element.rs

   1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSnapshot, Scroll, Select, SelectPhase,
   4    SoftWrap, ToPoint, MAX_LINE_LEN,
   5};
   6use crate::{
   7    display_map::{BlockStyle, DisplaySnapshot, TransformBlock},
   8    hover_popover::HoverAt,
   9    link_go_to_definition::{
  10        CmdShiftChanged, GoToFetchedDefinition, GoToFetchedTypeDefinition, UpdateGoToDefinitionLink,
  11    },
  12    mouse_context_menu::DeployMouseContextMenu,
  13    EditorStyle,
  14};
  15use clock::ReplicaId;
  16use collections::{BTreeMap, HashMap};
  17use gpui::{
  18    color::Color,
  19    elements::*,
  20    fonts::{HighlightStyle, Underline},
  21    geometry::{
  22        rect::RectF,
  23        vector::{vec2f, Vector2F},
  24        PathBuilder,
  25    },
  26    json::{self, ToJson},
  27    platform::CursorStyle,
  28    text_layout::{self, Line, RunStyle, TextLayoutCache},
  29    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext,
  30    LayoutContext, ModifiersChangedEvent, MouseButton, MouseButtonEvent, MouseMovedEvent,
  31    MouseRegion, MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext,
  32    WeakViewHandle,
  33};
  34use json::json;
  35use language::{Bias, DiagnosticSeverity, OffsetUtf16, Selection};
  36use project::ProjectPath;
  37use settings::Settings;
  38use smallvec::SmallVec;
  39use std::{
  40    cmp::{self, Ordering},
  41    fmt::Write,
  42    iter,
  43    ops::Range,
  44    sync::Arc,
  45};
  46
  47const MIN_POPOVER_CHARACTER_WIDTH: f32 = 20.;
  48const MIN_POPOVER_LINE_HEIGHT: f32 = 4.;
  49const HOVER_POPOVER_GAP: f32 = 10.;
  50
  51struct SelectionLayout {
  52    head: DisplayPoint,
  53    range: Range<DisplayPoint>,
  54}
  55
  56impl SelectionLayout {
  57    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  58        selection: Selection<T>,
  59        line_mode: bool,
  60        map: &DisplaySnapshot,
  61    ) -> Self {
  62        if line_mode {
  63            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  64            let point_range = map.expand_to_line(selection.range());
  65            Self {
  66                head: selection.head().to_display_point(map),
  67                range: point_range.start.to_display_point(map)
  68                    ..point_range.end.to_display_point(map),
  69            }
  70        } else {
  71            let selection = selection.map(|p| p.to_display_point(map));
  72            Self {
  73                head: selection.head(),
  74                range: selection.range(),
  75            }
  76        }
  77    }
  78}
  79
  80#[derive(Clone)]
  81pub struct EditorElement {
  82    view: WeakViewHandle<Editor>,
  83    style: Arc<EditorStyle>,
  84    cursor_shape: CursorShape,
  85}
  86
  87impl EditorElement {
  88    pub fn new(
  89        view: WeakViewHandle<Editor>,
  90        style: EditorStyle,
  91        cursor_shape: CursorShape,
  92    ) -> Self {
  93        Self {
  94            view,
  95            style: Arc::new(style),
  96            cursor_shape,
  97        }
  98    }
  99
 100    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
 101        self.view.upgrade(cx).unwrap().read(cx)
 102    }
 103
 104    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
 105    where
 106        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
 107    {
 108        self.view.upgrade(cx).unwrap().update(cx, f)
 109    }
 110
 111    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
 112        self.update_view(cx, |view, cx| view.snapshot(cx))
 113    }
 114
 115    fn attach_mouse_handlers(
 116        view: &WeakViewHandle<Editor>,
 117        position_map: &Arc<PositionMap>,
 118        visible_bounds: RectF,
 119        text_bounds: RectF,
 120        gutter_bounds: RectF,
 121        bounds: RectF,
 122        cx: &mut PaintContext,
 123    ) {
 124        enum EditorElementMouseHandlers {}
 125        cx.scene.push_mouse_region(
 126            MouseRegion::new::<EditorElementMouseHandlers>(view.id(), view.id(), visible_bounds)
 127                .on_down(MouseButton::Left, {
 128                    let position_map = position_map.clone();
 129                    move |e, cx| {
 130                        if !Self::mouse_down(
 131                            e.platform_event,
 132                            position_map.as_ref(),
 133                            text_bounds,
 134                            gutter_bounds,
 135                            cx,
 136                        ) {
 137                            cx.propogate_event();
 138                        }
 139                    }
 140                })
 141                .on_down(MouseButton::Right, {
 142                    let position_map = position_map.clone();
 143                    move |e, cx| {
 144                        if !Self::mouse_right_down(
 145                            e.position,
 146                            position_map.as_ref(),
 147                            text_bounds,
 148                            cx,
 149                        ) {
 150                            cx.propogate_event();
 151                        }
 152                    }
 153                })
 154                .on_up(MouseButton::Left, {
 155                    let view = view.clone();
 156                    let position_map = position_map.clone();
 157                    move |e, cx| {
 158                        if !Self::mouse_up(
 159                            view.clone(),
 160                            e.position,
 161                            e.cmd,
 162                            e.shift,
 163                            position_map.as_ref(),
 164                            text_bounds,
 165                            cx,
 166                        ) {
 167                            cx.propogate_event()
 168                        }
 169                    }
 170                })
 171                .on_drag(MouseButton::Left, {
 172                    let view = view.clone();
 173                    let position_map = position_map.clone();
 174                    move |e, cx| {
 175                        if !Self::mouse_dragged(
 176                            view.clone(),
 177                            e.platform_event,
 178                            position_map.as_ref(),
 179                            text_bounds,
 180                            cx,
 181                        ) {
 182                            cx.propogate_event()
 183                        }
 184                    }
 185                })
 186                .on_move({
 187                    let position_map = position_map.clone();
 188                    move |e, cx| {
 189                        if !Self::mouse_moved(e.platform_event, &position_map, text_bounds, cx) {
 190                            cx.propogate_event()
 191                        }
 192                    }
 193                })
 194                .on_scroll({
 195                    let position_map = position_map.clone();
 196                    move |e, cx| {
 197                        if !Self::scroll(e.position, e.delta, e.precise, &position_map, bounds, cx)
 198                        {
 199                            cx.propogate_event()
 200                        }
 201                    }
 202                }),
 203        );
 204    }
 205
 206    fn mouse_down(
 207        MouseButtonEvent {
 208            position,
 209            ctrl,
 210            alt,
 211            shift,
 212            cmd,
 213            mut click_count,
 214            ..
 215        }: MouseButtonEvent,
 216        position_map: &PositionMap,
 217        text_bounds: RectF,
 218        gutter_bounds: RectF,
 219        cx: &mut EventContext,
 220    ) -> bool {
 221        if gutter_bounds.contains_point(position) {
 222            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 223        } else if !text_bounds.contains_point(position) {
 224            return false;
 225        }
 226
 227        let (position, target_position) = position_map.point_for_position(text_bounds, position);
 228
 229        if shift && alt {
 230            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 231                position,
 232                goal_column: target_position.column(),
 233            }));
 234        } else if shift && !ctrl && !alt && !cmd {
 235            cx.dispatch_action(Select(SelectPhase::Extend {
 236                position,
 237                click_count,
 238            }));
 239        } else {
 240            cx.dispatch_action(Select(SelectPhase::Begin {
 241                position,
 242                add: alt,
 243                click_count,
 244            }));
 245        }
 246
 247        true
 248    }
 249
 250    fn mouse_right_down(
 251        position: Vector2F,
 252        position_map: &PositionMap,
 253        text_bounds: RectF,
 254        cx: &mut EventContext,
 255    ) -> bool {
 256        if !text_bounds.contains_point(position) {
 257            return false;
 258        }
 259
 260        let (point, _) = position_map.point_for_position(text_bounds, position);
 261
 262        cx.dispatch_action(DeployMouseContextMenu { position, point });
 263        true
 264    }
 265
 266    fn mouse_up(
 267        view: WeakViewHandle<Editor>,
 268        position: Vector2F,
 269        cmd: bool,
 270        shift: bool,
 271        position_map: &PositionMap,
 272        text_bounds: RectF,
 273        cx: &mut EventContext,
 274    ) -> bool {
 275        let view = view.upgrade(cx.app).unwrap().read(cx.app);
 276        let end_selection = view.has_pending_selection();
 277        let pending_nonempty_selections = view.has_pending_nonempty_selection();
 278
 279        if end_selection {
 280            cx.dispatch_action(Select(SelectPhase::End));
 281        }
 282
 283        if !pending_nonempty_selections && cmd && text_bounds.contains_point(position) {
 284            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 285
 286            if point == target_point {
 287                if shift {
 288                    cx.dispatch_action(GoToFetchedTypeDefinition { point });
 289                } else {
 290                    cx.dispatch_action(GoToFetchedDefinition { point });
 291                }
 292
 293                return true;
 294            }
 295        }
 296
 297        end_selection
 298    }
 299
 300    fn mouse_dragged(
 301        view: WeakViewHandle<Editor>,
 302        MouseMovedEvent {
 303            cmd,
 304            shift,
 305            position,
 306            ..
