState {
1529        let focus_handle = self.markdown.read(cx).focus_handle.clone();
1530        window.set_focus_handle(&focus_handle, cx);
1531        window.set_view_id(self.markdown.entity_id());
1532
1533        let hitbox = window.insert_hitbox(bounds, HitboxBehavior::Normal);
1534        rendered_markdown.element.prepaint(window, cx);
1535        self.autoscroll(&rendered_markdown.text, window, cx);
1536        hitbox
1537    }
1538
1539    fn paint(
1540        &mut self,
1541        _id: Option<&GlobalElementId>,
1542        _inspector_id: Option<&gpui::InspectorElementId>,
1543        bounds: Bounds<Pixels>,
1544        rendered_markdown: &mut Self::RequestLayoutState,
1545        hitbox: &mut Self::PrepaintState,
1546        window: &mut Window,
1547        cx: &mut App,
1548    ) {
1549        let mut context = KeyContext::default();
1550        context.add("Markdown");
1551        window.set_key_context(context);
1552        window.on_action(std::any::TypeId::of::<crate::Copy>(), {
1553            let entity = self.markdown.clone();
1554            let text = rendered_markdown.text.clone();
1555            move |_, phase, window, cx| {
1556                let text = text.clone();
1557                if phase == DispatchPhase::Bubble {
1558                    entity.update(cx, move |this, cx| this.copy(&text, window, cx))
1559                }
1560            }
1561        });
1562        window.on_action(std::any::TypeId::of::<crate::CopyAsMarkdown>(), {
1563            let entity = self.markdown.clone();
1564            move |_, phase, window, cx| {
1565                if phase == DispatchPhase::Bubble {
1566                    entity.update(cx, move |this, cx| this.copy_as_markdown(window, cx))
1567                }
1568            }
1569        });
1570
1571        self.paint_mouse_listeners(hitbox, &rendered_markdown.text, window, cx);
1572        rendered_markdown.element.paint(window, cx);
1573        self.paint_selection(bounds, &rendered_markdown.text, window, cx);
1574    }
1575}
1576
1577fn apply_heading_style(
1578    mut heading: Div,
1579    level: pulldown_cmark::HeadingLevel,
1580    custom_styles: Option<&HeadingLevelStyles>,
1581) -> Div {
1582    heading = match level {
1583        pulldown_cmark::HeadingLevel::H1 => heading.text_3xl(),
1584        pulldown_cmark::HeadingLevel::H2 => heading.text_2xl(),
1585        pulldown_cmark::HeadingLevel::H3 => heading.text_xl(),
1586        pulldown_cmark::HeadingLevel::H4 => heading.text_lg(),
1587        pulldown_cmark::HeadingLevel::H5 => heading.text_base(),
1588        pulldown_cmark::HeadingLevel::H6 => heading.text_sm(),
1589    };
1590
1591    if let Some(styles) = custom_styles {
1592        let style_opt = match level {
1593            pulldown_cmark::HeadingLevel::H1 => &styles.h1,
1594            pulldown_cmark::HeadingLevel::H2 => &styles.h2,
1595            pulldown_cmark::HeadingLevel::H3 => &styles.h3,
1596            pulldown_cmark::HeadingLevel::H4 => &styles.h4,
1597            pulldown_cmark::HeadingLevel::H5 => &styles.h5,
1598            pulldown_cmark::HeadingLevel::H6 => &styles.h6,
1599        };
1600
1601        if let Some(style) = style_opt {
1602            heading.style().text = style.clone();
1603        }
1604    }
1605
1606    heading
1607}
1608
1609fn render_copy_code_block_button(
1610    id: usize,
1611    code: String,
1612    markdown: Entity<Markdown>,
1613) -> impl IntoElement {
1614    let id = ElementId::named_usize("copy-markdown-code", id);
1615
1616    CopyButton::new(id.clone(), code.clone()).custom_on_click({
1617        let markdown = markdown;
1618        move |_window, cx| {
1619            let id = id.clone();
1620            markdown.update(cx, |this, cx| {
1621                this.copied_code_blocks.insert(id.clone());
1622
1623                cx.write_to_clipboard(ClipboardItem::new_string(code.clone()));
1624
1625                cx.spawn(async move |this, cx| {
1626                    cx.background_executor().timer(Duration::from_secs(2)).await;
1627
1628                    cx.update(|cx| {
1629                        this.update(cx, |this, cx| {
1630                            this.copied_code_blocks.remove(&id);
1631                            cx.notify();
1632                        })
1633                    })
1634                    .ok();
1635                })
1636                .detach();
1637            });
1638        }
1639    })
1640}
1641
1642impl IntoElement for MarkdownElement {
1643    type Element = Self;
1644
1645    fn into_element(self) -> Self::Element {
