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::{
   9        HoverAt, HOVER_POPOVER_GAP, MIN_POPOVER_CHARACTER_WIDTH, MIN_POPOVER_LINE_HEIGHT,
  10    },
  11    link_go_to_definition::{
  12        CmdShiftChanged, GoToFetchedDefinition, GoToFetchedTypeDefinition, UpdateGoToDefinitionLink,
  13    },
  14    mouse_context_menu::DeployMouseContextMenu,
  15    EditorStyle,
  16};
  17use clock::ReplicaId;
  18use collections::{BTreeMap, HashMap};
  19use gpui::{
  20    color::Color,
  21    elements::*,
  22    fonts::{HighlightStyle, Underline},
  23    geometry::{
  24        rect::RectF,
  25        vector::{vec2f, Vector2F},
  26        PathBuilder,
  27    },
  28    json::{self, ToJson},
  29    platform::CursorStyle,
  30    text_layout::{self, Line, RunStyle, TextLayoutCache},
  31    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext,
  32    LayoutContext, ModifiersChangedEvent, MouseButton, MouseButtonEvent, MouseMovedEvent,
  33    MouseRegion, MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext,
  34    WeakViewHandle,
  35};
  36use json::json;
  37use language::git::{DiffHunk, DiffHunkStatus};
  38use language::{Bias, DiagnosticSeverity, OffsetUtf16, Selection};
  39use project::ProjectPath;
  40use settings::Settings;
  41use smallvec::SmallVec;
  42use std::{
  43    cmp::{self, Ordering},
  44    fmt::Write,
  45    iter,
  46    ops::Range,
  47    sync::Arc,
  48};
  49
  50struct SelectionLayout {
  51    head: DisplayPoint,
  52    range: Range<DisplayPoint>,
  53}
  54
  55impl SelectionLayout {
  56    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  57        selection: Selection<T>,
  58        line_mode: bool,
  59        map: &DisplaySnapshot,
  60    ) -> Self {
  61        if line_mode {
  62            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  63            let point_range = map.expand_to_line(selection.range());
  64            Self {
  65                head: selection.head().to_display_point(map),
  66                range: point_range.start.to_display_point(map)
  67                    ..point_range.end.to_display_point(map),
  68            }
  69        } else {
  70            let selection = selection.map(|p| p.to_display_point(map));
  71            Self {
  72                head: selection.head(),
  73                range: selection.range(),
  74            }
  75        }
  76    }
  77}
  78
  79#[derive(Clone)]
  80pub struct EditorElement {
  81    view: WeakViewHandle<Editor>,
  82    style: Arc<EditorStyle>,
  83    cursor_shape: CursorShape,
  84}
  85
  86impl EditorElement {
  87    pub fn new(
  88        view: WeakViewHandle<Editor>,
  89        style: EditorStyle,
  90        cursor_shape: CursorShape,
  91    ) -> Self {
  92        Self {
  93            view,
  94            style: Arc::new(style),
  95            cursor_shape,
  96        }
  97    }
  98
  99    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
 100        self.view.upgrade(cx).unwrap().read(cx)
 101    }
 102
 103    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
 104    where
 105        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
 106    {
 107        self.view.upgrade(cx).unwrap().update(cx, f)
 108    }
 109
 110    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
 111        self.update_view(cx, |view, cx| view.snapshot(cx))
 112    }
 113
 114    fn attach_mouse_handlers(
 115        view: &WeakViewHandle<Editor>,
 116        position_map: &Arc<PositionMap>,
 117        visible_bounds: RectF,
 118        text_bounds: RectF,
 119        gutter_bounds: RectF,
 120        bounds: RectF,
 121        cx: &mut PaintContext,
 122    ) {
 123        enum EditorElementMouseHandlers {}
 124        cx.scene.push_mouse_region(
 125            MouseRegion::new::<EditorElementMouseHandlers>(view.id(), view.id(), visible_bounds)
 126                .on_down(MouseButton::Left, {
 127                    let position_map = position_map.clone();
 128                    move |e, cx| {
 129                        if !Self::mouse_down(
 130                            e.platform_event,
 131                            position_map.as_ref(),
 132                            text_bounds,
 133                            gutter_bounds,
 134                            cx,
 135                        ) {
 136                            cx.propogate_event();
 137                        }
 138                    }
 139                })
 140                .on_down(MouseButton::Right, {
 141                    let position_map = position_map.clone();
 142                    move |e, cx| {
 143                        if !Self::mouse_right_down(
 144                            e.position,
 145                            position_map.as_ref(),
 146                            text_bounds,
 147                            cx,
 148                        ) {
 149                            cx.propogate_event();
 150                        }
 151                    }
 152                })
 153                .on_up(MouseButton::Left, {
 154                    let view = view.clone();
 155                    let position_map = position_map.clone();
 156                    move |e, cx| {
 157                        if !Self::mouse_up(
 158                            view.clone(),
 159                            e.position,
 160                            e.cmd,
 161                            e.shift,
 162                            position_map.as_ref(),
 163                            text_bounds,
 164                            cx,
 165                        ) {
 166                            cx.propogate_event()
 167                        }
 168                    }
 169                })
 170                .on_drag(MouseButton::Left, {
 171                    let view = view.clone();
 172                    let position_map = position_map.clone();
 173                    move |e, cx| {
 174                        if !Self::mouse_dragged(
 175                            view.clone(),
 176                            e.platform_event,
 177                            position_map.as_ref(),
 178                            text_bounds,
 179                            cx,
 180                        ) {
 181                            cx.propogate_event()
 182                        }
 183                    }
 184                })
 185                .on_move({
 186                    let position_map = position_map.clone();
 187                    move |e, cx| {
 188                        if !Self::mouse_moved(e.platform_event, &position_map, text_bounds, cx) {
 189                            cx.propogate_event()
 190                        }
 191                    }
 192                })
 193                .on_scroll({
 194                    let position_map = position_map.clone();
 195                    move |e, cx| {
 196                        if !Self::scroll(e.position, e.delta, e.precise, &position_map, bounds, cx)
 197                        {
 198                            cx.propogate_event()
 199                        }
 200                    }
 201                }),
 202        );
 203    }
 204
 205    fn mouse_down(
 206        MouseButtonEvent {
 207            position,
 208            ctrl,
 209            alt,
 210            shift,
 211            cmd,
 212            mut click_count,
 213            ..
 214        }: MouseButtonEvent,
 215        position_map: &PositionMap,
 216        text_bounds: RectF,
 217        gutter_bounds: RectF,
 218        cx: &mut EventContext,
 219    ) -> bool {
 220        if gutter_bounds.contains_point(position) {
 221            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 222        } else if !text_bounds.contains_point(position) {
 223            return false;
 224        }
 225
 226        let (position, target_position) = position_map.point_for_position(text_bounds, position);
 227
 228        if shift && alt {
 229            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 230                position,
 231                goal_column: target_position.column(),
 232            }));
 233        } else if shift && !ctrl && !alt && !cmd {
 234            cx.dispatch_action(Select(SelectPhase::Extend {
 235                position,
 236                click_count,
 237            }));
 238        } else {
 239            cx.dispatch_action(Select(SelectPhase::Begin {
 240                position,
 241                add: alt,
 242                click_count,
 243            }));
 244        }
 245
 246        true
 247    }
 248
 249    fn mouse_right_down(
 250        position: Vector2F,
 251        position_map: &PositionMap,
 252        text_bounds: RectF,
 253        cx: &mut EventContext,
 254    ) -> bool {
 255        if !text_bounds.contains_point(position) {
 256            return false;
 257        }
 258
 259        let (point, _) = position_map.point_for_position(text_bounds, position);
 260
 261        cx.dispatch_action(DeployMouseContextMenu { position, point });
 262        true
 263    }
 264
 265    fn mouse_up(
 266        view: WeakViewHandle<Editor>,
 267        position: Vector2F,
 268        cmd: bool,
 269        shift: bool,
 270        position_map: &PositionMap,
 271        text_bounds: RectF,
 272        cx: &mut EventContext,
 273    ) -> bool {
 274        let view = view.upgrade(cx.app).unwrap().read(cx.app);
 275        let end_selection = view.has_pending_selection();
 276        let pending_nonempty_selections = view.has_pending_nonempty_selection();
 277
 278        if end_selection {
 279            cx.dispatch_action(Select(SelectPhase::End));
 280        }
 281
 282        if !pending_nonempty_selections && cmd && text_bounds.contains_point(position) {
 283            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 284
 285            if point == target_point {
 286                if shift {
 287                    cx.dispatch_action(GoToFetchedTypeDefinition { point });
 288                } else {
 289                    cx.dispatch_action(GoToFetchedDefinition { point });
 290                }
 291
 292                return true;
 293            }
 294        }
 295
 296        end_selection
 297    }
 298
 299    fn mouse_dragged(
 300        view: WeakViewHandle<Editor>,
 301        MouseMovedEvent {
 302            cmd,
 303            shift,
 304            position,
 305            ..
