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                    let mut cursor_column = cursor_position.column() as usize;
 851                    let mut cursor_row = cursor_position.row();
 852
 853                    // highlight the last character in a selection
 854                    if CursorShape::Block == selection.cursor_shape
 855                        && !selection.range.is_empty()
 856                        && !selection.reversed
 857                    {
 858                        if cursor_column > 0 {
 859                            cursor_column -= 1;
 860                        } else if cursor_row > 0
 861                            && cursor_position != layout.position_map.snapshot.max_point()
 862                        {
 863                            cursor_row -= 1;
 864                            cursor_column =
 865                                layout.position_map.snapshot.line_len(cursor_row) as usize;
 866                        }
 867                    }
 868                    dbg!(selection.head, cursor_row, cursor_column);
 869
 870                    if layout.visible_display_row_range.contains(&cursor_row) {
 871                        let cursor_row_layout = &layout.position_map.line_layouts
 872                            [(cursor_row - start_row) as usize]
 873                            .line;
 874
 875                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 876                        let mut block_width =
 877                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 878                        if block_width == 0.0 {
 879                            block_width = layout.position_map.em_width;
 880                        }
 881                        let block_text = if let CursorShape::Block = selection.cursor_shape {
 882                            layout
 883                                .position_map
 884                                .snapshot
 885                                .chars_at(DisplayPoint::new(
 886                                    cursor_row as u32,
 887                                    cursor_column as u32,
 888                                ))
 889                                .next()
 890                                .and_then(|(character, _)| {
 891                                    let font_id =
 892                                        cursor_row_layout.font_for_index(cursor_column)?;
 893                                    let text = character.to_string();
 894
 895                                    Some(cx.text_layout_cache().layout_str(
 896                                        &text,
 897                                        cursor_row_layout.font_size(),
 898                                        &[(
 899                                            text.len(),
 900                                            RunStyle {
 901                                                font_id,
 902                                                color: style.background,
 903                                                underline: Default::default(),
 904                                            },
 905                                        )],
 906                                    ))
 907                                })
 908                        } else {
 909                            None
 910                        };
 911
 912                        let x = cursor_character_x - scroll_left;
 913                        let y = cursor_row as f32 * layout.position_map.line_height - scroll_top;
 914                        if selection.is_newest {
 915                            editor.pixel_position_of_newest_cursor = Some(vec2f(
 916                                bounds.origin_x() + x + block_width / 2.,
 917                                bounds.origin_y() + y + layout.position_map.line_height / 2.,
 918                            ));
 919                        }
 920                        cursors.push(Cursor {
 921                            color: selection_style.cursor,
 922                            block_width,
 923                            origin: vec2f(x, y),
 924                            line_height: layout.position_map.line_height,
 925                            shape: selection.cursor_shape,
 926                            block_text,
 927                        });
 928                    }
 929                }
 930            }
 931        }
 932
 933        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 934            for (ix, line_with_invisibles) in layout.position_map.line_layouts.iter().enumerate() {
 935                let row = start_row + ix as u32;
 936                line_with_invisibles.draw(
 937                    layout,
 938                    row,
 939                    scroll_top,
 940                    scene,
 941                    content_origin,
 942                    scroll_left,
 943                    visible_text_bounds,
 944                    whitespace_setting,
 945                    &invisible_display_ranges,
 946                    visible_bounds,
 947                    cx,
 948                )
 949            }
 950        }
 951
 952        scene.paint_layer(Some(bounds), |scene| {
 953            for cursor in cursors {
 954                cursor.paint(scene, content_origin, cx);
 955            }
 956        });
 957
 958        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 959            scene.push_stacking_context(None, None);
 960            let cursor_row_layout =
 961                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
 962            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 963            let y = (position.row() + 1) as f32 * layout.position_map.line_height - scroll_top;
 964            let mut list_origin = content_origin + vec2f(x, y);
 965            let list_width = context_menu.size().x();
 966            let list_height = context_menu.size().y();
 967
 968            // Snap the right edge of the list to the right edge of the window if
 969            // its horizontal bounds overflow.
 970            if list_origin.x() + list_width > cx.window_size().x() {
 971                list_origin.set_x((cx.window_size().x() - list_width).max(0.));
 972            }
 973
 974            if list_origin.y() + list_height > bounds.max_y() {
 975                list_origin.set_y(list_origin.y() - layout.position_map.line_height - list_height);
 976            }
 977
 978            context_menu.paint(
 979                scene,
 980                list_origin,
 981                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 982                editor,
 983                cx,
 984            );
 985
 986            scene.pop_stacking_context();
 987        }
 988
 989        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
 990            scene.push_stacking_context(None, None);
 991
 992            // This is safe because we check on layout whether the required row is available
 993            let hovered_row_layout =
 994                &layout.position_map.line_layouts[(position.row() - start_row) as usize].line;
 995
 996            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
 997            // height. This is the size we will use to decide whether to render popovers above or below
 998            // the hovered line.
 999            let first_size = hover_popovers[0].size();
1000            let height_to_reserve = first_size.y()
1001                + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.position_map.line_height;
1002
1003            // Compute Hovered Point
1004            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
1005            let y = position.row() as f32 * layout.position_map.line_height - scroll_top;
1006            let hovered_point = content_origin + vec2f(x, y);
1007
1008            if hovered_point.y() - height_to_reserve > 0.0 {
1009                // There is enough space above. Render popovers above the hovered point
1010                let mut current_y = hovered_point.y();
1011                for hover_popover in hover_popovers {
1012                    let size = hover_popover.size();
1013                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
1014
1015                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
1016                    if x_out_of_bounds < 0.0 {
1017                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
1018                    }
1019
1020                    hover_popover.paint(
1021                        scene,
1022                        popover_origin,
1023                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
1024                        editor,
1025                        cx,
1026                    );
1027
1028                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
1029                }
1030            } else {
1031                // There is not enough space above. Render popovers below the hovered point
1032                let mut current_y = hovered_point.y() + layout.position_map.line_height;
1033                for hover_popover in hover_popovers {
1034                    let size = hover_popover.size();
1035                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
1036
1037                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
1038                    if x_out_of_bounds < 0.0 {
1039                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
1040                    }
1041
1042                    hover_popover.paint(
1043                        scene,
1044                        popover_origin,
1045                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
1046                        editor,
1047                        cx,
1048                    );
1049
1050                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
1051                }
1052            }
1053
1054            scene.pop_stacking_context();
1055        }
1056
1057        scene.pop_layer();
1058    }
1059
1060    fn paint_scrollbar(
1061        &mut self,
1062        scene: &mut SceneBuilder,
1063        bounds: RectF,
1064        layout: &mut LayoutState,
1065        cx: &mut ViewContext<Editor>,
1066        editor: &Editor,
1067    ) {
1068        enum ScrollbarMouseHandlers {}
1069        if layout.mode != EditorMode::Full {
1070            return;
1071        }
1072
1073        let style = &self.style.theme.scrollbar;
1074
1075        let top = bounds.min_y();
1076        let bottom = bounds.max_y();
1077        let right = bounds.max_x();
1078        let left = right - style.width;
1079        let row_range = &layout.scrollbar_row_range;
1080        let max_row = layout.max_row as f32 + (row_range.end - row_range.start);
1081
1082        let mut height = bounds.height();
1083        let mut first_row_y_offset = 0.0;
1084
1085        // Impose a minimum height on the scrollbar thumb
1086        let row_height = height / max_row;
1087        let min_thumb_height =
1088            style.min_height_factor * cx.font_cache.line_height(self.style.text.font_size);
1089        let thumb_height = (row_range.end - row_range.start) * row_height;
1090        if thumb_height < min_thumb_height {
1091            first_row_y_offset = (min_thumb_height - thumb_height) / 2.0;
1092            height -= min_thumb_height - thumb_height;
1093        }
1094
1095        let y_for_row = |row: f32| -> f32 { top + first_row_y_offset + row * row_height };
1096
1097        let thumb_top = y_for_row(row_range.start) - first_row_y_offset;
1098        let thumb_bottom = y_for_row(row_range.end) + first_row_y_offset;
1099        let track_bounds = RectF::from_points(vec2f(left, top), vec2f(right, bottom));
1100        let thumb_bounds = RectF::from_points(vec2f(left, thumb_top), vec2f(right, thumb_bottom));
1101
1102        if layout.show_scrollbars {
1103            scene.push_quad(Quad {
1104                bounds: track_bounds,
1105                border: style.track.border,
1106                background: style.track.background_color,
1107                ..Default::default()
1108            });
1109            let scrollbar_settings = settings::get::<EditorSettings>(cx).scrollbar;
1110            let theme = theme::current(cx);
1111            let scrollbar_theme = &theme.editor.scrollbar;
1112            if layout.is_singleton && scrollbar_settings.selections {
1113                let start_anchor = Anchor::min();
1114                let end_anchor = Anchor::max();
1115                let mut start_row = None;
1116                let mut end_row = None;
1117                let color = scrollbar_theme.selections;
1118                let border = Border {
1119                    width: 1.,
1120                    color: style.thumb.border.color,
1121                    overlay: false,
1122                    top: false,
1123                    right: true,
1124                    bottom: false,
1125                    left: true,
1126                };
1127                let mut push_region = |start, end| {
1128                    if let (Some(start_display), Some(end_display)) = (start, end) {
1129                        let start_y = y_for_row(start_display as f32);
1130                        let mut end_y = y_for_row(end_display as f32);
1131                        if end_y - start_y < 1. {
1132                            end_y = start_y + 1.;
1133                        }
1134                        let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
1135
1136                        scene.push_quad(Quad {
1137                            bounds,
1138                            background: Some(color),
1139                            border,
1140                            corner_radius: style.thumb.corner_radius,
1141                        })
1142                    }
1143                };
1144                for (row, _) in &editor
1145                    .background_highlights_in_range_for::<crate::items::BufferSearchHighlights>(
1146                        start_anchor..end_anchor,
1147                        &layout.position_map.snapshot,
1148                        &theme,
1149                    )
1150                {
1151                    let start_display = row.start;
1152                    let end_display = row.end;
1153
1154                    if start_row.is_none() {
1155                        assert_eq!(end_row, None);
1156                        start_row = Some(start_display.row());
1157                        end_row = Some(end_display.row());
1158                        continue;
1159                    }
1160                    if let Some(current_end) = end_row.as_mut() {
1161                        if start_display.row() > *current_end + 1 {
1162                            push_region(start_row, end_row);
1163                            start_row = Some(start_display.row());
1164                            end_row = Some(end_display.row());
1165                        } else {
1166                            // Merge two hunks.
