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    editor_settings::ShowScrollbar,
   9    git::{diff_hunk_to_display, DisplayDiffHunk},
  10    hover_popover::{
  11        hide_hover, hover_at, HOVER_POPOVER_GAP, MIN_POPOVER_CHARACTER_WIDTH,
  12        MIN_POPOVER_LINE_HEIGHT,
  13    },
  14    link_go_to_definition::{
  15        go_to_fetched_definition, go_to_fetched_type_definition, update_go_to_definition_link,
  16    },
  17    mouse_context_menu, EditorSettings, EditorStyle, GutterHover, UnfoldAt,
  18};
  19use clock::ReplicaId;
  20use collections::{BTreeMap, HashMap};
  21use git::diff::DiffHunkStatus;
  22use gpui::{
  23    color::Color,
  24    elements::*,
  25    fonts::{HighlightStyle, TextStyle, Underline},
  26    geometry::{
  27        rect::RectF,
  28        vector::{vec2f, Vector2F},
  29        PathBuilder,
  30    },
  31    json::{self, ToJson},
  32    platform::{CursorStyle, Modifiers, MouseButton, MouseButtonEvent, MouseMovedEvent},
  33    text_layout::{self, Line, RunStyle, TextLayoutCache},
  34    AnyElement, Axis, Border, CursorRegion, Element, EventContext, FontCache, LayoutContext,
  35    MouseRegion, PaintContext, Quad, SceneBuilder, SizeConstraint, ViewContext, WindowContext,
  36};
  37use itertools::Itertools;
  38use json::json;
  39use language::{
  40    language_settings::ShowWhitespaceSetting, Bias, CursorShape, DiagnosticSeverity, OffsetUtf16,
  41    Selection,
  42};
  43use project::{
  44    project_settings::{GitGutterSetting, ProjectSettings},
  45    ProjectPath,
  46};
  47use smallvec::SmallVec;
  48use std::{
  49    borrow::Cow,
  50    cmp::{self, Ordering},
  51    fmt::Write,
  52    iter,
  53    ops::Range,
  54    sync::Arc,
  55};
  56use text::Point;
  57use workspace::item::Item;
  58
  59enum FoldMarkers {}
  60
  61struct SelectionLayout {
  62    head: DisplayPoint,
  63    cursor_shape: CursorShape,
  64    is_newest: bool,
  65    range: Range<DisplayPoint>,
  66    active_rows: Range<u32>,
  67}
  68
  69impl SelectionLayout {
  70    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  71        selection: Selection<T>,
  72        line_mode: bool,
  73        cursor_shape: CursorShape,
  74        map: &DisplaySnapshot,
  75        is_newest: bool,
  76    ) -> Self {
  77        let point_selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  78        let display_selection = point_selection.map(|p| p.to_display_point(map));
  79        let mut range = display_selection.range();
  80        let mut head = display_selection.head();
  81        let mut active_rows = map.prev_line_boundary(point_selection.start).1.row()
  82            ..map.next_line_boundary(point_selection.end).1.row();
  83
  84        // vim visual line mode
  85        if line_mode {
  86            let point_range = map.expand_to_line(point_selection.range());
  87            range = point_range.start.to_display_point(map)..point_range.end.to_display_point(map);
  88        }
  89
  90        // any vim visual mode (including line mode)
  91        if cursor_shape == CursorShape::Block && !range.is_empty() && !selection.reversed {
  92            if head.column() > 0 {
  93                head = map.clip_point(DisplayPoint::new(head.row(), head.column() - 1), Bias::Left)
  94            } else if head.row() > 0 && head != map.max_point() {
  95                head = map.clip_point(
  96                    DisplayPoint::new(head.row() - 1, map.line_len(head.row() - 1)),
  97                    Bias::Left,
  98                );
  99                // updating range.end is a no-op unless you're cursor is
 100                // on the newline containing a multi-buffer divider
 101                // in which case the clip_point may have moved the head up
 102                // an additional row.
 103                range.end = DisplayPoint::new(head.row() + 1, 0);
 104                active_rows.end = head.row();
 105            }
 106        }
 107
 108        Self {
 109            head,
 110            cursor_shape,
 111            is_newest,
 112            range,
 113            active_rows,
 114        }
 115    }
 116}
 117
 118pub struct EditorElement {
 119    style: Arc<EditorStyle>,
 120}
 121
 122impl EditorElement {
 123    pub fn new(style: EditorStyle) -> Self {
 124        Self {
 125            style: Arc::new(style),
 126        }
 127    }
 128
 129    fn attach_mouse_handlers(
 130        scene: &mut SceneBuilder,
 131        position_map: &Arc<PositionMap>,
 132        has_popovers: bool,
 133        visible_bounds: RectF,
 134        text_bounds: RectF,
 135        gutter_bounds: RectF,
 136        bounds: RectF,
 137        cx: &mut ViewContext<Editor>,
 138    ) {
 139        enum EditorElementMouseHandlers {}
 140        scene.push_mouse_region(
 141            MouseRegion::new::<EditorElementMouseHandlers>(
 142                cx.view_id(),
 143                cx.view_id(),
 144                visible_bounds,
 145            )
 146            .on_down(MouseButton::Left, {
 147                let position_map = position_map.clone();
 148                move |event, editor, cx| {
 149                    if !Self::mouse_down(
 150                        editor,
 151                        event.platform_event,
 152                        position_map.as_ref(),
 153                        text_bounds,
 154                        gutter_bounds,
 155                        cx,
 156                    ) {
 157                        cx.propagate_event();
 158                    }
 159                }
 160            })
 161            .on_down(MouseButton::Right, {
 162                let position_map = position_map.clone();
 163                move |event, editor, cx| {
 164                    if !Self::mouse_right_down(
 165                        editor,
 166                        event.position,
 167                        position_map.as_ref(),
 168                        text_bounds,
 169                        cx,
 170                    ) {
 171                        cx.propagate_event();
 172                    }
 173                }
 174            })
 175            .on_up(MouseButton::Left, {
 176                let position_map = position_map.clone();
 177                move |event, editor, cx| {
 178                    if !Self::mouse_up(
 179                        editor,
 180                        event.position,
 181                        event.cmd,
 182                        event.shift,
 183                        event.alt,
 184                        position_map.as_ref(),
 185                        text_bounds,
 186                        cx,
 187                    ) {
 188                        cx.propagate_event()
 189                    }
 190                }
 191            })
 192            .on_drag(MouseButton::Left, {
 193                let position_map = position_map.clone();
 194                move |event, editor, cx| {
 195                    if event.end {
 196                        return;
 197                    }
 198
 199                    if !Self::mouse_dragged(
 200                        editor,
 201                        event.platform_event,
 202                        position_map.as_ref(),
 203                        text_bounds,
 204                        cx,
 205                    ) {
 206                        cx.propagate_event()
 207                    }
 208                }
 209            })
 210            .on_move({
 211                let position_map = position_map.clone();
 212                move |event, editor, cx| {
 213                    if !Self::mouse_moved(
 214                        editor,
 215                        event.platform_event,
 216                        &position_map,
 217                        text_bounds,
 218                        cx,
 219                    ) {
 220                        cx.propagate_event()
 221                    }
 222                }
 223            })
 224            .on_move_out(move |_, editor: &mut Editor, cx| {
 225                if has_popovers {
 226                    hide_hover(editor, cx);
 227                }
 228            })
 229            .on_scroll({
 230                let position_map = position_map.clone();
 231                move |event, editor, cx| {
 232                    if !Self::scroll(
 233                        editor,
 234                        event.position,
 235                        *event.delta.raw(),
 236                        event.delta.precise(),
 237                        &position_map,
 238                        bounds,
 239                        cx,
 240                    ) {
 241                        cx.propagate_event()
 242                    }
 243                }
 244            }),
 245        );
 246
 247        enum GutterHandlers {}
 248        scene.push_mouse_region(
 249            MouseRegion::new::<GutterHandlers>(cx.view_id(), cx.view_id() + 1, gutter_bounds)
 250                .on_hover(|hover, editor: &mut Editor, cx| {
 251                    editor.gutter_hover(
 252                        &GutterHover {
 253                            hovered: hover.started,
 254                        },
 255                        cx,
 256                    );
 257                }),
 258        )
 259    }
 260
 261    fn mouse_down(
 262        editor: &mut Editor,
 263        MouseButtonEvent {
 264            position,
 265            modifiers:
 266                Modifiers {
 267                    shift,
 268                    ctrl,
 269                    alt,
 270                    cmd,
 271                    ..
 272                },
 273            mut click_count,
 274            ..
 275        }: MouseButtonEvent,
 276        position_map: &PositionMap,
 277        text_bounds: RectF,
 278        gutter_bounds: RectF,
 279        cx: &mut EventContext<Editor>,
 280    ) -> bool {
 281        if gutter_bounds.contains_point(position) {
 282            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 283        } else if !text_bounds.contains_point(position) {
 284            return false;
 285        }
 286
 287        let (position, target_position) = position_map.point_for_position(text_bounds, position);
 288
 289        if shift && alt {
 290            editor.select(
 291                SelectPhase::BeginColumnar {
 292                    position,
 293                    goal_column: target_position.column(),
 294                },
 295                cx,
 296            );
 297        } else if shift && !ctrl && !alt && !cmd {
 298            editor.select(
 299                SelectPhase::Extend {
 300                    position,
 301                    click_count,
 302                },
 303                cx,
 304            );
 305        } else {
 306            editor.select(
 307                SelectPhase::Begin {
 308                    position,
 309                    add: alt,
 310                    click_count,
 311                },
 312                cx,
 313            );
 314        }
 315
 316        true
 317    }
 318
 319    fn mouse_right_down(
 320        editor: &mut Editor,
 321        position: Vector2F,
 322        position_map: &PositionMap,
 323        text_bounds: RectF,
 324        cx: &mut EventContext<Editor>,
 325    ) -> bool {
 326        if !text_bounds.contains_point(position) {
 327            return false;
 328        }
 329
 330        let (point, _) = position_map.point_for_position(text_bounds, position);
 331        mouse_context_menu::deploy_context_menu(editor, position, point, cx);
 332        true
 333    }
 334
 335    fn mouse_up(
 336        editor: &mut Editor,
 337        position: Vector2F,
 338        cmd: bool,
 339        shift: bool,
 340        alt: bool,
 341        position_map: &PositionMap,
 342        text_bounds: RectF,
 343        cx: &mut EventContext<Editor>,
 344    ) -> bool {
 345        let end_selection = editor.has_pending_selection();
 346        let pending_nonempty_selections = editor.has_pending_nonempty_selection();
 347
 348        if end_selection {
 349            editor.select(SelectPhase::End, cx);
 350        }
 351
 352        if !pending_nonempty_selections && cmd && text_bounds.contains_point(position) {
 353            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 354
 355            if point == target_point {
 356                if shift {
 357                    go_to_fetched_type_definition(editor, point, alt, cx);
 358                } else {
 359                    go_to_fetched_definition(editor, point, alt, cx);
 360                }
 361
 362                return true;
 363            }
 364        }
 365
 366        end_selection
 367    }
 368
 369    fn mouse_dragged(
 370        editor: &mut Editor,
 371        MouseMovedEvent {
 372            modifiers: Modifiers { cmd, shift, .. },
 373            position,
 374            ..
 375        }: MouseMovedEvent,
 376        position_map: &PositionMap,
 377        text_bounds: RectF,
 378        cx: &mut EventContext<Editor>,
 379    ) -> bool {
 380        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 381        // Don't trigger hover popover if mouse is hovering over context menu
 382        let point = if text_bounds.contains_point(position) {
 383            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 384            if point == target_point {
 385                Some(point)
 386            } else {
 387                None
 388            }
 389        } else {
 390            None
 391        };
 392
 393        update_go_to_definition_link(editor, point, cmd, shift, cx);
 394
 395        if editor.has_pending_selection() {
 396            let mut scroll_delta = Vector2F::zero();
 397
 398            let vertical_margin = position_map.line_height.min(text_bounds.height() / 3.0);
 399            let top = text_bounds.origin_y() + vertical_margin;
 400            let bottom = text_bounds.lower_left().y() - vertical_margin;
 401            if position.y() < top {
 402                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 403            }
 404            if position.y() > bottom {
 405                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 406            }
 407
 408            let horizontal_margin = position_map.line_height.min(text_bounds.width() / 3.0);
 409            let left = text_bounds.origin_x() + horizontal_margin;
 410            let right = text_bounds.upper_right().x() - horizontal_margin;
 411            if position.x() < left {
 412                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 413                    left - position.x(),
 414                ))
 415            }
 416            if position.x() > right {
 417                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 418                    position.x() - right,
 419                ))
 420            }
 421
 422            let (position, target_position) =
 423                position_map.point_for_position(text_bounds, position);
 424
 425            editor.select(
 426                SelectPhase::Update {
 427                    position,
 428                    goal_column: target_position.column(),
 429                    scroll_position: (position_map.snapshot.scroll_position() + scroll_delta)
 430                        .clamp(Vector2F::zero(), position_map.scroll_max),
 431                },
 432                cx,
 433            );
 434            hover_at(editor, point, cx);
 435            true
 436        } else {
 437            hover_at(editor, point, cx);
 438            false
 439        }
 440    }
 441
 442    fn mouse_moved(
 443        editor: &mut Editor,
 444        MouseMovedEvent {
 445            modifiers: Modifiers { shift, cmd, .. },
 446            position,
 447            ..
