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::{Not, 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            if position.row() >= start_row {
 513                if let Some(cursor_row_layout) = &layout
 514                    .line_layouts
 515                    .get((position.row() - start_row) as usize)
 516                {
 517                    cx.scene.push_stacking_context(None);
 518
 519                    let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 520                    let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 521                    let mut popover_origin = content_origin + vec2f(x, y);
 522                    let popover_height = hover_popover.size().y();
 523
 524                    if popover_origin.y() + popover_height > bounds.lower_left().y() {
 525                        popover_origin
 526                            .set_y(popover_origin.y() - layout.line_height - popover_height);
 527                    }
 528
 529                    hover_popover.paint(
 530                        popover_origin,
 531                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 532                        cx,
 533                    );
 534
 535                    cx.scene.pop_stacking_context();
 536                }
 537            }
 538        }
 539
 540        cx.scene.pop_layer();
 541    }
 542
 543    fn paint_highlighted_range(
 544        &self,
 545        range: Range<DisplayPoint>,
 546        start_row: u32,
 547        end_row: u32,
 548        color: Color,
 549        corner_radius: f32,
 550        line_end_overshoot: f32,
 551        layout: &LayoutState,
 552        content_origin: Vector2F,
 553        scroll_top: f32,
 554        scroll_left: f32,
 555        bounds: RectF,
 556        cx: &mut PaintContext,
 557    ) {
 558        if range.start != range.end {
 559            let row_range = if range.end.column() == 0 {
 560                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 561            } else {
 562                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 563            };
 564
 565            let highlighted_range = HighlightedRange {
 566                color,
 567                line_height: layout.line_height,
 568                corner_radius,
 569                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 570                    - scroll_top,
 571                lines: row_range
 572                    .into_iter()
 573                    .map(|row| {
 574                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 575                        HighlightedRangeLine {
 576                            start_x: if row == range.start.row() {
 577                                content_origin.x()
 578                                    + line_layout.x_for_index(range.start.column() as usize)
 579                                    - scroll_left
 580                            } else {
 581                                content_origin.x() - scroll_left
 582                            },
 583                            end_x: if row == range.end.row() {
 584                                content_origin.x()
 585                                    + line_layout.x_for_index(range.end.column() as usize)
 586                                    - scroll_left
 587                            } else {
 588                                content_origin.x() + line_layout.width() + line_end_overshoot
 589                                    - scroll_left
 590                            },
 591                        }
 592                    })
 593                    .collect(),
 594            };
 595
 596            highlighted_range.paint(bounds, cx.scene);
 597        }
 598    }
 599
 600    fn paint_blocks(
 601        &mut self,
 602        bounds: RectF,
 603        visible_bounds: RectF,
 604        layout: &mut LayoutState,
 605        cx: &mut PaintContext,
 606    ) {
 607        let scroll_position = layout.snapshot.scroll_position();
 608        let scroll_left = scroll_position.x() * layout.em_width;
 609        let scroll_top = scroll_position.y() * layout.line_height;
 610
 611        for (row, element) in &mut layout.blocks {
 612            let origin = bounds.origin()
 613                + vec2f(-scroll_left, *row as f32 * layout.line_height - scroll_top);
 614            element.paint(origin, visible_bounds, cx);
 615        }
 616    }
 617
 618    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 619        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 620        let style = &self.style;
 621
 622        cx.text_layout_cache
 623            .layout_str(
 624                "1".repeat(digit_count).as_str(),
 625                style.text.font_size,
 626                &[(
 627                    digit_count,
 628                    RunStyle {
 629                        font_id: style.text.font_id,
 630                        color: Color::black(),
 631                        underline: Default::default(),
 632                    },
 633                )],
 634            )
 635            .width()
 636    }
 637
 638    fn layout_line_numbers(
 639        &self,
 640        rows: Range<u32>,
 641        active_rows: &BTreeMap<u32, bool>,
 642        snapshot: &EditorSnapshot,
 643        cx: &LayoutContext,
 644    ) -> Vec<Option<text_layout::Line>> {
 645        let style = &self.style;
 646        let include_line_numbers = snapshot.mode == EditorMode::Full;
 647        let mut line_number_layouts = Vec::with_capacity(rows.len());
 648        let mut line_number = String::new();
 649        for (ix, row) in snapshot
 650            .buffer_rows(rows.start)
 651            .take((rows.end - rows.start) as usize)
 652            .enumerate()
 653        {
 654            let display_row = rows.start + ix as u32;
 655            let color = if active_rows.contains_key(&display_row) {
 656                style.line_number_active
 657            } else {
 658                style.line_number
 659            };
 660            if let Some(buffer_row) = row {
 661                if include_line_numbers {
 662                    line_number.clear();
 663                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 664                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 665                        &line_number,
 666                        style.text.font_size,
 667                        &[(
 668                            line_number.len(),
 669                            RunStyle {
 670                                font_id: style.text.font_id,
 671                                color,
 672                                underline: Default::default(),
 673                            },
 674                        )],
 675                    )));
 676                }
 677            } else {
 678                line_number_layouts.push(None);
 679            }
 680        }
 681
 682        line_number_layouts
 683    }
 684
 685    fn layout_lines(
 686        &mut self,
 687        rows: Range<u32>,
 688        snapshot: &EditorSnapshot,
 689        cx: &LayoutContext,
 690    ) -> Vec<text_layout::Line> {
 691        if rows.start >= rows.end {
 692            return Vec::new();
 693        }
 694
 695        // When the editor is empty and unfocused, then show the placeholder.