1167                            *current_end = end_display.row();
1168                        }
1169                    } else {
1170                        unreachable!();
1171                    }
1172                }
1173                // We might still have a hunk that was not rendered (if there was a search hit on the last line)
1174                push_region(start_row, end_row);
1175            }
1176
1177            if layout.is_singleton && scrollbar_settings.git_diff {
1178                let diff_style = scrollbar_theme.git.clone();
1179                for hunk in layout
1180                    .position_map
1181                    .snapshot
1182                    .buffer_snapshot
1183                    .git_diff_hunks_in_range(0..(max_row.floor() as u32))
1184                {
1185                    let start_display = Point::new(hunk.buffer_range.start, 0)
1186                        .to_display_point(&layout.position_map.snapshot.display_snapshot);
1187                    let end_display = Point::new(hunk.buffer_range.end, 0)
1188                        .to_display_point(&layout.position_map.snapshot.display_snapshot);
1189                    let start_y = y_for_row(start_display.row() as f32);
1190                    let mut end_y = if hunk.buffer_range.start == hunk.buffer_range.end {
1191                        y_for_row((end_display.row() + 1) as f32)
1192                    } else {
1193                        y_for_row((end_display.row()) as f32)
1194                    };
1195
1196                    if end_y - start_y < 1. {
1197                        end_y = start_y + 1.;
1198                    }
1199                    let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
1200
1201                    let color = match hunk.status() {
1202                        DiffHunkStatus::Added => diff_style.inserted,
1203                        DiffHunkStatus::Modified => diff_style.modified,
1204                        DiffHunkStatus::Removed => diff_style.deleted,
1205                    };
1206
1207                    let border = Border {
1208                        width: 1.,
1209                        color: style.thumb.border.color,
1210                        overlay: false,
1211                        top: false,
1212                        right: true,
1213                        bottom: false,
1214                        left: true,
1215                    };
1216
1217                    scene.push_quad(Quad {
1218                        bounds,
1219                        background: Some(color),
1220                        border,
1221                        corner_radius: style.thumb.corner_radius,
1222                    })
1223                }
1224            }
1225
1226            scene.push_quad(Quad {
1227                bounds: thumb_bounds,
1228                border: style.thumb.border,
1229                background: style.thumb.background_color,
1230                corner_radius: style.thumb.corner_radius,
1231            });
1232        }
1233
1234        scene.push_cursor_region(CursorRegion {
1235            bounds: track_bounds,
1236            style: CursorStyle::Arrow,
1237        });
1238        scene.push_mouse_region(
1239            MouseRegion::new::<ScrollbarMouseHandlers>(cx.view_id(), cx.view_id(), track_bounds)
1240                .on_move(move |event, editor: &mut Editor, cx| {
1241                    if event.pressed_button.is_none() {
1242                        editor.scroll_manager.show_scrollbar(cx);
1243                    }
1244                })
1245                .on_down(MouseButton::Left, {
1246                    let row_range = row_range.clone();
1247                    move |event, editor: &mut Editor, cx| {
1248                        let y = event.position.y();
1249                        if y < thumb_top || thumb_bottom < y {
1250                            let center_row = ((y - top) * max_row as f32 / height).round() as u32;
1251                            let top_row = center_row
1252                                .saturating_sub((row_range.end - row_range.start) as u32 / 2);
1253                            let mut position = editor.scroll_position(cx);
1254                            position.set_y(top_row as f32);
1255                            editor.set_scroll_position(position, cx);
1256                        } else {
1257                            editor.scroll_manager.show_scrollbar(cx);
1258                        }
1259                    }
1260                })
1261                .on_drag(MouseButton::Left, {
1262                    move |event, editor: &mut Editor, cx| {
1263                        if event.end {
1264                            return;
1265                        }
1266
1267                        let y = event.prev_mouse_position.y();
1268                        let new_y = event.position.y();
1269                        if thumb_top < y && y < thumb_bottom {
1270                            let mut position = editor.scroll_position(cx);
1271                            position.set_y(position.y() + (new_y - y) * (max_row as f32) / height);
1272                            if position.y() < 0.0 {
1273                                position.set_y(0.);
1274                            }
1275                            editor.set_scroll_position(position, cx);
1276                        }
1277                    }
1278                }),
1279        );
1280    }
1281
1282    #[allow(clippy::too_many_arguments)]
1283    fn paint_highlighted_range(
1284        &self,
1285        scene: &mut SceneBuilder,
1286        range: Range<DisplayPoint>,
1287        color: Color,
1288        corner_radius: f32,
1289        line_end_overshoot: f32,
1290        layout: &LayoutState,
1291        content_origin: Vector2F,
1292        scroll_top: f32,
1293        scroll_left: f32,
1294        bounds: RectF,
1295    ) {
1296        let start_row = layout.visible_display_row_range.start;
1297        let end_row = layout.visible_display_row_range.end;
1298        if range.start != range.end {
1299            let row_range = if range.end.column() == 0 {
1300                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
1301            } else {
1302                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
1303            };
1304
1305            let highlighted_range = HighlightedRange {
1306                color,
1307                line_height: layout.position_map.line_height,
1308                corner_radius,
1309                start_y: content_origin.y()
1310                    + row_range.start as f32 * layout.position_map.line_height
1311                    - scroll_top,
1312                lines: row_range
1313                    .into_iter()
1314                    .map(|row| {
1315                        let line_layout =
1316                            &layout.position_map.line_layouts[(row - start_row) as usize].line;
1317                        HighlightedRangeLine {
1318                            start_x: if row == range.start.row() {
1319                                content_origin.x()
1320                                    + line_layout.x_for_index(range.start.column() as usize)
1321                                    - scroll_left
1322                            } else {
1323                                content_origin.x() - scroll_left
1324                            },
1325                            end_x: if row == range.end.row() {
1326                                content_origin.x()
1327                                    + line_layout.x_for_index(range.end.column() as usize)
1328                                    - scroll_left
1329                            } else {
1330                                content_origin.x() + line_layout.width() + line_end_overshoot
1331                                    - scroll_left
1332                            },
1333                        }
1334                    })
1335                    .collect(),
1336            };
1337
1338            highlighted_range.paint(bounds, scene);
1339        }
1340    }
1341
1342    fn paint_blocks(
1343        &mut self,
1344        scene: &mut SceneBuilder,
1345        bounds: RectF,
1346        visible_bounds: RectF,
1347        layout: &mut LayoutState,
1348        editor: &mut Editor,
1349        cx: &mut ViewContext<Editor>,
1350    ) {
1351        let scroll_position = layout.position_map.snapshot.scroll_position();
1352        let scroll_left = scroll_position.x() * layout.position_map.em_width;
1353        let scroll_top = scroll_position.y() * layout.position_map.line_height;
1354
1355        for block in &mut layout.blocks {
1356            let mut origin = bounds.origin()
1357                + vec2f(
1358                    0.,
1359                    block.row as f32 * layout.position_map.line_height - scroll_top,
1360                );
1361            if !matches!(block.style, BlockStyle::Sticky) {
1362                origin += vec2f(-scroll_left, 0.);
1363            }
1364            block
1365                .element
1366                .paint(scene, origin, visible_bounds, editor, cx);
1367        }
1368    }
1369
1370    fn column_pixels(&self, column: usize, cx: &ViewContext<Editor>) -> f32 {
1371        let style = &self.style;
1372
1373        cx.text_layout_cache()
1374            .layout_str(
1375                " ".repeat(column).as_str(),
1376                style.text.font_size,
1377                &[(
1378                    column,
1379                    RunStyle {
1380                        font_id: style.text.font_id,
1381                        color: Color::black(),
1382                        underline: Default::default(),
1383                    },
1384                )],
1385            )
1386            .width()
1387    }
1388
1389    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &ViewContext<Editor>) -> f32 {
1390        let digit_count = (snapshot.max_buffer_row() as f32 + 1.).log10().floor() as usize + 1;
1391        self.column_pixels(digit_count, cx)
1392    }
1393
1394    //Folds contained in a hunk are ignored apart from shrinking visual size
1395    //If a fold contains any hunks then that fold line is marked as modified
1396    fn layout_git_gutters(
1397        &self,
1398        display_rows: Range<u32>,
1399        snapshot: &EditorSnapshot,
1400    ) -> Vec<DisplayDiffHunk> {
1401        let buffer_snapshot = &snapshot.buffer_snapshot;
1402
1403        let buffer_start_row = DisplayPoint::new(display_rows.start, 0)
1404            .to_point(snapshot)
1405            .row;
1406        let buffer_end_row = DisplayPoint::new(display_rows.end, 0)
1407            .to_point(snapshot)
1408            .row;
1409
1410        buffer_snapshot
1411            .git_diff_hunks_in_range(buffer_start_row..buffer_end_row)
1412            .map(|hunk| diff_hunk_to_display(hunk, snapshot))
1413            .dedup()
1414            .collect()
1415    }
1416
1417    fn layout_line_numbers(
1418        &self,
1419        rows: Range<u32>,
1420        active_rows: &BTreeMap<u32, bool>,
1421        is_singleton: bool,
1422        snapshot: &EditorSnapshot,
1423        cx: &ViewContext<Editor>,
1424    ) -> (
1425        Vec<Option<text_layout::Line>>,
1426        Vec<Option<(FoldStatus, BufferRow, bool)>>,
1427    ) {
1428        let style = &self.style;
1429        let include_line_numbers = snapshot.mode == EditorMode::Full;
1430        let mut line_number_layouts = Vec::with_capacity(rows.len());
1431        let mut fold_statuses = Vec::with_capacity(rows.len());
1432        let mut line_number = String::new();
1433        for (ix, row) in snapshot
1434            .buffer_rows(rows.start)
1435            .take((rows.end - rows.start) as usize)
1436            .enumerate()
1437        {
1438            let display_row = rows.start + ix as u32;
1439            let (active, color) = if active_rows.contains_key(&display_row) {
1440                (true, style.line_number_active)
1441            } else {
1442                (false, style.line_number)
1443            };
1444            if let Some(buffer_row) = row {
1445                if include_line_numbers {
1446                    line_number.clear();
1447                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
1448                    line_number_layouts.push(Some(cx.text_layout_cache().layout_str(
1449                        &line_number,
1450                        style.text.font_size,
1451                        &[(
1452                            line_number.len(),
1453                            RunStyle {
1454                                font_id: style.text.font_id,
1455                                color,
1456                                underline: Default::default(),
1457                            },
1458                        )],
1459                    )));
1460                    fold_statuses.push(
1461                        is_singleton
1462                            .then(|| {
1463                                snapshot
1464                                    .fold_for_line(buffer_row)
1465                                    .map(|fold_status| (fold_status, buffer_row, active))
1466                            })
1467                            .flatten(),
1468                    )
1469                }
1470            } else {
1471                fold_statuses.push(None);
1472                line_number_layouts.push(None);
1473            }
1474        }
1475
1476        (line_number_layouts, fold_statuses)
1477    }
1478
1479    fn layout_lines(
1480        &mut self,
1481        rows: Range<u32>,
1482        line_number_layouts: &[Option<Line>],
1483        snapshot: &EditorSnapshot,
1484        cx: &ViewContext<Editor>,
1485    ) -> Vec<LineWithInvisibles> {
1486        if rows.start >= rows.end {
1487            return Vec::new();
1488        }
1489
1490        // When the editor is empty and unfocused, then show the placeholder.
