element.rs

   1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSnapshot, 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::{
  10        CmdShiftChanged, GoToFetchedDefinition, GoToFetchedTypeDefinition, UpdateGoToDefinitionLink,
  11    },
  12    mouse_context_menu::DeployMouseContextMenu,
  13    EditorStyle,
  14};
  15use clock::ReplicaId;
  16use collections::{BTreeMap, HashMap};
  17use gpui::{
  18    color::Color,
  19    elements::*,
  20    fonts::{HighlightStyle, Underline},
  21    geometry::{
  22        rect::RectF,
  23        vector::{vec2f, Vector2F},
  24        PathBuilder,
  25    },
  26    json::{self, ToJson},
  27    platform::CursorStyle,
  28    text_layout::{self, Line, RunStyle, TextLayoutCache},
  29    AppContext, Axis, Border, CursorRegion, Element, ElementBox, Event, EventContext,
  30    LayoutContext, ModifiersChangedEvent, MouseButton, MouseButtonEvent, MouseMovedEvent,
  31    MutableAppContext, PaintContext, Quad, Scene, ScrollWheelEvent, SizeConstraint, ViewContext,
  32    WeakViewHandle,
  33};
  34use json::json;
  35use language::{Bias, DiagnosticSeverity, OffsetUtf16, Selection};
  36use project::ProjectPath;
  37use settings::Settings;
  38use smallvec::SmallVec;
  39use std::{
  40    cmp::{self, Ordering},
  41    fmt::Write,
  42    iter,
  43    ops::Range,
  44};
  45
  46const MIN_POPOVER_CHARACTER_WIDTH: f32 = 20.;
  47const MIN_POPOVER_LINE_HEIGHT: f32 = 4.;
  48const HOVER_POPOVER_GAP: f32 = 10.;
  49
  50struct SelectionLayout {
  51    head: DisplayPoint,
  52    range: Range<DisplayPoint>,
  53}
  54
  55impl SelectionLayout {
  56    fn new<T: ToPoint + ToDisplayPoint + Clone>(
  57        selection: Selection<T>,
  58        line_mode: bool,
  59        map: &DisplaySnapshot,
  60    ) -> Self {
  61        if line_mode {
  62            let selection = selection.map(|p| p.to_point(&map.buffer_snapshot));
  63            let point_range = map.expand_to_line(selection.range());
  64            Self {
  65                head: selection.head().to_display_point(map),
  66                range: point_range.start.to_display_point(map)
  67                    ..point_range.end.to_display_point(map),
  68            }
  69        } else {
  70            let selection = selection.map(|p| p.to_display_point(map));
  71            Self {
  72                head: selection.head(),
  73                range: selection.range(),
  74            }
  75        }
  76    }
  77}
  78
  79pub struct EditorElement {
  80    view: WeakViewHandle<Editor>,
  81    style: EditorStyle,
  82    cursor_shape: CursorShape,
  83}
  84
  85impl EditorElement {
  86    pub fn new(
  87        view: WeakViewHandle<Editor>,
  88        style: EditorStyle,
  89        cursor_shape: CursorShape,
  90    ) -> Self {
  91        Self {
  92            view,
  93            style,
  94            cursor_shape,
  95        }
  96    }
  97
  98    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  99        self.view.upgrade(cx).unwrap().read(cx)
 100    }
 101
 102    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
 103    where
 104        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
 105    {
 106        self.view.upgrade(cx).unwrap().update(cx, f)
 107    }
 108
 109    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
 110        self.update_view(cx, |view, cx| view.snapshot(cx))
 111    }
 112
 113    fn mouse_down(
 114        &self,
 115        position: Vector2F,
 116        cmd: bool,
 117        alt: bool,
 118        shift: bool,
 119        mut click_count: usize,
 120        layout: &mut LayoutState,
 121        paint: &mut PaintState,
 122        cx: &mut EventContext,
 123    ) -> bool {
 124        if cmd && paint.text_bounds.contains_point(position) {
 125            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 126            if overshoot.is_zero() {
 127                if shift {
 128                    cx.dispatch_action(GoToFetchedTypeDefinition { point });
 129                } else {
 130                    cx.dispatch_action(GoToFetchedDefinition { point });
 131                }
 132
 133                return true;
 134            }
 135        }
 136
 137        if paint.gutter_bounds.contains_point(position) {
 138            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
 139        } else if !paint.text_bounds.contains_point(position) {
 140            return false;
 141        }
 142
 143        let snapshot = self.snapshot(cx.app);
 144        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 145
 146        if shift && alt {
 147            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
 148                position,
 149                overshoot: overshoot.column(),
 150            }));
 151        } else if shift {
 152            cx.dispatch_action(Select(SelectPhase::Extend {
 153                position,
 154                click_count,
 155            }));
 156        } else {
 157            cx.dispatch_action(Select(SelectPhase::Begin {
 158                position,
 159                add: alt,
 160                click_count,
 161            }));
 162        }
 163
 164        true
 165    }
 166
 167    fn mouse_right_down(
 168        &self,
 169        position: Vector2F,
 170        layout: &mut LayoutState,
 171        paint: &mut PaintState,
 172        cx: &mut EventContext,
 173    ) -> bool {
 174        if !paint.text_bounds.contains_point(position) {
 175            return false;
 176        }
 177
 178        let snapshot = self.snapshot(cx.app);
 179        let (point, _) = paint.point_for_position(&snapshot, layout, position);
 180
 181        cx.dispatch_action(DeployMouseContextMenu { position, point });
 182        true
 183    }
 184
 185    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
 186        if self.view(cx.app.as_ref()).is_selecting() {
 187            cx.dispatch_action(Select(SelectPhase::End));
 188            true
 189        } else {
 190            false
 191        }
 192    }
 193
 194    fn mouse_dragged(
 195        &self,
 196        position: Vector2F,
 197        layout: &mut LayoutState,
 198        paint: &mut PaintState,
 199        cx: &mut EventContext,
 200    ) -> bool {
 201        let view = self.view(cx.app.as_ref());
 202
 203        if view.is_selecting() {
 204            let rect = paint.text_bounds;
 205            let mut scroll_delta = Vector2F::zero();
 206
 207            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 208            let top = rect.origin_y() + vertical_margin;
 209            let bottom = rect.lower_left().y() - vertical_margin;
 210            if position.y() < top {
 211                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 212            }
 213            if position.y() > bottom {
 214                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 215            }
 216
 217            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 218            let left = rect.origin_x() + horizontal_margin;
 219            let right = rect.upper_right().x() - horizontal_margin;
 220            if position.x() < left {
 221                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 222                    left - position.x(),
 223                ))
 224            }
 225            if position.x() > right {