 696        if snapshot.is_empty() && !snapshot.is_focused() {
 697            let placeholder_style = self
 698                .style
 699                .placeholder_text
 700                .as_ref()
 701                .unwrap_or_else(|| &self.style.text);
 702            let placeholder_text = snapshot.placeholder_text();
 703            let placeholder_lines = placeholder_text
 704                .as_ref()
 705                .map_or("", AsRef::as_ref)
 706                .split('\n')
 707                .skip(rows.start as usize)
 708                .chain(iter::repeat(""))
 709                .take(rows.len());
 710            return placeholder_lines
 711                .map(|line| {
 712                    cx.text_layout_cache.layout_str(
 713                        line,
 714                        placeholder_style.font_size,
 715                        &[(
 716                            line.len(),
 717                            RunStyle {
 718                                font_id: placeholder_style.font_id,
 719                                color: placeholder_style.color,
 720                                underline: Default::default(),
 721                            },
 722                        )],
 723                    )
 724                })
 725                .collect();
 726        } else {
 727            let style = &self.style;
 728            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 729                let mut highlight_style = chunk
 730                    .syntax_highlight_id
 731                    .and_then(|id| id.style(&style.syntax));
 732
 733                if let Some(chunk_highlight) = chunk.highlight_style {
 734                    if let Some(highlight_style) = highlight_style.as_mut() {
 735                        highlight_style.highlight(chunk_highlight);
 736                    } else {
 737                        highlight_style = Some(chunk_highlight);
 738                    }
 739                }
 740
 741                let mut diagnostic_highlight = HighlightStyle::default();
 742
 743                if chunk.is_unnecessary {
 744                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
 745                }
 746
 747                if let Some(severity) = chunk.diagnostic_severity {
 748                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
 749                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
 750                        let diagnostic_style = super::diagnostic_style(severity, true, style);
 751                        diagnostic_highlight.underline = Some(Underline {
 752                            color: Some(diagnostic_style.message.text.color),
 753                            thickness: 1.0.into(),
 754                            squiggly: true,
 755                        });
 756                    }
 757                }
 758
 759                if let Some(highlight_style) = highlight_style.as_mut() {
 760                    highlight_style.highlight(diagnostic_highlight);
 761                } else {
 762                    highlight_style = Some(diagnostic_highlight);
 763                }
 764
 765                (chunk.text, highlight_style)
 766            });
 767            layout_highlighted_chunks(
 768                chunks,
 769                &style.text,
 770                &cx.text_layout_cache,
 771                &cx.font_cache,
 772                MAX_LINE_LEN,
 773                rows.len() as usize,
 774            )
 775        }
 776    }
 777
 778    fn layout_blocks(
 779        &mut self,
 780        rows: Range<u32>,
 781        snapshot: &EditorSnapshot,
 782        width: f32,
 783        gutter_padding: f32,
 784        gutter_width: f32,
 785        em_width: f32,
 786        text_x: f32,
 787        line_height: f32,
 788        style: &EditorStyle,
 789        line_layouts: &[text_layout::Line],
 790        cx: &mut LayoutContext,
 791    ) -> Vec<(u32, ElementBox)> {
 792        let editor = if let Some(editor) = self.view.upgrade(cx) {
 793            editor
 794        } else {
 795            return Default::default();
 796        };
 797
 798        let scroll_x = snapshot.scroll_position.x();
 799        snapshot
 800            .blocks_in_range(rows.clone())
 801            .map(|(block_row, block)| {
 802                let mut element = match block {
 803                    TransformBlock::Custom(block) => {
 804                        let align_to = block
 805                            .position()
 806                            .to_point(&snapshot.buffer_snapshot)
 807                            .to_display_point(snapshot);
 808                        let anchor_x = text_x
 809                            + if rows.contains(&align_to.row()) {
 810                                line_layouts[(align_to.row() - rows.start) as usize]
 811                                    .x_for_index(align_to.column() as usize)
 812                            } else {
 813                                layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 814                                    .x_for_index(align_to.column() as usize)
 815                            };
 816
 817                        cx.render(&editor, |_, cx| {
 818                            block.render(&mut BlockContext {
 819                                cx,
 820                                anchor_x,
 821                                gutter_padding,
 822                                line_height,
 823                                scroll_x,
 824                                gutter_width,
 825                                em_width,
 826                            })
 827                        })
 828                    }
 829                    TransformBlock::ExcerptHeader {
 830                        buffer,
 831                        starts_new_buffer,
 832                        ..