 307        }: MouseMovedEvent,
 308        position_map: &PositionMap,
 309        text_bounds: RectF,
 310        cx: &mut EventContext,
 311    ) -> bool {
 312        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 313        // Don't trigger hover popover if mouse is hovering over context menu
 314        let point = if text_bounds.contains_point(position) {
 315            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 316            if point == target_point {
 317                Some(point)
 318            } else {
 319                None
 320            }
 321        } else {
 322            None
 323        };
 324
 325        cx.dispatch_action(UpdateGoToDefinitionLink {
 326            point,
 327            cmd_held: cmd,
 328            shift_held: shift,
 329        });
 330
 331        let view = view.upgrade(cx.app).unwrap().read(cx.app);
 332        if view.has_pending_selection() {
 333            let mut scroll_delta = Vector2F::zero();
 334
 335            let vertical_margin = position_map.line_height.min(text_bounds.height() / 3.0);
 336            let top = text_bounds.origin_y() + vertical_margin;
 337            let bottom = text_bounds.lower_left().y() - vertical_margin;
 338            if position.y() < top {
 339                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 340            }
 341            if position.y() > bottom {
 342                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 343            }
 344
 345            let horizontal_margin = position_map.line_height.min(text_bounds.width() / 3.0);
 346            let left = text_bounds.origin_x() + horizontal_margin;
 347            let right = text_bounds.upper_right().x() - horizontal_margin;
 348            if position.x() < left {
 349                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 350                    left - position.x(),
 351                ))
 352            }
 353            if position.x() > right {
 354                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 355                    position.x() - right,
 356                ))
 357            }
 358
 359            let (position, target_position) =
 360                position_map.point_for_position(text_bounds, position);
 361
 362            cx.dispatch_action(Select(SelectPhase::Update {
 363                position,
 364                goal_column: target_position.column(),
 365                scroll_position: (position_map.snapshot.scroll_position() + scroll_delta)
 366                    .clamp(Vector2F::zero(), position_map.scroll_max),
 367            }));
 368
 369            cx.dispatch_action(HoverAt { point });
 370            true
 371        } else {
 372            cx.dispatch_action(HoverAt { point });
 373            false
 374        }
 375    }
 376
 377    fn mouse_moved(
 378        MouseMovedEvent {
 379            cmd,
 380            shift,
 381            position,
 382            ..
 383        }: MouseMovedEvent,
 384        position_map: &PositionMap,
 385        text_bounds: RectF,
 386        cx: &mut EventContext,
 387    ) -> bool {
 388        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 389        // Don't trigger hover popover if mouse is hovering over context menu
 390        let point = if text_bounds.contains_point(position) {
 391            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 392            if point == target_point {
 393                Some(point)
 394            } else {
 395                None
 396            }
 397        } else {
 398            None
 399        };
 400
 401        cx.dispatch_action(UpdateGoToDefinitionLink {
 402            point,
 403            cmd_held: cmd,
 404            shift_held: shift,
 405        });
 406
 407        cx.dispatch_action(HoverAt { point });
 408        true
 409    }
 410
 411    fn modifiers_changed(&self, event: ModifiersChangedEvent, cx: &mut EventContext) -> bool {
 412        cx.dispatch_action(CmdShiftChanged {
 413            cmd_down: event.cmd,
 414            shift_down: event.shift,
 415        });
 416        false
 417    }
 418
 419    fn scroll(
 420        position: Vector2F,
 421        mut delta: Vector2F,
 422        precise: bool,
 423        position_map: &PositionMap,
 424        bounds: RectF,
 425        cx: &mut EventContext,
 426    ) -> bool {
 427        if !bounds.contains_point(position) {
 428            return false;
 429        }
 430
 431        let max_glyph_width = position_map.em_width;
 432        if !precise {
 433            delta *= vec2f(max_glyph_width, position_map.line_height);
 434        }
 435
 436        let scroll_position = position_map.snapshot.scroll_position();
 437        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 438        let y =
 439            (scroll_position.y() * position_map.line_height - delta.y()) / position_map.line_height;
 440        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), position_map.scroll_max);
 441
 442        cx.dispatch_action(Scroll(scroll_position));
 443
 444        true
 445    }
 446
 447    fn paint_background(
 448        &self,
 449        gutter_bounds: RectF,
 450        text_bounds: RectF,
 451        layout: &LayoutState,
 452        cx: &mut PaintContext,
 453    ) {
 454        let bounds = gutter_bounds.union_rect(text_bounds);
 455        let scroll_top =
 456            layout.position_map.snapshot.scroll_position().y() * layout.position_map.line_height;
 457        let editor = self.view(cx.app);
 458        cx.scene.push_quad(Quad {
 459            bounds: gutter_bounds,
 460            background: Some(self.style.gutter_background),
 461            border: Border::new(0., Color::transparent_black()),
 462            corner_radius: 0.,
 463        });
 464        cx.scene.push_quad(Quad {
 465            bounds: text_bounds,
 466            background: Some(self.style.background),
 467            border: Border::new(0., Color::transparent_black()),
 468            corner_radius: 0.,
 469        });
 470
 471        if let EditorMode::Full = editor.mode {
 472            let mut active_rows = layout.active_rows.iter().peekable();
 473            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 474                let mut end_row = *start_row;
 475                while active_rows.peek().map_or(false, |r| {
 476                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 477                }) {
 478                    active_rows.next().unwrap();
 479                    end_row += 1;
 480                }
 481
 482                if !contains_non_empty_selection {
 483                    let origin = vec2f(
 484                        bounds.origin_x(),
 485                        bounds.origin_y() + (layout.position_map.line_height * *start_row as f32)
 486                            - scroll_top,
 487                    );
 488                    let size = vec2f(
 489                        bounds.width(),
 490                        layout.position_map.line_height * (end_row - start_row + 1) as f32,
 491                    );
 492                    cx.scene.push_quad(Quad {
 493                        bounds: RectF::new(origin, size),
 494                        background: Some(self.style.active_line_background),
 495                        border: Border::default(),
 496                        corner_radius: 0.,
 497                    });
 498                }
 499            }
 500
 501            if let Some(highlighted_rows) = &layout.highlighted_rows {
 502                let origin = vec2f(
 503                    bounds.origin_x(),
 504                    bounds.origin_y()
 505                        + (layout.position_map.line_height * highlighted_rows.start as f32)
 506                        - scroll_top,
 507                );
 508                let size = vec2f(
 509                    bounds.width(),
 510                    layout.position_map.line_height * highlighted_rows.len() as f32,
 511                );
 512                cx.scene.push_quad(Quad {
 513                    bounds: RectF::new(origin, size),
 514                    background: Some(self.style.highlighted_line_background),
 515                    border: Border::default(),
 516                    corner_radius: 0.,
 517                });
 518            }
 519        }
 520    }
 521
 522    fn paint_gutter(
 523        &mut self,
 524        bounds: RectF,
 525        visible_bounds: RectF,
 526        layout: &mut LayoutState,
 527        cx: &mut PaintContext,
 528    ) {
 529        let scroll_top =
 530            layout.position_map.snapshot.scroll_position().y() * layout.position_map.line_height;
 531        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 532            if let Some(line) = line {
 533                let line_origin = bounds.origin()
 534                    + vec2f(
 535                        bounds.width() - line.width() - layout.gutter_padding,
 536                        ix as f32 * layout.position_map.line_height
 537                            - (scroll_top % layout.position_map.line_height),
 538                    );
 539                line.paint(
 540                    line_origin,
 541                    visible_bounds,