 226                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 227                    position.x() - right,
 228                ))
 229            }
 230
 231            let snapshot = self.snapshot(cx.app);
 232            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 233
 234            cx.dispatch_action(Select(SelectPhase::Update {
 235                position,
 236                overshoot: overshoot.column(),
 237                scroll_position: (snapshot.scroll_position() + scroll_delta)
 238                    .clamp(Vector2F::zero(), layout.scroll_max),
 239            }));
 240            true
 241        } else {
 242            false
 243        }
 244    }
 245
 246    fn mouse_moved(
 247        &self,
 248        MouseMovedEvent {
 249            cmd,
 250            shift,
 251            position,
 252            ..
 253        }: MouseMovedEvent,
 254        layout: &LayoutState,
 255        paint: &PaintState,
 256        cx: &mut EventContext,
 257    ) -> bool {
 258        // This will be handled more correctly once https://github.com/zed-industries/zed/issues/1218 is completed
 259        // Don't trigger hover popover if mouse is hovering over context menu
 260        let point = if paint.text_bounds.contains_point(position) {
 261            let (point, overshoot) = paint.point_for_position(&self.snapshot(cx), layout, position);
 262            if overshoot.is_zero() {
 263                Some(point)
 264            } else {
 265                None
 266            }
 267        } else {
 268            None
 269        };
 270
 271        cx.dispatch_action(UpdateGoToDefinitionLink {
 272            point,
 273            cmd_held: cmd,
 274            shift_held: shift,
 275        });
 276
 277        if paint
 278            .context_menu_bounds
 279            .map_or(false, |context_menu_bounds| {
 280                context_menu_bounds.contains_point(position)
 281            })
 282        {
 283            return false;
 284        }
 285
 286        if paint
 287            .hover_popover_bounds
 288            .iter()
 289            .any(|hover_bounds| hover_bounds.contains_point(position))
 290        {
 291            return false;
 292        }
 293
 294        cx.dispatch_action(HoverAt { point });
 295        true
 296    }
 297
 298    fn modifiers_changed(&self, event: ModifiersChangedEvent, cx: &mut EventContext) -> bool {
 299        cx.dispatch_action(CmdShiftChanged {
 300            cmd_down: event.cmd,
 301            shift_down: event.shift,
 302        });
 303        false
 304    }
 305
 306    fn scroll(
 307        &self,
 308        position: Vector2F,
 309        mut delta: Vector2F,
 310        precise: bool,
 311        layout: &mut LayoutState,
 312        paint: &mut PaintState,
 313        cx: &mut EventContext,
 314    ) -> bool {
 315        if !paint.bounds.contains_point(position) {
 316            return false;
 317        }
 318
 319        let snapshot = self.snapshot(cx.app);
 320        let max_glyph_width = layout.em_width;
 321        if !precise {
 322            delta *= vec2f(max_glyph_width, layout.line_height);
 323        }
 324
 325        let scroll_position = snapshot.scroll_position();
 326        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 327        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 328        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 329
 330        cx.dispatch_action(Scroll(scroll_position));
 331
 332        true
 333    }
 334
 335    fn paint_background(
 336        &self,
 337        gutter_bounds: RectF,
 338        text_bounds: RectF,
 339        layout: &LayoutState,
 340        cx: &mut PaintContext,
 341    ) {
 342        let bounds = gutter_bounds.union_rect(text_bounds);
 343        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 344        let editor = self.view(cx.app);
 345        cx.scene.push_quad(Quad {
 346            bounds: gutter_bounds,
 347            background: Some(self.style.gutter_background),
 348            border: Border::new(0., Color::transparent_black()),
 349            corner_radius: 0.,
 350        });
 351        cx.scene.push_quad(Quad {
 352            bounds: text_bounds,
 353            background: Some(self.style.background),
 354            border: Border::new(0., Color::transparent_black()),
 355            corner_radius: 0.,
 356        });
 357
 358        if let EditorMode::Full = editor.mode {
 359            let mut active_rows = layout.active_rows.iter().peekable();
 360            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 361                let mut end_row = *start_row;
 362                while active_rows.peek().map_or(false, |r| {
 363                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 364                }) {
 365                    active_rows.next().unwrap();
 366                    end_row += 1;
 367                }
 368
 369                if !contains_non_empty_selection {
 370                    let origin = vec2f(
 371                        bounds.origin_x(),
 372                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 373                    );
 374                    let size = vec2f(
 375                        bounds.width(),
 376                        layout.line_height * (end_row - start_row + 1) as f32,
 377                    );
 378                    cx.scene.push_quad(Quad {
 379                        bounds: RectF::new(origin, size),
 380                        background: Some(self.style.active_line_background),
 381                        border: Border::default(),
 382                        corner_radius: 0.,
 383                    });
 384                }
 385            }
 386
 387            if let Some(highlighted_rows) = &layout.highlighted_rows {
 388                let origin = vec2f(
 389                    bounds.origin_x(),
 390                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 391                        - scroll_top,
 392                );
 393                let size = vec2f(
 394                    bounds.width(),
 395                    layout.line_height * highlighted_rows.len() as f32,
 396                );
 397                cx.scene.push_quad(Quad {
 398                    bounds: RectF::new(origin, size),
 399                    background: Some(self.style.highlighted_line_background),
 400                    border: Border::default(),
 401                    corner_radius: 0.,
 402                });
 403            }
 404        }
 405    }
 406
 407    fn paint_gutter(
 408        &mut self,
 409        bounds: RectF,
 410        visible_bounds: RectF,
 411        layout: &mut LayoutState,
 412        cx: &mut PaintContext,
 413    ) {
 414        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 415        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 416            if let Some(line) = line {
 417                let line_origin = bounds.origin()
 418                    + vec2f(
 419                        bounds.width() - line.width() - layout.gutter_padding,
 420                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 421                    );
 422                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 423            }
 424        }
 425