1646        self
1647    }
1648}
1649
1650pub enum AnyDiv {
1651    Div(Div),
1652    Stateful(Stateful<Div>),
1653}
1654
1655impl AnyDiv {
1656    fn into_any_element(self) -> AnyElement {
1657        match self {
1658            Self::Div(div) => div.into_any_element(),
1659            Self::Stateful(div) => div.into_any_element(),
1660        }
1661    }
1662}
1663
1664impl From<Div> for AnyDiv {
1665    fn from(value: Div) -> Self {
1666        Self::Div(value)
1667    }
1668}
1669
1670impl From<Stateful<Div>> for AnyDiv {
1671    fn from(value: Stateful<Div>) -> Self {
1672        Self::Stateful(value)
1673    }
1674}
1675
1676impl Styled for AnyDiv {
1677    fn style(&mut self) -> &mut StyleRefinement {
1678        match self {
1679            Self::Div(div) => div.style(),
1680            Self::Stateful(div) => div.style(),
1681        }
1682    }
1683}
1684
1685impl ParentElement for AnyDiv {
1686    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
1687        match self {
1688            Self::Div(div) => div.extend(elements),
1689            Self::Stateful(div) => div.extend(elements),
1690        }
1691    }
1692}
1693
1694#[derive(Default)]
1695struct TableState {
1696    alignments: Vec<Alignment>,
1697    in_head: bool,
1698    row_index: usize,
1699    col_index: usize,
1700}
1701
1702impl TableState {
1703    fn start(&mut self, alignments: Vec<Alignment>) {
1704        self.alignments = alignments;
1705        self.in_head = false;
1706        self.row_index = 0;
1707        self.col_index = 0;
1708    }
1709
1710    fn end(&mut self) {
1711        self.alignments.clear();
1712        self.in_head = false;
1713        self.row_index = 0;
1714        self.col_index = 0;
1715    }
1716
1717    fn start_head(&mut self) {
1718        self.in_head = true;
1719    }
1720
1721    fn end_head(&mut self) {
1722        self.in_head = false;
1723    }
1724
1725    fn start_row(&mut self) {
1726        self.col_index = 0;
1727    }
1728
1729    fn end_row(&mut self) {
1730        self.row_index += 1;
1731    }
1732
1733    fn end_cell(&mut self) {
1734        self.col_index += 1;
1735    }
1736}
1737
1738struct MarkdownElementBuilder {
1739    div_stack: Vec<AnyDiv>,
1740    rendered_lines: Vec<RenderedLine>,
1741    pending_line: PendingLine,
1742    rendered_links: Vec<RenderedLink>,
1743    current_source_index: usize,
1744    html_comment: bool,
1745    base_text_style: TextStyle,
1746    text_style_stack: Vec<TextStyleRefinement>,
1747    code_block_stack: Vec<Option<Arc<Language>>>,
1748    list_stack: Vec<ListStackEntry>,
1749    table: TableState,
1750    syntax_theme: Arc<SyntaxTheme>,
1751}
1752
1753#[derive(Default)]
1754struct PendingLine {
1755    text: String,
1756    runs: Vec<TextRun>,
1757    source_mappings: Vec<SourceMapping>,
1758}
1759
1760struct ListStackEntry {
1761    bullet_index: Option<u64>,
1762}
1763
1764impl MarkdownElementBuilder {
1765    fn new(
1766        container_style: &StyleRefinement,
1767        base_text_style: TextStyle,
1768        syntax_theme: Arc<SyntaxTheme>,
1769    ) -> Self {
1770        Self {
1771            div_stack: vec![{
1772                let mut base_div = div();
1773                base_div.style().refine(container_style);
1774                base_div.debug_selector(|| "inner".into()).into()
1775            }],
1776            rendered_lines: Vec::new(),
1777            pending_line: PendingLine::default(),
1778            rendered_links: Vec::new(),
1779            current_source_index: 0,
1780            html_comment: false,
1781            base_text_style,
1782            text_style_stack: Vec::new(),
1783            code_block_stack: Vec::new(),
1784            list_stack: Vec::new(),
1785            table: TableState::default(),
1786            syntax_theme,
1787        }
1788    }
1789
1790    fn push_text_style(&mut self, style: TextStyleRefinement) {
1791        self.text_style_stack.push(style);
1792    }
1793
1794    fn text_style(&self) -> TextStyle {
1795        let mut style = self.base_text_style.clone();
1796        for refinement in &self.text_style_stack {
1797            style.refine(refinement);
1798        }
1799        style
1800    }
1801
1802    fn pop_text_style(&mut self) {
1803        self.text_style_stack.pop();
1804    }
1805
1806    fn push_div(&mut self, div: impl Into<AnyDiv>, range: &Range<usize>, markdown_end: usize) {
1807        let mut div = div.into();
1808        self.flush_text();
1809
1810        if range.start == 0 {
1811            // Remove the top margin on the first element.