 542                    layout.position_map.line_height,
 543                    cx,
 544                );
 545            }
 546        }
 547
 548        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 549            let mut x = bounds.width() - layout.gutter_padding;
 550            let mut y = *row as f32 * layout.position_map.line_height - scroll_top;
 551            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 552            y += (layout.position_map.line_height - indicator.size().y()) / 2.;
 553            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 554        }
 555    }
 556
 557    fn paint_text(
 558        &mut self,
 559        bounds: RectF,
 560        visible_bounds: RectF,
 561        layout: &mut LayoutState,
 562        paint: &mut PaintState,
 563        cx: &mut PaintContext,
 564    ) {
 565        let view = self.view(cx.app);
 566        let style = &self.style;
 567        let local_replica_id = view.replica_id(cx);
 568        let scroll_position = layout.position_map.snapshot.scroll_position();
 569        let start_row = scroll_position.y() as u32;
 570        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 571        let end_row =
 572            ((scroll_top + bounds.height()) / layout.position_map.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 573        let max_glyph_width = layout.position_map.em_width;
 574        let scroll_left = scroll_position.x() * max_glyph_width;
 575        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 576
 577        cx.scene.push_layer(Some(bounds));
 578
 579        cx.scene.push_cursor_region(CursorRegion {
 580            bounds,
 581            style: if !view.link_go_to_definition_state.definitions.is_empty() {
 582                CursorStyle::PointingHand
 583            } else {
 584                CursorStyle::IBeam
 585            },
 586        });
 587
 588        for (range, color) in &layout.highlighted_ranges {
 589            self.paint_highlighted_range(
 590                range.clone(),
 591                start_row,
 592                end_row,
 593                *color,
 594                0.,
 595                0.15 * layout.position_map.line_height,
 596                layout,
 597                content_origin,
 598                scroll_top,
 599                scroll_left,
 600                bounds,
 601                cx,
 602            );
 603        }
 604
 605        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 606        for (replica_id, selections) in &layout.selections {
 607            let selection_style = style.replica_selection_style(*replica_id);
 608            let corner_radius = 0.15 * layout.position_map.line_height;
 609
 610            for selection in selections {
 611                self.paint_highlighted_range(
 612                    selection.range.clone(),
 613                    start_row,
 614                    end_row,
 615                    selection_style.selection,
 616                    corner_radius,
 617                    corner_radius * 2.,
 618                    layout,
 619                    content_origin,
 620                    scroll_top,
 621                    scroll_left,
 622                    bounds,
 623                    cx,
 624                );
 625
 626                if view.show_local_cursors() || *replica_id != local_replica_id {
 627                    let cursor_position = selection.head;
 628                    if (start_row..end_row).contains(&cursor_position.row()) {
 629                        let cursor_row_layout = &layout.position_map.line_layouts
 630                            [(cursor_position.row() - start_row) as usize];
 631                        let cursor_column = cursor_position.column() as usize;
 632
 633                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 634                        let mut block_width =
 635                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 636                        if block_width == 0.0 {
 637                            block_width = layout.position_map.em_width;
 638                        }
 639                        let block_text = if let CursorShape::Block = self.cursor_shape {
 640                            layout
 641                                .position_map
 642                                .snapshot
 643                                .chars_at(cursor_position)
 644                                .next()
 645                                .and_then(|character| {
 646                                    let font_id =
 647                                        cursor_row_layout.font_for_index(cursor_column)?;
 648                                    let text = character.to_string();
 649
 650                                    Some(cx.text_layout_cache.layout_str(
 651                                        &text,
 652                                        cursor_row_layout.font_size(),
 653                                        &[(
 654                                            text.len(),
 655                                            RunStyle {
 656                                                font_id,
 657                                                color: style.background,
 658                                                underline: Default::default(),
 659                                            },
 660                                        )],
 661                                    ))
 662                                })
 663                        } else {
 664                            None
 665                        };
 666
 667                        let x = cursor_character_x - scroll_left;
 668                        let y = cursor_position.row() as f32 * layout.position_map.line_height
 669                            - scroll_top;
 670                        cursors.push(Cursor {
 671                            color: selection_style.cursor,
 672                            block_width,
 673                            origin: vec2f(x, y),
 674                            line_height: layout.position_map.line_height,
 675                            shape: self.cursor_shape,
 676                            block_text,
 677                        });
 678                    }
 679                }
 680            }
 681        }
 682
 683        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 684            // Draw glyphs
 685            for (ix, line) in layout.position_map.line_layouts.iter().enumerate() {
 686                let row = start_row + ix as u32;
 687                line.paint(
 688                    content_origin
 689                        + vec2f(
 690                            -scroll_left,
 691                            row as f32 * layout.position_map.line_height - scroll_top,
 692                        ),
 693                    visible_text_bounds,
 694                    layout.position_map.line_height,
 695                    cx,
 696                );
 697            }
 698        }
 699
 700        cx.scene.push_layer(Some(bounds));
 701        for cursor in cursors {
 702            cursor.paint(content_origin, cx);
 703        }
 704        cx.scene.pop_layer();
 705
 706        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 707            cx.scene.push_stacking_context(None);
 708            let cursor_row_layout =
 709                &layout.position_map.line_layouts[(position.row() - start_row) as usize];
 710            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 711            let y = (position.row() + 1) as f32 * layout.position_map.line_height - scroll_top;
 712            let mut list_origin = content_origin + vec2f(x, y);
 713            let list_width = context_menu.size().x();
 714            let list_height = context_menu.size().y();
 715
 716            // Snap the right edge of the list to the right edge of the window if
 717            // its horizontal bounds overflow.
 718            if list_origin.x() + list_width > cx.window_size.x() {
 719                list_origin.set_x((cx.window_size.x() - list_width).max(0.));
 720            }
 721
 722            if list_origin.y() + list_height > bounds.max_y() {
 723                list_origin.set_y(list_origin.y() - layout.position_map.line_height - list_height);
 724            }
 725
 726            context_menu.paint(
 727                list_origin,
 728                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 729                cx,
 730            );
 731
 732            paint.context_menu_bounds = Some(RectF::new(list_origin, context_menu.size()));
 733
 734            cx.scene.pop_stacking_context();
 735        }
 736
 737        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
 738            cx.scene.push_stacking_context(None);
 739
 740            // This is safe because we check on layout whether the required row is available
 741            let hovered_row_layout =
 742                &layout.position_map.line_layouts[(position.row() - start_row) as usize];
 743
 744            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
 745            // height. This is the size we will use to decide whether to render popovers above or below
 746            // the hovered line.