 833                    } => {
 834                        if *starts_new_buffer {
 835                            let style = &self.style.diagnostic_path_header;
 836                            let font_size =
 837                                (style.text_scale_factor * self.style.text.font_size).round();
 838
 839                            let mut filename = None;
 840                            let mut parent_path = None;
 841                            if let Some(path) = buffer.path() {
 842                                filename =
 843                                    path.file_name().map(|f| f.to_string_lossy().to_string());
 844                                parent_path =
 845                                    path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 846                            }
 847
 848                            Flex::row()
 849                                .with_child(
 850                                    Label::new(
 851                                        filename.unwrap_or_else(|| "untitled".to_string()),
 852                                        style.filename.text.clone().with_font_size(font_size),
 853                                    )
 854                                    .contained()
 855                                    .with_style(style.filename.container)
 856                                    .boxed(),
 857                                )
 858                                .with_children(parent_path.map(|path| {
 859                                    Label::new(
 860                                        path,
 861                                        style.path.text.clone().with_font_size(font_size),
 862                                    )
 863                                    .contained()
 864                                    .with_style(style.path.container)
 865                                    .boxed()
 866                                }))
 867                                .aligned()
 868                                .left()
 869                                .contained()
 870                                .with_style(style.container)
 871                                .with_padding_left(gutter_padding + scroll_x * em_width)
 872                                .expanded()
 873                                .named("path header block")
 874                        } else {
 875                            let text_style = self.style.text.clone();
 876                            Label::new("".to_string(), text_style)
 877                                .contained()
 878                                .with_padding_left(gutter_padding + scroll_x * em_width)
 879                                .named("collapsed context")
 880                        }
 881                    }
 882                };
 883
 884                element.layout(
 885                    SizeConstraint {
 886                        min: Vector2F::zero(),
 887                        max: vec2f(width, block.height() as f32 * line_height),
 888                    },
 889                    cx,
 890                );
 891                (block_row, element)
 892            })
 893            .collect()
 894    }
 895}
 896
 897impl Element for EditorElement {
 898    type LayoutState = LayoutState;
 899    type PaintState = PaintState;
 900
 901    fn layout(
 902        &mut self,
 903        constraint: SizeConstraint,
 904        cx: &mut LayoutContext,
 905    ) -> (Vector2F, Self::LayoutState) {
 906        let mut size = constraint.max;
 907        if size.x().is_infinite() {
 908            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
 909        }
 910
 911        let snapshot = self.snapshot(cx.app);
 912        let style = self.style.clone();
 913        let line_height = style.text.line_height(cx.font_cache);
 914
 915        let gutter_padding;
 916        let gutter_width;
 917        let gutter_margin;
 918        if snapshot.mode == EditorMode::Full {
 919            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
 920            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
 921            gutter_margin = -style.text.descent(cx.font_cache);
 922        } else {
 923            gutter_padding = 0.0;
 924            gutter_width = 0.0;
 925            gutter_margin = 0.0;
 926        };
 927
 928        let text_width = size.x() - gutter_width;
 929        let em_width = style.text.em_width(cx.font_cache);
 930        let em_advance = style.text.em_advance(cx.font_cache);
 931        let overscroll = vec2f(em_width, 0.);
 932        let snapshot = self.update_view(cx.app, |view, cx| {
 933            let wrap_width = match view.soft_wrap_mode(cx) {
 934                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
 935                SoftWrap::EditorWidth => {
 936                    Some(text_width - gutter_margin - overscroll.x() - em_width)
