1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSnapshot, SelectPhase, SoftWrap, ToPoint,
   4    MAX_LINE_LEN,
   5};
   6use crate::{
   7    display_map::{BlockStyle, DisplaySnapshot, FoldStatus, TransformBlock},
   8    git::{diff_hunk_to_display, DisplayDiffHunk},
   9    hover_popover::{
  10        hide_hover, hover_at, HOVER_POPOVER_GAP, MIN_POPOVER_CHARACTER_WIDTH,
  11        MIN_POPOVER_LINE_HEIGHT,
  12    },
  13    link_go_to_definition::{
  14        go_to_fetched_definition, go_to_fetched_type_definition, update_go_to_definition_link,
  15    },
  16    mouse_context_menu, EditorStyle, GutterHover, UnfoldAt,
  17};
  18use clock::ReplicaId;
  19use collections::{BTreeMap, HashMap};
  20use git::diff::DiffHunkStatus;
  21use gpui::{
  22    color::Color,
  23    elements::*,
  24    fonts::{HighlightStyle, TextStyle, Underline},
  25    geometry::{
  26        rect::RectF,
  27        vector::{vec2f, Vector2F},
  28        PathBuilder,
  29    },
  30    json::{self, ToJson},
  31    platform::{CursorStyle, Modifiers, MouseButton, MouseButtonEvent, MouseMovedEvent},
  32    text_layout::{self, Line, RunStyle, TextLayoutCache},
  33    AnyElement, Axis, Border, CursorRegion, Element, EventContext, FontCache, LayoutContext,
  34    MouseRegion, Quad, SceneBuilder, SizeConstraint, ViewContext, WindowContext,
  35};
  36use itertools::Itertools;
  37use json::json;
  38use language::{Bias, CursorShape, DiagnosticSeverity, OffsetUtf16, Selection};
  39use project::ProjectPath;
  40use settings::{GitGutter, Settings, ShowWhitespaces};
  41use smallvec::SmallVec;
  42use std::{
  43    borrow::Cow,
  44    cmp::{self, Ordering},
  45    fmt::Write,
  46    iter,
  47    ops::Range,
  48    sync::Arc,
  49};
  50use workspace::item::Item;
  51
  52enum FoldMarkers {}
  53
  54struct SelectionLayout {
  55    head: DisplayPoint,
  56    cursor_shape: CursorShape,
  57    range: Range<DisplayPoint>,
  58}
  59
  60impl SelectionLayout {
  61    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  62        selection: Selection<T>,
  63        line_mode: bool,
  64        cursor_shape: CursorShape,
  65        map: &DisplaySnapshot,
  66    ) -> Self {
  67        if line_mode {
  68            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  69            let point_range = map.expand_to_line(selection.range());
  70            Self {
  71                head: selection.head().to_display_point(map),
  72                cursor_shape,
  73                range: point_range.start.to_display_point(map)
  74                    ..point_range.end.to_display_point(map),
  75            }
  76        } else {
  77            let selection = selection.map(|p| p.to_display_point(map));
  78            Self {
  79                head: selection.head(),
  80                cursor_shape,
  81                range: selection.range(),
  82            }
  83        }
  84    }
  85}
  86
  87#[derive(Clone)]
  88pub struct EditorElement {
  89    style: Arc<EditorStyle>,
  90}
  91
  92impl EditorElement {
  93    pub fn new(style: EditorStyle) -> Self {
  94        Self {
  95            style: Arc::new(style),
  96        }
  97    }
  98
  99    fn attach_mouse_handlers(
 100        scene: &mut SceneBuilder,
 101        position_map: &Arc<PositionMap>,
 102        has_popovers: bool,
 103        visible_bounds: RectF,
 104        text_bounds: RectF,
 105        gutter_bounds: RectF,
 106        bounds: RectF,
 107        cx: &mut ViewContext<Editor>,
 108    ) {
 109        enum EditorElementMouseHandlers {}
 110        scene.push_mouse_region(
 111            MouseRegion::new::<EditorElementMouseHandlers>(
 112                cx.view_id(),
 113                cx.view_id(),
 114                visible_bounds,
 115            )
 116            .on_down(MouseButton::Left, {
 117                let position_map = position_map.clone();
 118                move |event, editor, cx| {
 119                    if !Self::mouse_down(
 120                        editor,
 121                        event.platform_event,
 122                        position_map.as_ref(),
 123                        text_bounds,
 124                        gutter_bounds,
 125                        cx,
 126                    ) {
 127                        cx.propagate_event();
 128                    }
 129                }
 130            })
 131            .on_down(MouseButton::Right, {
 132                let position_map = position_map.clone();
 133                move |event, editor, cx| {
 134                    if !Self::mouse_right_down(
 135                        editor,
 136                        event.position,
 137                        position_map.as_ref(),
 138                        text_bounds,
 139                        cx,
 140                    ) {
 141                        cx.propagate_event();
 142                    }
 143                }
 144            })
 145            .on_up(MouseButton::Left, {
 146                let position_map = position_map.clone();
 147                move |event, editor, cx| {
 148                    if !Self::mouse_up(
 149                        editor,
 150                        event.position,
 151                        event.cmd,
 152                        event.shift,
 153                        position_map.as_ref(),
 154                        text_bounds,
 155                        cx,
 156                    ) {
 157                        cx.propagate_event()
 158                    }
 159                }
 160            })
 161            .on_drag(MouseButton::Left, {
 162                let position_map = position_map.clone();
 163                move |event, editor, cx| {
 164                    if !Self::mouse_dragged(
 165                        editor,
 166                        event.platform_event,
 167                        position_map.as_ref(),
 168                        text_bounds,
 169                        cx,
 170                    ) {
 171                        cx.propagate_event()
 172                    }
 173                }
 174            })
 175            .on_move({
 176                let position_map = position_map.clone();
 177                move |event, editor, cx| {
 178                    if !Self::mouse_moved(
 179                        editor,
 180                        event.platform_event,
 181                        &position_map,
 182                        text_bounds,
 183                        cx,
 184                    ) {
 185                        cx.propagate_event()
 186                    }
 187                }
 188            })
 189            .on_move_out(move |_, editor: &mut Editor, cx| {
 190                if has_popovers {
 191                    hide_hover(editor, cx);
 192                }
 193            })
 194            .on_scroll({
 195                let position_map = position_map.clone();
 196                move |event, editor, cx| {
 197                    if !Self::scroll(
 198                        editor,
 199                        event.position,
 200                        *event.delta.raw(),
 201                        event.delta.precise(),
 202                        &position_map,
 203                        bounds,
 204                        cx,
 205                    ) {
 206                        cx.propagate_event()
 207                    }
 208                }
 209            }),
 210        );
 211
 212        enum GutterHandlers {}
 213        scene.push_mouse_region(
 214            MouseRegion::new::<GutterHandlers>(cx.view_id(), cx.view_id() + 1, gutter_bounds)
 215                .on_hover(|hover, editor: &mut Editor, cx| {
 216                    editor.gutter_hover(
 217                        &GutterHover {
 218                            hovered: hover.started,
 219                        },
 220                        cx,
 221                    );
 222                }),
 223        )
 224    }
 225
 226    fn mouse_down(
 227        editor: &mut Editor,
 228        MouseButtonEvent {
 229            position,
 230            modifiers:
 231                Modifiers {
 232                    shift,
 233                    ctrl,
 234                    alt,
 235                    cmd,
 236                    ..
 237                },
 238            mut click_count,
 239            ..
 240        }: MouseButtonEvent,
 241        position_map: &PositionMap,
 242        text_bounds: RectF,
 243        gutter_bounds: RectF,
 244        cx: &mut EventContext<Editor>,
 245    ) -> bool {
 246        if gutter_bounds.contains_point(position) {
 247            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 248        } else if !text_bounds.contains_point(position) {
 249            return false;
 250        }
 251
 252        let (position, target_position) = position_map.point_for_position(text_bounds, position);
 253
 254        if shift && alt {
 255            editor.select(
 256                SelectPhase::BeginColumnar {
 257                    position,
 258                    goal_column: target_position.column(),
 259                },
 260                cx,
 261            );
 262        } else if shift && !ctrl && !alt && !cmd {
 263            editor.select(
 264                SelectPhase::Extend {
 265                    position,
 266                    click_count,
 267                },
 268                cx,
 269            );
 270        } else {
 271            editor.select(
 272                SelectPhase::Begin {
 273                    position,
 274                    add: alt,
 275                    click_count,
 276                },
 277                cx,
 278            );
 279        }
 280
 281        true
 282    }
 283
 284    fn mouse_right_down(
 285        editor: &mut Editor,
 286        position: Vector2F,
 287        position_map: &PositionMap,
 288        text_bounds: RectF,
 289        cx: &mut EventContext<Editor>,
 290    ) -> bool {
 291        if !text_bounds.contains_point(position) {
 292            return false;
 293        }
 294
 295        let (point, _) = position_map.point_for_position(text_bounds, position);
 296        mouse_context_menu::deploy_context_menu(editor, position, point, cx);
 297        true
 298    }
 299
 300    fn mouse_up(
 301        editor: &mut Editor,
 302        position: Vector2F,
 303        cmd: bool,
 304        shift: bool,
 305        position_map: &PositionMap,
 306        text_bounds: RectF,
 307        cx: &mut EventContext<Editor>,
 308    ) -> bool {
 309        let end_selection = editor.has_pending_selection();
 310        let pending_nonempty_selections = editor.has_pending_nonempty_selection();
 311
 312        if end_selection {
 313            editor.select(SelectPhase::End, cx);
 314        }
 315
 316        if !pending_nonempty_selections && cmd && text_bounds.contains_point(position) {
 317            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 318
 319            if point == target_point {
 320                if shift {
 321                    go_to_fetched_type_definition(editor, point, cx);
 322                } else {
 323                    go_to_fetched_definition(editor, point, cx);
 324                }
 325
 326                return true;
 327            }
 328        }
 329
 330        end_selection
 331    }
 332
 333    fn mouse_dragged(
 334        editor: &mut Editor,
 335        MouseMovedEvent {
 336            modifiers: Modifiers { cmd, shift, .. },
 337            position,
 338            ..
 339        }: MouseMovedEvent,
 340        position_map: &PositionMap,
 341        text_bounds: RectF,
 342        cx: &mut EventContext<Editor>,
 343    ) -> bool {
 344        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 345        // Don't trigger hover popover if mouse is hovering over context menu
 346        let point = if text_bounds.contains_point(position) {
 347            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 348            if point == target_point {
 349                Some(point)
 350            } else {
 351                None
 352            }
 353        } else {
 354            None
 355        };
 356
 357        update_go_to_definition_link(editor, point, cmd, shift, cx);
 358
 359        if editor.has_pending_selection() {
 360            let mut scroll_delta = Vector2F::zero();
 361
 362            let vertical_margin = position_map.line_height.min(text_bounds.height() / 3.0);
 363            let top = text_bounds.origin_y() + vertical_margin;
 364            let bottom = text_bounds.lower_left().y() - vertical_margin;
 365            if position.y() < top {
 366                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 367            }
 368            if position.y() > bottom {
 369                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 370            }
 371
 372            let horizontal_margin = position_map.line_height.min(text_bounds.width() / 3.0);
 373            let left = text_bounds.origin_x() + horizontal_margin;
 374            let right = text_bounds.upper_right().x() - horizontal_margin;
 375            if position.x() < left {
 376                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 377                    left - position.x(),
 378                ))
 379            }
 380            if position.x() > right {
 381                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 382                    position.x() - right,
 383                ))
 384            }
 385
 386            let (position, target_position) =
 387                position_map.point_for_position(text_bounds, position);
 388
 389            editor.select(
 390                SelectPhase::Update {
 391                    position,
 392                    goal_column: target_position.column(),
 393                    scroll_position: (position_map.snapshot.scroll_position() + scroll_delta)
 394                        .clamp(Vector2F::zero(), position_map.scroll_max),
 395                },
 396                cx,
 397            );
 398            hover_at(editor, point, cx);
 399            true
 400        } else {
 401            hover_at(editor, point, cx);
 402            false
 403        }
 404    }
 405
 406    fn mouse_moved(
 407        editor: &mut Editor,
 408        MouseMovedEvent {
 409            modifiers: Modifiers { shift, cmd, .. },
 410            position,
 411            ..
