element.rs

   1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSnapshot, Input, Scroll, Select, SelectPhase,
   4    SoftWrap, ToPoint, MAX_LINE_LEN,
   5};
   6use crate::{
   7    display_map::{DisplaySnapshot, TransformBlock},
   8    EditorStyle, GoToDefinition, Hover,
   9};
  10use clock::ReplicaId;
  11use collections::{BTreeMap, HashMap};
  12use gpui::{
  13    color::Color,
  14    elements::*,
  15    fonts::{HighlightStyle, Underline},
  16    geometry::{
  17        rect::RectF,
  18        vector::{vec2f, Vector2F},
  19        PathBuilder,
  20    },
  21    json::{self, ToJson},
  22    platform::CursorStyle,
  23    text_layout::{self, Line, RunStyle, TextLayoutCache},
  24    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext,
  25    LayoutContext, MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext,
  26    WeakViewHandle,
  27};
  28use json::json;
  29use language::{Bias, DiagnosticSeverity, Selection};
  30use settings::Settings;
  31use smallvec::SmallVec;
  32use std::{
  33    cmp::{self, Ordering},
  34    fmt::Write,
  35    iter,
  36    ops::Range,
  37};
  38
  39struct SelectionLayout {
  40    head: DisplayPoint,
  41    range: Range<DisplayPoint>,
  42}
  43
  44impl SelectionLayout {
  45    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  46        selection: Selection<T>,
  47        line_mode: bool,
  48        map: &DisplaySnapshot,
  49    ) -> Self {
  50        if line_mode {
  51            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  52            let point_range = map.expand_to_line(selection.range());
  53            Self {
  54                head: selection.head().to_display_point(map),
  55                range: point_range.start.to_display_point(map)
  56                    ..point_range.end.to_display_point(map),
  57            }
  58        } else {
  59            let selection = selection.map(|p| p.to_display_point(map));
  60            Self {
  61                head: selection.head(),
  62                range: selection.range(),
  63            }
  64        }
  65    }
  66}
  67
  68pub struct EditorElement {
  69    view: WeakViewHandle<Editor>,
  70    style: EditorStyle,
  71    cursor_shape: CursorShape,
  72}
  73
  74impl EditorElement {
  75    pub fn new(
  76        view: WeakViewHandle<Editor>,
  77        style: EditorStyle,
  78        cursor_shape: CursorShape,
  79    ) -> Self {
  80        Self {
  81            view,
  82            style,
  83            cursor_shape,
  84        }
  85    }
  86
  87    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  88        self.view.upgrade(cx).unwrap().read(cx)
  89    }
  90
  91    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
  92    where
  93        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
  94    {
  95        self.view.upgrade(cx).unwrap().update(cx, f)
  96    }
  97
  98    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
  99        self.update_view(cx, |view, cx| view.snapshot(cx))
 100    }
 101
 102    fn mouse_down(
 103        &self,
 104        position: Vector2F,
 105        cmd: bool,
 106        alt: bool,
 107        shift: bool,
 108        mut click_count: usize,
 109        layout: &mut LayoutState,
 110        paint: &mut PaintState,
 111        cx: &mut EventContext,
 112    ) -> bool {
 113        if paint.gutter_bounds.contains_point(position) {
 114            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 115        } else if !paint.text_bounds.contains_point(position) {
 116            return false;
 117        }
 118
 119        let snapshot = self.snapshot(cx.app);
 120        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 121
 122        if cmd {
 123            cx.dispatch_action(GoToDefinitionAt {
 124                location: Some(position),
 125            });
 126        } else if shift && alt {
 127            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 128                position,
 129                overshoot: overshoot.column(),
 130            }));
 131        } else if shift {
 132            cx.dispatch_action(Select(SelectPhase::Extend {
 133                position,
 134                click_count,
 135            }));
 136        } else {
 137            cx.dispatch_action(Select(SelectPhase::Begin {
 138                position,
 139                add: alt,
 140                click_count,
 141            }));
 142        }
 143
 144        true
 145    }
 146
 147    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
 148        if self.view(cx.app.as_ref()).is_selecting() {
 149            cx.dispatch_action(Select(SelectPhase::End));
 150            true
 151        } else {
 152            false
 153        }
 154    }
 155
 156    fn mouse_dragged(
 157        &self,
 158        position: Vector2F,
 159        layout: &mut LayoutState,
 160        paint: &mut PaintState,
 161        cx: &mut EventContext,
 162    ) -> bool {
 163        let view = self.view(cx.app.as_ref());
 164
 165        if view.is_selecting() {
 166            let rect = paint.text_bounds;
 167            let mut scroll_delta = Vector2F::zero();
 168
 169            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 170            let top = rect.origin_y() + vertical_margin;
 171            let bottom = rect.lower_left().y() - vertical_margin;
 172            if position.y() < top {
 173                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 174            }
 175            if position.y() > bottom {
 176                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 177            }
 178
 179            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 180            let left = rect.origin_x() + horizontal_margin;
 181            let right = rect.upper_right().x() - horizontal_margin;
 182            if position.x() < left {
 183                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 184                    left - position.x(),
 185                ))
 186            }
 187            if position.x() > right {
 188                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 189                    position.x() - right,
 190                ))
 191            }
 192
 193            let snapshot = self.snapshot(cx.app);
 194            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 195
 196            cx.dispatch_action(Select(SelectPhase::Update {
 197                position,
 198                overshoot: overshoot.column(),
 199                scroll_position: (snapshot.scroll_position() + scroll_delta)
 200                    .clamp(Vector2F::zero(), layout.scroll_max),
 201            }));
 202            true
 203        } else {
 204            false
 205        }
 206    }
 207
 208    fn key_down(&self, input: Option<&str>, cx: &mut EventContext) -> bool {
 209        let view = self.view.upgrade(cx.app).unwrap();
 210
 211        if view.is_focused(cx.app) {
 212            if let Some(input) = input {
 213                cx.dispatch_action(Input(input.to_string()));
 214                true
 215            } else {
 216                false
 217            }
 218        } else {
 219            false
 220        }
 221    }
 222
 223    fn scroll(
 224        &self,
 225        position: Vector2F,
 226        mut delta: Vector2F,
 227        precise: bool,
 228        layout: &mut LayoutState,
 229        paint: &mut PaintState,
 230        cx: &mut EventContext,
 231    ) -> bool {
 232        if !paint.bounds.contains_point(position) {
 233            return false;
 234        }
 235
 236        let snapshot = self.snapshot(cx.app);
 237        let max_glyph_width = layout.em_width;
 238        if !precise {
 239            delta *= vec2f(max_glyph_width, layout.line_height);
 240        }
 241
 242        let scroll_position = snapshot.scroll_position();
 243        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 244        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 245        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 246
 247        cx.dispatch_action(Scroll(scroll_position));
 248
 249        true
 250    }
 251
 252    fn paint_background(
 253        &self,
 254        gutter_bounds: RectF,
 255        text_bounds: RectF,
 256        layout: &LayoutState,
 257        cx: &mut PaintContext,
 258    ) {
 259        let bounds = gutter_bounds.union_rect(text_bounds);
 260        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 261        let editor = self.view(cx.app);
 262        cx.scene.push_quad(Quad {
 263            bounds: gutter_bounds,
 264            background: Some(self.style.gutter_background),
 265            border: Border::new(0., Color::transparent_black()),