 306        }: MouseMovedEvent,
 307        position_map: &PositionMap,
 308        text_bounds: RectF,
 309        cx: &mut EventContext,
 310    ) -> bool {
 311        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 312        // Don't trigger hover popover if mouse is hovering over context menu
 313        let point = if text_bounds.contains_point(position) {
 314            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 315            if point == target_point {
 316                Some(point)
 317            } else {
 318                None
 319            }
 320        } else {
 321            None
 322        };
 323
 324        cx.dispatch_action(UpdateGoToDefinitionLink {
 325            point,
 326            cmd_held: cmd,
 327            shift_held: shift,
 328        });
 329
 330        let view = view.upgrade(cx.app).unwrap().read(cx.app);
 331        if view.has_pending_selection() {
 332            let mut scroll_delta = Vector2F::zero();
 333
 334            let vertical_margin = position_map.line_height.min(text_bounds.height() / 3.0);
 335            let top = text_bounds.origin_y() + vertical_margin;
 336            let bottom = text_bounds.lower_left().y() - vertical_margin;
 337            if position.y() < top {
 338                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 339            }
 340            if position.y() > bottom {
 341                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 342            }
 343
 344            let horizontal_margin = position_map.line_height.min(text_bounds.width() / 3.0);
 345            let left = text_bounds.origin_x() + horizontal_margin;
 346            let right = text_bounds.upper_right().x() - horizontal_margin;
 347            if position.x() < left {
 348                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 349                    left - position.x(),
 350                ))
 351            }
 352            if position.x() > right {
 353                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 354                    position.x() - right,
 355                ))
 356            }
 357
 358            let (position, target_position) =
 359                position_map.point_for_position(text_bounds, position);
 360
 361            cx.dispatch_action(Select(SelectPhase::Update {
 362                position,
 363                goal_column: target_position.column(),
 364                scroll_position: (position_map.snapshot.scroll_position() + scroll_delta)
 365                    .clamp(Vector2F::zero(), position_map.scroll_max),
 366            }));
 367
 368            cx.dispatch_action(HoverAt { point });
 369            true
 370        } else {
 371            cx.dispatch_action(HoverAt { point });
 372            false
 373        }
 374    }
 375
 376    fn mouse_moved(
 377        MouseMovedEvent {
 378            cmd,
 379            shift,
 380            position,
 381            ..
 382        }: MouseMovedEvent,
 383        position_map: &PositionMap,
 384        text_bounds: RectF,
 385        cx: &mut EventContext,
 386    ) -> bool {
 387        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 388        // Don't trigger hover popover if mouse is hovering over context menu
 389        let point = if text_bounds.contains_point(position) {
 390            let (point, target_point) = position_map.point_for_position(text_bounds, position);
 391            if point == target_point {
 392                Some(point)
 393            } else {
 394                None
 395            }
 396        } else {
 397            None
 398        };
 399
 400        cx.dispatch_action(UpdateGoToDefinitionLink {
 401            point,
 402            cmd_held: cmd,
 403            shift_held: shift,
 404        });
 405
 406        cx.dispatch_action(HoverAt { point });
 407        true
 408    }
 409
 410    fn modifiers_changed(&self, event: ModifiersChangedEvent, cx: &mut EventContext) -> bool {
 411        cx.dispatch_action(CmdShiftChanged {
 412            cmd_down: event.cmd,
 413            shift_down: event.shift,
 414        });
 415        false
 416    }
 417
 418    fn scroll(
 419        position: Vector2F,
 420        mut delta: Vector2F,
 421        precise: bool,
 422        position_map: &PositionMap,
 423        bounds: RectF,
 424        cx: &mut EventContext,
 425    ) -> bool {
 426        if !bounds.contains_point(position) {
 427            return false;
 428        }
 429
 430        let max_glyph_width = position_map.em_width;
 431        if !precise {
 432            delta *= vec2f(max_glyph_width, position_map.line_height);
 433        }
 434
 435        let scroll_position = position_map.snapshot.scroll_position();
 436        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 437        let y =
 438            (scroll_position.y() * position_map.line_height - delta.y()) / position_map.line_height;
 439        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), position_map.scroll_max);
 440
 441        cx.dispatch_action(Scroll(scroll_position));
 442
 443        true
 444    }
 445
 446    fn paint_background(
 447        &self,
 448        gutter_bounds: RectF,
 449        text_bounds: RectF,
 450        layout: &LayoutState,
 451        cx: &mut PaintContext,
 452    ) {
 453        let bounds = gutter_bounds.union_rect(text_bounds);
 454        let scroll_top =
 455            layout.position_map.snapshot.scroll_position().y() * layout.position_map.line_height;
 456        let editor = self.view(cx.app);
 457        cx.scene.push_quad(Quad {
 458            bounds: gutter_bounds,
 459            background: Some(self.style.gutter_background),
 460            border: Border::new(0., Color::transparent_black()),
 461            corner_radius: 0.,
 462        });
 463        cx.scene.push_quad(Quad {
 464            bounds: text_bounds,
 465            background: Some(self.style.background),
 466            border: Border::new(0., Color::transparent_black()),
 467            corner_radius: 0.,
 468        });
 469
 470        if let EditorMode::Full = editor.mode {
 471            let mut active_rows = layout.active_rows.iter().peekable();
 472            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 473                let mut end_row = *start_row;
 474                while active_rows.peek().map_or(false, |r| {
 475                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 476                }) {
 477                    active_rows.next().unwrap();
 478                    end_row += 1;
 479                }
 480
 481                if !contains_non_empty_selection {
 482                    let origin = vec2f(
 483                        bounds.origin_x(),
 484                        bounds.origin_y() + (layout.position_map.line_height * *start_row as f32)
 485                            - scroll_top,
 486                    );
 487                    let size = vec2f(
 488                        bounds.width(),
 489                        layout.position_map.line_height * (end_row - start_row + 1) as f32,
 490                    );
 491                    cx.scene.push_quad(Quad {
 492                        bounds: RectF::new(origin, size),
 493                        background: Some(self.style.active_line_background),
 494                        border: Border::default(),
 495                        corner_radius: 0.,
 496                    });
 497                }
 498            }
 499
 500            if let Some(highlighted_rows) = &layout.highlighted_rows {
 501                let origin = vec2f(
 502                    bounds.origin_x(),
 503                    bounds.origin_y()
 504                        + (layout.position_map.line_height * highlighted_rows.start as f32)
 505                        - scroll_top,
 506                );
 507                let size = vec2f(
 508                    bounds.width(),
 509                    layout.position_map.line_height * highlighted_rows.len() as f32,
 510                );
 511                cx.scene.push_quad(Quad {
 512                    bounds: RectF::new(origin, size),
 513                    background: Some(self.style.highlighted_line_background),
 514                    border: Border::default(),
 515                    corner_radius: 0.,
 516                });
 517            }
 518        }
 519    }
 520
 521    fn paint_gutter(
 522        &mut self,
 523        bounds: RectF,
 524        visible_bounds: RectF,
 525        layout: &mut LayoutState,
 526        cx: &mut PaintContext,
 527    ) {
 528        let line_height = layout.position_map.line_height;
 529        let scroll_position = layout.position_map.snapshot.scroll_position();
 530        let scroll_top = scroll_position.y() * 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        for hunk in &layout.diff_hunks {
 549            let color = match hunk.status() {
 550                DiffHunkStatus::Added => Color::green(),
 551                DiffHunkStatus::Modified => Color::blue(),
 552
 553                //TODO: This rendering is entirely a horrible hack
 554                DiffHunkStatus::Removed => {
 555                    let row = hunk.buffer_range.start as i64 - 1;
 556
 557                    let offset = line_height / 2.;
 558                    let start_y = row as f32 * line_height + offset - scroll_top;
 559                    let end_y = start_y + line_height;
 560
 561                    let width = 0.4 * line_height;
 562                    let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 563                    let highlight_size = vec2f(width * 2., end_y - start_y);
 564                    let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 565
 566                    cx.scene.push_quad(Quad {
 567                        bounds: highlight_bounds,
 568                        background: Some(Color::red()),
 569                        border: Border::new(0., Color::transparent_black()),