1812            div.style().refine(&StyleRefinement {
1813                margin: gpui::EdgesRefinement {
1814                    top: Some(Length::Definite(px(0.).into())),
1815                    left: None,
1816                    right: None,
1817                    bottom: None,
1818                },
1819                ..Default::default()
1820            });
1821        }
1822
1823        if range.end == markdown_end {
1824            div.style().refine(&StyleRefinement {
1825                margin: gpui::EdgesRefinement {
1826                    top: None,
1827                    left: None,
1828                    right: None,
1829                    bottom: Some(Length::Definite(rems(0.).into())),
1830                },
1831                ..Default::default()
1832            });
1833        }
1834
1835        self.div_stack.push(div);
1836    }
1837
1838    fn modify_current_div(&mut self, f: impl FnOnce(AnyDiv) -> AnyDiv) {
1839        self.flush_text();
1840        if let Some(div) = self.div_stack.pop() {
1841            self.div_stack.push(f(div));
1842        }
1843    }
1844
1845    fn pop_div(&mut self) {
1846        self.flush_text();
1847        let div = self.div_stack.pop().unwrap().into_any_element();
1848        self.div_stack.last_mut().unwrap().extend(iter::once(div));
1849    }
1850
1851    fn push_list(&mut self, bullet_index: Option<u64>) {
1852        self.list_stack.push(ListStackEntry { bullet_index });
1853    }
1854
1855    fn next_bullet_index(&mut self) -> Option<u64> {
1856        self.list_stack.last_mut().and_then(|entry| {
1857            let item_index = entry.bullet_index.as_mut()?;
1858            *item_index += 1;
1859            Some(*item_index - 1)
1860        })
1861    }
1862
1863    fn pop_list(&mut self) {
1864        self.list_stack.pop();
1865    }
1866
1867    fn push_code_block(&mut self, language: Option<Arc<Language>>) {
1868        self.code_block_stack.push(language);
1869    }
1870
1871    fn pop_code_block(&mut self) {
1872        self.code_block_stack.pop();
1873    }
1874
1875    fn push_link(&mut self, destination_url: SharedString, source_range: Range<usize>) {
1876        self.rendered_links.push(RenderedLink {
1877            source_range,
1878            destination_url,
1879        });
1880    }
1881
1882    fn push_text(&mut self, text: &str, source_range: Range<usize>) {
1883        self.pending_line.source_mappings.push(SourceMapping {
1884            rendered_index: self.pending_line.text.len(),
1885            source_index: source_range.start,
1886        });
1887        self.pending_line.text.push_str(text);
1888        self.current_source_index = source_range.end;
1889
1890        if let Some(Some(language)) = self.code_block_stack.last() {
1891            let mut offset = 0;
1892            for (range, highlight_id) in language.highlight_text(&Rope::from(text), 0..text.len()) {
1893                if range.start > offset {
1894                    self.pending_line
1895                        .runs
1896                        .push(self.text_style().to_run(range.start - offset));
1897                }
1898
1899                let mut run_style = self.text_style();
1900                if let Some(highlight) = highlight_id.style(&self.syntax_theme) {
1901                    run_style = run_style.highlight(highlight);
1902                }
1903                self.pending_line.runs.push(run_style.to_run(range.len()));
1904                offset = range.end;
1905            }
1906
1907            if offset < text.len() {
1908                self.pending_line
1909                    .runs
1910                    .push(self.text_style().to_run(text.len() - offset));
1911            }
1912        } else {
1913            self.pending_line
1914                .runs
1915                .push(self.text_style().to_run(text.len()));
1916        }
1917    }
1918
1919    fn trim_trailing_newline(&mut self) {
1920        if self.pending_line.text.ends_with('\n') {
1921            self.pending_line
1922                .text
1923                .truncate(self.pending_line.text.len() - 1);
1924            self.pending_line.runs.last_mut().unwrap().len -= 1;
1925            self.current_source_index -= 1;
1926        }
1927    }
1928
1929    fn flush_text(&mut self) {
1930        let line = mem::take(&mut self.pending_line);
1931        if line.text.is_empty() {
1932            return;
1933        }
1934
1935        let text = StyledText::new(line.text).with_runs(line.runs);
1936        self.rendered_lines.push(RenderedLine {
1937            layout: text.layout().clone(),
1938            source_mappings: line.source_mappings,
1939            source_end: self.current_source_index,
1940            language: self.code_block_stack.last().cloned().flatten(),
1941        });
1942        self.div_stack.last_mut().unwrap().extend([text.into_any()]);
1943    }
1944
1945    fn build(mut self) -> RenderedMarkdown {
1946        debug_assert_eq!(self.div_stack.len(), 1);
1947        self.flush_text();
1948        RenderedMarkdown {
1949            element: self.div_stack.pop().unwrap().into_any_element(),
1950            text: RenderedText {
1951                lines: self.rendered_lines.into(),
1952                links: self.rendered_links.into(),
1953            },
1954        }
1955    }
1956}
1957
1958struct RenderedLine {
1959    layout: TextLayout,
1960    source_mappings: Vec<SourceMapping>,
1961    source_end: usize,
1962    language: Option<Arc<Language>>,
1963}
1964
1965impl RenderedLine {
1966    fn rendered_index_for_source_index(&self, source_index: usize) -> usize {
1967        if source_index >= self.source_end {
1968            return self.layout.len();
1969        }
1970
1971        let mapping = match self
1972            .source_mappings
1973            .binary_search_by_key(&source_index, |probe| probe.source_index)
1974        {
1975            Ok(ix) => &self.source_mappings[ix],
1976            Err(ix) => &self.source_mappings[ix - 1],
1977        };
1978        mapping.rendered_index + (source_index - mapping.source_index)
1979    }
1980
1981    fn source_index_for_rendered_index(&self, rendered_index: usize) -> usize {
1982        if rendered_index >= self.layout.len() {
1983            return self.source_end;
1984        }
1985
1986        let mapping = match self
1987            .source_mappings
1988            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
1989        {
1990            Ok(ix) => &self.source_mappings[ix],
1991            Err(ix) => &self.source_mappings[ix - 1],
1992        };
1993        mapping.source_index + (rendered_index - mapping.rendered_index)
1994    }
1995
1996    /// Returns the source index for use as an exclusive range end at a word/selection boundary.
