element.rs

   1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSnapshot, Input, Scroll, Select, SelectPhase,
   4    SoftWrap, ToPoint, MAX_LINE_LEN,
   5};
   6use crate::{
   7    display_map::{BlockStyle, DisplaySnapshot, TransformBlock},
   8    hover_popover::HoverAt,
   9    link_go_to_definition::{CmdChanged, GoToFetchedDefinition, UpdateGoToDefinitionLink},
  10    EditorStyle,
  11};
  12use clock::ReplicaId;
  13use collections::{BTreeMap, HashMap};
  14use gpui::{
  15    color::Color,
  16    elements::*,
  17    fonts::{HighlightStyle, Underline},
  18    geometry::{
  19        rect::RectF,
  20        vector::{vec2f, Vector2F},
  21        PathBuilder,
  22    },
  23    json::{self, ToJson},
  24    platform::CursorStyle,
  25    text_layout::{self, Line, RunStyle, TextLayoutCache},
  26    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext, KeyDownEvent,
  27    LayoutContext, ModifiersChangedEvent, MouseButton, MouseEvent, MouseMovedEvent,
  28    MutableAppContext, PaintContext, Quad, Scene, ScrollWheelEvent, SizeConstraint, ViewContext,
  29    WeakViewHandle,
  30};
  31use json::json;
  32use language::{Bias, DiagnosticSeverity, Selection};
  33use project::ProjectPath;
  34use settings::Settings;
  35use smallvec::SmallVec;
  36use std::{
  37    cmp::{self, Ordering},
  38    fmt::Write,
  39    iter,
  40    ops::Range,
  41};
  42
  43struct SelectionLayout {
  44    head: DisplayPoint,
  45    range: Range<DisplayPoint>,
  46}
  47
  48impl SelectionLayout {
  49    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  50        selection: Selection<T>,
  51        line_mode: bool,
  52        map: &DisplaySnapshot,
  53    ) -> Self {
  54        if line_mode {
  55            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  56            let point_range = map.expand_to_line(selection.range());
  57            Self {
  58                head: selection.head().to_display_point(map),
  59                range: point_range.start.to_display_point(map)
  60                    ..point_range.end.to_display_point(map),
  61            }
  62        } else {
  63            let selection = selection.map(|p| p.to_display_point(map));
  64            Self {
  65                head: selection.head(),
  66                range: selection.range(),
  67            }
  68        }
  69    }
  70}
  71
  72pub struct EditorElement {
  73    view: WeakViewHandle<Editor>,
  74    style: EditorStyle,
  75    cursor_shape: CursorShape,
  76}
  77
  78impl EditorElement {
  79    pub fn new(
  80        view: WeakViewHandle<Editor>,
  81        style: EditorStyle,
  82        cursor_shape: CursorShape,
  83    ) -> Self {
  84        Self {
  85            view,
  86            style,
  87            cursor_shape,
  88        }
  89    }
  90
  91    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  92        self.view.upgrade(cx).unwrap().read(cx)
  93    }
  94
  95    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
  96    where
  97        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
  98    {
  99        self.view.upgrade(cx).unwrap().update(cx, f)
 100    }
 101
 102    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
 103        self.update_view(cx, |view, cx| view.snapshot(cx))
 104    }
 105
 106    fn mouse_down(
 107        &self,
 108        position: Vector2F,
 109        cmd: bool,
 110        alt: bool,
 111        shift: bool,
 112        mut click_count: usize,
 113        layout: &mut LayoutState,
 114        paint: &mut PaintState,
 115        cx: &mut EventContext,
 116    ) -> bool {
 117        if cmd && paint.text_bounds.contains_point(position) {
 118            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 119            if overshoot.is_zero() {
 120                cx.dispatch_action(GoToFetchedDefinition { point });
 121                return true;
 122            }
 123        }
 124
 125        if paint.gutter_bounds.contains_point(position) {
 126            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 127        } else if !paint.text_bounds.contains_point(position) {
 128            return false;
 129        }
 130
 131        let snapshot = self.snapshot(cx.app);
 132        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 133
 134        if shift && alt {
 135            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 136                position,
 137                overshoot: overshoot.column(),
 138            }));
 139        } else if shift {
 140            cx.dispatch_action(Select(SelectPhase::Extend {
 141                position,
 142                click_count,
 143            }));
 144        } else {
 145            cx.dispatch_action(Select(SelectPhase::Begin {
 146                position,
 147                add: alt,
 148                click_count,
 149            }));
 150        }
 151
 152        true
 153    }
 154
 155    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
 156        if self.view(cx.app.as_ref()).is_selecting() {
 157            cx.dispatch_action(Select(SelectPhase::End));
 158            true
 159        } else {
 160            false
 161        }
 162    }
 163
 164    fn mouse_dragged(
 165        &self,
 166        position: Vector2F,
 167        layout: &mut LayoutState,
 168        paint: &mut PaintState,
 169        cx: &mut EventContext,
 170    ) -> bool {
 171        let view = self.view(cx.app.as_ref());
 172
 173        if view.is_selecting() {
 174            let rect = paint.text_bounds;
 175            let mut scroll_delta = Vector2F::zero();
 176
 177            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 178            let top = rect.origin_y() + vertical_margin;
 179            let bottom = rect.lower_left().y() - vertical_margin;
 180            if position.y() < top {
 181                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 182            }
 183            if position.y() > bottom {
 184                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 185            }
 186
 187            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 188            let left = rect.origin_x() + horizontal_margin;
 189            let right = rect.upper_right().x() - horizontal_margin;
 190            if position.x() < left {
 191                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 192                    left - position.x(),
 193                ))
 194            }
 195            if position.x() > right {
 196                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 197                    position.x() - right,
 198                ))
 199            }
 200
 201            let snapshot = self.snapshot(cx.app);
 202            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 203
 204            cx.dispatch_action(Select(SelectPhase::Update {
 205                position,
 206                overshoot: overshoot.column(),
 207                scroll_position: (snapshot.scroll_position() + scroll_delta)
 208                    .clamp(Vector2F::zero(), layout.scroll_max),
 209            }));
 210            true
 211        } else {
 212            false
 213        }
 214    }
 215
 216    fn mouse_moved(
 217        &self,
 218        position: Vector2F,
 219        cmd: bool,
 220        layout: &LayoutState,
 221        paint: &PaintState,
 222        cx: &mut EventContext,
 223    ) -> bool {
 224        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 225        // Don't trigger hover popover if mouse is hovering over context menu
 226        let point = if paint.text_bounds.contains_point(position) {
 227            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 228            if overshoot.is_zero() {
 229                Some(point)
 230            } else {
 231                None
 232            }
 233        } else {
 234            None
 235        };
 236
 237        cx.dispatch_action(UpdateGoToDefinitionLink {
 238            point,
 239            cmd_held: cmd,
 240        });
 241
 242        if paint
 243            .context_menu_bounds
 244            .map_or(false, |context_menu_bounds| {
 245                context_menu_bounds.contains_point(position)
 246            })
 247        {
 248            return false;
 249        }
 250
 251        if paint
 252            .hover_bounds
 253            .map_or(false, |hover_bounds| hover_bounds.contains_point(position))
 254        {
 255            return false;
 256        }
 257
 258        cx.dispatch_action(HoverAt { point });
 259        true
 260    }
 261
 262    fn key_down(&self, input: Option<&str>, cx: &mut EventContext) -> bool {
 263        let view = self.view.upgrade(cx.app).unwrap();
 264
 265        if view.is_focused(cx.app) {
 266            if let Some(input) = input {
 267                cx.dispatch_action(Input(input.to_string()));
 268                true
 269            } else {
 270                false
 271            }
 272        } else {
 273            false
 274        }
 275    }
 276
 277    fn modifiers_changed(&self, cmd: bool, cx: &mut EventContext) -> bool {
 278        cx.dispatch_action(CmdChanged { cmd_down: cmd });
 279        false
 280    }
 281
 282    fn scroll(
 283        &self,
 284        position: Vector2F,
 285        mut delta: Vector2F,
 286        precise: bool,
 287        layout: &mut LayoutState,
 288        paint: &mut PaintState,
 289        cx: &mut EventContext,
 290    ) -> bool {
 291        if !paint.bounds.contains_point(position) {
 292            return false;
 293        }
 294
 295        let snapshot = self.snapshot(cx.app);
 296        let max_glyph_width = layout.em_width;
 297        if !precise {
 298            delta *= vec2f(max_glyph_width, layout.line_height);
 299        }
 300
 301        let scroll_position = snapshot.scroll_position();
 302        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 303        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 304        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 305
 306        cx.dispatch_action(Scroll(scroll_position));
 307
 308        true
 309    }
 310
 311    fn paint_background(
 312        &self,
 313        gutter_bounds: RectF,
 314        text_bounds: RectF,
 315        layout: &LayoutState,
 316        cx: &mut PaintContext,
 317    ) {
 318        let bounds = gutter_bounds.union_rect(text_bounds);
 319        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 320        let editor = self.view(cx.app);
 321        cx.scene.push_quad(Quad {
 322            bounds: gutter_bounds,