 266            corner_radius: 0.,
 267        });
 268        cx.scene.push_quad(Quad {
 269            bounds: text_bounds,
 270            background: Some(self.style.background),
 271            border: Border::new(0., Color::transparent_black()),
 272            corner_radius: 0.,
 273        });
 274
 275        if let EditorMode::Full = editor.mode {
 276            let mut active_rows = layout.active_rows.iter().peekable();
 277            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 278                let mut end_row = *start_row;
 279                while active_rows.peek().map_or(false, |r| {
 280                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 281                }) {
 282                    active_rows.next().unwrap();
 283                    end_row += 1;
 284                }
 285
 286                if !contains_non_empty_selection {
 287                    let origin = vec2f(
 288                        bounds.origin_x(),
 289                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 290                    );
 291                    let size = vec2f(
 292                        bounds.width(),
 293                        layout.line_height * (end_row - start_row + 1) as f32,
 294                    );
 295                    cx.scene.push_quad(Quad {
 296                        bounds: RectF::new(origin, size),
 297                        background: Some(self.style.active_line_background),
 298                        border: Border::default(),
 299                        corner_radius: 0.,
 300                    });
 301                }
 302            }
 303
 304            if let Some(highlighted_rows) = &layout.highlighted_rows {
 305                let origin = vec2f(
 306                    bounds.origin_x(),
 307                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 308                        - scroll_top,
 309                );
 310                let size = vec2f(
 311                    bounds.width(),
 312                    layout.line_height * highlighted_rows.len() as f32,
 313                );
 314                cx.scene.push_quad(Quad {
 315                    bounds: RectF::new(origin, size),
 316                    background: Some(self.style.highlighted_line_background),
 317                    border: Border::default(),
 318                    corner_radius: 0.,
 319                });
 320            }
 321        }
 322    }
 323
 324    fn paint_gutter(
 325        &mut self,
 326        bounds: RectF,
 327        visible_bounds: RectF,
 328        layout: &mut LayoutState,
 329        cx: &mut PaintContext,
 330    ) {
 331        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 332        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 333            if let Some(line) = line {
 334                let line_origin = bounds.origin()
 335                    + vec2f(
 336                        bounds.width() - line.width() - layout.gutter_padding,
 337                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 338                    );
 339                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 340            }
 341        }
 342
 343        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 344            let mut x = bounds.width() - layout.gutter_padding;
 345            let mut y = *row as f32 * layout.line_height - scroll_top;
 346            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 347            y += (layout.line_height - indicator.size().y()) / 2.;
 348            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 349        }
 350    }
 351
 352    fn paint_text(
 353        &mut self,
 354        bounds: RectF,
 355        visible_bounds: RectF,
 356        layout: &mut LayoutState,
 357        cx: &mut PaintContext,
 358    ) {
 359        let view = self.view(cx.app);
 360        let style = &self.style;
 361        let local_replica_id = view.replica_id(cx);
 362        let scroll_position = layout.snapshot.scroll_position();
 363        let start_row = scroll_position.y() as u32;
 364        let scroll_top = scroll_position.y() * layout.line_height;
 365        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 366        let max_glyph_width = layout.em_width;
 367        let scroll_left = scroll_position.x() * max_glyph_width;
 368        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 369
 370        cx.scene.push_layer(Some(bounds));
 371        cx.scene.push_cursor_region(CursorRegion {
 372            bounds,
 373            style: CursorStyle::IBeam,
 374        });
 375
 376        for (range, color) in &layout.highlighted_ranges {
 377            self.paint_highlighted_range(
 378                range.clone(),
 379                start_row,
 380                end_row,
 381                *color,
 382                0.,
 383                0.15 * layout.line_height,
 384                layout,
 385                content_origin,
 386                scroll_top,
 387                scroll_left,
 388                bounds,
 389                cx,
 390            );
 391        }
 392
 393        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 394        for (replica_id, selections) in &layout.selections {
 395            let selection_style = style.replica_selection_style(*replica_id);
 396            let corner_radius = 0.15 * layout.line_height;
 397
 398            for selection in selections {
 399                self.paint_highlighted_range(
 400                    selection.range.clone(),
 401                    start_row,
 402                    end_row,
 403                    selection_style.selection,
 404                    corner_radius,
 405                    corner_radius * 2.,
 406                    layout,
 407                    content_origin,
 408                    scroll_top,
 409                    scroll_left,
 410                    bounds,
 411                    cx,
 412                );
 413
 414                if view.show_local_cursors() || *replica_id != local_replica_id {
 415                    let cursor_position = selection.head;
 416                    if (start_row..end_row).contains(&cursor_position.row()) {
 417                        let cursor_row_layout =
 418                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 419                        let cursor_column = cursor_position.column() as usize;
 420
 421                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 422                        let mut block_width =
 423                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 424                        if block_width == 0.0 {
 425                            block_width = layout.em_width;
 426                        }
 427
 428                        let block_text =
 429                            if matches!(self.cursor_shape, CursorShape::Block) {
 430                                layout.snapshot.chars_at(cursor_position).next().and_then(
 431                                    |character| {
 432                                        let font_id =
 433                                            cursor_row_layout.font_for_index(cursor_column)?;
 434                                        let text = character.to_string();
 435
 436                                        Some(cx.text_layout_cache.layout_str(
 437                                            &text,
 438                                            cursor_row_layout.font_size(),
 439                                            &[(
 440                                                text.len(),
 441                                                RunStyle {
 442                                                    font_id,
 443                                                    color: style.background,
 444                                                    underline: Default::default(),
 445                                                },
 446                                            )],
 447                                        ))
 448                                    },
 449                                )
 450                            } else {
 451                                None
 452                            };
 453
 454                        let x = cursor_character_x - scroll_left;
 455                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 456                        cursors.push(Cursor {
 457                            color: selection_style.cursor,
 458                            block_width,
 459                            origin: content_origin + vec2f(x, y),
 460                            line_height: layout.line_height,
 461                            shape: self.cursor_shape,
