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::{BlockStyle, DisplaySnapshot, TransformBlock},
   8    hover_popover::HoverAt,
   9    link_go_to_definition::{CmdChanged, GoToFetchedDefinition, UpdateGoToDefinitionLink},
  10    EditorStyle,
  11};
  12use clock::ReplicaId;
  13use collections::{BTreeMap, HashMap};
  14use gpui::{
  15    color::Color,
  16    elements::*,
  17    fonts::{HighlightStyle, Underline},
  18    geometry::{
  19        rect::RectF,
  20        vector::{vec2f, Vector2F},
  21        PathBuilder,
  22    },
  23    json::{self, ToJson},
  24    platform::CursorStyle,
  25    text_layout::{self, Line, RunStyle, TextLayoutCache},
  26    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext,
  27    LayoutContext, MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext,
  28    WeakViewHandle,
  29};
  30use json::json;
  31use language::{Bias, DiagnosticSeverity, Selection};
  32use project::ProjectPath;
  33use settings::Settings;
  34use smallvec::SmallVec;
  35use std::{
  36    cmp::{self, Ordering},
  37    fmt::Write,
  38    iter,
  39    ops::Range,
  40};
  41
  42struct SelectionLayout {
  43    head: DisplayPoint,
  44    range: Range<DisplayPoint>,
  45}
  46
  47impl SelectionLayout {
  48    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  49        selection: Selection<T>,
  50        line_mode: bool,
  51        map: &DisplaySnapshot,
  52    ) -> Self {
  53        if line_mode {
  54            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  55            let point_range = map.expand_to_line(selection.range());
  56            Self {
  57                head: selection.head().to_display_point(map),
  58                range: point_range.start.to_display_point(map)
  59                    ..point_range.end.to_display_point(map),
  60            }
  61        } else {
  62            let selection = selection.map(|p| p.to_display_point(map));
  63            Self {
  64                head: selection.head(),
  65                range: selection.range(),
  66            }
  67        }
  68    }
  69}
  70
  71pub struct EditorElement {
  72    view: WeakViewHandle<Editor>,
  73    style: EditorStyle,
  74    cursor_shape: CursorShape,
  75}
  76
  77impl EditorElement {
  78    pub fn new(
  79        view: WeakViewHandle<Editor>,
  80        style: EditorStyle,
  81        cursor_shape: CursorShape,
  82    ) -> Self {
  83        Self {
  84            view,
  85            style,
  86            cursor_shape,
  87        }
  88    }
  89
  90    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  91        self.view.upgrade(cx).unwrap().read(cx)
  92    }
  93
  94    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
  95    where
  96        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
  97    {
  98        self.view.upgrade(cx).unwrap().update(cx, f)
  99    }
 100
 101    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
 102        self.update_view(cx, |view, cx| view.snapshot(cx))
 103    }
 104
 105    fn mouse_down(
 106        &self,
 107        position: Vector2F,
 108        cmd: bool,
 109        alt: bool,
 110        shift: bool,
 111        mut click_count: usize,
 112        layout: &mut LayoutState,
 113        paint: &mut PaintState,
 114        cx: &mut EventContext,
 115    ) -> bool {
 116        if cmd && paint.text_bounds.contains_point(position) {
 117            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 118            if overshoot.is_zero() {
 119                cx.dispatch_action(GoToFetchedDefinition { point });
 120                return true;
 121            }
 122        }
 123
 124        if paint.gutter_bounds.contains_point(position) {
 125            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 126        } else if !paint.text_bounds.contains_point(position) {
 127            return false;
 128        }
 129
 130        let snapshot = self.snapshot(cx.app);
 131        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 132
 133        if shift && alt {
 134            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 135                position,
 136                overshoot: overshoot.column(),
 137            }));
 138        } else if shift {
 139            cx.dispatch_action(Select(SelectPhase::Extend {
 140                position,
 141                click_count,
 142            }));
 143        } else {
 144            cx.dispatch_action(Select(SelectPhase::Begin {
 145                position,
 146                add: alt,
 147                click_count,
 148            }));
 149        }
 150
 151        true
 152    }
 153
 154    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
 155        if self.view(cx.app.as_ref()).is_selecting() {
 156            cx.dispatch_action(Select(SelectPhase::End));
 157            true
 158        } else {
 159            false
 160        }
 161    }
 162
 163    fn mouse_dragged(
 164        &self,
 165        position: Vector2F,
 166        layout: &mut LayoutState,
 167        paint: &mut PaintState,
 168        cx: &mut EventContext,
 169    ) -> bool {
 170        let view = self.view(cx.app.as_ref());
 171
 172        if view.is_selecting() {
 173            let rect = paint.text_bounds;
 174            let mut scroll_delta = Vector2F::zero();
 175
 176            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 177            let top = rect.origin_y() + vertical_margin;
 178            let bottom = rect.lower_left().y() - vertical_margin;
 179            if position.y() < top {
 180                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 181            }
 182            if position.y() > bottom {
 183                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 184            }
 185
 186            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 187            let left = rect.origin_x() + horizontal_margin;
 188            let right = rect.upper_right().x() - horizontal_margin;
 189            if position.x() < left {
 190                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 191                    left - position.x(),
 192                ))
 193            }
 194            if position.x() > right {
 195                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 196                    position.x() - right,
 197                ))
 198            }
 199
 200            let snapshot = self.snapshot(cx.app);
 201            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 202
 203            cx.dispatch_action(Select(SelectPhase::Update {
 204                position,
 205                overshoot: overshoot.column(),
 206                scroll_position: (snapshot.scroll_position() + scroll_delta)
 207                    .clamp(Vector2F::zero(), layout.scroll_max),
 208            }));
 209            true
 210        } else {
 211            false
 212        }
 213    }
 214
 215    fn mouse_moved(
 216        &self,
 217        position: Vector2F,
 218        cmd: bool,
 219        layout: &LayoutState,
 220        paint: &PaintState,
 221        cx: &mut EventContext,
 222    ) -> bool {
 223        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 224        // Don't trigger hover popover if mouse is hovering over context menu
 225        let point = if paint.text_bounds.contains_point(position) {
 226            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 227            if overshoot.is_zero() {
 228                Some(point)
 229            } else {
 230                None
 231            }
 232        } else {
 233            None
 234        };
 235
 236        cx.dispatch_action(UpdateGoToDefinitionLink {
 237            point,
 238            cmd_held: cmd,
 239        });
 240
 241        if paint
 242            .context_menu_bounds
 243            .map_or(false, |context_menu_bounds| {
 244                context_menu_bounds.contains_point(*position)
 245            })
 246        {
 247            return false;
 248        }
 249
 250        if paint
 251            .hover_bounds
 252            .map_or(false, |hover_bounds| hover_bounds.contains_point(position))
 253        {
 254            return false;
 255        }
 256
 257        cx.dispatch_action(HoverAt { point });
 258        true
 259    }
 260
 261    fn key_down(&self, input: Option<&str>, cx: &mut EventContext) -> bool {
 262        let view = self.view.upgrade(cx.app).unwrap();
 263
 264        if view.is_focused(cx.app) {
 265            if let Some(input) = input {
 266                cx.dispatch_action(Input(input.to_string()));
 267                true
 268            } else {
 269                false
 270            }
 271        } else {
 272            false
 273        }
 274    }
 275
 276    fn modifiers_changed(&self, cmd: bool, cx: &mut EventContext) -> bool {
 277        cx.dispatch_action(CmdChanged { cmd_down: cmd });
 278        false
 279    }
 280
 281    fn scroll(
 282        &self,
 283        position: Vector2F,
 284        mut delta: Vector2F,
 285        precise: bool,
 286        layout: &mut LayoutState,
 287        paint: &mut PaintState,
 288        cx: &mut EventContext,
 289    ) -> bool {
 290        if !paint.bounds.contains_point(position) {
 291            return false;
 292        }
 293
 294        let snapshot = self.snapshot(cx.app);
 295        let max_glyph_width = layout.em_width;
 296        if !precise {
 297            delta *= vec2f(max_glyph_width, layout.line_height);
 298        }
 299
 300        let scroll_position = snapshot.scroll_position();
 301        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 302        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 303        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 304
 305        cx.dispatch_action(Scroll(scroll_position));
 306
 307        true
 308    }
 309
 310    fn paint_background(
 311        &self,
 312        gutter_bounds: RectF,
 313        text_bounds: RectF,
 314        layout: &LayoutState,
 315        cx: &mut PaintContext,
 316    ) {
 317        let bounds = gutter_bounds.union_rect(text_bounds);
 318        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 319        let editor = self.view(cx.app);
 320        cx.scene.push_quad(Quad {
 321            bounds: gutter_bounds,
 322            background: Some(self.style.gutter_background),