 323            background: Some(self.style.gutter_background),
 324            border: Border::new(0., Color::transparent_black()),
 325            corner_radius: 0.,
 326        });
 327        cx.scene.push_quad(Quad {
 328            bounds: text_bounds,
 329            background: Some(self.style.background),
 330            border: Border::new(0., Color::transparent_black()),
 331            corner_radius: 0.,
 332        });
 333
 334        if let EditorMode::Full = editor.mode {
 335            let mut active_rows = layout.active_rows.iter().peekable();
 336            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 337                let mut end_row = *start_row;
 338                while active_rows.peek().map_or(false, |r| {
 339                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 340                }) {
 341                    active_rows.next().unwrap();
 342                    end_row += 1;
 343                }
 344
 345                if !contains_non_empty_selection {
 346                    let origin = vec2f(
 347                        bounds.origin_x(),
 348                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 349                    );
 350                    let size = vec2f(
 351                        bounds.width(),
 352                        layout.line_height * (end_row - start_row + 1) as f32,
 353                    );
 354                    cx.scene.push_quad(Quad {
 355                        bounds: RectF::new(origin, size),
 356                        background: Some(self.style.active_line_background),
 357                        border: Border::default(),
 358                        corner_radius: 0.,
 359                    });
 360                }
 361            }
 362
 363            if let Some(highlighted_rows) = &layout.highlighted_rows {
 364                let origin = vec2f(
 365                    bounds.origin_x(),
 366                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 367                        - scroll_top,
 368                );
 369                let size = vec2f(
 370                    bounds.width(),
 371                    layout.line_height * highlighted_rows.len() as f32,
 372                );
 373                cx.scene.push_quad(Quad {
 374                    bounds: RectF::new(origin, size),
 375                    background: Some(self.style.highlighted_line_background),
 376                    border: Border::default(),
 377                    corner_radius: 0.,
 378                });
 379            }
 380        }
 381    }
 382
 383    fn paint_gutter(
 384        &mut self,
 385        bounds: RectF,
 386        visible_bounds: RectF,
 387        layout: &mut LayoutState,
 388        cx: &mut PaintContext,
 389    ) {
 390        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 391        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 392            if let Some(line) = line {
 393                let line_origin = bounds.origin()
 394                    + vec2f(
 395                        bounds.width() - line.width() - layout.gutter_padding,
 396                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 397                    );
 398                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 399            }
 400        }
 401
 402        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 403            let mut x = bounds.width() - layout.gutter_padding;
 404            let mut y = *row as f32 * layout.line_height - scroll_top;
 405            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 406            y += (layout.line_height - indicator.size().y()) / 2.;
 407            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 408        }
 409    }
 410
 411    fn paint_text(
 412        &mut self,
 413        bounds: RectF,
 414        visible_bounds: RectF,
 415        layout: &mut LayoutState,
 416        paint: &mut PaintState,
 417        cx: &mut PaintContext,
 418    ) {
 419        let view = self.view(cx.app);
 420        let style = &self.style;
 421        let local_replica_id = view.replica_id(cx);
 422        let scroll_position = layout.snapshot.scroll_position();
 423        let start_row = scroll_position.y() as u32;
 424        let scroll_top = scroll_position.y() * layout.line_height;
 425        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 426        let max_glyph_width = layout.em_width;
 427        let scroll_left = scroll_position.x() * max_glyph_width;
 428        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 429
 430        cx.scene.push_layer(Some(bounds));
 431
 432        cx.scene.push_cursor_region(CursorRegion {
 433            bounds,
 434            style: if !view.link_go_to_definition_state.definitions.is_empty() {
 435                CursorStyle::PointingHand
 436            } else {
 437                CursorStyle::IBeam
 438            },
 439        });
 440
 441        for (range, color) in &layout.highlighted_ranges {
 442            self.paint_highlighted_range(
 443                range.clone(),
 444                start_row,
 445                end_row,
 446                *color,
 447                0.,
 448                0.15 * layout.line_height,
 449                layout,
 450                content_origin,
 451                scroll_top,
 452                scroll_left,
 453                bounds,
 454                cx,
 455            );
 456        }
 457
 458        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 459        for (replica_id, selections) in &layout.selections {
 460            let selection_style = style.replica_selection_style(*replica_id);
 461            let corner_radius = 0.15 * layout.line_height;
 462
 463            for selection in selections {
 464                self.paint_highlighted_range(
 465                    selection.range.clone(),
 466                    start_row,
 467                    end_row,
 468                    selection_style.selection,
 469                    corner_radius,
 470                    corner_radius * 2.,
 471                    layout,
 472                    content_origin,
 473                    scroll_top,
 474                    scroll_left,
 475                    bounds,
 476                    cx,
 477                );
 478
 479                if view.show_local_cursors() || *replica_id != local_replica_id {
 480                    let cursor_position = selection.head;
 481                    if (start_row..end_row).contains(&cursor_position.row()) {
 482                        let cursor_row_layout =
 483                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 484                        let cursor_column = cursor_position.column() as usize;
 485
 486                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 487                        let mut block_width =
 488                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 489                        if block_width == 0.0 {
 490                            block_width = layout.em_width;
 491                        }
 492
 493                        let block_text =
 494                            if let CursorShape::Block = self.cursor_shape {
 495                                layout.snapshot.chars_at(cursor_position).next().and_then(
 496                                    |character| {
 497                                        let font_id =
 498                                            cursor_row_layout.font_for_index(cursor_column)?;
 499                                        let text = character.to_string();
 500
 501                                        Some(cx.text_layout_cache.layout_str(
 502                                            &text,
 503                                            cursor_row_layout.font_size(),
 504                                            &[(
 505                                                text.len(),
 506                                                RunStyle {
 507                                                    font_id,
 508                                                    color: style.background,
 509                                                    underline: Default::default(),
 510                                                },
 511                                            )],
 512                                        ))
 513                                    },
 514                                )
 515                            } else {
 516                                None
 517                            };
 518
 519                        let x = cursor_character_x - scroll_left;
 520                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 521                        cursors.push(Cursor {
 522                            color: selection_style.cursor,
 523                            block_width,
 524                            origin: vec2f(x, y),
 525                            line_height: layout.line_height,
 526                            shape: self.cursor_shape,
 527                            block_text,
 528                        });
 529                    }
 530                }
 531            }
 532        }
 533
 534        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 535            // Draw glyphs
 536            for (ix, line) in layout.line_layouts.iter().enumerate() {
 537                let row = start_row + ix as u32;
 538                line.paint(
 539                    content_origin
 540                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 541                    visible_text_bounds,
 542                    layout.line_height,
 543                    cx,
 544                );
 545            }
 546        }
 547
 548        cx.scene.push_layer(Some(bounds));
 549        for cursor in cursors {
 550            cursor.paint(content_origin, cx);
 551        }
 552        cx.scene.pop_layer();
 553
 554        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 555            cx.scene.push_stacking_context(None);
 556            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 557            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 558            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 559            let mut list_origin = content_origin + vec2f(x, y);
 560            let list_width = context_menu.size().x();
 561            let list_height = context_menu.size().y();
 562
 563            // Snap the right edge of the list to the right edge of the window if
 564            // its horizontal bounds overflow.