1491        if snapshot.is_empty() {
1492            let placeholder_style = self
1493                .style
1494                .placeholder_text
1495                .as_ref()
1496                .unwrap_or(&self.style.text);
1497            let placeholder_text = snapshot.placeholder_text();
1498            let placeholder_lines = placeholder_text
1499                .as_ref()
1500                .map_or("", AsRef::as_ref)
1501                .split('\n')
1502                .skip(rows.start as usize)
1503                .chain(iter::repeat(""))
1504                .take(rows.len());
1505            placeholder_lines
1506                .map(|line| {
1507                    cx.text_layout_cache().layout_str(
1508                        line,
1509                        placeholder_style.font_size,
1510                        &[(
1511                            line.len(),
1512                            RunStyle {
1513                                font_id: placeholder_style.font_id,
1514                                color: placeholder_style.color,
1515                                underline: Default::default(),
1516                            },
1517                        )],
1518                    )
1519                })
1520                .map(|line| LineWithInvisibles {
1521                    line,
1522                    invisibles: Vec::new(),
1523                })
1524                .collect()
1525        } else {
1526            let style = &self.style;
1527            let chunks = snapshot
1528                .chunks(
1529                    rows.clone(),
1530                    true,
1531                    Some(style.theme.hint),
1532                    Some(style.theme.suggestion),
1533                )
1534                .map(|chunk| {
1535                    let mut highlight_style = chunk
1536                        .syntax_highlight_id
1537                        .and_then(|id| id.style(&style.syntax));
1538
1539                    if let Some(chunk_highlight) = chunk.highlight_style {
1540                        if let Some(highlight_style) = highlight_style.as_mut() {
1541                            highlight_style.highlight(chunk_highlight);
1542                        } else {
1543                            highlight_style = Some(chunk_highlight);
1544                        }
1545                    }
1546
1547                    let mut diagnostic_highlight = HighlightStyle::default();
1548
1549                    if chunk.is_unnecessary {
1550                        diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
1551                    }
1552
1553                    if let Some(severity) = chunk.diagnostic_severity {
1554                        // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
1555                        if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
1556                            let diagnostic_style = super::diagnostic_style(severity, true, style);
1557                            diagnostic_highlight.underline = Some(Underline {
1558                                color: Some(diagnostic_style.message.text.color),
1559                                thickness: 1.0.into(),
1560                                squiggly: true,
1561                            });
1562                        }
1563                    }
1564
1565                    if let Some(highlight_style) = highlight_style.as_mut() {
1566                        highlight_style.highlight(diagnostic_highlight);
1567                    } else {
1568                        highlight_style = Some(diagnostic_highlight);
1569                    }
1570
1571                    HighlightedChunk {
1572                        chunk: chunk.text,
1573                        style: highlight_style,
1574                        is_tab: chunk.is_tab,
1575                    }
1576                });
1577
1578            LineWithInvisibles::from_chunks(
1579                chunks,
1580                &style.text,
1581                cx.text_layout_cache(),
1582                cx.font_cache(),
1583                MAX_LINE_LEN,
1584                rows.len() as usize,
1585                line_number_layouts,
1586                snapshot.mode,
1587            )
1588        }
1589    }
1590
1591    #[allow(clippy::too_many_arguments)]
1592    fn layout_blocks(
1593        &mut self,
1594        rows: Range<u32>,
1595        snapshot: &EditorSnapshot,
1596        editor_width: f32,
1597        scroll_width: f32,
1598        gutter_padding: f32,
1599        gutter_width: f32,
1600        em_width: f32,
1601        text_x: f32,
1602        line_height: f32,
1603        style: &EditorStyle,
1604        line_layouts: &[LineWithInvisibles],
1605        editor: &mut Editor,
1606        cx: &mut LayoutContext<Editor>,
1607    ) -> (f32, Vec<BlockLayout>) {
1608        let mut block_id = 0;
1609        let scroll_x = snapshot.scroll_anchor.offset.x();
1610        let (fixed_blocks, non_fixed_blocks) = snapshot
1611            .blocks_in_range(rows.clone())
1612            .partition::<Vec<_>, _>(|(_, block)| match block {
1613                TransformBlock::ExcerptHeader { .. } => false,
1614                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
1615            });
1616        let mut render_block = |block: &TransformBlock, width: f32, block_id: usize| {
1617            let mut element = match block {
1618                TransformBlock::Custom(block) => {
1619                    let align_to = block
1620                        .position()
1621                        .to_point(&snapshot.buffer_snapshot)
1622                        .to_display_point(snapshot);
1623                    let anchor_x = text_x
1624                        + if rows.contains(&align_to.row()) {
1625                            line_layouts[(align_to.row() - rows.start) as usize]
1626                                .line
1627                                .x_for_index(align_to.column() as usize)
1628                        } else {
1629                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache())
1630                                .x_for_index(align_to.column() as usize)
1631                        };
1632
1633                    block.render(&mut BlockContext {
1634                        view_context: cx,
1635                        anchor_x,
1636                        gutter_padding,
1637                        line_height,
1638                        scroll_x,
1639                        gutter_width,
1640                        em_width,
1641                        block_id,
1642                    })
1643                }
1644                TransformBlock::ExcerptHeader {
1645                    id,
1646                    buffer,
1647                    range,
1648                    starts_new_buffer,
1649                    ..
1650                } => {
1651                    let tooltip_style = theme::current(cx).tooltip.clone();
1652                    let include_root = editor
1653                        .project
1654                        .as_ref()
1655                        .map(|project| project.read(cx).visible_worktrees(cx).count() > 1)
1656                        .unwrap_or_default();
1657                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
1658                        let jump_path = ProjectPath {
1659                            worktree_id: file.worktree_id(cx),
1660                            path: file.path.clone(),
1661                        };
1662                        let jump_anchor = range
1663                            .primary
1664                            .as_ref()
1665                            .map_or(range.context.start, |primary| primary.start);
1666                        let jump_position = language::ToPoint::to_point(&jump_anchor, buffer);
1667
1668                        enum JumpIcon {}
1669                        MouseEventHandler::<JumpIcon, _>::new((*id).into(), cx, |state, _| {
1670                            let style = style.jump_icon.style_for(state);
1671                            Svg::new("icons/arrow_up_right_8.svg")
1672                                .with_color(style.color)
1673                                .constrained()
1674                                .with_width(style.icon_width)
1675                                .aligned()
1676                                .contained()
1677                                .with_style(style.container)
1678                                .constrained()
1679                                .with_width(style.button_width)
1680                                .with_height(style.button_width)
1681                        })
1682                        .with_cursor_style(CursorStyle::PointingHand)
1683                        .on_click(MouseButton::Left, move |_, editor, cx| {
1684                            if let Some(workspace) = editor
1685                                .workspace
1686                                .as_ref()
1687                                .and_then(|(workspace, _)| workspace.upgrade(cx))
1688                            {
1689                                workspace.update(cx, |workspace, cx| {
1690                                    Editor::jump(
1691                                        workspace,
1692                                        jump_path.clone(),
1693                                        jump_position,
1694                                        jump_anchor,
1695                                        cx,
1696                                    );
1697                                });
1698                            }
1699                        })
1700                        .with_tooltip::<JumpIcon>(
1701                            (*id).into(),
1702                            "Jump to Buffer".to_string(),
1703                            Some(Box::new(crate::OpenExcerpts)),
1704                            tooltip_style.clone(),
1705                            cx,
1706                        )
1707                        .aligned()
1708                        .flex_float()
1709                    });
1710
1711                    if *starts_new_buffer {
1712                        let editor_font_size = style.text.font_size;
1713                        let style = &style.diagnostic_path_header;
1714                        let font_size = (style.text_scale_factor * editor_font_size).round();
1715
1716                        let path = buffer.resolve_file_path(cx, include_root);
1717                        let mut filename = None;
1718                        let mut parent_path = None;
1719                        // Can't use .and_then() because `.file_name()` and `.parent()` return references :(
1720                        if let Some(path) = path {
1721                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1722                            parent_path =
1723                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1724                        }
1725
1726                        Flex::row()
1727                            .with_child(
1728                                Label::new(
1729                                    filename.unwrap_or_else(|| "untitled".to_string()),
1730                                    style.filename.text.clone().with_font_size(font_size),
1731                                )
1732                                .contained()
1733                                .with_style(style.filename.container)
1734                                .aligned(),
1735                            )
1736                            .with_children(parent_path.map(|path| {
1737                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1738                                    .contained()
1739                                    .with_style(style.path.container)
1740                                    .aligned()
1741                            }))
1742                            .with_children(jump_icon)
1743                            .contained()
1744                            .with_style(style.container)
1745                            .with_padding_left(gutter_padding)
1746                            .with_padding_right(gutter_padding)
1747                            .expanded()
1748                            .into_any_named("path header block")
1749                    } else {
1750                        let text_style = style.text.clone();
1751                        Flex::row()
1752                            .with_child(Label::new("", text_style))
1753                            .with_children(jump_icon)
1754                            .contained()
1755                            .with_padding_left(gutter_padding)
1756                            .with_padding_right(gutter_padding)
1757                            .expanded()
1758                            .into_any_named("collapsed context")
1759                    }
1760                }
1761            };
1762
1763            element.layout(
1764                SizeConstraint {
1765                    min: Vector2F::zero(),
1766                    max: vec2f(width, block.height() as f32 * line_height),
1767                },
1768                editor,
1769                cx,
1770            );
1771            element
1772        };
1773
1774        let mut fixed_block_max_width = 0f32;
1775        let mut blocks = Vec::new();
1776        for (row, block) in fixed_blocks {
1777            let element = render_block(block, f32::INFINITY, block_id);