 426        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 427            let mut x = bounds.width() - layout.gutter_padding;
 428            let mut y = *row as f32 * layout.line_height - scroll_top;
 429            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 430            y += (layout.line_height - indicator.size().y()) / 2.;
 431            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 432        }
 433    }
 434
 435    fn paint_text(
 436        &mut self,
 437        bounds: RectF,
 438        visible_bounds: RectF,
 439        layout: &mut LayoutState,
 440        paint: &mut PaintState,
 441        cx: &mut PaintContext,
 442    ) {
 443        let view = self.view(cx.app);
 444        let style = &self.style;
 445        let local_replica_id = view.replica_id(cx);
 446        let scroll_position = layout.snapshot.scroll_position();
 447        let start_row = scroll_position.y() as u32;
 448        let scroll_top = scroll_position.y() * layout.line_height;
 449        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 450        let max_glyph_width = layout.em_width;
 451        let scroll_left = scroll_position.x() * max_glyph_width;
 452        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 453
 454        cx.scene.push_layer(Some(bounds));
 455
 456        cx.scene.push_cursor_region(CursorRegion {
 457            bounds,
 458            style: if !view.link_go_to_definition_state.definitions.is_empty() {
 459                CursorStyle::PointingHand
 460            } else {
 461                CursorStyle::IBeam
 462            },
 463        });
 464
 465        for (range, color) in &layout.highlighted_ranges {
 466            self.paint_highlighted_range(
 467                range.clone(),
 468                start_row,
 469                end_row,
 470                *color,
 471                0.,
 472                0.15 * layout.line_height,
 473                layout,
 474                content_origin,
 475                scroll_top,
 476                scroll_left,
 477                bounds,
 478                cx,
 479            );
 480        }
 481
 482        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 483        for (replica_id, selections) in &layout.selections {
 484            let selection_style = style.replica_selection_style(*replica_id);
 485            let corner_radius = 0.15 * layout.line_height;
 486
 487            for selection in selections {
 488                self.paint_highlighted_range(
 489                    selection.range.clone(),
 490                    start_row,
 491                    end_row,
 492                    selection_style.selection,
 493                    corner_radius,
 494                    corner_radius * 2.,
 495                    layout,
 496                    content_origin,
 497                    scroll_top,
 498                    scroll_left,
 499                    bounds,
 500                    cx,
 501                );
 502
 503                if view.show_local_cursors() || *replica_id != local_replica_id {
 504                    let cursor_position = selection.head;
 505                    if (start_row..end_row).contains(&cursor_position.row()) {
 506                        let cursor_row_layout =
 507                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 508                        let cursor_column = cursor_position.column() as usize;
 509
 510                        let cursor_character_x = cursor_row_layout.x_for_index(cursor_column);
 511                        let mut block_width =
 512                            cursor_row_layout.x_for_index(cursor_column + 1) - cursor_character_x;
 513                        if block_width == 0.0 {
 514                            block_width = layout.em_width;
 515                        }
 516
 517                        let block_text =
 518                            if let CursorShape::Block = self.cursor_shape {
 519                                layout.snapshot.chars_at(cursor_position).next().and_then(
 520                                    |character| {
 521                                        let font_id =
 522                                            cursor_row_layout.font_for_index(cursor_column)?;
 523                                        let text = character.to_string();
 524
 525                                        Some(cx.text_layout_cache.layout_str(
 526                                            &text,
 527                                            cursor_row_layout.font_size(),
 528                                            &[(
 529                                                text.len(),
 530                                                RunStyle {
 531                                                    font_id,
 532                                                    color: style.background,
 533                                                    underline: Default::default(),
 534                                                },
 535                                            )],
 536                                        ))
 537                                    },
 538                                )
 539                            } else {
 540                                None
 541                            };
 542
 543                        let x = cursor_character_x - scroll_left;
 544                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 545                        cursors.push(Cursor {
 546                            color: selection_style.cursor,
 547                            block_width,
 548                            origin: vec2f(x, y),
 549                            line_height: layout.line_height,
 550                            shape: self.cursor_shape,
 551                            block_text,
 552                        });
 553                    }
 554                }
 555            }
 556        }
 557
 558        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 559            // Draw glyphs
 560            for (ix, line) in layout.line_layouts.iter().enumerate() {
 561                let row = start_row + ix as u32;
 562                line.paint(
 563                    content_origin
 564                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 565                    visible_text_bounds,
 566                    layout.line_height,
 567                    cx,
 568                );
 569            }
 570        }
 571
 572        cx.scene.push_layer(Some(bounds));
 573        for cursor in cursors {
 574            cursor.paint(content_origin, cx);
 575        }
 576        cx.scene.pop_layer();
 577
 578        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 579            cx.scene.push_stacking_context(None);
 580            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 581            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 582            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 583            let mut list_origin = content_origin + vec2f(x, y);
 584            let list_width = context_menu.size().x();
 585            let list_height = context_menu.size().y();
 586
 587            // Snap the right edge of the list to the right edge of the window if
 588            // its horizontal bounds overflow.