 565            if list_origin.x() + list_width > cx.window_size.x() {
 566                list_origin.set_x((cx.window_size.x() - list_width).max(0.));
 567            }
 568
 569            if list_origin.y() + list_height > bounds.max_y() {
 570                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 571            }
 572
 573            context_menu.paint(
 574                list_origin,
 575                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 576                cx,
 577            );
 578
 579            paint.context_menu_bounds = Some(RectF::new(list_origin, context_menu.size()));
 580
 581            cx.scene.pop_stacking_context();
 582        }
 583
 584        if let Some((position, hover_popover)) = layout.hover.as_mut() {
 585            cx.scene.push_stacking_context(None);
 586
 587            // This is safe because we check on layout whether the required row is available
 588            let hovered_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 589            let size = hover_popover.size();
 590            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 591            let y = position.row() as f32 * layout.line_height - scroll_top - size.y();
 592            let mut popover_origin = content_origin + vec2f(x, y);
 593
 594            if popover_origin.y() < 0.0 {
 595                popover_origin.set_y(popover_origin.y() + layout.line_height + size.y());
 596            }
 597
 598            let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 599            if x_out_of_bounds < 0.0 {
 600                popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 601            }
 602
 603            hover_popover.paint(
 604                popover_origin,
 605                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 606                cx,
 607            );
 608
 609            paint.hover_bounds = Some(
 610                RectF::new(popover_origin, hover_popover.size()).dilate(Vector2F::new(0., 5.)),
 611            );
 612
 613            cx.scene.pop_stacking_context();
 614        }
 615
 616        cx.scene.pop_layer();
 617    }
 618
 619    fn paint_highlighted_range(
 620        &self,
 621        range: Range<DisplayPoint>,
 622        start_row: u32,
 623        end_row: u32,
 624        color: Color,
 625        corner_radius: f32,
 626        line_end_overshoot: f32,
 627        layout: &LayoutState,
 628        content_origin: Vector2F,
 629        scroll_top: f32,
 630        scroll_left: f32,
 631        bounds: RectF,
 632        cx: &mut PaintContext,
 633    ) {
 634        if range.start != range.end {
 635            let row_range = if range.end.column() == 0 {
 636                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 637            } else {
 638                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 639            };
 640
 641            let highlighted_range = HighlightedRange {
 642                color,
 643                line_height: layout.line_height,
 644                corner_radius,
 645                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 646                    - scroll_top,
 647                lines: row_range
 648                    .into_iter()
 649                    .map(|row| {
 650                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 651                        HighlightedRangeLine {
 652                            start_x: if row == range.start.row() {
 653                                content_origin.x()
 654                                    + line_layout.x_for_index(range.start.column() as usize)
 655                                    - scroll_left
 656                            } else {
 657                                content_origin.x() - scroll_left
 658                            },
 659                            end_x: if row == range.end.row() {
 660                                content_origin.x()
 661                                    + line_layout.x_for_index(range.end.column() as usize)
 662                                    - scroll_left
 663                            } else {
 664                                content_origin.x() + line_layout.width() + line_end_overshoot
 665                                    - scroll_left
 666                            },
 667                        }
 668                    })
 669                    .collect(),
 670            };
 671
 672            highlighted_range.paint(bounds, cx.scene);
 673        }
 674    }
 675
 676    fn paint_blocks(
 677        &mut self,
 678        bounds: RectF,
 679        visible_bounds: RectF,
 680        layout: &mut LayoutState,
 681        cx: &mut PaintContext,
 682    ) {
 683        let scroll_position = layout.snapshot.scroll_position();
 684        let scroll_left = scroll_position.x() * layout.em_width;
 685        let scroll_top = scroll_position.y() * layout.line_height;
 686
 687        for block in &mut layout.blocks {
 688            let mut origin =
 689                bounds.origin() + vec2f(0., block.row as f32 * layout.line_height - scroll_top);
 690            if !matches!(block.style, BlockStyle::Sticky) {
 691                origin += vec2f(-scroll_left, 0.);
 692            }
 693            block.element.paint(origin, visible_bounds, cx);
 694        }
 695    }
 696
 697    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 698        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 699        let style = &self.style;
 700
 701        cx.text_layout_cache
 702            .layout_str(
 703                "1".repeat(digit_count).as_str(),
 704                style.text.font_size,
 705                &[(
 706                    digit_count,
 707                    RunStyle {
 708                        font_id: style.text.font_id,
 709                        color: Color::black(),
 710                        underline: Default::default(),
 711                    },
 712                )],
 713            )
 714            .width()
 715    }
 716
 717    fn layout_line_numbers(
 718        &self,
 719        rows: Range<u32>,
 720        active_rows: &BTreeMap<u32, bool>,
 721        snapshot: &EditorSnapshot,
 722        cx: &LayoutContext,
 723    ) -> Vec<Option<text_layout::Line>> {
 724        let style = &self.style;
 725        let include_line_numbers = snapshot.mode == EditorMode::Full;
 726        let mut line_number_layouts = Vec::with_capacity(rows.len());
 727        let mut line_number = String::new();
 728        for (ix, row) in snapshot
 729            .buffer_rows(rows.start)
 730            .take((rows.end - rows.start) as usize)
 731            .enumerate()
 732        {
 733            let display_row = rows.start + ix as u32;
 734            let color = if active_rows.contains_key(&display_row) {
 735                style.line_number_active
 736            } else {
 737                style.line_number
 738            };
 739            if let Some(buffer_row) = row {
 740                if include_line_numbers {
 741                    line_number.clear();
 742                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 743                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 744                        &line_number,
 745                        style.text.font_size,
 746                        &[(
 747                            line_number.len(),
 748                            RunStyle {
 749                                font_id: style.text.font_id,
 750                                color,
 751                                underline: Default::default(),
 752                            },
 753                        )],
 754                    )));
 755                }
 756            } else {
 757                line_number_layouts.push(None);
 758            }
 759        }
 760
 761        line_number_layouts
 762    }
 763
 764    fn layout_lines(
 765        &mut self,
 766        rows: Range<u32>,
 767        snapshot: &EditorSnapshot,
 768        cx: &LayoutContext,
 769    ) -> Vec<text_layout::Line> {
 770        if rows.start >= rows.end {
 771            return Vec::new();
 772        }
 773
 774        // When the editor is empty and unfocused, then show the placeholder.