 412        }: MouseMovedEvent,
 413        position_map: &PositionMap,
 414        text_bounds: RectF,
 415        cx: &mut ViewContext<Editor>,
 416    ) -> bool {
 417        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 418        // Don't trigger hover popover if mouse is hovering over context menu
 419        let point = position_to_display_point(position, text_bounds, position_map);
 420
 421        update_go_to_definition_link(editor, point, cmd, shift, cx);
 422        hover_at(editor, point, cx);
 423
 424        true
 425    }
 426
 427    fn scroll(
 428        editor: &mut Editor,
 429        position: Vector2F,
 430        mut delta: Vector2F,
 431        precise: bool,
 432        position_map: &PositionMap,
 433        bounds: RectF,
 434        cx: &mut ViewContext<Editor>,
 435    ) -> bool {
 436        if !bounds.contains_point(position) {
 437            return false;
 438        }
 439
 440        let line_height = position_map.line_height;
 441        let max_glyph_width = position_map.em_width;
 442
 443        let axis = if precise {
 444            //Trackpad
 445            position_map.snapshot.ongoing_scroll.filter(&mut delta)
 446        } else {
 447            //Not trackpad
 448            delta *= vec2f(max_glyph_width, line_height);
 449            None //Resets ongoing scroll
 450        };
 451
 452        let scroll_position = position_map.snapshot.scroll_position();
 453        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 454        let y = (scroll_position.y() * line_height - delta.y()) / line_height;
 455        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), position_map.scroll_max);
 456        editor.scroll(scroll_position, axis, cx);
 457
 458        true
 459    }
 460
 461    fn paint_background(
 462        &self,
 463        scene: &mut SceneBuilder,
 464        gutter_bounds: RectF,
 465        text_bounds: RectF,
 466        layout: &LayoutState,
 467    ) {
 468        let bounds = gutter_bounds.union_rect(text_bounds);
 469        let scroll_top =
 470            layout.position_map.snapshot.scroll_position().y() * layout.position_map.line_height;
 471        scene.push_quad(Quad {
 472            bounds: gutter_bounds,
 473            background: Some(self.style.gutter_background),
 474            border: Border::new(0., Color::transparent_black()),
 475            corner_radius: 0.,
 476        });
 477        scene.push_quad(Quad {
 478            bounds: text_bounds,
 479            background: Some(self.style.background),
 480            border: Border::new(0., Color::transparent_black()),
 481            corner_radius: 0.,
 482        });
 483
 484        if let EditorMode::Full = layout.mode {
 485            let mut active_rows = layout.active_rows.iter().peekable();
 486            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 487                let mut end_row = *start_row;
 488                while active_rows.peek().map_or(false, |r| {
 489                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 490                }) {
 491                    active_rows.next().unwrap();
 492                    end_row += 1;
 493                }
 494
 495                if !contains_non_empty_selection {
 496                    let origin = vec2f(
 497                        bounds.origin_x(),
 498                        bounds.origin_y() + (layout.position_map.line_height * *start_row as f32)
 499                            - scroll_top,
 500                    );
 501                    let size = vec2f(
 502                        bounds.width(),
 503                        layout.position_map.line_height * (end_row - start_row + 1) as f32,
 504                    );
 505                    scene.push_quad(Quad {
 506                        bounds: RectF::new(origin, size),
 507                        background: Some(self.style.active_line_background),
 508                        border: Border::default(),
 509                        corner_radius: 0.,
 510                    });
 511                }
 512            }
 513
 514            if let Some(highlighted_rows) = &layout.highlighted_rows {
 515                let origin = vec2f(
 516                    bounds.origin_x(),
 517                    bounds.origin_y()
 518                        + (layout.position_map.line_height * highlighted_rows.start as f32)
 519                        - scroll_top,
 520                );
 521                let size = vec2f(
 522                    bounds.width(),
 523                    layout.position_map.line_height * highlighted_rows.len() as f32,
 524                );
 525                scene.push_quad(Quad {
 526                    bounds: RectF::new(origin, size),
 527                    background: Some(self.style.highlighted_line_background),
 528                    border: Border::default(),
 529                    corner_radius: 0.,
 530                });
 531            }
 532        }
 533    }
 534
 535    fn paint_gutter(
 536        &mut self,
 537        scene: &mut SceneBuilder,
 538        bounds: RectF,
 539        visible_bounds: RectF,
 540        layout: &mut LayoutState,
 541        editor: &mut Editor,
 542        cx: &mut ViewContext<Editor>,
 543    ) {
 544        let line_height = layout.position_map.line_height;
 545
 546        let scroll_position = layout.position_map.snapshot.scroll_position();
 547        let scroll_top = scroll_position.y() * line_height;
 548
 549        let show_gutter = matches!(
 550            &cx.global::<Settings>()
 551                .git_overrides
 552                .git_gutter
 553                .unwrap_or_default(),
 554            GitGutter::TrackedFiles
 555        );
 556
 557        if show_gutter {
 558            Self::paint_diff_hunks(scene, bounds, layout, cx);
 559        }
 560
 561        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 562            if let Some(line) = line {
 563                let line_origin = bounds.origin()
 564                    + vec2f(
 565                        bounds.width() - line.width() - layout.gutter_padding,
 566                        ix as f32 * line_height - (scroll_top % line_height),
 567                    );
 568
 569                line.paint(scene, line_origin, visible_bounds, line_height, cx);
 570            }
 571        }
 572
 573        for (ix, fold_indicator) in layout.fold_indicators.iter_mut().enumerate() {
 574            if let Some(indicator) = fold_indicator.as_mut() {
 575                let position = vec2f(
 576                    bounds.width() - layout.gutter_padding,
 577                    ix as f32 * line_height - (scroll_top % line_height),
 578                );
 579                let centering_offset = vec2f(
 580                    (layout.gutter_padding + layout.gutter_margin - indicator.size().x()) / 2.,
 581                    (line_height - indicator.size().y()) / 2.,
 582                );
 583
 584                let indicator_origin = bounds.origin() + position + centering_offset;
 585
 586                indicator.paint(scene, indicator_origin, visible_bounds, editor, cx);
 587            }
 588        }
 589
 590        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 591            let mut x = 0.;
 592            let mut y = *row as f32 * line_height - scroll_top;
 593            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 594            y += (line_height - indicator.size().y()) / 2.;
 595            indicator.paint(
 596                scene,
 597                bounds.origin() + vec2f(x, y),
 598                visible_bounds,
 599                editor,
 600                cx,
 601            );
 602        }
 603    }
 604
 605    fn paint_diff_hunks(
 606        scene: &mut SceneBuilder,
 607        bounds: RectF,
 608        layout: &mut LayoutState,
 609        cx: &mut ViewContext<Editor>,
 610    ) {
 611        let diff_style = &cx.global::<Settings>().theme.editor.diff.clone();
 612        let line_height = layout.position_map.line_height;
 613
 614        let scroll_position = layout.position_map.snapshot.scroll_position();
 615        let scroll_top = scroll_position.y() * line_height;
 616
 617        for hunk in &layout.display_hunks {
 618            let (display_row_range, status) = match hunk {
 619                //TODO: This rendering is entirely a horrible hack
 620                &DisplayDiffHunk::Folded { display_row: row } => {
 621                    let start_y = row as f32 * line_height - scroll_top;
 622                    let end_y = start_y + line_height;
 623
 624                    let width = diff_style.removed_width_em * line_height;
 625                    let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 626                    let highlight_size = vec2f(width * 2., end_y - start_y);
 627                    let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 628
 629                    scene.push_quad(Quad {
 630                        bounds: highlight_bounds,
 631                        background: Some(diff_style.modified),
 632                        border: Border::new(0., Color::transparent_black()),
 633                        corner_radius: 1. * line_height,
 634                    });
 635
 636                    continue;
 637                }
 638
 639                DisplayDiffHunk::Unfolded {
 640                    display_row_range,
 641                    status,
 642                } => (display_row_range, status),
 643            };
 644
 645            let color = match status {
 646                DiffHunkStatus::Added => diff_style.inserted,
 647                DiffHunkStatus::Modified => diff_style.modified,
 648
 649                //TODO: This rendering is entirely a horrible hack
 650                DiffHunkStatus::Removed => {
 651                    let row = *display_row_range.start();
 652
 653                    let offset = line_height / 2.;
 654                    let start_y = row as f32 * line_height - offset - scroll_top;
 655                    let end_y = start_y + line_height;
 656
 657                    let width = diff_style.removed_width_em * line_height;
 658                    let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 659                    let highlight_size = vec2f(width * 2., end_y - start_y);
 660                    let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 661
 662                    scene.push_quad(Quad {
 663                        bounds: highlight_bounds,
 664                        background: Some(diff_style.deleted),
 665                        border: Border::new(0., Color::transparent_black()),
 666                        corner_radius: 1. * line_height,
 667                    });
 668
 669                    continue;
 670                }
 671            };
 672
 673            let start_row = *display_row_range.start();
 674            let end_row = *display_row_range.end();
 675
 676            let start_y = start_row as f32 * line_height - scroll_top;
 677            let end_y = end_row as f32 * line_height - scroll_top + line_height;
 678
 679            let width = diff_style.width_em * line_height;
 680            let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 681            let highlight_size = vec2f(width * 2., end_y - start_y);
 682            let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 683
 684            scene.push_quad(Quad {
 685                bounds: highlight_bounds,
 686                background: Some(color),
 687                border: Border::new(0., Color::transparent_black()),
 688                corner_radius: diff_style.corner_radius * line_height,
 689            });
 690        }
 691    }
 692
 693    fn paint_text(
 694        &mut self,
 695        scene: &mut SceneBuilder,
 696        bounds: RectF,
 697        visible_bounds: RectF,
 698        layout: &mut LayoutState,
 699        editor: &mut Editor,
 700        cx: &mut ViewContext<Editor>,
 701    ) {
 702        let style = &self.style;
 703        let local_replica_id = editor.replica_id(cx);
 704        let scroll_position = layout.position_map.snapshot.scroll_position();
 705        let start_row = layout.visible_display_row_range.start;
 706        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 707        let max_glyph_width = layout.position_map.em_width;
 708        let scroll_left = scroll_position.x() * max_glyph_width;
 709        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 710        let line_end_overshoot = 0.15 * layout.position_map.line_height;
 711
 712        scene.push_layer(Some(bounds));
 713
 714        scene.push_cursor_region(CursorRegion {
 715            bounds,
 716            style: if !editor.link_go_to_definition_state.definitions.is_empty() {
 717                CursorStyle::PointingHand
 718            } else {
 719                CursorStyle::IBeam
 720            },
 721        });
 722
 723        let fold_corner_radius =
 724            self.style.folds.ellipses.corner_radius_factor * layout.position_map.line_height;
 725        for (id, range, color) in layout.fold_ranges.iter() {
 726            self.paint_highlighted_range(
 727                scene,
 728                range.clone(),
 729                *color,
 730                fold_corner_radius,
 731                fold_corner_radius * 2.,
 732                layout,
 733                content_origin,
 734                scroll_top,
 735                scroll_left,
 736                bounds,
 737            );
 738
 739            for bound in range_to_bounds(
 740                &range,
 741                content_origin,
 742                scroll_left,
 743                scroll_top,
 744                &layout.visible_display_row_range,
 745                line_end_overshoot,
 746                &layout.position_map,
 747            ) {
 748                scene.push_cursor_region(CursorRegion {
 749                    bounds: bound,
 750                    style: CursorStyle::PointingHand,
 751                });
 752
 753                let display_row = range.start.row();
 754
 755                let buffer_row = DisplayPoint::new(display_row, 0)
 756                    .to_point(&layout.position_map.snapshot.display_snapshot)
 757                    .row;
 758
 759                scene.push_mouse_region(
 760                    MouseRegion::new::<FoldMarkers>(cx.view_id(), *id as usize, bound)
 761                        .on_click(MouseButton::Left, move |_, editor: &mut Editor, cx| {
 762                            editor.unfold_at(&UnfoldAt { buffer_row }, cx)
 763                        })
 764                        .with_notify_on_hover(true)
 765                        .with_notify_on_click(true),
 766                )
 767            }
 768        }
 769
 770        for (range, color) in &layout.highlighted_ranges {
 771            self.paint_highlighted_range(
 772                scene,
 773                range.clone(),
 774                *color,
 775                0.,
 776                line_end_overshoot,
 777                layout,
 778                content_origin,
 779                scroll_top,
 780                scroll_left,
 781                bounds,
 782            );
 783        }
 784
 785        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 786        let corner_radius = 0.15 * layout.position_map.line_height;
 787        let mut invisible_display_ranges = SmallVec::<[Range<DisplayPoint>; 32]>::new();
 788
 789        for (replica_id, selections) in &layout.selections {
 790            let replica_id = *replica_id;
 791            let selection_style = style.replica_selection_style(replica_id);
 792
 793            for selection in selections {
 794                if !selection.range.is_empty()
 795                    && (replica_id == local_replica_id
 796                        || Some(replica_id) == editor.leader_replica_id)
 797                {
 798                    invisible_display_ranges.push(selection.range.clone());
 799                }
 800                self.paint_highlighted_range(
 801                    scene,
 802                    selection.range.clone(),
 803                    selection_style.selection,
 804                    corner_radius,
 805                    corner_radius * 2.,
 806                    layout,
 807                    content_origin,
 808                    scroll_top,
 809                    scroll_left,
 810                    bounds,
 811                );
 812
 813                if editor.show_local_cursors(cx) || replica_id != local_replica_id {
 814                    let cursor_position = selection.head;
 815                    if layout
 816                        .visible_display_row_range
 817                        .contains(&cursor_position.row())
 818                    {
 819                        let cursor_row_layout = &layout.position_map.line_layouts
 820                            [(cursor_position.row() - start_row) as usize]
 821                            .line;
 822                        let cursor_column = cursor_position.column() as usize;
 823
 824                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 825                        let mut block_width =
 826                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 827                        if block_width == 0.0 {
 828                            block_width = layout.position_map.em_width;
 829                        }
 830                        let block_text = if let CursorShape::Block = selection.cursor_shape {
 831                            layout
 832                                .position_map
 833                                .snapshot
 834                                .chars_at(cursor_position)
 835                                .next()
 836                                .and_then(|(character, _)| {
 837                                    let font_id =
 838                                        cursor_row_layout.font_for_index(cursor_column)?;
 839                                    let text = character.to_string();
 840
 841                                    Some(cx.text_layout_cache().layout_str(
 842                                        &text,
 843                                        cursor_row_layout.font_size(),
 844                                        &[(
 845                                            text.len(),
 846                                            RunStyle {
 847                                                font_id,
 848                                                color: style.background,
 849                                                underline: Default::default(),
 850                                            },
 851                                        )],
 852                                    ))
 853                                })
 854                        } else {
 855                            None
 856                        };
 857
 858                        let x = cursor_character_x - scroll_left;
 859                        let y = cursor_position.row() as f32 * layout.position_map.line_height
 860                            - scroll_top;
 861                        cursors.push(Cursor {
 862                            color: selection_style.cursor,
 863                            block_width,
 864                            origin: vec2f(x, y),
 865                            line_height: layout.position_map.line_height,
 866                            shape: selection.cursor_shape,
 867                            block_text,
 868                        });
 869                    }
 870                }
 871            }
 872        }
 873
 874        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 875            for (ix, line_with_invisibles) in layout.position_map.line_layouts.iter().enumerate() {
 876                let row = start_row + ix as u32;
 877                line_with_invisibles.draw(
 878                    layout,
 879                    row,
 880                    scroll_top,
 881                    scene,
 882                    content_origin,
 883                    scroll_left,
 884                    visible_text_bounds,
 885                    cx,
 886                    &invisible_display_ranges,
 887                    visible_bounds,
 888                )
 889            }
 890        }
 891
 892        scene.paint_layer(Some(bounds), |scene| {
 893            for cursor in cursors {
 894                cursor.paint(scene, content_origin, cx);
 895            }
 896        });
 897
 898        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 899            scene.push_stacking_context(None, None);
 900            let cursor_row_layout =
 901                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
 902            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 903            let y = (position.row() + 1) as f32 * layout.position_map.line_height - scroll_top;
 904            let mut list_origin = content_origin + vec2f(x, y);
 905            let list_width = context_menu.size().x();
 906            let list_height = context_menu.size().y();
 907
 908            // Snap the right edge of the list to the right edge of the window if
 909            // its horizontal bounds overflow.