 323            border: Border::new(0., Color::transparent_black()),
 324            corner_radius: 0.,
 325        });
 326        cx.scene.push_quad(Quad {
 327            bounds: text_bounds,
 328            background: Some(self.style.background),
 329            border: Border::new(0., Color::transparent_black()),
 330            corner_radius: 0.,
 331        });
 332
 333        if let EditorMode::Full = editor.mode {
 334            let mut active_rows = layout.active_rows.iter().peekable();
 335            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 336                let mut end_row = *start_row;
 337                while active_rows.peek().map_or(false, |r| {
 338                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 339                }) {
 340                    active_rows.next().unwrap();
 341                    end_row += 1;
 342                }
 343
 344                if !contains_non_empty_selection {
 345                    let origin = vec2f(
 346                        bounds.origin_x(),
 347                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 348                    );
 349                    let size = vec2f(
 350                        bounds.width(),
 351                        layout.line_height * (end_row - start_row + 1) as f32,
 352                    );
 353                    cx.scene.push_quad(Quad {
 354                        bounds: RectF::new(origin, size),
 355                        background: Some(self.style.active_line_background),
 356                        border: Border::default(),
 357                        corner_radius: 0.,
 358                    });
 359                }
 360            }
 361
 362            if let Some(highlighted_rows) = &layout.highlighted_rows {
 363                let origin = vec2f(
 364                    bounds.origin_x(),
 365                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 366                        - scroll_top,
 367                );
 368                let size = vec2f(
 369                    bounds.width(),
 370                    layout.line_height * highlighted_rows.len() as f32,
 371                );
 372                cx.scene.push_quad(Quad {
 373                    bounds: RectF::new(origin, size),
 374                    background: Some(self.style.highlighted_line_background),
 375                    border: Border::default(),
 376                    corner_radius: 0.,
 377                });
 378            }
 379        }
 380    }
 381
 382    fn paint_gutter(
 383        &mut self,
 384        bounds: RectF,
 385        visible_bounds: RectF,
 386        layout: &mut LayoutState,
 387        cx: &mut PaintContext,
 388    ) {
 389        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 390        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 391            if let Some(line) = line {
 392                let line_origin = bounds.origin()
 393                    + vec2f(
 394                        bounds.width() - line.width() - layout.gutter_padding,
 395                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 396                    );
 397                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 398            }
 399        }
 400
 401        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 402            let mut x = bounds.width() - layout.gutter_padding;
 403            let mut y = *row as f32 * layout.line_height - scroll_top;
 404            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 405            y += (layout.line_height - indicator.size().y()) / 2.;
 406            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 407        }
 408    }
 409
 410    fn paint_text(
 411        &mut self,
 412        bounds: RectF,
 413        visible_bounds: RectF,
 414        layout: &mut LayoutState,
 415        paint: &mut PaintState,
 416        cx: &mut PaintContext,
 417    ) {
 418        let view = self.view(cx.app);
 419        let style = &self.style;
 420        let local_replica_id = view.replica_id(cx);
 421        let scroll_position = layout.snapshot.scroll_position();
 422        let start_row = scroll_position.y() as u32;
 423        let scroll_top = scroll_position.y() * layout.line_height;
 424        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 425        let max_glyph_width = layout.em_width;
 426        let scroll_left = scroll_position.x() * max_glyph_width;
 427        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 428
 429        cx.scene.push_layer(Some(bounds));
 430        cx.scene.push_cursor_region(CursorRegion {
 431            bounds,
 432            style: CursorStyle::IBeam,
 433        });
 434
 435        for (range, color) in &layout.highlighted_ranges {
 436            self.paint_highlighted_range(
 437                range.clone(),
 438                start_row,
 439                end_row,
 440                *color,
 441                0.,
 442                0.15 * layout.line_height,
 443                layout,
 444                content_origin,
 445                scroll_top,
 446                scroll_left,
 447                bounds,
 448                cx,
 449            );
 450        }
 451
 452        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 453        for (replica_id, selections) in &layout.selections {
 454            let selection_style = style.replica_selection_style(*replica_id);
 455            let corner_radius = 0.15 * layout.line_height;
 456
 457            for selection in selections {
 458                self.paint_highlighted_range(
 459                    selection.range.clone(),
 460                    start_row,
 461                    end_row,
 462                    selection_style.selection,
 463                    corner_radius,
 464                    corner_radius * 2.,
 465                    layout,
 466                    content_origin,
 467                    scroll_top,
 468                    scroll_left,
 469                    bounds,
 470                    cx,
 471                );
 472
 473                if view.show_local_cursors() || *replica_id != local_replica_id {
 474                    let cursor_position = selection.head;
 475                    if (start_row..end_row).contains(&cursor_position.row()) {
 476                        let cursor_row_layout =
 477                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 478                        let cursor_column = cursor_position.column() as usize;
 479
 480                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 481                        let mut block_width =
 482                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 483                        if block_width == 0.0 {
 484                            block_width = layout.em_width;
 485                        }
 486
 487                        let block_text =
 488                            if matches!(self.cursor_shape, CursorShape::Block) {
 489                                layout.snapshot.chars_at(cursor_position).next().and_then(
 490                                    |character| {
 491                                        let font_id =
 492                                            cursor_row_layout.font_for_index(cursor_column)?;
 493                                        let text = character.to_string();
 494
 495                                        Some(cx.text_layout_cache.layout_str(
 496                                            &text,
 497                                            cursor_row_layout.font_size(),
 498                                            &[(
 499                                                text.len(),
 500                                                RunStyle {
 501                                                    font_id,
 502                                                    color: style.background,
 503                                                    underline: Default::default(),
 504                                                },
 505                                            )],
 506                                        ))
 507                                    },
 508                                )
 509                            } else {
 510                                None
 511                            };
 512
 513                        let x = cursor_character_x - scroll_left;
 514                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 515                        cursors.push(Cursor {
 516                            color: selection_style.cursor,
 517                            block_width,
 518                            origin: content_origin + vec2f(x, y),
 519                            line_height: layout.line_height,
 520                            shape: self.cursor_shape,
 521                            block_text,
 522                        });
 523                    }
 524                }
 525            }
 526        }
 527
 528        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 529            // Draw glyphs
 530            for (ix, line) in layout.line_layouts.iter().enumerate() {
 531                let row = start_row + ix as u32;
 532                line.paint(
 533                    content_origin
 534                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 535                    visible_text_bounds,
 536                    layout.line_height,
 537                    cx,
 538                );
 539            }
 540        }
 541
 542        cx.scene.push_layer(Some(bounds));
 543        for cursor in cursors {
 544            cursor.paint(cx);
 545        }
 546        cx.scene.pop_layer();
 547
 548        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 549            cx.scene.push_stacking_context(None);
 550
 551            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 552            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 553            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 554            let mut list_origin = content_origin + vec2f(x, y);
 555            let list_width = context_menu.size().x();
 556            let list_height = context_menu.size().y();
 557
 558            // Snap the right edge of the list to the right edge of the window if
 559            // its horizontal bounds overflow.