 937                }
 938                SoftWrap::Column(column) => Some(column as f32 * em_advance),
 939            };
 940
 941            if view.set_wrap_width(wrap_width, cx) {
 942                view.snapshot(cx)
 943            } else {
 944                snapshot
 945            }
 946        });
 947
 948        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
 949        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
 950            size.set_y(
 951                scroll_height
 952                    .min(constraint.max_along(Axis::Vertical))
 953                    .max(constraint.min_along(Axis::Vertical))
 954                    .min(line_height * max_lines as f32),
 955            )
 956        } else if let EditorMode::SingleLine = snapshot.mode {
 957            size.set_y(
 958                line_height
 959                    .min(constraint.max_along(Axis::Vertical))
 960                    .max(constraint.min_along(Axis::Vertical)),
 961            )
 962        } else if size.y().is_infinite() {
 963            size.set_y(scroll_height);
 964        }
 965        let gutter_size = vec2f(gutter_width, size.y());
 966        let text_size = vec2f(text_width, size.y());
 967
 968        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
 969            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
 970            let snapshot = view.snapshot(cx);
 971            (autoscroll_horizontally, snapshot)
 972        });
 973
 974        let scroll_position = snapshot.scroll_position();
 975        let start_row = scroll_position.y() as u32;
 976        let scroll_top = scroll_position.y() * line_height;
 977
 978        // Add 1 to ensure selections bleed off screen
 979        let end_row = 1 + cmp::min(
 980            ((scroll_top + size.y()) / line_height).ceil() as u32,
 981            snapshot.max_point().row(),
 982        );
 983
 984        let start_anchor = if start_row == 0 {
 985            Anchor::min()
 986        } else {
 987            snapshot
 988                .buffer_snapshot
 989                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
 990        };
 991        let end_anchor = if end_row > snapshot.max_point().row() {
 992            Anchor::max()
 993        } else {
 994            snapshot
 995                .buffer_snapshot
 996                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
 997        };
 998
 999        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1000        let mut active_rows = BTreeMap::new();
1001        let mut highlighted_rows = None;
1002        let mut highlighted_ranges = Vec::new();
1003        self.update_view(cx.app, |view, cx| {
1004            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1005
1006            highlighted_rows = view.highlighted_rows();
1007            let theme = cx.global::<Settings>().theme.as_ref();
1008            highlighted_ranges = view.background_highlights_in_range(
1009                start_anchor.clone()..end_anchor.clone(),
1010                &display_map,
1011                theme,
1012            );
1013
1014            let mut remote_selections = HashMap::default();
1015            for (replica_id, line_mode, selection) in display_map
1016                .buffer_snapshot
1017                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1018            {
1019                // The local selections match the leader's selections.
1020                if Some(replica_id) == view.leader_replica_id {
1021                    continue;
1022                }
1023                remote_selections
1024                    .entry(replica_id)
1025                    .or_insert(Vec::new())
1026                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1027            }
1028            selections.extend(remote_selections);
1029
1030            if view.show_local_selections {
1031                let mut local_selections = view
1032                    .selections
1033                    .disjoint_in_range(start_anchor..end_anchor, cx);
1034                local_selections.extend(view.selections.pending(cx));
1035                for selection in &local_selections {
1036                    let is_empty = selection.start == selection.end;
1037                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1038                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1039                    for row in cmp::max(selection_start.row(), start_row)
1040                        ..=cmp::min(selection_end.row(), end_row)
1041                    {
1042                        let contains_non_empty_selection =
1043                            active_rows.entry(row).or_insert(!is_empty);
1044                        *contains_non_empty_selection |= !is_empty;
1045                    }
1046                }
1047
1048                // Render the local selections in the leader's color when following.