 910            if list_origin.x() + list_width > cx.window_size().x() {
 911                list_origin.set_x((cx.window_size().x() - list_width).max(0.));
 912            }
 913
 914            if list_origin.y() + list_height > bounds.max_y() {
 915                list_origin.set_y(list_origin.y() - layout.position_map.line_height - list_height);
 916            }
 917
 918            context_menu.paint(
 919                scene,
 920                list_origin,
 921                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 922                editor,
 923                cx,
 924            );
 925
 926            scene.pop_stacking_context();
 927        }
 928
 929        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
 930            scene.push_stacking_context(None, None);
 931
 932            // This is safe because we check on layout whether the required row is available
 933            let hovered_row_layout =
 934                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
 935
 936            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
 937            // height. This is the size we will use to decide whether to render popovers above or below
 938            // the hovered line.
 939            let first_size = hover_popovers[0].size();
 940            let height_to_reserve = first_size.y()
 941                + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.position_map.line_height;
 942
 943            // Compute Hovered Point
 944            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 945            let y = position.row() as f32 * layout.position_map.line_height - scroll_top;
 946            let hovered_point = content_origin + vec2f(x, y);
 947
 948            if hovered_point.y() - height_to_reserve > 0.0 {
 949                // There is enough space above. Render popovers above the hovered point
 950                let mut current_y = hovered_point.y();
 951                for hover_popover in hover_popovers {
 952                    let size = hover_popover.size();
 953                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
 954
 955                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 956                    if x_out_of_bounds < 0.0 {
 957                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 958                    }
 959
 960                    hover_popover.paint(
 961                        scene,
 962                        popover_origin,
 963                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 964                        editor,
 965                        cx,
 966                    );
 967
 968                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
 969                }
 970            } else {
 971                // There is not enough space above. Render popovers below the hovered point
 972                let mut current_y = hovered_point.y() + layout.position_map.line_height;
 973                for hover_popover in hover_popovers {
 974                    let size = hover_popover.size();
 975                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
 976
 977                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 978                    if x_out_of_bounds < 0.0 {
 979                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 980                    }
 981
 982                    hover_popover.paint(
 983                        scene,
 984                        popover_origin,
 985                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 986                        editor,
 987                        cx,
 988                    );
 989
 990                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
 991                }
 992            }
 993
 994            scene.pop_stacking_context();
 995        }
 996
 997        scene.pop_layer();
 998    }
 999
1000    fn paint_scrollbar(
1001        &mut self,
1002        scene: &mut SceneBuilder,
1003        bounds: RectF,
1004        layout: &mut LayoutState,
1005        cx: &mut ViewContext<Editor>,
1006    ) {
1007        enum ScrollbarMouseHandlers {}
1008        if layout.mode != EditorMode::Full {
1009            return;
1010        }
1011
1012        let style = &self.style.theme.scrollbar;
1013
1014        let top = bounds.min_y();
1015        let bottom = bounds.max_y();
1016        let right = bounds.max_x();
1017        let left = right - style.width;
1018        let row_range = &layout.scrollbar_row_range;
1019        let max_row = layout.max_row as f32 + (row_range.end - row_range.start);
1020
1021        let mut height = bounds.height();
1022        let mut first_row_y_offset = 0.0;
1023
1024        // Impose a minimum height on the scrollbar thumb
1025        let row_height = height / max_row;
1026        let min_thumb_height =
1027            style.min_height_factor * cx.font_cache.line_height(self.style.text.font_size);
1028        let thumb_height = (row_range.end - row_range.start) * row_height;
1029        if thumb_height < min_thumb_height {
1030            first_row_y_offset = (min_thumb_height - thumb_height) / 2.0;
1031            height -= min_thumb_height - thumb_height;
1032        }
1033
1034        let y_for_row = |row: f32| -> f32 { top + first_row_y_offset + row * row_height };
1035
1036        let thumb_top = y_for_row(row_range.start) - first_row_y_offset;
1037        let thumb_bottom = y_for_row(row_range.end) + first_row_y_offset;
1038        let track_bounds = RectF::from_points(vec2f(left, top), vec2f(right, bottom));
1039        let thumb_bounds = RectF::from_points(vec2f(left, thumb_top), vec2f(right, thumb_bottom));
1040
1041        if layout.show_scrollbars {
1042            scene.push_quad(Quad {
1043                bounds: track_bounds,
1044                border: style.track.border,
1045                background: style.track.background_color,
1046                ..Default::default()
1047            });
1048
1049            let diff_style = cx.global::<Settings>().theme.editor.diff.clone();
1050            for hunk in layout
1051                .position_map
1052                .snapshot
1053                .buffer_snapshot
1054                .git_diff_hunks_in_range(0..(max_row.floor() as u32), false)
1055            {
1056                let start_y = y_for_row(hunk.buffer_range.start as f32);
1057                let mut end_y = if hunk.buffer_range.start == hunk.buffer_range.end {
1058                    y_for_row((hunk.buffer_range.end + 1) as f32)
1059                } else {
1060                    y_for_row((hunk.buffer_range.end) as f32)
1061                };
1062
1063                if end_y - start_y < 1. {
1064                    end_y = start_y + 1.;
1065                }
1066                let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
1067
1068                let color = match hunk.status() {
1069                    DiffHunkStatus::Added => diff_style.inserted,
1070                    DiffHunkStatus::Modified => diff_style.modified,
1071                    DiffHunkStatus::Removed => diff_style.deleted,
1072                };
1073
1074                let border = Border {
1075                    width: 1.,
1076                    color: style.thumb.border.color,
1077                    overlay: false,
1078                    top: false,
1079                    right: true,
1080                    bottom: false,
1081                    left: true,
1082                };
1083
1084                scene.push_quad(Quad {
1085                    bounds,
1086                    background: Some(color),
1087                    border,
1088                    corner_radius: style.thumb.corner_radius,
1089                })
1090            }
1091
1092            scene.push_quad(Quad {
1093                bounds: thumb_bounds,
1094                border: style.thumb.border,
1095                background: style.thumb.background_color,
1096                corner_radius: style.thumb.corner_radius,
1097            });
1098        }
1099
1100        scene.push_cursor_region(CursorRegion {
1101            bounds: track_bounds,
1102            style: CursorStyle::Arrow,
1103        });
1104        scene.push_mouse_region(
1105            MouseRegion::new::<ScrollbarMouseHandlers>(cx.view_id(), cx.view_id(), track_bounds)
1106                .on_move(move |_, editor: &mut Editor, cx| {
1107                    editor.scroll_manager.show_scrollbar(cx);
1108                })
1109                .on_down(MouseButton::Left, {
1110                    let row_range = row_range.clone();
1111                    move |event, editor: &mut Editor, cx| {
1112                        let y = event.position.y();
1113                        if y < thumb_top || thumb_bottom < y {
1114                            let center_row = ((y - top) * max_row as f32 / height).round() as u32;
1115                            let top_row = center_row
1116                                .saturating_sub((row_range.end - row_range.start) as u32 / 2);
1117                            let mut position = editor.scroll_position(cx);
1118                            position.set_y(top_row as f32);
1119                            editor.set_scroll_position(position, cx);
1120                        } else {
1121                            editor.scroll_manager.show_scrollbar(cx);
1122                        }
1123                    }
1124                })
1125                .on_drag(MouseButton::Left, {
1126                    move |event, editor: &mut Editor, cx| {
1127                        let y = event.prev_mouse_position.y();
1128                        let new_y = event.position.y();
1129                        if thumb_top < y && y < thumb_bottom {
1130                            let mut position = editor.scroll_position(cx);
1131                            position.set_y(position.y() + (new_y - y) * (max_row as f32) / height);
1132                            if position.y() < 0.0 {
1133                                position.set_y(0.);
1134                            }
1135                            editor.set_scroll_position(position, cx);
1136                        }
1137                    }
1138                }),
1139        );
1140    }
1141
1142    #[allow(clippy::too_many_arguments)]
1143    fn paint_highlighted_range(
1144        &self,
1145        scene: &mut SceneBuilder,
1146        range: Range<DisplayPoint>,
1147        color: Color,
1148        corner_radius: f32,
1149        line_end_overshoot: f32,
1150        layout: &LayoutState,
1151        content_origin: Vector2F,
1152        scroll_top: f32,
1153        scroll_left: f32,
1154        bounds: RectF,
1155    ) {
1156        let start_row = layout.visible_display_row_range.start;
1157        let end_row = layout.visible_display_row_range.end;
1158        if range.start != range.end {
1159            let row_range = if range.end.column() == 0 {
1160                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
1161            } else {
1162                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
1163            };
1164
1165            let highlighted_range = HighlightedRange {
1166                color,
1167                line_height: layout.position_map.line_height,
1168                corner_radius,
1169                start_y: content_origin.y()
1170                    + row_range.start as f32 * layout.position_map.line_height
1171                    - scroll_top,
1172                lines: row_range
1173                    .into_iter()
1174                    .map(|row| {
1175                        let line_layout =
1176                            &layout.position_map.line_layouts[(row - start_row) as usize].line;
1177                        HighlightedRangeLine {
1178                            start_x: if row == range.start.row() {
1179                                content_origin.x()
1180                                    + line_layout.x_for_index(range.start.column() as usize)
1181                                    - scroll_left
1182                            } else {
1183                                content_origin.x() - scroll_left
1184                            },
1185                            end_x: if row == range.end.row() {
1186                                content_origin.x()
1187                                    + line_layout.x_for_index(range.end.column() as usize)
1188                                    - scroll_left
1189                            } else {
1190                                content_origin.x() + line_layout.width() + line_end_overshoot
1191                                    - scroll_left