 747            let first_size = hover_popovers[0].size();
 748            let height_to_reserve = first_size.y()
 749                + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.position_map.line_height;
 750
 751            // Compute Hovered Point
 752            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 753            let y = position.row() as f32 * layout.position_map.line_height - scroll_top;
 754            let hovered_point = content_origin + vec2f(x, y);
 755
 756            paint.hover_popover_bounds.clear();
 757
 758            if hovered_point.y() - height_to_reserve > 0.0 {
 759                // There is enough space above. Render popovers above the hovered point
 760                let mut current_y = hovered_point.y();
 761                for hover_popover in hover_popovers {
 762                    let size = hover_popover.size();
 763                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
 764
 765                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 766                    if x_out_of_bounds < 0.0 {
 767                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 768                    }
 769
 770                    hover_popover.paint(
 771                        popover_origin,
 772                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 773                        cx,
 774                    );
 775
 776                    paint.hover_popover_bounds.push(
 777                        RectF::new(popover_origin, hover_popover.size())
 778                            .dilate(Vector2F::new(0., 5.)),
 779                    );
 780
 781                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
 782                }
 783            } else {
 784                // There is not enough space above. Render popovers below the hovered point
 785                let mut current_y = hovered_point.y() + layout.position_map.line_height;
 786                for hover_popover in hover_popovers {
 787                    let size = hover_popover.size();
 788                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
 789
 790                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 791                    if x_out_of_bounds < 0.0 {
 792                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 793                    }
 794
 795                    hover_popover.paint(
 796                        popover_origin,
 797                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 798                        cx,
 799                    );
 800
 801                    paint.hover_popover_bounds.push(
 802                        RectF::new(popover_origin, hover_popover.size())
 803                            .dilate(Vector2F::new(0., 5.)),
 804                    );
 805
 806                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
 807                }
 808            }
 809
 810            cx.scene.pop_stacking_context();
 811        }
 812
 813        cx.scene.pop_layer();
 814    }
 815
 816    #[allow(clippy::too_many_arguments)]
 817    fn paint_highlighted_range(
 818        &self,
 819        range: Range<DisplayPoint>,
 820        start_row: u32,
 821        end_row: u32,
 822        color: Color,
 823        corner_radius: f32,
 824        line_end_overshoot: f32,
 825        layout: &LayoutState,
 826        content_origin: Vector2F,
 827        scroll_top: f32,
 828        scroll_left: f32,
 829        bounds: RectF,
 830        cx: &mut PaintContext,
 831    ) {
 832        if range.start != range.end {
 833            let row_range = if range.end.column() == 0 {
 834                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 835            } else {
 836                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 837            };
 838
 839            let highlighted_range = HighlightedRange {
 840                color,
 841                line_height: layout.position_map.line_height,
 842                corner_radius,
 843                start_y: content_origin.y()
 844                    + row_range.start as f32 * layout.position_map.line_height
 845                    - scroll_top,
 846                lines: row_range
 847                    .into_iter()
 848                    .map(|row| {
 849                        let line_layout =
 850                            &layout.position_map.line_layouts[(row - start_row) as usize];
 851                        HighlightedRangeLine {
 852                            start_x: if row == range.start.row() {
 853                                content_origin.x()
 854                                    + line_layout.x_for_index(range.start.column() as usize)
 855                                    - scroll_left
 856                            } else {
 857                                content_origin.x() - scroll_left
 858                            },
 859                            end_x: if row == range.end.row() {
 860                                content_origin.x()
 861                                    + line_layout.x_for_index(range.end.column() as usize)
 862                                    - scroll_left
 863                            } else {
 864                                content_origin.x() + line_layout.width() + line_end_overshoot
 865                                    - scroll_left
 866                            },
 867                        }
 868                    })
 869                    .collect(),
 870            };
 871
 872            highlighted_range.paint(bounds, cx.scene);
 873        }
 874    }
 875
 876    fn paint_blocks(
 877        &mut self,
 878        bounds: RectF,
 879        visible_bounds: RectF,
 880        layout: &mut LayoutState,
 881        cx: &mut PaintContext,
 882    ) {
 883        let scroll_position = layout.position_map.snapshot.scroll_position();
 884        let scroll_left = scroll_position.x() * layout.position_map.em_width;
 885        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 886
 887        for block in &mut layout.blocks {
 888            let mut origin = bounds.origin()
 889                + vec2f(
 890                    0.,
 891                    block.row as f32 * layout.position_map.line_height - scroll_top,
 892                );
 893            if !matches!(block.style, BlockStyle::Sticky) {
 894                origin += vec2f(-scroll_left, 0.);
 895            }
 896            block.element.paint(origin, visible_bounds, cx);
 897        }
 898    }
 899
 900    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 901        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 902        let style = &self.style;
 903
 904        cx.text_layout_cache
 905            .layout_str(
 906                "1".repeat(digit_count).as_str(),
 907                style.text.font_size,
 908                &[(
 909                    digit_count,
 910                    RunStyle {
 911                        font_id: style.text.font_id,
 912                        color: Color::black(),
 913                        underline: Default::default(),
 914                    },
 915                )],
 916            )
 917            .width()
 918    }
 919
 920    fn layout_line_numbers(
 921        &self,
 922        rows: Range<u32>,
 923        active_rows: &BTreeMap<u32, bool>,
 924        snapshot: &EditorSnapshot,
 925        cx: &LayoutContext,
 926    ) -> Vec<Option<text_layout::Line>> {
 927        let style = &self.style;
 928        let include_line_numbers = snapshot.mode == EditorMode::Full;
 929        let mut line_number_layouts = Vec::with_capacity(rows.len());
 930        let mut line_number = String::new();
 931        for (ix, row) in snapshot
 932            .buffer_rows(rows.start)
 933            .take((rows.end - rows.start) as usize)
 934            .enumerate()
 935        {
 936            let display_row = rows.start + ix as u32;
 937            let color = if active_rows.contains_key(&display_row) {
 938                style.line_number_active
 939            } else {
 940                style.line_number
 941            };
 942            if let Some(buffer_row) = row {
 943                if include_line_numbers {
 944                    line_number.clear();
 945                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 946                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 947                        &line_number,
 948                        style.text.font_size,
 949                        &[(
 950                            line_number.len(),
 951                            RunStyle {
 952                                font_id: style.text.font_id,
 953                                color,
 954                                underline: Default::default(),
 955                            },
 956                        )],
 957                    )));
 958                }
 959            } else {
 960                line_number_layouts.push(None);
 961            }
 962        }
 963
 964        line_number_layouts
 965    }
 966
 967    fn layout_lines(
 968        &mut self,
 969        rows: Range<u32>,
 970        snapshot: &EditorSnapshot,
 971        cx: &LayoutContext,
 972    ) -> Vec<text_layout::Line> {
 973        if rows.start >= rows.end {
 974            return Vec::new();
 975        }
 976
 977        // When the editor is empty and unfocused, then show the placeholder.
 978        if snapshot.is_empty() && !snapshot.is_focused() {
 979            let placeholder_style = self
 980                .style
 981                .placeholder_text
 982                .as_ref()
 983                .unwrap_or(&self.style.text);
 984            let placeholder_text = snapshot.placeholder_text();
 985            let placeholder_lines = placeholder_text
 986                .as_ref()
 987                .map_or("", AsRef::as_ref)
 988                .split('\n')
 989                .skip(rows.start as usize)
 990                .chain(iter::repeat(""))
 991                .take(rows.len());
 992            placeholder_lines
 993                .map(|line| {
 994                    cx.text_layout_cache.layout_str(
 995                        line,
 996                        placeholder_style.font_size,
 997                        &[(
 998                            line.len(),
 999                            RunStyle {
1000                                font_id: placeholder_style.font_id,
1001                                color: placeholder_style.color,
1002                                underline: Default::default(),
1003                            },
1004                        )],
1005                    )
1006                })
1007                .collect()
1008        } else {
1009            let style = &self.style;
1010            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
1011                let mut highlight_style = chunk
1012                    .syntax_highlight_id
1013                    .and_then(|id| id.style(&style.syntax));
1014
1015                if let Some(chunk_highlight) = chunk.highlight_style {
1016                    if let Some(highlight_style) = highlight_style.as_mut() {
1017                        highlight_style.highlight(chunk_highlight);
1018                    } else {
1019                        highlight_style = Some(chunk_highlight);
1020                    }
1021                }
1022
1023                let mut diagnostic_highlight = HighlightStyle::default();
1024
1025                if chunk.is_unnecessary {
1026                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
1027                }
1028
1029                if let Some(severity) = chunk.diagnostic_severity {
1030                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
1031                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
1032                        let diagnostic_style = super::diagnostic_style(severity, true, style);
1033                        diagnostic_highlight.underline = Some(Underline {
1034                            color: Some(diagnostic_style.message.text.color),
1035                            thickness: 1.0.into(),
1036                            squiggly: true,
1037                        });
1038                    }
1039                }
1040
1041                if let Some(highlight_style) = highlight_style.as_mut() {
1042                    highlight_style.highlight(diagnostic_highlight);
1043                } else {
1044                    highlight_style = Some(diagnostic_highlight);
1045                }
1046
1047                (chunk.text, highlight_style)
1048            });
1049            layout_highlighted_chunks(
1050                chunks,
1051                &style.text,
1052                cx.text_layout_cache,
1053                cx.font_cache,
1054                MAX_LINE_LEN,
1055                rows.len() as usize,
1056            )
1057        }
1058    }
1059
1060    #[allow(clippy::too_many_arguments)]
1061    fn layout_blocks(
1062        &mut self,
1063        rows: Range<u32>,
1064        snapshot: &EditorSnapshot,
1065        editor_width: f32,
1066        scroll_width: f32,
1067        gutter_padding: f32,
1068        gutter_width: f32,
1069        em_width: f32,
1070        text_x: f32,
1071        line_height: f32,
1072        style: &EditorStyle,
1073        line_layouts: &[text_layout::Line],
1074        cx: &mut LayoutContext,
1075    ) -> (f32, Vec<BlockLayout>) {
1076        let editor = if let Some(editor) = self.view.upgrade(cx) {
1077            editor
1078        } else {
1079            return Default::default();
1080        };
1081
1082        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
1083        let scroll_x = snapshot.scroll_position.x();
1084        let (fixed_blocks, non_fixed_blocks) = snapshot
1085            .blocks_in_range(rows.clone())
1086            .partition::<Vec<_>, _>(|(_, block)| match block {
1087                TransformBlock::ExcerptHeader { .. } => false,
1088                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
1089            });
1090        let mut render_block = |block: &TransformBlock, width: f32| {
1091            let mut element = match block {
1092                TransformBlock::Custom(block) => {
1093                    let align_to = block
1094                        .position()
1095                        .to_point(&snapshot.buffer_snapshot)
1096                        .to_display_point(snapshot);
1097                    let anchor_x = text_x
1098                        + if rows.contains(&align_to.row()) {
1099                            line_layouts[(align_to.row() - rows.start) as usize]
1100                                .x_for_index(align_to.column() as usize)
1101                        } else {
1102                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
1103                                .x_for_index(align_to.column() as usize)
1104                        };
1105
1106                    cx.render(&editor, |_, cx| {
1107                        block.render(&mut BlockContext {
1108                            cx,
1109                            anchor_x,
1110                            gutter_padding,
1111                            line_height,
1112                            scroll_x,
1113                            gutter_width,
1114                            em_width,
1115                        })
1116                    })
1117                }
1118                TransformBlock::ExcerptHeader {
1119                    key,
1120                    buffer,
1121                    range,
1122                    starts_new_buffer,
1123                    ..