 560            if list_origin.x() + list_width > cx.window_size.x() {
 561                list_origin.set_x((cx.window_size.x() - list_width).max(0.));
 562            }
 563
 564            if list_origin.y() + list_height > bounds.max_y() {
 565                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 566            }
 567
 568            context_menu.paint(
 569                list_origin,
 570                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 571                cx,
 572            );
 573
 574            paint.context_menu_bounds = Some(RectF::new(list_origin, context_menu.size()));
 575
 576            cx.scene.pop_stacking_context();
 577        }
 578
 579        if let Some((position, hover_popover)) = layout.hover.as_mut() {
 580            cx.scene.push_stacking_context(None);
 581
 582            // This is safe because we check on layout whether the required row is available
 583            let hovered_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 584            let size = hover_popover.size();
 585            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 586            let y = position.row() as f32 * layout.line_height - scroll_top - size.y();
 587            let mut popover_origin = content_origin + vec2f(x, y);
 588
 589            if popover_origin.y() < 0.0 {
 590                popover_origin.set_y(popover_origin.y() + layout.line_height + size.y());
 591            }
 592
 593            let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 594            if x_out_of_bounds < 0.0 {
 595                popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 596            }
 597
 598            hover_popover.paint(
 599                popover_origin,
 600                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 601                cx,
 602            );
 603
 604            paint.hover_bounds = Some(
 605                RectF::new(popover_origin, hover_popover.size()).dilate(Vector2F::new(0., 5.)),
 606            );
 607
 608            cx.scene.pop_stacking_context();
 609        }
 610
 611        cx.scene.pop_layer();
 612    }
 613
 614    fn paint_highlighted_range(
 615        &self,
 616        range: Range<DisplayPoint>,
 617        start_row: u32,
 618        end_row: u32,
 619        color: Color,
 620        corner_radius: f32,
 621        line_end_overshoot: f32,
 622        layout: &LayoutState,
 623        content_origin: Vector2F,
 624        scroll_top: f32,
 625        scroll_left: f32,
 626        bounds: RectF,
 627        cx: &mut PaintContext,
 628    ) {
 629        if range.start != range.end {
 630            let row_range = if range.end.column() == 0 {
 631                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 632            } else {
 633                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 634            };
 635
 636            let highlighted_range = HighlightedRange {
 637                color,
 638                line_height: layout.line_height,
 639                corner_radius,
 640                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 641                    - scroll_top,
 642                lines: row_range
 643                    .into_iter()
 644                    .map(|row| {
 645                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 646                        HighlightedRangeLine {
 647                            start_x: if row == range.start.row() {
 648                                content_origin.x()
 649                                    + line_layout.x_for_index(range.start.column() as usize)
 650                                    - scroll_left
 651                            } else {
 652                                content_origin.x() - scroll_left
 653                            },
 654                            end_x: if row == range.end.row() {
 655                                content_origin.x()
 656                                    + line_layout.x_for_index(range.end.column() as usize)
 657                                    - scroll_left
 658                            } else {
 659                                content_origin.x() + line_layout.width() + line_end_overshoot
 660                                    - scroll_left
 661                            },
 662                        }
 663                    })
 664                    .collect(),
 665            };
 666
 667            highlighted_range.paint(bounds, cx.scene);
 668        }
 669    }
 670
 671    fn paint_blocks(
 672        &mut self,
 673        bounds: RectF,
 674        visible_bounds: RectF,
 675        layout: &mut LayoutState,
 676        cx: &mut PaintContext,
 677    ) {
 678        let scroll_position = layout.snapshot.scroll_position();
 679        let scroll_left = scroll_position.x() * layout.em_width;
 680        let scroll_top = scroll_position.y() * layout.line_height;
 681
 682        for block in &mut layout.blocks {
 683            let mut origin =
 684                bounds.origin() + vec2f(0., block.row as f32 * layout.line_height - scroll_top);
 685            if !matches!(block.style, BlockStyle::Sticky) {
 686                origin += vec2f(-scroll_left, 0.);
 687            }
 688            block.element.paint(origin, visible_bounds, cx);
 689        }
 690    }
 691
 692    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 693        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 694        let style = &self.style;
 695
 696        cx.text_layout_cache
 697            .layout_str(
 698                "1".repeat(digit_count).as_str(),
 699                style.text.font_size,
 700                &[(
 701                    digit_count,
 702                    RunStyle {
 703                        font_id: style.text.font_id,
 704                        color: Color::black(),
 705                        underline: Default::default(),
 706                    },
 707                )],
 708            )
 709            .width()
 710    }
 711
 712    fn layout_line_numbers(
 713        &self,
 714        rows: Range<u32>,
 715        active_rows: &BTreeMap<u32, bool>,
 716        snapshot: &EditorSnapshot,
 717        cx: &LayoutContext,
 718    ) -> Vec<Option<text_layout::Line>> {
 719        let style = &self.style;
 720        let include_line_numbers = snapshot.mode == EditorMode::Full;
 721        let mut line_number_layouts = Vec::with_capacity(rows.len());
 722        let mut line_number = String::new();
 723        for (ix, row) in snapshot
 724            .buffer_rows(rows.start)
 725            .take((rows.end - rows.start) as usize)
 726            .enumerate()
 727        {
 728            let display_row = rows.start + ix as u32;
 729            let color = if active_rows.contains_key(&display_row) {
 730                style.line_number_active
 731            } else {
 732                style.line_number
 733            };
 734            if let Some(buffer_row) = row {
 735                if include_line_numbers {
 736                    line_number.clear();
 737                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 738                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 739                        &line_number,
 740                        style.text.font_size,
 741                        &[(
 742                            line_number.len(),
 743                            RunStyle {
 744                                font_id: style.text.font_id,
 745                                color,
 746                                underline: Default::default(),
 747                            },
 748                        )],
 749                    )));
 750                }
 751            } else {
 752                line_number_layouts.push(None);
 753            }
 754        }
 755
 756        line_number_layouts
 757    }
 758
 759    fn layout_lines(
 760        &mut self,
 761        rows: Range<u32>,
 762        snapshot: &EditorSnapshot,
 763        cx: &LayoutContext,
 764    ) -> Vec<text_layout::Line> {
 765        if rows.start >= rows.end {
 766            return Vec::new();
 767        }
 768
 769        // When the editor is empty and unfocused, then show the placeholder.