 570                        corner_radius: 1. * line_height,
 571                    });
 572
 573                    continue;
 574                }
 575            };
 576
 577            let start_row = hunk.buffer_range.start;
 578            let end_row = hunk.buffer_range.end;
 579
 580            let start_y = start_row as f32 * line_height - scroll_top;
 581            let end_y = end_row as f32 * line_height - scroll_top;
 582
 583            let width = 0.22 * line_height;
 584            let highlight_origin = bounds.origin() + vec2f(-width, start_y);
 585            let highlight_size = vec2f(width * 2., end_y - start_y);
 586            let highlight_bounds = RectF::new(highlight_origin, highlight_size);
 587
 588            cx.scene.push_quad(Quad {
 589                bounds: highlight_bounds,
 590                background: Some(color),
 591                border: Border::new(0., Color::transparent_black()),
 592                corner_radius: 0.2 * line_height,
 593            });
 594        }
 595
 596        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 597            let mut x = bounds.width() - layout.gutter_padding;
 598            let mut y = *row as f32 * line_height - scroll_top;
 599            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 600            y += (line_height - indicator.size().y()) / 2.;
 601            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 602        }
 603    }
 604
 605    fn paint_text(
 606        &mut self,
 607        bounds: RectF,
 608        visible_bounds: RectF,
 609        layout: &mut LayoutState,
 610        cx: &mut PaintContext,
 611    ) {
 612        let view = self.view(cx.app);
 613        let style = &self.style;
 614        let local_replica_id = view.replica_id(cx);
 615        let scroll_position = layout.position_map.snapshot.scroll_position();
 616        let start_row = scroll_position.y() as u32;
 617        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 618        let end_row =
 619            ((scroll_top + bounds.height()) / layout.position_map.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 620        let max_glyph_width = layout.position_map.em_width;
 621        let scroll_left = scroll_position.x() * max_glyph_width;
 622        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 623
 624        cx.scene.push_layer(Some(bounds));
 625
 626        cx.scene.push_cursor_region(CursorRegion {
 627            bounds,
 628            style: if !view.link_go_to_definition_state.definitions.is_empty() {
 629                CursorStyle::PointingHand
 630            } else {
 631                CursorStyle::IBeam
 632            },
 633        });
 634
 635        for (range, color) in &layout.highlighted_ranges {
 636            self.paint_highlighted_range(
 637                range.clone(),
 638                start_row,
 639                end_row,
 640                *color,
 641                0.,
 642                0.15 * layout.position_map.line_height,
 643                layout,
 644                content_origin,
 645                scroll_top,
 646                scroll_left,
 647                bounds,
 648                cx,
 649            );
 650        }
 651
 652        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 653        for (replica_id, selections) in &layout.selections {
 654            let selection_style = style.replica_selection_style(*replica_id);
 655            let corner_radius = 0.15 * layout.position_map.line_height;
 656
 657            for selection in selections {
 658                self.paint_highlighted_range(
 659                    selection.range.clone(),
 660                    start_row,
 661                    end_row,
 662                    selection_style.selection,
 663                    corner_radius,
 664                    corner_radius * 2.,
 665                    layout,
 666                    content_origin,
 667                    scroll_top,
 668                    scroll_left,
 669                    bounds,
 670                    cx,
 671                );
 672
 673                if view.show_local_cursors() || *replica_id != local_replica_id {
 674                    let cursor_position = selection.head;
 675                    if (start_row..end_row).contains(&cursor_position.row()) {
 676                        let cursor_row_layout = &layout.position_map.line_layouts
 677                            [(cursor_position.row() - start_row) as usize];
 678                        let cursor_column = cursor_position.column() as usize;
 679
 680                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 681                        let mut block_width =
 682                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 683                        if block_width == 0.0 {
 684                            block_width = layout.position_map.em_width;
 685                        }
 686                        let block_text = if let CursorShape::Block = self.cursor_shape {
 687                            layout
 688                                .position_map
 689                                .snapshot
 690                                .chars_at(cursor_position)
 691                                .next()
 692                                .and_then(|character| {
 693                                    let font_id =
 694                                        cursor_row_layout.font_for_index(cursor_column)?;
 695                                    let text = character.to_string();
 696
 697                                    Some(cx.text_layout_cache.layout_str(
 698                                        &text,
 699                                        cursor_row_layout.font_size(),
 700                                        &[(
 701                                            text.len(),
 702                                            RunStyle {
 703                                                font_id,
 704                                                color: style.background,
 705                                                underline: Default::default(),
 706                                            },
 707                                        )],
 708                                    ))
 709                                })
 710                        } else {
 711                            None
 712                        };
 713
 714                        let x = cursor_character_x - scroll_left;
 715                        let y = cursor_position.row() as f32 * layout.position_map.line_height
 716                            - scroll_top;
 717                        cursors.push(Cursor {
 718                            color: selection_style.cursor,
 719                            block_width,
 720                            origin: vec2f(x, y),
 721                            line_height: layout.position_map.line_height,
 722                            shape: self.cursor_shape,
 723                            block_text,
 724                        });
 725                    }
 726                }
 727            }
 728        }
 729
 730        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 731            // Draw glyphs
 732            for (ix, line) in layout.position_map.line_layouts.iter().enumerate() {
 733                let row = start_row + ix as u32;
 734                line.paint(
 735                    content_origin
 736                        + vec2f(
 737                            -scroll_left,
 738                            row as f32 * layout.position_map.line_height - scroll_top,
 739                        ),
 740                    visible_text_bounds,
 741                    layout.position_map.line_height,
 742                    cx,
 743                );
 744            }
 745        }
 746
 747        cx.scene.push_layer(Some(bounds));
 748        for cursor in cursors {
 749            cursor.paint(content_origin, cx);
 750        }
 751        cx.scene.pop_layer();
 752
 753        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 754            cx.scene.push_stacking_context(None);
 755            let cursor_row_layout =
 756                &layout.position_map.line_layouts[(position.row() - start_row) as usize];
 757            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 758            let y = (position.row() + 1) as f32 * layout.position_map.line_height - scroll_top;
 759            let mut list_origin = content_origin + vec2f(x, y);
 760            let list_width = context_menu.size().x();
 761            let list_height = context_menu.size().y();
 762
 763            // Snap the right edge of the list to the right edge of the window if
 764            // its horizontal bounds overflow.
 765            if list_origin.x() + list_width > cx.window_size.x() {
 766                list_origin.set_x((cx.window_size.x() - list_width).max(0.));
 767            }
 768
 769            if list_origin.y() + list_height > bounds.max_y() {
 770                list_origin.set_y(list_origin.y() - layout.position_map.line_height - list_height);
 771            }
 772
 773            context_menu.paint(
 774                list_origin,
 775                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 776                cx,
 777            );
 778
 779            cx.scene.pop_stacking_context();
 780        }
 781
 782        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
 783            cx.scene.push_stacking_context(None);
 784
 785            // This is safe because we check on layout whether the required row is available
 786            let hovered_row_layout =
 787                &layout.position_map.line_layouts[(position.row() - start_row) as usize];
 788
 789            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
 790            // height. This is the size we will use to decide whether to render popovers above or below
 791            // the hovered line.