1124                } => {
1125                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
1126                        let jump_position = range
1127                            .primary
1128                            .as_ref()
1129                            .map_or(range.context.start, |primary| primary.start);
1130                        let jump_action = crate::Jump {
1131                            path: ProjectPath {
1132                                worktree_id: file.worktree_id(cx),
1133                                path: file.path.clone(),
1134                            },
1135                            position: language::ToPoint::to_point(&jump_position, buffer),
1136                            anchor: jump_position,
1137                        };
1138
1139                        enum JumpIcon {}
1140                        cx.render(&editor, |_, cx| {
1141                            MouseEventHandler::<JumpIcon>::new(*key, cx, |state, _| {
1142                                let style = style.jump_icon.style_for(state, false);
1143                                Svg::new("icons/arrow_up_right_8.svg")
1144                                    .with_color(style.color)
1145                                    .constrained()
1146                                    .with_width(style.icon_width)
1147                                    .aligned()
1148                                    .contained()
1149                                    .with_style(style.container)
1150                                    .constrained()
1151                                    .with_width(style.button_width)
1152                                    .with_height(style.button_width)
1153                                    .boxed()
1154                            })
1155                            .with_cursor_style(CursorStyle::PointingHand)
1156                            .on_click(MouseButton::Left, move |_, cx| {
1157                                cx.dispatch_action(jump_action.clone())
1158                            })
1159                            .with_tooltip::<JumpIcon, _>(
1160                                *key,
1161                                "Jump to Buffer".to_string(),
1162                                Some(Box::new(crate::OpenExcerpts)),
1163                                tooltip_style.clone(),
1164                                cx,
1165                            )
1166                            .aligned()
1167                            .flex_float()
1168                            .boxed()
1169                        })
1170                    });
1171
1172                    if *starts_new_buffer {
1173                        let style = &self.style.diagnostic_path_header;
1174                        let font_size =
1175                            (style.text_scale_factor * self.style.text.font_size).round();
1176
1177                        let mut filename = None;
1178                        let mut parent_path = None;
1179                        if let Some(file) = buffer.file() {
1180                            let path = file.path();
1181                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1182                            parent_path =
1183                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1184                        }
1185
1186                        Flex::row()
1187                            .with_child(
1188                                Label::new(
1189                                    filename.unwrap_or_else(|| "untitled".to_string()),
1190                                    style.filename.text.clone().with_font_size(font_size),
1191                                )
1192                                .contained()
1193                                .with_style(style.filename.container)
1194                                .aligned()
1195                                .boxed(),
1196                            )
1197                            .with_children(parent_path.map(|path| {
1198                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1199                                    .contained()
1200                                    .with_style(style.path.container)
1201                                    .aligned()
1202                                    .boxed()
1203                            }))
1204                            .with_children(jump_icon)
1205                            .contained()
1206                            .with_style(style.container)
1207                            .with_padding_left(gutter_padding)
1208                            .with_padding_right(gutter_padding)
1209                            .expanded()
1210                            .named("path header block")
1211                    } else {
1212                        let text_style = self.style.text.clone();
1213                        Flex::row()
1214                            .with_child(Label::new("".to_string(), text_style).boxed())
1215                            .with_children(jump_icon)
1216                            .contained()
1217                            .with_padding_left(gutter_padding)
1218                            .with_padding_right(gutter_padding)
1219                            .expanded()
1220                            .named("collapsed context")
1221                    }
1222                }
1223            };
1224
1225            element.layout(
1226                SizeConstraint {
1227                    min: Vector2F::zero(),
1228                    max: vec2f(width, block.height() as f32 * line_height),
1229                },
1230                cx,
1231            );
1232            element
1233        };
1234
1235        let mut fixed_block_max_width = 0f32;
1236        let mut blocks = Vec::new();
1237        for (row, block) in fixed_blocks {
1238            let element = render_block(block, f32::INFINITY);
1239            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1240            blocks.push(BlockLayout {
1241                row,
1242                element,
1243                style: BlockStyle::Fixed,
1244            });
1245        }
1246        for (row, block) in non_fixed_blocks {
1247            let style = match block {
1248                TransformBlock::Custom(block) => block.style(),
1249                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1250            };
1251            let width = match style {
1252                BlockStyle::Sticky => editor_width,
1253                BlockStyle::Flex => editor_width
1254                    .max(fixed_block_max_width)
1255                    .max(gutter_width + scroll_width),
1256                BlockStyle::Fixed => unreachable!(),
1257            };
1258            let element = render_block(block, width);
1259            blocks.push(BlockLayout {
1260                row,
1261                element,
1262                style,
1263            });
1264        }
1265        (
1266            scroll_width.max(fixed_block_max_width - gutter_width),
1267            blocks,
1268        )
1269    }
1270}
1271
1272impl Element for EditorElement {
1273    type LayoutState = LayoutState;
1274    type PaintState = PaintState;
1275
1276    fn layout(
1277        &mut self,
1278        constraint: SizeConstraint,
1279        cx: &mut LayoutContext,
1280    ) -> (Vector2F, Self::LayoutState) {
1281        let mut size = constraint.max;
1282        if size.x().is_infinite() {
1283            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1284        }
1285
1286        let snapshot = self.snapshot(cx.app);
1287        let style = self.style.clone();
1288        let line_height = style.text.line_height(cx.font_cache);
1289
1290        let gutter_padding;
1291        let gutter_width;
1292        let gutter_margin;
1293        if snapshot.mode == EditorMode::Full {
1294            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
1295            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1296            gutter_margin = -style.text.descent(cx.font_cache);
1297        } else {
1298            gutter_padding = 0.0;
1299            gutter_width = 0.0;
1300            gutter_margin = 0.0;
1301        };
1302
1303        let text_width = size.x() - gutter_width;
1304        let em_width = style.text.em_width(cx.font_cache);
1305        let em_advance = style.text.em_advance(cx.font_cache);
1306        let overscroll = vec2f(em_width, 0.);
1307        let snapshot = self.update_view(cx.app, |view, cx| {
1308            let wrap_width = match view.soft_wrap_mode(cx) {
1309                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
1310                SoftWrap::EditorWidth => {
1311                    Some(text_width - gutter_margin - overscroll.x() - em_width)
1312                }
1313                SoftWrap::Column(column) => Some(column as f32 * em_advance),
1314            };
1315
1316            if view.set_wrap_width(wrap_width, cx) {
1317                view.snapshot(cx)
1318            } else {
1319                snapshot
1320            }
1321        });
1322
1323        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1324        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1325            size.set_y(
1326                scroll_height
1327                    .min(constraint.max_along(Axis::Vertical))
1328                    .max(constraint.min_along(Axis::Vertical))
1329                    .min(line_height * max_lines as f32),
1330            )
1331        } else if let EditorMode::SingleLine = snapshot.mode {
1332            size.set_y(
1333                line_height
1334                    .min(constraint.max_along(Axis::Vertical))
1335                    .max(constraint.min_along(Axis::Vertical)),
1336            )
1337        } else if size.y().is_infinite() {
1338            size.set_y(scroll_height);
1339        }
1340        let gutter_size = vec2f(gutter_width, size.y());
1341        let text_size = vec2f(text_width, size.y());
1342
1343        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
1344            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
1345            let snapshot = view.snapshot(cx);
1346            (autoscroll_horizontally, snapshot)
1347        });
1348
1349        let scroll_position = snapshot.scroll_position();
1350        // The scroll position is a fractional point, the whole number of which represents
1351        // the top of the window in terms of display rows.