 462                            block_text,
 463                        });
 464                    }
 465                }
 466            }
 467        }
 468
 469        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 470            // Draw glyphs
 471            for (ix, line) in layout.line_layouts.iter().enumerate() {
 472                let row = start_row + ix as u32;
 473                line.paint(
 474                    content_origin
 475                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 476                    visible_text_bounds,
 477                    layout.line_height,
 478                    cx,
 479                );
 480            }
 481        }
 482
 483        cx.scene.push_layer(Some(bounds));
 484        for cursor in cursors {
 485            cursor.paint(cx);
 486        }
 487        cx.scene.pop_layer();
 488
 489        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 490            cx.scene.push_stacking_context(None);
 491
 492            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 493            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 494            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 495            let mut list_origin = content_origin + vec2f(x, y);
 496            let list_height = context_menu.size().y();
 497
 498            if list_origin.y() + list_height > bounds.lower_left().y() {
 499                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 500            }
 501
 502            context_menu.paint(
 503                list_origin,
 504                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 505                cx,
 506            );
 507
 508            cx.scene.pop_stacking_context();
 509        }
 510
 511        if let Some((position, hover_popover)) = layout.hover.as_mut() {
 512            cx.scene.push_stacking_context(None);
 513
 514            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 515            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 516            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 517            let mut popover_origin = content_origin + vec2f(x, y);
 518            let popover_height = hover_popover.size().y();
 519
 520            if popover_origin.y() + popover_height > bounds.lower_left().y() {
 521                popover_origin.set_y(popover_origin.y() - layout.line_height - popover_height);
 522            }
 523
 524            hover_popover.paint(
 525                popover_origin,
 526                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 527                cx,
 528            );
 529
 530            cx.scene.pop_stacking_context();
 531        }
 532
 533        cx.scene.pop_layer();
 534    }
 535
 536    fn paint_highlighted_range(
 537        &self,
 538        range: Range<DisplayPoint>,
 539        start_row: u32,
 540        end_row: u32,
 541        color: Color,
 542        corner_radius: f32,
 543        line_end_overshoot: f32,
 544        layout: &LayoutState,
 545        content_origin: Vector2F,
 546        scroll_top: f32,
 547        scroll_left: f32,
 548        bounds: RectF,
 549        cx: &mut PaintContext,
 550    ) {
 551        if range.start != range.end {
 552            let row_range = if range.end.column() == 0 {
 553                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 554            } else {
 555                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 556            };
 557
 558            let highlighted_range = HighlightedRange {
 559                color,
 560                line_height: layout.line_height,
 561                corner_radius,
 562                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 563                    - scroll_top,
 564                lines: row_range
 565                    .into_iter()
 566                    .map(|row| {
 567                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 568                        HighlightedRangeLine {
 569                            start_x: if row == range.start.row() {
 570                                content_origin.x()
 571                                    + line_layout.x_for_index(range.start.column() as usize)
 572                                    - scroll_left
 573                            } else {
 574                                content_origin.x() - scroll_left
 575                            },
 576                            end_x: if row == range.end.row() {
 577                                content_origin.x()
 578                                    + line_layout.x_for_index(range.end.column() as usize)
 579                                    - scroll_left
 580                            } else {
 581                                content_origin.x() + line_layout.width() + line_end_overshoot
 582                                    - scroll_left
 583                            },
 584                        }
 585                    })
 586                    .collect(),
 587            };
 588
 589            highlighted_range.paint(bounds, cx.scene);
 590        }
 591    }
 592
 593    fn paint_blocks(
 594        &mut self,
 595        bounds: RectF,
 596        visible_bounds: RectF,
 597        layout: &mut LayoutState,
 598        cx: &mut PaintContext,
 599    ) {
 600        let scroll_position = layout.snapshot.scroll_position();
 601        let scroll_left = scroll_position.x() * layout.em_width;
 602        let scroll_top = scroll_position.y() * layout.line_height;
 603
 604        for (row, element) in &mut layout.blocks {
 605            let origin = bounds.origin()
 606                + vec2f(-scroll_left, *row as f32 * layout.line_height - scroll_top);
 607            element.paint(origin, visible_bounds, cx);
 608        }
 609    }
 610
 611    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 612        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 613        let style = &self.style;
 614
 615        cx.text_layout_cache
 616            .layout_str(
 617                "1".repeat(digit_count).as_str(),
 618                style.text.font_size,
 619                &[(
 620                    digit_count,
 621                    RunStyle {
 622                        font_id: style.text.font_id,
 623                        color: Color::black(),
 624                        underline: Default::default(),
 625                    },
 626                )],
 627            )
 628            .width()
 629    }
 630
 631    fn layout_line_numbers(
 632        &self,
 633        rows: Range<u32>,
 634        active_rows: &BTreeMap<u32, bool>,
 635        snapshot: &EditorSnapshot,
 636        cx: &LayoutContext,
 637    ) -> Vec<Option<text_layout::Line>> {
 638        let style = &self.style;
 639        let include_line_numbers = snapshot.mode == EditorMode::Full;
 640        let mut line_number_layouts = Vec::with_capacity(rows.len());
 641        let mut line_number = String::new();
 642        for (ix, row) in snapshot
 643            .buffer_rows(rows.start)
 644            .take((rows.end - rows.start) as usize)
 645            .enumerate()
 646        {
 647            let display_row = rows.start + ix as u32;
 648            let color = if active_rows.contains_key(&display_row) {
 649                style.line_number_active
 650            } else {
 651                style.line_number
 652            };
 653            if let Some(buffer_row) = row {
 654                if include_line_numbers {
 655                    line_number.clear();
 656                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 657                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 658                        &line_number,
 659                        style.text.font_size,
 660                        &[(
 661                            line_number.len(),
 662                            RunStyle {
 663                                font_id: style.text.font_id,
 664                                color,
 665                                underline: Default::default(),
 666                            },
 667                        )],
 668                    )));
 669                }
 670            } else {
 671                line_number_layouts.push(None);
 672            }
 673        }
 674
 675        line_number_layouts
 676    }
 677
 678    fn layout_lines(
 679        &mut self,
 680        rows: Range<u32>,
 681        snapshot: &EditorSnapshot,
 682        cx: &LayoutContext,
 683    ) -> Vec<text_layout::Line> {
 684        if rows.start >= rows.end {
 685            return Vec::new();
 686        }
 687
 688        // When the editor is empty and unfocused, then show the placeholder.