1192                            },
1193                        }
1194                    })
1195                    .collect(),
1196            };
1197
1198            highlighted_range.paint(bounds, scene);
1199        }
1200    }
1201
1202    fn paint_blocks(
1203        &mut self,
1204        scene: &mut SceneBuilder,
1205        bounds: RectF,
1206        visible_bounds: RectF,
1207        layout: &mut LayoutState,
1208        editor: &mut Editor,
1209        cx: &mut ViewContext<Editor>,
1210    ) {
1211        let scroll_position = layout.position_map.snapshot.scroll_position();
1212        let scroll_left = scroll_position.x() * layout.position_map.em_width;
1213        let scroll_top = scroll_position.y() * layout.position_map.line_height;
1214
1215        for block in &mut layout.blocks {
1216            let mut origin = bounds.origin()
1217                + vec2f(
1218                    0.,
1219                    block.row as f32 * layout.position_map.line_height - scroll_top,
1220                );
1221            if !matches!(block.style, BlockStyle::Sticky) {
1222                origin += vec2f(-scroll_left, 0.);
1223            }
1224            block
1225                .element
1226                .paint(scene, origin, visible_bounds, editor, cx);
1227        }
1228    }
1229
1230    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &ViewContext<Editor>) -> f32 {
1231        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
1232        let style = &self.style;
1233
1234        cx.text_layout_cache()
1235            .layout_str(
1236                "1".repeat(digit_count).as_str(),
1237                style.text.font_size,
1238                &[(
1239                    digit_count,
1240                    RunStyle {
1241                        font_id: style.text.font_id,
1242                        color: Color::black(),
1243                        underline: Default::default(),
1244                    },
1245                )],
1246            )
1247            .width()
1248    }
1249
1250    //Folds contained in a hunk are ignored apart from shrinking visual size
1251    //If a fold contains any hunks then that fold line is marked as modified
1252    fn layout_git_gutters(
1253        &self,
1254        display_rows: Range<u32>,
1255        snapshot: &EditorSnapshot,
1256    ) -> Vec<DisplayDiffHunk> {
1257        let buffer_snapshot = &snapshot.buffer_snapshot;
1258
1259        let buffer_start_row = DisplayPoint::new(display_rows.start, 0)
1260            .to_point(snapshot)
1261            .row;
1262        let buffer_end_row = DisplayPoint::new(display_rows.end, 0)
1263            .to_point(snapshot)
1264            .row;
1265
1266        buffer_snapshot
1267            .git_diff_hunks_in_range(buffer_start_row..buffer_end_row, false)
1268            .map(|hunk| diff_hunk_to_display(hunk, snapshot))
1269            .dedup()
1270            .collect()
1271    }
1272
1273    fn layout_line_numbers(
1274        &self,
1275        rows: Range<u32>,
1276        active_rows: &BTreeMap<u32, bool>,
1277        is_singleton: bool,
1278        snapshot: &EditorSnapshot,
1279        cx: &ViewContext<Editor>,
1280    ) -> (
1281        Vec<Option<text_layout::Line>>,
1282        Vec<Option<(FoldStatus, BufferRow, bool)>>,
1283    ) {
1284        let style = &self.style;
1285        let include_line_numbers = snapshot.mode == EditorMode::Full;
1286        let mut line_number_layouts = Vec::with_capacity(rows.len());
1287        let mut fold_statuses = Vec::with_capacity(rows.len());
1288        let mut line_number = String::new();
1289        for (ix, row) in snapshot
1290            .buffer_rows(rows.start)
1291            .take((rows.end - rows.start) as usize)
1292            .enumerate()
1293        {
1294            let display_row = rows.start + ix as u32;
1295            let (active, color) = if active_rows.contains_key(&display_row) {
1296                (true, style.line_number_active)
1297            } else {
1298                (false, style.line_number)
1299            };
1300            if let Some(buffer_row) = row {
1301                if include_line_numbers {
1302                    line_number.clear();
1303                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
1304                    line_number_layouts.push(Some(cx.text_layout_cache().layout_str(
1305                        &line_number,
1306                        style.text.font_size,
1307                        &[(
1308                            line_number.len(),
1309                            RunStyle {
1310                                font_id: style.text.font_id,
1311                                color,
1312                                underline: Default::default(),
1313                            },
1314                        )],
1315                    )));
1316                    fold_statuses.push(
1317                        is_singleton
1318                            .then(|| {
1319                                snapshot
1320                                    .fold_for_line(buffer_row)
1321                                    .map(|fold_status| (fold_status, buffer_row, active))
1322                            })
1323                            .flatten(),
1324                    )
1325                }
1326            } else {
1327                fold_statuses.push(None);
1328                line_number_layouts.push(None);
1329            }
1330        }
1331
1332        (line_number_layouts, fold_statuses)
1333    }
1334
1335    fn layout_lines(
1336        &mut self,
1337        rows: Range<u32>,
1338        line_number_layouts: &[Option<Line>],
1339        snapshot: &EditorSnapshot,
1340        cx: &ViewContext<Editor>,
1341    ) -> Vec<LineWithInvisibles> {
1342        if rows.start >= rows.end {
1343            return Vec::new();
1344        }
1345
1346        // When the editor is empty and unfocused, then show the placeholder.
1347        if snapshot.is_empty() {
1348            let placeholder_style = self
1349                .style
1350                .placeholder_text
1351                .as_ref()
1352                .unwrap_or(&self.style.text);
1353            let placeholder_text = snapshot.placeholder_text();
1354            let placeholder_lines = placeholder_text
1355                .as_ref()
1356                .map_or("", AsRef::as_ref)
1357                .split('\n')
1358                .skip(rows.start as usize)
1359                .chain(iter::repeat(""))
1360                .take(rows.len());
1361            placeholder_lines
1362                .map(|line| {
1363                    cx.text_layout_cache().layout_str(
1364                        line,
1365                        placeholder_style.font_size,
1366                        &[(
1367                            line.len(),
1368                            RunStyle {
1369                                font_id: placeholder_style.font_id,
1370                                color: placeholder_style.color,
1371                                underline: Default::default(),
1372                            },
1373                        )],
1374                    )
1375                })
1376                .map(|line| LineWithInvisibles {
1377                    line,
1378                    invisibles: Vec::new(),
1379                })
1380                .collect()
1381        } else {
1382            let style = &self.style;
1383            let chunks = snapshot
1384                .chunks(rows.clone(), true, Some(style.theme.suggestion))
1385                .map(|chunk| {
1386                    let mut highlight_style = chunk
1387                        .syntax_highlight_id
1388                        .and_then(|id| id.style(&style.syntax));
1389
1390                    if let Some(chunk_highlight) = chunk.highlight_style {
1391                        if let Some(highlight_style) = highlight_style.as_mut() {
1392                            highlight_style.highlight(chunk_highlight);
1393                        } else {
1394                            highlight_style = Some(chunk_highlight);
1395                        }
1396                    }
1397
1398                    let mut diagnostic_highlight = HighlightStyle::default();
1399
1400                    if chunk.is_unnecessary {
1401                        diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
1402                    }
1403
1404                    if let Some(severity) = chunk.diagnostic_severity {
1405                        // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
1406                        if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
1407                            let diagnostic_style = super::diagnostic_style(severity, true, style);
1408                            diagnostic_highlight.underline = Some(Underline {
1409                                color: Some(diagnostic_style.message.text.color),
1410                                thickness: 1.0.into(),
1411                                squiggly: true,
1412                            });
1413                        }
1414                    }
1415
1416                    if let Some(highlight_style) = highlight_style.as_mut() {
1417                        highlight_style.highlight(diagnostic_highlight);
1418                    } else {
1419                        highlight_style = Some(diagnostic_highlight);
1420                    }
1421
1422                    HighlightedChunk {
1423                        chunk: chunk.text,
1424                        style: highlight_style,
1425                        is_tab: chunk.is_tab,
1426                    }
1427                });
1428
1429            LineWithInvisibles::from_chunks(
1430                chunks,
1431                &style.text,
1432                cx.text_layout_cache(),
1433                cx.font_cache(),
1434                MAX_LINE_LEN,
1435                rows.len() as usize,
1436                line_number_layouts,
1437                snapshot.mode,
1438            )
1439        }
1440    }
1441
1442    #[allow(clippy::too_many_arguments)]
1443    fn layout_blocks(
1444        &mut self,
1445        rows: Range<u32>,
1446        snapshot: &EditorSnapshot,
1447        editor_width: f32,
1448        scroll_width: f32,
1449        gutter_padding: f32,
1450        gutter_width: f32,
1451        em_width: f32,
1452        text_x: f32,
1453        line_height: f32,
1454        style: &EditorStyle,
1455        line_layouts: &[LineWithInvisibles],
1456        include_root: bool,
1457        editor: &mut Editor,
1458        cx: &mut LayoutContext<Editor>,
1459    ) -> (f32, Vec<BlockLayout>) {
1460        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
1461        let scroll_x = snapshot.scroll_anchor.offset.x();
1462        let (fixed_blocks, non_fixed_blocks) = snapshot
1463            .blocks_in_range(rows.clone())
1464            .partition::<Vec<_>, _>(|(_, block)| match block {
1465                TransformBlock::ExcerptHeader { .. } => false,
1466                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
1467            });
1468        let mut render_block = |block: &TransformBlock, width: f32| {
1469            let mut element = match block {
1470                TransformBlock::Custom(block) => {
1471                    let align_to = block
1472                        .position()
1473                        .to_point(&snapshot.buffer_snapshot)
1474                        .to_display_point(snapshot);
1475                    let anchor_x = text_x
1476                        + if rows.contains(&align_to.row()) {
1477                            line_layouts[(align_to.row() - rows.start) as usize]
1478                                .line
1479                                .x_for_index(align_to.column() as usize)
1480                        } else {
1481                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache())
1482                                .x_for_index(align_to.column() as usize)
1483                        };
1484
1485                    block.render(&mut BlockContext {
1486                        view_context: cx,
1487                        anchor_x,
1488                        gutter_padding,
1489                        line_height,
1490                        scroll_x,
1491                        gutter_width,
1492                        em_width,
1493                    })
1494                }
1495                TransformBlock::ExcerptHeader {
1496                    id,
1497                    buffer,
1498                    range,
1499                    starts_new_buffer,
1500                    ..