1049                let local_replica_id = view.leader_replica_id.unwrap_or(view.replica_id(cx));
1050
1051                selections.push((
1052                    local_replica_id,
1053                    local_selections
1054                        .into_iter()
1055                        .map(|selection| {
1056                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1057                        })
1058                        .collect(),
1059                ));
1060            }
1061        });
1062
1063        let line_number_layouts =
1064            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1065
1066        let mut max_visible_line_width = 0.0;
1067        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1068        for line in &line_layouts {
1069            if line.width() > max_visible_line_width {
1070                max_visible_line_width = line.width();
1071            }
1072        }
1073
1074        let style = self.style.clone();
1075        let longest_line_width = layout_line(
1076            snapshot.longest_row(),
1077            &snapshot,
1078            &style,
1079            cx.text_layout_cache,
1080        )
1081        .width();
1082        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1083        let em_width = style.text.em_width(cx.font_cache);
1084        let max_row = snapshot.max_point().row();
1085        let scroll_max = vec2f(
1086            ((scroll_width - text_size.x()) / em_width).max(0.0),
1087            max_row.saturating_sub(1) as f32,
1088        );
1089
1090        self.update_view(cx.app, |view, cx| {
1091            let clamped = view.clamp_scroll_left(scroll_max.x());
1092            let autoscrolled;
1093            if autoscroll_horizontally {
1094                autoscrolled = view.autoscroll_horizontally(
1095                    start_row,
1096                    text_size.x(),
1097                    scroll_width,
1098                    em_width,
1099                    &line_layouts,
1100                    cx,
1101                );
1102            } else {
1103                autoscrolled = false;
1104            }
1105
1106            if clamped || autoscrolled {
1107                snapshot = view.snapshot(cx);
1108            }
1109        });
1110
1111        let mut context_menu = None;
1112        let mut code_actions_indicator = None;
1113        let mut hover = None;
1114        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1115            let newest_selection_head = view
1116                .selections
1117                .newest::<usize>(cx)
1118                .head()
1119                .to_display_point(&snapshot);
1120
1121            if (start_row..end_row).contains(&newest_selection_head.row()) {
1122                let style = view.style(cx);
1123                if view.context_menu_visible() {
1124                    context_menu = view.render_context_menu(newest_selection_head, style.clone());
1125                }
1126
1127                code_actions_indicator = view
1128                    .render_code_actions_indicator(&style, cx)
1129                    .map(|indicator| (newest_selection_head.row(), indicator));
1130
1131                hover = view.render_hover_popover(style);
1132            }
1133        });
1134
1135        if let Some((_, context_menu)) = context_menu.as_mut() {
1136            context_menu.layout(
1137                SizeConstraint {
1138                    min: Vector2F::zero(),
1139                    max: vec2f(
1140                        f32::INFINITY,
1141                        (12. * line_height).min((size.y() - line_height) / 2.),
1142                    ),
1143                },
1144                cx,
1145            );
1146        }
1147
1148        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1149            indicator.layout(
1150                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
1151                cx,
1152            );
1153        }
1154
1155        if let Some((_, hover)) = hover.as_mut() {
1156            hover.layout(
1157                SizeConstraint {
1158                    min: Vector2F::zero(),
1159                    max: vec2f(
1160                        f32::INFINITY,
1161                        (12. * line_height).min((size.y() - line_height) / 2.),
1162                    ),
1163                },
1164                cx,
1165            );
1166        }
1167
1168        let blocks = self.layout_blocks(
1169            start_row..end_row,
1170            &snapshot,
1171            size.x().max(scroll_width + gutter_width),
1172            gutter_padding,
1173            gutter_width,
1174            em_width,
1175            gutter_width + gutter_margin,
1176            line_height,
1177            &style,
1178            &line_layouts,
1179            cx,
1180        );
1181
1182        (
1183            size,
1184            LayoutState {
1185                size,
1186                scroll_max,
1187                gutter_size,
1188                gutter_padding,
1189                text_size,
1190                gutter_margin,
1191                snapshot,
1192                active_rows,
1193                highlighted_rows,
1194                highlighted_ranges,
1195                line_layouts,
1196                line_number_layouts,
1197                blocks,
1198                line_height,
1199                em_width,
1200                em_advance,
1201                selections,
1202                context_menu,
1203                code_actions_indicator,
1204                hover,
1205            },
1206        )
1207    }
1208
1209    fn paint(
1210        &mut self,
1211        bounds: RectF,
1212        visible_bounds: RectF,
1213        layout: &mut Self::LayoutState,
1214        cx: &mut PaintContext,
1215    ) -> Self::PaintState {
1216        cx.scene.push_layer(Some(bounds));
1217
1218        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1219        let text_bounds = RectF::new(
1220            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1221            layout.text_size,
1222        );
1223
1224        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1225        if layout.gutter_size.x() > 0. {
1226            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1227        }
1228        self.paint_text(text_bounds, visible_bounds, layout, cx);
1229
1230        if !layout.blocks.is_empty() {
1231            cx.scene.push_layer(Some(bounds));
1232            self.paint_blocks(bounds, visible_bounds, layout, cx);
1233            cx.scene.pop_layer();
1234        }
1235
1236        cx.scene.pop_layer();
1237
1238        PaintState {
1239            bounds,
1240            gutter_bounds,
1241            text_bounds,
1242        }
1243    }
1244
1245    fn dispatch_event(
1246        &mut self,
1247        event: &Event,
1248        _: RectF,
1249        _: RectF,
1250        layout: &mut LayoutState,
1251        paint: &mut PaintState,
1252        cx: &mut EventContext,
1253    ) -> bool {
1254        if let Some((_, context_menu)) = &mut layout.context_menu {
1255            if context_menu.dispatch_event(event, cx) {
1256                return true;
1257            }
1258        }
1259
1260        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1261            if indicator.dispatch_event(event, cx) {
1262                return true;
1263            }
1264        }
1265
1266        for (_, block) in &mut layout.blocks {
1267            if block.dispatch_event(event, cx) {
1268                return true;
1269            }
1270        }
1271
1272        match event {
1273            Event::LeftMouseDown {
1274                position,
1275                cmd,
1276                alt,
1277                shift,
1278                click_count,
1279                ..