 448        }: MouseMovedEvent,
 449        position_map: &PositionMap,
 450        text_bounds: RectF,
 451        cx: &mut ViewContext<Editor>,
 452    ) -> bool {
 453        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 454        // Don't trigger hover popover if mouse is hovering over context menu
 455        let point = position_to_display_point(position, text_bounds, position_map);
 456
 457        update_go_to_definition_link(editor, point, cmd, shift, cx);
 458        hover_at(editor, point, cx);
 459
 460        true
 461    }
 462
 463    fn scroll(
 464        editor: &mut Editor,
 465        position: Vector2F,
 466        mut delta: Vector2F,
 467        precise: bool,
 468        position_map: &PositionMap,
 469        bounds: RectF,
 470        cx: &mut ViewContext<Editor>,
 471    ) -> bool {
 472        if !bounds.contains_point(position) {
 473            return false;
 474        }
 475
 476        let line_height = position_map.line_height;
 477        let max_glyph_width = position_map.em_width;
 478
 479        let axis = if precise {
 480            //Trackpad
 481            position_map.snapshot.ongoing_scroll.filter(&mut delta)
 482        } else {
 483            //Not trackpad
 484            delta *= vec2f(max_glyph_width, line_height);
 485            None //Resets ongoing scroll
 486        };
 487
 488        let scroll_position = position_map.snapshot.scroll_position();
 489        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 490        let y = (scroll_position.y() * line_height - delta.y()) / line_height;
 491        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), position_map.scroll_max);
 492        editor.scroll(scroll_position, axis, cx);
 493
 494        true
 495    }
 496
 497    fn paint_background(
 498        &self,
 499        scene: &mut SceneBuilder,
 500        gutter_bounds: RectF,
 501        text_bounds: RectF,
 502        layout: &LayoutState,
 503    ) {
 504        let bounds = gutter_bounds.union_rect(text_bounds);
 505        let scroll_top =
 506            layout.position_map.snapshot.scroll_position().y() * layout.position_map.line_height;
 507        scene.push_quad(Quad {
 508            bounds: gutter_bounds,
 509            background: Some(self.style.gutter_background),
 510            border: Border::new(0., Color::transparent_black()),
 511            corner_radii: Default::default(),
 512        });
 513        scene.push_quad(Quad {
 514            bounds: text_bounds,
 515            background: Some(self.style.background),
 516            border: Border::new(0., Color::transparent_black()),
 517            corner_radii: Default::default(),
 518        });
 519
 520        if let EditorMode::Full = layout.mode {
 521            let mut active_rows = layout.active_rows.iter().peekable();
 522            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 523                let mut end_row = *start_row;
 524                while active_rows.peek().map_or(false, |r| {
 525                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 526                }) {
 527                    active_rows.next().unwrap();
 528                    end_row += 1;
 529                }
 530
 531                if !contains_non_empty_selection {
 532                    let origin = vec2f(
 533                        bounds.origin_x(),
 534                        bounds.origin_y() + (layout.position_map.line_height * *start_row as f32)
 535                            - scroll_top,
 536                    );
 537                    let size = vec2f(
 538                        bounds.width(),
 539                        layout.position_map.line_height * (end_row - start_row + 1) as f32,
 540                    );
 541                    scene.push_quad(Quad {
 542                        bounds: RectF::new(origin, size),
 543                        background: Some(self.style.active_line_background),
 544                        border: Border::default(),
 545                        corner_radii: Default::default(),
 546                    });
 547                }
 548            }
 549
 550            if let Some(highlighted_rows) = &layout.highlighted_rows {
 551                let origin = vec2f(
 552                    bounds.origin_x(),
 553                    bounds.origin_y()
 554                        + (layout.position_map.line_height * highlighted_rows.start as f32)
 555                        - scroll_top,
 556                );
 557                let size = vec2f(
 558                    bounds.width(),
 559                    layout.position_map.line_height * highlighted_rows.len() as f32,
 560                );
 561                scene.push_quad(Quad {
 562                    bounds: RectF::new(origin, size),
 563                    background: Some(self.style.highlighted_line_background),
 564                    border: Border::default(),
 565                    corner_radii: Default::default(),
 566                });
 567            }
 568
 569            let scroll_left =
 570                layout.position_map.snapshot.scroll_position().x() * layout.position_map.em_width;
 571
 572            for (wrap_position, active) in layout.wrap_guides.iter() {
 573                let x =
 574                    (text_bounds.origin_x() + wrap_position + layout.position_map.em_width / 2.)
 575                        - scroll_left;
 576
 577                if x < text_bounds.origin_x()
 578                    || (layout.show_scrollbars && x > self.scrollbar_left(&bounds))
 579                {
 580                    continue;
 581                }
 582
 583                let color = if *active {
 584                    self.style.active_wrap_guide
 585                } else {
 586                    self.style.wrap_guide
 587                };
 588                scene.push_quad(Quad {
 589                    bounds: RectF::new(
 590                        vec2f(x, text_bounds.origin_y()),
 591                        vec2f(1., text_bounds.height()),
 592                    ),
 593                    background: Some(color),
 594                    border: Border::new(0., Color::transparent_black()),
 595                    corner_radii: Default::default(),
 596                });
 597            }
 598        }
 599    }
 600
 601    fn paint_gutter(
 602        &mut self,
 603        scene: &mut SceneBuilder,
 604        bounds: RectF,
 605        visible_bounds: RectF,
 606        layout: &mut LayoutState,
 607        editor: &mut Editor,
 608        cx: &mut PaintContext<Editor>,
 609    ) {
 610        let line_height = layout.position_map.line_height;
 611
 612        let scroll_position = layout.position_map.snapshot.scroll_position();
 613        let scroll_top = scroll_position.y() * line_height;
 614
 615        let show_gutter = matches!(
 616            settings::get::<ProjectSettings>(cx).git.git_gutter,
 617            Some(GitGutterSetting::TrackedFiles)
 618        );
 619
 620        if show_gutter {
 621            Self::paint_diff_hunks(scene, bounds, layout, cx);
 622        }
 623
 624        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 625            if let Some(line) = line {
 626                let line_origin = bounds.origin()
 627                    + vec2f(
 628                        bounds.width() - line.width() - layout.gutter_padding,
 629                        ix as f32 * line_height - (scroll_top % line_height),
 630                    );
 631
 632                line.paint(scene, line_origin, visible_bounds, line_height, cx);
 633            }
 634        }
 635
 636        for (ix, fold_indicator) in layout.fold_indicators.iter_mut().enumerate() {
 637            if let Some(indicator) = fold_indicator.as_mut() {
 638                let position = vec2f(
 639                    bounds.width() - layout.gutter_padding,
 640                    ix as f32 * line_height - (scroll_top % line_height),
 641                );
 642                let centering_offset = vec2f(
 643                    (layout.gutter_padding + layout.gutter_margin - indicator.size().x()) / 2.,
 644                    (line_height - indicator.size().y()) / 2.,
 645                );
 646
 647                let indicator_origin = bounds.origin() + position + centering_offset;
 648
 649                indicator.paint(scene, indicator_origin, visible_bounds, editor, cx);
 650            }
 651        }
 652
 653        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 654            let mut x = 0.;
 655            let mut y = *row as f32 * line_height - scroll_top;
 656            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 657            y += (line_height - indicator.size().y()) / 2.;
 658            indicator.paint(
 659                scene,
 660                bounds.origin() + vec2f(x, y),
 661                visible_bounds,
 662                editor,
 663                cx,
 664            );
 665        }
 666    }
 667
 668    fn paint_diff_hunks(
 669        scene: &mut SceneBuilder,
 670        bounds: RectF,
 671        layout: &mut LayoutState,
 672        cx: &mut ViewContext<Editor>,
 673    ) {
 674        let diff_style = &theme::current(cx).editor.diff.clone();
 675        let line_height = layout.position_map.line_height;
 676
 677        let scroll_position = layout.position_map.snapshot.scroll_position();
 678        let scroll_top = scroll_position.y() * line_height;
 679
 680        for hunk in &layout.display_hunks {
 681            let (display_row_range, status) = match hunk {
 682                //TODO: This rendering is entirely a horrible hack
 683                &DisplayDiffHunk::Folded { display_row: row } => {
 684                    let start_y = row as f32 * line_height - scroll_top;
 685                    let end_y = start_y + line_height;
 686
 687                    let width = diff_style.removed_width_em * line_height;
 688                    let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 689                    let highlight_size = vec2f(width * 2., end_y - start_y);
 690                    let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 691
 692                    scene.push_quad(Quad {
 693                        bounds: highlight_bounds,
 694                        background: Some(diff_style.modified),
 695                        border: Border::new(0., Color::transparent_black()),
 696                        corner_radii: (1. * line_height).into(),
 697                    });
 698
 699                    continue;
 700                }
 701
 702                DisplayDiffHunk::Unfolded {
 703                    display_row_range,
 704                    status,
 705                } => (display_row_range, status),
 706            };
 707
 708            let color = match status {
 709                DiffHunkStatus::Added => diff_style.inserted,
 710                DiffHunkStatus::Modified => diff_style.modified,
 711
 712                //TODO: This rendering is entirely a horrible hack
 713                DiffHunkStatus::Removed => {
 714                    let row = display_row_range.start;
 715
 716                    let offset = line_height / 2.;
 717                    let start_y = row as f32 * line_height - offset - scroll_top;
 718                    let end_y = start_y + line_height;
 719
 720                    let width = diff_style.removed_width_em * line_height;
 721                    let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 722                    let highlight_size = vec2f(width * 2., end_y - start_y);
 723                    let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 724
 725                    scene.push_quad(Quad {
 726                        bounds: highlight_bounds,
 727                        background: Some(diff_style.deleted),
 728                        border: Border::new(0., Color::transparent_black()),
 729                        corner_radii: (1. * line_height).into(),
 730                    });
 731
 732                    continue;
 733                }
 734            };
 735
 736            let start_row = display_row_range.start;
 737            let end_row = display_row_range.end;
 738
 739            let start_y = start_row as f32 * line_height - scroll_top;
 740            let end_y = end_row as f32 * line_height - scroll_top;
 741
 742            let width = diff_style.width_em * line_height;
 743            let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 744            let highlight_size = vec2f(width * 2., end_y - start_y);
 745            let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 746
 747            scene.push_quad(Quad {
 748                bounds: highlight_bounds,
 749                background: Some(color),
 750                border: Border::new(0., Color::transparent_black()),
 751                corner_radii: (diff_style.corner_radius * line_height).into(),
 752            });
 753        }
 754    }
 755
 756    fn paint_text(
 757        &mut self,
 758        scene: &mut SceneBuilder,
 759        bounds: RectF,
 760        visible_bounds: RectF,
 761        layout: &mut LayoutState,
 762        editor: &mut Editor,
 763        cx: &mut PaintContext<Editor>,
 764    ) {
 765        let style = &self.style;
 766        let local_replica_id = editor.replica_id(cx);
 767        let scroll_position = layout.position_map.snapshot.scroll_position();
 768        let start_row = layout.visible_display_row_range.start;
 769        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 770        let max_glyph_width = layout.position_map.em_width;
 771        let scroll_left = scroll_position.x() * max_glyph_width;
 772        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 773        let line_end_overshoot = 0.15 * layout.position_map.line_height;
 774        let whitespace_setting = editor.buffer.read(cx).settings_at(0, cx).show_whitespaces;
 775
 776        scene.push_layer(Some(bounds));
 777
 778        scene.push_cursor_region(CursorRegion {
 779            bounds,
 780            style: if !editor.link_go_to_definition_state.definitions.is_empty() {
 781                CursorStyle::PointingHand
 782            } else {
 783                CursorStyle::IBeam
 784            },
 785        });
 786
 787        let fold_corner_radius =
 788            self.style.folds.ellipses.corner_radius_factor * layout.position_map.line_height;
 789        for (id, range, color) in layout.fold_ranges.iter() {
 790            self.paint_highlighted_range(
 791                scene,
 792                range.clone(),
 793                *color,
 794                fold_corner_radius,
 795                fold_corner_radius * 2.,
 796                layout,
 797                content_origin,
 798                scroll_top,
 799                scroll_left,
 800                bounds,
 801            );
 802
 803            for bound in range_to_bounds(
 804                &range,
 805                content_origin,
 806                scroll_left,
 807                scroll_top,
 808                &layout.visible_display_row_range,
 809                line_end_overshoot,
 810                &layout.position_map,
 811            ) {
 812                scene.push_cursor_region(CursorRegion {
 813                    bounds: bound,
 814                    style: CursorStyle::PointingHand,
 815                });
 816
 817                let display_row = range.start.row();
 818
 819                let buffer_row = DisplayPoint::new(display_row, 0)
 820                    .to_point(&layout.position_map.snapshot.display_snapshot)
 821                    .row;
 822
 823                scene.push_mouse_region(
 824                    MouseRegion::new::<FoldMarkers>(cx.view_id(), *id as usize, bound)
 825                        .on_click(MouseButton::Left, move |_, editor: &mut Editor, cx| {
 826                            editor.unfold_at(&UnfoldAt { buffer_row }, cx)
 827                        })
 828                        .with_notify_on_hover(true)
 829                        .with_notify_on_click(true),
 830                )
 831            }
 832        }
 833
 834        for (range, color) in &layout.highlighted_ranges {
 835            self.paint_highlighted_range(
 836                scene,
 837                range.clone(),
 838                *color,
 839                0.,
 840                line_end_overshoot,
 841                layout,
 842                content_origin,
 843                scroll_top,
 844                scroll_left,
 845                bounds,
 846            );
 847        }
 848
 849        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 850        let corner_radius = 0.15 * layout.position_map.line_height;
 851        let mut invisible_display_ranges = SmallVec::<[Range<DisplayPoint>; 32]>::new();
 852
 853        for (replica_id, selections) in &layout.selections {
 854            let replica_id = *replica_id;
 855            let selection_style = style.replica_selection_style(replica_id);
 856
 857            for selection in selections {
 858                if !selection.range.is_empty()
 859                    && (replica_id == local_replica_id
 860                        || Some(replica_id) == editor.leader_replica_id)
 861                {
 862                    invisible_display_ranges.push(selection.range.clone());
 863                }
 864                self.paint_highlighted_range(
 865                    scene,
 866                    selection.range.clone(),
 867                    selection_style.selection,
 868                    corner_radius,
 869                    corner_radius * 2.,
 870                    layout,
 871                    content_origin,
 872                    scroll_top,
 873                    scroll_left,
 874                    bounds,
 875                );
 876
 877                if editor.show_local_cursors(cx) || replica_id != local_replica_id {
 878                    let cursor_position = selection.head;
 879                    if layout
 880                        .visible_display_row_range
 881                        .contains(&cursor_position.row())
 882                    {
 883                        let cursor_row_layout = &layout.position_map.line_layouts
 884                            [(cursor_position.row() - start_row) as usize]
 885                            .line;
 886                        let cursor_column = cursor_position.column() as usize;
 887
 888                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 889                        let mut block_width =
 890                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 891                        if block_width == 0.0 {
 892                            block_width = layout.position_map.em_width;
 893                        }
 894                        let block_text = if let CursorShape::Block = selection.cursor_shape {
 895                            layout
 896                                .position_map
 897                                .snapshot
 898                                .chars_at(cursor_position)
 899                                .next()
 900                                .and_then(|(character, _)| {
 901                                    let font_id =
 902                                        cursor_row_layout.font_for_index(cursor_column)?;
 903                                    let text = character.to_string();
 904
 905                                    Some(cx.text_layout_cache().layout_str(
 906                                        &text,
 907                                        cursor_row_layout.font_size(),
 908                                        &[(
 909                                            text.len(),
 910                                            RunStyle {
 911                                                font_id,
 912                                                color: style.background,
 913                                                underline: Default::default(),
 914                                            },
 915                                        )],
 916                                    ))
 917                                })
 918                        } else {
 919                            None
 920                        };
 921
 922                        let x = cursor_character_x - scroll_left;
 923                        let y = cursor_position.row() as f32 * layout.position_map.line_height
 924                            - scroll_top;
 925                        if selection.is_newest {
 926                            editor.pixel_position_of_newest_cursor = Some(vec2f(
 927                                bounds.origin_x() + x + block_width / 2.,
 928                                bounds.origin_y() + y + layout.position_map.line_height / 2.,
 929                            ));
 930                        }
 931                        cursors.push(Cursor {
 932                            color: selection_style.cursor,
 933                            block_width,
 934                            origin: vec2f(x, y),
 935                            line_height: layout.position_map.line_height,
 936                            shape: selection.cursor_shape,
 937                            block_text,
 938                        });
 939                    }
 940                }
 941            }
 942        }
 943
 944        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 945            for (ix, line_with_invisibles) in layout.position_map.line_layouts.iter().enumerate() {
 946                let row = start_row + ix as u32;
 947                line_with_invisibles.draw(
 948                    layout,
 949                    row,
 950                    scroll_top,
 951                    scene,
 952                    content_origin,
 953                    scroll_left,
 954                    visible_text_bounds,
 955                    whitespace_setting,
 956                    &invisible_display_ranges,
 957                    visible_bounds,
 958                    cx,
 959                )
 960            }
 961        }
 962
 963        scene.paint_layer(Some(bounds), |scene| {
 964            for cursor in cursors {
 965                cursor.paint(scene, content_origin, cx);
 966            }
 967        });
 968
 969        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 970            scene.push_stacking_context(None, None);
 971            let cursor_row_layout =
 972                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
 973            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 974            let y = (position.row() + 1) as f32 * layout.position_map.line_height - scroll_top;
 975            let mut list_origin = content_origin + vec2f(x, y);
 976            let list_width = context_menu.size().x();
 977            let list_height = context_menu.size().y();
 978
 979            // Snap the right edge of the list to the right edge of the window if
 980            // its horizontal bounds overflow.