1501                } => {
1502                    let id = *id;
1503                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
1504                        let jump_path = ProjectPath {
1505                            worktree_id: file.worktree_id(cx),
1506                            path: file.path.clone(),
1507                        };
1508                        let jump_anchor = range
1509                            .primary
1510                            .as_ref()
1511                            .map_or(range.context.start, |primary| primary.start);
1512                        let jump_position = language::ToPoint::to_point(&jump_anchor, buffer);
1513
1514                        enum JumpIcon {}
1515                        MouseEventHandler::<JumpIcon, _>::new(id.into(), cx, |state, _| {
1516                            let style = style.jump_icon.style_for(state, false);
1517                            Svg::new("icons/arrow_up_right_8.svg")
1518                                .with_color(style.color)
1519                                .constrained()
1520                                .with_width(style.icon_width)
1521                                .aligned()
1522                                .contained()
1523                                .with_style(style.container)
1524                                .constrained()
1525                                .with_width(style.button_width)
1526                                .with_height(style.button_width)
1527                        })
1528                        .with_cursor_style(CursorStyle::PointingHand)
1529                        .on_click(MouseButton::Left, move |_, editor, cx| {
1530                            if let Some(workspace) = editor
1531                                .workspace
1532                                .as_ref()
1533                                .and_then(|(workspace, _)| workspace.upgrade(cx))
1534                            {
1535                                workspace.update(cx, |workspace, cx| {
1536                                    Editor::jump(
1537                                        workspace,
1538                                        jump_path.clone(),
1539                                        jump_position,
1540                                        jump_anchor,
1541                                        cx,
1542                                    );
1543                                });
1544                            }
1545                        })
1546                        .with_tooltip::<JumpIcon>(
1547                            id.into(),
1548                            "Jump to Buffer".to_string(),
1549                            Some(Box::new(crate::OpenExcerpts)),
1550                            tooltip_style.clone(),
1551                            cx,
1552                        )
1553                        .aligned()
1554                        .flex_float()
1555                    });
1556
1557                    if *starts_new_buffer {
1558                        let style = &self.style.diagnostic_path_header;
1559                        let font_size =
1560                            (style.text_scale_factor * self.style.text.font_size).round();
1561
1562                        let path = buffer.resolve_file_path(cx, include_root);
1563                        let mut filename = None;
1564                        let mut parent_path = None;
1565                        // Can't use .and_then() because `.file_name()` and `.parent()` return references :(
1566                        if let Some(path) = path {
1567                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1568                            parent_path =
1569                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1570                        }
1571
1572                        Flex::row()
1573                            .with_child(
1574                                Label::new(
1575                                    filename.unwrap_or_else(|| "untitled".to_string()),
1576                                    style.filename.text.clone().with_font_size(font_size),
1577                                )
1578                                .contained()
1579                                .with_style(style.filename.container)
1580                                .aligned(),
1581                            )
1582                            .with_children(parent_path.map(|path| {
1583                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1584                                    .contained()
1585                                    .with_style(style.path.container)
1586                                    .aligned()
1587                            }))
1588                            .with_children(jump_icon)
1589                            .contained()
1590                            .with_style(style.container)
1591                            .with_padding_left(gutter_padding)
1592                            .with_padding_right(gutter_padding)
1593                            .expanded()
1594                            .into_any_named("path header block")
1595                    } else {
1596                        let text_style = self.style.text.clone();
1597                        Flex::row()
1598                            .with_child(Label::new("⋯", text_style))
1599                            .with_children(jump_icon)
1600                            .contained()
1601                            .with_padding_left(gutter_padding)
1602                            .with_padding_right(gutter_padding)
1603                            .expanded()
1604                            .into_any_named("collapsed context")
1605                    }
1606                }
1607            };
1608
1609            element.layout(
1610                SizeConstraint {
1611                    min: Vector2F::zero(),
1612                    max: vec2f(width, block.height() as f32 * line_height),
1613                },
1614                editor,
1615                cx,
1616            );
1617            element
1618        };
1619
1620        let mut fixed_block_max_width = 0f32;
1621        let mut blocks = Vec::new();
1622        for (row, block) in fixed_blocks {
1623            let element = render_block(block, f32::INFINITY);
1624            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1625            blocks.push(BlockLayout {
1626                row,
1627                element,
1628                style: BlockStyle::Fixed,
1629            });
1630        }
1631        for (row, block) in non_fixed_blocks {
1632            let style = match block {
1633                TransformBlock::Custom(block) => block.style(),
1634                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1635            };
1636            let width = match style {
1637                BlockStyle::Sticky => editor_width,
1638                BlockStyle::Flex => editor_width
1639                    .max(fixed_block_max_width)
1640                    .max(gutter_width + scroll_width),
1641                BlockStyle::Fixed => unreachable!(),
1642            };
1643            let element = render_block(block, width);
1644            blocks.push(BlockLayout {
1645                row,
1646                element,
1647                style,
1648            });
1649        }
1650        (
1651            scroll_width.max(fixed_block_max_width - gutter_width),
1652            blocks,
1653        )
1654    }
1655}
1656
1657struct HighlightedChunk<'a> {
1658    chunk: &'a str,
1659    style: Option<HighlightStyle>,
1660    is_tab: bool,
1661}
1662
1663#[derive(Debug)]
1664pub struct LineWithInvisibles {
1665    pub line: Line,
1666    invisibles: Vec<Invisible>,
1667}
1668
1669impl LineWithInvisibles {
1670    fn from_chunks<'a>(
1671        chunks: impl Iterator<Item = HighlightedChunk<'a>>,
1672        text_style: &TextStyle,
1673        text_layout_cache: &TextLayoutCache,
1674        font_cache: &Arc<FontCache>,
1675        max_line_len: usize,
1676        max_line_count: usize,
1677        line_number_layouts: &[Option<Line>],
1678        editor_mode: EditorMode,
1679    ) -> Vec<Self> {
1680        let mut layouts = Vec::with_capacity(max_line_count);
1681        let mut line = String::new();
1682        let mut invisibles = Vec::new();
1683        let mut styles = Vec::new();
1684        let mut non_whitespace_added = false;
1685        let mut row = 0;
1686        let mut line_exceeded_max_len = false;
1687        for highlighted_chunk in chunks.chain([HighlightedChunk {
1688            chunk: "\n",
1689            style: None,
1690            is_tab: false,
1691        }]) {
1692            for (ix, mut line_chunk) in highlighted_chunk.chunk.split('\n').enumerate() {
1693                if ix > 0 {
1694                    layouts.push(Self {
1695                        line: text_layout_cache.layout_str(&line, text_style.font_size, &styles),
1696                        invisibles: invisibles.drain(..).collect(),
1697                    });
1698
1699                    line.clear();
1700                    styles.clear();
1701                    row += 1;
1702                    line_exceeded_max_len = false;
1703                    non_whitespace_added = false;
1704                    if row == max_line_count {
1705                        return layouts;
1706                    }
1707                }
1708
1709                if !line_chunk.is_empty() && !line_exceeded_max_len {
1710                    let text_style = if let Some(style) = highlighted_chunk.style {
1711                        text_style
1712                            .clone()
1713                            .highlight(style, font_cache)
1714                            .map(Cow::Owned)
1715                            .unwrap_or_else(|_| Cow::Borrowed(text_style))
1716                    } else {
1717                        Cow::Borrowed(text_style)
1718                    };
1719
1720                    if line.len() + line_chunk.len() > max_line_len {
1721                        let mut chunk_len = max_line_len - line.len();
1722                        while !line_chunk.is_char_boundary(chunk_len) {
1723                            chunk_len -= 1;
1724                        }
1725                        line_chunk = &line_chunk[..chunk_len];
1726                        line_exceeded_max_len = true;
1727                    }
1728
1729                    styles.push((
1730                        line_chunk.len(),
1731                        RunStyle {
1732                            font_id: text_style.font_id,
1733                            color: text_style.color,
1734                            underline: text_style.underline,
1735                        },
1736                    ));
1737
1738                    if editor_mode == EditorMode::Full {
1739                        // Line wrap pads its contents with fake whitespaces,
1740                        // avoid printing them
1741                        let inside_wrapped_string = line_number_layouts
1742                            .get(row)
1743                            .and_then(|layout| layout.as_ref())
1744                            .is_none();
1745                        if highlighted_chunk.is_tab {
1746                            if non_whitespace_added || !inside_wrapped_string {
1747                                invisibles.push(Invisible::Tab {
1748                                    line_start_offset: line.len(),
1749                                });
1750                            }
1751                        } else {
1752                            invisibles.extend(
1753                                line_chunk
1754                                    .chars()
1755                                    .enumerate()
1756                                    .filter(|(_, line_char)| {
1757                                        let is_whitespace = line_char.is_whitespace();
1758                                        non_whitespace_added |= !is_whitespace;
1759                                        is_whitespace
1760                                            && (non_whitespace_added || !inside_wrapped_string)
1761                                    })
1762                                    .map(|(whitespace_index, _)| Invisible::Whitespace {
1763                                        line_offset: line.len() + whitespace_index,
1764                                    }),
1765                            )
1766                        }
1767                    }
1768
1769                    line.push_str(line_chunk);
1770                }
1771            }
1772        }
1773
1774        layouts
1775    }
1776
1777    fn draw(
1778        &self,
1779        layout: &LayoutState,
1780        row: u32,
1781        scroll_top: f32,
1782        scene: &mut SceneBuilder,
1783        content_origin: Vector2F,
1784        scroll_left: f32,
1785        visible_text_bounds: RectF,
1786        cx: &mut ViewContext<Editor>,
1787        selection_ranges: &[Range<DisplayPoint>],
1788        visible_bounds: RectF,
1789    ) {
1790        let line_height = layout.position_map.line_height;
1791        let line_y = row as f32 * line_height - scroll_top;
1792
1793        self.line.paint(
1794            scene,
1795            content_origin + vec2f(-scroll_left, line_y),
1796            visible_text_bounds,
1797            line_height,
1798            cx,
1799        );
1800
1801        self.draw_invisibles(
1802            cx,
1803            &selection_ranges,
1804            layout,
1805            content_origin,
1806            scroll_left,
1807            line_y,
1808            row,
1809            scene,
1810            visible_bounds,
1811            line_height,
1812        );
1813    }
1814
1815    fn draw_invisibles(
1816        &self,
1817        cx: &mut ViewContext<Editor>,
1818        selection_ranges: &[Range<DisplayPoint>],
1819        layout: &LayoutState,
1820        content_origin: Vector2F,
1821        scroll_left: f32,
1822        line_y: f32,
1823        row: u32,
1824        scene: &mut SceneBuilder,
1825        visible_bounds: RectF,
1826        line_height: f32,
1827    ) {
1828        let settings = cx.global::<Settings>();
1829        let allowed_invisibles_regions = match settings
1830            .editor_overrides
1831            .show_whitespaces
1832            .or(settings.editor_defaults.show_whitespaces)
1833            .unwrap_or_default()
1834        {
1835            ShowWhitespaces::None => return,
1836            ShowWhitespaces::Selection => Some(selection_ranges),
1837            ShowWhitespaces::All => None,
1838        };
1839
1840        for invisible in &self.invisibles {
1841            let (&token_offset, invisible_symbol) = match invisible {
1842                Invisible::Tab { line_start_offset } => (line_start_offset, &layout.tab_invisible),
1843                Invisible::Whitespace { line_offset } => (line_offset, &layout.space_invisible),
1844            };
1845
1846            let x_offset = self.line.x_for_index(token_offset);
1847            let invisible_offset =
1848                (layout.position_map.em_width - invisible_symbol.width()).max(0.0) / 2.0;
1849            let origin = content_origin + vec2f(-scroll_left + x_offset + invisible_offset, line_y);
1850
1851            if let Some(allowed_regions) = allowed_invisibles_regions {
1852                let invisible_point = DisplayPoint::new(row, token_offset as u32);
1853                if !allowed_regions
1854                    .iter()
1855                    .any(|region| region.start <= invisible_point && invisible_point < region.end)
1856                {
1857                    continue;
1858                }
1859            }
1860            invisible_symbol.paint(scene, origin, visible_bounds, line_height, cx);
1861        }
1862    }
1863}
1864
1865#[derive(Debug, Clone, Copy, PartialEq, Eq)]
1866enum Invisible {
1867    Tab { line_start_offset: usize },
1868    Whitespace { line_offset: usize },
1869}
1870
1871impl Element<Editor> for EditorElement {
1872    type LayoutState = LayoutState;
1873    type PaintState = ();
1874
1875    fn layout(
1876        &mut self,
1877        constraint: SizeConstraint,
1878        editor: &mut Editor,
1879        cx: &mut LayoutContext<Editor>,
1880    ) -> (Vector2F, Self::LayoutState) {
1881        let mut size = constraint.max;
1882        if size.x().is_infinite() {
1883            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1884        }
1885
1886        let snapshot = editor.snapshot(cx);
1887        let style = self.style.clone();
1888        let line_height = style.text.line_height(cx.font_cache());
1889
1890        let gutter_padding;
1891        let gutter_width;
1892        let gutter_margin;
1893        if snapshot.mode == EditorMode::Full {
1894            let em_width = style.text.em_width(cx.font_cache());
1895            gutter_padding = (em_width * style.gutter_padding_factor).round();
1896            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1897            gutter_margin = -style.text.descent(cx.font_cache());
1898        } else {
1899            gutter_padding = 0.0;
1900            gutter_width = 0.0;
1901            gutter_margin = 0.0;
1902        };
1903
1904        let text_width = size.x() - gutter_width;
1905        let em_width = style.text.em_width(cx.font_cache());
1906        let em_advance = style.text.em_advance(cx.font_cache());
1907        let overscroll = vec2f(em_width, 0.);
1908        let snapshot = {
1909            editor.set_visible_line_count(size.y() / line_height);
1910
1911            let editor_width = text_width - gutter_margin - overscroll.x() - em_width;
1912            let wrap_width = match editor.soft_wrap_mode(cx) {
1913                SoftWrap::None => (MAX_LINE_LEN / 2) as f32 * em_advance,
1914                SoftWrap::EditorWidth => editor_width,
1915                SoftWrap::Column(column) => editor_width.min(column as f32 * em_advance),
1916            };
1917
1918            if editor.set_wrap_width(Some(wrap_width), cx) {
1919                editor.snapshot(cx)
1920            } else {
1921                snapshot
1922            }
1923        };
1924
1925        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1926        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1927            size.set_y(
1928                scroll_height
1929                    .min(constraint.max_along(Axis::Vertical))
1930                    .max(constraint.min_along(Axis::Vertical))
1931                    .min(line_height * max_lines as f32),
1932            )
1933        } else if let EditorMode::SingleLine = snapshot.mode {
1934            size.set_y(
1935                line_height
1936                    .min(constraint.max_along(Axis::Vertical))
1937                    .max(constraint.min_along(Axis::Vertical)),
1938            )
1939        } else if size.y().is_infinite() {
1940            size.set_y(scroll_height);
1941        }
1942        let gutter_size = vec2f(gutter_width, size.y());
1943        let text_size = vec2f(text_width, size.y());
1944
1945        let autoscroll_horizontally = editor.autoscroll_vertically(size.y(), line_height, cx);
1946        let mut snapshot = editor.snapshot(cx);
1947
1948        let scroll_position = snapshot.scroll_position();
1949        // The scroll position is a fractional point, the whole number of which represents
1950        // the top of the window in terms of display rows.