1280            } => self.mouse_down(
1281                *position,
1282                *cmd,
1283                *alt,
1284                *shift,
1285                *click_count,
1286                layout,
1287                paint,
1288                cx,
1289            ),
1290            Event::LeftMouseUp { position, .. } => self.mouse_up(*position, cx),
1291            Event::LeftMouseDragged { position } => {
1292                self.mouse_dragged(*position, layout, paint, cx)
1293            }
1294            Event::ScrollWheel {
1295                position,
1296                delta,
1297                precise,
1298            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1299            Event::KeyDown { input, .. } => self.key_down(input.as_deref(), cx),
1300            Event::MouseMoved { position, .. } => {
1301                let point = if paint.text_bounds.contains_point(*position) {
1302                    let (point, overshoot) =
1303                        paint.point_for_position(&self.snapshot(cx), layout, *position);
1304                    if overshoot.is_zero() {
1305                        Some(point)
1306                    } else {
1307                        None
1308                    }
1309                } else {
1310                    None
1311                };
1312
1313                cx.dispatch_action(Hover { point });
1314                true
1315            }
1316            _ => false,
1317        }
1318    }
1319
1320    fn debug(
1321        &self,
1322        bounds: RectF,
1323        _: &Self::LayoutState,
1324        _: &Self::PaintState,
1325        _: &gpui::DebugContext,
1326    ) -> json::Value {
1327        json!({
1328            "type": "BufferElement",
1329            "bounds": bounds.to_json()
1330        })
1331    }
1332}
1333
1334pub struct LayoutState {
1335    size: Vector2F,
1336    scroll_max: Vector2F,
1337    gutter_size: Vector2F,
1338    gutter_padding: f32,
1339    gutter_margin: f32,
1340    text_size: Vector2F,
1341    snapshot: EditorSnapshot,
1342    active_rows: BTreeMap<u32, bool>,
1343    highlighted_rows: Option<Range<u32>>,
1344    line_layouts: Vec<text_layout::Line>,
1345    line_number_layouts: Vec<Option<text_layout::Line>>,
1346    blocks: Vec<(u32, ElementBox)>,
1347    line_height: f32,
1348    em_width: f32,
1349    em_advance: f32,
1350    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1351    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1352    context_menu: Option<(DisplayPoint, ElementBox)>,
1353    code_actions_indicator: Option<(u32, ElementBox)>,
1354    hover: Option<(DisplayPoint, ElementBox)>,
1355}
1356
1357fn layout_line(
1358    row: u32,
1359    snapshot: &EditorSnapshot,
1360    style: &EditorStyle,
1361    layout_cache: &TextLayoutCache,
1362) -> text_layout::Line {
1363    let mut line = snapshot.line(row);
1364
1365    if line.len() > MAX_LINE_LEN {
1366        let mut len = MAX_LINE_LEN;
1367        while !line.is_char_boundary(len) {
1368            len -= 1;
1369        }
1370
1371        line.truncate(len);
1372    }
1373
1374    layout_cache.layout_str(
1375        &line,
1376        style.text.font_size,
1377        &[(
1378            snapshot.line_len(row) as usize,
1379            RunStyle {
1380                font_id: style.text.font_id,
1381                color: Color::black(),
1382                underline: Default::default(),
1383            },
1384        )],
1385    )
1386}
1387
1388pub struct PaintState {
1389    bounds: RectF,
1390    gutter_bounds: RectF,
1391    text_bounds: RectF,
1392}
1393
1394impl PaintState {
1395    /// Returns two display points. The first is the nearest valid
1396    /// position in the current buffer and the second is the distance to the
1397    /// nearest valid position if there was overshoot.