 981            if list_origin.x() + list_width > cx.window_size().x() {
 982                list_origin.set_x((cx.window_size().x() - list_width).max(0.));
 983            }
 984
 985            if list_origin.y() + list_height > bounds.max_y() {
 986                list_origin.set_y(list_origin.y() - layout.position_map.line_height - list_height);
 987            }
 988
 989            context_menu.paint(
 990                scene,
 991                list_origin,
 992                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 993                editor,
 994                cx,
 995            );
 996
 997            scene.pop_stacking_context();
 998        }
 999
1000        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
1001            scene.push_stacking_context(None, None);
1002
1003            // This is safe because we check on layout whether the required row is available
1004            let hovered_row_layout =
1005                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
1006
1007            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
1008            // height. This is the size we will use to decide whether to render popovers above or below
1009            // the hovered line.
1010            let first_size = hover_popovers[0].size();
1011            let height_to_reserve = first_size.y()
1012                + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.position_map.line_height;
1013
1014            // Compute Hovered Point
1015            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
1016            let y = position.row() as f32 * layout.position_map.line_height - scroll_top;
1017            let hovered_point = content_origin + vec2f(x, y);
1018
1019            if hovered_point.y() - height_to_reserve > 0.0 {
1020                // There is enough space above. Render popovers above the hovered point
1021                let mut current_y = hovered_point.y();
1022                for hover_popover in hover_popovers {
1023                    let size = hover_popover.size();
1024                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
1025
1026                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
1027                    if x_out_of_bounds < 0.0 {
1028                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
1029                    }
1030
1031                    hover_popover.paint(
1032                        scene,
1033                        popover_origin,
1034                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
1035                        editor,
1036                        cx,
1037                    );
1038
1039                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
1040                }
1041            } else {
1042                // There is not enough space above. Render popovers below the hovered point
1043                let mut current_y = hovered_point.y() + layout.position_map.line_height;
1044                for hover_popover in hover_popovers {
1045                    let size = hover_popover.size();
1046                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
1047
1048                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
1049                    if x_out_of_bounds < 0.0 {
1050                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
1051                    }
1052
1053                    hover_popover.paint(
1054                        scene,
1055                        popover_origin,
1056                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
1057                        editor,
1058                        cx,
1059                    );
1060
1061                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
1062                }
1063            }
1064
1065            scene.pop_stacking_context();
1066        }
1067
1068        scene.pop_layer();
1069    }
1070
1071    fn scrollbar_left(&self, bounds: &RectF) -> f32 {
1072        bounds.max_x() - self.style.theme.scrollbar.width
1073    }
1074
1075    fn paint_scrollbar(
1076        &mut self,
1077        scene: &mut SceneBuilder,
1078        bounds: RectF,
1079        layout: &mut LayoutState,
1080        cx: &mut ViewContext<Editor>,
1081        editor: &Editor,
1082    ) {
1083        enum ScrollbarMouseHandlers {}
1084        if layout.mode != EditorMode::Full {
1085            return;
1086        }
1087
1088        let style = &self.style.theme.scrollbar;
1089
1090        let top = bounds.min_y();
1091        let bottom = bounds.max_y();
1092        let right = bounds.max_x();
1093        let left = self.scrollbar_left(&bounds);
1094        let row_range = &layout.scrollbar_row_range;
1095        let max_row = layout.max_row as f32 + (row_range.end - row_range.start);
1096
1097        let mut height = bounds.height();
1098        let mut first_row_y_offset = 0.0;
1099
1100        // Impose a minimum height on the scrollbar thumb
1101        let row_height = height / max_row;
1102        let min_thumb_height =
1103            style.min_height_factor * cx.font_cache.line_height(self.style.text.font_size);
1104        let thumb_height = (row_range.end - row_range.start) * row_height;
1105        if thumb_height < min_thumb_height {
1106            first_row_y_offset = (min_thumb_height - thumb_height) / 2.0;
1107            height -= min_thumb_height - thumb_height;
1108        }
1109
1110        let y_for_row = |row: f32| -> f32 { top + first_row_y_offset + row * row_height };
1111
1112        let thumb_top = y_for_row(row_range.start) - first_row_y_offset;
1113        let thumb_bottom = y_for_row(row_range.end) + first_row_y_offset;
1114        let track_bounds = RectF::from_points(vec2f(left, top), vec2f(right, bottom));
1115        let thumb_bounds = RectF::from_points(vec2f(left, thumb_top), vec2f(right, thumb_bottom));
1116
1117        if layout.show_scrollbars {
1118            scene.push_quad(Quad {
1119                bounds: track_bounds,
1120                border: style.track.border,
1121                background: style.track.background_color,
1122                ..Default::default()
1123            });
1124            let scrollbar_settings = settings::get::<EditorSettings>(cx).scrollbar;
1125            let theme = theme::current(cx);
1126            let scrollbar_theme = &theme.editor.scrollbar;
1127            if layout.is_singleton && scrollbar_settings.selections {
1128                let start_anchor = Anchor::min();
1129                let end_anchor = Anchor::max();
1130                let color = scrollbar_theme.selections;
1131                let border = Border {
1132                    width: 1.,
1133                    color: style.thumb.border.color,
1134                    overlay: false,
1135                    top: false,
1136                    right: true,
1137                    bottom: false,
1138                    left: true,
1139                };
1140                let mut push_region = |start: DisplayPoint, end: DisplayPoint| {
1141                    let start_y = y_for_row(start.row() as f32);
1142                    let mut end_y = y_for_row(end.row() as f32);
1143                    if end_y - start_y < 1. {
1144                        end_y = start_y + 1.;
1145                    }
1146                    let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
1147
1148                    scene.push_quad(Quad {
1149                        bounds,
1150                        background: Some(color),
1151                        border,
1152                        corner_radii: style.thumb.corner_radii.into(),
1153                    })
1154                };
1155                let background_ranges = editor
1156                    .background_highlight_row_ranges::<crate::items::BufferSearchHighlights>(
1157                        start_anchor..end_anchor,
1158                        &layout.position_map.snapshot,
1159                        50000,
1160                    );
1161                for row in background_ranges {
1162                    let start = row.start();
1163                    let end = row.end();
1164                    push_region(*start, *end);
1165                }
1166            }
1167
1168            if layout.is_singleton && scrollbar_settings.git_diff {
1169                let diff_style = scrollbar_theme.git.clone();
1170                for hunk in layout
1171                    .position_map
1172                    .snapshot
1173                    .buffer_snapshot
1174                    .git_diff_hunks_in_range(0..(max_row.floor() as u32))
1175                {
1176                    let start_display = Point::new(hunk.buffer_range.start, 0)
1177                        .to_display_point(&layout.position_map.snapshot.display_snapshot);
1178                    let end_display = Point::new(hunk.buffer_range.end, 0)
1179                        .to_display_point(&layout.position_map.snapshot.display_snapshot);
1180                    let start_y = y_for_row(start_display.row() as f32);
1181                    let mut end_y = if hunk.buffer_range.start == hunk.buffer_range.end {
1182                        y_for_row((end_display.row() + 1) as f32)
1183                    } else {
1184                        y_for_row((end_display.row()) as f32)
1185                    };
1186
1187                    if end_y - start_y < 1. {
1188                        end_y = start_y + 1.;
1189                    }
1190                    let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
1191
1192                    let color = match hunk.status() {
1193                        DiffHunkStatus::Added => diff_style.inserted,
1194                        DiffHunkStatus::Modified => diff_style.modified,
1195                        DiffHunkStatus::Removed => diff_style.deleted,
1196                    };
1197
1198                    let border = Border {
1199                        width: 1.,
1200                        color: style.thumb.border.color,
1201                        overlay: false,
1202                        top: false,
1203                        right: true,
1204                        bottom: false,
1205                        left: true,
1206                    };
1207
1208                    scene.push_quad(Quad {
1209                        bounds,
1210                        background: Some(color),
1211                        border,
1212                        corner_radii: style.thumb.corner_radii.into(),
1213                    })
1214                }
1215            }
1216
1217            scene.push_quad(Quad {
1218                bounds: thumb_bounds,
1219                border: style.thumb.border,
1220                background: style.thumb.background_color,
1221                corner_radii: style.thumb.corner_radii.into(),
1222            });
1223        }
1224
1225        scene.push_cursor_region(CursorRegion {
1226            bounds: track_bounds,
1227            style: CursorStyle::Arrow,
1228        });
1229        scene.push_mouse_region(
1230            MouseRegion::new::<ScrollbarMouseHandlers>(cx.view_id(), cx.view_id(), track_bounds)
1231                .on_move(move |event, editor: &mut Editor, cx| {
1232                    if event.pressed_button.is_none() {
1233                        editor.scroll_manager.show_scrollbar(cx);
1234                    }
1235                })
1236                .on_down(MouseButton::Left, {
1237                    let row_range = row_range.clone();
1238                    move |event, editor: &mut Editor, cx| {
1239                        let y = event.position.y();
1240                        if y < thumb_top || thumb_bottom < y {
1241                            let center_row = ((y - top) * max_row as f32 / height).round() as u32;
1242                            let top_row = center_row
1243                                .saturating_sub((row_range.end - row_range.start) as u32 / 2);
1244                            let mut position = editor.scroll_position(cx);
1245                            position.set_y(top_row as f32);
1246                            editor.set_scroll_position(position, cx);
1247                        } else {
1248                            editor.scroll_manager.show_scrollbar(cx);
1249                        }
1250                    }
1251                })
1252                .on_drag(MouseButton::Left, {
1253                    move |event, editor: &mut Editor, cx| {
1254                        if event.end {
1255                            return;
1256                        }
1257
1258                        let y = event.prev_mouse_position.y();
1259                        let new_y = event.position.y();
1260                        if thumb_top < y && y < thumb_bottom {
1261                            let mut position = editor.scroll_position(cx);
1262                            position.set_y(position.y() + (new_y - y) * (max_row as f32) / height);
1263                            if position.y() < 0.0 {
1264                                position.set_y(0.);
1265                            }
1266                            editor.set_scroll_position(position, cx);
1267                        }
1268                    }
1269                }),
1270        );
1271    }
1272
1273    #[allow(clippy::too_many_arguments)]
1274    fn paint_highlighted_range(
1275        &self,
1276        scene: &mut SceneBuilder,
1277        range: Range<DisplayPoint>,
1278        color: Color,
1279        corner_radius: f32,
1280        line_end_overshoot: f32,
1281        layout: &LayoutState,
1282        content_origin: Vector2F,
1283        scroll_top: f32,
1284        scroll_left: f32,
1285        bounds: RectF,
1286    ) {
1287        let start_row = layout.visible_display_row_range.start;
1288        let end_row = layout.visible_display_row_range.end;
1289        if range.start != range.end {
1290            let row_range = if range.end.column() == 0 {
1291                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
1292            } else {
1293                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
1294            };
1295
1296            let highlighted_range = HighlightedRange {
1297                color,
1298                line_height: layout.position_map.line_height,
1299                corner_radius,
