element.rs

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