1398    fn point_for_position(
1399        &self,
1400        snapshot: &EditorSnapshot,
1401        layout: &LayoutState,
1402        position: Vector2F,
1403    ) -> (DisplayPoint, DisplayPoint) {
1404        let scroll_position = snapshot.scroll_position();
1405        let position = position - self.text_bounds.origin();
1406        let y = position.y().max(0.0).min(layout.size.y());
1407        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1408        let row_overshoot = row.saturating_sub(snapshot.max_point().row());
1409        let row = cmp::min(row, snapshot.max_point().row());
1410        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1411        let x = position.x() + (scroll_position.x() * layout.em_width);
1412
1413        let column = if x >= 0.0 {
1414            line.index_for_x(x)
1415                .map(|ix| ix as u32)
1416                .unwrap_or_else(|| snapshot.line_len(row))
1417        } else {
1418            0
1419        };
1420        let column_overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1421
1422        (
1423            DisplayPoint::new(row, column),
1424            DisplayPoint::new(row_overshoot, column_overshoot),
1425        )
1426    }
1427}
1428
1429#[derive(Copy, Clone, PartialEq, Eq)]
1430pub enum CursorShape {
1431    Bar,
1432    Block,
1433    Underscore,
1434}
1435
1436impl Default for CursorShape {
1437    fn default() -> Self {
1438        CursorShape::Bar
1439    }
1440}
1441
1442struct Cursor {
1443    origin: Vector2F,
1444    block_width: f32,
1445    line_height: f32,
1446    color: Color,
1447    shape: CursorShape,
1448    block_text: Option<Line>,
1449}
1450
1451impl Cursor {
1452    fn paint(&self, cx: &mut PaintContext) {
1453        let bounds = match self.shape {
1454            CursorShape::Bar => RectF::new(self.origin, vec2f(2.0, self.line_height)),
1455            CursorShape::Block => {
1456                RectF::new(self.origin, vec2f(self.block_width, self.line_height))
1457            }
1458            CursorShape::Underscore => RectF::new(
1459                self.origin + Vector2F::new(0.0, self.line_height - 2.0),
1460                vec2f(self.block_width, 2.0),
1461            ),
1462        };
1463
1464        cx.scene.push_quad(Quad {
1465            bounds,
1466            background: Some(self.color),
1467            border: Border::new(0., Color::black()),
1468            corner_radius: 0.,
1469        });
1470
1471        if let Some(block_text) = &self.block_text {
1472            block_text.paint(self.origin, bounds, self.line_height, cx);
1473        }
1474    }
1475}
1476
1477#[derive(Debug)]
1478struct HighlightedRange {
1479    start_y: f32,
1480    line_height: f32,
1481    lines: Vec<HighlightedRangeLine>,
1482    color: Color,
1483    corner_radius: f32,
1484}
1485
1486#[derive(Debug)]
1487struct HighlightedRangeLine {
1488    start_x: f32,
1489    end_x: f32,
1490}
1491
1492impl HighlightedRange {
1493    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1494        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1495            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1496            self.paint_lines(
1497                self.start_y + self.line_height,
1498                &self.lines[1..],
1499                bounds,
1500                scene,
1501            );
1502        } else {
1503            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1504        }
1505    }
1506
1507    fn paint_lines(
1508        &self,
1509        start_y: f32,
1510        lines: &[HighlightedRangeLine],
1511        bounds: RectF,
1512        scene: &mut Scene,
1513    ) {
1514        if lines.is_empty() {
1515            return;
1516        }
1517
1518        let mut path = PathBuilder::new();
1519        let first_line = lines.first().unwrap();
1520        let last_line = lines.last().unwrap();
1521
1522        let first_top_left = vec2f(first_line.start_x, start_y);
1523        let first_top_right = vec2f(first_line.end_x, start_y);
1524
1525        let curve_height = vec2f(0., self.corner_radius);
1526        let curve_width = |start_x: f32, end_x: f32| {
1527            let max = (end_x - start_x) / 2.;
1528            let width = if max < self.corner_radius {
1529                max
1530            } else {
1531                self.corner_radius
1532            };
1533
1534            vec2f(width, 0.)