1300                start_y: content_origin.y()
1301                    + row_range.start as f32 * layout.position_map.line_height
1302                    - scroll_top,
1303                lines: row_range
1304                    .into_iter()
1305                    .map(|row| {
1306                        let line_layout =
1307                            &layout.position_map.line_layouts[(row - start_row) as usize].line;
1308                        HighlightedRangeLine {
1309                            start_x: if row == range.start.row() {
1310                                content_origin.x()
1311                                    + line_layout.x_for_index(range.start.column() as usize)
1312                                    - scroll_left
1313                            } else {
1314                                content_origin.x() - scroll_left
1315                            },
1316                            end_x: if row == range.end.row() {
1317                                content_origin.x()
1318                                    + line_layout.x_for_index(range.end.column() as usize)
1319                                    - scroll_left
1320                            } else {
1321                                content_origin.x() + line_layout.width() + line_end_overshoot
1322                                    - scroll_left
1323                            },
1324                        }
1325                    })
1326                    .collect(),
1327            };
1328
1329            highlighted_range.paint(bounds, scene);
1330        }
1331    }
1332
1333    fn paint_blocks(
1334        &mut self,
1335        scene: &mut SceneBuilder,
1336        bounds: RectF,
1337        visible_bounds: RectF,
1338        layout: &mut LayoutState,
1339        editor: &mut Editor,
1340        cx: &mut PaintContext<Editor>,
1341    ) {
1342        let scroll_position = layout.position_map.snapshot.scroll_position();
1343        let scroll_left = scroll_position.x() * layout.position_map.em_width;
1344        let scroll_top = scroll_position.y() * layout.position_map.line_height;
1345
1346        for block in &mut layout.blocks {
1347            let mut origin = bounds.origin()
1348                + vec2f(
1349                    0.,
1350                    block.row as f32 * layout.position_map.line_height - scroll_top,
1351                );
1352            if !matches!(block.style, BlockStyle::Sticky) {
1353                origin += vec2f(-scroll_left, 0.);
1354            }
1355            block
1356                .element
1357                .paint(scene, origin, visible_bounds, editor, cx);
1358        }
1359    }
1360
1361    fn column_pixels(&self, column: usize, cx: &ViewContext<Editor>) -> f32 {
1362        let style = &self.style;
1363
1364        cx.text_layout_cache()
1365            .layout_str(
1366                " ".repeat(column).as_str(),
1367                style.text.font_size,
1368                &[(
1369                    column,
1370                    RunStyle {
1371                        font_id: style.text.font_id,
1372                        color: Color::black(),
1373                        underline: Default::default(),
1374                    },
1375                )],
1376            )
1377            .width()
1378    }
1379
1380    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &ViewContext<Editor>) -> f32 {
1381        let digit_count = (snapshot.max_buffer_row() as f32 + 1.).log10().floor() as usize + 1;
1382        self.column_pixels(digit_count, cx)
1383    }
1384
1385    //Folds contained in a hunk are ignored apart from shrinking visual size
1386    //If a fold contains any hunks then that fold line is marked as modified
1387    fn layout_git_gutters(
1388        &self,
1389        display_rows: Range<u32>,
1390        snapshot: &EditorSnapshot,
1391    ) -> Vec<DisplayDiffHunk> {
1392        let buffer_snapshot = &snapshot.buffer_snapshot;
1393
1394        let buffer_start_row = DisplayPoint::new(display_rows.start, 0)
1395            .to_point(snapshot)
1396            .row;
1397        let buffer_end_row = DisplayPoint::new(display_rows.end, 0)
1398            .to_point(snapshot)
1399            .row;
1400
1401        buffer_snapshot
1402            .git_diff_hunks_in_range(buffer_start_row..buffer_end_row)
1403            .map(|hunk| diff_hunk_to_display(hunk, snapshot))
1404            .dedup()
1405            .collect()
1406    }
1407
1408    fn layout_line_numbers(
1409        &self,
1410        rows: Range<u32>,
1411        active_rows: &BTreeMap<u32, bool>,
1412        is_singleton: bool,
1413        snapshot: &EditorSnapshot,
1414        cx: &ViewContext<Editor>,
1415    ) -> (
1416        Vec<Option<text_layout::Line>>,
1417        Vec<Option<(FoldStatus, BufferRow, bool)>>,
1418    ) {
1419        let style = &self.style;
1420        let include_line_numbers = snapshot.mode == EditorMode::Full;
1421        let mut line_number_layouts = Vec::with_capacity(rows.len());
1422        let mut fold_statuses = Vec::with_capacity(rows.len());
1423        let mut line_number = String::new();
1424        for (ix, row) in snapshot
1425            .buffer_rows(rows.start)
1426            .take((rows.end - rows.start) as usize)
1427            .enumerate()
1428        {
1429            let display_row = rows.start + ix as u32;
1430            let (active, color) = if active_rows.contains_key(&display_row) {
1431                (true, style.line_number_active)
1432            } else {
1433                (false, style.line_number)
1434            };
1435            if let Some(buffer_row) = row {
1436                if include_line_numbers {
1437                    line_number.clear();
1438                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
1439                    line_number_layouts.push(Some(cx.text_layout_cache().layout_str(
1440                        &line_number,
1441                        style.text.font_size,
1442                        &[(
1443                            line_number.len(),
1444                            RunStyle {
1445                                font_id: style.text.font_id,
1446                                color,
1447                                underline: Default::default(),
1448                            },
1449                        )],
1450                    )));
1451                    fold_statuses.push(
1452                        is_singleton
1453                            .then(|| {
1454                                snapshot
1455                                    .fold_for_line(buffer_row)
1456                                    .map(|fold_status| (fold_status, buffer_row, active))
1457                            })
1458                            .flatten(),
1459                    )
1460                }
1461            } else {
1462                fold_statuses.push(None);
1463                line_number_layouts.push(None);
1464            }
1465        }
1466
1467        (line_number_layouts, fold_statuses)
1468    }
1469
1470    fn layout_lines(
1471        &mut self,
1472        rows: Range<u32>,
1473        line_number_layouts: &[Option<Line>],
1474        snapshot: &EditorSnapshot,
1475        cx: &ViewContext<Editor>,
1476    ) -> Vec<LineWithInvisibles> {
1477        if rows.start >= rows.end {
1478            return Vec::new();
1479        }
1480
1481        // When the editor is empty and unfocused, then show the placeholder.
1482        if snapshot.is_empty() {
1483            let placeholder_style = self
1484                .style
1485                .placeholder_text
1486                .as_ref()
1487                .unwrap_or(&self.style.text);
1488            let placeholder_text = snapshot.placeholder_text();
1489            let placeholder_lines = placeholder_text
1490                .as_ref()
1491                .map_or("", AsRef::as_ref)
1492                .split('\n')
1493                .skip(rows.start as usize)
1494                .chain(iter::repeat(""))
1495                .take(rows.len());
1496            placeholder_lines
1497                .map(|line| {
1498                    cx.text_layout_cache().layout_str(
1499                        line,
1500                        placeholder_style.font_size,
1501                        &[(
1502                            line.len(),
1503                            RunStyle {
1504                                font_id: placeholder_style.font_id,
1505                                color: placeholder_style.color,
1506                                underline: Default::default(),
1507                            },
1508                        )],
1509                    )
1510                })
1511                .map(|line| LineWithInvisibles {
1512                    line,
1513                    invisibles: Vec::new(),
1514                })
1515                .collect()
1516        } else {
1517            let style = &self.style;
1518            let chunks = snapshot
1519                .chunks(
1520                    rows.clone(),
1521                    true,
1522                    Some(style.theme.hint),
1523                    Some(style.theme.suggestion),
1524                )
1525                .map(|chunk| {
1526                    let mut highlight_style = chunk
1527                        .syntax_highlight_id
1528                        .and_then(|id| id.style(&style.syntax));
1529
1530                    if let Some(chunk_highlight) = chunk.highlight_style {
1531                        if let Some(highlight_style) = highlight_style.as_mut() {
1532                            highlight_style.highlight(chunk_highlight);
1533                        } else {
1534                            highlight_style = Some(chunk_highlight);
1535                        }
1536                    }
1537
1538                    let mut diagnostic_highlight = HighlightStyle::default();
1539
1540                    if chunk.is_unnecessary {
1541                        diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
1542                    }
1543
1544                    if let Some(severity) = chunk.diagnostic_severity {
1545                        // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
1546                        if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
1547                            let diagnostic_style = super::diagnostic_style(severity, true, style);
1548                            diagnostic_highlight.underline = Some(Underline {
1549                                color: Some(diagnostic_style.message.text.color),
1550                                thickness: 1.0.into(),
1551                                squiggly: true,
1552                            });
1553                        }
1554                    }
1555
1556                    if let Some(highlight_style) = highlight_style.as_mut() {
1557                        highlight_style.highlight(diagnostic_highlight);
1558                    } else {
1559                        highlight_style = Some(diagnostic_highlight);
1560                    }
1561
1562                    HighlightedChunk {
1563                        chunk: chunk.text,
1564                        style: highlight_style,
1565                        is_tab: chunk.is_tab,
1566                    }
1567                });
1568
1569            LineWithInvisibles::from_chunks(
1570                chunks,
1571                &style.text,
1572                cx.text_layout_cache(),
1573                cx.font_cache(),
1574                MAX_LINE_LEN,
1575                rows.len() as usize,
1576                line_number_layouts,
1577                snapshot.mode,
1578            )
1579        }
1580    }
1581
1582    #[allow(clippy::too_many_arguments)]
1583    fn layout_blocks(
1584        &mut self,
1585        rows: Range<u32>,
1586        snapshot: &EditorSnapshot,
1587        editor_width: f32,
1588        scroll_width: f32,
1589        gutter_padding: f32,
1590        gutter_width: f32,
1591        em_width: f32,
1592        text_x: f32,
1593        line_height: f32,
1594        style: &EditorStyle,
1595        line_layouts: &[LineWithInvisibles],
1596        editor: &mut Editor,
1597        cx: &mut LayoutContext<Editor>,
1598    ) -> (f32, Vec<BlockLayout>) {
1599        let mut block_id = 0;
1600        let scroll_x = snapshot.scroll_anchor.offset.x();
1601        let (fixed_blocks, non_fixed_blocks) = snapshot
1602            .blocks_in_range(rows.clone())
1603            .partition::<Vec<_>, _>(|(_, block)| match block {
1604                TransformBlock::ExcerptHeader { .. } => false,
1605                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
1606            });
1607        let mut render_block = |block: &TransformBlock, width: f32, block_id: usize| {
1608            let mut element = match block {
1609                TransformBlock::Custom(block) => {
1610                    let align_to = block
1611                        .position()
1612                        .to_point(&snapshot.buffer_snapshot)
1613                        .to_display_point(snapshot);
1614                    let anchor_x = text_x
1615                        + if rows.contains(&align_to.row()) {
1616                            line_layouts[(align_to.row() - rows.start) as usize]
1617                                .line
1618                                .x_for_index(align_to.column() as usize)
1619                        } else {
1620                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache())
1621                                .x_for_index(align_to.column() as usize)
1622                        };
1623
1624                    block.render(&mut BlockContext {
1625                        view_context: cx,
1626                        anchor_x,
1627                        gutter_padding,
1628                        line_height,
1629                        scroll_x,
1630                        gutter_width,
1631                        em_width,
1632                        block_id,
1633                    })
1634                }
1635                TransformBlock::ExcerptHeader {
1636                    id,
1637                    buffer,
1638                    range,
1639                    starts_new_buffer,
1640                    ..