 792            let first_size = hover_popovers[0].size();
 793            let height_to_reserve = first_size.y()
 794                + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.position_map.line_height;
 795
 796            // Compute Hovered Point
 797            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 798            let y = position.row() as f32 * layout.position_map.line_height - scroll_top;
 799            let hovered_point = content_origin + vec2f(x, y);
 800
 801            if hovered_point.y() - height_to_reserve > 0.0 {
 802                // There is enough space above. Render popovers above the hovered point
 803                let mut current_y = hovered_point.y();
 804                for hover_popover in hover_popovers {
 805                    let size = hover_popover.size();
 806                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
 807
 808                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 809                    if x_out_of_bounds < 0.0 {
 810                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 811                    }
 812
 813                    hover_popover.paint(
 814                        popover_origin,
 815                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 816                        cx,
 817                    );
 818
 819                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
 820                }
 821            } else {
 822                // There is not enough space above. Render popovers below the hovered point
 823                let mut current_y = hovered_point.y() + layout.position_map.line_height;
 824                for hover_popover in hover_popovers {
 825                    let size = hover_popover.size();
 826                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
 827
 828                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 829                    if x_out_of_bounds < 0.0 {
 830                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 831                    }
 832
 833                    hover_popover.paint(
 834                        popover_origin,
 835                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 836                        cx,
 837                    );
 838
 839                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
 840                }
 841            }
 842
 843            cx.scene.pop_stacking_context();
 844        }
 845
 846        cx.scene.pop_layer();
 847    }
 848
 849    #[allow(clippy::too_many_arguments)]
 850    fn paint_highlighted_range(
 851        &self,
 852        range: Range<DisplayPoint>,
 853        start_row: u32,
 854        end_row: u32,
 855        color: Color,
 856        corner_radius: f32,
 857        line_end_overshoot: f32,
 858        layout: &LayoutState,
 859        content_origin: Vector2F,
 860        scroll_top: f32,
 861        scroll_left: f32,
 862        bounds: RectF,
 863        cx: &mut PaintContext,
 864    ) {
 865        if range.start != range.end {
 866            let row_range = if range.end.column() == 0 {
 867                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 868            } else {
 869                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 870            };
 871
 872            let highlighted_range = HighlightedRange {
 873                color,
 874                line_height: layout.position_map.line_height,
 875                corner_radius,
 876                start_y: content_origin.y()
 877                    + row_range.start as f32 * layout.position_map.line_height
 878                    - scroll_top,
 879                lines: row_range
 880                    .into_iter()
 881                    .map(|row| {
 882                        let line_layout =
 883                            &layout.position_map.line_layouts[(row - start_row) as usize];
 884                        HighlightedRangeLine {
 885                            start_x: if row == range.start.row() {
 886                                content_origin.x()
 887                                    + line_layout.x_for_index(range.start.column() as usize)
 888                                    - scroll_left
 889                            } else {
 890                                content_origin.x() - scroll_left
 891                            },
 892                            end_x: if row == range.end.row() {
 893                                content_origin.x()
 894                                    + line_layout.x_for_index(range.end.column() as usize)
 895                                    - scroll_left
 896                            } else {
 897                                content_origin.x() + line_layout.width() + line_end_overshoot
 898                                    - scroll_left
 899                            },
 900                        }
 901                    })
 902                    .collect(),
 903            };
 904
 905            highlighted_range.paint(bounds, cx.scene);
 906        }
 907    }
 908
 909    fn paint_blocks(
 910        &mut self,
 911        bounds: RectF,
 912        visible_bounds: RectF,
 913        layout: &mut LayoutState,
 914        cx: &mut PaintContext,
 915    ) {
 916        let scroll_position = layout.position_map.snapshot.scroll_position();
 917        let scroll_left = scroll_position.x() * layout.position_map.em_width;
 918        let scroll_top = scroll_position.y() * layout.position_map.line_height;
 919
 920        for block in &mut layout.blocks {
 921            let mut origin = bounds.origin()
 922                + vec2f(
 923                    0.,
 924                    block.row as f32 * layout.position_map.line_height - scroll_top,
 925                );
 926            if !matches!(block.style, BlockStyle::Sticky) {
 927                origin += vec2f(-scroll_left, 0.);
 928            }
 929            block.element.paint(origin, visible_bounds, cx);
 930        }
 931    }
 932
 933    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 934        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 935        let style = &self.style;
 936
 937        cx.text_layout_cache
 938            .layout_str(
 939                "1".repeat(digit_count).as_str(),
 940                style.text.font_size,
 941                &[(
 942                    digit_count,
 943                    RunStyle {
 944                        font_id: style.text.font_id,
 945                        color: Color::black(),
 946                        underline: Default::default(),
 947                    },
 948                )],
 949            )
 950            .width()
 951    }
 952
 953    fn layout_line_numbers(
 954        &self,
 955        rows: Range<u32>,
 956        active_rows: &BTreeMap<u32, bool>,
 957        snapshot: &EditorSnapshot,
 958        cx: &LayoutContext,
 959    ) -> Vec<Option<text_layout::Line>> {
 960        let style = &self.style;
 961        let include_line_numbers = snapshot.mode == EditorMode::Full;
 962        let mut line_number_layouts = Vec::with_capacity(rows.len());
 963        let mut line_number = String::new();
 964        for (ix, row) in snapshot
 965            .buffer_rows(rows.start)
 966            .take((rows.end - rows.start) as usize)
 967            .enumerate()
 968        {
 969            let display_row = rows.start + ix as u32;
 970            let color = if active_rows.contains_key(&display_row) {
 971                style.line_number_active
 972            } else {
 973                style.line_number
 974            };
 975            if let Some(buffer_row) = row {
 976                if include_line_numbers {
 977                    line_number.clear();
 978                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 979                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 980                        &line_number,
 981                        style.text.font_size,
 982                        &[(
 983                            line_number.len(),
 984                            RunStyle {
 985                                font_id: style.text.font_id,
 986                                color,
 987                                underline: Default::default(),
 988                            },
 989                        )],
 990                    )));
 991                }
 992            } else {
 993                line_number_layouts.push(None);
 994            }
 995        }
 996
 997        line_number_layouts
 998    }
 999
1000    fn layout_lines(
1001        &mut self,
1002        rows: Range<u32>,
1003        snapshot: &EditorSnapshot,
1004        cx: &LayoutContext,
1005    ) -> Vec<text_layout::Line> {
1006        if rows.start >= rows.end {
1007            return Vec::new();
1008        }
1009
1010        // When the editor is empty and unfocused, then show the placeholder.
1011        if snapshot.is_empty() && !snapshot.is_focused() {
1012            let placeholder_style = self
1013                .style
1014                .placeholder_text
1015                .as_ref()
1016                .unwrap_or(&self.style.text);
1017            let placeholder_text = snapshot.placeholder_text();
1018            let placeholder_lines = placeholder_text
1019                .as_ref()
1020                .map_or("", AsRef::as_ref)
1021                .split('\n')
1022                .skip(rows.start as usize)
1023                .chain(iter::repeat(""))
1024                .take(rows.len());
1025            placeholder_lines
1026                .map(|line| {
1027                    cx.text_layout_cache.layout_str(
1028                        line,
1029                        placeholder_style.font_size,
1030                        &[(
1031                            line.len(),
1032                            RunStyle {
1033                                font_id: placeholder_style.font_id,
1034                                color: placeholder_style.color,
1035                                underline: Default::default(),
1036                            },
1037                        )],
1038                    )
1039                })
1040                .collect()
1041        } else {
1042            let style = &self.style;
1043            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
1044                let mut highlight_style = chunk
1045                    .syntax_highlight_id
1046                    .and_then(|id| id.style(&style.syntax));
1047
1048                if let Some(chunk_highlight) = chunk.highlight_style {
1049                    if let Some(highlight_style) = highlight_style.as_mut() {
1050                        highlight_style.highlight(chunk_highlight);
1051                    } else {
1052                        highlight_style = Some(chunk_highlight);
1053                    }
1054                }
1055
1056                let mut diagnostic_highlight = HighlightStyle::default();
1057
1058                if chunk.is_unnecessary {
1059                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
1060                }
1061
1062                if let Some(severity) = chunk.diagnostic_severity {
1063                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
1064                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
1065                        let diagnostic_style = super::diagnostic_style(severity, true, style);
1066                        diagnostic_highlight.underline = Some(Underline {
1067                            color: Some(diagnostic_style.message.text.color),
1068                            thickness: 1.0.into(),
1069                            squiggly: true,
1070                        });
1071                    }
1072                }
1073
1074                if let Some(highlight_style) = highlight_style.as_mut() {
1075                    highlight_style.highlight(diagnostic_highlight);
1076                } else {
1077                    highlight_style = Some(diagnostic_highlight);
1078                }
1079
1080                (chunk.text, highlight_style)
1081            });
1082            layout_highlighted_chunks(
1083                chunks,
1084                &style.text,
1085                cx.text_layout_cache,
1086                cx.font_cache,
1087                MAX_LINE_LEN,
1088                rows.len() as usize,
1089            )
1090        }
1091    }
1092
1093    #[allow(clippy::too_many_arguments)]
1094    fn layout_blocks(
1095        &mut self,
1096        rows: Range<u32>,
1097        snapshot: &EditorSnapshot,
1098        editor_width: f32,
1099        scroll_width: f32,
1100        gutter_padding: f32,
1101        gutter_width: f32,
1102        em_width: f32,
1103        text_x: f32,
1104        line_height: f32,
1105        style: &EditorStyle,
1106        line_layouts: &[text_layout::Line],
1107        cx: &mut LayoutContext,
1108    ) -> (f32, Vec<BlockLayout>) {
1109        let editor = if let Some(editor) = self.view.upgrade(cx) {
1110            editor
1111        } else {
1112            return Default::default();
1113        };
1114
1115        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
1116        let scroll_x = snapshot.scroll_position.x();
1117        let (fixed_blocks, non_fixed_blocks) = snapshot
1118            .blocks_in_range(rows.clone())
1119            .partition::<Vec<_>, _>(|(_, block)| match block {
1120                TransformBlock::ExcerptHeader { .. } => false,
1121                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
1122            });
1123        let mut render_block = |block: &TransformBlock, width: f32| {
1124            let mut element = match block {
1125                TransformBlock::Custom(block) => {
1126                    let align_to = block
1127                        .position()
1128                        .to_point(&snapshot.buffer_snapshot)
1129                        .to_display_point(snapshot);
1130                    let anchor_x = text_x
1131                        + if rows.contains(&align_to.row()) {
1132                            line_layouts[(align_to.row() - rows.start) as usize]
1133                                .x_for_index(align_to.column() as usize)
1134                        } else {
1135                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
1136                                .x_for_index(align_to.column() as usize)
1137                        };
1138
1139                    cx.render(&editor, |_, cx| {
1140                        block.render(&mut BlockContext {
1141                            cx,
1142                            anchor_x,
1143                            gutter_padding,
1144                            line_height,
1145                            scroll_x,
1146                            gutter_width,
1147                            em_width,
1148                        })
1149                    })
1150                }
1151                TransformBlock::ExcerptHeader {
1152                    key,
1153                    buffer,
1154                    range,
1155                    starts_new_buffer,
1156                    ..