1951        let start_row = scroll_position.y() as u32;
1952        let height_in_lines = size.y() / line_height;
1953        let max_row = snapshot.max_point().row();
1954
1955        // Add 1 to ensure selections bleed off screen
1956        let end_row = 1 + cmp::min(
1957            (scroll_position.y() + height_in_lines).ceil() as u32,
1958            max_row,
1959        );
1960
1961        let start_anchor = if start_row == 0 {
1962            Anchor::min()
1963        } else {
1964            snapshot
1965                .buffer_snapshot
1966                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1967        };
1968        let end_anchor = if end_row > max_row {
1969            Anchor::max()
1970        } else {
1971            snapshot
1972                .buffer_snapshot
1973                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1974        };
1975
1976        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1977        let mut active_rows = BTreeMap::new();
1978        let mut fold_ranges = Vec::new();
1979        let is_singleton = editor.is_singleton(cx);
1980
1981        let highlighted_rows = editor.highlighted_rows();
1982        let theme = cx.global::<Settings>().theme.as_ref();
1983        let highlighted_ranges = editor.background_highlights_in_range(
1984            start_anchor..end_anchor,
1985            &snapshot.display_snapshot,
1986            theme,
1987        );
1988
1989        fold_ranges.extend(
1990            snapshot
1991                .folds_in_range(start_anchor..end_anchor)
1992                .map(|anchor| {
1993                    let start = anchor.start.to_point(&snapshot.buffer_snapshot);
1994                    (
1995                        start.row,
1996                        start.to_display_point(&snapshot.display_snapshot)
1997                            ..anchor.end.to_display_point(&snapshot),
1998                    )
1999                }),
2000        );
2001
2002        let mut remote_selections = HashMap::default();
2003        for (replica_id, line_mode, cursor_shape, selection) in snapshot
2004            .buffer_snapshot
2005            .remote_selections_in_range(&(start_anchor..end_anchor))
2006        {
2007            // The local selections match the leader's selections.
2008            if Some(replica_id) == editor.leader_replica_id {
2009                continue;
2010            }
2011            remote_selections
2012                .entry(replica_id)
2013                .or_insert(Vec::new())
2014                .push(SelectionLayout::new(
2015                    selection,
2016                    line_mode,
2017                    cursor_shape,
2018                    &snapshot.display_snapshot,
2019                ));
2020        }
2021        selections.extend(remote_selections);
2022
2023        if editor.show_local_selections {
2024            let mut local_selections = editor
2025                .selections
2026                .disjoint_in_range(start_anchor..end_anchor, cx);
2027            local_selections.extend(editor.selections.pending(cx));
2028            for selection in &local_selections {
2029                let is_empty = selection.start == selection.end;
2030                let selection_start = snapshot.prev_line_boundary(selection.start).1;
2031                let selection_end = snapshot.next_line_boundary(selection.end).1;
2032                for row in cmp::max(selection_start.row(), start_row)
2033                    ..=cmp::min(selection_end.row(), end_row)
2034                {
2035                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
2036                    *contains_non_empty_selection |= !is_empty;
2037                }
2038            }
2039
2040            // Render the local selections in the leader's color when following.
2041            let local_replica_id = editor
2042                .leader_replica_id
2043                .unwrap_or_else(|| editor.replica_id(cx));
2044
2045            selections.push((
2046                local_replica_id,
2047                local_selections
2048                    .into_iter()
2049                    .map(|selection| {
2050                        SelectionLayout::new(
2051                            selection,
2052                            editor.selections.line_mode,
2053                            editor.cursor_shape,
2054                            &snapshot.display_snapshot,
2055                        )
2056                    })
2057                    .collect(),
2058            ));
2059        }
2060
2061        let show_scrollbars = match cx.global::<Settings>().show_scrollbars {
2062            settings::ShowScrollbars::Auto => {
2063                snapshot.has_scrollbar_info() || editor.scroll_manager.scrollbars_visible()
2064            }
2065            settings::ShowScrollbars::System => editor.scroll_manager.scrollbars_visible(),
2066            settings::ShowScrollbars::Always => true,
2067        };
2068
2069        let include_root = editor
2070            .project
2071            .as_ref()
2072            .map(|project| project.read(cx).visible_worktrees(cx).count() > 1)
2073            .unwrap_or_default();
2074
2075        let fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)> = fold_ranges
2076            .into_iter()
2077            .map(|(id, fold)| {
2078                let color = self
2079                    .style
2080                    .folds
2081                    .ellipses
2082                    .background
2083                    .style_for(&mut cx.mouse_state::<FoldMarkers>(id as usize), false)
2084                    .color;
2085
2086                (id, fold, color)
2087            })
2088            .collect();
2089
2090        let (line_number_layouts, fold_statuses) = self.layout_line_numbers(
2091            start_row..end_row,
2092            &active_rows,
2093            is_singleton,
2094            &snapshot,
2095            cx,
2096        );
2097
2098        let display_hunks = self.layout_git_gutters(start_row..end_row, &snapshot);
2099
2100        let scrollbar_row_range = scroll_position.y()..(scroll_position.y() + height_in_lines);
2101
2102        let mut max_visible_line_width = 0.0;
2103        let line_layouts =
2104            self.layout_lines(start_row..end_row, &line_number_layouts, &snapshot, cx);
2105        for line_with_invisibles in &line_layouts {
2106            if line_with_invisibles.line.width() > max_visible_line_width {
2107                max_visible_line_width = line_with_invisibles.line.width();
2108            }
2109        }
2110
2111        let style = self.style.clone();
2112        let longest_line_width = layout_line(
2113            snapshot.longest_row(),
2114            &snapshot,
2115            &style,
2116            cx.text_layout_cache(),
2117        )
2118        .width();
2119        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
2120        let em_width = style.text.em_width(cx.font_cache());
2121        let (scroll_width, blocks) = self.layout_blocks(
2122            start_row..end_row,
2123            &snapshot,
2124            size.x(),
2125            scroll_width,
2126            gutter_padding,
2127            gutter_width,
2128            em_width,
2129            gutter_width + gutter_margin,
2130            line_height,
2131            &style,
2132            &line_layouts,
2133            include_root,
2134            editor,
2135            cx,
2136        );
2137
2138        let scroll_max = vec2f(
2139            ((scroll_width - text_size.x()) / em_width).max(0.0),
2140            max_row as f32,
2141        );
2142
2143        let clamped = editor.scroll_manager.clamp_scroll_left(scroll_max.x());
2144
2145        let autoscrolled = if autoscroll_horizontally {
2146            editor.autoscroll_horizontally(
2147                start_row,
2148                text_size.x(),
2149                scroll_width,
2150                em_width,
2151                &line_layouts,
2152                cx,
2153            )
2154        } else {
2155            false
2156        };
2157
2158        if clamped || autoscrolled {
2159            snapshot = editor.snapshot(cx);
2160        }
2161
2162        let newest_selection_head = editor
2163            .selections
2164            .newest::<usize>(cx)
2165            .head()
2166            .to_display_point(&snapshot);
2167        let style = editor.style(cx);
2168
2169        let mut context_menu = None;
2170        let mut code_actions_indicator = None;
2171        if (start_row..end_row).contains(&newest_selection_head.row()) {
2172            if editor.context_menu_visible() {
2173                context_menu = editor.render_context_menu(newest_selection_head, style.clone(), cx);
2174            }
2175
2176            let active = matches!(
2177                editor.context_menu,
2178                Some(crate::ContextMenu::CodeActions(_))
2179            );
2180
2181            code_actions_indicator = editor
2182                .render_code_actions_indicator(&style, active, cx)
2183                .map(|indicator| (newest_selection_head.row(), indicator));
2184        }
2185
2186        let visible_rows = start_row..start_row + line_layouts.len() as u32;
2187        let mut hover = editor
2188            .hover_state
2189            .render(&snapshot, &style, visible_rows, cx);
2190        let mode = editor.mode;
2191
2192        let mut fold_indicators = editor.render_fold_indicators(
2193            fold_statuses,
2194            &style,
2195            editor.gutter_hovered,
2196            line_height,
2197            gutter_margin,
2198            cx,
2199        );
2200
2201        if let Some((_, context_menu)) = context_menu.as_mut() {
2202            context_menu.layout(
2203                SizeConstraint {
2204                    min: Vector2F::zero(),
2205                    max: vec2f(
2206                        cx.window_size().x() * 0.7,
2207                        (12. * line_height).min((size.y() - line_height) / 2.),
2208                    ),
2209                },
2210                editor,
2211                cx,
2212            );
2213        }
2214
2215        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
2216            indicator.layout(
2217                SizeConstraint::strict_along(
2218                    Axis::Vertical,
2219                    line_height * style.code_actions.vertical_scale,
2220                ),
2221                editor,
2222                cx,
2223            );
2224        }
2225
2226        for fold_indicator in fold_indicators.iter_mut() {
2227            if let Some(indicator) = fold_indicator.as_mut() {
2228                indicator.layout(
2229                    SizeConstraint::strict_along(
2230                        Axis::Vertical,
2231                        line_height * style.code_actions.vertical_scale,
2232                    ),
2233                    editor,
2234                    cx,
2235                );
2236            }
2237        }
2238
2239        if let Some((_, hover_popovers)) = hover.as_mut() {
2240            for hover_popover in hover_popovers.iter_mut() {
2241                hover_popover.layout(
2242                    SizeConstraint {
2243                        min: Vector2F::zero(),
2244                        max: vec2f(
2245                            (120. * em_width) // Default size
2246                                .min(size.x() / 2.) // Shrink to half of the editor width
2247                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
2248                            (16. * line_height) // Default size
2249                                .min(size.y() / 2.) // Shrink to half of the editor height
2250                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
2251                        ),
2252                    },
2253                    editor,
2254                    cx,
2255                );
2256            }
2257        }
2258
2259        let invisible_symbol_font_size = self.style.text.font_size / 2.0;
2260        let invisible_symbol_style = RunStyle {
2261            color: self.style.whitespace,
2262            font_id: self.style.text.font_id,
2263            underline: Default::default(),
2264        };
2265
2266        (
2267            size,
2268            LayoutState {
2269                mode,
2270                position_map: Arc::new(PositionMap {
2271                    size,
2272                    scroll_max,
2273                    line_layouts,
2274                    line_height,
2275                    em_width,
2276                    em_advance,
2277                    snapshot,
2278                }),
2279                visible_display_row_range: start_row..end_row,
2280                gutter_size,
2281                gutter_padding,
2282                text_size,
2283                scrollbar_row_range,
2284                show_scrollbars,
2285                max_row,
2286                gutter_margin,
2287                active_rows,
2288                highlighted_rows,
2289                highlighted_ranges,
2290                fold_ranges,
2291                line_number_layouts,
2292                display_hunks,
2293                blocks,
2294                selections,
2295                context_menu,
2296                code_actions_indicator,
2297                fold_indicators,
2298                tab_invisible: cx.text_layout_cache().layout_str(
2299                    "→",
2300                    invisible_symbol_font_size,
2301                    &[("→".len(), invisible_symbol_style)],
2302                ),
2303                space_invisible: cx.text_layout_cache().layout_str(
2304                    "•",
2305                    invisible_symbol_font_size,
2306                    &[("•".len(), invisible_symbol_style)],
2307                ),
2308                hover_popovers: hover,
2309            },
2310        )
2311    }
2312
2313    fn paint(
2314        &mut self,
2315        scene: &mut SceneBuilder,
2316        bounds: RectF,
2317        visible_bounds: RectF,
2318        layout: &mut Self::LayoutState,
2319        editor: &mut Editor,
2320        cx: &mut ViewContext<Editor>,
2321    ) -> Self::PaintState {
2322        let visible_bounds = bounds.intersection(visible_bounds).unwrap_or_default();
2323        scene.push_layer(Some(visible_bounds));
2324
2325        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
2326        let text_bounds = RectF::new(
2327            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2328            layout.text_size,
2329        );
2330
2331        Self::attach_mouse_handlers(
2332            scene,
2333            &layout.position_map,
2334            layout.hover_popovers.is_some(),
2335            visible_bounds,
2336            text_bounds,
2337            gutter_bounds,
2338            bounds,
2339            cx,
2340        );
2341
2342        self.paint_background(scene, gutter_bounds, text_bounds, layout);
2343        if layout.gutter_size.x() > 0. {
2344            self.paint_gutter(scene, gutter_bounds, visible_bounds, layout, editor, cx);
2345        }
2346        self.paint_text(scene, text_bounds, visible_bounds, layout, editor, cx);
2347
2348        scene.push_layer(Some(bounds));
2349        if !layout.blocks.is_empty() {
2350            self.paint_blocks(scene, bounds, visible_bounds, layout, editor, cx);
2351        }
2352        self.paint_scrollbar(scene, bounds, layout, cx);
2353        scene.pop_layer();
2354
2355        scene.pop_layer();
2356    }
2357
2358    fn rect_for_text_range(
2359        &self,
2360        range_utf16: Range<usize>,
2361        bounds: RectF,
2362        _: RectF,
2363        layout: &Self::LayoutState,
2364        _: &Self::PaintState,
2365        _: &Editor,
2366        _: &ViewContext<Editor>,
2367    ) -> Option<RectF> {
2368        let text_bounds = RectF::new(
2369            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2370            layout.text_size,
2371        );
2372        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
2373        let scroll_position = layout.position_map.snapshot.scroll_position();
2374        let start_row = scroll_position.y() as u32;
2375        let scroll_top = scroll_position.y() * layout.position_map.line_height;
2376        let scroll_left = scroll_position.x() * layout.position_map.em_width;
2377
2378        let range_start = OffsetUtf16(range_utf16.start)
2379            .to_display_point(&layout.position_map.snapshot.display_snapshot);
2380        if range_start.row() < start_row {
2381            return None;
2382        }
2383
2384        let line = &layout
2385            .position_map
2386            .line_layouts
2387            .get((range_start.row() - start_row) as usize)?