1641                } => {
1642                    let tooltip_style = theme::current(cx).tooltip.clone();
1643                    let include_root = editor
1644                        .project
1645                        .as_ref()
1646                        .map(|project| project.read(cx).visible_worktrees(cx).count() > 1)
1647                        .unwrap_or_default();
1648                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
1649                        let jump_path = ProjectPath {
1650                            worktree_id: file.worktree_id(cx),
1651                            path: file.path.clone(),
1652                        };
1653                        let jump_anchor = range
1654                            .primary
1655                            .as_ref()
1656                            .map_or(range.context.start, |primary| primary.start);
1657                        let jump_position = language::ToPoint::to_point(&jump_anchor, buffer);
1658
1659                        enum JumpIcon {}
1660                        MouseEventHandler::new::<JumpIcon, _>((*id).into(), cx, |state, _| {
1661                            let style = style.jump_icon.style_for(state);
1662                            Svg::new("icons/arrow_up_right_8.svg")
1663                                .with_color(style.color)
1664                                .constrained()
1665                                .with_width(style.icon_width)
1666                                .aligned()
1667                                .contained()
1668                                .with_style(style.container)
1669                                .constrained()
1670                                .with_width(style.button_width)
1671                                .with_height(style.button_width)
1672                        })
1673                        .with_cursor_style(CursorStyle::PointingHand)
1674                        .on_click(MouseButton::Left, move |_, editor, cx| {
1675                            if let Some(workspace) = editor
1676                                .workspace
1677                                .as_ref()
1678                                .and_then(|(workspace, _)| workspace.upgrade(cx))
1679                            {
1680                                workspace.update(cx, |workspace, cx| {
1681                                    Editor::jump(
1682                                        workspace,
1683                                        jump_path.clone(),
1684                                        jump_position,
1685                                        jump_anchor,
1686                                        cx,
1687                                    );
1688                                });
1689                            }
1690                        })
1691                        .with_tooltip::<JumpIcon>(
1692                            (*id).into(),
1693                            "Jump to Buffer".to_string(),
1694                            Some(Box::new(crate::OpenExcerpts)),
1695                            tooltip_style.clone(),
1696                            cx,
1697                        )
1698                        .aligned()
1699                        .flex_float()
1700                    });
1701
1702                    if *starts_new_buffer {
1703                        let editor_font_size = style.text.font_size;
1704                        let style = &style.diagnostic_path_header;
1705                        let font_size = (style.text_scale_factor * editor_font_size).round();
1706
1707                        let path = buffer.resolve_file_path(cx, include_root);
1708                        let mut filename = None;
1709                        let mut parent_path = None;
1710                        // Can't use .and_then() because `.file_name()` and `.parent()` return references :(
1711                        if let Some(path) = path {
1712                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1713                            parent_path =
1714                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1715                        }
1716
1717                        Flex::row()
1718                            .with_child(
1719                                Label::new(
1720                                    filename.unwrap_or_else(|| "untitled".to_string()),
1721                                    style.filename.text.clone().with_font_size(font_size),
1722                                )
1723                                .contained()
1724                                .with_style(style.filename.container)
1725                                .aligned(),
1726                            )
1727                            .with_children(parent_path.map(|path| {
1728                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1729                                    .contained()
1730                                    .with_style(style.path.container)
1731                                    .aligned()
1732                            }))
1733                            .with_children(jump_icon)
1734                            .contained()
1735                            .with_style(style.container)
1736                            .with_padding_left(gutter_padding)
1737                            .with_padding_right(gutter_padding)
1738                            .expanded()
1739                            .into_any_named("path header block")
1740                    } else {
1741                        let text_style = style.text.clone();
1742                        Flex::row()
1743                            .with_child(Label::new("⋯", text_style))
1744                            .with_children(jump_icon)
1745                            .contained()
1746                            .with_padding_left(gutter_padding)
1747                            .with_padding_right(gutter_padding)
1748                            .expanded()
1749                            .into_any_named("collapsed context")
1750                    }
1751                }
1752            };
1753
1754            element.layout(
1755                SizeConstraint {
1756                    min: Vector2F::zero(),
1757                    max: vec2f(width, block.height() as f32 * line_height),
1758                },
1759                editor,
1760                cx,
1761            );
1762            element
1763        };
1764
1765        let mut fixed_block_max_width = 0f32;
1766        let mut blocks = Vec::new();
1767        for (row, block) in fixed_blocks {
1768            let element = render_block(block, f32::INFINITY, block_id);
1769            block_id += 1;
1770            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1771            blocks.push(BlockLayout {
1772                row,
1773                element,
1774                style: BlockStyle::Fixed,
1775            });
1776        }
1777        for (row, block) in non_fixed_blocks {
1778            let style = match block {
1779                TransformBlock::Custom(block) => block.style(),
1780                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1781            };
1782            let width = match style {
1783                BlockStyle::Sticky => editor_width,
1784                BlockStyle::Flex => editor_width
1785                    .max(fixed_block_max_width)
1786                    .max(gutter_width + scroll_width),
1787                BlockStyle::Fixed => unreachable!(),
1788            };
1789            let element = render_block(block, width, block_id);
1790            block_id += 1;
1791            blocks.push(BlockLayout {
1792                row,
1793                element,
1794                style,
1795            });
1796        }
1797        (
1798            scroll_width.max(fixed_block_max_width - gutter_width),
1799            blocks,
1800        )
1801    }
1802}
1803
1804struct HighlightedChunk<'a> {
1805    chunk: &'a str,
1806    style: Option<HighlightStyle>,
1807    is_tab: bool,
1808}
1809
1810#[derive(Debug)]
1811pub struct LineWithInvisibles {
1812    pub line: Line,
1813    invisibles: Vec<Invisible>,
1814}
1815
1816impl LineWithInvisibles {
1817    fn from_chunks<'a>(
1818        chunks: impl Iterator<Item = HighlightedChunk<'a>>,
1819        text_style: &TextStyle,
1820        text_layout_cache: &TextLayoutCache,
1821        font_cache: &Arc<FontCache>,
1822        max_line_len: usize,
1823        max_line_count: usize,
1824        line_number_layouts: &[Option<Line>],
1825        editor_mode: EditorMode,
1826    ) -> Vec<Self> {
1827        let mut layouts = Vec::with_capacity(max_line_count);
1828        let mut line = String::new();
1829        let mut invisibles = Vec::new();
1830        let mut styles = Vec::new();
1831        let mut non_whitespace_added = false;
1832        let mut row = 0;
1833        let mut line_exceeded_max_len = false;
1834        for highlighted_chunk in chunks.chain([HighlightedChunk {
1835            chunk: "\n",
1836            style: None,
1837            is_tab: false,
1838        }]) {
1839            for (ix, mut line_chunk) in highlighted_chunk.chunk.split('\n').enumerate() {
1840                if ix > 0 {
1841                    layouts.push(Self {
1842                        line: text_layout_cache.layout_str(&line, text_style.font_size, &styles),
1843                        invisibles: invisibles.drain(..).collect(),
1844                    });
1845
1846                    line.clear();
1847                    styles.clear();
1848                    row += 1;
1849                    line_exceeded_max_len = false;
1850                    non_whitespace_added = false;
1851                    if row == max_line_count {
1852                        return layouts;
1853                    }
1854                }
1855
1856                if !line_chunk.is_empty() && !line_exceeded_max_len {
1857                    let text_style = if let Some(style) = highlighted_chunk.style {
1858                        text_style
1859                            .clone()
1860                            .highlight(style, font_cache)
1861                            .map(Cow::Owned)
1862                            .unwrap_or_else(|_| Cow::Borrowed(text_style))
1863                    } else {
1864                        Cow::Borrowed(text_style)
1865                    };
1866
1867                    if line.len() + line_chunk.len() > max_line_len {
1868                        let mut chunk_len = max_line_len - line.len();
1869                        while !line_chunk.is_char_boundary(chunk_len) {
1870                            chunk_len -= 1;
1871                        }
1872                        line_chunk = &line_chunk[..chunk_len];
1873                        line_exceeded_max_len = true;
1874                    }
1875
1876                    styles.push((
1877                        line_chunk.len(),
1878                        RunStyle {
1879                            font_id: text_style.font_id,
1880                            color: text_style.color,
1881                            underline: text_style.underline,
1882                        },
1883                    ));
1884
1885                    if editor_mode == EditorMode::Full {
1886                        // Line wrap pads its contents with fake whitespaces,
1887                        // avoid printing them
1888                        let inside_wrapped_string = line_number_layouts
1889                            .get(row)
1890                            .and_then(|layout| layout.as_ref())
1891                            .is_none();
1892                        if highlighted_chunk.is_tab {
1893                            if non_whitespace_added || !inside_wrapped_string {
1894                                invisibles.push(Invisible::Tab {
1895                                    line_start_offset: line.len(),
1896                                });
1897                            }
1898                        } else {
1899                            invisibles.extend(
1900                                line_chunk
1901                                    .chars()
1902                                    .enumerate()
1903                                    .filter(|(_, line_char)| {
1904                                        let is_whitespace = line_char.is_whitespace();
1905                                        non_whitespace_added |= !is_whitespace;
1906                                        is_whitespace
1907                                            && (non_whitespace_added || !inside_wrapped_string)
1908                                    })
1909                                    .map(|(whitespace_index, _)| Invisible::Whitespace {
1910                                        line_offset: line.len() + whitespace_index,
1911                                    }),
1912                            )
1913                        }
1914                    }
1915
1916                    line.push_str(line_chunk);
1917                }
1918            }
1919        }
1920
1921        layouts
1922    }
1923
1924    fn draw(
1925        &self,
1926        layout: &LayoutState,
1927        row: u32,
1928        scroll_top: f32,
1929        scene: &mut SceneBuilder,
1930        content_origin: Vector2F,
1931        scroll_left: f32,
1932        visible_text_bounds: RectF,
1933        whitespace_setting: ShowWhitespaceSetting,
1934        selection_ranges: &[Range<DisplayPoint>],
1935        visible_bounds: RectF,
1936        cx: &mut ViewContext<Editor>,
1937    ) {
1938        let line_height = layout.position_map.line_height;
1939        let line_y = row as f32 * line_height - scroll_top;
1940
1941        self.line.paint(
1942            scene,
1943            content_origin + vec2f(-scroll_left, line_y),
1944            visible_text_bounds,
1945            line_height,
1946            cx,
1947        );
1948
1949        self.draw_invisibles(
1950            &selection_ranges,
1951            layout,
1952            content_origin,
1953            scroll_left,
1954            line_y,
1955            row,
1956            scene,
1957            visible_bounds,
1958            line_height,
1959            whitespace_setting,
1960            cx,
1961        );
1962    }
1963
1964    fn draw_invisibles(
1965        &self,
1966        selection_ranges: &[Range<DisplayPoint>],
1967        layout: &LayoutState,
1968        content_origin: Vector2F,
1969        scroll_left: f32,
1970        line_y: f32,
1971        row: u32,
1972        scene: &mut SceneBuilder,
1973        visible_bounds: RectF,
1974        line_height: f32,
1975        whitespace_setting: ShowWhitespaceSetting,
1976        cx: &mut ViewContext<Editor>,
1977    ) {
1978        let allowed_invisibles_regions = match whitespace_setting {
1979            ShowWhitespaceSetting::None => return,
1980            ShowWhitespaceSetting::Selection => Some(selection_ranges),
1981            ShowWhitespaceSetting::All => None,
1982        };
1983
1984        for invisible in &self.invisibles {
1985            let (&token_offset, invisible_symbol) = match invisible {
1986                Invisible::Tab { line_start_offset } => (line_start_offset, &layout.tab_invisible),
1987                Invisible::Whitespace { line_offset } => (line_offset, &layout.space_invisible),
1988            };
1989
1990            let x_offset = self.line.x_for_index(token_offset);
1991            let invisible_offset =
1992                (layout.position_map.em_width - invisible_symbol.width()).max(0.0) / 2.0;
1993            let origin = content_origin + vec2f(-scroll_left + x_offset + invisible_offset, line_y);
1994
1995            if let Some(allowed_regions) = allowed_invisibles_regions {
1996                let invisible_point = DisplayPoint::new(row, token_offset as u32);
1997                if !allowed_regions
1998                    .iter()
1999                    .any(|region| region.start <= invisible_point && invisible_point < region.end)
2000                {
2001                    continue;
2002                }
2003            }
2004            invisible_symbol.paint(scene, origin, visible_bounds, line_height, cx);
2005        }
2006    }
2007}
2008
2009#[derive(Debug, Clone, Copy, PartialEq, Eq)]
2010enum Invisible {
2011    Tab { line_start_offset: usize },
2012    Whitespace { line_offset: usize },
2013}
2014
2015impl Element<Editor> for EditorElement {
2016    type LayoutState = LayoutState;
2017    type PaintState = ();
2018
2019    fn layout(
2020        &mut self,
2021        constraint: SizeConstraint,
2022        editor: &mut Editor,
2023        cx: &mut LayoutContext<Editor>,
2024    ) -> (Vector2F, Self::LayoutState) {
2025        let mut size = constraint.max;
2026        if size.x().is_infinite() {
2027            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
2028        }
2029
2030        let snapshot = editor.snapshot(cx);
2031        let style = self.style.clone();
2032
2033        let line_height = (style.text.font_size * style.line_height_scalar).round();
2034
2035        let gutter_padding;
2036        let gutter_width;
2037        let gutter_margin;
2038        if snapshot.show_gutter {
2039            let em_width = style.text.em_width(cx.font_cache());
2040            gutter_padding = (em_width * style.gutter_padding_factor).round();
2041            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
2042            gutter_margin = -style.text.descent(cx.font_cache());
2043        } else {
2044            gutter_padding = 0.0;
2045            gutter_width = 0.0;
2046            gutter_margin = 0.0;
2047        };
2048
2049        let text_width = size.x() - gutter_width;
2050        let em_width = style.text.em_width(cx.font_cache());
2051        let em_advance = style.text.em_advance(cx.font_cache());
2052        let overscroll = vec2f(em_width, 0.);
2053        let snapshot = {
2054            editor.set_visible_line_count(size.y() / line_height, cx);
2055
2056            let editor_width = text_width - gutter_margin - overscroll.x() - em_width;
2057            let wrap_width = match editor.soft_wrap_mode(cx) {
2058                SoftWrap::None => (MAX_LINE_LEN / 2) as f32 * em_advance,
2059                SoftWrap::EditorWidth => editor_width,
2060                SoftWrap::Column(column) => editor_width.min(column as f32 * em_advance),
2061            };
2062
2063            if editor.set_wrap_width(Some(wrap_width), cx) {
2064                editor.snapshot(cx)
2065            } else {
2066                snapshot
2067            }
2068        };
2069
2070        let wrap_guides = editor
2071            .wrap_guides(cx)
2072            .iter()
2073            .map(|(guide, active)| (self.column_pixels(*guide, cx), *active))
2074            .collect();
2075
2076        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
2077        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
2078            size.set_y(
2079                scroll_height
2080                    .min(constraint.max_along(Axis::Vertical))
2081                    .max(constraint.min_along(Axis::Vertical))
2082                    .max(line_height)
2083                    .min(line_height * max_lines as f32),
2084            )
2085        } else if let EditorMode::SingleLine = snapshot.mode {
2086            size.set_y(line_height.max(constraint.min_along(Axis::Vertical)))
2087        } else if size.y().is_infinite() {
2088            size.set_y(scroll_height);
2089        }
2090        let gutter_size = vec2f(gutter_width, size.y());
2091        let text_size = vec2f(text_width, size.y());
2092
2093        let autoscroll_horizontally = editor.autoscroll_vertically(size.y(), line_height, cx);
2094        let mut snapshot = editor.snapshot(cx);
2095
2096        let scroll_position = snapshot.scroll_position();
2097        // The scroll position is a fractional point, the whole number of which represents
2098        // the top of the window in terms of display rows.
2099        let start_row = scroll_position.y() as u32;
2100        let height_in_lines = size.y() / line_height;
2101        let max_row = snapshot.max_point().row();
2102
2103        // Add 1 to ensure selections bleed off screen
2104        let end_row = 1 + cmp::min(
2105            (scroll_position.y() + height_in_lines).ceil() as u32,
2106            max_row,
2107        );
2108
2109        let start_anchor = if start_row == 0 {
2110            Anchor::min()
2111        } else {
2112            snapshot
2113                .buffer_snapshot
2114                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
2115        };
2116        let end_anchor = if end_row > max_row {
2117            Anchor::max()
2118        } else {
2119            snapshot
2120                .buffer_snapshot
2121                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
2122        };
2123
2124        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
2125        let mut active_rows = BTreeMap::new();
2126        let mut fold_ranges = Vec::new();
2127        let is_singleton = editor.is_singleton(cx);
2128
2129        let highlighted_rows = editor.highlighted_rows();
2130        let theme = theme::current(cx);
2131        let highlighted_ranges = editor.background_highlights_in_range(
2132            start_anchor..end_anchor,
2133            &snapshot.display_snapshot,
2134            theme.as_ref(),
2135        );
2136
2137        fold_ranges.extend(
2138            snapshot
2139                .folds_in_range(start_anchor..end_anchor)
2140                .map(|anchor| {
2141                    let start = anchor.start.to_point(&snapshot.buffer_snapshot);
2142                    (
2143                        start.row,
2144                        start.to_display_point(&snapshot.display_snapshot)
2145                            ..anchor.end.to_display_point(&snapshot),
2146                    )
2147                }),
2148        );
2149
2150        let mut remote_selections = HashMap::default();
2151        for (replica_id, line_mode, cursor_shape, selection) in snapshot
2152            .buffer_snapshot
2153            .remote_selections_in_range(&(start_anchor..end_anchor))
2154        {
2155            // The local selections match the leader's selections.