1352        let start_row = scroll_position.y() as u32;
1353        let scroll_top = scroll_position.y() * line_height;
1354
1355        // Add 1 to ensure selections bleed off screen
1356        let end_row = 1 + cmp::min(
1357            ((scroll_top + size.y()) / line_height).ceil() as u32,
1358            snapshot.max_point().row(),
1359        );
1360
1361        let start_anchor = if start_row == 0 {
1362            Anchor::min()
1363        } else {
1364            snapshot
1365                .buffer_snapshot
1366                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1367        };
1368        let end_anchor = if end_row > snapshot.max_point().row() {
1369            Anchor::max()
1370        } else {
1371            snapshot
1372                .buffer_snapshot
1373                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1374        };
1375
1376        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1377        let mut active_rows = BTreeMap::new();
1378        let mut highlighted_rows = None;
1379        let mut highlighted_ranges = Vec::new();
1380        self.update_view(cx.app, |view, cx| {
1381            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1382
1383            highlighted_rows = view.highlighted_rows();
1384            let theme = cx.global::<Settings>().theme.as_ref();
1385            highlighted_ranges = view.background_highlights_in_range(
1386                start_anchor.clone()..end_anchor.clone(),
1387                &display_map,
1388                theme,
1389            );
1390
1391            let mut remote_selections = HashMap::default();
1392            for (replica_id, line_mode, selection) in display_map
1393                .buffer_snapshot
1394                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1395            {
1396                // The local selections match the leader's selections.
1397                if Some(replica_id) == view.leader_replica_id {
1398                    continue;
1399                }
1400                remote_selections
1401                    .entry(replica_id)
1402                    .or_insert(Vec::new())
1403                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1404            }
1405            selections.extend(remote_selections);
1406
1407            if view.show_local_selections {
1408                let mut local_selections = view
1409                    .selections
1410                    .disjoint_in_range(start_anchor..end_anchor, cx);
1411                local_selections.extend(view.selections.pending(cx));
1412                for selection in &local_selections {
1413                    let is_empty = selection.start == selection.end;
1414                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1415                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1416                    for row in cmp::max(selection_start.row(), start_row)
1417                        ..=cmp::min(selection_end.row(), end_row)
1418                    {
1419                        let contains_non_empty_selection =
1420                            active_rows.entry(row).or_insert(!is_empty);
1421                        *contains_non_empty_selection |= !is_empty;
1422                    }
1423                }
1424
1425                // Render the local selections in the leader's color when following.
1426                let local_replica_id = view
1427                    .leader_replica_id
1428                    .unwrap_or_else(|| view.replica_id(cx));
1429
1430                selections.push((
1431                    local_replica_id,
1432                    local_selections
1433                        .into_iter()
1434                        .map(|selection| {
1435                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1436                        })
1437                        .collect(),
1438                ));
1439            }
1440        });
1441
1442        let line_number_layouts =
1443            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1444
1445        let mut max_visible_line_width = 0.0;
1446        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1447        for line in &line_layouts {
1448            if line.width() > max_visible_line_width {
1449                max_visible_line_width = line.width();
1450            }
1451        }
1452
1453        let style = self.style.clone();
1454        let longest_line_width = layout_line(
1455            snapshot.longest_row(),
1456            &snapshot,
1457            &style,
1458            cx.text_layout_cache,
1459        )
1460        .width();
1461        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1462        let em_width = style.text.em_width(cx.font_cache);
1463        let (scroll_width, blocks) = self.layout_blocks(
1464            start_row..end_row,
1465            &snapshot,
1466            size.x(),
1467            scroll_width,
1468            gutter_padding,
1469            gutter_width,
1470            em_width,
1471            gutter_width + gutter_margin,
1472            line_height,
1473            &style,
1474            &line_layouts,
1475            cx,
1476        );
1477
1478        let max_row = snapshot.max_point().row();
1479        let scroll_max = vec2f(
1480            ((scroll_width - text_size.x()) / em_width).max(0.0),
1481            max_row.saturating_sub(1) as f32,
1482        );
1483
1484        self.update_view(cx.app, |view, cx| {
1485            let clamped = view.clamp_scroll_left(scroll_max.x());
1486
1487            let autoscrolled = if autoscroll_horizontally {
1488                view.autoscroll_horizontally(
1489                    start_row,
1490                    text_size.x(),
1491                    scroll_width,
1492                    em_width,
1493                    &line_layouts,
1494                    cx,
1495                )
1496            } else {
1497                false
1498            };
1499
1500            if clamped || autoscrolled {
1501                snapshot = view.snapshot(cx);
1502            }
1503        });
1504
1505        let mut context_menu = None;
1506        let mut code_actions_indicator = None;
1507        let mut hover = None;
1508        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1509            let newest_selection_head = view
1510                .selections
1511                .newest::<usize>(cx)
1512                .head()
1513                .to_display_point(&snapshot);
1514
1515            let style = view.style(cx);
1516            if (start_row..end_row).contains(&newest_selection_head.row()) {
1517                if view.context_menu_visible() {
1518                    context_menu =
1519                        view.render_context_menu(newest_selection_head, style.clone(), cx);
1520                }
1521
1522                code_actions_indicator = view
1523                    .render_code_actions_indicator(&style, cx)
1524                    .map(|indicator| (newest_selection_head.row(), indicator));
1525            }
1526
1527            let visible_rows = start_row..start_row + line_layouts.len() as u32;
1528            hover = view.hover_state.render(&snapshot, &style, visible_rows, cx);
1529        });
1530
1531        if let Some((_, context_menu)) = context_menu.as_mut() {
1532            context_menu.layout(
1533                SizeConstraint {
1534                    min: Vector2F::zero(),
1535                    max: vec2f(
1536                        cx.window_size.x() * 0.7,
1537                        (12. * line_height).min((size.y() - line_height) / 2.),
1538                    ),
1539                },
1540                cx,
1541            );
1542        }
1543
1544        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1545            indicator.layout(
1546                SizeConstraint::strict_along(
1547                    Axis::Vertical,
1548                    line_height * style.code_actions.vertical_scale,
1549                ),
1550                cx,
1551            );
1552        }
1553
1554        if let Some((_, hover_popovers)) = hover.as_mut() {
1555            for hover_popover in hover_popovers.iter_mut() {
1556                hover_popover.layout(
1557                    SizeConstraint {
1558                        min: Vector2F::zero(),
1559                        max: vec2f(
1560                            (120. * em_width) // Default size
1561                                .min(size.x() / 2.) // Shrink to half of the editor width
1562                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
1563                            (16. * line_height) // Default size
1564                                .min(size.y() / 2.) // Shrink to half of the editor height
1565                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
1566                        ),
1567                    },
1568                    cx,
1569                );
1570            }
1571        }
1572
1573        (
1574            size,
1575            LayoutState {
1576                position_map: Arc::new(PositionMap {
1577                    size,
1578                    scroll_max,
1579                    line_layouts,
1580                    line_height,
1581                    em_width,
1582                    em_advance,
1583                    snapshot,
1584                }),
1585                gutter_size,
1586                gutter_padding,
1587                text_size,
1588                gutter_margin,
1589                active_rows,
1590                highlighted_rows,
1591                highlighted_ranges,
1592                line_number_layouts,
1593                blocks,