 689        if snapshot.is_empty() && !snapshot.is_focused() {
 690            let placeholder_style = self
 691                .style
 692                .placeholder_text
 693                .as_ref()
 694                .unwrap_or_else(|| &self.style.text);
 695            let placeholder_text = snapshot.placeholder_text();
 696            let placeholder_lines = placeholder_text
 697                .as_ref()
 698                .map_or("", AsRef::as_ref)
 699                .split('\n')
 700                .skip(rows.start as usize)
 701                .chain(iter::repeat(""))
 702                .take(rows.len());
 703            return placeholder_lines
 704                .map(|line| {
 705                    cx.text_layout_cache.layout_str(
 706                        line,
 707                        placeholder_style.font_size,
 708                        &[(
 709                            line.len(),
 710                            RunStyle {
 711                                font_id: placeholder_style.font_id,
 712                                color: placeholder_style.color,
 713                                underline: Default::default(),
 714                            },
 715                        )],
 716                    )
 717                })
 718                .collect();
 719        } else {
 720            let style = &self.style;
 721            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 722                let mut highlight_style = chunk
 723                    .syntax_highlight_id
 724                    .and_then(|id| id.style(&style.syntax));
 725
 726                if let Some(chunk_highlight) = chunk.highlight_style {
 727                    if let Some(highlight_style) = highlight_style.as_mut() {
 728                        highlight_style.highlight(chunk_highlight);
 729                    } else {
 730                        highlight_style = Some(chunk_highlight);
 731                    }
 732                }
 733
 734                let mut diagnostic_highlight = HighlightStyle::default();
 735
 736                if chunk.is_unnecessary {
 737                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
 738                }
 739
 740                if let Some(severity) = chunk.diagnostic_severity {
 741                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
 742                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
 743                        let diagnostic_style = super::diagnostic_style(severity, true, style);
 744                        diagnostic_highlight.underline = Some(Underline {
 745                            color: Some(diagnostic_style.message.text.color),
 746                            thickness: 1.0.into(),
 747                            squiggly: true,
 748                        });
 749                    }
 750                }
 751
 752                if let Some(highlight_style) = highlight_style.as_mut() {
 753                    highlight_style.highlight(diagnostic_highlight);
 754                } else {
 755                    highlight_style = Some(diagnostic_highlight);
 756                }
 757
 758                (chunk.text, highlight_style)
 759            });
 760            layout_highlighted_chunks(
 761                chunks,
 762                &style.text,
 763                &cx.text_layout_cache,
 764                &cx.font_cache,
 765                MAX_LINE_LEN,
 766                rows.len() as usize,
 767            )
 768        }
 769    }
 770
 771    fn layout_blocks(
 772        &mut self,
 773        rows: Range<u32>,
 774        snapshot: &EditorSnapshot,
 775        width: f32,
 776        gutter_padding: f32,
 777        gutter_width: f32,
 778        em_width: f32,
 779        text_x: f32,
 780        line_height: f32,
 781        style: &EditorStyle,
 782        line_layouts: &[text_layout::Line],
 783        cx: &mut LayoutContext,
 784    ) -> Vec<(u32, ElementBox)> {
 785        let editor = if let Some(editor) = self.view.upgrade(cx) {
 786            editor
 787        } else {
 788            return Default::default();
 789        };
 790
 791        let scroll_x = snapshot.scroll_position.x();
 792        snapshot
 793            .blocks_in_range(rows.clone())
 794            .map(|(block_row, block)| {
 795                let mut element = match block {
 796                    TransformBlock::Custom(block) => {
 797                        let align_to = block
 798                            .position()
 799                            .to_point(&snapshot.buffer_snapshot)
 800                            .to_display_point(snapshot);
 801                        let anchor_x = text_x
 802                            + if rows.contains(&align_to.row()) {
 803                                line_layouts[(align_to.row() - rows.start) as usize]
 804                                    .x_for_index(align_to.column() as usize)
 805                            } else {
 806                                layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 807                                    .x_for_index(align_to.column() as usize)
 808                            };
 809
 810                        cx.render(&editor, |_, cx| {
 811                            block.render(&mut BlockContext {
 812                                cx,
 813                                anchor_x,
 814                                gutter_padding,
 815                                line_height,
 816                                scroll_x,
 817                                gutter_width,
 818                                em_width,
 819                            })
 820                        })
 821                    }
 822                    TransformBlock::ExcerptHeader {
 823                        buffer,
 824                        starts_new_buffer,
 825                        ..