1778            block_id += 1;
1779            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1780            blocks.push(BlockLayout {
1781                row,
1782                element,
1783                style: BlockStyle::Fixed,
1784            });
1785        }
1786        for (row, block) in non_fixed_blocks {
1787            let style = match block {
1788                TransformBlock::Custom(block) => block.style(),
1789                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1790            };
1791            let width = match style {
1792                BlockStyle::Sticky => editor_width,
1793                BlockStyle::Flex => editor_width
1794                    .max(fixed_block_max_width)
1795                    .max(gutter_width + scroll_width),
1796                BlockStyle::Fixed => unreachable!(),
1797            };
1798            let element = render_block(block, width, block_id);
1799            block_id += 1;
1800            blocks.push(BlockLayout {
1801                row,
1802                element,
1803                style,
1804            });
1805        }
1806        (
1807            scroll_width.max(fixed_block_max_width - gutter_width),
1808            blocks,
1809        )
1810    }
1811}
1812
1813struct HighlightedChunk<'a> {
1814    chunk: &'a str,
1815    style: Option<HighlightStyle>,
1816    is_tab: bool,
1817}
1818
1819#[derive(Debug)]
1820pub struct LineWithInvisibles {
1821    pub line: Line,
1822    invisibles: Vec<Invisible>,
1823}
1824
1825impl LineWithInvisibles {
1826    fn from_chunks<'a>(
1827        chunks: impl Iterator<Item = HighlightedChunk<'a>>,
1828        text_style: &TextStyle,
1829        text_layout_cache: &TextLayoutCache,
1830        font_cache: &Arc<FontCache>,
1831        max_line_len: usize,
1832        max_line_count: usize,
1833        line_number_layouts: &[Option<Line>],
1834        editor_mode: EditorMode,
1835    ) -> Vec<Self> {
1836        let mut layouts = Vec::with_capacity(max_line_count);
1837        let mut line = String::new();
1838        let mut invisibles = Vec::new();
1839        let mut styles = Vec::new();
1840        let mut non_whitespace_added = false;
1841        let mut row = 0;
1842        let mut line_exceeded_max_len = false;
1843        for highlighted_chunk in chunks.chain([HighlightedChunk {
1844            chunk: "\n",
1845            style: None,
1846            is_tab: false,
1847        }]) {
1848            for (ix, mut line_chunk) in highlighted_chunk.chunk.split('\n').enumerate() {
1849                if ix > 0 {
1850                    layouts.push(Self {
1851                        line: text_layout_cache.layout_str(&line, text_style.font_size, &styles),
1852                        invisibles: invisibles.drain(..).collect(),
1853                    });
1854
1855                    line.clear();
1856                    styles.clear();
1857                    row += 1;
1858                    line_exceeded_max_len = false;
1859                    non_whitespace_added = false;
1860                    if row == max_line_count {
1861                        return layouts;
1862                    }
1863                }
1864
1865                if !line_chunk.is_empty() && !line_exceeded_max_len {
1866                    let text_style = if let Some(style) = highlighted_chunk.style {
1867                        text_style
1868                            .clone()
1869                            .highlight(style, font_cache)
1870                            .map(Cow::Owned)
1871                            .unwrap_or_else(|_| Cow::Borrowed(text_style))
1872                    } else {
1873                        Cow::Borrowed(text_style)
1874                    };
1875
1876                    if line.len() + line_chunk.len() > max_line_len {
1877                        let mut chunk_len = max_line_len - line.len();
1878                        while !line_chunk.is_char_boundary(chunk_len) {
1879                            chunk_len -= 1;
1880                        }
1881                        line_chunk = &line_chunk[..chunk_len];
1882                        line_exceeded_max_len = true;
1883                    }
1884
1885                    styles.push((
1886                        line_chunk.len(),
1887                        RunStyle {
1888                            font_id: text_style.font_id,
1889                            color: text_style.color,
1890                            underline: text_style.underline,
1891                        },
1892                    ));
1893
1894                    if editor_mode == EditorMode::Full {
1895                        // Line wrap pads its contents with fake whitespaces,
1896                        // avoid printing them
1897                        let inside_wrapped_string = line_number_layouts
1898                            .get(row)
1899                            .and_then(|layout| layout.as_ref())
1900                            .is_none();
1901                        if highlighted_chunk.is_tab {
1902                            if non_whitespace_added || !inside_wrapped_string {
1903                                invisibles.push(Invisible::Tab {
1904                                    line_start_offset: line.len(),
1905                                });
1906                            }
1907                        } else {
1908                            invisibles.extend(
1909                                line_chunk
1910                                    .chars()
1911                                    .enumerate()
1912                                    .filter(|(_, line_char)| {
1913                                        let is_whitespace = line_char.is_whitespace();
1914                                        non_whitespace_added |= !is_whitespace;
1915                                        is_whitespace
1916                                            && (non_whitespace_added || !inside_wrapped_string)
1917                                    })
1918                                    .map(|(whitespace_index, _)| Invisible::Whitespace {
1919                                        line_offset: line.len() + whitespace_index,
1920                                    }),
1921                            )
1922                        }
1923                    }
1924
1925                    line.push_str(line_chunk);
1926                }
1927            }
1928        }
1929
1930        layouts
1931    }
1932
1933    fn draw(
1934        &self,
1935        layout: &LayoutState,
1936        row: u32,
1937        scroll_top: f32,
1938        scene: &mut SceneBuilder,
1939        content_origin: Vector2F,
1940        scroll_left: f32,
1941        visible_text_bounds: RectF,
1942        whitespace_setting: ShowWhitespaceSetting,
1943        selection_ranges: &[Range<DisplayPoint>],
1944        visible_bounds: RectF,
1945        cx: &mut ViewContext<Editor>,
1946    ) {
1947        let line_height = layout.position_map.line_height;
1948        let line_y = row as f32 * line_height - scroll_top;
1949
1950        self.line.paint(
1951            scene,
1952            content_origin + vec2f(-scroll_left, line_y),
1953            visible_text_bounds,
1954            line_height,
1955            cx,
1956        );
1957
1958        self.draw_invisibles(
1959            &selection_ranges,
1960            layout,
1961            content_origin,
1962            scroll_left,
1963            line_y,
1964            row,
1965            scene,
1966            visible_bounds,
1967            line_height,
1968            whitespace_setting,
1969            cx,
1970        );
1971    }
1972
1973    fn draw_invisibles(
1974        &self,
1975        selection_ranges: &[Range<DisplayPoint>],
1976        layout: &LayoutState,
1977        content_origin: Vector2F,
1978        scroll_left: f32,
1979        line_y: f32,
1980        row: u32,
1981        scene: &mut SceneBuilder,
1982        visible_bounds: RectF,
1983        line_height: f32,
1984        whitespace_setting: ShowWhitespaceSetting,
1985        cx: &mut ViewContext<Editor>,
1986    ) {
1987        let allowed_invisibles_regions = match whitespace_setting {
1988            ShowWhitespaceSetting::None => return,
1989            ShowWhitespaceSetting::Selection => Some(selection_ranges),
1990            ShowWhitespaceSetting::All => None,
1991        };
1992
1993        for invisible in &self.invisibles {
1994            let (&token_offset, invisible_symbol) = match invisible {
1995                Invisible::Tab { line_start_offset } => (line_start_offset, &layout.tab_invisible),
1996                Invisible::Whitespace { line_offset } => (line_offset, &layout.space_invisible),
1997            };
1998
1999            let x_offset = self.line.x_for_index(token_offset);
2000            let invisible_offset =
2001                (layout.position_map.em_width - invisible_symbol.width()).max(0.0) / 2.0;
2002            let origin = content_origin + vec2f(-scroll_left + x_offset + invisible_offset, line_y);
2003
2004            if let Some(allowed_regions) = allowed_invisibles_regions {
2005                let invisible_point = DisplayPoint::new(row, token_offset as u32);
2006                if !allowed_regions
2007                    .iter()
2008                    .any(|region| region.start <= invisible_point && invisible_point < region.end)
2009                {
2010                    continue;
2011                }
2012            }
2013            invisible_symbol.paint(scene, origin, visible_bounds, line_height, cx);
2014        }
2015    }
2016}
2017
2018#[derive(Debug, Clone, Copy, PartialEq, Eq)]
2019enum Invisible {
2020    Tab { line_start_offset: usize },
2021    Whitespace { line_offset: usize },
2022}
2023
2024impl Element<Editor> for EditorElement {
2025    type LayoutState = LayoutState;
2026    type PaintState = ();
2027
2028    fn layout(
2029        &mut self,
2030        constraint: SizeConstraint,
2031        editor: &mut Editor,
2032        cx: &mut LayoutContext<Editor>,
2033    ) -> (Vector2F, Self::LayoutState) {
2034        let mut size = constraint.max;
2035        if size.x().is_infinite() {
2036            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
2037        }
2038
2039        let snapshot = editor.snapshot(cx);
2040        let style = self.style.clone();
2041
2042        let line_height = (style.text.font_size * style.line_height_scalar).round();
2043
2044        let gutter_padding;
2045        let gutter_width;
2046        let gutter_margin;
2047        if snapshot.show_gutter {
2048            let em_width = style.text.em_width(cx.font_cache());
2049            gutter_padding = (em_width * style.gutter_padding_factor).round();
2050            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
2051            gutter_margin = -style.text.descent(cx.font_cache());
2052        } else {
2053            gutter_padding = 0.0;
2054            gutter_width = 0.0;
2055            gutter_margin = 0.0;
2056        };
2057
2058        let text_width = size.x() - gutter_width;
2059        let em_width = style.text.em_width(cx.font_cache());
2060        let em_advance = style.text.em_advance(cx.font_cache());
2061        let overscroll = vec2f(em_width, 0.);
2062        let snapshot = {
2063            editor.set_visible_line_count(size.y() / line_height, cx);
2064
2065            let editor_width = text_width - gutter_margin - overscroll.x() - em_width;
2066            let wrap_width = match editor.soft_wrap_mode(cx) {
2067                SoftWrap::None => (MAX_LINE_LEN / 2) as f32 * em_advance,
2068                SoftWrap::EditorWidth => editor_width,
2069                SoftWrap::Column(column) => editor_width.min(column as f32 * em_advance),
2070            };
2071
2072            if editor.set_wrap_width(Some(wrap_width), cx) {
2073                editor.snapshot(cx)
2074            } else {
2075                snapshot
2076            }
2077        };
2078
2079        let wrap_guides = editor
2080            .wrap_guides(cx)
2081            .iter()
2082            .map(|(guide, active)| (self.column_pixels(*guide, cx), *active))
2083            .collect();
2084
2085        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
2086        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
2087            size.set_y(
2088                scroll_height
2089                    .min(constraint.max_along(Axis::Vertical))
2090                    .max(constraint.min_along(Axis::Vertical))
2091                    .min(line_height * max_lines as f32),
2092            )
2093        } else if let EditorMode::SingleLine = snapshot.mode {
2094            size.set_y(
2095                line_height
2096                    .min(constraint.max_along(Axis::Vertical))
2097                    .max(constraint.min_along(Axis::Vertical)),
2098            )
2099        } else if size.y().is_infinite() {
2100            size.set_y(scroll_height);
2101        }
2102        let gutter_size = vec2f(gutter_width, size.y());
2103        let text_size = vec2f(text_width, size.y());
2104
2105        let autoscroll_horizontally = editor.autoscroll_vertically(size.y(), line_height, cx);
2106        let mut snapshot = editor.snapshot(cx);
2107
2108        let scroll_position = snapshot.scroll_position();
2109        // The scroll position is a fractional point, the whole number of which represents
2110        // the top of the window in terms of display rows.