1594                selections,
1595                context_menu,
1596                code_actions_indicator,
1597                hover_popovers: hover,
1598            },
1599        )
1600    }
1601
1602    fn paint(
1603        &mut self,
1604        bounds: RectF,
1605        visible_bounds: RectF,
1606        layout: &mut Self::LayoutState,
1607        cx: &mut PaintContext,
1608    ) -> Self::PaintState {
1609        cx.scene.push_layer(Some(bounds));
1610
1611        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1612        let text_bounds = RectF::new(
1613            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1614            layout.text_size,
1615        );
1616
1617        let mut paint_state = PaintState {
1618            context_menu_bounds: None,
1619            hover_popover_bounds: Default::default(),
1620        };
1621
1622        Self::attach_mouse_handlers(
1623            &self.view,
1624            &layout.position_map,
1625            visible_bounds,
1626            text_bounds,
1627            gutter_bounds,
1628            bounds,
1629            cx,
1630        );
1631
1632        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1633        if layout.gutter_size.x() > 0. {
1634            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1635        }
1636        self.paint_text(text_bounds, visible_bounds, layout, &mut paint_state, cx);
1637
1638        if !layout.blocks.is_empty() {
1639            cx.scene.push_layer(Some(bounds));
1640            self.paint_blocks(bounds, visible_bounds, layout, cx);
1641            cx.scene.pop_layer();
1642        }
1643
1644        cx.scene.pop_layer();
1645
1646        paint_state
1647    }
1648
1649    fn dispatch_event(
1650        &mut self,
1651        event: &Event,
1652        _: RectF,
1653        _: RectF,
1654        _: &mut LayoutState,
1655        _: &mut PaintState,
1656        cx: &mut EventContext,
1657    ) -> bool {
1658        if let Event::ModifiersChanged(event) = event {
1659            self.modifiers_changed(*event, cx);
1660        }
1661
1662        false
1663    }
1664
1665    fn rect_for_text_range(
1666        &self,
1667        range_utf16: Range<usize>,
1668        bounds: RectF,
1669        _: RectF,
1670        layout: &Self::LayoutState,
1671        _: &Self::PaintState,
1672        _: &gpui::MeasurementContext,
1673    ) -> Option<RectF> {
1674        let text_bounds = RectF::new(
1675            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1676            layout.text_size,
1677        );
1678        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
1679        let scroll_position = layout.position_map.snapshot.scroll_position();
1680        let start_row = scroll_position.y() as u32;
1681        let scroll_top = scroll_position.y() * layout.position_map.line_height;
1682        let scroll_left = scroll_position.x() * layout.position_map.em_width;
1683
1684        let range_start = OffsetUtf16(range_utf16.start)
1685            .to_display_point(&layout.position_map.snapshot.display_snapshot);
1686        if range_start.row() < start_row {
1687            return None;
1688        }
1689
1690        let line = layout
1691            .position_map
1692            .line_layouts
1693            .get((range_start.row() - start_row) as usize)?;
1694        let range_start_x = line.x_for_index(range_start.column() as usize);
1695        let range_start_y = range_start.row() as f32 * layout.position_map.line_height;
1696        Some(RectF::new(
1697            content_origin
1698                + vec2f(
1699                    range_start_x,
1700                    range_start_y + layout.position_map.line_height,
1701                )
1702                - vec2f(scroll_left, scroll_top),
1703            vec2f(
1704                layout.position_map.em_width,
1705                layout.position_map.line_height,
1706            ),
1707        ))
1708    }
1709
1710    fn debug(
1711        &self,
1712        bounds: RectF,
1713        _: &Self::LayoutState,
1714        _: &Self::PaintState,
1715        _: &gpui::DebugContext,
1716    ) -> json::Value {
1717        json!({
1718            "type": "BufferElement",
1719            "bounds": bounds.to_json()
1720        })
1721    }
1722}
1723
1724pub struct LayoutState {
1725    position_map: Arc<PositionMap>,
1726    gutter_size: Vector2F,
1727    gutter_padding: f32,
1728    gutter_margin: f32,
1729    text_size: Vector2F,
1730    active_rows: BTreeMap<u32, bool>,
1731    highlighted_rows: Option<Range<u32>>,
1732    line_number_layouts: Vec<Option<text_layout::Line>>,
1733    blocks: Vec<BlockLayout>,
1734    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1735    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1736    context_menu: Option<(DisplayPoint, ElementBox)>,
1737    code_actions_indicator: Option<(u32, ElementBox)>,
1738    hover_popovers: Option<(DisplayPoint, Vec<ElementBox>)>,
1739}
1740
1741pub struct PositionMap {
1742    size: Vector2F,
1743    line_height: f32,
1744    scroll_max: Vector2F,
1745    em_width: f32,
1746    em_advance: f32,
1747    line_layouts: Vec<text_layout::Line>,
1748    snapshot: EditorSnapshot,
1749}
1750
1751impl PositionMap {
1752    /// Returns two display points:
1753    /// 1. The nearest *valid* position in the editor
1754    /// 2. An unclipped, potentially *invalid* position that maps directly to
1755    ///    the given pixel position.
1756    fn point_for_position(
1757        &self,
1758        text_bounds: RectF,
1759        position: Vector2F,
1760    ) -> (DisplayPoint, DisplayPoint) {
1761        let scroll_position = self.snapshot.scroll_position();
1762        let position = position - text_bounds.origin();
1763        let y = position.y().max(0.0).min(self.size.y());
1764        let x = position.x() + (scroll_position.x() * self.em_width);
1765        let row = (y / self.line_height + scroll_position.y()) as u32;
1766        let (column, x_overshoot) = if let Some(line) = self
1767            .line_layouts
1768            .get(row as usize - scroll_position.y() as usize)
1769        {
1770            if let Some(ix) = line.index_for_x(x) {
1771                (ix as u32, 0.0)
1772            } else {
1773                (line.len() as u32, 0f32.max(x - line.width()))
1774            }
1775        } else {
1776            (0, x)
1777        };
1778
1779        let mut target_point = DisplayPoint::new(row, column);
1780        let point = self.snapshot.clip_point(target_point, Bias::Left);
1781        *target_point.column_mut() += (x_overshoot / self.em_advance) as u32;
1782
1783        (point, target_point)
1784    }
1785}
1786
1787struct BlockLayout {
1788    row: u32,
1789    element: ElementBox,
1790    style: BlockStyle,
1791}
1792
1793fn layout_line(
1794    row: u32,
1795    snapshot: &EditorSnapshot,
1796    style: &EditorStyle,
1797    layout_cache: &TextLayoutCache,
1798) -> text_layout::Line {
1799    let mut line = snapshot.line(row);
1800
1801    if line.len() > MAX_LINE_LEN {
1802        let mut len = MAX_LINE_LEN;
1803        while !line.is_char_boundary(len) {
1804            len -= 1;
1805        }
1806
1807        line.truncate(len);
1808    }
1809
1810    layout_cache.layout_str(
1811        &line,
1812        style.text.font_size,
1813        &[(
1814            snapshot.line_len(row) as usize,
1815            RunStyle {
1816                font_id: style.text.font_id,
1817                color: Color::black(),
1818                underline: Default::default(),
1819            },
1820        )],
1821    )
1822}
1823
1824pub struct PaintState {
1825    context_menu_bounds: Option<RectF>,
1826    hover_popover_bounds: Vec<RectF>,
1827}
1828
1829#[derive(Copy, Clone, PartialEq, Eq, Debug)]
1830pub enum CursorShape {
1831    Bar,
1832    Block,
1833    Underscore,
1834    Hollow,
1835}
1836
1837impl Default for CursorShape {
1838    fn default() -> Self {
1839        CursorShape::Bar
1840    }
1841}
1842
1843#[derive(Debug)]
1844pub struct Cursor {
1845    origin: Vector2F,
1846    block_width: f32,
1847    line_height: f32,
1848    color: Color,
1849    shape: CursorShape,
1850    block_text: Option<Line>,
1851}
1852
1853impl Cursor {
1854    pub fn new(
1855        origin: Vector2F,
1856        block_width: f32,
1857        line_height: f32,
1858        color: Color,
1859        shape: CursorShape,
1860        block_text: Option<Line>,
1861    ) -> Cursor {
1862        Cursor {
1863            origin,
1864            block_width,
1865            line_height,
1866            color,
1867            shape,
1868            block_text,
1869        }
1870    }
1871
1872    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
1873        RectF::new(
1874            self.origin + origin,
1875            vec2f(self.block_width, self.line_height),
1876        )
1877    }
1878
1879    pub fn paint(&self, origin: Vector2F, cx: &mut PaintContext) {
1880        let bounds = match self.shape {
1881            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
1882            CursorShape::Block | CursorShape::Hollow => RectF::new(
1883                self.origin + origin,
1884                vec2f(self.block_width, self.line_height),
1885            ),
1886            CursorShape::Underscore => RectF::new(
1887                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
1888                vec2f(self.block_width, 2.0),
1889            ),
1890        };
1891
1892        //Draw background or border quad
1893        if matches!(self.shape, CursorShape::Hollow) {
1894            cx.scene.push_quad(Quad {
1895                bounds,
1896                background: None,
1897                border: Border::all(1., self.color),