 826                    } => {
 827                        if *starts_new_buffer {
 828                            let style = &self.style.diagnostic_path_header;
 829                            let font_size =
 830                                (style.text_scale_factor * self.style.text.font_size).round();
 831
 832                            let mut filename = None;
 833                            let mut parent_path = None;
 834                            if let Some(path) = buffer.path() {
 835                                filename =
 836                                    path.file_name().map(|f| f.to_string_lossy().to_string());
 837                                parent_path =
 838                                    path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 839                            }
 840
 841                            Flex::row()
 842                                .with_child(
 843                                    Label::new(
 844                                        filename.unwrap_or_else(|| "untitled".to_string()),
 845                                        style.filename.text.clone().with_font_size(font_size),
 846                                    )
 847                                    .contained()
 848                                    .with_style(style.filename.container)
 849                                    .boxed(),
 850                                )
 851                                .with_children(parent_path.map(|path| {
 852                                    Label::new(
 853                                        path,
 854                                        style.path.text.clone().with_font_size(font_size),
 855                                    )
 856                                    .contained()
 857                                    .with_style(style.path.container)
 858                                    .boxed()
 859                                }))
 860                                .aligned()
 861                                .left()
 862                                .contained()
 863                                .with_style(style.container)
 864                                .with_padding_left(gutter_padding + scroll_x * em_width)
 865                                .expanded()
 866                                .named("path header block")
 867                        } else {
 868                            let text_style = self.style.text.clone();
 869                            Label::new("".to_string(), text_style)
 870                                .contained()
 871                                .with_padding_left(gutter_padding + scroll_x * em_width)
 872                                .named("collapsed context")
 873                        }
 874                    }
 875                };
 876
 877                element.layout(
 878                    SizeConstraint {
 879                        min: Vector2F::zero(),
 880                        max: vec2f(width, block.height() as f32 * line_height),
 881                    },
 882                    cx,
 883                );
 884                (block_row, element)
 885            })
 886            .collect()
 887    }
 888}
 889
 890impl Element for EditorElement {
 891    type LayoutState = LayoutState;
 892    type PaintState = PaintState;
 893
 894    fn layout(
 895        &mut self,
 896        constraint: SizeConstraint,
 897        cx: &mut LayoutContext,
 898    ) -> (Vector2F, Self::LayoutState) {
 899        let mut size = constraint.max;
 900        if size.x().is_infinite() {
 901            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
 902        }
 903
 904        let snapshot = self.snapshot(cx.app);
 905        let style = self.style.clone();
 906        let line_height = style.text.line_height(cx.font_cache);
 907
 908        let gutter_padding;
 909        let gutter_width;
 910        let gutter_margin;
 911        if snapshot.mode == EditorMode::Full {
 912            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
 913            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
 914            gutter_margin = -style.text.descent(cx.font_cache);
 915        } else {
 916            gutter_padding = 0.0;
 917            gutter_width = 0.0;
 918            gutter_margin = 0.0;
 919        };
 920
 921        let text_width = size.x() - gutter_width;
 922        let em_width = style.text.em_width(cx.font_cache);
 923        let em_advance = style.text.em_advance(cx.font_cache);
 924        let overscroll = vec2f(em_width, 0.);
 925        let snapshot = self.update_view(cx.app, |view, cx| {
 926            let wrap_width = match view.soft_wrap_mode(cx) {
 927                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
 928                SoftWrap::EditorWidth => {
 929                    Some(text_width - gutter_margin - overscroll.x() - em_width)
 930                }
 931                SoftWrap::Column(column) => Some(column as f32 * em_advance),
 932            };
 933
 934            if view.set_wrap_width(wrap_width, cx) {
 935                view.snapshot(cx)
 936            } else {
 937                snapshot
 938            }
 939        });
 940
 941        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
 942        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
 943            size.set_y(
 944                scroll_height
 945                    .min(constraint.max_along(Axis::Vertical))
 946                    .max(constraint.min_along(Axis::Vertical))
 947                    .min(line_height * max_lines as f32),
 948            )
 949        } else if let EditorMode::SingleLine = snapshot.mode {
 950            size.set_y(
 951                line_height
 952                    .min(constraint.max_along(Axis::Vertical))
 953                    .max(constraint.min_along(Axis::Vertical)),
 954            )
 955        } else if size.y().is_infinite() {
 956            size.set_y(scroll_height);
 957        }
 958        let gutter_size = vec2f(gutter_width, size.y());
 959        let text_size = vec2f(text_width, size.y());
 960
 961        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
 962            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
 963            let snapshot = view.snapshot(cx);
 964            (autoscroll_horizontally, snapshot)
 965        });
 966
 967        let scroll_position = snapshot.scroll_position();
 968        let start_row = scroll_position.y() as u32;
 969        let scroll_top = scroll_position.y() * line_height;
 970
 971        // Add 1 to ensure selections bleed off screen
 972        let end_row = 1 + cmp::min(
 973            ((scroll_top + size.y()) / line_height).ceil() as u32,
 974            snapshot.max_point().row(),
 975        );
 976
 977        let start_anchor = if start_row == 0 {
 978            Anchor::min()
 979        } else {
 980            snapshot
 981                .buffer_snapshot
 982                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
 983        };
 984        let end_anchor = if end_row > snapshot.max_point().row() {
 985            Anchor::max()
 986        } else {
 987            snapshot
 988                .buffer_snapshot
 989                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
 990        };
 991
 992        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
 993        let mut active_rows = BTreeMap::new();
 994        let mut highlighted_rows = None;
 995        let mut highlighted_ranges = Vec::new();
 996        self.update_view(cx.app, |view, cx| {
 997            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
 998
 999            highlighted_rows = view.highlighted_rows();
1000            let theme = cx.global::<Settings>().theme.as_ref();
1001            highlighted_ranges = view.background_highlights_in_range(
1002                start_anchor.clone()..end_anchor.clone(),
1003                &display_map,
1004                theme,
1005            );
1006
1007            let mut remote_selections = HashMap::default();
1008            for (replica_id, line_mode, selection) in display_map
1009                .buffer_snapshot
1010                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1011            {
1012                // The local selections match the leader's selections.
1013                if Some(replica_id) == view.leader_replica_id {
1014                    continue;
1015                }
1016                remote_selections
1017                    .entry(replica_id)
1018                    .or_insert(Vec::new())
1019                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1020            }
1021            selections.extend(remote_selections);
1022
1023            if view.show_local_selections {
1024                let mut local_selections = view
1025                    .selections
1026                    .disjoint_in_range(start_anchor..end_anchor, cx);
1027                local_selections.extend(view.selections.pending(cx));
1028                for selection in &local_selections {
1029                    let is_empty = selection.start == selection.end;
1030                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1031                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1032                    for row in cmp::max(selection_start.row(), start_row)
1033                        ..=cmp::min(selection_end.row(), end_row)
1034                    {
1035                        let contains_non_empty_selection =
1036                            active_rows.entry(row).or_insert(!is_empty);
1037                        *contains_non_empty_selection |= !is_empty;
1038                    }
1039                }
1040
1041                // Render the local selections in the leader's color when following.