 775        if snapshot.is_empty() && !snapshot.is_focused() {
 776            let placeholder_style = self
 777                .style
 778                .placeholder_text
 779                .as_ref()
 780                .unwrap_or_else(|| &self.style.text);
 781            let placeholder_text = snapshot.placeholder_text();
 782            let placeholder_lines = placeholder_text
 783                .as_ref()
 784                .map_or("", AsRef::as_ref)
 785                .split('\n')
 786                .skip(rows.start as usize)
 787                .chain(iter::repeat(""))
 788                .take(rows.len());
 789            return placeholder_lines
 790                .map(|line| {
 791                    cx.text_layout_cache.layout_str(
 792                        line,
 793                        placeholder_style.font_size,
 794                        &[(
 795                            line.len(),
 796                            RunStyle {
 797                                font_id: placeholder_style.font_id,
 798                                color: placeholder_style.color,
 799                                underline: Default::default(),
 800                            },
 801                        )],
 802                    )
 803                })
 804                .collect();
 805        } else {
 806            let style = &self.style;
 807            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 808                let mut highlight_style = chunk
 809                    .syntax_highlight_id
 810                    .and_then(|id| id.style(&style.syntax));
 811
 812                if let Some(chunk_highlight) = chunk.highlight_style {
 813                    if let Some(highlight_style) = highlight_style.as_mut() {
 814                        highlight_style.highlight(chunk_highlight);
 815                    } else {
 816                        highlight_style = Some(chunk_highlight);
 817                    }
 818                }
 819
 820                let mut diagnostic_highlight = HighlightStyle::default();
 821
 822                if chunk.is_unnecessary {
 823                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
 824                }
 825
 826                if let Some(severity) = chunk.diagnostic_severity {
 827                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
 828                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
 829                        let diagnostic_style = super::diagnostic_style(severity, true, style);
 830                        diagnostic_highlight.underline = Some(Underline {
 831                            color: Some(diagnostic_style.message.text.color),
 832                            thickness: 1.0.into(),
 833                            squiggly: true,
 834                        });
 835                    }
 836                }
 837
 838                if let Some(highlight_style) = highlight_style.as_mut() {
 839                    highlight_style.highlight(diagnostic_highlight);
 840                } else {
 841                    highlight_style = Some(diagnostic_highlight);
 842                }
 843
 844                (chunk.text, highlight_style)
 845            });
 846            layout_highlighted_chunks(
 847                chunks,
 848                &style.text,
 849                &cx.text_layout_cache,
 850                &cx.font_cache,
 851                MAX_LINE_LEN,
 852                rows.len() as usize,
 853            )
 854        }
 855    }
 856
 857    fn layout_blocks(
 858        &mut self,
 859        rows: Range<u32>,
 860        snapshot: &EditorSnapshot,
 861        editor_width: f32,
 862        scroll_width: f32,
 863        gutter_padding: f32,
 864        gutter_width: f32,
 865        em_width: f32,
 866        text_x: f32,
 867        line_height: f32,
 868        style: &EditorStyle,
 869        line_layouts: &[text_layout::Line],
 870        cx: &mut LayoutContext,
 871    ) -> (f32, Vec<BlockLayout>) {
 872        let editor = if let Some(editor) = self.view.upgrade(cx) {
 873            editor
 874        } else {
 875            return Default::default();
 876        };
 877
 878        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
 879        let scroll_x = snapshot.scroll_position.x();
 880        let (fixed_blocks, non_fixed_blocks) = snapshot
 881            .blocks_in_range(rows.clone())
 882            .partition::<Vec<_>, _>(|(_, block)| match block {
 883                TransformBlock::ExcerptHeader { .. } => false,
 884                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
 885            });
 886        let mut render_block = |block: &TransformBlock, width: f32| {
 887            let mut element = match block {
 888                TransformBlock::Custom(block) => {
 889                    let align_to = block
 890                        .position()
 891                        .to_point(&snapshot.buffer_snapshot)
 892                        .to_display_point(snapshot);
 893                    let anchor_x = text_x
 894                        + if rows.contains(&align_to.row()) {
 895                            line_layouts[(align_to.row() - rows.start) as usize]
 896                                .x_for_index(align_to.column() as usize)
 897                        } else {
 898                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 899                                .x_for_index(align_to.column() as usize)
 900                        };
 901
 902                    cx.render(&editor, |_, cx| {
 903                        block.render(&mut BlockContext {
 904                            cx,
 905                            anchor_x,
 906                            gutter_padding,
 907                            line_height,
 908                            scroll_x,
 909                            gutter_width,
 910                            em_width,
 911                        })
 912                    })
 913                }
 914                TransformBlock::ExcerptHeader {
 915                    key,
 916                    buffer,
 917                    range,
 918                    starts_new_buffer,
 919                    ..