1898                corner_radius: 0.,
1899            });
1900        } else {
1901            cx.scene.push_quad(Quad {
1902                bounds,
1903                background: Some(self.color),
1904                border: Default::default(),
1905                corner_radius: 0.,
1906            });
1907        }
1908
1909        if let Some(block_text) = &self.block_text {
1910            block_text.paint(self.origin + origin, bounds, self.line_height, cx);
1911        }
1912    }
1913
1914    pub fn shape(&self) -> CursorShape {
1915        self.shape
1916    }
1917}
1918
1919#[derive(Debug)]
1920pub struct HighlightedRange {
1921    pub start_y: f32,
1922    pub line_height: f32,
1923    pub lines: Vec<HighlightedRangeLine>,
1924    pub color: Color,
1925    pub corner_radius: f32,
1926}
1927
1928#[derive(Debug)]
1929pub struct HighlightedRangeLine {
1930    pub start_x: f32,
1931    pub end_x: f32,
1932}
1933
1934impl HighlightedRange {
1935    pub fn paint(&self, bounds: RectF, scene: &mut Scene) {
1936        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1937            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1938            self.paint_lines(
1939                self.start_y + self.line_height,
1940                &self.lines[1..],
1941                bounds,
1942                scene,
1943            );
1944        } else {
1945            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1946        }
1947    }
1948
1949    fn paint_lines(
1950        &self,
1951        start_y: f32,
1952        lines: &[HighlightedRangeLine],
1953        bounds: RectF,
1954        scene: &mut Scene,
1955    ) {
1956        if lines.is_empty() {
1957            return;
1958        }
1959
1960        let mut path = PathBuilder::new();
1961        let first_line = lines.first().unwrap();
1962        let last_line = lines.last().unwrap();
1963
1964        let first_top_left = vec2f(first_line.start_x, start_y);
1965        let first_top_right = vec2f(first_line.end_x, start_y);
1966
1967        let curve_height = vec2f(0., self.corner_radius);
1968        let curve_width = |start_x: f32, end_x: f32| {
1969            let max = (end_x - start_x) / 2.;
1970            let width = if max < self.corner_radius {
1971                max
1972            } else {
1973                self.corner_radius
1974            };
1975
1976            vec2f(width, 0.)
1977        };
1978
1979        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1980        path.reset(first_top_right - top_curve_width);
1981        path.curve_to(first_top_right + curve_height, first_top_right);
1982
1983        let mut iter = lines.iter().enumerate().peekable();
1984        while let Some((ix, line)) = iter.next() {
1985            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1986
1987            if let Some((_, next_line)) = iter.peek() {
1988                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1989
1990                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1991                    Ordering::Equal => {
1992                        path.line_to(bottom_right);
1993                    }
1994                    Ordering::Less => {
1995                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1996                        path.line_to(bottom_right - curve_height);
1997                        if self.corner_radius > 0. {
1998                            path.curve_to(bottom_right - curve_width, bottom_right);
1999                        }
2000                        path.line_to(next_top_right + curve_width);
2001                        if self.corner_radius > 0. {
2002                            path.curve_to(next_top_right + curve_height, next_top_right);
2003                        }
2004                    }
2005                    Ordering::Greater => {
2006                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
2007                        path.line_to(bottom_right - curve_height);
2008                        if self.corner_radius > 0. {
2009                            path.curve_to(bottom_right + curve_width, bottom_right);
2010                        }
2011                        path.line_to(next_top_right - curve_width);
2012                        if self.corner_radius > 0. {
2013                            path.curve_to(next_top_right + curve_height, next_top_right);
2014                        }
2015                    }
2016                }
2017            } else {
2018                let curve_width = curve_width(line.start_x, line.end_x);
2019                path.line_to(bottom_right - curve_height);
2020                if self.corner_radius > 0. {
2021                    path.curve_to(bottom_right - curve_width, bottom_right);
2022                }
2023
2024                let bottom_left = vec2f(line.start_x, bottom_right.y());
2025                path.line_to(bottom_left + curve_width);
2026                if self.corner_radius > 0. {
2027                    path.curve_to(bottom_left - curve_height, bottom_left);
2028                }
2029            }
2030        }
2031
2032        if first_line.start_x > last_line.start_x {
2033            let curve_width = curve_width(last_line.start_x, first_line.start_x);
2034            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
2035            path.line_to(second_top_left + curve_height);
2036            if self.corner_radius > 0. {
2037                path.curve_to(second_top_left + curve_width, second_top_left);
2038            }
2039            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
2040            path.line_to(first_bottom_left - curve_width);
2041            if self.corner_radius > 0. {
2042                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
2043            }
2044        }
2045
2046        path.line_to(first_top_left + curve_height);
2047        if self.corner_radius > 0. {
2048            path.curve_to(first_top_left + top_curve_width, first_top_left);
2049        }
2050        path.line_to(first_top_right - top_curve_width);
2051
2052        scene.push_path(path.build(self.color, Some(bounds)));
2053    }
2054}
2055
2056pub fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
2057    delta.powf(1.5) / 100.0
2058}
2059
2060fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
2061    delta.powf(1.2) / 300.0
2062}
2063
2064#[cfg(test)]
2065mod tests {
2066    use std::sync::Arc;
2067
2068    use super::*;
2069    use crate::{
2070        display_map::{BlockDisposition, BlockProperties},
2071        Editor, MultiBuffer,
2072    };
2073    use settings::Settings;
2074    use util::test::sample_text;
2075
2076    #[gpui::test]
2077    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
2078        cx.set_global(Settings::test(cx));
2079        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
2080        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
2081            Editor::new(EditorMode::Full, buffer, None, None, cx)
2082        });
2083        let element = EditorElement::new(
2084            editor.downgrade(),
2085            editor.read(cx).style(cx),
2086            CursorShape::Bar,
2087        );
2088
2089        let layouts = editor.update(cx, |editor, cx| {
2090            let snapshot = editor.snapshot(cx);
2091            let mut presenter = cx.build_presenter(window_id, 30.);
2092            let layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
2093            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &layout_cx)
2094        });
2095        assert_eq!(layouts.len(), 6);
2096    }
2097
2098    #[gpui::test]
2099    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
2100        cx.set_global(Settings::test(cx));
2101        let buffer = MultiBuffer::build_simple("", cx);
2102        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
2103            Editor::new(EditorMode::Full, buffer, None, None, cx)
2104        });
2105
2106        editor.update(cx, |editor, cx| {
2107            editor.set_placeholder_text("hello", cx);
2108            editor.insert_blocks(
2109                [BlockProperties {
2110                    style: BlockStyle::Fixed,
2111                    disposition: BlockDisposition::Above,
2112                    height: 3,
2113                    position: Anchor::min(),
2114                    render: Arc::new(|_| Empty::new().boxed()),
2115                }],
2116                cx,
2117            );
2118
2119            // Blur the editor so that it displays placeholder text.
2120            cx.blur();
2121        });
2122
2123        let mut element = EditorElement::new(
2124            editor.downgrade(),
2125            editor.read(cx).style(cx),
2126            CursorShape::Bar,
2127        );
2128
2129        let mut scene = Scene::new(1.0);
2130        let mut presenter = cx.build_presenter(window_id, 30.);
2131        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
2132        let (size, mut state) = element.layout(
2133            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
2134            &mut layout_cx,
2135        );
2136
2137        assert_eq!(state.position_map.line_layouts.len(), 4);
2138        assert_eq!(
2139            state
2140                .line_number_layouts
2141                .iter()
2142                .map(Option::is_some)
2143                .collect::<Vec<_>>(),
2144            &[false, false, false, true]
2145        );
2146
2147        // Don't panic.
2148        let bounds = RectF::new(Default::default(), size);
2149        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
2150        element.paint(bounds, bounds, &mut state, &mut paint_cx);
2151    }
2152}