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