 589            if list_origin.x() + list_width > cx.window_size.x() {
 590                list_origin.set_x((cx.window_size.x() - list_width).max(0.));
 591            }
 592
 593            if list_origin.y() + list_height > bounds.max_y() {
 594                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 595            }
 596
 597            context_menu.paint(
 598                list_origin,
 599                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 600                cx,
 601            );
 602
 603            paint.context_menu_bounds = Some(RectF::new(list_origin, context_menu.size()));
 604
 605            cx.scene.pop_stacking_context();
 606        }
 607
 608        if let Some((position, hover_popovers)) = layout.hover_popovers.as_mut() {
 609            cx.scene.push_stacking_context(None);
 610
 611            // This is safe because we check on layout whether the required row is available
 612            let hovered_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 613
 614            // Minimum required size: Take the first popover, and add 1.5 times the minimum popover
 615            // height. This is the size we will use to decide whether to render popovers above or below
 616            // the hovered line.
 617            let first_size = hover_popovers[0].size();
 618            let height_to_reserve =
 619                first_size.y() + 1.5 * MIN_POPOVER_LINE_HEIGHT as f32 * layout.line_height;
 620
 621            // Compute Hovered Point
 622            let x = hovered_row_layout.x_for_index(position.column() as usize) - scroll_left;
 623            let y = position.row() as f32 * layout.line_height - scroll_top;
 624            let hovered_point = content_origin + vec2f(x, y);
 625
 626            paint.hover_popover_bounds.clear();
 627
 628            if hovered_point.y() - height_to_reserve > 0.0 {
 629                // There is enough space above. Render popovers above the hovered point
 630                let mut current_y = hovered_point.y();
 631                for hover_popover in hover_popovers {
 632                    let size = hover_popover.size();
 633                    let mut popover_origin = vec2f(hovered_point.x(), current_y - size.y());
 634
 635                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 636                    if x_out_of_bounds < 0.0 {
 637                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 638                    }
 639
 640                    hover_popover.paint(
 641                        popover_origin,
 642                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 643                        cx,
 644                    );
 645
 646                    paint.hover_popover_bounds.push(
 647                        RectF::new(popover_origin, hover_popover.size())
 648                            .dilate(Vector2F::new(0., 5.)),
 649                    );
 650
 651                    current_y = popover_origin.y() - HOVER_POPOVER_GAP;
 652                }
 653            } else {
 654                // There is not enough space above. Render popovers below the hovered point
 655                let mut current_y = hovered_point.y() + layout.line_height;
 656                for hover_popover in hover_popovers {
 657                    let size = hover_popover.size();
 658                    let mut popover_origin = vec2f(hovered_point.x(), current_y);
 659
 660                    let x_out_of_bounds = bounds.max_x() - (popover_origin.x() + size.x());
 661                    if x_out_of_bounds < 0.0 {
 662                        popover_origin.set_x(popover_origin.x() + x_out_of_bounds);
 663                    }
 664
 665                    hover_popover.paint(
 666                        popover_origin,
 667                        RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 668                        cx,
 669                    );
 670
 671                    paint.hover_popover_bounds.push(
 672                        RectF::new(popover_origin, hover_popover.size())
 673                            .dilate(Vector2F::new(0., 5.)),
 674                    );
 675
 676                    current_y = popover_origin.y() + size.y() + HOVER_POPOVER_GAP;
 677                }
 678            }
 679
 680            cx.scene.pop_stacking_context();
 681        }
 682
 683        cx.scene.pop_layer();
 684    }
 685
 686    fn paint_highlighted_range(
 687        &self,
 688        range: Range<DisplayPoint>,
 689        start_row: u32,
 690        end_row: u32,
 691        color: Color,
 692        corner_radius: f32,
 693        line_end_overshoot: f32,
 694        layout: &LayoutState,
 695        content_origin: Vector2F,
 696        scroll_top: f32,
 697        scroll_left: f32,
 698        bounds: RectF,
 699        cx: &mut PaintContext,
 700    ) {
 701        if range.start != range.end {
 702            let row_range = if range.end.column() == 0 {
 703                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 704            } else {
 705                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 706            };
 707
 708            let highlighted_range = HighlightedRange {
 709                color,
 710                line_height: layout.line_height,
 711                corner_radius,
 712                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 713                    - scroll_top,
 714                lines: row_range
 715                    .into_iter()
 716                    .map(|row| {
 717                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 718                        HighlightedRangeLine {
 719                            start_x: if row == range.start.row() {
 720                                content_origin.x()
 721                                    + line_layout.x_for_index(range.start.column() as usize)
 722                                    - scroll_left
 723                            } else {
 724                                content_origin.x() - scroll_left
 725                            },
 726                            end_x: if row == range.end.row() {
 727                                content_origin.x()
 728                                    + line_layout.x_for_index(range.end.column() as usize)
 729                                    - scroll_left
 730                            } else {
 731                                content_origin.x() + line_layout.width() + line_end_overshoot