2156            if Some(replica_id) == editor.leader_replica_id {
2157                continue;
2158            }
2159            remote_selections
2160                .entry(replica_id)
2161                .or_insert(Vec::new())
2162                .push(SelectionLayout::new(
2163                    selection,
2164                    line_mode,
2165                    cursor_shape,
2166                    &snapshot.display_snapshot,
2167                    false,
2168                ));
2169        }
2170        selections.extend(remote_selections);
2171
2172        let mut newest_selection_head = None;
2173
2174        if editor.show_local_selections {
2175            let mut local_selections: Vec<Selection<Point>> = editor
2176                .selections
2177                .disjoint_in_range(start_anchor..end_anchor, cx);
2178            local_selections.extend(editor.selections.pending(cx));
2179            let mut layouts = Vec::new();
2180            let newest = editor.selections.newest(cx);
2181            for selection in local_selections.drain(..) {
2182                let is_empty = selection.start == selection.end;
2183                let is_newest = selection == newest;
2184
2185                let layout = SelectionLayout::new(
2186                    selection,
2187                    editor.selections.line_mode,
2188                    editor.cursor_shape,
2189                    &snapshot.display_snapshot,
2190                    is_newest,
2191                );
2192                if is_newest {
2193                    newest_selection_head = Some(layout.head);
2194                }
2195
2196                for row in cmp::max(layout.active_rows.start, start_row)
2197                    ..=cmp::min(layout.active_rows.end, end_row)
2198                {
2199                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
2200                    *contains_non_empty_selection |= !is_empty;
2201                }
2202                layouts.push(layout);
2203            }
2204
2205            // Render the local selections in the leader's color when following.
2206            let local_replica_id = editor
2207                .leader_replica_id
2208                .unwrap_or_else(|| editor.replica_id(cx));
2209
2210            selections.push((local_replica_id, layouts));
2211        }
2212
2213        let scrollbar_settings = &settings::get::<EditorSettings>(cx).scrollbar;
2214        let show_scrollbars = match scrollbar_settings.show {
2215            ShowScrollbar::Auto => {
2216                // Git
2217                (is_singleton && scrollbar_settings.git_diff && snapshot.buffer_snapshot.has_git_diffs())
2218                ||
2219                // Selections
2220                (is_singleton && scrollbar_settings.selections && !highlighted_ranges.is_empty())
2221                // Scrollmanager
2222                || editor.scroll_manager.scrollbars_visible()
2223            }
2224            ShowScrollbar::System => editor.scroll_manager.scrollbars_visible(),
2225            ShowScrollbar::Always => true,
2226            ShowScrollbar::Never => false,
2227        };
2228
2229        let fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)> = fold_ranges
2230            .into_iter()
2231            .map(|(id, fold)| {
2232                let color = self
2233                    .style
2234                    .folds
2235                    .ellipses
2236                    .background
2237                    .style_for(&mut cx.mouse_state::<FoldMarkers>(id as usize))
2238                    .color;
2239
2240                (id, fold, color)
2241            })
2242            .collect();
2243
2244        let (line_number_layouts, fold_statuses) = self.layout_line_numbers(
2245            start_row..end_row,
2246            &active_rows,
2247            is_singleton,
2248            &snapshot,
2249            cx,
2250        );
2251
2252        let display_hunks = self.layout_git_gutters(start_row..end_row, &snapshot);
2253
2254        let scrollbar_row_range = scroll_position.y()..(scroll_position.y() + height_in_lines);
2255
2256        let mut max_visible_line_width = 0.0;
2257        let line_layouts =
2258            self.layout_lines(start_row..end_row, &line_number_layouts, &snapshot, cx);
2259        for line_with_invisibles in &line_layouts {
2260            if line_with_invisibles.line.width() > max_visible_line_width {
2261                max_visible_line_width = line_with_invisibles.line.width();
2262            }
2263        }
2264
2265        let style = self.style.clone();
2266        let longest_line_width = layout_line(
2267            snapshot.longest_row(),
2268            &snapshot,
2269            &style,
2270            cx.text_layout_cache(),
2271        )
2272        .width();
2273        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
2274        let em_width = style.text.em_width(cx.font_cache());
2275        let (scroll_width, blocks) = self.layout_blocks(
2276            start_row..end_row,
2277            &snapshot,
2278            size.x(),
2279            scroll_width,
2280            gutter_padding,
2281            gutter_width,
2282            em_width,
2283            gutter_width + gutter_margin,
2284            line_height,
2285            &style,
2286            &line_layouts,
2287            editor,
2288            cx,
2289        );
2290
2291        let scroll_max = vec2f(
2292            ((scroll_width - text_size.x()) / em_width).max(0.0),
2293            max_row as f32,
2294        );
2295
2296        let clamped = editor.scroll_manager.clamp_scroll_left(scroll_max.x());
2297
2298        let autoscrolled = if autoscroll_horizontally {
2299            editor.autoscroll_horizontally(
2300                start_row,
2301                text_size.x(),
2302                scroll_width,
2303                em_width,
2304                &line_layouts,
2305                cx,
2306            )
2307        } else {
2308            false
2309        };
2310
2311        if clamped || autoscrolled {
2312            snapshot = editor.snapshot(cx);
2313        }
2314
2315        let style = editor.style(cx);
2316
2317        let mut context_menu = None;
2318        let mut code_actions_indicator = None;
2319        if let Some(newest_selection_head) = newest_selection_head {
2320            if (start_row..end_row).contains(&newest_selection_head.row()) {
2321                if editor.context_menu_visible() {
2322                    context_menu =
2323                        editor.render_context_menu(newest_selection_head, style.clone(), cx);
2324                }
2325
2326                let active = matches!(
2327                    editor.context_menu,
2328                    Some(crate::ContextMenu::CodeActions(_))
2329                );
2330
2331                code_actions_indicator = editor
2332                    .render_code_actions_indicator(&style, active, cx)
2333                    .map(|indicator| (newest_selection_head.row(), indicator));
2334            }
2335        }
2336
2337        let visible_rows = start_row..start_row + line_layouts.len() as u32;
2338        let mut hover = editor
2339            .hover_state
2340            .render(&snapshot, &style, visible_rows, cx);
2341        let mode = editor.mode;
2342
2343        let mut fold_indicators = editor.render_fold_indicators(
2344            fold_statuses,
2345            &style,
2346            editor.gutter_hovered,
2347            line_height,
2348            gutter_margin,
2349            cx,
2350        );
2351
2352        if let Some((_, context_menu)) = context_menu.as_mut() {
2353            context_menu.layout(
2354                SizeConstraint {
2355                    min: Vector2F::zero(),
2356                    max: vec2f(
2357                        cx.window_size().x() * 0.7,
2358                        (12. * line_height).min((size.y() - line_height) / 2.),
2359                    ),
2360                },
2361                editor,
2362                cx,
2363            );
2364        }
2365
2366        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
2367            indicator.layout(
2368                SizeConstraint::strict_along(
2369                    Axis::Vertical,
2370                    line_height * style.code_actions.vertical_scale,
2371                ),
2372                editor,
2373                cx,
2374            );
2375        }
2376
2377        for fold_indicator in fold_indicators.iter_mut() {
2378            if let Some(indicator) = fold_indicator.as_mut() {
2379                indicator.layout(
2380                    SizeConstraint::strict_along(
2381                        Axis::Vertical,
2382                        line_height * style.code_actions.vertical_scale,
2383                    ),
2384                    editor,
2385                    cx,
2386                );
2387            }
2388        }
2389
2390        if let Some((_, hover_popovers)) = hover.as_mut() {
2391            for hover_popover in hover_popovers.iter_mut() {
2392                hover_popover.layout(
2393                    SizeConstraint {
2394                        min: Vector2F::zero(),
2395                        max: vec2f(
2396                            (120. * em_width) // Default size
2397                                .min(size.x() / 2.) // Shrink to half of the editor width
2398                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
2399                            (16. * line_height) // Default size
2400                                .min(size.y() / 2.) // Shrink to half of the editor height
2401                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
2402                        ),
2403                    },
2404                    editor,
2405                    cx,
2406                );
2407            }
2408        }
2409
2410        let invisible_symbol_font_size = self.style.text.font_size / 2.0;
2411        let invisible_symbol_style = RunStyle {
2412            color: self.style.whitespace,
2413            font_id: self.style.text.font_id,
2414            underline: Default::default(),
2415        };
2416
2417        (
2418            size,
2419            LayoutState {
2420                mode,
2421                position_map: Arc::new(PositionMap {
2422                    size,
2423                    scroll_max,
2424                    line_layouts,
2425                    line_height,
2426                    em_width,
2427                    em_advance,
2428                    snapshot,
2429                }),
2430                visible_display_row_range: start_row..end_row,
2431                wrap_guides,
2432                gutter_size,
2433                gutter_padding,
2434                text_size,
2435                scrollbar_row_range,
2436                show_scrollbars,
2437                is_singleton,
2438                max_row,
2439                gutter_margin,
2440                active_rows,
2441                highlighted_rows,
2442                highlighted_ranges,
2443                fold_ranges,
2444                line_number_layouts,
2445                display_hunks,
2446                blocks,
2447                selections,
2448                context_menu,
2449                code_actions_indicator,
2450                fold_indicators,
2451                tab_invisible: cx.text_layout_cache().layout_str(
2452                    "→",
2453                    invisible_symbol_font_size,
2454                    &[("→".len(), invisible_symbol_style)],
2455                ),
2456                space_invisible: cx.text_layout_cache().layout_str(
2457                    "•",
2458                    invisible_symbol_font_size,
2459                    &[("•".len(), invisible_symbol_style)],
2460                ),
2461                hover_popovers: hover,
2462            },
2463        )
2464    }
2465
2466    fn paint(
2467        &mut self,
2468        scene: &mut SceneBuilder,
2469        bounds: RectF,
2470        visible_bounds: RectF,
2471        layout: &mut Self::LayoutState,
2472        editor: &mut Editor,
2473        cx: &mut PaintContext<Editor>,
2474    ) -> Self::PaintState {
2475        let visible_bounds = bounds.intersection(visible_bounds).unwrap_or_default();
2476        scene.push_layer(Some(visible_bounds));
2477
2478        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
2479        let text_bounds = RectF::new(
2480            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2481            layout.text_size,
2482        );
2483
2484        Self::attach_mouse_handlers(
2485            scene,
2486            &layout.position_map,
2487            layout.hover_popovers.is_some(),
2488            visible_bounds,
2489            text_bounds,
2490            gutter_bounds,
2491            bounds,
2492            cx,
2493        );
2494
2495        self.paint_background(scene, gutter_bounds, text_bounds, layout);
2496        if layout.gutter_size.x() > 0. {
2497            self.paint_gutter(scene, gutter_bounds, visible_bounds, layout, editor, cx);
2498        }
2499        self.paint_text(scene, text_bounds, visible_bounds, layout, editor, cx);
2500
2501        scene.push_layer(Some(bounds));
2502        if !layout.blocks.is_empty() {
2503            self.paint_blocks(scene, bounds, visible_bounds, layout, editor, cx);
2504        }
2505        self.paint_scrollbar(scene, bounds, layout, cx, &editor);
2506        scene.pop_layer();
2507
2508        scene.pop_layer();
2509    }
2510
2511    fn rect_for_text_range(
2512        &self,
2513        range_utf16: Range<usize>,
2514        bounds: RectF,
2515        _: RectF,
2516        layout: &Self::LayoutState,
2517        _: &Self::PaintState,
2518        _: &Editor,
2519        _: &ViewContext<Editor>,
2520    ) -> Option<RectF> {
2521        let text_bounds = RectF::new(
2522            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2523            layout.text_size,
2524        );
2525        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
2526        let scroll_position = layout.position_map.snapshot.scroll_position();
2527        let start_row = scroll_position.y() as u32;
2528        let scroll_top = scroll_position.y() * layout.position_map.line_height;
2529        let scroll_left = scroll_position.x() * layout.position_map.em_width;
2530
2531        let range_start = OffsetUtf16(range_utf16.start)
2532            .to_display_point(&layout.position_map.snapshot.display_snapshot);
2533        if range_start.row() < start_row {
2534            return None;
2535        }
2536
2537        let line = &layout
2538            .position_map
2539            .line_layouts
2540            .get((range_start.row() - start_row) as usize)?