1042                let local_replica_id = view.leader_replica_id.unwrap_or(view.replica_id(cx));
1043
1044                selections.push((
1045                    local_replica_id,
1046                    local_selections
1047                        .into_iter()
1048                        .map(|selection| {
1049                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1050                        })
1051                        .collect(),
1052                ));
1053            }
1054        });
1055
1056        let line_number_layouts =
1057            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1058
1059        let mut max_visible_line_width = 0.0;
1060        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1061        for line in &line_layouts {
1062            if line.width() > max_visible_line_width {
1063                max_visible_line_width = line.width();
1064            }
1065        }
1066
1067        let style = self.style.clone();
1068        let longest_line_width = layout_line(
1069            snapshot.longest_row(),
1070            &snapshot,
1071            &style,
1072            cx.text_layout_cache,
1073        )
1074        .width();
1075        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1076        let em_width = style.text.em_width(cx.font_cache);
1077        let max_row = snapshot.max_point().row();
1078        let scroll_max = vec2f(
1079            ((scroll_width - text_size.x()) / em_width).max(0.0),
1080            max_row.saturating_sub(1) as f32,
1081        );
1082
1083        self.update_view(cx.app, |view, cx| {
1084            let clamped = view.clamp_scroll_left(scroll_max.x());
1085            let autoscrolled;
1086            if autoscroll_horizontally {
1087                autoscrolled = view.autoscroll_horizontally(
1088                    start_row,
1089                    text_size.x(),
1090                    scroll_width,
1091                    em_width,
1092                    &line_layouts,
1093                    cx,
1094                );
1095            } else {
1096                autoscrolled = false;
1097            }
1098
1099            if clamped || autoscrolled {
1100                snapshot = view.snapshot(cx);
1101            }
1102        });
1103
1104        let mut context_menu = None;
1105        let mut code_actions_indicator = None;
1106        let mut hover = None;
1107        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1108            let newest_selection_head = view
1109                .selections
1110                .newest::<usize>(cx)
1111                .head()
1112                .to_display_point(&snapshot);
1113
1114            if (start_row..end_row).contains(&newest_selection_head.row()) {
1115                let style = view.style(cx);
1116                if view.context_menu_visible() {
1117                    context_menu = view.render_context_menu(newest_selection_head, style.clone());
1118                }
1119
1120                code_actions_indicator = view
1121                    .render_code_actions_indicator(&style, cx)
1122                    .map(|indicator| (newest_selection_head.row(), indicator));
1123
1124                hover = view.render_hover_popover(style);
1125            }
1126        });
1127
1128        if let Some((_, context_menu)) = context_menu.as_mut() {
1129            context_menu.layout(
1130                SizeConstraint {
1131                    min: Vector2F::zero(),
1132                    max: vec2f(
1133                        f32::INFINITY,
1134                        (12. * line_height).min((size.y() - line_height) / 2.),
1135                    ),
1136                },
1137                cx,
1138            );
1139        }
1140
1141        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1142            indicator.layout(
1143                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
1144                cx,
1145            );
1146        }
1147
1148        if let Some((_, hover)) = hover.as_mut() {
1149            hover.layout(
1150                SizeConstraint {
1151                    min: Vector2F::zero(),
1152                    max: vec2f(
1153                        f32::INFINITY,
1154                        (12. * line_height).min((size.y() - line_height) / 2.),
1155                    ),
1156                },
1157                cx,
1158            );
1159        }
1160
1161        let blocks = self.layout_blocks(
1162            start_row..end_row,
1163            &snapshot,
1164            size.x().max(scroll_width + gutter_width),
1165            gutter_padding,
1166            gutter_width,
1167            em_width,
1168            gutter_width + gutter_margin,
1169            line_height,
1170            &style,
1171            &line_layouts,
1172            cx,
1173        );
1174
1175        (
1176            size,
1177            LayoutState {
1178                size,
1179                scroll_max,
1180                gutter_size,
1181                gutter_padding,
1182                text_size,
1183                gutter_margin,
1184                snapshot,
1185                active_rows,
1186                highlighted_rows,
1187                highlighted_ranges,
1188                line_layouts,
1189                line_number_layouts,
1190                blocks,
1191                line_height,
1192                em_width,
1193                em_advance,
1194                selections,
1195                context_menu,
1196                code_actions_indicator,
1197                hover,
1198            },
1199        )
1200    }
1201
1202    fn paint(
1203        &mut self,
1204        bounds: RectF,
1205        visible_bounds: RectF,
1206        layout: &mut Self::LayoutState,
1207        cx: &mut PaintContext,
1208    ) -> Self::PaintState {
1209        cx.scene.push_layer(Some(bounds));
1210
1211        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1212        let text_bounds = RectF::new(
1213            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1214            layout.text_size,
1215        );
1216
1217        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1218        if layout.gutter_size.x() > 0. {
1219            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1220        }
1221        self.paint_text(text_bounds, visible_bounds, layout, cx);
1222
1223        if !layout.blocks.is_empty() {
1224            cx.scene.push_layer(Some(bounds));
1225            self.paint_blocks(bounds, visible_bounds, layout, cx);
1226            cx.scene.pop_layer();
1227        }
1228
1229        cx.scene.pop_layer();
1230
1231        PaintState {
1232            bounds,
1233            gutter_bounds,
1234            text_bounds,
1235        }
1236    }
1237
1238    fn dispatch_event(
1239        &mut self,
1240        event: &Event,
1241        _: RectF,
1242        _: RectF,
1243        layout: &mut LayoutState,
1244        paint: &mut PaintState,
1245        cx: &mut EventContext,
1246    ) -> bool {
1247        if let Some((_, context_menu)) = &mut layout.context_menu {
1248            if context_menu.dispatch_event(event, cx) {
1249                return true;
1250            }
1251        }
1252
1253        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1254            if indicator.dispatch_event(event, cx) {
1255                return true;
1256            }
1257        }
1258
1259        for (_, block) in &mut layout.blocks {
1260            if block.dispatch_event(event, cx) {
1261                return true;
1262            }
1263        }
1264
1265        match event {
1266            Event::LeftMouseDown {
1267                position,
1268                cmd,
1269                alt,
1270                shift,
1271                click_count,
1272                ..