 770        if snapshot.is_empty() && !snapshot.is_focused() {
 771            let placeholder_style = self
 772                .style
 773                .placeholder_text
 774                .as_ref()
 775                .unwrap_or_else(|| &self.style.text);
 776            let placeholder_text = snapshot.placeholder_text();
 777            let placeholder_lines = placeholder_text
 778                .as_ref()
 779                .map_or("", AsRef::as_ref)
 780                .split('\n')
 781                .skip(rows.start as usize)
 782                .chain(iter::repeat(""))
 783                .take(rows.len());
 784            return placeholder_lines
 785                .map(|line| {
 786                    cx.text_layout_cache.layout_str(
 787                        line,
 788                        placeholder_style.font_size,
 789                        &[(
 790                            line.len(),
 791                            RunStyle {
 792                                font_id: placeholder_style.font_id,
 793                                color: placeholder_style.color,
 794                                underline: Default::default(),
 795                            },
 796                        )],
 797                    )
 798                })
 799                .collect();
 800        } else {
 801            let style = &self.style;
 802            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 803                let mut highlight_style = chunk
 804                    .syntax_highlight_id
 805                    .and_then(|id| id.style(&style.syntax));
 806
 807                if let Some(chunk_highlight) = chunk.highlight_style {
 808                    if let Some(highlight_style) = highlight_style.as_mut() {
 809                        highlight_style.highlight(chunk_highlight);
 810                    } else {
 811                        highlight_style = Some(chunk_highlight);
 812                    }
 813                }
 814
 815                let mut diagnostic_highlight = HighlightStyle::default();
 816
 817                if chunk.is_unnecessary {
 818                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
 819                }
 820
 821                if let Some(severity) = chunk.diagnostic_severity {
 822                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
 823                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
 824                        let diagnostic_style = super::diagnostic_style(severity, true, style);
 825                        diagnostic_highlight.underline = Some(Underline {
 826                            color: Some(diagnostic_style.message.text.color),
 827                            thickness: 1.0.into(),
 828                            squiggly: true,
 829                        });
 830                    }
 831                }
 832
 833                if let Some(highlight_style) = highlight_style.as_mut() {
 834                    highlight_style.highlight(diagnostic_highlight);
 835                } else {
 836                    highlight_style = Some(diagnostic_highlight);
 837                }
 838
 839                (chunk.text, highlight_style)
 840            });
 841            layout_highlighted_chunks(
 842                chunks,
 843                &style.text,
 844                &cx.text_layout_cache,
 845                &cx.font_cache,
 846                MAX_LINE_LEN,
 847                rows.len() as usize,
 848            )
 849        }
 850    }
 851
 852    fn layout_blocks(
 853        &mut self,
 854        rows: Range<u32>,
 855        snapshot: &EditorSnapshot,
 856        editor_width: f32,
 857        scroll_width: f32,
 858        gutter_padding: f32,
 859        gutter_width: f32,
 860        em_width: f32,
 861        text_x: f32,
 862        line_height: f32,
 863        style: &EditorStyle,
 864        line_layouts: &[text_layout::Line],
 865        cx: &mut LayoutContext,
 866    ) -> (f32, Vec<BlockLayout>) {
 867        let editor = if let Some(editor) = self.view.upgrade(cx) {
 868            editor
 869        } else {
 870            return Default::default();
 871        };
 872
 873        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
 874        let scroll_x = snapshot.scroll_position.x();
 875        let (fixed_blocks, non_fixed_blocks) = snapshot
 876            .blocks_in_range(rows.clone())
 877            .partition::<Vec<_>, _>(|(_, block)| match block {
 878                TransformBlock::ExcerptHeader { .. } => false,
 879                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
 880            });
 881        let mut render_block = |block: &TransformBlock, width: f32| {
 882            let mut element = match block {
 883                TransformBlock::Custom(block) => {
 884                    let align_to = block
 885                        .position()
 886                        .to_point(&snapshot.buffer_snapshot)
 887                        .to_display_point(snapshot);
 888                    let anchor_x = text_x
 889                        + if rows.contains(&align_to.row()) {
 890                            line_layouts[(align_to.row() - rows.start) as usize]
 891                                .x_for_index(align_to.column() as usize)
 892                        } else {
 893                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 894                                .x_for_index(align_to.column() as usize)
 895                        };
 896
 897                    cx.render(&editor, |_, cx| {
 898                        block.render(&mut BlockContext {
 899                            cx,
 900                            anchor_x,
 901                            gutter_padding,
 902                            line_height,
 903                            scroll_x,
 904                            gutter_width,
 905                            em_width,
 906                        })
 907                    })
 908                }
 909                TransformBlock::ExcerptHeader {
 910                    key,
 911                    buffer,
 912                    range,
 913                    starts_new_buffer,
 914                    ..