 920                } => {
 921                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
 922                        let jump_position = range
 923                            .primary
 924                            .as_ref()
 925                            .map_or(range.context.start, |primary| primary.start);
 926                        let jump_action = crate::Jump {
 927                            path: ProjectPath {
 928                                worktree_id: file.worktree_id(cx),
 929                                path: file.path.clone(),
 930                            },
 931                            position: language::ToPoint::to_point(&jump_position, buffer),
 932                            anchor: jump_position,
 933                        };
 934
 935                        enum JumpIcon {}
 936                        cx.render(&editor, |_, cx| {
 937                            MouseEventHandler::new::<JumpIcon, _, _>(*key, cx, |state, _| {
 938                                let style = style.jump_icon.style_for(state, false);
 939                                Svg::new("icons/jump.svg")
 940                                    .with_color(style.color)
 941                                    .constrained()
 942                                    .with_width(style.icon_width)
 943                                    .aligned()
 944                                    .contained()
 945                                    .with_style(style.container)
 946                                    .constrained()
 947                                    .with_width(style.button_width)
 948                                    .with_height(style.button_width)
 949                                    .boxed()
 950                            })
 951                            .with_cursor_style(CursorStyle::PointingHand)
 952                            .on_click(move |_, _, cx| cx.dispatch_action(jump_action.clone()))
 953                            .with_tooltip::<JumpIcon, _>(
 954                                *key,
 955                                "Jump to Buffer".to_string(),
 956                                Some(Box::new(crate::OpenExcerpts)),
 957                                tooltip_style.clone(),
 958                                cx,
 959                            )
 960                            .aligned()
 961                            .flex_float()
 962                            .boxed()
 963                        })
 964                    });
 965
 966                    if *starts_new_buffer {
 967                        let style = &self.style.diagnostic_path_header;
 968                        let font_size =
 969                            (style.text_scale_factor * self.style.text.font_size).round();
 970
 971                        let mut filename = None;
 972                        let mut parent_path = None;
 973                        if let Some(file) = buffer.file() {
 974                            let path = file.path();
 975                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
 976                            parent_path =
 977                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 978                        }
 979
 980                        Flex::row()
 981                            .with_child(
 982                                Label::new(
 983                                    filename.unwrap_or_else(|| "untitled".to_string()),
 984                                    style.filename.text.clone().with_font_size(font_size),
 985                                )
 986                                .contained()
 987                                .with_style(style.filename.container)
 988                                .aligned()
 989                                .boxed(),
 990                            )
 991                            .with_children(parent_path.map(|path| {
 992                                Label::new(path, style.path.text.clone().with_font_size(font_size))
 993                                    .contained()
 994                                    .with_style(style.path.container)
 995                                    .aligned()
 996                                    .boxed()
 997                            }))
 998                            .with_children(jump_icon)
 999                            .contained()
1000                            .with_style(style.container)
1001                            .with_padding_left(gutter_padding)
1002                            .with_padding_right(gutter_padding)
1003                            .expanded()
1004                            .named("path header block")
1005                    } else {
1006                        let text_style = self.style.text.clone();
1007                        Flex::row()
1008                            .with_child(Label::new("".to_string(), text_style).boxed())
1009                            .with_children(jump_icon)
1010                            .contained()
1011                            .with_padding_left(gutter_padding)
1012                            .with_padding_right(gutter_padding)
1013                            .expanded()
1014                            .named("collapsed context")
1015                    }
1016                }
1017            };
1018
1019            element.layout(
1020                SizeConstraint {
1021                    min: Vector2F::zero(),
1022                    max: vec2f(width, block.height() as f32 * line_height),
1023                },
1024                cx,
1025            );
1026            element
1027        };
1028
1029        let mut fixed_block_max_width = 0f32;
1030        let mut blocks = Vec::new();
1031        for (row, block) in fixed_blocks {
1032            let element = render_block(block, f32::INFINITY);
1033            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1034            blocks.push(BlockLayout {
1035                row,
1036                element,
1037                style: BlockStyle::Fixed,
1038            });
1039        }
1040        for (row, block) in non_fixed_blocks {
1041            let style = match block {
1042                TransformBlock::Custom(block) => block.style(),
1043                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1044            };
1045            let width = match style {
1046                BlockStyle::Sticky => editor_width,
1047                BlockStyle::Flex => editor_width
1048                    .max(fixed_block_max_width)
1049                    .max(gutter_width + scroll_width),
1050                BlockStyle::Fixed => unreachable!(),
1051            };
1052            let element = render_block(block, width);
1053            blocks.push(BlockLayout {
1054                row,
1055                element,
1056                style,
1057            });
1058        }
1059        (
1060            scroll_width.max(fixed_block_max_width - gutter_width),
1061            blocks,
1062        )
1063    }
1064}
1065
1066impl Element for EditorElement {
1067    type LayoutState = LayoutState;
1068    type PaintState = PaintState;
1069
1070    fn layout(
1071        &mut self,
1072        constraint: SizeConstraint,
1073        cx: &mut LayoutContext,
1074    ) -> (Vector2F, Self::LayoutState) {
1075        let mut size = constraint.max;
1076        if size.x().is_infinite() {
1077            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1078        }
1079
1080        let snapshot = self.snapshot(cx.app);
1081        let style = self.style.clone();
1082        let line_height = style.text.line_height(cx.font_cache);
1083
1084        let gutter_padding;
1085        let gutter_width;
1086        let gutter_margin;
1087        if snapshot.mode == EditorMode::Full {
1088            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
1089            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1090            gutter_margin = -style.text.descent(cx.font_cache);
1091        } else {
1092            gutter_padding = 0.0;
1093            gutter_width = 0.0;
1094            gutter_margin = 0.0;
1095        };
1096
1097        let text_width = size.x() - gutter_width;
1098        let em_width = style.text.em_width(cx.font_cache);
1099        let em_advance = style.text.em_advance(cx.font_cache);
1100        let overscroll = vec2f(em_width, 0.);
1101        let snapshot = self.update_view(cx.app, |view, cx| {
1102            let wrap_width = match view.soft_wrap_mode(cx) {
1103                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
1104                SoftWrap::EditorWidth => {
1105                    Some(text_width - gutter_margin - overscroll.x() - em_width)
1106                }
1107                SoftWrap::Column(column) => Some(column as f32 * em_advance),
1108            };
1109
1110            if view.set_wrap_width(wrap_width, cx) {
1111                view.snapshot(cx)
1112            } else {
1113                snapshot
1114            }
1115        });
1116
1117        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1118        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1119            size.set_y(
1120                scroll_height
1121                    .min(constraint.max_along(Axis::Vertical))
1122                    .max(constraint.min_along(Axis::Vertical))
1123                    .min(line_height * max_lines as f32),
1124            )
1125        } else if let EditorMode::SingleLine = snapshot.mode {
1126            size.set_y(
1127                line_height
1128                    .min(constraint.max_along(Axis::Vertical))
1129                    .max(constraint.min_along(Axis::Vertical)),
1130            )
1131        } else if size.y().is_infinite() {
1132            size.set_y(scroll_height);
1133        }
1134        let gutter_size = vec2f(gutter_width, size.y());
1135        let text_size = vec2f(text_width, size.y());
1136
1137        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
1138            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
1139            let snapshot = view.snapshot(cx);
1140            (autoscroll_horizontally, snapshot)
1141        });
1142
1143        let scroll_position = snapshot.scroll_position();
1144        let start_row = scroll_position.y() as u32;
1145        let scroll_top = scroll_position.y() * line_height;
1146
1147        // Add 1 to ensure selections bleed off screen
1148        let end_row = 1 + cmp::min(
1149            ((scroll_top + size.y()) / line_height).ceil() as u32,
1150            snapshot.max_point().row(),
1151        );
1152
1153        let start_anchor = if start_row == 0 {
1154            Anchor::min()
1155        } else {
1156            snapshot
1157                .buffer_snapshot
1158                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1159        };
1160        let end_anchor = if end_row > snapshot.max_point().row() {
1161            Anchor::max()
1162        } else {
1163            snapshot
1164                .buffer_snapshot
1165                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1166        };
1167
1168        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1169        let mut active_rows = BTreeMap::new();
1170        let mut highlighted_rows = None;
1171        let mut highlighted_ranges = Vec::new();
1172        self.update_view(cx.app, |view, cx| {
1173            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1174
1175            highlighted_rows = view.highlighted_rows();
1176            let theme = cx.global::<Settings>().theme.as_ref();
1177            highlighted_ranges = view.background_highlights_in_range(
1178                start_anchor.clone()..end_anchor.clone(),
1179                &display_map,
1180                theme,
1181            );
1182
1183            let mut remote_selections = HashMap::default();
1184            for (replica_id, line_mode, selection) in display_map
1185                .buffer_snapshot
1186                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1187            {
1188                // The local selections match the leader's selections.