1273            } => self.mouse_down(
1274                *position,
1275                *cmd,
1276                *alt,
1277                *shift,
1278                *click_count,
1279                layout,
1280                paint,
1281                cx,
1282            ),
1283            Event::LeftMouseUp { position, .. } => self.mouse_up(*position, cx),
1284            Event::LeftMouseDragged { position } => {
1285                self.mouse_dragged(*position, layout, paint, cx)
1286            }
1287            Event::ScrollWheel {
1288                position,
1289                delta,
1290                precise,
1291            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1292            Event::KeyDown { input, .. } => self.key_down(input.as_deref(), cx),
1293            Event::MouseMoved { position, .. } => {
1294                if paint.text_bounds.contains_point(*position) {
1295                    let (point, overshoot) =
1296                        paint.point_for_position(&self.snapshot(cx), layout, *position);
1297                    cx.dispatch_action(Hover { point, overshoot });
1298                    true
1299                } else {
1300                    false
1301                }
1302            }
1303            _ => false,
1304        }
1305    }
1306
1307    fn debug(
1308        &self,
1309        bounds: RectF,
1310        _: &Self::LayoutState,
1311        _: &Self::PaintState,
1312        _: &gpui::DebugContext,
1313    ) -> json::Value {
1314        json!({
1315            "type": "BufferElement",
1316            "bounds": bounds.to_json()
1317        })
1318    }
1319}
1320
1321pub struct LayoutState {
1322    size: Vector2F,
1323    scroll_max: Vector2F,
1324    gutter_size: Vector2F,
1325    gutter_padding: f32,
1326    gutter_margin: f32,
1327    text_size: Vector2F,
1328    snapshot: EditorSnapshot,
1329    active_rows: BTreeMap<u32, bool>,
1330    highlighted_rows: Option<Range<u32>>,
1331    line_layouts: Vec<text_layout::Line>,
1332    line_number_layouts: Vec<Option<text_layout::Line>>,
1333    blocks: Vec<(u32, ElementBox)>,
1334    line_height: f32,
1335    em_width: f32,
1336    em_advance: f32,
1337    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1338    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1339    context_menu: Option<(DisplayPoint, ElementBox)>,
1340    code_actions_indicator: Option<(u32, ElementBox)>,
1341    hover: Option<(DisplayPoint, ElementBox)>,
1342}
1343
1344fn layout_line(
1345    row: u32,
1346    snapshot: &EditorSnapshot,
1347    style: &EditorStyle,
1348    layout_cache: &TextLayoutCache,
1349) -> text_layout::Line {
1350    let mut line = snapshot.line(row);
1351
1352    if line.len() > MAX_LINE_LEN {
1353        let mut len = MAX_LINE_LEN;
1354        while !line.is_char_boundary(len) {
1355            len -= 1;
1356        }
1357
1358        line.truncate(len);
1359    }
1360
1361    layout_cache.layout_str(
1362        &line,
1363        style.text.font_size,
1364        &[(
1365            snapshot.line_len(row) as usize,
1366            RunStyle {
1367                font_id: style.text.font_id,
1368                color: Color::black(),
1369                underline: Default::default(),
1370            },
1371        )],
1372    )
1373}
1374
1375pub struct PaintState {
1376    bounds: RectF,
1377    gutter_bounds: RectF,
1378    text_bounds: RectF,
1379}
1380
1381impl PaintState {
1382    /// Returns two display points. The first is the nearest valid
1383    /// position in the current buffer and the second is the distance to the
1384    /// nearest valid position if there was overshoot.
1385    fn point_for_position(
1386        &self,
1387        snapshot: &EditorSnapshot,
1388        layout: &LayoutState,
1389        position: Vector2F,
1390    ) -> (DisplayPoint, DisplayPoint) {
1391        let scroll_position = snapshot.scroll_position();
1392        let position = position - self.text_bounds.origin();
1393        let y = position.y().max(0.0).min(layout.size.y());
1394        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1395        let row_overshoot = row.saturating_sub(snapshot.max_point().row());
1396        let row = cmp::min(row, snapshot.max_point().row());
1397        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1398        let x = position.x() + (scroll_position.x() * layout.em_width);
1399
1400        let column = if x >= 0.0 {
1401            line.index_for_x(x)
1402                .map(|ix| ix as u32)
1403                .unwrap_or_else(|| snapshot.line_len(row))
1404        } else {
1405            0
1406        };
1407        let column_overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1408
1409        (
1410            DisplayPoint::new(row, column),
1411            DisplayPoint::new(row_overshoot, column_overshoot),
1412        )
1413    }
1414}
1415
1416#[derive(Copy, Clone, PartialEq, Eq)]
1417pub enum CursorShape {
1418    Bar,
1419    Block,
1420    Underscore,
1421}
1422
1423impl Default for CursorShape {
1424    fn default() -> Self {
1425        CursorShape::Bar
1426    }
1427}
1428
1429struct Cursor {
1430    origin: Vector2F,
1431    block_width: f32,
1432    line_height: f32,
1433    color: Color,
1434    shape: CursorShape,
1435    block_text: Option<Line>,
1436}
1437
1438impl Cursor {
1439    fn paint(&self, cx: &mut PaintContext) {
1440        let bounds = match self.shape {
1441            CursorShape::Bar => RectF::new(self.origin, vec2f(2.0, self.line_height)),
1442            CursorShape::Block => {
1443                RectF::new(self.origin, vec2f(self.block_width, self.line_height))
1444            }
1445            CursorShape::Underscore => RectF::new(
1446                self.origin + Vector2F::new(0.0, self.line_height - 2.0),
1447                vec2f(self.block_width, 2.0),
1448            ),
1449        };
1450
1451        cx.scene.push_quad(Quad {
1452            bounds,
1453            background: Some(self.color),
1454            border: Border::new(0., Color::black()),
1455            corner_radius: 0.,
1456        });
1457
1458        if let Some(block_text) = &self.block_text {
1459            block_text.paint(self.origin, bounds, self.line_height, cx);
1460        }
1461    }
1462}
1463
1464#[derive(Debug)]
1465struct HighlightedRange {
1466    start_y: f32,
1467    line_height: f32,
1468    lines: Vec<HighlightedRangeLine>,
1469    color: Color,
1470    corner_radius: f32,
1471}
1472
1473#[derive(Debug)]
1474struct HighlightedRangeLine {
1475    start_x: f32,
1476    end_x: f32,
1477}
1478
1479impl HighlightedRange {
1480    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1481        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1482            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1483            self.paint_lines(
1484                self.start_y + self.line_height,
1485                &self.lines[1..],
1486                bounds,
1487                scene,
1488            );
1489        } else {
1490            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1491        }
1492    }
1493
1494    fn paint_lines(
1495        &self,
1496        start_y: f32,
1497        lines: &[HighlightedRangeLine],
1498        bounds: RectF,
1499        scene: &mut Scene,
1500    ) {
1501        if lines.is_empty() {
1502            return;
1503        }
1504
1505        let mut path = PathBuilder::new();
1506        let first_line = lines.first().unwrap();
1507        let last_line = lines.last().unwrap();
1508
1509        let first_top_left = vec2f(first_line.start_x, start_y);
1510        let first_top_right = vec2f(first_line.end_x, start_y);
1511
1512        let curve_height = vec2f(0., self.corner_radius);
1513        let curve_width = |start_x: f32, end_x: f32| {
1514            let max = (end_x - start_x) / 2.;
1515            let width = if max < self.corner_radius {
1516                max
1517            } else {
1518                self.corner_radius
1519            };
1520
1521            vec2f(width, 0.)
