element.rs

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