1997    /// When the rendered index is exactly at the start of a segment with a gap from the previous
1998    /// segment (e.g., after stripped markdown syntax like backticks), this returns the end of the
1999    /// previous segment rather than the start of the current one.
2000    fn source_index_for_exclusive_rendered_end(&self, rendered_index: usize) -> usize {
2001        if rendered_index >= self.layout.len() {
2002            return self.source_end;
2003        }
2004
2005        let ix = match self
2006            .source_mappings
2007            .binary_search_by_key(&rendered_index, |probe| probe.rendered_index)
2008        {
2009            Ok(ix) => ix,
2010            Err(ix) => {
2011                return self.source_mappings[ix - 1].source_index
2012                    + (rendered_index - self.source_mappings[ix - 1].rendered_index);
2013            }
2014        };
2015
2016        // Exact match at the start of a segment. Check if there's a gap from the previous segment.
2017        if ix > 0 {
2018            let prev_mapping = &self.source_mappings[ix - 1];
2019            let mapping = &self.source_mappings[ix];
2020            let prev_segment_len = mapping.rendered_index - prev_mapping.rendered_index;
2021            let prev_source_end = prev_mapping.source_index + prev_segment_len;
2022            if prev_source_end < mapping.source_index {
2023                return prev_source_end;
2024            }
2025        }
2026
2027        self.source_mappings[ix].source_index
2028    }
2029
2030    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2031        let line_rendered_index;
2032        let out_of_bounds;
2033        match self.layout.index_for_position(position) {
2034            Ok(ix) => {
2035                line_rendered_index = ix;
2036                out_of_bounds = false;
2037            }
2038            Err(ix) => {
2039                line_rendered_index = ix;
2040                out_of_bounds = true;
2041            }
2042        };
2043        let source_index = self.source_index_for_rendered_index(line_rendered_index);
2044        if out_of_bounds {
2045            Err(source_index)
2046        } else {
2047            Ok(source_index)
2048        }
2049    }
2050}
2051
2052#[derive(Copy, Clone, Debug, Default)]
2053struct SourceMapping {
2054    rendered_index: usize,
2055    source_index: usize,
2056}
2057
2058pub struct RenderedMarkdown {
2059    element: AnyElement,
2060    text: RenderedText,
2061}
2062
2063#[derive(Clone)]
2064struct RenderedText {
2065    lines: Rc<[RenderedLine]>,
2066    links: Rc<[RenderedLink]>,
2067}
2068
2069#[derive(Debug, Clone, Eq, PartialEq)]
2070struct RenderedLink {
2071    source_range: Range<usize>,
2072    destination_url: SharedString,
2073}
2074
2075impl RenderedText {
2076    fn source_index_for_position(&self, position: Point<Pixels>) -> Result<usize, usize> {
2077        let mut lines = self.lines.iter().peekable();
2078        let mut fallback_line: Option<&RenderedLine> = None;
2079
2080        while let Some(line) = lines.next() {
2081            let line_bounds = line.layout.bounds();
2082
2083            // Exact match: position is within bounds (handles overlapping bounds like table columns)
2084            if line_bounds.contains(&position) {
2085                return line.source_index_for_position(position);
2086            }
2087
2088            // Track fallback for Y-coordinate based matching
2089            if position.y <= line_bounds.bottom() && fallback_line.is_none() {
2090                fallback_line = Some(line);
2091            }
2092
2093            // Handle gap between lines
2094            if position.y > line_bounds.bottom() {
2095                if let Some(next_line) = lines.peek()
2096                    && position.y < next_line.layout.bounds().top()
2097                {
2098                    return Err(line.source_end);
2099                }
2100            }
2101        }
2102
2103        // Fall back to Y-coordinate matched line
2104        if let Some(line) = fallback_line {
2105            return line.source_index_for_position(position);
2106        }
2107
2108        Err(self.lines.last().map_or(0, |line| line.source_end))
2109    }
2110
2111    fn position_for_source_index(&self, source_index: usize) -> Option<(Point<Pixels>, Pixels)> {
2112        for line in self.lines.iter() {
2113            let line_source_start = line.source_mappings.first().unwrap().source_index;
2114            if source_index < line_source_start {
2115                break;
2116            } else if source_index > line.source_end {
2117                continue;
2118            } else {
2119                let line_height = line.layout.line_height();
2120                let rendered_index_within_line = line.rendered_index_for_source_index(source_index);
2121                let position = line.layout.position_for_index(rendered_index_within_line)?;
2122                return Some((position, line_height));
2123            }
2124        }
2125        None
2126    }
2127
2128    fn surrounding_word_range(&self, source_index: usize) -> Range<usize> {
2129        for line in self.lines.iter() {
2130            if source_index > line.source_end {