2111        let start_row = scroll_position.y() as u32;
2112        let height_in_lines = size.y() / line_height;
2113        let max_row = snapshot.max_point().row();
2114
2115        // Add 1 to ensure selections bleed off screen
2116        let end_row = 1 + cmp::min(
2117            (scroll_position.y() + height_in_lines).ceil() as u32,
2118            max_row,
2119        );
2120
2121        let start_anchor = if start_row == 0 {
2122            Anchor::min()
2123        } else {
2124            snapshot
2125                .buffer_snapshot
2126                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
2127        };
2128        let end_anchor = if end_row > max_row {
2129            Anchor::max()
2130        } else {
2131            snapshot
2132                .buffer_snapshot
2133                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
2134        };
2135
2136        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
2137        let mut active_rows = BTreeMap::new();
2138        let mut fold_ranges = Vec::new();
2139        let is_singleton = editor.is_singleton(cx);
2140
2141        let highlighted_rows = editor.highlighted_rows();
2142        let theme = theme::current(cx);
2143        let highlighted_ranges = editor.background_highlights_in_range(
2144            start_anchor..end_anchor,
2145            &snapshot.display_snapshot,
2146            theme.as_ref(),
2147        );
2148
2149        fold_ranges.extend(
2150            snapshot
2151                .folds_in_range(start_anchor..end_anchor)
2152                .map(|anchor| {
2153                    let start = anchor.start.to_point(&snapshot.buffer_snapshot);
2154                    (
2155                        start.row,
2156                        start.to_display_point(&snapshot.display_snapshot)
2157                            ..anchor.end.to_display_point(&snapshot),
2158                    )
2159                }),
2160        );
2161
2162        let mut remote_selections = HashMap::default();
2163        for (replica_id, line_mode, cursor_shape, selection) in snapshot
2164            .buffer_snapshot
2165            .remote_selections_in_range(&(start_anchor..end_anchor))
2166        {
2167            // The local selections match the leader's selections.
2168            if Some(replica_id) == editor.leader_replica_id {
2169                continue;
2170            }
2171            remote_selections
2172                .entry(replica_id)
2173                .or_insert(Vec::new())
2174                .push(SelectionLayout::new(
2175                    selection,
2176                    line_mode,
2177                    cursor_shape,
2178                    &snapshot.display_snapshot,
2179                    false,
2180                ));
2181        }
2182        selections.extend(remote_selections);
2183
2184        if editor.show_local_selections {
2185            let mut local_selections = editor
2186                .selections
2187                .disjoint_in_range(start_anchor..end_anchor, cx);
2188            local_selections.extend(editor.selections.pending(cx));
2189            let newest = editor.selections.newest(cx);
2190            for selection in &local_selections {
2191                let is_empty = selection.start == selection.end;
2192                let selection_start = snapshot.prev_line_boundary(selection.start).1;
2193                let mut selection_end = snapshot.next_line_boundary(selection.end).1;
2194
2195                // in vim visual mode the newline is considered at the end of the previous line
2196                // instead of at the start of the current line
2197                if editor.cursor_shape == CursorShape::Block
2198                    && !is_empty
2199                    && !selection.reversed
2200                    && selection.end.column == 0
2201                    && selection_end.row() > 0
2202                    && selection_end.row() < snapshot.max_buffer_row()
2203                {
2204                    selection_end = DisplayPoint::new(selection_end.row() - 1, 0);
2205                }
2206                for row in cmp::max(selection_start.row(), start_row)
2207                    ..=cmp::min(selection_end.row(), end_row)
2208                {
2209                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
2210                    *contains_non_empty_selection |= !is_empty;
2211                }
2212            }
2213
2214            // Render the local selections in the leader's color when following.
2215            let local_replica_id = editor
2216                .leader_replica_id
2217                .unwrap_or_else(|| editor.replica_id(cx));
2218
2219            selections.push((
2220                local_replica_id,
2221                local_selections
2222                    .into_iter()
2223                    .map(|selection| {
2224                        let is_newest = selection == newest;
2225                        SelectionLayout::new(
2226                            selection,
2227                            editor.selections.line_mode,
2228                            editor.cursor_shape,
2229                            &snapshot.display_snapshot,
2230                            is_newest,
2231                        )
2232                    })
2233                    .collect(),
2234            ));
2235        }
2236
2237        let scrollbar_settings = &settings::get::<EditorSettings>(cx).scrollbar;
2238        let show_scrollbars = match scrollbar_settings.show {
2239            ShowScrollbar::Auto => {
2240                // Git
2241                (is_singleton && scrollbar_settings.git_diff && snapshot.buffer_snapshot.has_git_diffs())
2242                ||
2243                // Selections
2244                (is_singleton && scrollbar_settings.selections && !highlighted_ranges.is_empty())
2245                // Scrollmanager
2246                || editor.scroll_manager.scrollbars_visible()
2247            }
2248            ShowScrollbar::System => editor.scroll_manager.scrollbars_visible(),
2249            ShowScrollbar::Always => true,
2250            ShowScrollbar::Never => false,
2251        };
2252
2253        let fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)> = fold_ranges
2254            .into_iter()
2255            .map(|(id, fold)| {
2256                let color = self
2257                    .style
2258                    .folds
2259                    .ellipses
2260                    .background
2261                    .style_for(&mut cx.mouse_state::<FoldMarkers>(id as usize))
2262                    .color;
2263
2264                (id, fold, color)
2265            })
2266            .collect();
2267
2268        let (line_number_layouts, fold_statuses) = self.layout_line_numbers(
2269            start_row..end_row,
2270            &active_rows,
2271            is_singleton,
2272            &snapshot,
2273            cx,
2274        );
2275
2276        let display_hunks = self.layout_git_gutters(start_row..end_row, &snapshot);
2277
2278        let scrollbar_row_range = scroll_position.y()..(scroll_position.y() + height_in_lines);
2279
2280        let mut max_visible_line_width = 0.0;
2281        let line_layouts =
2282            self.layout_lines(start_row..end_row, &line_number_layouts, &snapshot, cx);
2283        for line_with_invisibles in &line_layouts {
2284            if line_with_invisibles.line.width() > max_visible_line_width {
2285                max_visible_line_width = line_with_invisibles.line.width();
2286            }
2287        }
2288
2289        let style = self.style.clone();
2290        let longest_line_width = layout_line(
2291            snapshot.longest_row(),
2292            &snapshot,
2293            &style,
2294            cx.text_layout_cache(),
2295        )
2296        .width();
2297        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
2298        let em_width = style.text.em_width(cx.font_cache());
2299        let (scroll_width, blocks) = self.layout_blocks(
2300            start_row..end_row,
2301            &snapshot,
2302            size.x(),
2303            scroll_width,
2304            gutter_padding,
2305            gutter_width,
2306            em_width,
2307            gutter_width + gutter_margin,
2308            line_height,
2309            &style,
2310            &line_layouts,
2311            editor,
2312            cx,
2313        );
2314
2315        let scroll_max = vec2f(
2316            ((scroll_width - text_size.x()) / em_width).max(0.0),
2317            max_row as f32,
2318        );
2319
2320        let clamped = editor.scroll_manager.clamp_scroll_left(scroll_max.x());
2321
2322        let autoscrolled = if autoscroll_horizontally {
2323            editor.autoscroll_horizontally(
2324                start_row,
2325                text_size.x(),
2326                scroll_width,
2327                em_width,
2328                &line_layouts,
2329                cx,
2330            )
2331        } else {
2332            false
2333        };
2334
2335        if clamped || autoscrolled {
2336            snapshot = editor.snapshot(cx);
2337        }
2338
2339        let newest_selection_head = editor
2340            .selections
2341            .newest::<usize>(cx)
2342            .head()
2343            .to_display_point(&snapshot);
2344        let style = editor.style(cx);
2345
2346        let mut context_menu = None;
2347        let mut code_actions_indicator = None;
2348        if (start_row..end_row).contains(&newest_selection_head.row()) {
2349            if editor.context_menu_visible() {
2350                context_menu = editor.render_context_menu(newest_selection_head, style.clone(), cx);
2351            }
2352
2353            let active = matches!(
2354                editor.context_menu,
2355                Some(crate::ContextMenu::CodeActions(_))
2356            );
2357
2358            code_actions_indicator = editor
2359                .render_code_actions_indicator(&style, active, cx)
2360                .map(|indicator| (newest_selection_head.row(), indicator));
2361        }
2362
2363        let visible_rows = start_row..start_row + line_layouts.len() as u32;
2364        let mut hover = editor
2365            .hover_state