 915                } => {
 916                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
 917                        let jump_position = range
 918                            .primary
 919                            .as_ref()
 920                            .map_or(range.context.start, |primary| primary.start);
 921                        let jump_action = crate::Jump {
 922                            path: ProjectPath {
 923                                worktree_id: file.worktree_id(cx),
 924                                path: file.path.clone(),
 925                            },
 926                            position: language::ToPoint::to_point(&jump_position, buffer),
 927                            anchor: jump_position,
 928                        };
 929
 930                        enum JumpIcon {}
 931                        cx.render(&editor, |_, cx| {
 932                            MouseEventHandler::new::<JumpIcon, _, _>(*key, cx, |state, _| {
 933                                let style = style.jump_icon.style_for(state, false);
 934                                Svg::new("icons/jump.svg")
 935                                    .with_color(style.color)
 936                                    .constrained()
 937                                    .with_width(style.icon_width)
 938                                    .aligned()
 939                                    .contained()
 940                                    .with_style(style.container)
 941                                    .constrained()
 942                                    .with_width(style.button_width)
 943                                    .with_height(style.button_width)
 944                                    .boxed()
 945                            })
 946                            .with_cursor_style(CursorStyle::PointingHand)
 947                            .on_click(move |_, _, cx| cx.dispatch_action(jump_action.clone()))
 948                            .with_tooltip::<JumpIcon, _>(
 949                                *key,
 950                                "Jump to Buffer".to_string(),
 951                                Some(Box::new(crate::OpenExcerpts)),
 952                                tooltip_style.clone(),
 953                                cx,
 954                            )
 955                            .aligned()
 956                            .flex_float()
 957                            .boxed()
 958                        })
 959                    });
 960
 961                    if *starts_new_buffer {
 962                        let style = &self.style.diagnostic_path_header;
 963                        let font_size =
 964                            (style.text_scale_factor * self.style.text.font_size).round();
 965
 966                        let mut filename = None;
 967                        let mut parent_path = None;
 968                        if let Some(file) = buffer.file() {
 969                            let path = file.path();
 970                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
 971                            parent_path =
 972                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 973                        }
 974
 975                        Flex::row()
 976                            .with_child(
 977                                Label::new(
 978                                    filename.unwrap_or_else(|| "untitled".to_string()),
 979                                    style.filename.text.clone().with_font_size(font_size),
 980                                )
 981                                .contained()
 982                                .with_style(style.filename.container)
 983                                .aligned()
 984                                .boxed(),
 985                            )
 986                            .with_children(parent_path.map(|path| {
 987                                Label::new(path, style.path.text.clone().with_font_size(font_size))
 988                                    .contained()
 989                                    .with_style(style.path.container)
 990                                    .aligned()
 991                                    .boxed()
 992                            }))
 993                            .with_children(jump_icon)
 994                            .contained()
 995                            .with_style(style.container)
 996                            .with_padding_left(gutter_padding)
 997                            .with_padding_right(gutter_padding)
 998                            .expanded()
 999                            .named("path header block")
1000                    } else {
1001                        let text_style = self.style.text.clone();
1002                        Flex::row()
1003                            .with_child(Label::new("".to_string(), text_style).boxed())
1004                            .with_children(jump_icon)
1005                            .contained()
1006                            .with_padding_left(gutter_padding)
1007                            .with_padding_right(gutter_padding)
1008                            .expanded()
1009                            .named("collapsed context")
1010                    }
1011                }
1012            };
1013
1014            element.layout(
1015                SizeConstraint {
1016                    min: Vector2F::zero(),
1017                    max: vec2f(width, block.height() as f32 * line_height),
1018                },
1019                cx,
1020            );
1021            element
1022        };
1023
1024        let mut fixed_block_max_width = 0f32;
1025        let mut blocks = Vec::new();
1026        for (row, block) in fixed_blocks {
1027            let element = render_block(block, f32::INFINITY);
1028            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1029            blocks.push(BlockLayout {
1030                row,
1031                element,
1032                style: BlockStyle::Fixed,
1033            });
1034        }
1035        for (row, block) in non_fixed_blocks {
1036            let style = match block {
1037                TransformBlock::Custom(block) => block.style(),
1038                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1039            };
1040            let width = match style {
1041                BlockStyle::Sticky => editor_width,
1042                BlockStyle::Flex => editor_width
1043                    .max(fixed_block_max_width)
1044                    .max(gutter_width + scroll_width),
1045                BlockStyle::Fixed => unreachable!(),
1046            };
1047            let element = render_block(block, width);
1048            blocks.push(BlockLayout {
1049                row,
1050                element,
1051                style,
1052            });
1053        }
1054        (
1055            scroll_width.max(fixed_block_max_width - gutter_width),
1056            blocks,
1057        )
1058    }
1059}
1060
1061impl Element for EditorElement {
1062    type LayoutState = LayoutState;
1063    type PaintState = PaintState;
1064
1065    fn layout(
1066        &mut self,
1067        constraint: SizeConstraint,
1068        cx: &mut LayoutContext,
1069    ) -> (Vector2F, Self::LayoutState) {
1070        let mut size = constraint.max;
1071        if size.x().is_infinite() {
1072            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1073        }
1074
1075        let snapshot = self.snapshot(cx.app);
1076        let style = self.style.clone();
1077        let line_height = style.text.line_height(cx.font_cache);
1078
1079        let gutter_padding;
1080        let gutter_width;
1081        let gutter_margin;
1082        if snapshot.mode == EditorMode::Full {
1083            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
1084            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1085            gutter_margin = -style.text.descent(cx.font_cache);
1086        } else {
1087            gutter_padding = 0.0;
1088            gutter_width = 0.0;
1089            gutter_margin = 0.0;
1090        };
1091
1092        let text_width = size.x() - gutter_width;
1093        let em_width = style.text.em_width(cx.font_cache);
1094        let em_advance = style.text.em_advance(cx.font_cache);
1095        let overscroll = vec2f(em_width, 0.);
1096        let snapshot = self.update_view(cx.app, |view, cx| {
1097            let wrap_width = match view.soft_wrap_mode(cx) {
1098                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
1099                SoftWrap::EditorWidth => {
1100                    Some(text_width - gutter_margin - overscroll.x() - em_width)
1101                }
1102                SoftWrap::Column(column) => Some(column as f32 * em_advance),
1103            };
1104
1105            if view.set_wrap_width(wrap_width, cx) {
1106                view.snapshot(cx)
1107            } else {
1108                snapshot
1109            }
1110        });
1111
1112        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1113        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1114            size.set_y(
1115                scroll_height
1116                    .min(constraint.max_along(Axis::Vertical))
1117                    .max(constraint.min_along(Axis::Vertical))
1118                    .min(line_height * max_lines as f32),
1119            )
1120        } else if let EditorMode::SingleLine = snapshot.mode {
1121            size.set_y(
1122                line_height
1123                    .min(constraint.max_along(Axis::Vertical))
1124                    .max(constraint.min_along(Axis::Vertical)),
1125            )
1126        } else if size.y().is_infinite() {
1127            size.set_y(scroll_height);
1128        }
1129        let gutter_size = vec2f(gutter_width, size.y());
1130        let text_size = vec2f(text_width, size.y());
1131
1132        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
1133            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
1134            let snapshot = view.snapshot(cx);
1135            (autoscroll_horizontally, snapshot)
1136        });
1137
1138        let scroll_position = snapshot.scroll_position();
1139        let start_row = scroll_position.y() as u32;
1140        let scroll_top = scroll_position.y() * line_height;
1141
1142        // Add 1 to ensure selections bleed off screen
1143        let end_row = 1 + cmp::min(
1144            ((scroll_top + size.y()) / line_height).ceil() as u32,
1145            snapshot.max_point().row(),
1146        );
1147
1148        let start_anchor = if start_row == 0 {
1149            Anchor::min()
1150        } else {
1151            snapshot
1152                .buffer_snapshot
1153                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1154        };
1155        let end_anchor = if end_row > snapshot.max_point().row() {
1156            Anchor::max()
1157        } else {
1158            snapshot
1159                .buffer_snapshot
1160                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1161        };
1162
1163        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1164        let mut active_rows = BTreeMap::new();
1165        let mut highlighted_rows = None;
1166        let mut highlighted_ranges = Vec::new();
1167        self.update_view(cx.app, |view, cx| {
1168            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1169
1170            highlighted_rows = view.highlighted_rows();
1171            let theme = cx.global::<Settings>().theme.as_ref();
1172            highlighted_ranges = view.background_highlights_in_range(
1173                start_anchor.clone()..end_anchor.clone(),
1174                &display_map,
1175                theme,
1176            );
1177
1178            let mut remote_selections = HashMap::default();
1179            for (replica_id, line_mode, selection) in display_map
1180                .buffer_snapshot
1181                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1182            {
1183                // The local selections match the leader's selections.