 732                                    - scroll_left
 733                            },
 734                        }
 735                    })
 736                    .collect(),
 737            };
 738
 739            highlighted_range.paint(bounds, cx.scene);
 740        }
 741    }
 742
 743    fn paint_blocks(
 744        &mut self,
 745        bounds: RectF,
 746        visible_bounds: RectF,
 747        layout: &mut LayoutState,
 748        cx: &mut PaintContext,
 749    ) {
 750        let scroll_position = layout.snapshot.scroll_position();
 751        let scroll_left = scroll_position.x() * layout.em_width;
 752        let scroll_top = scroll_position.y() * layout.line_height;
 753
 754        for block in &mut layout.blocks {
 755            let mut origin =
 756                bounds.origin() + vec2f(0., block.row as f32 * layout.line_height - scroll_top);
 757            if !matches!(block.style, BlockStyle::Sticky) {
 758                origin += vec2f(-scroll_left, 0.);
 759            }
 760            block.element.paint(origin, visible_bounds, cx);
 761        }
 762    }
 763
 764    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 765        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 766        let style = &self.style;
 767
 768        cx.text_layout_cache
 769            .layout_str(
 770                "1".repeat(digit_count).as_str(),
 771                style.text.font_size,
 772                &[(
 773                    digit_count,
 774                    RunStyle {
 775                        font_id: style.text.font_id,
 776                        color: Color::black(),
 777                        underline: Default::default(),
 778                    },
 779                )],
 780            )
 781            .width()
 782    }
 783
 784    fn layout_line_numbers(
 785        &self,
 786        rows: Range<u32>,
 787        active_rows: &BTreeMap<u32, bool>,
 788        snapshot: &EditorSnapshot,
 789        cx: &LayoutContext,
 790    ) -> Vec<Option<text_layout::Line>> {
 791        let style = &self.style;
 792        let include_line_numbers = snapshot.mode == EditorMode::Full;
 793        let mut line_number_layouts = Vec::with_capacity(rows.len());
 794        let mut line_number = String::new();
 795        for (ix, row) in snapshot
 796            .buffer_rows(rows.start)
 797            .take((rows.end - rows.start) as usize)
 798            .enumerate()
 799        {
 800            let display_row = rows.start + ix as u32;
 801            let color = if active_rows.contains_key(&display_row) {
 802                style.line_number_active
 803            } else {
 804                style.line_number
 805            };
 806            if let Some(buffer_row) = row {
 807                if include_line_numbers {
 808                    line_number.clear();
 809                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 810                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 811                        &line_number,
 812                        style.text.font_size,
 813                        &[(
 814                            line_number.len(),
 815                            RunStyle {
 816                                font_id: style.text.font_id,
 817                                color,
 818                                underline: Default::default(),
 819                            },
 820                        )],
 821                    )));
 822                }
 823            } else {
 824                line_number_layouts.push(None);
 825            }
 826        }
 827
 828        line_number_layouts
 829    }
 830
 831    fn layout_lines(
 832        &mut self,
 833        rows: Range<u32>,
 834        snapshot: &EditorSnapshot,
 835        cx: &LayoutContext,
 836    ) -> Vec<text_layout::Line> {
 837        if rows.start >= rows.end {
 838            return Vec::new();
 839        }
 840
 841        // When the editor is empty and unfocused, then show the placeholder.
 842        if snapshot.is_empty() && !snapshot.is_focused() {
 843            let placeholder_style = self
 844                .style
 845                .placeholder_text
 846                .as_ref()
 847                .unwrap_or_else(|| &self.style.text);
 848            let placeholder_text = snapshot.placeholder_text();
 849            let placeholder_lines = placeholder_text
 850                .as_ref()
 851                .map_or("", AsRef::as_ref)
 852                .split('\n')
 853                .skip(rows.start as usize)
 854                .chain(iter::repeat(""))
 855                .take(rows.len());
 856            return placeholder_lines
 857                .map(|line| {
 858                    cx.text_layout_cache.layout_str(
 859                        line,
 860                        placeholder_style.font_size,
 861                        &[(
 862                            line.len(),
 863                            RunStyle {
 864                                font_id: placeholder_style.font_id,
 865                                color: placeholder_style.color,
 866                                underline: Default::default(),
 867                            },
 868                        )],
 869                    )
 870                })
 871                .collect();
 872        } else {
 873            let style = &self.style;
 874            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 875                let mut highlight_style = chunk
 876                    .syntax_highlight_id
 877                    .and_then(|id| id.style(&style.syntax));
 878
 879                if let Some(chunk_highlight) = chunk.highlight_style {
 880                    if let Some(highlight_style) = highlight_style.as_mut() {
 881                        highlight_style.highlight(chunk_highlight);
 882                    } else {
 883                        highlight_style = Some(chunk_highlight);
 884                    }
 885                }
 886
 887                let mut diagnostic_highlight = HighlightStyle::default();
 888
 889                if chunk.is_unnecessary {
 890                    diagnostic_highlight.fade_out = Some(style.unnecessary_code_fade);
 891                }
 892
 893                if let Some(severity) = chunk.diagnostic_severity {
 894                    // Omit underlines for HINT/INFO diagnostics on 'unnecessary' code.