1157                } => {
1158                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
1159                        let jump_position = range
1160                            .primary
1161                            .as_ref()
1162                            .map_or(range.context.start, |primary| primary.start);
1163                        let jump_action = crate::Jump {
1164                            path: ProjectPath {
1165                                worktree_id: file.worktree_id(cx),
1166                                path: file.path.clone(),
1167                            },
1168                            position: language::ToPoint::to_point(&jump_position, buffer),
1169                            anchor: jump_position,
1170                        };
1171
1172                        enum JumpIcon {}
1173                        cx.render(&editor, |_, cx| {
1174                            MouseEventHandler::<JumpIcon>::new(*key, cx, |state, _| {
1175                                let style = style.jump_icon.style_for(state, false);
1176                                Svg::new("icons/arrow_up_right_8.svg")
1177                                    .with_color(style.color)
1178                                    .constrained()
1179                                    .with_width(style.icon_width)
1180                                    .aligned()
1181                                    .contained()
1182                                    .with_style(style.container)
1183                                    .constrained()
1184                                    .with_width(style.button_width)
1185                                    .with_height(style.button_width)
1186                                    .boxed()
1187                            })
1188                            .with_cursor_style(CursorStyle::PointingHand)
1189                            .on_click(MouseButton::Left, move |_, cx| {
1190                                cx.dispatch_action(jump_action.clone())
1191                            })
1192                            .with_tooltip::<JumpIcon, _>(
1193                                *key,
1194                                "Jump to Buffer".to_string(),
1195                                Some(Box::new(crate::OpenExcerpts)),
1196                                tooltip_style.clone(),
1197                                cx,
1198                            )
1199                            .aligned()
1200                            .flex_float()
1201                            .boxed()
1202                        })
1203                    });
1204
1205                    if *starts_new_buffer {
1206                        let style = &self.style.diagnostic_path_header;
1207                        let font_size =
1208                            (style.text_scale_factor * self.style.text.font_size).round();
1209
1210                        let mut filename = None;
1211                        let mut parent_path = None;
1212                        if let Some(file) = buffer.file() {
1213                            let path = file.path();
1214                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1215                            parent_path =
1216                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1217                        }
1218
1219                        Flex::row()
1220                            .with_child(
1221                                Label::new(
1222                                    filename.unwrap_or_else(|| "untitled".to_string()),
1223                                    style.filename.text.clone().with_font_size(font_size),
1224                                )
1225                                .contained()
1226                                .with_style(style.filename.container)
1227                                .aligned()
1228                                .boxed(),
1229                            )
1230                            .with_children(parent_path.map(|path| {
1231                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1232                                    .contained()
1233                                    .with_style(style.path.container)
1234                                    .aligned()
1235                                    .boxed()
1236                            }))
1237                            .with_children(jump_icon)
1238                            .contained()
1239                            .with_style(style.container)
1240                            .with_padding_left(gutter_padding)
1241                            .with_padding_right(gutter_padding)
1242                            .expanded()
1243                            .named("path header block")
1244                    } else {
1245                        let text_style = self.style.text.clone();
1246                        Flex::row()
1247                            .with_child(Label::new("".to_string(), text_style).boxed())
1248                            .with_children(jump_icon)
1249                            .contained()
1250                            .with_padding_left(gutter_padding)
1251                            .with_padding_right(gutter_padding)
1252                            .expanded()
1253                            .named("collapsed context")
1254                    }
1255                }
1256            };
1257
1258            element.layout(
1259                SizeConstraint {
1260                    min: Vector2F::zero(),
1261                    max: vec2f(width, block.height() as f32 * line_height),
1262                },
1263                cx,
1264            );
1265            element
1266        };
1267
1268        let mut fixed_block_max_width = 0f32;
1269        let mut blocks = Vec::new();
1270        for (row, block) in fixed_blocks {
1271            let element = render_block(block, f32::INFINITY);
1272            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1273            blocks.push(BlockLayout {
1274                row,
1275                element,
1276                style: BlockStyle::Fixed,
1277            });
1278        }
1279        for (row, block) in non_fixed_blocks {
1280            let style = match block {
1281                TransformBlock::Custom(block) => block.style(),
1282                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1283            };
1284            let width = match style {
1285                BlockStyle::Sticky => editor_width,
1286                BlockStyle::Flex => editor_width
1287                    .max(fixed_block_max_width)
1288                    .max(gutter_width + scroll_width),
1289                BlockStyle::Fixed => unreachable!(),
1290            };
1291            let element = render_block(block, width);
1292            blocks.push(BlockLayout {
1293                row,
1294                element,
1295                style,
1296            });
1297        }
1298        (
1299            scroll_width.max(fixed_block_max_width - gutter_width),
1300            blocks,
1301        )
1302    }
1303}
1304
1305impl Element for EditorElement {
1306    type LayoutState = LayoutState;
1307    type PaintState = ();
1308
1309    fn layout(
1310        &mut self,
1311        constraint: SizeConstraint,
1312        cx: &mut LayoutContext,
1313    ) -> (Vector2F, Self::LayoutState) {
1314        let mut size = constraint.max;
1315        if size.x().is_infinite() {
1316            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1317        }
1318
1319        let snapshot = self.snapshot(cx.app);
1320        let style = self.style.clone();
1321        let line_height = style.text.line_height(cx.font_cache);
1322
1323        let gutter_padding;
1324        let gutter_width;
1325        let gutter_margin;
1326        if snapshot.mode == EditorMode::Full {
1327            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
1328            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1329            gutter_margin = -style.text.descent(cx.font_cache);
1330        } else {
1331            gutter_padding = 0.0;
1332            gutter_width = 0.0;
1333            gutter_margin = 0.0;
1334        };
1335
1336        let text_width = size.x() - gutter_width;
1337        let em_width = style.text.em_width(cx.font_cache);
1338        let em_advance = style.text.em_advance(cx.font_cache);
1339        let overscroll = vec2f(em_width, 0.);
1340        let snapshot = self.update_view(cx.app, |view, cx| {
1341            let wrap_width = match view.soft_wrap_mode(cx) {
1342                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
1343                SoftWrap::EditorWidth => {
1344                    Some(text_width - gutter_margin - overscroll.x() - em_width)
1345                }
1346                SoftWrap::Column(column) => Some(column as f32 * em_advance),
1347            };
1348
1349            if view.set_wrap_width(wrap_width, cx) {
1350                view.snapshot(cx)
1351            } else {
1352                snapshot
1353            }
1354        });
1355
1356        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1357        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1358            size.set_y(
1359                scroll_height
1360                    .min(constraint.max_along(Axis::Vertical))
1361                    .max(constraint.min_along(Axis::Vertical))
1362                    .min(line_height * max_lines as f32),
1363            )
1364        } else if let EditorMode::SingleLine = snapshot.mode {
1365            size.set_y(
1366                line_height
1367                    .min(constraint.max_along(Axis::Vertical))
1368                    .max(constraint.min_along(Axis::Vertical)),
1369            )
1370        } else if size.y().is_infinite() {
1371            size.set_y(scroll_height);
1372        }
1373        let gutter_size = vec2f(gutter_width, size.y());
1374        let text_size = vec2f(text_width, size.y());
1375
1376        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
1377            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
1378            let snapshot = view.snapshot(cx);
1379            (autoscroll_horizontally, snapshot)
1380        });
1381
1382        let scroll_position = snapshot.scroll_position();
1383        // The scroll position is a fractional point, the whole number of which represents
1384        // the top of the window in terms of display rows.