1184                if Some(replica_id) == view.leader_replica_id {
1185                    continue;
1186                }
1187                remote_selections
1188                    .entry(replica_id)
1189                    .or_insert(Vec::new())
1190                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1191            }
1192            selections.extend(remote_selections);
1193
1194            if view.show_local_selections {
1195                let mut local_selections = view
1196                    .selections
1197                    .disjoint_in_range(start_anchor..end_anchor, cx);
1198                local_selections.extend(view.selections.pending(cx));
1199                for selection in &local_selections {
1200                    let is_empty = selection.start == selection.end;
1201                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1202                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1203                    for row in cmp::max(selection_start.row(), start_row)
1204                        ..=cmp::min(selection_end.row(), end_row)
1205                    {
1206                        let contains_non_empty_selection =
1207                            active_rows.entry(row).or_insert(!is_empty);
1208                        *contains_non_empty_selection |= !is_empty;
1209                    }
1210                }
1211
1212                // Render the local selections in the leader's color when following.
1213                let local_replica_id = view.leader_replica_id.unwrap_or(view.replica_id(cx));
1214
1215                selections.push((
1216                    local_replica_id,
1217                    local_selections
1218                        .into_iter()
1219                        .map(|selection| {
1220                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1221                        })
1222                        .collect(),
1223                ));
1224            }
1225        });
1226
1227        let line_number_layouts =
1228            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1229
1230        let mut max_visible_line_width = 0.0;
1231        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1232        for line in &line_layouts {
1233            if line.width() > max_visible_line_width {
1234                max_visible_line_width = line.width();
1235            }
1236        }
1237
1238        let style = self.style.clone();
1239        let longest_line_width = layout_line(
1240            snapshot.longest_row(),
1241            &snapshot,
1242            &style,
1243            cx.text_layout_cache,
1244        )
1245        .width();
1246        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1247        let em_width = style.text.em_width(cx.font_cache);
1248        let (scroll_width, blocks) = self.layout_blocks(
1249            start_row..end_row,
1250            &snapshot,
1251            size.x(),
1252            scroll_width,
1253            gutter_padding,
1254            gutter_width,
1255            em_width,
1256            gutter_width + gutter_margin,
1257            line_height,
1258            &style,
1259            &line_layouts,
1260            cx,
1261        );
1262
1263        let max_row = snapshot.max_point().row();
1264        let scroll_max = vec2f(
1265            ((scroll_width - text_size.x()) / em_width).max(0.0),
1266            max_row.saturating_sub(1) as f32,
1267        );
1268
1269        self.update_view(cx.app, |view, cx| {
1270            let clamped = view.clamp_scroll_left(scroll_max.x());
1271            let autoscrolled;
1272            if autoscroll_horizontally {
1273                autoscrolled = view.autoscroll_horizontally(
1274                    start_row,
1275                    text_size.x(),
1276                    scroll_width,
1277                    em_width,
1278                    &line_layouts,
1279                    cx,
1280                );
1281            } else {
1282                autoscrolled = false;
1283            }
1284
1285            if clamped || autoscrolled {
1286                snapshot = view.snapshot(cx);
1287            }
1288        });
1289
1290        let mut context_menu = None;
1291        let mut code_actions_indicator = None;
1292        let mut hover = None;
1293        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1294            let newest_selection_head = view
1295                .selections
1296                .newest::<usize>(cx)
1297                .head()
1298                .to_display_point(&snapshot);
1299
1300            let style = view.style(cx);
1301            if (start_row..end_row).contains(&newest_selection_head.row()) {
1302                if view.context_menu_visible() {
1303                    context_menu =
1304                        view.render_context_menu(newest_selection_head, style.clone(), cx);
1305                }
1306
1307                code_actions_indicator = view
1308                    .render_code_actions_indicator(&style, cx)
1309                    .map(|indicator| (newest_selection_head.row(), indicator));
1310            }
1311
1312            hover = view.hover_state.popover.clone().and_then(|hover| {
1313                let (point, rendered) = hover.render(&snapshot, style.clone(), cx);
1314                if point.row() >= snapshot.scroll_position().y() as u32 {
1315                    if line_layouts.len() > (point.row() - start_row) as usize {
1316                        return Some((point, rendered));
1317                    }
1318                }
1319
1320                None
1321            });
1322        });
1323
1324        if let Some((_, context_menu)) = context_menu.as_mut() {
1325            context_menu.layout(
1326                SizeConstraint {
1327                    min: Vector2F::zero(),
1328                    max: vec2f(
1329                        cx.window_size.x() * 0.7,
1330                        (12. * line_height).min((size.y() - line_height) / 2.),
1331                    ),
1332                },
1333                cx,
1334            );
1335        }
1336
1337        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1338            indicator.layout(
1339                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
1340                cx,
1341            );
1342        }
1343
1344        if let Some((_, hover)) = hover.as_mut() {
1345            hover.layout(
1346                SizeConstraint {
1347                    min: Vector2F::zero(),
1348                    max: vec2f(
1349                        (120. * em_width) // Default size
1350                            .min(size.x() / 2.) // Shrink to half of the editor width
1351                            .max(20. * em_width), // Apply minimum width of 20 characters
1352                        (16. * line_height) // Default size
1353                            .min(size.y() / 2.) // Shrink to half of the editor height
1354                            .max(4. * line_height), // Apply minimum height of 4 lines
1355                    ),
1356                },
1357                cx,
1358            );
1359        }
1360
1361        (
1362            size,
1363            LayoutState {
1364                size,
1365                scroll_max,
1366                gutter_size,
1367                gutter_padding,
1368                text_size,
1369                gutter_margin,
1370                snapshot,
1371                active_rows,
1372                highlighted_rows,
1373                highlighted_ranges,
1374                line_layouts,
1375                line_number_layouts,
1376                blocks,
1377                line_height,
1378                em_width,
1379                em_advance,
1380                selections,
1381                context_menu,
1382                code_actions_indicator,
1383                hover,
1384            },
1385        )
1386    }
1387
1388    fn paint(
1389        &mut self,
1390        bounds: RectF,
1391        visible_bounds: RectF,
1392        layout: &mut Self::LayoutState,
1393        cx: &mut PaintContext,
1394    ) -> Self::PaintState {
1395        cx.scene.push_layer(Some(bounds));
1396
1397        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1398        let text_bounds = RectF::new(
1399            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1400            layout.text_size,
1401        );
1402
1403        let mut paint_state = PaintState {
1404            bounds,
1405            gutter_bounds,
1406            text_bounds,
1407            context_menu_bounds: None,
1408            hover_bounds: None,
1409        };
1410
1411        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1412        if layout.gutter_size.x() > 0. {
1413            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1414        }
1415        self.paint_text(text_bounds, visible_bounds, layout, &mut paint_state, cx);
1416
1417        if !layout.blocks.is_empty() {
1418            cx.scene.push_layer(Some(bounds));
1419            self.paint_blocks(bounds, visible_bounds, layout, cx);
1420            cx.scene.pop_layer();
1421        }
1422
1423        cx.scene.pop_layer();
1424
1425        paint_state
1426    }
1427
1428    fn dispatch_event(
1429        &mut self,
1430        event: &Event,
1431        _: RectF,
1432        _: RectF,
1433        layout: &mut LayoutState,
1434        paint: &mut PaintState,
1435        cx: &mut EventContext,
1436    ) -> bool {
1437        if let Some((_, context_menu)) = &mut layout.context_menu {
1438            if context_menu.dispatch_event(event, cx) {
1439                return true;
1440            }
1441        }
1442
1443        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1444            if indicator.dispatch_event(event, cx) {
1445                return true;
1446            }
1447        }
1448
1449        if let Some((_, hover)) = &mut layout.hover {
1450            if hover.dispatch_event(event, cx) {
1451                return true;
1452            }
1453        }
1454
1455        for block in &mut layout.blocks {
1456            if block.element.dispatch_event(event, cx) {
1457                return true;
1458            }
1459        }
1460
1461        match event {
1462            Event::LeftMouseDown {
1463                position,
1464                cmd,
1465                alt,
1466                shift,
1467                click_count,
1468                ..