 895                    if severity <= DiagnosticSeverity::WARNING || !chunk.is_unnecessary {
 896                        let diagnostic_style = super::diagnostic_style(severity, true, style);
 897                        diagnostic_highlight.underline = Some(Underline {
 898                            color: Some(diagnostic_style.message.text.color),
 899                            thickness: 1.0.into(),
 900                            squiggly: true,
 901                        });
 902                    }
 903                }
 904
 905                if let Some(highlight_style) = highlight_style.as_mut() {
 906                    highlight_style.highlight(diagnostic_highlight);
 907                } else {
 908                    highlight_style = Some(diagnostic_highlight);
 909                }
 910
 911                (chunk.text, highlight_style)
 912            });
 913            layout_highlighted_chunks(
 914                chunks,
 915                &style.text,
 916                &cx.text_layout_cache,
 917                &cx.font_cache,
 918                MAX_LINE_LEN,
 919                rows.len() as usize,
 920            )
 921        }
 922    }
 923
 924    fn layout_blocks(
 925        &mut self,
 926        rows: Range<u32>,
 927        snapshot: &EditorSnapshot,
 928        editor_width: f32,
 929        scroll_width: f32,
 930        gutter_padding: f32,
 931        gutter_width: f32,
 932        em_width: f32,
 933        text_x: f32,
 934        line_height: f32,
 935        style: &EditorStyle,
 936        line_layouts: &[text_layout::Line],
 937        cx: &mut LayoutContext,
 938    ) -> (f32, Vec<BlockLayout>) {
 939        let editor = if let Some(editor) = self.view.upgrade(cx) {
 940            editor
 941        } else {
 942            return Default::default();
 943        };
 944
 945        let tooltip_style = cx.global::<Settings>().theme.tooltip.clone();
 946        let scroll_x = snapshot.scroll_position.x();
 947        let (fixed_blocks, non_fixed_blocks) = snapshot
 948            .blocks_in_range(rows.clone())
 949            .partition::<Vec<_>, _>(|(_, block)| match block {
 950                TransformBlock::ExcerptHeader { .. } => false,
 951                TransformBlock::Custom(block) => block.style() == BlockStyle::Fixed,
 952            });
 953        let mut render_block = |block: &TransformBlock, width: f32| {
 954            let mut element = match block {
 955                TransformBlock::Custom(block) => {
 956                    let align_to = block
 957                        .position()
 958                        .to_point(&snapshot.buffer_snapshot)
 959                        .to_display_point(snapshot);
 960                    let anchor_x = text_x
 961                        + if rows.contains(&align_to.row()) {
 962                            line_layouts[(align_to.row() - rows.start) as usize]
 963                                .x_for_index(align_to.column() as usize)
 964                        } else {
 965                            layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 966                                .x_for_index(align_to.column() as usize)
 967                        };
 968
 969                    cx.render(&editor, |_, cx| {
 970                        block.render(&mut BlockContext {
 971                            cx,
 972                            anchor_x,
 973                            gutter_padding,
 974                            line_height,
 975                            scroll_x,
 976                            gutter_width,
 977                            em_width,
 978                        })
 979                    })
 980                }
 981                TransformBlock::ExcerptHeader {
 982                    key,
 983                    buffer,
 984                    range,
 985                    starts_new_buffer,
 986                    ..