2541            .line;
2542        let range_start_x = line.x_for_index(range_start.column() as usize);
2543        let range_start_y = range_start.row() as f32 * layout.position_map.line_height;
2544        Some(RectF::new(
2545            content_origin
2546                + vec2f(
2547                    range_start_x,
2548                    range_start_y + layout.position_map.line_height,
2549                )
2550                - vec2f(scroll_left, scroll_top),
2551            vec2f(
2552                layout.position_map.em_width,
2553                layout.position_map.line_height,
2554            ),
2555        ))
2556    }
2557
2558    fn debug(
2559        &self,
2560        bounds: RectF,
2561        _: &Self::LayoutState,
2562        _: &Self::PaintState,
2563        _: &Editor,
2564        _: &ViewContext<Editor>,
2565    ) -> json::Value {
2566        json!({
2567            "type": "BufferElement",
2568            "bounds": bounds.to_json()
2569        })
2570    }
2571}
2572
2573type BufferRow = u32;
2574
2575pub struct LayoutState {
2576    position_map: Arc<PositionMap>,
2577    gutter_size: Vector2F,
2578    gutter_padding: f32,
2579    gutter_margin: f32,
2580    text_size: Vector2F,
2581    mode: EditorMode,
2582    wrap_guides: SmallVec<[(f32, bool); 2]>,
2583    visible_display_row_range: Range<u32>,
2584    active_rows: BTreeMap<u32, bool>,
2585    highlighted_rows: Option<Range<u32>>,
2586    line_number_layouts: Vec<Option<text_layout::Line>>,
2587    display_hunks: Vec<DisplayDiffHunk>,
2588    blocks: Vec<BlockLayout>,
2589    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
2590    fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)>,
2591    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
2592    scrollbar_row_range: Range<f32>,
2593    show_scrollbars: bool,
2594    is_singleton: bool,
2595    max_row: u32,
2596    context_menu: Option<(DisplayPoint, AnyElement<Editor>)>,
2597    code_actions_indicator: Option<(u32, AnyElement<Editor>)>,
2598    hover_popovers: Option<(DisplayPoint, Vec<AnyElement<Editor>>)>,
2599    fold_indicators: Vec<Option<AnyElement<Editor>>>,
2600    tab_invisible: Line,
2601    space_invisible: Line,
2602}
2603
2604struct PositionMap {
2605    size: Vector2F,
2606    line_height: f32,
2607    scroll_max: Vector2F,
2608    em_width: f32,
2609    em_advance: f32,
2610    line_layouts: Vec<LineWithInvisibles>,
2611    snapshot: EditorSnapshot,
2612}
2613
2614impl PositionMap {
2615    /// Returns two display points:
2616    /// 1. The nearest *valid* position in the editor
2617    /// 2. An unclipped, potentially *invalid* position that maps directly to
2618    ///    the given pixel position.
2619    fn point_for_position(
2620        &self,
2621        text_bounds: RectF,
2622        position: Vector2F,
2623    ) -> (DisplayPoint, DisplayPoint) {
2624        let scroll_position = self.snapshot.scroll_position();
2625        let position = position - text_bounds.origin();
2626        let y = position.y().max(0.0).min(self.size.y());
2627        let x = position.x() + (scroll_position.x() * self.em_width);
2628        let row = (y / self.line_height + scroll_position.y()) as u32;
2629        let (column, x_overshoot) = if let Some(line) = self
2630            .line_layouts
2631            .get(row as usize - scroll_position.y() as usize)
2632            .map(|line_with_spaces| &line_with_spaces.line)
2633        {
2634            if let Some(ix) = line.index_for_x(x) {
2635                (ix as u32, 0.0)
2636            } else {
2637                (line.len() as u32, 0f32.max(x - line.width()))
2638            }
2639        } else {
2640            (0, x)
2641        };
2642
2643        let mut target_point = DisplayPoint::new(row, column);
2644        let point = self.snapshot.clip_point(target_point, Bias::Left);
2645        *target_point.column_mut() += (x_overshoot / self.em_advance) as u32;
2646
2647        (point, target_point)
2648    }
2649}
2650
2651struct BlockLayout {
2652    row: u32,
2653    element: AnyElement<Editor>,
2654    style: BlockStyle,
2655}
2656
2657fn layout_line(
2658    row: u32,
2659    snapshot: &EditorSnapshot,
2660    style: &EditorStyle,
2661    layout_cache: &TextLayoutCache,
2662) -> text_layout::Line {
2663    let mut line = snapshot.line(row);
2664
2665    if line.len() > MAX_LINE_LEN {
2666        let mut len = MAX_LINE_LEN;
2667        while !line.is_char_boundary(len) {
2668            len -= 1;
2669        }
2670
2671        line.truncate(len);
2672    }
2673
2674    layout_cache.layout_str(
2675        &line,
2676        style.text.font_size,
2677        &[(
2678            snapshot.line_len(row) as usize,
2679            RunStyle {
2680                font_id: style.text.font_id,
2681                color: Color::black(),
2682                underline: Default::default(),
2683            },
2684        )],
2685    )
2686}
2687
2688#[derive(Debug)]
2689pub struct Cursor {
2690    origin: Vector2F,
2691    block_width: f32,
2692    line_height: f32,
2693    color: Color,
2694    shape: CursorShape,
2695    block_text: Option<Line>,
2696}
2697
2698impl Cursor {
2699    pub fn new(
2700        origin: Vector2F,
2701        block_width: f32,
2702        line_height: f32,
2703        color: Color,
2704        shape: CursorShape,
2705        block_text: Option<Line>,
2706    ) -> Cursor {
2707        Cursor {
2708            origin,
2709            block_width,
2710            line_height,
2711            color,
2712            shape,
2713            block_text,
2714        }
2715    }
2716
2717    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
2718        RectF::new(
2719            self.origin + origin,
2720            vec2f(self.block_width, self.line_height),
2721        )
2722    }
2723
2724    pub fn paint(&self, scene: &mut SceneBuilder, origin: Vector2F, cx: &mut WindowContext) {
2725        let bounds = match self.shape {
2726            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
2727            CursorShape::Block | CursorShape::Hollow => RectF::new(
2728                self.origin + origin,
2729                vec2f(self.block_width, self.line_height),
2730            ),
2731            CursorShape::Underscore => RectF::new(
2732                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
2733                vec2f(self.block_width, 2.0),
2734            ),
2735        };
2736
2737        //Draw background or border quad
2738        if matches!(self.shape, CursorShape::Hollow) {
2739            scene.push_quad(Quad {
2740                bounds,
2741                background: None,
2742                border: Border::all(1., self.color),
2743                corner_radii: Default::default(),
2744            });
2745        } else {
2746            scene.push_quad(Quad {
2747                bounds,
2748                background: Some(self.color),
2749                border: Default::default(),
2750                corner_radii: Default::default(),
2751            });
2752        }
2753
2754        if let Some(block_text) = &self.block_text {
2755            block_text.paint(scene, self.origin + origin, bounds, self.line_height, cx);
2756        }
2757    }
2758
2759    pub fn shape(&self) -> CursorShape {
2760        self.shape
2761    }
2762}
2763
2764#[derive(Debug)]
2765pub struct HighlightedRange {
2766    pub start_y: f32,
2767    pub line_height: f32,
2768    pub lines: Vec<HighlightedRangeLine>,
2769    pub color: Color,
2770    pub corner_radius: f32,
2771}
2772
2773#[derive(Debug)]
2774pub struct HighlightedRangeLine {
2775    pub start_x: f32,
2776    pub end_x: f32,
2777}
2778
2779impl HighlightedRange {
2780    pub fn paint(&self, bounds: RectF, scene: &mut SceneBuilder) {
2781        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
2782            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
2783            self.paint_lines(
2784                self.start_y + self.line_height,
2785                &self.lines[1..],
2786                bounds,
2787                scene,
2788            );
2789        } else {
2790            self.paint_lines(self.start_y, &self.lines, bounds, scene);
2791        }
2792    }
2793
2794    fn paint_lines(
2795        &self,
2796        start_y: f32,
2797        lines: &[HighlightedRangeLine],
2798        bounds: RectF,
2799        scene: &mut SceneBuilder,
2800    ) {
2801        if lines.is_empty() {
2802            return;
2803        }
2804
2805        let mut path = PathBuilder::new();
2806        let first_line = lines.first().unwrap();
2807        let last_line = lines.last().unwrap();
2808
2809        let first_top_left = vec2f(first_line.start_x, start_y);
2810        let first_top_right = vec2f(first_line.end_x, start_y);
2811
2812        let curve_height = vec2f(0., self.corner_radius);
2813        let curve_width = |start_x: f32, end_x: f32| {
2814            let max = (end_x - start_x) / 2.;
2815            let width = if max < self.corner_radius {
2816                max
2817            } else {
2818                self.corner_radius
2819            };
2820
2821            vec2f(width, 0.)
2822        };
2823
2824        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
2825        path.reset(first_top_right - top_curve_width);
2826        path.curve_to(first_top_right + curve_height, first_top_right);
2827
2828        let mut iter = lines.iter().enumerate().peekable();
2829        while let Some((ix, line)) = iter.next() {
2830            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
2831
2832            if let Some((_, next_line)) = iter.peek() {
2833                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
2834
2835                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
2836                    Ordering::Equal => {
2837                        path.line_to(bottom_right);
2838                    }
2839                    Ordering::Less => {
2840                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
2841                        path.line_to(bottom_right - curve_height);
2842                        if self.corner_radius > 0. {
2843                            path.curve_to(bottom_right - curve_width, bottom_right);
2844                        }
2845                        path.line_to(next_top_right + curve_width);
2846                        if self.corner_radius > 0. {
2847                            path.curve_to(next_top_right + curve_height, next_top_right);
2848                        }
2849                    }
2850                    Ordering::Greater => {
2851                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
2852                        path.line_to(bottom_right - curve_height);
2853                        if self.corner_radius > 0. {
2854                            path.curve_to(bottom_right + curve_width, bottom_right);
2855                        }
2856                        path.line_to(next_top_right - curve_width);
2857                        if self.corner_radius > 0. {
2858                            path.curve_to(next_top_right + curve_height, next_top_right);
2859                        }
2860                    }
2861                }
2862            } else {
2863                let curve_width = curve_width(line.start_x, line.end_x);
2864                path.line_to(bottom_right - curve_height);
2865                if self.corner_radius > 0. {
2866                    path.curve_to(bottom_right - curve_width, bottom_right);
2867                }
2868
2869                let bottom_left = vec2f(line.start_x, bottom_right.y());
2870                path.line_to(bottom_left + curve_width);
2871                if self.corner_radius > 0. {
2872                    path.curve_to(bottom_left - curve_height, bottom_left);
2873                }
2874            }
2875        }
2876
2877        if first_line.start_x > last_line.start_x {
2878            let curve_width = curve_width(last_line.start_x, first_line.start_x);
2879            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
2880            path.line_to(second_top_left + curve_height);
2881            if self.corner_radius > 0. {
2882                path.curve_to(second_top_left + curve_width, second_top_left);
2883            }
2884            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
2885            path.line_to(first_bottom_left - curve_width);
2886            if self.corner_radius > 0. {
2887                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
2888            }
2889        }
2890
2891        path.line_to(first_top_left + curve_height);
2892        if self.corner_radius > 0. {
2893            path.curve_to(first_top_left + top_curve_width, first_top_left);
2894        }
2895        path.line_to(first_top_right - top_curve_width);
2896
2897        scene.push_path(path.build(self.color, Some(bounds)));
2898    }
2899}
2900
2901fn position_to_display_point(
2902    position: Vector2F,
2903    text_bounds: RectF,
2904    position_map: &PositionMap,
2905) -> Option<DisplayPoint> {
2906    if text_bounds.contains_point(position) {
2907        let (point, target_point) = position_map.point_for_position(text_bounds, position);
2908        if point == target_point {
2909            Some(point)
2910        } else {
2911            None
2912        }
2913    } else {
2914        None
2915    }
2916}
2917
2918fn range_to_bounds(
2919    range: &Range<DisplayPoint>,
2920    content_origin: Vector2F,
2921    scroll_left: f32,
2922    scroll_top: f32,
2923    visible_row_range: &Range<u32>,
2924    line_end_overshoot: f32,
2925    position_map: &PositionMap,
2926) -> impl Iterator<Item = RectF> {
2927    let mut bounds: SmallVec<[RectF; 1]> = SmallVec::new();
2928
2929    if range.start == range.end {
2930        return bounds.into_iter();
2931    }
2932
2933    let start_row = visible_row_range.start;
2934    let end_row = visible_row_range.end;
2935
2936    let row_range = if range.end.column() == 0 {
2937        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
2938    } else {
2939        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
2940    };
2941
2942    let first_y =
2943        content_origin.y() + row_range.start as f32 * position_map.line_height - scroll_top;
2944
2945    for (idx, row) in row_range.enumerate() {
2946        let line_layout = &position_map.line_layouts[(row - start_row) as usize].line;
2947
2948        let start_x = if row == range.start.row() {
2949            content_origin.x() + line_layout.x_for_index(range.start.column() as usize)
2950                - scroll_left
2951        } else {
2952            content_origin.x() - scroll_left
2953        };
2954
2955        let end_x = if row == range.end.row() {
2956            content_origin.x() + line_layout.x_for_index(range.end.column() as usize) - scroll_left
2957        } else {
2958            content_origin.x() + line_layout.width() + line_end_overshoot - scroll_left
2959        };
2960
2961        bounds.push(RectF::from_points(
2962            vec2f(start_x, first_y + position_map.line_height * idx as f32),
2963            vec2f(end_x, first_y + position_map.line_height * (idx + 1) as f32),
2964        ))
2965    }
2966
2967    bounds.into_iter()
2968}
2969
2970pub fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
2971    delta.powf(1.5) / 100.0
2972}
2973
2974fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
2975    delta.powf(1.2) / 300.0
2976}
2977
2978#[cfg(test)]
2979mod tests {
2980    use super::*;
2981    use crate::{
2982        display_map::{BlockDisposition, BlockProperties},
2983        editor_tests::{init_test, update_test_language_settings},
2984        Editor, MultiBuffer,
2985    };
2986    use gpui::TestAppContext;
2987    use language::language_settings;
2988    use log::info;
2989    use std::{num::NonZeroU32, sync::Arc};
2990    use util::test::sample_text;
2991
2992    #[gpui::test]
2993    fn test_layout_line_numbers(cx: &mut TestAppContext) {
2994        init_test(cx, |_| {});
2995
2996        let editor = cx
2997            .add_window(|cx| {
2998                let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
2999                Editor::new(EditorMode::Full, buffer, None, None, cx)
3000            })
3001            .root(cx);
3002        let element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3003
3004        let layouts = editor.update(cx, |editor, cx| {
3005            let snapshot = editor.snapshot(cx);
3006            element
3007                .layout_line_numbers(0..6, &Default::default(), false, &snapshot, cx)
3008                .0
3009        });
3010        assert_eq!(layouts.len(), 6);
3011    }
3012
3013    #[gpui::test]
3014    async fn test_vim_visual_selections(cx: &mut TestAppContext) {
3015        init_test(cx, |_| {});
3016
3017        let editor = cx
3018            .add_window(|cx| {
3019                let buffer = MultiBuffer::build_simple(&(sample_text(6, 6, 'a') + "\n"), cx);
3020                Editor::new(EditorMode::Full, buffer, None, None, cx)
3021            })
3022            .root(cx);
3023        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3024        let (_, state) = editor.update(cx, |editor, cx| {
3025            editor.cursor_shape = CursorShape::Block;
3026            editor.change_selections(None, cx, |s| {
3027                s.select_ranges([
3028                    Point::new(0, 0)..Point::new(1, 0),
3029                    Point::new(3, 2)..Point::new(3, 3),
3030                    Point::new(5, 6)..Point::new(6, 0),
3031                ]);
3032            });
3033            let mut new_parents = Default::default();
3034            let mut notify_views_if_parents_change = Default::default();
3035            let mut layout_cx = LayoutContext::new(
3036                cx,
3037                &mut new_parents,
3038                &mut notify_views_if_parents_change,
3039                false,
3040            );
3041            element.layout(
3042                SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
3043                editor,
3044                &mut layout_cx,
3045            )
3046        });
3047        assert_eq!(state.selections.len(), 1);
3048        let local_selections = &state.selections[0].1;
3049        assert_eq!(local_selections.len(), 3);
3050        // moves cursor back one line
3051        assert_eq!(local_selections[0].head, DisplayPoint::new(0, 6));
3052        assert_eq!(
3053            local_selections[0].range,
3054            DisplayPoint::new(0, 0)..DisplayPoint::new(1, 0)
3055        );
3056
3057        // moves cursor back one column
3058        assert_eq!(
3059            local_selections[1].range,
3060            DisplayPoint::new(3, 2)..DisplayPoint::new(3, 3)
3061        );
3062        assert_eq!(local_selections[1].head, DisplayPoint::new(3, 2));
3063
3064        // leaves cursor on the max point
3065        assert_eq!(
3066            local_selections[2].range,
3067            DisplayPoint::new(5, 6)..DisplayPoint::new(6, 0)
3068        );
3069        assert_eq!(local_selections[2].head, DisplayPoint::new(6, 0));
3070
3071        // active lines does not include 1 (even though the range of the selection does)
3072        assert_eq!(
3073            state.active_rows.keys().cloned().collect::<Vec<u32>>(),
3074            vec![0, 3, 5, 6]
3075        );
3076
3077        // multi-buffer support
3078        // in DisplayPoint co-ordinates, this is what we're dealing with:
3079        //  0: [[file
3080        //  1:   header]]
3081        //  2: aaaaaa
3082        //  3: bbbbbb
3083        //  4: cccccc
3084        //  5:
3085        //  6: ...