1189                if Some(replica_id) == view.leader_replica_id {
1190                    continue;
1191                }
1192                remote_selections
1193                    .entry(replica_id)
1194                    .or_insert(Vec::new())
1195                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1196            }
1197            selections.extend(remote_selections);
1198
1199            if view.show_local_selections {
1200                let mut local_selections = view
1201                    .selections
1202                    .disjoint_in_range(start_anchor..end_anchor, cx);
1203                local_selections.extend(view.selections.pending(cx));
1204                for selection in &local_selections {
1205                    let is_empty = selection.start == selection.end;
1206                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1207                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1208                    for row in cmp::max(selection_start.row(), start_row)
1209                        ..=cmp::min(selection_end.row(), end_row)
1210                    {
1211                        let contains_non_empty_selection =
1212                            active_rows.entry(row).or_insert(!is_empty);
1213                        *contains_non_empty_selection |= !is_empty;
1214                    }
1215                }
1216
1217                // Render the local selections in the leader's color when following.
1218                let local_replica_id = view.leader_replica_id.unwrap_or(view.replica_id(cx));
1219
1220                selections.push((
1221                    local_replica_id,
1222                    local_selections
1223                        .into_iter()
1224                        .map(|selection| {
1225                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1226                        })
1227                        .collect(),
1228                ));
1229            }
1230        });
1231
1232        let line_number_layouts =
1233            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1234
1235        let mut max_visible_line_width = 0.0;
1236        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1237        for line in &line_layouts {
1238            if line.width() > max_visible_line_width {
1239                max_visible_line_width = line.width();
1240            }
1241        }
1242
1243        let style = self.style.clone();
1244        let longest_line_width = layout_line(
1245            snapshot.longest_row(),
1246            &snapshot,
1247            &style,
1248            cx.text_layout_cache,
1249        )
1250        .width();
1251        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1252        let em_width = style.text.em_width(cx.font_cache);
1253        let (scroll_width, blocks) = self.layout_blocks(
1254            start_row..end_row,
1255            &snapshot,
1256            size.x(),
1257            scroll_width,
1258            gutter_padding,
1259            gutter_width,
1260            em_width,
1261            gutter_width + gutter_margin,
1262            line_height,
1263            &style,
1264            &line_layouts,
1265            cx,
1266        );
1267
1268        let max_row = snapshot.max_point().row();
1269        let scroll_max = vec2f(
1270            ((scroll_width - text_size.x()) / em_width).max(0.0),
1271            max_row.saturating_sub(1) as f32,
1272        );
1273
1274        self.update_view(cx.app, |view, cx| {
1275            let clamped = view.clamp_scroll_left(scroll_max.x());
1276            let autoscrolled;
1277            if autoscroll_horizontally {
1278                autoscrolled = view.autoscroll_horizontally(
1279                    start_row,
1280                    text_size.x(),
1281                    scroll_width,
1282                    em_width,
1283                    &line_layouts,
1284                    cx,
1285                );
1286            } else {
1287                autoscrolled = false;
1288            }
1289
1290            if clamped || autoscrolled {
1291                snapshot = view.snapshot(cx);
1292            }
1293        });
1294
1295        let mut context_menu = None;
1296        let mut code_actions_indicator = None;
1297        let mut hover = None;
1298        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1299            let newest_selection_head = view
1300                .selections
1301                .newest::<usize>(cx)
1302                .head()
1303                .to_display_point(&snapshot);
1304
1305            let style = view.style(cx);
1306            if (start_row..end_row).contains(&newest_selection_head.row()) {
1307                if view.context_menu_visible() {
1308                    context_menu =
1309                        view.render_context_menu(newest_selection_head, style.clone(), cx);
1310                }
1311
1312                code_actions_indicator = view
1313                    .render_code_actions_indicator(&style, cx)
1314                    .map(|indicator| (newest_selection_head.row(), indicator));
1315            }
1316
1317            hover = view.hover_state.popover.clone().and_then(|hover| {
1318                let (point, rendered) = hover.render(&snapshot, style.clone(), cx);
1319                if point.row() >= snapshot.scroll_position().y() as u32 {
1320                    if line_layouts.len() > (point.row() - start_row) as usize {
1321                        return Some((point, rendered));
1322                    }
1323                }
1324
1325                None
1326            });
1327        });
1328
1329        if let Some((_, context_menu)) = context_menu.as_mut() {
1330            context_menu.layout(
1331                SizeConstraint {
1332                    min: Vector2F::zero(),
1333                    max: vec2f(
1334                        cx.window_size.x() * 0.7,
1335                        (12. * line_height).min((size.y() - line_height) / 2.),
1336                    ),
1337                },
1338                cx,
1339            );
1340        }
1341
1342        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1343            indicator.layout(
1344                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
1345                cx,
1346            );
1347        }
1348
1349        if let Some((_, hover)) = hover.as_mut() {
1350            hover.layout(
1351                SizeConstraint {
1352                    min: Vector2F::zero(),
1353                    max: vec2f(
1354                        (120. * em_width) // Default size
1355                            .min(size.x() / 2.) // Shrink to half of the editor width
1356                            .max(20. * em_width), // Apply minimum width of 20 characters
1357                        (16. * line_height) // Default size
1358                            .min(size.y() / 2.) // Shrink to half of the editor height
1359                            .max(4. * line_height), // Apply minimum height of 4 lines
1360                    ),
1361                },
1362                cx,
1363            );
1364        }
1365
1366        (
1367            size,
1368            LayoutState {
1369                size,
1370                scroll_max,
1371                gutter_size,
1372                gutter_padding,
1373                text_size,
1374                gutter_margin,
1375                snapshot,
1376                active_rows,
1377                highlighted_rows,
1378                highlighted_ranges,
1379                line_layouts,
1380                line_number_layouts,
1381                blocks,
1382                line_height,
1383                em_width,
1384                em_advance,
1385                selections,
1386                context_menu,
1387                code_actions_indicator,
1388                hover,
1389            },
1390        )
1391    }
1392
1393    fn paint(
1394        &mut self,
1395        bounds: RectF,
1396        visible_bounds: RectF,
1397        layout: &mut Self::LayoutState,
1398        cx: &mut PaintContext,
1399    ) -> Self::PaintState {
1400        cx.scene.push_layer(Some(bounds));
1401
1402        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1403        let text_bounds = RectF::new(
1404            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1405            layout.text_size,
1406        );
1407
1408        let mut paint_state = PaintState {
1409            bounds,
1410            gutter_bounds,
1411            text_bounds,
1412            context_menu_bounds: None,
1413            hover_bounds: None,
1414        };
1415
1416        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1417        if layout.gutter_size.x() > 0. {
1418            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1419        }
1420        self.paint_text(text_bounds, visible_bounds, layout, &mut paint_state, cx);
1421
1422        if !layout.blocks.is_empty() {
1423            cx.scene.push_layer(Some(bounds));
1424            self.paint_blocks(bounds, visible_bounds, layout, cx);
1425            cx.scene.pop_layer();
1426        }
1427
1428        cx.scene.pop_layer();
1429
1430        paint_state
1431    }
1432
1433    fn dispatch_event(
1434        &mut self,
1435        event: &Event,
1436        _: RectF,
1437        _: RectF,
1438        layout: &mut LayoutState,
1439        paint: &mut PaintState,
1440        cx: &mut EventContext,
1441    ) -> bool {
1442        if let Some((_, context_menu)) = &mut layout.context_menu {
1443            if context_menu.dispatch_event(event, cx) {
1444                return true;
1445            }
1446        }
1447
1448        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1449            if indicator.dispatch_event(event, cx) {
1450                return true;
1451            }
1452        }
1453
1454        if let Some((_, hover)) = &mut layout.hover {
1455            if hover.dispatch_event(event, cx) {
1456                return true;
1457            }
1458        }
1459
1460        for block in &mut layout.blocks {
1461            if block.element.dispatch_event(event, cx) {
1462                return true;
1463            }
1464        }
1465
1466        match event {
1467            Event::MouseDown(MouseEvent {
1468                button: MouseButton::Left,
1469                position,
1470                cmd,
1471                alt,
1472                shift,
1473                click_count,
1474                ..