 987                } => {
 988                    let jump_icon = project::File::from_dyn(buffer.file()).map(|file| {
 989                        let jump_position = range
 990                            .primary
 991                            .as_ref()
 992                            .map_or(range.context.start, |primary| primary.start);
 993                        let jump_action = crate::Jump {
 994                            path: ProjectPath {
 995                                worktree_id: file.worktree_id(cx),
 996                                path: file.path.clone(),
 997                            },
 998                            position: language::ToPoint::to_point(&jump_position, buffer),
 999                            anchor: jump_position,
1000                        };
1001
1002                        enum JumpIcon {}
1003                        cx.render(&editor, |_, cx| {
1004                            MouseEventHandler::new::<JumpIcon, _, _>(*key, cx, |state, _| {
1005                                let style = style.jump_icon.style_for(state, false);
1006                                Svg::new("icons/arrow_up_right_8.svg")
1007                                    .with_color(style.color)
1008                                    .constrained()
1009                                    .with_width(style.icon_width)
1010                                    .aligned()
1011                                    .contained()
1012                                    .with_style(style.container)
1013                                    .constrained()
1014                                    .with_width(style.button_width)
1015                                    .with_height(style.button_width)
1016                                    .boxed()
1017                            })
1018                            .with_cursor_style(CursorStyle::PointingHand)
1019                            .on_click(MouseButton::Left, move |_, cx| {
1020                                cx.dispatch_action(jump_action.clone())
1021                            })
1022                            .with_tooltip::<JumpIcon, _>(
1023                                *key,
1024                                "Jump to Buffer".to_string(),
1025                                Some(Box::new(crate::OpenExcerpts)),
1026                                tooltip_style.clone(),
1027                                cx,
1028                            )
1029                            .aligned()
1030                            .flex_float()
1031                            .boxed()
1032                        })
1033                    });
1034
1035                    if *starts_new_buffer {
1036                        let style = &self.style.diagnostic_path_header;
1037                        let font_size =
1038                            (style.text_scale_factor * self.style.text.font_size).round();
1039
1040                        let mut filename = None;
1041                        let mut parent_path = None;
1042                        if let Some(file) = buffer.file() {
1043                            let path = file.path();
1044                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
1045                            parent_path =
1046                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
1047                        }
1048
1049                        Flex::row()
1050                            .with_child(
1051                                Label::new(
1052                                    filename.unwrap_or_else(|| "untitled".to_string()),
1053                                    style.filename.text.clone().with_font_size(font_size),
1054                                )
1055                                .contained()
1056                                .with_style(style.filename.container)
1057                                .aligned()
1058                                .boxed(),
1059                            )
1060                            .with_children(parent_path.map(|path| {
1061                                Label::new(path, style.path.text.clone().with_font_size(font_size))
1062                                    .contained()
1063                                    .with_style(style.path.container)
1064                                    .aligned()
1065                                    .boxed()
1066                            }))
1067                            .with_children(jump_icon)
1068                            .contained()
1069                            .with_style(style.container)
1070                            .with_padding_left(gutter_padding)
1071                            .with_padding_right(gutter_padding)
1072                            .expanded()
1073                            .named("path header block")
1074                    } else {
1075                        let text_style = self.style.text.clone();
1076                        Flex::row()
1077                            .with_child(Label::new("".to_string(), text_style).boxed())
1078                            .with_children(jump_icon)
1079                            .contained()
1080                            .with_padding_left(gutter_padding)
1081                            .with_padding_right(gutter_padding)
1082                            .expanded()
1083                            .named("collapsed context")
1084                    }
1085                }
1086            };
1087
1088            element.layout(
1089                SizeConstraint {
1090                    min: Vector2F::zero(),
1091                    max: vec2f(width, block.height() as f32 * line_height),
1092                },
1093                cx,
1094            );
1095            element
1096        };
1097
1098        let mut fixed_block_max_width = 0f32;
1099        let mut blocks = Vec::new();
1100        for (row, block) in fixed_blocks {
1101            let element = render_block(block, f32::INFINITY);
1102            fixed_block_max_width = fixed_block_max_width.max(element.size().x() + em_width);
1103            blocks.push(BlockLayout {
1104                row,
1105                element,
1106                style: BlockStyle::Fixed,
1107            });
1108        }
1109        for (row, block) in non_fixed_blocks {
1110            let style = match block {
1111                TransformBlock::Custom(block) => block.style(),
1112                TransformBlock::ExcerptHeader { .. } => BlockStyle::Sticky,
1113            };
1114            let width = match style {
1115                BlockStyle::Sticky => editor_width,
1116                BlockStyle::Flex => editor_width
1117                    .max(fixed_block_max_width)
1118                    .max(gutter_width + scroll_width),
1119                BlockStyle::Fixed => unreachable!(),
1120            };
1121            let element = render_block(block, width);
1122            blocks.push(BlockLayout {
1123                row,
1124                element,
1125                style,
1126            });
1127        }
1128        (
1129            scroll_width.max(fixed_block_max_width - gutter_width),
1130            blocks,
1131        )
1132    }
1133}
1134
1135impl Element for EditorElement {
1136    type LayoutState = LayoutState;
1137    type PaintState = PaintState;
1138
1139    fn layout(
1140        &mut self,
1141        constraint: SizeConstraint,
1142        cx: &mut LayoutContext,
1143    ) -> (Vector2F, Self::LayoutState) {
1144        let mut size = constraint.max;
1145        if size.x().is_infinite() {
1146            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
1147        }
1148
1149        let snapshot = self.snapshot(cx.app);
1150        let style = self.style.clone();
1151        let line_height = style.text.line_height(cx.font_cache);
1152
1153        let gutter_padding;
1154        let gutter_width;
1155        let gutter_margin;
1156        if snapshot.mode == EditorMode::Full {
1157            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
1158            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
1159            gutter_margin = -style.text.descent(cx.font_cache);
1160        } else {
1161            gutter_padding = 0.0;
1162            gutter_width = 0.0;
1163            gutter_margin = 0.0;
1164        };
1165
1166        let text_width = size.x() - gutter_width;
1167        let em_width = style.text.em_width(cx.font_cache);
1168        let em_advance = style.text.em_advance(cx.font_cache);
1169        let overscroll = vec2f(em_width, 0.);
1170        let snapshot = self.update_view(cx.app, |view, cx| {
1171            let wrap_width = match view.soft_wrap_mode(cx) {
1172                SoftWrap::None => Some((MAX_LINE_LEN / 2) as f32 * em_advance),
1173                SoftWrap::EditorWidth => {
1174                    Some(text_width - gutter_margin - overscroll.x() - em_width)
1175                }
1176                SoftWrap::Column(column) => Some(column as f32 * em_advance),
1177            };
1178
1179            if view.set_wrap_width(wrap_width, cx) {
1180                view.snapshot(cx)
1181            } else {
1182                snapshot
1183            }
1184        });
1185
1186        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
1187        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
1188            size.set_y(
1189                scroll_height
1190                    .min(constraint.max_along(Axis::Vertical))
1191                    .max(constraint.min_along(Axis::Vertical))
1192                    .min(line_height * max_lines as f32),
1193            )
1194        } else if let EditorMode::SingleLine = snapshot.mode {
1195            size.set_y(
1196                line_height
1197                    .min(constraint.max_along(Axis::Vertical))
1198                    .max(constraint.min_along(Axis::Vertical)),
1199            )
1200        } else if size.y().is_infinite() {
1201            size.set_y(scroll_height);
1202        }
1203        let gutter_size = vec2f(gutter_width, size.y());
1204        let text_size = vec2f(text_width, size.y());
1205
1206        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
1207            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
1208            let snapshot = view.snapshot(cx);
1209            (autoscroll_horizontally, snapshot)
1210        });
1211
1212        let scroll_position = snapshot.scroll_position();
1213        // The scroll position is a fractional point, the whole number of which represents
1214        // the top of the window in terms of display rows.