1535        };
1536
1537        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1538        path.reset(first_top_right - top_curve_width);
1539        path.curve_to(first_top_right + curve_height, first_top_right);
1540
1541        let mut iter = lines.iter().enumerate().peekable();
1542        while let Some((ix, line)) = iter.next() {
1543            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1544
1545            if let Some((_, next_line)) = iter.peek() {
1546                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1547
1548                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1549                    Ordering::Equal => {
1550                        path.line_to(bottom_right);
1551                    }
1552                    Ordering::Less => {
1553                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1554                        path.line_to(bottom_right - curve_height);
1555                        if self.corner_radius > 0. {
1556                            path.curve_to(bottom_right - curve_width, bottom_right);
1557                        }
1558                        path.line_to(next_top_right + curve_width);
1559                        if self.corner_radius > 0. {
1560                            path.curve_to(next_top_right + curve_height, next_top_right);
1561                        }
1562                    }
1563                    Ordering::Greater => {
1564                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1565                        path.line_to(bottom_right - curve_height);
1566                        if self.corner_radius > 0. {
1567                            path.curve_to(bottom_right + curve_width, bottom_right);
1568                        }
1569                        path.line_to(next_top_right - curve_width);
1570                        if self.corner_radius > 0. {
1571                            path.curve_to(next_top_right + curve_height, next_top_right);
1572                        }
1573                    }
1574                }
1575            } else {
1576                let curve_width = curve_width(line.start_x, line.end_x);
1577                path.line_to(bottom_right - curve_height);
1578                if self.corner_radius > 0. {
1579                    path.curve_to(bottom_right - curve_width, bottom_right);
1580                }
1581
1582                let bottom_left = vec2f(line.start_x, bottom_right.y());
1583                path.line_to(bottom_left + curve_width);
1584                if self.corner_radius > 0. {
1585                    path.curve_to(bottom_left - curve_height, bottom_left);
1586                }
1587            }
1588        }
1589
1590        if first_line.start_x > last_line.start_x {
1591            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1592            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1593            path.line_to(second_top_left + curve_height);
1594            if self.corner_radius > 0. {
1595                path.curve_to(second_top_left + curve_width, second_top_left);
1596            }
1597            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1598            path.line_to(first_bottom_left - curve_width);
1599            if self.corner_radius > 0. {
1600                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1601            }
1602        }
1603
1604        path.line_to(first_top_left + curve_height);
1605        if self.corner_radius > 0. {
1606            path.curve_to(first_top_left + top_curve_width, first_top_left);
1607        }
1608        path.line_to(first_top_right - top_curve_width);
1609
1610        scene.push_path(path.build(self.color, Some(bounds)));
1611    }
1612}
1613
1614fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1615    delta.powf(1.5) / 100.0
1616}
1617
1618fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1619    delta.powf(1.2) / 300.0
1620}
1621
1622#[cfg(test)]
1623mod tests {
1624    use std::sync::Arc;
1625
1626    use super::*;
1627    use crate::{
1628        display_map::{BlockDisposition, BlockProperties},
1629        Editor, MultiBuffer,
1630    };
1631    use settings::Settings;
1632    use util::test::sample_text;
1633
1634    #[gpui::test]
1635    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1636        cx.set_global(Settings::test(cx));
1637        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1638        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1639            Editor::new(EditorMode::Full, buffer, None, None, None, cx)
1640        });
1641        let element = EditorElement::new(
1642            editor.downgrade(),
1643            editor.read(cx).style(cx),
1644            CursorShape::Bar,
1645        );
1646
1647        let layouts = editor.update(cx, |editor, cx| {
1648            let snapshot = editor.snapshot(cx);
1649            let mut presenter = cx.build_presenter(window_id, 30.);
1650            let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1651            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1652        });
1653        assert_eq!(layouts.len(), 6);
1654    }
1655
1656    #[gpui::test]
1657    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
1658        cx.set_global(Settings::test(cx));
1659        let buffer = MultiBuffer::build_simple("", cx);
1660        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1661            Editor::new(EditorMode::Full, buffer, None, None, None, cx)
1662        });
1663
1664        editor.update(cx, |editor, cx| {
1665            editor.set_placeholder_text("hello", cx);
1666            editor.insert_blocks(
1667                [BlockProperties {
1668                    disposition: BlockDisposition::Above,
1669                    height: 3,
1670                    position: Anchor::min(),
1671                    render: Arc::new(|_| Empty::new().boxed()),
1672                }],
1673                cx,
1674            );
1675
1676            // Blur the editor so that it displays placeholder text.
1677            cx.blur();
1678        });
1679
1680        let mut element = EditorElement::new(
1681            editor.downgrade(),
1682            editor.read(cx).style(cx),
1683            CursorShape::Bar,
1684        );
1685
1686        let mut scene = Scene::new(1.0);
1687        let mut presenter = cx.build_presenter(window_id, 30.);
1688        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1689        let (size, mut state) = element.layout(
1690            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
1691            &mut layout_cx,
1692        );
1693
1694        assert_eq!(state.line_layouts.len(), 4);
1695        assert_eq!(
1696            state
1697                .line_number_layouts
1698                .iter()
1699                .map(Option::is_some)
1700                .collect::<Vec<_>>(),
1701            &[false, false, false, true]
1702        );
1703
1704        // Don't panic.
1705        let bounds = RectF::new(Default::default(), size);
1706        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
1707        element.paint(bounds, bounds, &mut state, &mut paint_cx);
1708    }
1709}