2366            .render(&snapshot, &style, visible_rows, cx);
2367        let mode = editor.mode;
2368
2369        let mut fold_indicators = editor.render_fold_indicators(
2370            fold_statuses,
2371            &style,
2372            editor.gutter_hovered,
2373            line_height,
2374            gutter_margin,
2375            cx,
2376        );
2377
2378        if let Some((_, context_menu)) = context_menu.as_mut() {
2379            context_menu.layout(
2380                SizeConstraint {
2381                    min: Vector2F::zero(),
2382                    max: vec2f(
2383                        cx.window_size().x() * 0.7,
2384                        (12. * line_height).min((size.y() - line_height) / 2.),
2385                    ),
2386                },
2387                editor,
2388                cx,
2389            );
2390        }
2391
2392        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
2393            indicator.layout(
2394                SizeConstraint::strict_along(
2395                    Axis::Vertical,
2396                    line_height * style.code_actions.vertical_scale,
2397                ),
2398                editor,
2399                cx,
2400            );
2401        }
2402
2403        for fold_indicator in fold_indicators.iter_mut() {
2404            if let Some(indicator) = fold_indicator.as_mut() {
2405                indicator.layout(
2406                    SizeConstraint::strict_along(
2407                        Axis::Vertical,
2408                        line_height * style.code_actions.vertical_scale,
2409                    ),
2410                    editor,
2411                    cx,
2412                );
2413            }
2414        }
2415
2416        if let Some((_, hover_popovers)) = hover.as_mut() {
2417            for hover_popover in hover_popovers.iter_mut() {
2418                hover_popover.layout(
2419                    SizeConstraint {
2420                        min: Vector2F::zero(),
2421                        max: vec2f(
2422                            (120. * em_width) // Default size
2423                                .min(size.x() / 2.) // Shrink to half of the editor width
2424                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
2425                            (16. * line_height) // Default size
2426                                .min(size.y() / 2.) // Shrink to half of the editor height
2427                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
2428                        ),
2429                    },
2430                    editor,
2431                    cx,
2432                );
2433            }
2434        }
2435
2436        let invisible_symbol_font_size = self.style.text.font_size / 2.0;
2437        let invisible_symbol_style = RunStyle {
2438            color: self.style.whitespace,
2439            font_id: self.style.text.font_id,
2440            underline: Default::default(),
2441        };
2442
2443        (
2444            size,
2445            LayoutState {
2446                mode,
2447                position_map: Arc::new(PositionMap {
2448                    size,
2449                    scroll_max,
2450                    line_layouts,
2451                    line_height,
2452                    em_width,
2453                    em_advance,
2454                    snapshot,
2455                }),
2456                visible_display_row_range: start_row..end_row,
2457                wrap_guides,
2458                gutter_size,
2459                gutter_padding,
2460                text_size,
2461                scrollbar_row_range,
2462                show_scrollbars,
2463                is_singleton,
2464                max_row,
2465                gutter_margin,
2466                active_rows,
2467                highlighted_rows,
2468                highlighted_ranges,
2469                fold_ranges,
2470                line_number_layouts,
2471                display_hunks,
2472                blocks,
2473                selections,
2474                context_menu,
2475                code_actions_indicator,
2476                fold_indicators,
2477                tab_invisible: cx.text_layout_cache().layout_str(
2478                    "",
2479                    invisible_symbol_font_size,
2480                    &[("".len(), invisible_symbol_style)],
2481                ),
2482                space_invisible: cx.text_layout_cache().layout_str(
2483                    "",
2484                    invisible_symbol_font_size,
2485                    &[("".len(), invisible_symbol_style)],
2486                ),
2487                hover_popovers: hover,
2488            },
2489        )
2490    }
2491
2492    fn paint(
2493        &mut self,
2494        scene: &mut SceneBuilder,
2495        bounds: RectF,
2496        visible_bounds: RectF,
2497        layout: &mut Self::LayoutState,
2498        editor: &mut Editor,
2499        cx: &mut ViewContext<Editor>,
2500    ) -> Self::PaintState {
2501        let visible_bounds = bounds.intersection(visible_bounds).unwrap_or_default();
2502        scene.push_layer(Some(visible_bounds));
2503
2504        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
2505        let text_bounds = RectF::new(
2506            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2507            layout.text_size,
2508        );
2509
2510        Self::attach_mouse_handlers(
2511            scene,
2512            &layout.position_map,
2513            layout.hover_popovers.is_some(),
2514            visible_bounds,
2515            text_bounds,
2516            gutter_bounds,
2517            bounds,
2518            cx,
2519        );
2520
2521        self.paint_background(scene, gutter_bounds, text_bounds, layout);
2522        if layout.gutter_size.x() > 0. {
2523            self.paint_gutter(scene, gutter_bounds, visible_bounds, layout, editor, cx);
2524        }
2525        self.paint_text(scene, text_bounds, visible_bounds, layout, editor, cx);
2526
2527        scene.push_layer(Some(bounds));
2528        if !layout.blocks.is_empty() {
2529            self.paint_blocks(scene, bounds, visible_bounds, layout, editor, cx);
2530        }
2531        self.paint_scrollbar(scene, bounds, layout, cx, &editor);
2532        scene.pop_layer();
2533
2534        scene.pop_layer();
2535    }
2536
2537    fn rect_for_text_range(
2538        &self,
2539        range_utf16: Range<usize>,
2540        bounds: RectF,
2541        _: RectF,
2542        layout: &Self::LayoutState,
2543        _: &Self::PaintState,
2544        _: &Editor,
2545        _: &ViewContext<Editor>,
2546    ) -> Option<RectF> {
2547        let text_bounds = RectF::new(
2548            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
2549            layout.text_size,
2550        );
2551        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
2552        let scroll_position = layout.position_map.snapshot.scroll_position();
2553        let start_row = scroll_position.y() as u32;
2554        let scroll_top = scroll_position.y() * layout.position_map.line_height;
2555        let scroll_left = scroll_position.x() * layout.position_map.em_width;
2556
2557        let range_start = OffsetUtf16(range_utf16.start)
2558            .to_display_point(&layout.position_map.snapshot.display_snapshot);
2559        if range_start.row() < start_row {
2560            return None;
2561        }
2562
2563        let line = &layout
2564            .position_map
2565            .line_layouts
2566            .get((range_start.row() - start_row) as usize)?
2567            .line;
2568        let range_start_x = line.x_for_index(range_start.column() as usize);
2569        let range_start_y = range_start.row() as f32 * layout.position_map.line_height;
2570        Some(RectF::new(
2571            content_origin
2572                + vec2f(
2573                    range_start_x,
2574                    range_start_y + layout.position_map.line_height,
2575                )
2576                - vec2f(scroll_left, scroll_top),
2577            vec2f(
2578                layout.position_map.em_width,
2579                layout.position_map.line_height,
2580            ),
2581        ))
2582    }
2583
2584    fn debug(
2585        &self,
2586        bounds: RectF,
2587        _: &Self::LayoutState,
2588        _: &Self::PaintState,
2589        _: &Editor,
2590        _: &ViewContext<Editor>,
2591    ) -> json::Value {
2592        json!({
2593            "type": "BufferElement",
2594            "bounds": bounds.to_json()
2595        })
2596    }
2597}
2598
2599type BufferRow = u32;
2600
2601pub struct LayoutState {
2602    position_map: Arc<PositionMap>,
2603    gutter_size: Vector2F,
2604    gutter_padding: f32,
2605    gutter_margin: f32,
2606    text_size: Vector2F,
2607    mode: EditorMode,
2608    wrap_guides: SmallVec<[(f32, bool); 2]>,
2609    visible_display_row_range: Range<u32>,
2610    active_rows: BTreeMap<u32, bool>,
2611    highlighted_rows: Option<Range<u32>>,
2612    line_number_layouts: Vec<Option<text_layout::Line>>,
2613    display_hunks: Vec<DisplayDiffHunk>,
2614    blocks: Vec<BlockLayout>,
2615    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
2616    fold_ranges: Vec<(BufferRow, Range<DisplayPoint>, Color)>,
2617    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
2618    scrollbar_row_range: Range<f32>,
2619    show_scrollbars: bool,
2620    is_singleton: bool,
2621    max_row: u32,
2622    context_menu: Option<(DisplayPoint, AnyElement<Editor>)>,
2623    code_actions_indicator: Option<(u32, AnyElement<Editor>)>,
2624    hover_popovers: Option<(DisplayPoint, Vec<AnyElement<Editor>>)>,
2625    fold_indicators: Vec<Option<AnyElement<Editor>>>,
2626    tab_invisible: Line,
2627    space_invisible: Line,
2628}
2629
2630struct PositionMap {
2631    size: Vector2F,
2632    line_height: f32,
2633    scroll_max: Vector2F,
2634    em_width: f32,
2635    em_advance: f32,
2636    line_layouts: Vec<LineWithInvisibles>,
2637    snapshot: EditorSnapshot,
2638}
2639
2640impl PositionMap {
2641    /// Returns two display points:
2642    /// 1. The nearest *valid* position in the editor
2643    /// 2. An unclipped, potentially *invalid* position that maps directly to
2644    ///    the given pixel position.