3086        //  7: ffffff
3087        //  8: gggggg
3088        //  9: hhhhhh
3089        // 10:
3090        // 11: [[file
3091        // 12:   header]]
3092        // 13: bbbbbb
3093        // 14: cccccc
3094        // 15: dddddd
3095        let editor = cx
3096            .add_window(|cx| {
3097                let buffer = MultiBuffer::build_multi(
3098                    [
3099                        (
3100                            &(sample_text(8, 6, 'a') + "\n"),
3101                            vec![
3102                                Point::new(0, 0)..Point::new(3, 0),
3103                                Point::new(4, 0)..Point::new(7, 0),
3104                            ],
3105                        ),
3106                        (
3107                            &(sample_text(8, 6, 'a') + "\n"),
3108                            vec![Point::new(1, 0)..Point::new(3, 0)],
3109                        ),
3110                    ],
3111                    cx,
3112                );
3113                Editor::new(EditorMode::Full, buffer, None, None, cx)
3114            })
3115            .root(cx);
3116        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3117        let (_, state) = editor.update(cx, |editor, cx| {
3118            editor.cursor_shape = CursorShape::Block;
3119            editor.change_selections(None, cx, |s| {
3120                s.select_display_ranges([
3121                    DisplayPoint::new(4, 0)..DisplayPoint::new(7, 0),
3122                    DisplayPoint::new(10, 0)..DisplayPoint::new(13, 0),
3123                ]);
3124            });
3125            let mut new_parents = Default::default();
3126            let mut notify_views_if_parents_change = Default::default();
3127            let mut layout_cx = LayoutContext::new(
3128                cx,
3129                &mut new_parents,
3130                &mut notify_views_if_parents_change,
3131                false,
3132            );
3133            element.layout(
3134                SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
3135                editor,
3136                &mut layout_cx,
3137            )
3138        });
3139
3140        assert_eq!(state.selections.len(), 1);
3141        let local_selections = &state.selections[0].1;
3142        assert_eq!(local_selections.len(), 2);
3143
3144        // moves cursor on excerpt boundary back a line
3145        // and doesn't allow selection to bleed through
3146        assert_eq!(
3147            local_selections[0].range,
3148            DisplayPoint::new(4, 0)..DisplayPoint::new(6, 0)
3149        );
3150        assert_eq!(local_selections[0].head, DisplayPoint::new(5, 0));
3151
3152        // moves cursor on buffer boundary back two lines
3153        // and doesn't allow selection to bleed through
3154        assert_eq!(
3155            local_selections[1].range,
3156            DisplayPoint::new(10, 0)..DisplayPoint::new(11, 0)
3157        );
3158        assert_eq!(local_selections[1].head, DisplayPoint::new(10, 0));
3159    }
3160
3161    #[gpui::test]
3162    fn test_layout_with_placeholder_text_and_blocks(cx: &mut TestAppContext) {
3163        init_test(cx, |_| {});
3164
3165        let editor = cx
3166            .add_window(|cx| {
3167                let buffer = MultiBuffer::build_simple("", cx);
3168                Editor::new(EditorMode::Full, buffer, None, None, cx)
3169            })
3170            .root(cx);
3171
3172        editor.update(cx, |editor, cx| {
3173            editor.set_placeholder_text("hello", cx);
3174            editor.insert_blocks(
3175                [BlockProperties {
3176                    style: BlockStyle::Fixed,
3177                    disposition: BlockDisposition::Above,
3178                    height: 3,
3179                    position: Anchor::min(),
3180                    render: Arc::new(|_| Empty::new().into_any()),
3181                }],
3182                None,
3183                cx,
3184            );
3185
3186            // Blur the editor so that it displays placeholder text.
3187            cx.blur();
3188        });
3189
3190        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3191        let (size, mut state) = editor.update(cx, |editor, cx| {
3192            let mut new_parents = Default::default();
3193            let mut notify_views_if_parents_change = Default::default();
3194            let mut layout_cx = LayoutContext::new(
3195                cx,
3196                &mut new_parents,
3197                &mut notify_views_if_parents_change,
3198                false,
3199            );
3200            element.layout(
3201                SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
3202                editor,
3203                &mut layout_cx,
3204            )
3205        });
3206
3207        assert_eq!(state.position_map.line_layouts.len(), 4);
3208        assert_eq!(
3209            state
3210                .line_number_layouts
3211                .iter()
3212                .map(Option::is_some)
3213                .collect::<Vec<_>>(),
3214            &[false, false, false, true]
3215        );
3216
3217        // Don't panic.
3218        let mut scene = SceneBuilder::new(1.0);
3219        let bounds = RectF::new(Default::default(), size);
3220        editor.update(cx, |editor, cx| {
3221            element.paint(
3222                &mut scene,
3223                bounds,
3224                bounds,
3225                &mut state,
3226                editor,
3227                &mut PaintContext::new(cx),
3228            );
3229        });
3230    }
3231
3232    #[gpui::test]
3233    fn test_all_invisibles_drawing(cx: &mut TestAppContext) {
3234        const TAB_SIZE: u32 = 4;
3235
3236        let input_text = "\t \t|\t| a b";
3237        let expected_invisibles = vec![
3238            Invisible::Tab {
3239                line_start_offset: 0,
3240            },
3241            Invisible::Whitespace {
3242                line_offset: TAB_SIZE as usize,
3243            },
3244            Invisible::Tab {
3245                line_start_offset: TAB_SIZE as usize + 1,
3246            },
3247            Invisible::Tab {
3248                line_start_offset: TAB_SIZE as usize * 2 + 1,
3249            },
3250            Invisible::Whitespace {
3251                line_offset: TAB_SIZE as usize * 3 + 1,
3252            },
3253            Invisible::Whitespace {
3254                line_offset: TAB_SIZE as usize * 3 + 3,
3255            },
3256        ];
3257        assert_eq!(
3258            expected_invisibles.len(),
3259            input_text
3260                .chars()
3261                .filter(|initial_char| initial_char.is_whitespace())
3262                .count(),
3263            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
3264        );
3265
3266        init_test(cx, |s| {
3267            s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3268            s.defaults.tab_size = NonZeroU32::new(TAB_SIZE);
3269        });
3270
3271        let actual_invisibles =
3272            collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, 500.0);
3273
3274        assert_eq!(expected_invisibles, actual_invisibles);
3275    }
3276
3277    #[gpui::test]
3278    fn test_invisibles_dont_appear_in_certain_editors(cx: &mut TestAppContext) {
3279        init_test(cx, |s| {
3280            s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3281            s.defaults.tab_size = NonZeroU32::new(4);
3282        });
3283
3284        for editor_mode_without_invisibles in [
3285            EditorMode::SingleLine,
3286            EditorMode::AutoHeight { max_lines: 100 },
3287        ] {
3288            let invisibles = collect_invisibles_from_new_editor(
3289                cx,
3290                editor_mode_without_invisibles,
3291                "\t\t\t| | a b",
3292                500.0,
3293            );
3294            assert!(invisibles.is_empty(),
3295                "For editor mode {editor_mode_without_invisibles:?} no invisibles was expected but got {invisibles:?}");
3296        }
3297    }
3298
3299    #[gpui::test]
3300    fn test_wrapped_invisibles_drawing(cx: &mut TestAppContext) {
3301        let tab_size = 4;
3302        let input_text = "a\tbcd   ".repeat(9);
3303        let repeated_invisibles = [
3304            Invisible::Tab {
3305                line_start_offset: 1,
3306            },
3307            Invisible::Whitespace {
3308                line_offset: tab_size as usize + 3,
3309            },
3310            Invisible::Whitespace {
3311                line_offset: tab_size as usize + 4,
3312            },
3313            Invisible::Whitespace {
3314                line_offset: tab_size as usize + 5,
3315            },
3316        ];
3317        let expected_invisibles = std::iter::once(repeated_invisibles)
3318            .cycle()
3319            .take(9)
3320            .flatten()
3321            .collect::<Vec<_>>();
3322        assert_eq!(
3323            expected_invisibles.len(),
3324            input_text
3325                .chars()
3326                .filter(|initial_char| initial_char.is_whitespace())
3327                .count(),
3328            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
3329        );
3330        info!("Expected invisibles: {expected_invisibles:?}");
3331
3332        init_test(cx, |_| {});
3333
3334        // Put the same string with repeating whitespace pattern into editors of various size,
3335        // take deliberately small steps during resizing, to put all whitespace kinds near the wrap point.
3336        let resize_step = 10.0;
3337        let mut editor_width = 200.0;
3338        while editor_width <= 1000.0 {
3339            update_test_language_settings(cx, |s| {
3340                s.defaults.tab_size = NonZeroU32::new(tab_size);
3341                s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3342                s.defaults.preferred_line_length = Some(editor_width as u32);
3343                s.defaults.soft_wrap = Some(language_settings::SoftWrap::PreferredLineLength);
3344            });
3345
3346            let actual_invisibles =
3347                collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, editor_width);
3348
3349            // Whatever the editor size is, ensure it has the same invisible kinds in the same order
3350            // (no good guarantees about the offsets: wrapping could trigger padding and its tests should check the offsets).
3351            let mut i = 0;
3352            for (actual_index, actual_invisible) in actual_invisibles.iter().enumerate() {
3353                i = actual_index;
3354                match expected_invisibles.get(i) {
3355                    Some(expected_invisible) => match (expected_invisible, actual_invisible) {
3356                        (Invisible::Whitespace { .. }, Invisible::Whitespace { .. })
3357                        | (Invisible::Tab { .. }, Invisible::Tab { .. }) => {}
3358                        _ => {
3359                            panic!("At index {i}, expected invisible {expected_invisible:?} does not match actual {actual_invisible:?} by kind. Actual invisibles: {actual_invisibles:?}")
3360                        }
3361                    },
3362                    None => panic!("Unexpected extra invisible {actual_invisible:?} at index {i}"),
3363                }
3364            }
3365            let missing_expected_invisibles = &expected_invisibles[i + 1..];
3366            assert!(
3367                missing_expected_invisibles.is_empty(),
3368                "Missing expected invisibles after index {i}: {missing_expected_invisibles:?}"
3369            );
3370
3371            editor_width += resize_step;
3372        }
3373    }
3374
3375    fn collect_invisibles_from_new_editor(
3376        cx: &mut TestAppContext,
3377        editor_mode: EditorMode,
3378        input_text: &str,
3379        editor_width: f32,
3380    ) -> Vec<Invisible> {
3381        info!(
3382            "Creating editor with mode {editor_mode:?}, width {editor_width} and text '{input_text}'"
3383        );
3384        let editor = cx
3385            .add_window(|cx| {
3386                let buffer = MultiBuffer::build_simple(&input_text, cx);
3387                Editor::new(editor_mode, buffer, None, None, cx)
3388            })
3389            .root(cx);
3390
3391        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3392        let (_, layout_state) = editor.update(cx, |editor, cx| {
3393            editor.set_soft_wrap_mode(language_settings::SoftWrap::EditorWidth, cx);
3394            editor.set_wrap_width(Some(editor_width), cx);
3395
3396            let mut new_parents = Default::default();
3397            let mut notify_views_if_parents_change = Default::default();
3398            let mut layout_cx = LayoutContext::new(
3399                cx,
3400                &mut new_parents,
3401                &mut notify_views_if_parents_change,
3402                false,
3403            );
3404            element.layout(
3405                SizeConstraint::new(vec2f(editor_width, 500.), vec2f(editor_width, 500.)),
3406                editor,
3407                &mut layout_cx,
3408            )
3409        });
3410
3411        layout_state
3412            .position_map
3413            .line_layouts
3414            .iter()
3415            .map(|line_with_invisibles| &line_with_invisibles.invisibles)
3416            .flatten()
3417            .cloned()
3418            .collect()
3419    }
3420}