2131                continue;
2132            }
2133
2134            let line_rendered_start = line.source_mappings.first().unwrap().rendered_index;
2135            let rendered_index_in_line =
2136                line.rendered_index_for_source_index(source_index) - line_rendered_start;
2137            let text = line.layout.text();
2138
2139            let scope = line.language.as_ref().map(|l| l.default_scope());
2140            let classifier = CharClassifier::new(scope);
2141
2142            let mut prev_chars = text[..rendered_index_in_line].chars().rev().peekable();
2143            let mut next_chars = text[rendered_index_in_line..].chars().peekable();
2144
2145            let word_kind = std::cmp::max(
2146                prev_chars.peek().map(|&c| classifier.kind(c)),
2147                next_chars.peek().map(|&c| classifier.kind(c)),
2148            );
2149
2150            let mut start = rendered_index_in_line;
2151            for c in prev_chars {
2152                if Some(classifier.kind(c)) == word_kind {
2153                    start -= c.len_utf8();
2154                } else {
2155                    break;
2156                }
2157            }
2158
2159            let mut end = rendered_index_in_line;
2160            for c in next_chars {
2161                if Some(classifier.kind(c)) == word_kind {
2162                    end += c.len_utf8();
2163                } else {
2164                    break;
2165                }
2166            }
2167
2168            return line.source_index_for_rendered_index(line_rendered_start + start)
2169                ..line.source_index_for_exclusive_rendered_end(line_rendered_start + end);
2170        }
2171
2172        source_index..source_index
2173    }
2174
2175    fn surrounding_line_range(&self, source_index: usize) -> Range<usize> {
2176        for line in self.lines.iter() {
2177            if source_index > line.source_end {
2178                continue;
2179            }
2180            let line_source_start = line.source_mappings.first().unwrap().source_index;
2181            return line_source_start..line.source_end;
2182        }
2183
2184        source_index..source_index
2185    }
2186
2187    fn text_for_range(&self, range: Range<usize>) -> String {
2188        let mut accumulator = String::new();
2189
2190        for line in self.lines.iter() {
2191            if range.start > line.source_end {
2192                continue;
2193            }
2194            let line_source_start = line.source_mappings.first().unwrap().source_index;
2195            if range.end < line_source_start {
2196                break;
2197            }
2198
2199            let text = line.layout.text();
2200
2201            let start = if range.start < line_source_start {
2202                0
2203            } else {
2204                line.rendered_index_for_source_index(range.start)
2205            };
2206            let end = if range.end > line.source_end {
2207                line.rendered_index_for_source_index(line.source_end)
2208            } else {
2209                line.rendered_index_for_source_index(range.end)
2210            }
2211            .min(text.len());
2212
2213            accumulator.push_str(&text[start..end]);
2214            accumulator.push('\n');
2215        }
2216        // Remove trailing newline
2217        accumulator.pop();
2218        accumulator
2219    }
2220
2221    fn link_for_position(&self, position: Point<Pixels>) -> Option<&RenderedLink> {
2222        let source_index = self.source_index_for_position(position).ok()?;
2223        self.links
2224            .iter()
2225            .find(|link| link.source_range.contains(&source_index))
2226    }
2227}
2228
2229#[cfg(test)]
2230mod tests {
2231    use super::*;
2232    use gpui::{TestAppContext, size};
2233    use language::{Language, LanguageConfig, LanguageMatcher};
2234    use std::sync::Arc;
2235
2236    fn ensure_theme_initialized(cx: &mut TestAppContext) {
2237        cx.update(|cx| {
2238            if !cx.has_global::<settings::SettingsStore>() {
2239                settings::init(cx);
2240            }
2241            if !cx.has_global::<theme::GlobalTheme>() {
2242                theme::init(theme::LoadThemes::JustBase, cx);
2243            }
2244        });
2245    }
2246
2247    #[gpui::test]
2248    fn test_mappings(cx: &mut TestAppContext) {
2249        // Formatting.
2250        assert_mappings(
2251            &render_markdown("He*l*lo", cx),
2252            vec![vec![(0, 0), (1, 1), (2, 3), (3, 5), (4, 6), (5, 7)]],
2253        );
2254
2255        // Multiple lines.
2256        assert_mappings(
2257            &render_markdown("Hello\n\nWorld", cx),
2258            vec![
2259                vec![(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5)],
2260                vec![(0, 7), (1, 8), (2, 9), (3, 10), (4, 11), (5, 12)],
2261            ],
2262        );
2263
2264        // Multi-byte characters.
2265        assert_mappings(
2266            &render_markdown("αβγ\n\nδεζ", cx),
2267            vec![
2268                vec![(0, 0), (2, 2), (4, 4), (6, 6)],
2269                vec![(0, 8), (2, 10), (4, 12), (6, 14)],
2270            ],
2271        );
2272
2273        // Smart quotes.