2388            .line;
2389        let range_start_x = line.x_for_index(range_start.column() as usize);
2390        let range_start_y = range_start.row() as f32 * layout.position_map.line_height;
2391        Some(RectF::new(
2392            content_origin
2393                + vec2f(
2394                    range_start_x,
2395                    range_start_y + layout.position_map.line_height,
2396                )
2397                - vec2f(scroll_left, scroll_top),
2398            vec2f(
2399                layout.position_map.em_width,
2400                layout.position_map.line_height,
2401            ),
2402        ))
2403    }
2404
2405    fn debug(
2406        &self,
2407        bounds: RectF,
2408        _: &Self::LayoutState,
2409        _: &Self::PaintState,
2410        _: &Editor,
2411        _: &ViewContext<Editor>,
2412    ) -> json::Value {
2413        json!({
2414            "type": "BufferElement",
2415            "bounds": bounds.to_json()
2416        })
2417    }
2418}
2419
2420type BufferRow = u32;
2421
2422pub struct LayoutState {
2423    position_map: Arc<PositionMap>,
2424    gutter_size: Vector2F,
2425    gutter_padding: f32,
2426    gutter_margin: f32,
2427    text_size: Vector2F,
2428    mode: EditorMode,
2429    visible_display_row_range: Range<u32>,
2430    active_rows: BTreeMap<u32, bool>,
2431    highlighted_rows: Option<Range<u32>>,
2432    line_number_layouts: Vec<Option<text_layout::Line>>,
2433    display_hunks: Vec<DisplayDiffHunk>,
2434    blocks: Vec<BlockLayout>,
2435    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
2436    fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)>,
2437    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
2438    scrollbar_row_range: Range<f32>,
2439    show_scrollbars: bool,
2440    max_row: u32,
2441    context_menu: Option<(DisplayPoint, AnyElement<Editor>)>,
2442    code_actions_indicator: Option<(u32, AnyElement<Editor>)>,
2443    hover_popovers: Option<(DisplayPoint, Vec<AnyElement<Editor>>)>,
2444    fold_indicators: Vec<Option<AnyElement<Editor>>>,
2445    tab_invisible: Line,
2446    space_invisible: Line,
2447}
2448
2449struct PositionMap {
2450    size: Vector2F,
2451    line_height: f32,
2452    scroll_max: Vector2F,
2453    em_width: f32,
2454    em_advance: f32,
2455    line_layouts: Vec<LineWithInvisibles>,
2456    snapshot: EditorSnapshot,
2457}
2458
2459impl PositionMap {
2460    /// Returns two display points:
2461    /// 1. The nearest *valid* position in the editor
2462    /// 2. An unclipped, potentially *invalid* position that maps directly to
2463    ///    the given pixel position.
2464    fn point_for_position(
2465        &self,
2466        text_bounds: RectF,
2467        position: Vector2F,
2468    ) -> (DisplayPoint, DisplayPoint) {
2469        let scroll_position = self.snapshot.scroll_position();
2470        let position = position - text_bounds.origin();
2471        let y = position.y().max(0.0).min(self.size.y());
2472        let x = position.x() + (scroll_position.x() * self.em_width);
2473        let row = (y / self.line_height + scroll_position.y()) as u32;
2474        let (column, x_overshoot) = if let Some(line) = self
2475            .line_layouts
2476            .get(row as usize - scroll_position.y() as usize)
2477            .map(|line_with_spaces| &line_with_spaces.line)
2478        {
2479            if let Some(ix) = line.index_for_x(x) {
2480                (ix as u32, 0.0)
2481            } else {
2482                (line.len() as u32, 0f32.max(x - line.width()))
2483            }
2484        } else {
2485            (0, x)
2486        };
2487
2488        let mut target_point = DisplayPoint::new(row, column);
2489        let point = self.snapshot.clip_point(target_point, Bias::Left);
2490        *target_point.column_mut() += (x_overshoot / self.em_advance) as u32;
2491
2492        (point, target_point)
2493    }
2494}
2495
2496struct BlockLayout {
2497    row: u32,
2498    element: AnyElement<Editor>,
2499    style: BlockStyle,
2500}
2501
2502fn layout_line(
2503    row: u32,
2504    snapshot: &EditorSnapshot,
2505    style: &EditorStyle,
2506    layout_cache: &TextLayoutCache,
2507) -> text_layout::Line {
2508    let mut line = snapshot.line(row);
2509
2510    if line.len() > MAX_LINE_LEN {
2511        let mut len = MAX_LINE_LEN;
2512        while !line.is_char_boundary(len) {
2513            len -= 1;
2514        }
2515
2516        line.truncate(len);
2517    }
2518
2519    layout_cache.layout_str(
2520        &line,
2521        style.text.font_size,
2522        &[(
2523            snapshot.line_len(row) as usize,
2524            RunStyle {
2525                font_id: style.text.font_id,
2526                color: Color::black(),
2527                underline: Default::default(),
2528            },
2529        )],
2530    )
2531}
2532
2533#[derive(Debug)]
2534pub struct Cursor {
2535    origin: Vector2F,
2536    block_width: f32,
2537    line_height: f32,
2538    color: Color,
2539    shape: CursorShape,
2540    block_text: Option<Line>,
2541}
2542
2543impl Cursor {
2544    pub fn new(
2545        origin: Vector2F,
2546        block_width: f32,
2547        line_height: f32,
2548        color: Color,
2549        shape: CursorShape,
2550        block_text: Option<Line>,
2551    ) -> Cursor {
2552        Cursor {
2553            origin,
2554            block_width,
2555            line_height,
2556            color,
2557            shape,
2558            block_text,
2559        }
2560    }
2561
2562    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
2563        RectF::new(
2564            self.origin + origin,
2565            vec2f(self.block_width, self.line_height),
2566        )
2567    }
2568
2569    pub fn paint(&self, scene: &mut SceneBuilder, origin: Vector2F, cx: &mut WindowContext) {
2570        let bounds = match self.shape {
2571            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
2572            CursorShape::Block | CursorShape::Hollow => RectF::new(
2573                self.origin + origin,
2574                vec2f(self.block_width, self.line_height),
2575            ),
2576            CursorShape::Underscore => RectF::new(
2577                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
2578                vec2f(self.block_width, 2.0),
2579            ),
2580        };
2581
2582        //Draw background or border quad
2583        if matches!(self.shape, CursorShape::Hollow) {
2584            scene.push_quad(Quad {
2585                bounds,
2586                background: None,
2587                border: Border::all(1., self.color),
2588                corner_radius: 0.,
2589            });
2590        } else {
2591            scene.push_quad(Quad {
2592                bounds,
2593                background: Some(self.color),
2594                border: Default::default(),
2595                corner_radius: 0.,
2596            });
2597        }
2598
2599        if let Some(block_text) = &self.block_text {
2600            block_text.paint(scene, self.origin + origin, bounds, self.line_height, cx);
2601        }
2602    }
2603
2604    pub fn shape(&self) -> CursorShape {
2605        self.shape
2606    }
2607}
2608
2609#[derive(Debug)]
2610pub struct HighlightedRange {
2611    pub start_y: f32,
2612    pub line_height: f32,
2613    pub lines: Vec<HighlightedRangeLine>,
2614    pub color: Color,
2615    pub corner_radius: f32,
2616}
2617
2618#[derive(Debug)]
2619pub struct HighlightedRangeLine {
2620    pub start_x: f32,
2621    pub end_x: f32,
2622}
2623
2624impl HighlightedRange {
2625    pub fn paint(&self, bounds: RectF, scene: &mut SceneBuilder) {
2626        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
2627            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
2628            self.paint_lines(
2629                self.start_y + self.line_height,
2630                &self.lines[1..],
2631                bounds,
2632                scene,
2633            );
2634        } else {
2635            self.paint_lines(self.start_y, &self.lines, bounds, scene);
2636        }
2637    }
2638
2639    fn paint_lines(
2640        &self,
2641        start_y: f32,
2642        lines: &[HighlightedRangeLine],
2643        bounds: RectF,
2644        scene: &mut SceneBuilder,
2645    ) {
2646        if lines.is_empty() {
2647            return;
2648        }
2649
2650        let mut path = PathBuilder::new();
2651        let first_line = lines.first().unwrap();
2652        let last_line = lines.last().unwrap();
2653
2654        let first_top_left = vec2f(first_line.start_x, start_y);
2655        let first_top_right = vec2f(first_line.end_x, start_y);
2656
2657        let curve_height = vec2f(0., self.corner_radius);
2658        let curve_width = |start_x: f32, end_x: f32| {
2659            let max = (end_x - start_x) / 2.;
2660            let width = if max < self.corner_radius {
2661                max
2662            } else {
2663                self.corner_radius
2664            };
2665
2666            vec2f(width, 0.)
