element.rs

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