2274        assert_mappings(&render_markdown("\"", cx), vec![vec![(0, 0), (3, 1)]]);
2275        assert_mappings(
2276            &render_markdown("\"hey\"", cx),
2277            vec![vec![(0, 0), (3, 1), (4, 2), (5, 3), (6, 4), (9, 5)]],
2278        );
2279
2280        // HTML Comments are ignored
2281        assert_mappings(
2282            &render_markdown(
2283                "<!--\nrdoc-file=string.c\n- str.intern   -> symbol\n- str.to_sym   -> symbol\n-->\nReturns",
2284                cx,
2285            ),
2286            vec![vec![
2287                (0, 78),
2288                (1, 79),
2289                (2, 80),
2290                (3, 81),
2291                (4, 82),
2292                (5, 83),
2293                (6, 84),
2294            ]],
2295        );
2296    }
2297
2298    fn render_markdown(markdown: &str, cx: &mut TestAppContext) -> RenderedText {
2299        render_markdown_with_language_registry(markdown, None, cx)
2300    }
2301
2302    fn render_markdown_with_language_registry(
2303        markdown: &str,
2304        language_registry: Option<Arc<LanguageRegistry>>,
2305        cx: &mut TestAppContext,
2306    ) -> RenderedText {
2307        struct TestWindow;
2308
2309        impl Render for TestWindow {
2310            fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
2311                div()
2312            }
2313        }
2314
2315        ensure_theme_initialized(cx);
2316
2317        let (_, cx) = cx.add_window_view(|_, _| TestWindow);
2318        let markdown =
2319            cx.new(|cx| Markdown::new(markdown.to_string().into(), language_registry, None, cx));
2320        cx.run_until_parked();
2321        let (rendered, _) = cx.draw(
2322            Default::default(),
2323            size(px(600.0), px(600.0)),
2324            |_window, _cx| {
2325                MarkdownElement::new(markdown, MarkdownStyle::default()).code_block_renderer(
2326                    CodeBlockRenderer::Default {
2327                        copy_button: false,
2328                        copy_button_on_hover: false,
2329                        border: false,
2330                    },
2331                )
2332            },
2333        );
2334        rendered.text
2335    }
2336
2337    #[gpui::test]
2338    fn test_surrounding_word_range(cx: &mut TestAppContext) {
2339        let rendered = render_markdown("Hello world tesεζ", cx);
2340
2341        // Test word selection for "Hello"
2342        let word_range = rendered.surrounding_word_range(2); // Simulate click on 'l' in "Hello"
2343        let selected_text = rendered.text_for_range(word_range);
2344        assert_eq!(selected_text, "Hello");
2345
2346        // Test word selection for "world"
2347        let word_range = rendered.surrounding_word_range(7); // Simulate click on 'o' in "world"
2348        let selected_text = rendered.text_for_range(word_range);
2349        assert_eq!(selected_text, "world");
2350
2351        // Test word selection for "tesεζ"
2352        let word_range = rendered.surrounding_word_range(14); // Simulate click on 's' in "tesεζ"
2353        let selected_text = rendered.text_for_range(word_range);
2354        assert_eq!(selected_text, "tesεζ");
2355
2356        // Test word selection at word boundary (space)
2357        let word_range = rendered.surrounding_word_range(5); // Simulate click on space between "Hello" and "world", expect highlighting word to the left
2358        let selected_text = rendered.text_for_range(word_range);
2359        assert_eq!(selected_text, "Hello");
2360    }
2361
2362    #[gpui::test]
2363    fn test_surrounding_line_range(cx: &mut TestAppContext) {
2364        let rendered = render_markdown("First line\n\nSecond line\n\nThird lineεζ", cx);
2365
2366        // Test getting line range for first line
2367        let line_range = rendered.surrounding_line_range(5); // Simulate click somewhere in first line
2368        let selected_text = rendered.text_for_range(line_range);
2369        assert_eq!(selected_text, "First line");
2370
2371        // Test getting line range for second line
2372        let line_range = rendered.surrounding_line_range(13); // Simulate click at beginning in second line
2373        let selected_text = rendered.text_for_range(line_range);
2374        assert_eq!(selected_text, "Second line");
2375
2376        // Test getting line range for third line
2377        let line_range = rendered.surrounding_line_range(37); // Simulate click at end of third line with multi-byte chars
2378        let selected_text = rendered.text_for_range(line_range);
2379        assert_eq!(selected_text, "Third lineεζ");
2380    }
2381
2382    #[gpui::test]
2383    fn test_selection_head_movement(cx: &mut TestAppContext) {
2384        let rendered = render_markdown("Hello world test", cx);
2385
2386        let mut selection = Selection {
2387            start: 5,
2388            end: 5,
2389            reversed: false,
2390            pending: false,
2391            mode: SelectMode::Character,
2392        };
2393
2394        // Test forward selection
2395        selection.set_head(10, &rendered);
2396        assert_eq!(selection.start, 5);
2397        assert_eq!(selection.end, 10);
2398        assert!(!selection.reversed);
2399        assert_eq!(selection.tail(), 5);
2400
2401        // Test backward selection