1385        let start_row = scroll_position.y() as u32;
1386        let scroll_top = scroll_position.y() * line_height;
1387
1388        // Add 1 to ensure selections bleed off screen
1389        let end_row = 1 + cmp::min(
1390            ((scroll_top + size.y()) / line_height).ceil() as u32,
1391            snapshot.max_point().row(),
1392        );
1393
1394        let start_anchor = if start_row == 0 {
1395            Anchor::min()
1396        } else {
1397            snapshot
1398                .buffer_snapshot
1399                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1400        };
1401        let end_anchor = if end_row > snapshot.max_point().row() {
1402            Anchor::max()
1403        } else {
1404            snapshot
1405                .buffer_snapshot
1406                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1407        };
1408
1409        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1410        let mut active_rows = BTreeMap::new();
1411        let mut highlighted_rows = None;
1412        let mut highlighted_ranges = Vec::new();
1413        self.update_view(cx.app, |view, cx| {
1414            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1415
1416            highlighted_rows = view.highlighted_rows();
1417            let theme = cx.global::<Settings>().theme.as_ref();
1418            highlighted_ranges = view.background_highlights_in_range(
1419                start_anchor.clone()..end_anchor.clone(),
1420                &display_map,
1421                theme,
1422            );
1423
1424            let mut remote_selections = HashMap::default();
1425            for (replica_id, line_mode, selection) in display_map
1426                .buffer_snapshot
1427                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1428            {
1429                // The local selections match the leader's selections.
1430                if Some(replica_id) == view.leader_replica_id {
1431                    continue;
1432                }
1433                remote_selections
1434                    .entry(replica_id)
1435                    .or_insert(Vec::new())
1436                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1437            }
1438            selections.extend(remote_selections);
1439
1440            if view.show_local_selections {
1441                let mut local_selections = view
1442                    .selections
1443                    .disjoint_in_range(start_anchor..end_anchor, cx);
1444                local_selections.extend(view.selections.pending(cx));
1445                for selection in &local_selections {
1446                    let is_empty = selection.start == selection.end;
1447                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1448                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1449                    for row in cmp::max(selection_start.row(), start_row)
1450                        ..=cmp::min(selection_end.row(), end_row)
1451                    {
1452                        let contains_non_empty_selection =
1453                            active_rows.entry(row).or_insert(!is_empty);
1454                        *contains_non_empty_selection |= !is_empty;
1455                    }
1456                }
1457
1458                // Render the local selections in the leader's color when following.
1459                let local_replica_id = view
1460                    .leader_replica_id
1461                    .unwrap_or_else(|| view.replica_id(cx));
1462
1463                selections.push((
1464                    local_replica_id,
1465                    local_selections
1466                        .into_iter()
1467                        .map(|selection| {
1468                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1469                        })
1470                        .collect(),
1471                ));
1472            }
1473        });
1474
1475        let line_number_layouts =
1476            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1477
1478        let diff_hunks = snapshot
1479            .buffer_snapshot
1480            .diff_hunks_in_range(start_row..end_row)
1481            .collect();
1482
1483        let mut max_visible_line_width = 0.0;
1484        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1485        for line in &line_layouts {
1486            if line.width() > max_visible_line_width {
1487                max_visible_line_width = line.width();
1488            }
1489        }
1490
1491        let style = self.style.clone();
1492        let longest_line_width = layout_line(
1493            snapshot.longest_row(),
1494            &snapshot,
1495            &style,
1496            cx.text_layout_cache,
1497        )
1498        .width();
1499        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1500        let em_width = style.text.em_width(cx.font_cache);
1501        let (scroll_width, blocks) = self.layout_blocks(
1502            start_row..end_row,
1503            &snapshot,
1504            size.x(),
1505            scroll_width,
1506            gutter_padding,
1507            gutter_width,
1508            em_width,
1509            gutter_width + gutter_margin,
1510            line_height,
1511            &style,
1512            &line_layouts,
1513            cx,
1514        );
1515
1516        let max_row = snapshot.max_point().row();
1517        let scroll_max = vec2f(
1518            ((scroll_width - text_size.x()) / em_width).max(0.0),
1519            max_row.saturating_sub(1) as f32,
1520        );
1521
1522        self.update_view(cx.app, |view, cx| {
1523            let clamped = view.clamp_scroll_left(scroll_max.x());
1524
1525            let autoscrolled = if autoscroll_horizontally {
1526                view.autoscroll_horizontally(
1527                    start_row,
1528                    text_size.x(),
1529                    scroll_width,
1530                    em_width,
1531                    &line_layouts,
1532                    cx,
1533                )
1534            } else {
1535                false
1536            };
1537
1538            if clamped || autoscrolled {
1539                snapshot = view.snapshot(cx);
1540            }
1541        });
1542
1543        let mut context_menu = None;
1544        let mut code_actions_indicator = None;
1545        let mut hover = None;
1546        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1547            let newest_selection_head = view
1548                .selections
1549                .newest::<usize>(cx)
1550                .head()
1551                .to_display_point(&snapshot);
1552
1553            let style = view.style(cx);
1554            if (start_row..end_row).contains(&newest_selection_head.row()) {
1555                if view.context_menu_visible() {
1556                    context_menu =
1557                        view.render_context_menu(newest_selection_head, style.clone(), cx);
1558                }
1559
1560                code_actions_indicator = view
1561                    .render_code_actions_indicator(&style, cx)
1562                    .map(|indicator| (newest_selection_head.row(), indicator));
1563            }
1564
1565            let visible_rows = start_row..start_row + line_layouts.len() as u32;
1566            hover = view.hover_state.render(&snapshot, &style, visible_rows, cx);
1567        });
1568
1569        if let Some((_, context_menu)) = context_menu.as_mut() {
1570            context_menu.layout(
1571                SizeConstraint {
1572                    min: Vector2F::zero(),
1573                    max: vec2f(
1574                        cx.window_size.x() * 0.7,
1575                        (12. * line_height).min((size.y() - line_height) / 2.),
1576                    ),
1577                },
1578                cx,
1579            );
1580        }
1581
1582        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1583            indicator.layout(
1584                SizeConstraint::strict_along(
1585                    Axis::Vertical,
1586                    line_height * style.code_actions.vertical_scale,
1587                ),
1588                cx,
1589            );
1590        }
1591
1592        if let Some((_, hover_popovers)) = hover.as_mut() {
1593            for hover_popover in hover_popovers.iter_mut() {
1594                hover_popover.layout(
1595                    SizeConstraint {
1596                        min: Vector2F::zero(),
1597                        max: vec2f(
1598                            (120. * em_width) // Default size
1599                                .min(size.x() / 2.) // Shrink to half of the editor width
1600                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
1601                            (16. * line_height) // Default size
1602                                .min(size.y() / 2.) // Shrink to half of the editor height
1603                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
1604                        ),
1605                    },
1606                    cx,
1607                );
1608            }
1609        }
1610
1611        (
1612            size,
1613            LayoutState {
1614                position_map: Arc::new(PositionMap {
1615                    size,
1616                    scroll_max,
1617                    line_layouts,
1618                    line_height,
1619                    em_width,
1620                    em_advance,
1621                    snapshot,
1622                }),
1623                gutter_size,
1624                gutter_padding,
1625                text_size,
1626                gutter_margin,