2667        };
2668
2669        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
2670        path.reset(first_top_right - top_curve_width);
2671        path.curve_to(first_top_right + curve_height, first_top_right);
2672
2673        let mut iter = lines.iter().enumerate().peekable();
2674        while let Some((ix, line)) = iter.next() {
2675            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
2676
2677            if let Some((_, next_line)) = iter.peek() {
2678                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
2679
2680                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
2681                    Ordering::Equal => {
2682                        path.line_to(bottom_right);
2683                    }
2684                    Ordering::Less => {
2685                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
2686                        path.line_to(bottom_right - curve_height);
2687                        if self.corner_radius > 0. {
2688                            path.curve_to(bottom_right - curve_width, bottom_right);
2689                        }
2690                        path.line_to(next_top_right + curve_width);
2691                        if self.corner_radius > 0. {
2692                            path.curve_to(next_top_right + curve_height, next_top_right);
2693                        }
2694                    }
2695                    Ordering::Greater => {
2696                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
2697                        path.line_to(bottom_right - curve_height);
2698                        if self.corner_radius > 0. {
2699                            path.curve_to(bottom_right + curve_width, bottom_right);
2700                        }
2701                        path.line_to(next_top_right - curve_width);
2702                        if self.corner_radius > 0. {
2703                            path.curve_to(next_top_right + curve_height, next_top_right);
2704                        }
2705                    }
2706                }
2707            } else {
2708                let curve_width = curve_width(line.start_x, line.end_x);
2709                path.line_to(bottom_right - curve_height);
2710                if self.corner_radius > 0. {
2711                    path.curve_to(bottom_right - curve_width, bottom_right);
2712                }
2713
2714                let bottom_left = vec2f(line.start_x, bottom_right.y());
2715                path.line_to(bottom_left + curve_width);
2716                if self.corner_radius > 0. {
2717                    path.curve_to(bottom_left - curve_height, bottom_left);
2718                }
2719            }
2720        }
2721
2722        if first_line.start_x > last_line.start_x {
2723            let curve_width = curve_width(last_line.start_x, first_line.start_x);
2724            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
2725            path.line_to(second_top_left + curve_height);
2726            if self.corner_radius > 0. {
2727                path.curve_to(second_top_left + curve_width, second_top_left);
2728            }
2729            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
2730            path.line_to(first_bottom_left - curve_width);
2731            if self.corner_radius > 0. {
2732                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
2733            }
2734        }
2735
2736        path.line_to(first_top_left + curve_height);
2737        if self.corner_radius > 0. {
2738            path.curve_to(first_top_left + top_curve_width, first_top_left);
2739        }
2740        path.line_to(first_top_right - top_curve_width);
2741
2742        scene.push_path(path.build(self.color, Some(bounds)));
2743    }
2744}
2745
2746fn position_to_display_point(
2747    position: Vector2F,
2748    text_bounds: RectF,
2749    position_map: &PositionMap,
2750) -> Option<DisplayPoint> {
2751    if text_bounds.contains_point(position) {
2752        let (point, target_point) = position_map.point_for_position(text_bounds, position);
2753        if point == target_point {
2754            Some(point)
2755        } else {
2756            None
2757        }
2758    } else {
2759        None
2760    }
2761}
2762
2763fn range_to_bounds(
2764    range: &Range<DisplayPoint>,
2765    content_origin: Vector2F,
2766    scroll_left: f32,
2767    scroll_top: f32,
2768    visible_row_range: &Range<u32>,
2769    line_end_overshoot: f32,
2770    position_map: &PositionMap,
2771) -> impl Iterator<Item = RectF> {
2772    let mut bounds: SmallVec<[RectF; 1]> = SmallVec::new();
2773
2774    if range.start == range.end {
2775        return bounds.into_iter();
2776    }
2777
2778    let start_row = visible_row_range.start;
2779    let end_row = visible_row_range.end;
2780
2781    let row_range = if range.end.column() == 0 {
2782        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
2783    } else {
2784        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
2785    };
2786
2787    let first_y =
2788        content_origin.y() + row_range.start as f32 * position_map.line_height - scroll_top;
2789
2790    for (idx, row) in row_range.enumerate() {
2791        let line_layout = &position_map.line_layouts[(row - start_row) as usize].line;
2792
2793        let start_x = if row == range.start.row() {
2794            content_origin.x() + line_layout.x_for_index(range.start.column() as usize)
2795                - scroll_left
2796        } else {
2797            content_origin.x() - scroll_left
2798        };
2799
2800        let end_x = if row == range.end.row() {
2801            content_origin.x() + line_layout.x_for_index(range.end.column() as usize) - scroll_left
2802        } else {
2803            content_origin.x() + line_layout.width() + line_end_overshoot - scroll_left
2804        };
2805
2806        bounds.push(RectF::from_points(
2807            vec2f(start_x, first_y + position_map.line_height * idx as f32),
2808            vec2f(end_x, first_y + position_map.line_height * (idx + 1) as f32),
2809        ))
2810    }
2811
2812    bounds.into_iter()
2813}
2814
2815pub fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
2816    delta.powf(1.5) / 100.0
2817}
2818
2819fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
2820    delta.powf(1.2) / 300.0
2821}
2822
2823#[cfg(test)]
2824mod tests {
2825    use super::*;
2826    use crate::{
2827        display_map::{BlockDisposition, BlockProperties},
2828        Editor, MultiBuffer,
2829    };
2830    use gpui::TestAppContext;
2831    use log::info;
2832    use settings::Settings;
2833    use std::{num::NonZeroU32, sync::Arc};
2834    use util::test::sample_text;
2835
2836    #[gpui::test]
2837    fn test_layout_line_numbers(cx: &mut TestAppContext) {
2838        cx.update(|cx| cx.set_global(Settings::test(cx)));
2839        let (_, editor) = cx.add_window(|cx| {
2840            let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
2841            Editor::new(EditorMode::Full, buffer, None, None, cx)
2842        });
2843        let element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
2844
2845        let layouts = editor.update(cx, |editor, cx| {
2846            let snapshot = editor.snapshot(cx);
2847            element
2848                .layout_line_numbers(0..6, &Default::default(), false, &snapshot, cx)
2849                .0
2850        });
2851        assert_eq!(layouts.len(), 6);
2852    }
2853
2854    #[gpui::test]
2855    fn test_layout_with_placeholder_text_and_blocks(cx: &mut TestAppContext) {
2856        cx.update(|cx| cx.set_global(Settings::test(cx)));
2857        let (_, editor) = cx.add_window(|cx| {
2858            let buffer = MultiBuffer::build_simple("", cx);
2859            Editor::new(EditorMode::Full, buffer, None, None, cx)
2860        });
2861
2862        editor.update(cx, |editor, cx| {
2863            editor.set_placeholder_text("hello", cx);
2864            editor.insert_blocks(
2865                [BlockProperties {
2866                    style: BlockStyle::Fixed,
2867                    disposition: BlockDisposition::Above,
2868                    height: 3,
2869                    position: Anchor::min(),
2870                    render: Arc::new(|_| Empty::new().into_any()),
2871                }],
2872                cx,
2873            );
2874
2875            // Blur the editor so that it displays placeholder text.
2876            cx.blur();
2877        });
2878
2879        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
2880        let (size, mut state) = editor.update(cx, |editor, cx| {
2881            let mut new_parents = Default::default();
2882            let mut notify_views_if_parents_change = Default::default();
2883            let mut layout_cx = LayoutContext::new(
2884                cx,
2885                &mut new_parents,
2886                &mut notify_views_if_parents_change,
2887                false,
2888            );
2889            element.layout(
2890                SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
2891                editor,
2892                &mut layout_cx,
2893            )
2894        });
2895
2896        assert_eq!(state.position_map.line_layouts.len(), 4);
2897        assert_eq!(
2898            state
2899                .line_number_layouts
2900                .iter()
2901                .map(Option::is_some)
2902                .collect::<Vec<_>>(),
2903            &[false, false, false, true]
2904        );
2905
2906        // Don't panic.
2907        let mut scene = SceneBuilder::new(1.0);
2908        let bounds = RectF::new(Default::default(), size);
2909        editor.update(cx, |editor, cx| {
2910            element.paint(&mut scene, bounds, bounds, &mut state, editor, cx);
2911        });
2912    }
2913
2914    #[gpui::test]
2915    fn test_all_invisibles_drawing(cx: &mut TestAppContext) {
2916        let tab_size = 4;
2917        let input_text = "\t \t|\t| a b";
2918        let expected_invisibles = vec![
2919            Invisible::Tab {
2920                line_start_offset: 0,
2921            },
2922            Invisible::Whitespace {
2923                line_offset: tab_size as usize,
2924            },
2925            Invisible::Tab {
2926                line_start_offset: tab_size as usize + 1,
2927            },
2928            Invisible::Tab {
2929                line_start_offset: tab_size as usize * 2 + 1,
2930            },
2931            Invisible::Whitespace {
2932                line_offset: tab_size as usize * 3 + 1,
2933            },
2934            Invisible::Whitespace {
2935                line_offset: tab_size as usize * 3 + 3,
2936            },
2937        ];
2938        assert_eq!(
2939            expected_invisibles.len(),
2940            input_text
2941                .chars()
2942                .filter(|initial_char| initial_char.is_whitespace())
2943                .count(),
2944            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
2945        );
2946
2947        cx.update(|cx| {
2948            let mut test_settings = Settings::test(cx);
2949            test_settings.editor_defaults.show_whitespaces = Some(ShowWhitespaces::All);
2950            test_settings.editor_defaults.tab_size = Some(NonZeroU32::new(tab_size).unwrap());
2951            cx.set_global(test_settings);
2952        });
2953        let actual_invisibles =
2954            collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, 500.0);
2955
2956        assert_eq!(expected_invisibles, actual_invisibles);
2957    }
2958
2959    #[gpui::test]
2960    fn test_invisibles_dont_appear_in_certain_editors(cx: &mut TestAppContext) {
2961        cx.update(|cx| {
2962            let mut test_settings = Settings::test(cx);
2963            test_settings.editor_defaults.show_whitespaces = Some(ShowWhitespaces::All);
2964            test_settings.editor_defaults.tab_size = Some(NonZeroU32::new(4).unwrap());
2965            cx.set_global(test_settings);
2966        });
2967
2968        for editor_mode_without_invisibles in [
2969            EditorMode::SingleLine,
2970            EditorMode::AutoHeight { max_lines: 100 },
2971        ] {
2972            let invisibles = collect_invisibles_from_new_editor(
2973                cx,
2974                editor_mode_without_invisibles,
2975                "\t\t\t| | a b",
2976                500.0,
2977            );
2978            assert!(invisibles.is_empty(),
2979                "For editor mode {editor_mode_without_invisibles:?} no invisibles was expected but got {invisibles:?}");
2980        }
2981    }
2982
2983    #[gpui::test]
2984    fn test_wrapped_invisibles_drawing(cx: &mut TestAppContext) {
2985        let tab_size = 4;
2986        let input_text = "a\tbcd   ".repeat(9);
2987        let repeated_invisibles = [
2988            Invisible::Tab {
2989                line_start_offset: 1,
2990            },
2991            Invisible::Whitespace {
2992                line_offset: tab_size as usize + 3,
2993            },
2994            Invisible::Whitespace {
2995                line_offset: tab_size as usize + 4,
2996            },
2997            Invisible::Whitespace {
2998                line_offset: tab_size as usize + 5,
2999            },
3000        ];
3001        let expected_invisibles = std::iter::once(repeated_invisibles)
3002            .cycle()
3003            .take(9)
3004            .flatten()
3005            .collect::<Vec<_>>();
3006        assert_eq!(
3007            expected_invisibles.len(),
3008            input_text
3009                .chars()
3010                .filter(|initial_char| initial_char.is_whitespace())
3011                .count(),
3012            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
3013        );
3014        info!("Expected invisibles: {expected_invisibles:?}");
3015
3016        // Put the same string with repeating whitespace pattern into editors of various size,
3017        // take deliberately small steps during resizing, to put all whitespace kinds near the wrap point.
3018        let resize_step = 10.0;
3019        let mut editor_width = 200.0;
3020        while editor_width <= 1000.0 {
3021            cx.update(|cx| {
3022                let mut test_settings = Settings::test(cx);
3023                test_settings.editor_defaults.tab_size = Some(NonZeroU32::new(tab_size).unwrap());
3024                test_settings.editor_defaults.show_whitespaces = Some(ShowWhitespaces::All);
3025                test_settings.editor_defaults.preferred_line_length = Some(editor_width as u32);
3026                test_settings.editor_defaults.soft_wrap =
3027                    Some(settings::SoftWrap::PreferredLineLength);
3028                cx.set_global(test_settings);
3029            });
3030
3031            let actual_invisibles =
3032                collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, editor_width);
3033
3034            // Whatever the editor size is, ensure it has the same invisible kinds in the same order
3035            // (no good guarantees about the offsets: wrapping could trigger padding and its tests should check the offsets).
3036            let mut i = 0;
3037            for (actual_index, actual_invisible) in actual_invisibles.iter().enumerate() {
3038                i = actual_index;
3039                match expected_invisibles.get(i) {
3040                    Some(expected_invisible) => match (expected_invisible, actual_invisible) {
3041                        (Invisible::Whitespace { .. }, Invisible::Whitespace { .. })
3042                        | (Invisible::Tab { .. }, Invisible::Tab { .. }) => {}
3043                        _ => {
3044                            panic!("At index {i}, expected invisible {expected_invisible:?} does not match actual {actual_invisible:?} by kind. Actual invisibles: {actual_invisibles:?}")
3045                        }
3046                    },
3047                    None => panic!("Unexpected extra invisible {actual_invisible:?} at index {i}"),
3048                }
3049            }
3050            let missing_expected_invisibles = &expected_invisibles[i + 1..];
3051            assert!(
3052                missing_expected_invisibles.is_empty(),
3053                "Missing expected invisibles after index {i}: {missing_expected_invisibles:?}"
3054            );
3055
3056            editor_width += resize_step;
3057        }
3058    }
3059
3060    fn collect_invisibles_from_new_editor(
3061        cx: &mut TestAppContext,
3062        editor_mode: EditorMode,
3063        input_text: &str,
3064        editor_width: f32,
3065    ) -> Vec<Invisible> {
3066        info!(
3067            "Creating editor with mode {editor_mode:?}, witdh {editor_width} and text '{input_text}'"
3068        );
3069        let (_, editor) = cx.add_window(|cx| {
3070            let buffer = MultiBuffer::build_simple(&input_text, cx);
3071            Editor::new(editor_mode, buffer, None, None, cx)
3072        });
3073
3074        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3075        let (_, layout_state) = editor.update(cx, |editor, cx| {
3076            editor.set_soft_wrap_mode(settings::SoftWrap::EditorWidth, cx);
3077            editor.set_wrap_width(Some(editor_width), cx);
3078
3079            let mut new_parents = Default::default();
3080            let mut notify_views_if_parents_change = Default::default();
3081            let mut layout_cx = LayoutContext::new(
3082                cx,
3083                &mut new_parents,
3084                &mut notify_views_if_parents_change,
3085                false,
3086            );
3087            element.layout(
3088                SizeConstraint::new(vec2f(editor_width, 500.), vec2f(editor_width, 500.)),
3089                editor,
3090                &mut layout_cx,
3091            )
3092        });
3093
3094        layout_state
3095            .position_map
3096            .line_layouts
3097            .iter()
3098            .map(|line_with_invisibles| &line_with_invisibles.invisibles)
3099            .flatten()
3100            .cloned()
3101            .collect()
3102    }
3103}