2645    fn point_for_position(
2646        &self,
2647        text_bounds: RectF,
2648        position: Vector2F,
2649    ) -> (DisplayPoint, DisplayPoint) {
2650        let scroll_position = self.snapshot.scroll_position();
2651        let position = position - text_bounds.origin();
2652        let y = position.y().max(0.0).min(self.size.y());
2653        let x = position.x() + (scroll_position.x() * self.em_width);
2654        let row = (y / self.line_height + scroll_position.y()) as u32;
2655        let (column, x_overshoot) = if let Some(line) = self
2656            .line_layouts
2657            .get(row as usize - scroll_position.y() as usize)
2658            .map(|line_with_spaces| &line_with_spaces.line)
2659        {
2660            if let Some(ix) = line.index_for_x(x) {
2661                (ix as u32, 0.0)
2662            } else {
2663                (line.len() as u32, 0f32.max(x - line.width()))
2664            }
2665        } else {
2666            (0, x)
2667        };
2668
2669        let mut target_point = DisplayPoint::new(row, column);
2670        let point = self.snapshot.clip_point(target_point, Bias::Left);
2671        *target_point.column_mut() += (x_overshoot / self.em_advance) as u32;
2672
2673        (point, target_point)
2674    }
2675}
2676
2677struct BlockLayout {
2678    row: u32,
2679    element: AnyElement<Editor>,
2680    style: BlockStyle,
2681}
2682
2683fn layout_line(
2684    row: u32,
2685    snapshot: &EditorSnapshot,
2686    style: &EditorStyle,
2687    layout_cache: &TextLayoutCache,
2688) -> text_layout::Line {
2689    let mut line = snapshot.line(row);
2690
2691    if line.len() > MAX_LINE_LEN {
2692        let mut len = MAX_LINE_LEN;
2693        while !line.is_char_boundary(len) {
2694            len -= 1;
2695        }
2696
2697        line.truncate(len);
2698    }
2699
2700    layout_cache.layout_str(
2701        &line,
2702        style.text.font_size,
2703        &[(
2704            snapshot.line_len(row) as usize,
2705            RunStyle {
2706                font_id: style.text.font_id,
2707                color: Color::black(),
2708                underline: Default::default(),
2709            },
2710        )],
2711    )
2712}
2713
2714#[derive(Debug)]
2715pub struct Cursor {
2716    origin: Vector2F,
2717    block_width: f32,
2718    line_height: f32,
2719    color: Color,
2720    shape: CursorShape,
2721    block_text: Option<Line>,
2722}
2723
2724impl Cursor {
2725    pub fn new(
2726        origin: Vector2F,
2727        block_width: f32,
2728        line_height: f32,
2729        color: Color,
2730        shape: CursorShape,
2731        block_text: Option<Line>,
2732    ) -> Cursor {
2733        Cursor {
2734            origin,
2735            block_width,
2736            line_height,
2737            color,
2738            shape,
2739            block_text,
2740        }
2741    }
2742
2743    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
2744        RectF::new(
2745            self.origin + origin,
2746            vec2f(self.block_width, self.line_height),
2747        )
2748    }
2749
2750    pub fn paint(&self, scene: &mut SceneBuilder, origin: Vector2F, cx: &mut WindowContext) {
2751        let bounds = match self.shape {
2752            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
2753            CursorShape::Block | CursorShape::Hollow => RectF::new(
2754                self.origin + origin,
2755                vec2f(self.block_width, self.line_height),
2756            ),
2757            CursorShape::Underscore => RectF::new(
2758                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
2759                vec2f(self.block_width, 2.0),
2760            ),
2761        };
2762
2763        //Draw background or border quad
2764        if matches!(self.shape, CursorShape::Hollow) {
2765            scene.push_quad(Quad {
2766                bounds,
2767                background: None,
2768                border: Border::all(1., self.color),
2769                corner_radius: 0.,
2770            });
2771        } else {
2772            scene.push_quad(Quad {
2773                bounds,
2774                background: Some(self.color),
2775                border: Default::default(),
2776                corner_radius: 0.,
2777            });
2778        }
2779
2780        if let Some(block_text) = &self.block_text {
2781            block_text.paint(scene, self.origin + origin, bounds, self.line_height, cx);
2782        }
2783    }
2784
2785    pub fn shape(&self) -> CursorShape {
2786        self.shape
2787    }
2788}
2789
2790#[derive(Debug)]
2791pub struct HighlightedRange {
2792    pub start_y: f32,
2793    pub line_height: f32,
2794    pub lines: Vec<HighlightedRangeLine>,
2795    pub color: Color,
2796    pub corner_radius: f32,
2797}
2798
2799#[derive(Debug)]
2800pub struct HighlightedRangeLine {
2801    pub start_x: f32,
2802    pub end_x: f32,
2803}
2804
2805impl HighlightedRange {
2806    pub fn paint(&self, bounds: RectF, scene: &mut SceneBuilder) {
2807        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
2808            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
2809            self.paint_lines(
2810                self.start_y + self.line_height,
2811                &self.lines[1..],
2812                bounds,
2813                scene,
2814            );
2815        } else {
2816            self.paint_lines(self.start_y, &self.lines, bounds, scene);
2817        }
2818    }
2819
2820    fn paint_lines(
2821        &self,
2822        start_y: f32,
2823        lines: &[HighlightedRangeLine],
2824        bounds: RectF,
2825        scene: &mut SceneBuilder,
2826    ) {
2827        if lines.is_empty() {
2828            return;
2829        }
2830
2831        let mut path = PathBuilder::new();
2832        let first_line = lines.first().unwrap();
2833        let last_line = lines.last().unwrap();
2834
2835        let first_top_left = vec2f(first_line.start_x, start_y);
2836        let first_top_right = vec2f(first_line.end_x, start_y);
2837
2838        let curve_height = vec2f(0., self.corner_radius);
2839        let curve_width = |start_x: f32, end_x: f32| {
2840            let max = (end_x - start_x) / 2.;
2841            let width = if max < self.corner_radius {
2842                max
2843            } else {
2844                self.corner_radius
2845            };
2846
2847            vec2f(width, 0.)
2848        };
2849
2850        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
2851        path.reset(first_top_right - top_curve_width);
2852        path.curve_to(first_top_right + curve_height, first_top_right);
2853
2854        let mut iter = lines.iter().enumerate().peekable();
2855        while let Some((ix, line)) = iter.next() {
2856            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
2857
2858            if let Some((_, next_line)) = iter.peek() {
2859                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
2860
2861                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
2862                    Ordering::Equal => {
2863                        path.line_to(bottom_right);
2864                    }
2865                    Ordering::Less => {
2866                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
2867                        path.line_to(bottom_right - curve_height);
2868                        if self.corner_radius > 0. {
2869                            path.curve_to(bottom_right - curve_width, bottom_right);
2870                        }
2871                        path.line_to(next_top_right + curve_width);
2872                        if self.corner_radius > 0. {
2873                            path.curve_to(next_top_right + curve_height, next_top_right);
2874                        }
2875                    }
2876                    Ordering::Greater => {
2877                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
2878                        path.line_to(bottom_right - curve_height);
2879                        if self.corner_radius > 0. {
2880                            path.curve_to(bottom_right + curve_width, bottom_right);
2881                        }
2882                        path.line_to(next_top_right - curve_width);
2883                        if self.corner_radius > 0. {
2884                            path.curve_to(next_top_right + curve_height, next_top_right);
2885                        }
2886                    }
2887                }
2888            } else {
2889                let curve_width = curve_width(line.start_x, line.end_x);
2890                path.line_to(bottom_right - curve_height);
2891                if self.corner_radius > 0. {
2892                    path.curve_to(bottom_right - curve_width, bottom_right);
2893                }
2894
2895                let bottom_left = vec2f(line.start_x, bottom_right.y());
2896                path.line_to(bottom_left + curve_width);
2897                if self.corner_radius > 0. {
2898                    path.curve_to(bottom_left - curve_height, bottom_left);
2899                }
2900            }
2901        }
2902
2903        if first_line.start_x > last_line.start_x {
2904            let curve_width = curve_width(last_line.start_x, first_line.start_x);
2905            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
2906            path.line_to(second_top_left + curve_height);
2907            if self.corner_radius > 0. {
2908                path.curve_to(second_top_left + curve_width, second_top_left);
2909            }
2910            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
2911            path.line_to(first_bottom_left - curve_width);
2912            if self.corner_radius > 0. {
2913                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
2914            }
2915        }
2916
2917        path.line_to(first_top_left + curve_height);
2918        if self.corner_radius > 0. {
2919            path.curve_to(first_top_left + top_curve_width, first_top_left);
2920        }
2921        path.line_to(first_top_right - top_curve_width);
2922
2923        scene.push_path(path.build(self.color, Some(bounds)));
2924    }
2925}
2926
2927fn position_to_display_point(
2928    position: Vector2F,
2929    text_bounds: RectF,
2930    position_map: &PositionMap,
2931) -> Option<DisplayPoint> {
2932    if text_bounds.contains_point(position) {
2933        let (point, target_point) = position_map.point_for_position(text_bounds, position);
2934        if point == target_point {
2935            Some(point)
2936        } else {
2937            None
2938        }
2939    } else {
2940        None
2941    }
2942}
2943
2944fn range_to_bounds(
2945    range: &Range<DisplayPoint>,
2946    content_origin: Vector2F,
2947    scroll_left: f32,
2948    scroll_top: f32,
2949    visible_row_range: &Range<u32>,
2950    line_end_overshoot: f32,
2951    position_map: &PositionMap,
2952) -> impl Iterator<Item = RectF> {
2953    let mut bounds: SmallVec<[RectF; 1]> = SmallVec::new();
2954
2955    if range.start == range.end {
2956        return bounds.into_iter();
2957    }
2958
2959    let start_row = visible_row_range.start;
2960    let end_row = visible_row_range.end;
2961
2962    let row_range = if range.end.column() == 0 {
2963        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
2964    } else {
2965        cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
2966    };
2967
2968    let first_y =
2969        content_origin.y() + row_range.start as f32 * position_map.line_height - scroll_top;
2970
2971    for (idx, row) in row_range.enumerate() {
2972        let line_layout = &position_map.line_layouts[(row - start_row) as usize].line;
2973
2974        let start_x = if row == range.start.row() {
2975            content_origin.x() + line_layout.x_for_index(range.start.column() as usize)
2976                - scroll_left
2977        } else {
2978            content_origin.x() - scroll_left
2979        };
2980
2981        let end_x = if row == range.end.row() {
2982            content_origin.x() + line_layout.x_for_index(range.end.column() as usize) - scroll_left
2983        } else {
2984            content_origin.x() + line_layout.width() + line_end_overshoot - scroll_left
2985        };
2986
2987        bounds.push(RectF::from_points(
2988            vec2f(start_x, first_y + position_map.line_height * idx as f32),
2989            vec2f(end_x, first_y + position_map.line_height * (idx + 1) as f32),
2990        ))
2991    }
2992
2993    bounds.into_iter()
2994}
2995
2996pub fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
2997    delta.powf(1.5) / 100.0
2998}
2999
3000fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
3001    delta.powf(1.2) / 300.0
3002}
3003
3004#[cfg(test)]
3005mod tests {
3006    use super::*;
3007    use crate::{
3008        display_map::{BlockDisposition, BlockProperties},
3009        editor_tests::{init_test, update_test_language_settings},
3010        Editor, MultiBuffer,
3011    };
3012    use gpui::TestAppContext;
3013    use language::language_settings;
3014    use log::info;
3015    use std::{num::NonZeroU32, sync::Arc};
3016    use util::test::sample_text;
3017
3018    #[gpui::test]
3019    fn test_layout_line_numbers(cx: &mut TestAppContext) {
3020        init_test(cx, |_| {});
3021
3022        let (_, editor) = cx.add_window(|cx| {
3023            let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
3024            Editor::new(EditorMode::Full, buffer, None, None, cx)
3025        });
3026        let element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3027
3028        let layouts = editor.update(cx, |editor, cx| {
3029            let snapshot = editor.snapshot(cx);
3030            element
3031                .layout_line_numbers(0..6, &Default::default(), false, &snapshot, cx)
3032                .0
3033        });
3034        assert_eq!(layouts.len(), 6);
3035    }
3036
3037    #[gpui::test]
3038    fn test_layout_with_placeholder_text_and_blocks(cx: &mut TestAppContext) {
3039        init_test(cx, |_| {});
3040
3041        let (_, editor) = cx.add_window(|cx| {
3042            let buffer = MultiBuffer::build_simple("", cx);
3043            Editor::new(EditorMode::Full, buffer, None, None, cx)
3044        });
3045
3046        editor.update(cx, |editor, cx| {
3047            editor.set_placeholder_text("hello", cx);
3048            editor.insert_blocks(
3049                [BlockProperties {
3050                    style: BlockStyle::Fixed,
3051                    disposition: BlockDisposition::Above,
3052                    height: 3,
3053                    position: Anchor::min(),
3054                    render: Arc::new(|_| Empty::new().into_any()),
3055                }],
3056                None,
3057                cx,
3058            );
3059
3060            // Blur the editor so that it displays placeholder text.