2402        selection.set_head(2, &rendered);
2403        assert_eq!(selection.start, 2);
2404        assert_eq!(selection.end, 5);
2405        assert!(selection.reversed);
2406        assert_eq!(selection.tail(), 5);
2407
2408        // Test forward selection again from reversed state
2409        selection.set_head(15, &rendered);
2410        assert_eq!(selection.start, 5);
2411        assert_eq!(selection.end, 15);
2412        assert!(!selection.reversed);
2413        assert_eq!(selection.tail(), 5);
2414    }
2415
2416    #[gpui::test]
2417    fn test_word_selection_drag(cx: &mut TestAppContext) {
2418        let rendered = render_markdown("Hello world test", cx);
2419
2420        // Start with a simulated double-click on "world" (index 6-10)
2421        let word_range = rendered.surrounding_word_range(7); // Click on 'o' in "world"
2422        let mut selection = Selection {
2423            start: word_range.start,
2424            end: word_range.end,
2425            reversed: false,
2426            pending: true,
2427            mode: SelectMode::Word(word_range),
2428        };
2429
2430        // Drag forward to "test" - should expand selection to include "test"
2431        selection.set_head(13, &rendered); // Index in "test"
2432        assert_eq!(selection.start, 6); // Start of "world"
2433        assert_eq!(selection.end, 16); // End of "test"
2434        assert!(!selection.reversed);
2435        let selected_text = rendered.text_for_range(selection.start..selection.end);
2436        assert_eq!(selected_text, "world test");
2437
2438        // Drag backward to "Hello" - should expand selection to include "Hello"
2439        selection.set_head(2, &rendered); // Index in "Hello"
2440        assert_eq!(selection.start, 0); // Start of "Hello"
2441        assert_eq!(selection.end, 11); // End of "world" (original selection)
2442        assert!(selection.reversed);
2443        let selected_text = rendered.text_for_range(selection.start..selection.end);
2444        assert_eq!(selected_text, "Hello world");
2445
2446        // Drag back within original word - should revert to original selection
2447        selection.set_head(8, &rendered); // Back within "world"
2448        assert_eq!(selection.start, 6); // Start of "world"
2449        assert_eq!(selection.end, 11); // End of "world"
2450        assert!(!selection.reversed);
2451        let selected_text = rendered.text_for_range(selection.start..selection.end);
2452        assert_eq!(selected_text, "world");
2453    }
2454
2455    #[gpui::test]
2456    fn test_selection_with_markdown_formatting(cx: &mut TestAppContext) {
2457        let rendered = render_markdown(
2458            "This is **bold** text, this is *italic* text, use `code` here",
2459            cx,
2460        );
2461        let word_range = rendered.surrounding_word_range(10); // Inside "bold"
2462        let selected_text = rendered.text_for_range(word_range);
2463        assert_eq!(selected_text, "bold");
2464
2465        let word_range = rendered.surrounding_word_range(32); // Inside "italic"
2466        let selected_text = rendered.text_for_range(word_range);
2467        assert_eq!(selected_text, "italic");
2468
2469        let word_range = rendered.surrounding_word_range(51); // Inside "code"
2470        let selected_text = rendered.text_for_range(word_range);
2471        assert_eq!(selected_text, "code");
2472    }
2473
2474    #[gpui::test]
2475    fn test_table_column_selection(cx: &mut TestAppContext) {
2476        let rendered = render_markdown("| a | b |\n|---|---|\n| c | d |", cx);
2477
2478        assert!(rendered.lines.len() >= 2);
2479        let first_bounds = rendered.lines[0].layout.bounds();
2480        let second_bounds = rendered.lines[1].layout.bounds();
2481
2482        let first_index = match rendered.source_index_for_position(first_bounds.center()) {
2483            Ok(index) | Err(index) => index,
2484        };
2485        let second_index = match rendered.source_index_for_position(second_bounds.center()) {
2486            Ok(index) | Err(index) => index,
2487        };
2488
2489        let first_word = rendered.text_for_range(rendered.surrounding_word_range(first_index));
2490        let second_word = rendered.text_for_range(rendered.surrounding_word_range(second_index));
2491
2492        assert_eq!(first_word, "a");
2493        assert_eq!(second_word, "b");
2494    }
2495
2496    #[gpui::test]
2497    fn test_inline_code_word_selection_excludes_backticks(cx: &mut TestAppContext) {
2498        // Test that double-clicking on inline code selects just the code content,
2499        // not the backticks. This verifies the fix for the bug where selecting
2500        // inline code would include the trailing backtick.
2501        let rendered = render_markdown("use `blah` here", cx);
2502
2503        // Source layout: "use `blah` here"
2504        //                 0123456789...
2505        // The inline code "blah" is at source positions 5-8 (content range 5..9)
2506
2507        // Click inside "blah" - should select just "blah", not "blah`"
2508        let word_range = rendered.surrounding_word_range(6); // 'l' in "blah"
2509
2510        // text_for_range extracts from the rendered text (without backticks), so it
2511        // would return "blah" even with a wrong source range. We check it anyway.
