element.rs

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