1627                active_rows,
1628                highlighted_rows,
1629                highlighted_ranges,
1630                line_number_layouts,
1631                diff_hunks,
1632                blocks,
1633                selections,
1634                context_menu,
1635                code_actions_indicator,
1636                hover_popovers: hover,
1637            },
1638        )
1639    }
1640
1641    fn paint(
1642        &mut self,
1643        bounds: RectF,
1644        visible_bounds: RectF,
1645        layout: &mut Self::LayoutState,
1646        cx: &mut PaintContext,
1647    ) -> Self::PaintState {
1648        cx.scene.push_layer(Some(bounds));
1649
1650        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1651        let text_bounds = RectF::new(
1652            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1653            layout.text_size,
1654        );
1655
1656        Self::attach_mouse_handlers(
1657            &self.view,
1658            &layout.position_map,
1659            visible_bounds,
1660            text_bounds,
1661            gutter_bounds,
1662            bounds,
1663            cx,
1664        );
1665
1666        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1667        if layout.gutter_size.x() > 0. {
1668            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1669        }
1670        self.paint_text(text_bounds, visible_bounds, layout, cx);
1671
1672        if !layout.blocks.is_empty() {
1673            cx.scene.push_layer(Some(bounds));
1674            self.paint_blocks(bounds, visible_bounds, layout, cx);
1675            cx.scene.pop_layer();
1676        }
1677
1678        cx.scene.pop_layer();
1679    }
1680
1681    fn dispatch_event(
1682        &mut self,
1683        event: &Event,
1684        _: RectF,
1685        _: RectF,
1686        _: &mut LayoutState,
1687        _: &mut (),
1688        cx: &mut EventContext,
1689    ) -> bool {
1690        if let Event::ModifiersChanged(event) = event {
1691            self.modifiers_changed(*event, cx);
1692        }
1693
1694        false
1695    }
1696
1697    fn rect_for_text_range(
1698        &self,
1699        range_utf16: Range<usize>,
1700        bounds: RectF,
1701        _: RectF,
1702        layout: &Self::LayoutState,
1703        _: &Self::PaintState,
1704        _: &gpui::MeasurementContext,
1705    ) -> Option<RectF> {
1706        let text_bounds = RectF::new(
1707            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1708            layout.text_size,
1709        );
1710        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
1711        let scroll_position = layout.position_map.snapshot.scroll_position();
1712        let start_row = scroll_position.y() as u32;
1713        let scroll_top = scroll_position.y() * layout.position_map.line_height;
1714        let scroll_left = scroll_position.x() * layout.position_map.em_width;
1715
1716        let range_start = OffsetUtf16(range_utf16.start)
1717            .to_display_point(&layout.position_map.snapshot.display_snapshot);
1718        if range_start.row() < start_row {
1719            return None;
1720        }
1721
1722        let line = layout
1723            .position_map
1724            .line_layouts
1725            .get((range_start.row() - start_row) as usize)?;
1726        let range_start_x = line.x_for_index(range_start.column() as usize);
1727        let range_start_y = range_start.row() as f32 * layout.position_map.line_height;
1728        Some(RectF::new(
1729            content_origin
1730                + vec2f(
1731                    range_start_x,
1732                    range_start_y + layout.position_map.line_height,
1733                )
1734                - vec2f(scroll_left, scroll_top),
1735            vec2f(
1736                layout.position_map.em_width,
1737                layout.position_map.line_height,
1738            ),
1739        ))
1740    }
1741
1742    fn debug(
1743        &self,
1744        bounds: RectF,
1745        _: &Self::LayoutState,
1746        _: &Self::PaintState,
1747        _: &gpui::DebugContext,
1748    ) -> json::Value {
1749        json!({
1750            "type": "BufferElement",
1751            "bounds": bounds.to_json()
1752        })
1753    }
1754}
1755
1756pub struct LayoutState {
1757    position_map: Arc<PositionMap>,
1758    gutter_size: Vector2F,
1759    gutter_padding: f32,
1760    gutter_margin: f32,
1761    text_size: Vector2F,
1762    active_rows: BTreeMap<u32, bool>,
1763    highlighted_rows: Option<Range<u32>>,
1764    line_number_layouts: Vec<Option<text_layout::Line>>,
1765    blocks: Vec<BlockLayout>,
1766    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1767    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1768    context_menu: Option<(DisplayPoint, ElementBox)>,
1769    diff_hunks: Vec<DiffHunk<u32>>,
1770    code_actions_indicator: Option<(u32, ElementBox)>,
1771    hover_popovers: Option<(DisplayPoint, Vec<ElementBox>)>,
1772}
1773
1774pub struct PositionMap {
1775    size: Vector2F,
1776    line_height: f32,
1777    scroll_max: Vector2F,
1778    em_width: f32,
1779    em_advance: f32,
1780    line_layouts: Vec<text_layout::Line>,
1781    snapshot: EditorSnapshot,
1782}
1783
1784impl PositionMap {
1785    /// Returns two display points:
1786    /// 1. The nearest *valid* position in the editor
1787    /// 2. An unclipped, potentially *invalid* position that maps directly to
1788    ///    the given pixel position.
1789    fn point_for_position(
1790        &self,
1791        text_bounds: RectF,
1792        position: Vector2F,
1793    ) -> (DisplayPoint, DisplayPoint) {
1794        let scroll_position = self.snapshot.scroll_position();
1795        let position = position - text_bounds.origin();
1796        let y = position.y().max(0.0).min(self.size.y());
1797        let x = position.x() + (scroll_position.x() * self.em_width);
1798        let row = (y / self.line_height + scroll_position.y()) as u32;
1799        let (column, x_overshoot) = if let Some(line) = self
1800            .line_layouts
1801            .get(row as usize - scroll_position.y() as usize)
1802        {
1803            if let Some(ix) = line.index_for_x(x) {
1804                (ix as u32, 0.0)
1805            } else {
1806                (line.len() as u32, 0f32.max(x - line.width()))
1807            }
1808        } else {
1809            (0, x)
1810        };
1811
1812        let mut target_point = DisplayPoint::new(row, column);
1813        let point = self.snapshot.clip_point(target_point, Bias::Left);
1814        *target_point.column_mut() += (x_overshoot / self.em_advance) as u32;
1815
1816        (point, target_point)
1817    }
1818}
1819
1820struct BlockLayout {
1821    row: u32,
1822    element: ElementBox,
1823    style: BlockStyle,
1824}
1825
1826fn layout_line(
1827    row: u32,
1828    snapshot: &EditorSnapshot,
1829    style: &EditorStyle,
1830    layout_cache: &TextLayoutCache,
1831) -> text_layout::Line {
1832    let mut line = snapshot.line(row);
1833
1834    if line.len() > MAX_LINE_LEN {
1835        let mut len = MAX_LINE_LEN;
1836        while !line.is_char_boundary(len) {
1837            len -= 1;
1838        }
1839
1840        line.truncate(len);
1841    }
1842
1843    layout_cache.layout_str(
1844        &line,
1845        style.text.font_size,
1846        &[(
1847            snapshot.line_len(row) as usize,
1848            RunStyle {
1849                font_id: style.text.font_id,
1850                color: Color::black(),
1851                underline: Default::default(),
1852            },
1853        )],
1854    )
1855}
1856
1857#[derive(Copy, Clone, PartialEq, Eq, Debug)]
1858pub enum CursorShape {
1859    Bar,
1860    Block,
1861    Underscore,
1862    Hollow,
1863}
1864
1865impl Default for CursorShape {
1866    fn default() -> Self {
1867        CursorShape::Bar
1868    }
1869}
1870
1871#[derive(Debug)]
1872pub struct Cursor {
1873    origin: Vector2F,
1874    block_width: f32,
1875    line_height: f32,
1876    color: Color,
1877    shape: CursorShape,
1878    block_text: Option<Line>,
1879}
1880
1881impl Cursor {
1882    pub fn new(
1883        origin: Vector2F,
1884        block_width: f32,
1885        line_height: f32,
1886        color: Color,
1887        shape: CursorShape,
1888        block_text: Option<Line>,
1889    ) -> Cursor {
1890        Cursor {
1891            origin,
1892            block_width,
1893            line_height,
1894            color,
1895            shape,
1896            block_text,
1897        }
1898    }
1899
1900    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
1901        RectF::new(
1902            self.origin + origin,
1903            vec2f(self.block_width, self.line_height),
1904        )
1905    }
1906
1907    pub fn paint(&self, origin: Vector2F, cx: &mut PaintContext) {
1908        let bounds = match self.shape {
1909            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
1910            CursorShape::Block | CursorShape::Hollow => RectF::new(
1911                self.origin + origin,
1912                vec2f(self.block_width, self.line_height),
1913            ),
1914            CursorShape::Underscore => RectF::new(
1915                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
1916                vec2f(self.block_width, 2.0),
1917            ),
1918        };
1919
1920        //Draw background or border quad
1921        if matches!(self.shape, CursorShape::Hollow) {
1922            cx.scene.push_quad(Quad {
1923                bounds,
1924                background: None,
1925                border: Border::all(1., self.color),
1926                corner_radius: 0.,