1522        };
1523
1524        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1525        path.reset(first_top_right - top_curve_width);
1526        path.curve_to(first_top_right + curve_height, first_top_right);
1527
1528        let mut iter = lines.iter().enumerate().peekable();
1529        while let Some((ix, line)) = iter.next() {
1530            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1531
1532            if let Some((_, next_line)) = iter.peek() {
1533                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1534
1535                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1536                    Ordering::Equal => {
1537                        path.line_to(bottom_right);
1538                    }
1539                    Ordering::Less => {
1540                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1541                        path.line_to(bottom_right - curve_height);
1542                        if self.corner_radius > 0. {
1543                            path.curve_to(bottom_right - curve_width, bottom_right);
1544                        }
1545                        path.line_to(next_top_right + curve_width);
1546                        if self.corner_radius > 0. {
1547                            path.curve_to(next_top_right + curve_height, next_top_right);
1548                        }
1549                    }
1550                    Ordering::Greater => {
1551                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1552                        path.line_to(bottom_right - curve_height);
1553                        if self.corner_radius > 0. {
1554                            path.curve_to(bottom_right + curve_width, bottom_right);
1555                        }
1556                        path.line_to(next_top_right - curve_width);
1557                        if self.corner_radius > 0. {
1558                            path.curve_to(next_top_right + curve_height, next_top_right);
1559                        }
1560                    }
1561                }
1562            } else {
1563                let curve_width = curve_width(line.start_x, line.end_x);
1564                path.line_to(bottom_right - curve_height);
1565                if self.corner_radius > 0. {
1566                    path.curve_to(bottom_right - curve_width, bottom_right);
1567                }
1568
1569                let bottom_left = vec2f(line.start_x, bottom_right.y());
1570                path.line_to(bottom_left + curve_width);
1571                if self.corner_radius > 0. {
1572                    path.curve_to(bottom_left - curve_height, bottom_left);
1573                }
1574            }
1575        }
1576
1577        if first_line.start_x > last_line.start_x {
1578            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1579            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1580            path.line_to(second_top_left + curve_height);
1581            if self.corner_radius > 0. {
1582                path.curve_to(second_top_left + curve_width, second_top_left);
1583            }
1584            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1585            path.line_to(first_bottom_left - curve_width);
1586            if self.corner_radius > 0. {
1587                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1588            }
1589        }
1590
1591        path.line_to(first_top_left + curve_height);
1592        if self.corner_radius > 0. {
1593            path.curve_to(first_top_left + top_curve_width, first_top_left);
1594        }
1595        path.line_to(first_top_right - top_curve_width);
1596
1597        scene.push_path(path.build(self.color, Some(bounds)));
1598    }
1599}
1600
1601fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1602    delta.powf(1.5) / 100.0
1603}
1604
1605fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1606    delta.powf(1.2) / 300.0
1607}
1608
1609#[cfg(test)]
1610mod tests {
1611    use std::sync::Arc;
1612
1613    use super::*;
1614    use crate::{
1615        display_map::{BlockDisposition, BlockProperties},
1616        Editor, MultiBuffer,
1617    };
1618    use settings::Settings;
1619    use util::test::sample_text;
1620
1621    #[gpui::test]
1622    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1623        cx.set_global(Settings::test(cx));
1624        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1625        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1626            Editor::new(EditorMode::Full, buffer, None, None, None, cx)
1627        });
1628        let element = EditorElement::new(
1629            editor.downgrade(),
1630            editor.read(cx).style(cx),
1631            CursorShape::Bar,
1632        );
1633
1634        let layouts = editor.update(cx, |editor, cx| {
1635            let snapshot = editor.snapshot(cx);
1636            let mut presenter = cx.build_presenter(window_id, 30.);
1637            let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1638            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1639        });
1640        assert_eq!(layouts.len(), 6);
1641    }
1642
1643    #[gpui::test]
1644    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
1645        cx.set_global(Settings::test(cx));
1646        let buffer = MultiBuffer::build_simple("", cx);
1647        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1648            Editor::new(EditorMode::Full, buffer, None, None, None, cx)
1649        });
1650
1651        editor.update(cx, |editor, cx| {
1652            editor.set_placeholder_text("hello", cx);
1653            editor.insert_blocks(
1654                [BlockProperties {
1655                    disposition: BlockDisposition::Above,
1656                    height: 3,
1657                    position: Anchor::min(),
1658                    render: Arc::new(|_| Empty::new().boxed()),
1659                }],
1660                cx,
1661            );
1662
1663            // Blur the editor so that it displays placeholder text.
1664            cx.blur();
1665        });
1666
1667        let mut element = EditorElement::new(
1668            editor.downgrade(),
1669            editor.read(cx).style(cx),
1670            CursorShape::Bar,
1671        );
1672
1673        let mut scene = Scene::new(1.0);
1674        let mut presenter = cx.build_presenter(window_id, 30.);
1675        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1676        let (size, mut state) = element.layout(
1677            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
1678            &mut layout_cx,
1679        );
1680
1681        assert_eq!(state.line_layouts.len(), 4);
1682        assert_eq!(
1683            state
1684                .line_number_layouts
1685                .iter()
1686                .map(Option::is_some)
1687                .collect::<Vec<_>>(),
1688            &[false, false, false, true]
1689        );
1690
1691        // Don't panic.
1692        let bounds = RectF::new(Default::default(), size);
1693        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
1694        element.paint(bounds, bounds, &mut state, &mut paint_cx);
1695    }
1696}