1475            }) => self.mouse_down(
1476                *position,
1477                *cmd,
1478                *alt,
1479                *shift,
1480                *click_count,
1481                layout,
1482                paint,
1483                cx,
1484            ),
1485            Event::MouseUp(MouseEvent {
1486                button: MouseButton::Left,
1487                position,
1488                ..
1489            }) => self.mouse_up(*position, cx),
1490            Event::MouseMoved(MouseMovedEvent {
1491                pressed_button: Some(MouseButton::Left),
1492                position,
1493                ..
1494            }) => self.mouse_dragged(*position, layout, paint, cx),
1495            Event::ScrollWheel(ScrollWheelEvent {
1496                position,
1497                delta,
1498                precise,
1499            }) => self.scroll(*position, *delta, *precise, layout, paint, cx),
1500            Event::KeyDown(KeyDownEvent { input, .. }) => self.key_down(input.as_deref(), cx),
1501            Event::ModifiersChanged(ModifiersChangedEvent { cmd, .. }) => {
1502                self.modifiers_changed(*cmd, cx)
1503            }
1504            Event::MouseMoved(MouseMovedEvent { position, cmd, .. }) => {
1505                self.mouse_moved(*position, *cmd, layout, paint, cx)
1506            }
1507
1508            _ => false,
1509        }
1510    }
1511
1512    fn debug(
1513        &self,
1514        bounds: RectF,
1515        _: &Self::LayoutState,
1516        _: &Self::PaintState,
1517        _: &gpui::DebugContext,
1518    ) -> json::Value {
1519        json!({
1520            "type": "BufferElement",
1521            "bounds": bounds.to_json()
1522        })
1523    }
1524}
1525
1526pub struct LayoutState {
1527    size: Vector2F,
1528    scroll_max: Vector2F,
1529    gutter_size: Vector2F,
1530    gutter_padding: f32,
1531    gutter_margin: f32,
1532    text_size: Vector2F,
1533    snapshot: EditorSnapshot,
1534    active_rows: BTreeMap<u32, bool>,
1535    highlighted_rows: Option<Range<u32>>,
1536    line_layouts: Vec<text_layout::Line>,
1537    line_number_layouts: Vec<Option<text_layout::Line>>,
1538    blocks: Vec<BlockLayout>,
1539    line_height: f32,
1540    em_width: f32,
1541    em_advance: f32,
1542    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1543    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1544    context_menu: Option<(DisplayPoint, ElementBox)>,
1545    code_actions_indicator: Option<(u32, ElementBox)>,
1546    hover: Option<(DisplayPoint, ElementBox)>,
1547}
1548
1549struct BlockLayout {
1550    row: u32,
1551    element: ElementBox,
1552    style: BlockStyle,
1553}
1554
1555fn layout_line(
1556    row: u32,
1557    snapshot: &EditorSnapshot,
1558    style: &EditorStyle,
1559    layout_cache: &TextLayoutCache,
1560) -> text_layout::Line {
1561    let mut line = snapshot.line(row);
1562
1563    if line.len() > MAX_LINE_LEN {
1564        let mut len = MAX_LINE_LEN;
1565        while !line.is_char_boundary(len) {
1566            len -= 1;
1567        }
1568
1569        line.truncate(len);
1570    }
1571
1572    layout_cache.layout_str(
1573        &line,
1574        style.text.font_size,
1575        &[(
1576            snapshot.line_len(row) as usize,
1577            RunStyle {
1578                font_id: style.text.font_id,
1579                color: Color::black(),
1580                underline: Default::default(),
1581            },
1582        )],
1583    )
1584}
1585
1586pub struct PaintState {
1587    bounds: RectF,
1588    gutter_bounds: RectF,
1589    text_bounds: RectF,
1590    context_menu_bounds: Option<RectF>,
1591    hover_bounds: Option<RectF>,
1592}
1593
1594impl PaintState {
1595    /// Returns two display points. The first is the nearest valid
1596    /// position in the current buffer and the second is the distance to the
1597    /// nearest valid position if there was overshoot.
1598    fn point_for_position(
1599        &self,
1600        snapshot: &EditorSnapshot,
1601        layout: &LayoutState,
1602        position: Vector2F,
1603    ) -> (DisplayPoint, DisplayPoint) {
1604        let scroll_position = snapshot.scroll_position();
1605        let position = position - self.text_bounds.origin();
1606        let y = position.y().max(0.0).min(layout.size.y());
1607        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1608        let row_overshoot = row.saturating_sub(snapshot.max_point().row());
1609        let row = cmp::min(row, snapshot.max_point().row());
1610        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1611        let x = position.x() + (scroll_position.x() * layout.em_width);
1612
1613        let column = if x >= 0.0 {
1614            line.index_for_x(x)
1615                .map(|ix| ix as u32)
1616                .unwrap_or_else(|| snapshot.line_len(row))
1617        } else {
1618            0
1619        };
1620        let column_overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1621
1622        (
1623            DisplayPoint::new(row, column),
1624            DisplayPoint::new(row_overshoot, column_overshoot),
1625        )
1626    }
1627}
1628
1629#[derive(Copy, Clone, PartialEq, Eq, Debug)]
1630pub enum CursorShape {
1631    Bar,
1632    Block,
1633    Underscore,
1634}
1635
1636impl Default for CursorShape {
1637    fn default() -> Self {
1638        CursorShape::Bar
1639    }
1640}
1641
1642#[derive(Debug)]
1643pub struct Cursor {
1644    origin: Vector2F,
1645    block_width: f32,
1646    line_height: f32,
1647    color: Color,
1648    shape: CursorShape,
1649    block_text: Option<Line>,
1650}
1651
1652impl Cursor {
1653    pub fn new(
1654        origin: Vector2F,
1655        block_width: f32,
1656        line_height: f32,
1657        color: Color,
1658        shape: CursorShape,
1659        block_text: Option<Line>,
1660    ) -> Cursor {
1661        Cursor {
1662            origin,
1663            block_width,
1664            line_height,
1665            color,
1666            shape,
1667            block_text,
1668        }
1669    }
1670
1671    pub fn paint(&self, origin: Vector2F, cx: &mut PaintContext) {
1672        let bounds = match self.shape {
1673            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
1674            CursorShape::Block => RectF::new(
1675                self.origin + origin,
1676                vec2f(self.block_width, self.line_height),
1677            ),
1678            CursorShape::Underscore => RectF::new(
1679                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
1680                vec2f(self.block_width, 2.0),
1681            ),
1682        };
1683
1684        cx.scene.push_quad(Quad {
1685            bounds,
1686            background: Some(self.color),
1687            border: Border::new(0., Color::black()),
1688            corner_radius: 0.,
1689        });
1690
1691        if let Some(block_text) = &self.block_text {
1692            block_text.paint(self.origin + origin, bounds, self.line_height, cx);
1693        }
1694    }
1695}
1696
1697#[derive(Debug)]
1698struct HighlightedRange {
1699    start_y: f32,
1700    line_height: f32,
1701    lines: Vec<HighlightedRangeLine>,
1702    color: Color,
1703    corner_radius: f32,
1704}
1705
1706#[derive(Debug)]
1707struct HighlightedRangeLine {
1708    start_x: f32,
1709    end_x: f32,
1710}
1711
1712impl HighlightedRange {
1713    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1714        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1715            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1716            self.paint_lines(
1717                self.start_y + self.line_height,
1718                &self.lines[1..],
1719                bounds,
1720                scene,
1721            );
1722        } else {
1723            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1724        }
1725    }
1726
1727    fn paint_lines(
1728        &self,
1729        start_y: f32,
1730        lines: &[HighlightedRangeLine],
1731        bounds: RectF,
1732        scene: &mut Scene,
1733    ) {
1734        if lines.is_empty() {
1735            return;
1736        }
1737
1738        let mut path = PathBuilder::new();
1739        let first_line = lines.first().unwrap();
1740        let last_line = lines.last().unwrap();
1741
1742        let first_top_left = vec2f(first_line.start_x, start_y);
1743        let first_top_right = vec2f(first_line.end_x, start_y);
1744
1745        let curve_height = vec2f(0., self.corner_radius);
1746        let curve_width = |start_x: f32, end_x: f32| {
1747            let max = (end_x - start_x) / 2.;
1748            let width = if max < self.corner_radius {
1749                max
1750            } else {
1751                self.corner_radius
1752            };
1753
1754            vec2f(width, 0.)