1469            } => self.mouse_down(
1470                *position,
1471                *cmd,
1472                *alt,
1473                *shift,
1474                *click_count,
1475                layout,
1476                paint,
1477                cx,
1478            ),
1479            Event::LeftMouseUp { position, .. } => self.mouse_up(*position, cx),
1480            Event::LeftMouseDragged { position, .. } => {
1481                self.mouse_dragged(*position, layout, paint, cx)
1482            }
1483            Event::ScrollWheel {
1484                position,
1485                delta,
1486                precise,
1487            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1488            Event::KeyDown { input, .. } => self.key_down(input.as_deref(), cx),
1489            Event::ModifiersChanged { cmd, .. } => self.modifiers_changed(*cmd, cx),
1490            Event::MouseMoved { position, cmd, .. } => {
1491                self.mouse_moved(*position, *cmd, layout, paint, cx)
1492            }
1493
1494            _ => false,
1495        }
1496    }
1497
1498    fn debug(
1499        &self,
1500        bounds: RectF,
1501        _: &Self::LayoutState,
1502        _: &Self::PaintState,
1503        _: &gpui::DebugContext,
1504    ) -> json::Value {
1505        json!({
1506            "type": "BufferElement",
1507            "bounds": bounds.to_json()
1508        })
1509    }
1510}
1511
1512pub struct LayoutState {
1513    size: Vector2F,
1514    scroll_max: Vector2F,
1515    gutter_size: Vector2F,
1516    gutter_padding: f32,
1517    gutter_margin: f32,
1518    text_size: Vector2F,
1519    snapshot: EditorSnapshot,
1520    active_rows: BTreeMap<u32, bool>,
1521    highlighted_rows: Option<Range<u32>>,
1522    line_layouts: Vec<text_layout::Line>,
1523    line_number_layouts: Vec<Option<text_layout::Line>>,
1524    blocks: Vec<BlockLayout>,
1525    line_height: f32,
1526    em_width: f32,
1527    em_advance: f32,
1528    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1529    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1530    context_menu: Option<(DisplayPoint, ElementBox)>,
1531    code_actions_indicator: Option<(u32, ElementBox)>,
1532    hover: Option<(DisplayPoint, ElementBox)>,
1533}
1534
1535struct BlockLayout {
1536    row: u32,
1537    element: ElementBox,
1538    style: BlockStyle,
1539}
1540
1541fn layout_line(
1542    row: u32,
1543    snapshot: &EditorSnapshot,
1544    style: &EditorStyle,
1545    layout_cache: &TextLayoutCache,
1546) -> text_layout::Line {
1547    let mut line = snapshot.line(row);
1548
1549    if line.len() > MAX_LINE_LEN {
1550        let mut len = MAX_LINE_LEN;
1551        while !line.is_char_boundary(len) {
1552            len -= 1;
1553        }
1554
1555        line.truncate(len);
1556    }
1557
1558    layout_cache.layout_str(
1559        &line,
1560        style.text.font_size,
1561        &[(
1562            snapshot.line_len(row) as usize,
1563            RunStyle {
1564                font_id: style.text.font_id,
1565                color: Color::black(),
1566                underline: Default::default(),
1567            },
1568        )],
1569    )
1570}
1571
1572pub struct PaintState {
1573    bounds: RectF,
1574    gutter_bounds: RectF,
1575    text_bounds: RectF,
1576    context_menu_bounds: Option<RectF>,
1577    hover_bounds: Option<RectF>,
1578}
1579
1580impl PaintState {
1581    /// Returns two display points. The first is the nearest valid
1582    /// position in the current buffer and the second is the distance to the
1583    /// nearest valid position if there was overshoot.
1584    fn point_for_position(
1585        &self,
1586        snapshot: &EditorSnapshot,
1587        layout: &LayoutState,
1588        position: Vector2F,
1589    ) -> (DisplayPoint, DisplayPoint) {
1590        let scroll_position = snapshot.scroll_position();
1591        let position = position - self.text_bounds.origin();
1592        let y = position.y().max(0.0).min(layout.size.y());
1593        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1594        let row_overshoot = row.saturating_sub(snapshot.max_point().row());
1595        let row = cmp::min(row, snapshot.max_point().row());
1596        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1597        let x = position.x() + (scroll_position.x() * layout.em_width);
1598
1599        let column = if x >= 0.0 {
1600            line.index_for_x(x)
1601                .map(|ix| ix as u32)
1602                .unwrap_or_else(|| snapshot.line_len(row))
1603        } else {
1604            0
1605        };
1606        let column_overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1607
1608        (
1609            DisplayPoint::new(row, column),
1610            DisplayPoint::new(row_overshoot, column_overshoot),
1611        )
1612    }
1613}
1614
1615#[derive(Copy, Clone, PartialEq, Eq)]
1616pub enum CursorShape {
1617    Bar,
1618    Block,
1619    Underscore,
1620}
1621
1622impl Default for CursorShape {
1623    fn default() -> Self {
1624        CursorShape::Bar
1625    }
1626}
1627
1628struct Cursor {
1629    origin: Vector2F,
1630    block_width: f32,
1631    line_height: f32,
1632    color: Color,
1633    shape: CursorShape,
1634    block_text: Option<Line>,
1635}
1636
1637impl Cursor {
1638    fn paint(&self, cx: &mut PaintContext) {
1639        let bounds = match self.shape {
1640            CursorShape::Bar => RectF::new(self.origin, vec2f(2.0, self.line_height)),
1641            CursorShape::Block => {
1642                RectF::new(self.origin, vec2f(self.block_width, self.line_height))
1643            }
1644            CursorShape::Underscore => RectF::new(
1645                self.origin + Vector2F::new(0.0, self.line_height - 2.0),
1646                vec2f(self.block_width, 2.0),
1647            ),
1648        };
1649
1650        cx.scene.push_quad(Quad {
1651            bounds,
1652            background: Some(self.color),
1653            border: Border::new(0., Color::black()),
1654            corner_radius: 0.,
1655        });
1656
1657        if let Some(block_text) = &self.block_text {
1658            block_text.paint(self.origin, bounds, self.line_height, cx);
1659        }
1660    }
1661}
1662
1663#[derive(Debug)]
1664struct HighlightedRange {
1665    start_y: f32,
1666    line_height: f32,
1667    lines: Vec<HighlightedRangeLine>,
1668    color: Color,
1669    corner_radius: f32,
1670}
1671
1672#[derive(Debug)]
1673struct HighlightedRangeLine {
1674    start_x: f32,
1675    end_x: f32,
1676}
1677
1678impl HighlightedRange {
1679    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1680        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1681            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1682            self.paint_lines(
1683                self.start_y + self.line_height,
1684                &self.lines[1..],
1685                bounds,
1686                scene,
1687            );
1688        } else {
1689            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1690        }
1691    }
1692
1693    fn paint_lines(
1694        &self,
1695        start_y: f32,
1696        lines: &[HighlightedRangeLine],
1697        bounds: RectF,
1698        scene: &mut Scene,
1699    ) {
1700        if lines.is_empty() {
1701            return;
1702        }
1703
1704        let mut path = PathBuilder::new();
1705        let first_line = lines.first().unwrap();
1706        let last_line = lines.last().unwrap();
1707
1708        let first_top_left = vec2f(first_line.start_x, start_y);
1709        let first_top_right = vec2f(first_line.end_x, start_y);
1710
1711        let curve_height = vec2f(0., self.corner_radius);
1712        let curve_width = |start_x: f32, end_x: f32| {
1713            let max = (end_x - start_x) / 2.;
1714            let width = if max < self.corner_radius {
1715                max
1716            } else {
1717                self.corner_radius
1718            };
1719
1720            vec2f(width, 0.)
