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