1755        };
1756
1757        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1758        path.reset(first_top_right - top_curve_width);
1759        path.curve_to(first_top_right + curve_height, first_top_right);
1760
1761        let mut iter = lines.iter().enumerate().peekable();
1762        while let Some((ix, line)) = iter.next() {
1763            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1764
1765            if let Some((_, next_line)) = iter.peek() {
1766                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1767
1768                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1769                    Ordering::Equal => {
1770                        path.line_to(bottom_right);
1771                    }
1772                    Ordering::Less => {
1773                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1774                        path.line_to(bottom_right - curve_height);
1775                        if self.corner_radius > 0. {
1776                            path.curve_to(bottom_right - curve_width, bottom_right);
1777                        }
1778                        path.line_to(next_top_right + curve_width);
1779                        if self.corner_radius > 0. {
1780                            path.curve_to(next_top_right + curve_height, next_top_right);
1781                        }
1782                    }
1783                    Ordering::Greater => {
1784                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1785                        path.line_to(bottom_right - curve_height);
1786                        if self.corner_radius > 0. {
1787                            path.curve_to(bottom_right + curve_width, bottom_right);
1788                        }
1789                        path.line_to(next_top_right - curve_width);
1790                        if self.corner_radius > 0. {
1791                            path.curve_to(next_top_right + curve_height, next_top_right);
1792                        }
1793                    }
1794                }
1795            } else {
1796                let curve_width = curve_width(line.start_x, line.end_x);
1797                path.line_to(bottom_right - curve_height);
1798                if self.corner_radius > 0. {
1799                    path.curve_to(bottom_right - curve_width, bottom_right);
1800                }
1801
1802                let bottom_left = vec2f(line.start_x, bottom_right.y());
1803                path.line_to(bottom_left + curve_width);
1804                if self.corner_radius > 0. {
1805                    path.curve_to(bottom_left - curve_height, bottom_left);
1806                }
1807            }
1808        }
1809
1810        if first_line.start_x > last_line.start_x {
1811            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1812            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1813            path.line_to(second_top_left + curve_height);
1814            if self.corner_radius > 0. {
1815                path.curve_to(second_top_left + curve_width, second_top_left);
1816            }
1817            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1818            path.line_to(first_bottom_left - curve_width);
1819            if self.corner_radius > 0. {
1820                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1821            }
1822        }
1823
1824        path.line_to(first_top_left + curve_height);
1825        if self.corner_radius > 0. {
1826            path.curve_to(first_top_left + top_curve_width, first_top_left);
1827        }
1828        path.line_to(first_top_right - top_curve_width);
1829
1830        scene.push_path(path.build(self.color, Some(bounds)));
1831    }
1832}
1833
1834fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1835    delta.powf(1.5) / 100.0
1836}
1837
1838fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1839    delta.powf(1.2) / 300.0
1840}
1841
1842#[cfg(test)]
1843mod tests {
1844    use std::sync::Arc;
1845
1846    use super::*;
1847    use crate::{
1848        display_map::{BlockDisposition, BlockProperties},
1849        Editor, MultiBuffer,
1850    };
1851    use settings::Settings;
1852    use util::test::sample_text;
1853
1854    #[gpui::test]
1855    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1856        cx.set_global(Settings::test(cx));
1857        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1858        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1859            Editor::new(EditorMode::Full, buffer, None, None, cx)
1860        });
1861        let element = EditorElement::new(
1862            editor.downgrade(),
1863            editor.read(cx).style(cx),
1864            CursorShape::Bar,
1865        );
1866
1867        let layouts = editor.update(cx, |editor, cx| {
1868            let snapshot = editor.snapshot(cx);
1869            let mut presenter = cx.build_presenter(window_id, 30.);
1870            let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1871            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1872        });
1873        assert_eq!(layouts.len(), 6);
1874    }
1875
1876    #[gpui::test]
1877    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
1878        cx.set_global(Settings::test(cx));
1879        let buffer = MultiBuffer::build_simple("", cx);
1880        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1881            Editor::new(EditorMode::Full, buffer, None, None, cx)
1882        });
1883
1884        editor.update(cx, |editor, cx| {
1885            editor.set_placeholder_text("hello", cx);
1886            editor.insert_blocks(
1887                [BlockProperties {
1888                    style: BlockStyle::Fixed,
1889                    disposition: BlockDisposition::Above,
1890                    height: 3,
1891                    position: Anchor::min(),
1892                    render: Arc::new(|_| Empty::new().boxed()),
1893                }],
1894                cx,
1895            );
1896
1897            // Blur the editor so that it displays placeholder text.
1898            cx.blur();
1899        });
1900
1901        let mut element = EditorElement::new(
1902            editor.downgrade(),
1903            editor.read(cx).style(cx),
1904            CursorShape::Bar,
1905        );
1906
1907        let mut scene = Scene::new(1.0);
1908        let mut presenter = cx.build_presenter(window_id, 30.);
1909        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1910        let (size, mut state) = element.layout(
1911            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
1912            &mut layout_cx,
1913        );
1914
1915        assert_eq!(state.line_layouts.len(), 4);
1916        assert_eq!(
1917            state
1918                .line_number_layouts
1919                .iter()
1920                .map(Option::is_some)
1921                .collect::<Vec<_>>(),
1922            &[false, false, false, true]
1923        );
1924
1925        // Don't panic.
1926        let bounds = RectF::new(Default::default(), size);
1927        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
1928        element.paint(bounds, bounds, &mut state, &mut paint_cx);
1929    }
1930}