1721        };
1722
1723        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1724        path.reset(first_top_right - top_curve_width);
1725        path.curve_to(first_top_right + curve_height, first_top_right);
1726
1727        let mut iter = lines.iter().enumerate().peekable();
1728        while let Some((ix, line)) = iter.next() {
1729            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1730
1731            if let Some((_, next_line)) = iter.peek() {
1732                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1733
1734                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1735                    Ordering::Equal => {
1736                        path.line_to(bottom_right);
1737                    }
1738                    Ordering::Less => {
1739                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1740                        path.line_to(bottom_right - curve_height);
1741                        if self.corner_radius > 0. {
1742                            path.curve_to(bottom_right - curve_width, bottom_right);
1743                        }
1744                        path.line_to(next_top_right + curve_width);
1745                        if self.corner_radius > 0. {
1746                            path.curve_to(next_top_right + curve_height, next_top_right);
1747                        }
1748                    }
1749                    Ordering::Greater => {
1750                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1751                        path.line_to(bottom_right - curve_height);
1752                        if self.corner_radius > 0. {
1753                            path.curve_to(bottom_right + curve_width, bottom_right);
1754                        }
1755                        path.line_to(next_top_right - curve_width);
1756                        if self.corner_radius > 0. {
1757                            path.curve_to(next_top_right + curve_height, next_top_right);
1758                        }
1759                    }
1760                }
1761            } else {
1762                let curve_width = curve_width(line.start_x, line.end_x);
1763                path.line_to(bottom_right - curve_height);
1764                if self.corner_radius > 0. {
1765                    path.curve_to(bottom_right - curve_width, bottom_right);
1766                }
1767
1768                let bottom_left = vec2f(line.start_x, bottom_right.y());
1769                path.line_to(bottom_left + curve_width);
1770                if self.corner_radius > 0. {
1771                    path.curve_to(bottom_left - curve_height, bottom_left);
1772                }
1773            }
1774        }
1775
1776        if first_line.start_x > last_line.start_x {
1777            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1778            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1779            path.line_to(second_top_left + curve_height);
1780            if self.corner_radius > 0. {
1781                path.curve_to(second_top_left + curve_width, second_top_left);
1782            }
1783            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1784            path.line_to(first_bottom_left - curve_width);
1785            if self.corner_radius > 0. {
1786                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1787            }
1788        }
1789
1790        path.line_to(first_top_left + curve_height);
1791        if self.corner_radius > 0. {
1792            path.curve_to(first_top_left + top_curve_width, first_top_left);
1793        }
1794        path.line_to(first_top_right - top_curve_width);
1795
1796        scene.push_path(path.build(self.color, Some(bounds)));
1797    }
1798}
1799
1800fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1801    delta.powf(1.5) / 100.0
1802}
1803
1804fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1805    delta.powf(1.2) / 300.0
1806}
1807
1808#[cfg(test)]
1809mod tests {
1810    use std::sync::Arc;
1811
1812    use super::*;
1813    use crate::{
1814        display_map::{BlockDisposition, BlockProperties},
1815        Editor, MultiBuffer,
1816    };
1817    use settings::Settings;
1818    use util::test::sample_text;
1819
1820    #[gpui::test]
1821    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1822        cx.set_global(Settings::test(cx));
1823        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1824        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1825            Editor::new(EditorMode::Full, buffer, None, None, cx)
1826        });
1827        let element = EditorElement::new(
1828            editor.downgrade(),
1829            editor.read(cx).style(cx),
1830            CursorShape::Bar,
1831        );
1832
1833        let layouts = editor.update(cx, |editor, cx| {
1834            let snapshot = editor.snapshot(cx);
1835            let mut presenter = cx.build_presenter(window_id, 30.);
1836            let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1837            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1838        });
1839        assert_eq!(layouts.len(), 6);
1840    }
1841
1842    #[gpui::test]
1843    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
1844        cx.set_global(Settings::test(cx));
1845        let buffer = MultiBuffer::build_simple("", cx);
1846        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1847            Editor::new(EditorMode::Full, buffer, None, None, cx)
1848        });
1849
1850        editor.update(cx, |editor, cx| {
1851            editor.set_placeholder_text("hello", cx);
1852            editor.insert_blocks(
1853                [BlockProperties {
1854                    style: BlockStyle::Fixed,
1855                    disposition: BlockDisposition::Above,
1856                    height: 3,
1857                    position: Anchor::min(),
1858                    render: Arc::new(|_| Empty::new().boxed()),
1859                }],
1860                cx,
1861            );
1862
1863            // Blur the editor so that it displays placeholder text.
1864            cx.blur();
1865        });
1866
1867        let mut element = EditorElement::new(
1868            editor.downgrade(),
1869            editor.read(cx).style(cx),
1870            CursorShape::Bar,
1871        );
1872
1873        let mut scene = Scene::new(1.0);
1874        let mut presenter = cx.build_presenter(window_id, 30.);
1875        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1876        let (size, mut state) = element.layout(
1877            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
1878            &mut layout_cx,
1879        );
1880
1881        assert_eq!(state.line_layouts.len(), 4);
1882        assert_eq!(
1883            state
1884                .line_number_layouts
1885                .iter()
1886                .map(Option::is_some)
1887                .collect::<Vec<_>>(),
1888            &[false, false, false, true]
1889        );
1890
1891        // Don't panic.
1892        let bounds = RectF::new(Default::default(), size);
1893        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
1894        element.paint(bounds, bounds, &mut state, &mut paint_cx);
1895    }
1896}