2512        let selected_text = rendered.text_for_range(word_range.clone());
2513        assert_eq!(selected_text, "blah");
2514
2515        // The source range is what matters for copy_as_markdown and selected_text,
2516        // which extract directly from the source. With the bug, this would be 5..10
2517        // which includes the closing backtick at position 9.
2518        assert_eq!(word_range, 5..9);
2519    }
2520
2521    #[gpui::test]
2522    fn test_surrounding_word_range_respects_word_characters(cx: &mut TestAppContext) {
2523        let rendered = render_markdown("foo.bar() baz", cx);
2524
2525        // Double clicking on 'f' in "foo" - should select just "foo"
2526        let word_range = rendered.surrounding_word_range(0);
2527        let selected_text = rendered.text_for_range(word_range);
2528        assert_eq!(selected_text, "foo");
2529
2530        // Double clicking on 'b' in "bar" - should select just "bar"
2531        let word_range = rendered.surrounding_word_range(4);
2532        let selected_text = rendered.text_for_range(word_range);
2533        assert_eq!(selected_text, "bar");
2534
2535        // Double clicking on 'b' in "baz" - should select "baz"
2536        let word_range = rendered.surrounding_word_range(10);
2537        let selected_text = rendered.text_for_range(word_range);
2538        assert_eq!(selected_text, "baz");
2539
2540        // Double clicking selects word characters in code blocks
2541        let javascript_language = Arc::new(Language::new(
2542            LanguageConfig {
2543                name: "JavaScript".into(),
2544                matcher: LanguageMatcher {
2545                    path_suffixes: vec!["js".to_string()],
2546                    ..Default::default()
2547                },
2548                word_characters: ['$', '#'].into_iter().collect(),
2549                ..Default::default()
2550            },
2551            None,
2552        ));
2553
2554        let language_registry = Arc::new(LanguageRegistry::test(cx.executor()));
2555        language_registry.add(javascript_language);
2556
2557        let rendered = render_markdown_with_language_registry(
2558            "```javascript\n$foo #bar\n```",
2559            Some(language_registry),
2560            cx,
2561        );
2562
2563        let word_range = rendered.surrounding_word_range(14);
2564        let selected_text = rendered.text_for_range(word_range);
2565        assert_eq!(selected_text, "$foo");
2566
2567        let word_range = rendered.surrounding_word_range(19);
2568        let selected_text = rendered.text_for_range(word_range);
2569        assert_eq!(selected_text, "#bar");
2570    }
2571
2572    #[gpui::test]
2573    fn test_all_selection(cx: &mut TestAppContext) {
2574        let rendered = render_markdown("Hello world\n\nThis is a test\n\nwith multiple lines", cx);
2575
2576        let total_length = rendered
2577            .lines
2578            .last()
2579            .map(|line| line.source_end)
2580            .unwrap_or(0);
2581
2582        let mut selection = Selection {
2583            start: 0,
2584            end: total_length,
2585            reversed: false,
2586            pending: true,
2587            mode: SelectMode::All,
2588        };
2589
2590        selection.set_head(5, &rendered); // Try to set head in middle
2591        assert_eq!(selection.start, 0);
2592        assert_eq!(selection.end, total_length);
2593        assert!(!selection.reversed);
2594
2595        selection.set_head(25, &rendered); // Try to set head near end
2596        assert_eq!(selection.start, 0);
2597        assert_eq!(selection.end, total_length);
2598        assert!(!selection.reversed);
2599
2600        let selected_text = rendered.text_for_range(selection.start..selection.end);
2601        assert_eq!(
2602            selected_text,
2603            "Hello world\nThis is a test\nwith multiple lines"
2604        );
2605    }
2606
2607    #[test]
2608    fn test_escape() {
2609        assert_eq!(Markdown::escape("hello `world`"), "hello \\`world\\`");
2610        assert_eq!(
2611            Markdown::escape("hello\n    cool world"),
2612            "hello\n\ncool world"
2613        );
2614    }
2615
2616    #[track_caller]
2617    fn assert_mappings(rendered: &RenderedText, expected: Vec<Vec<(usize, usize)>>) {
2618        assert_eq!(rendered.lines.len(), expected.len(), "line count mismatch");
2619        for (line_ix, line_mappings) in expected.into_iter().enumerate() {
2620            let line = &rendered.lines[line_ix];
2621
2622            assert!(
2623                line.source_mappings.windows(2).all(|mappings| {
2624                    mappings[0].source_index < mappings[1].source_index
2625                        && mappings[0].rendered_index < mappings[1].rendered_index
2626                }),
2627                "line {} has duplicate mappings: {:?}",
2628                line_ix,
2629                line.source_mappings
2630            );
2631
2632            for (rendered_ix, source_ix) in line_mappings {
2633                assert_eq!(
2634                    line.source_index_for_rendered_index(rendered_ix),
2635                    source_ix,
2636                    "line {}, rendered_ix {}",
2637                    line_ix,
2638                    rendered_ix
2639                );
2640
2641                assert_eq!(
2642                    line.rendered_index_for_source_index(source_ix),
2643                    rendered_ix,
2644                    "line {}, source_ix {}",
2645                    line_ix,
2646                    source_ix
2647                );
2648            }
2649        }
2650    }
2651}