1927            });
1928        } else {
1929            cx.scene.push_quad(Quad {
1930                bounds,
1931                background: Some(self.color),
1932                border: Default::default(),
1933                corner_radius: 0.,
1934            });
1935        }
1936
1937        if let Some(block_text) = &self.block_text {
1938            block_text.paint(self.origin + origin, bounds, self.line_height, cx);
1939        }
1940    }
1941
1942    pub fn shape(&self) -> CursorShape {
1943        self.shape
1944    }
1945}
1946
1947#[derive(Debug)]
1948pub struct HighlightedRange {
1949    pub start_y: f32,
1950    pub line_height: f32,
1951    pub lines: Vec<HighlightedRangeLine>,
1952    pub color: Color,
1953    pub corner_radius: f32,
1954}
1955
1956#[derive(Debug)]
1957pub struct HighlightedRangeLine {
1958    pub start_x: f32,
1959    pub end_x: f32,
1960}
1961
1962impl HighlightedRange {
1963    pub fn paint(&self, bounds: RectF, scene: &mut Scene) {
1964        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1965            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1966            self.paint_lines(
1967                self.start_y + self.line_height,
1968                &self.lines[1..],
1969                bounds,
1970                scene,
1971            );
1972        } else {
1973            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1974        }
1975    }
1976
1977    fn paint_lines(
1978        &self,
1979        start_y: f32,
1980        lines: &[HighlightedRangeLine],
1981        bounds: RectF,
1982        scene: &mut Scene,
1983    ) {
1984        if lines.is_empty() {
1985            return;
1986        }
1987
1988        let mut path = PathBuilder::new();
1989        let first_line = lines.first().unwrap();
1990        let last_line = lines.last().unwrap();
1991
1992        let first_top_left = vec2f(first_line.start_x, start_y);
1993        let first_top_right = vec2f(first_line.end_x, start_y);
1994
1995        let curve_height = vec2f(0., self.corner_radius);
1996        let curve_width = |start_x: f32, end_x: f32| {
1997            let max = (end_x - start_x) / 2.;
1998            let width = if max < self.corner_radius {
1999                max
2000            } else {
2001                self.corner_radius
2002            };
2003
2004            vec2f(width, 0.)
2005        };
2006
2007        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
2008        path.reset(first_top_right - top_curve_width);
2009        path.curve_to(first_top_right + curve_height, first_top_right);
2010
2011        let mut iter = lines.iter().enumerate().peekable();
2012        while let Some((ix, line)) = iter.next() {
2013            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
2014
2015            if let Some((_, next_line)) = iter.peek() {
2016                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
2017
2018                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
2019                    Ordering::Equal => {
2020                        path.line_to(bottom_right);
2021                    }
2022                    Ordering::Less => {
2023                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
2024                        path.line_to(bottom_right - curve_height);
2025                        if self.corner_radius > 0. {
2026                            path.curve_to(bottom_right - curve_width, bottom_right);
2027                        }
2028                        path.line_to(next_top_right + curve_width);
2029                        if self.corner_radius > 0. {
2030                            path.curve_to(next_top_right + curve_height, next_top_right);
2031                        }
2032                    }
2033                    Ordering::Greater => {
2034                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
2035                        path.line_to(bottom_right - curve_height);
2036                        if self.corner_radius > 0. {
2037                            path.curve_to(bottom_right + curve_width, bottom_right);
2038                        }
2039                        path.line_to(next_top_right - curve_width);
2040                        if self.corner_radius > 0. {
2041                            path.curve_to(next_top_right + curve_height, next_top_right);
2042                        }
2043                    }
2044                }
2045            } else {
2046                let curve_width = curve_width(line.start_x, line.end_x);
2047                path.line_to(bottom_right - curve_height);
2048                if self.corner_radius > 0. {
2049                    path.curve_to(bottom_right - curve_width, bottom_right);
2050                }
2051
2052                let bottom_left = vec2f(line.start_x, bottom_right.y());
2053                path.line_to(bottom_left + curve_width);
2054                if self.corner_radius > 0. {
2055                    path.curve_to(bottom_left - curve_height, bottom_left);
2056                }
2057            }
2058        }
2059
2060        if first_line.start_x > last_line.start_x {
2061            let curve_width = curve_width(last_line.start_x, first_line.start_x);
2062            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
2063            path.line_to(second_top_left + curve_height);
2064            if self.corner_radius > 0. {
2065                path.curve_to(second_top_left + curve_width, second_top_left);
2066            }
2067            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
2068            path.line_to(first_bottom_left - curve_width);
2069            if self.corner_radius > 0. {
2070                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
2071            }
2072        }
2073
2074        path.line_to(first_top_left + curve_height);
2075        if self.corner_radius > 0. {
2076            path.curve_to(first_top_left + top_curve_width, first_top_left);
2077        }
2078        path.line_to(first_top_right - top_curve_width);
2079
2080        scene.push_path(path.build(self.color, Some(bounds)));
2081    }
2082}
2083
2084pub fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
2085    delta.powf(1.5) / 100.0
2086}
2087
2088fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
2089    delta.powf(1.2) / 300.0
2090}
2091
2092#[cfg(test)]
2093mod tests {
2094    use std::sync::Arc;
2095
2096    use super::*;
2097    use crate::{
2098        display_map::{BlockDisposition, BlockProperties},
2099        Editor, MultiBuffer,
2100    };
2101    use settings::Settings;
2102    use util::test::sample_text;
2103
2104    #[gpui::test]
2105    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
2106        cx.set_global(Settings::test(cx));
2107        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
2108        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
2109            Editor::new(EditorMode::Full, buffer, None, None, cx)
2110        });
2111        let element = EditorElement::new(
2112            editor.downgrade(),
2113            editor.read(cx).style(cx),
2114            CursorShape::Bar,
2115        );
2116
2117        let layouts = editor.update(cx, |editor, cx| {
2118            let snapshot = editor.snapshot(cx);
2119            let mut presenter = cx.build_presenter(window_id, 30., Default::default());
2120            let layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
2121            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &layout_cx)
2122        });
2123        assert_eq!(layouts.len(), 6);
2124    }
2125
2126    #[gpui::test]
2127    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
2128        cx.set_global(Settings::test(cx));
2129        let buffer = MultiBuffer::build_simple("", cx);
2130        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
2131            Editor::new(EditorMode::Full, buffer, None, None, cx)
2132        });
2133
2134        editor.update(cx, |editor, cx| {
2135            editor.set_placeholder_text("hello", cx);
2136            editor.insert_blocks(
2137                [BlockProperties {
2138                    style: BlockStyle::Fixed,
2139                    disposition: BlockDisposition::Above,
2140                    height: 3,
2141                    position: Anchor::min(),
2142                    render: Arc::new(|_| Empty::new().boxed()),
2143                }],
2144                cx,
2145            );
2146
2147            // Blur the editor so that it displays placeholder text.
2148            cx.blur();
2149        });
2150
2151        let mut element = EditorElement::new(
2152            editor.downgrade(),
2153            editor.read(cx).style(cx),
2154            CursorShape::Bar,
2155        );
2156
2157        let mut scene = Scene::new(1.0);
2158        let mut presenter = cx.build_presenter(window_id, 30., Default::default());
2159        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
2160        let (size, mut state) = element.layout(
2161            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
2162            &mut layout_cx,
2163        );
2164
2165        assert_eq!(state.position_map.line_layouts.len(), 4);
2166        assert_eq!(
2167            state
2168                .line_number_layouts
2169                .iter()
2170                .map(Option::is_some)
2171                .collect::<Vec<_>>(),
2172            &[false, false, false, true]
2173        );
2174
2175        // Don't panic.
2176        let bounds = RectF::new(Default::default(), size);
2177        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
2178        element.paint(bounds, bounds, &mut state, &mut paint_cx);
2179    }
2180}