3061            cx.blur();
3062        });
3063
3064        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3065        let (size, mut state) = editor.update(cx, |editor, cx| {
3066            let mut new_parents = Default::default();
3067            let mut notify_views_if_parents_change = Default::default();
3068            let mut layout_cx = LayoutContext::new(
3069                cx,
3070                &mut new_parents,
3071                &mut notify_views_if_parents_change,
3072                false,
3073            );
3074            element.layout(
3075                SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
3076                editor,
3077                &mut layout_cx,
3078            )
3079        });
3080
3081        assert_eq!(state.position_map.line_layouts.len(), 4);
3082        assert_eq!(
3083            state
3084                .line_number_layouts
3085                .iter()
3086                .map(Option::is_some)
3087                .collect::<Vec<_>>(),
3088            &[false, false, false, true]
3089        );
3090
3091        // Don't panic.
3092        let mut scene = SceneBuilder::new(1.0);
3093        let bounds = RectF::new(Default::default(), size);
3094        editor.update(cx, |editor, cx| {
3095            element.paint(&mut scene, bounds, bounds, &mut state, editor, cx);
3096        });
3097    }
3098
3099    #[gpui::test]
3100    fn test_all_invisibles_drawing(cx: &mut TestAppContext) {
3101        const TAB_SIZE: u32 = 4;
3102
3103        let input_text = "\t \t|\t| a b";
3104        let expected_invisibles = vec![
3105            Invisible::Tab {
3106                line_start_offset: 0,
3107            },
3108            Invisible::Whitespace {
3109                line_offset: TAB_SIZE as usize,
3110            },
3111            Invisible::Tab {
3112                line_start_offset: TAB_SIZE as usize + 1,
3113            },
3114            Invisible::Tab {
3115                line_start_offset: TAB_SIZE as usize * 2 + 1,
3116            },
3117            Invisible::Whitespace {
3118                line_offset: TAB_SIZE as usize * 3 + 1,
3119            },
3120            Invisible::Whitespace {
3121                line_offset: TAB_SIZE as usize * 3 + 3,
3122            },
3123        ];
3124        assert_eq!(
3125            expected_invisibles.len(),
3126            input_text
3127                .chars()
3128                .filter(|initial_char| initial_char.is_whitespace())
3129                .count(),
3130            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
3131        );
3132
3133        init_test(cx, |s| {
3134            s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3135            s.defaults.tab_size = NonZeroU32::new(TAB_SIZE);
3136        });
3137
3138        let actual_invisibles =
3139            collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, 500.0);
3140
3141        assert_eq!(expected_invisibles, actual_invisibles);
3142    }
3143
3144    #[gpui::test]
3145    fn test_invisibles_dont_appear_in_certain_editors(cx: &mut TestAppContext) {
3146        init_test(cx, |s| {
3147            s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3148            s.defaults.tab_size = NonZeroU32::new(4);
3149        });
3150
3151        for editor_mode_without_invisibles in [
3152            EditorMode::SingleLine,
3153            EditorMode::AutoHeight { max_lines: 100 },
3154        ] {
3155            let invisibles = collect_invisibles_from_new_editor(
3156                cx,
3157                editor_mode_without_invisibles,
3158                "\t\t\t| | a b",
3159                500.0,
3160            );
3161            assert!(invisibles.is_empty(),
3162                "For editor mode {editor_mode_without_invisibles:?} no invisibles was expected but got {invisibles:?}");
3163        }
3164    }
3165
3166    #[gpui::test]
3167    fn test_wrapped_invisibles_drawing(cx: &mut TestAppContext) {
3168        let tab_size = 4;
3169        let input_text = "a\tbcd   ".repeat(9);
3170        let repeated_invisibles = [
3171            Invisible::Tab {
3172                line_start_offset: 1,
3173            },
3174            Invisible::Whitespace {
3175                line_offset: tab_size as usize + 3,
3176            },
3177            Invisible::Whitespace {
3178                line_offset: tab_size as usize + 4,
3179            },
3180            Invisible::Whitespace {
3181                line_offset: tab_size as usize + 5,
3182            },
3183        ];
3184        let expected_invisibles = std::iter::once(repeated_invisibles)
3185            .cycle()
3186            .take(9)
3187            .flatten()
3188            .collect::<Vec<_>>();
3189        assert_eq!(
3190            expected_invisibles.len(),
3191            input_text
3192                .chars()
3193                .filter(|initial_char| initial_char.is_whitespace())
3194                .count(),
3195            "Hardcoded expected invisibles differ from the actual ones in '{input_text}'"
3196        );
3197        info!("Expected invisibles: {expected_invisibles:?}");
3198
3199        init_test(cx, |_| {});
3200
3201        // Put the same string with repeating whitespace pattern into editors of various size,
3202        // take deliberately small steps during resizing, to put all whitespace kinds near the wrap point.
3203        let resize_step = 10.0;
3204        let mut editor_width = 200.0;
3205        while editor_width <= 1000.0 {
3206            update_test_language_settings(cx, |s| {
3207                s.defaults.tab_size = NonZeroU32::new(tab_size);
3208                s.defaults.show_whitespaces = Some(ShowWhitespaceSetting::All);
3209                s.defaults.preferred_line_length = Some(editor_width as u32);
3210                s.defaults.soft_wrap = Some(language_settings::SoftWrap::PreferredLineLength);
3211            });
3212
3213            let actual_invisibles =
3214                collect_invisibles_from_new_editor(cx, EditorMode::Full, &input_text, editor_width);
3215
3216            // Whatever the editor size is, ensure it has the same invisible kinds in the same order
3217            // (no good guarantees about the offsets: wrapping could trigger padding and its tests should check the offsets).
3218            let mut i = 0;
3219            for (actual_index, actual_invisible) in actual_invisibles.iter().enumerate() {
3220                i = actual_index;
3221                match expected_invisibles.get(i) {
3222                    Some(expected_invisible) => match (expected_invisible, actual_invisible) {
3223                        (Invisible::Whitespace { .. }, Invisible::Whitespace { .. })
3224                        | (Invisible::Tab { .. }, Invisible::Tab { .. }) => {}
3225                        _ => {
3226                            panic!("At index {i}, expected invisible {expected_invisible:?} does not match actual {actual_invisible:?} by kind. Actual invisibles: {actual_invisibles:?}")
3227                        }
3228                    },
3229                    None => panic!("Unexpected extra invisible {actual_invisible:?} at index {i}"),
3230                }
3231            }
3232            let missing_expected_invisibles = &expected_invisibles[i + 1..];
3233            assert!(
3234                missing_expected_invisibles.is_empty(),
3235                "Missing expected invisibles after index {i}: {missing_expected_invisibles:?}"
3236            );
3237
3238            editor_width += resize_step;
3239        }
3240    }
3241
3242    fn collect_invisibles_from_new_editor(
3243        cx: &mut TestAppContext,
3244        editor_mode: EditorMode,
3245        input_text: &str,
3246        editor_width: f32,
3247    ) -> Vec<Invisible> {
3248        info!(
3249            "Creating editor with mode {editor_mode:?}, width {editor_width} and text '{input_text}'"
3250        );
3251        let (_, editor) = cx.add_window(|cx| {
3252            let buffer = MultiBuffer::build_simple(&input_text, cx);
3253            Editor::new(editor_mode, buffer, None, None, cx)
3254        });
3255
3256        let mut element = EditorElement::new(editor.read_with(cx, |editor, cx| editor.style(cx)));
3257        let (_, layout_state) = editor.update(cx, |editor, cx| {
3258            editor.set_soft_wrap_mode(language_settings::SoftWrap::EditorWidth, cx);
3259            editor.set_wrap_width(Some(editor_width), cx);
3260
3261            let mut new_parents = Default::default();
3262            let mut notify_views_if_parents_change = Default::default();
3263            let mut layout_cx = LayoutContext::new(
3264                cx,
3265                &mut new_parents,
3266                &mut notify_views_if_parents_change,
3267                false,
3268            );
3269            element.layout(
3270                SizeConstraint::new(vec2f(editor_width, 500.), vec2f(editor_width, 500.)),
3271                editor,
3272                &mut layout_cx,
3273            )
3274        });
3275
3276        layout_state
3277            .position_map
3278            .line_layouts
3279            .iter()
3280            .map(|line_with_invisibles| &line_with_invisibles.invisibles)
3281            .flatten()
3282            .cloned()
3283            .collect()
3284    }
3285}