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