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