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