1215        let start_row = scroll_position.y() as u32;
1216        let scroll_top = scroll_position.y() * line_height;
1217
1218        // Add 1 to ensure selections bleed off screen
1219        let end_row = 1 + cmp::min(
1220            ((scroll_top + size.y()) / line_height).ceil() as u32,
1221            snapshot.max_point().row(),
1222        );
1223
1224        let start_anchor = if start_row == 0 {
1225            Anchor::min()
1226        } else {
1227            snapshot
1228                .buffer_snapshot
1229                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
1230        };
1231        let end_anchor = if end_row > snapshot.max_point().row() {
1232            Anchor::max()
1233        } else {
1234            snapshot
1235                .buffer_snapshot
1236                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
1237        };
1238
1239        let mut selections: Vec<(ReplicaId, Vec<SelectionLayout>)> = Vec::new();
1240        let mut active_rows = BTreeMap::new();
1241        let mut highlighted_rows = None;
1242        let mut highlighted_ranges = Vec::new();
1243        self.update_view(cx.app, |view, cx| {
1244            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
1245
1246            highlighted_rows = view.highlighted_rows();
1247            let theme = cx.global::<Settings>().theme.as_ref();
1248            highlighted_ranges = view.background_highlights_in_range(
1249                start_anchor.clone()..end_anchor.clone(),
1250                &display_map,
1251                theme,
1252            );
1253
1254            let mut remote_selections = HashMap::default();
1255            for (replica_id, line_mode, selection) in display_map
1256                .buffer_snapshot
1257                .remote_selections_in_range(&(start_anchor.clone()..end_anchor.clone()))
1258            {
1259                // The local selections match the leader's selections.
1260                if Some(replica_id) == view.leader_replica_id {
1261                    continue;
1262                }
1263                remote_selections
1264                    .entry(replica_id)
1265                    .or_insert(Vec::new())
1266                    .push(SelectionLayout::new(selection, line_mode, &display_map));
1267            }
1268            selections.extend(remote_selections);
1269
1270            if view.show_local_selections {
1271                let mut local_selections = view
1272                    .selections
1273                    .disjoint_in_range(start_anchor..end_anchor, cx);
1274                local_selections.extend(view.selections.pending(cx));
1275                for selection in &local_selections {
1276                    let is_empty = selection.start == selection.end;
1277                    let selection_start = snapshot.prev_line_boundary(selection.start).1;
1278                    let selection_end = snapshot.next_line_boundary(selection.end).1;
1279                    for row in cmp::max(selection_start.row(), start_row)
1280                        ..=cmp::min(selection_end.row(), end_row)
1281                    {
1282                        let contains_non_empty_selection =
1283                            active_rows.entry(row).or_insert(!is_empty);
1284                        *contains_non_empty_selection |= !is_empty;
1285                    }
1286                }
1287
1288                // Render the local selections in the leader's color when following.
1289                let local_replica_id = view.leader_replica_id.unwrap_or(view.replica_id(cx));
1290
1291                selections.push((
1292                    local_replica_id,
1293                    local_selections
1294                        .into_iter()
1295                        .map(|selection| {
1296                            SelectionLayout::new(selection, view.selections.line_mode, &display_map)
1297                        })
1298                        .collect(),
1299                ));
1300            }
1301        });
1302
1303        let line_number_layouts =
1304            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
1305
1306        let mut max_visible_line_width = 0.0;
1307        let line_layouts = self.layout_lines(start_row..end_row, &snapshot, cx);
1308        for line in &line_layouts {
1309            if line.width() > max_visible_line_width {
1310                max_visible_line_width = line.width();
1311            }
1312        }
1313
1314        let style = self.style.clone();
1315        let longest_line_width = layout_line(
1316            snapshot.longest_row(),
1317            &snapshot,
1318            &style,
1319            cx.text_layout_cache,
1320        )
1321        .width();
1322        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
1323        let em_width = style.text.em_width(cx.font_cache);
1324        let (scroll_width, blocks) = self.layout_blocks(
1325            start_row..end_row,
1326            &snapshot,
1327            size.x(),
1328            scroll_width,
1329            gutter_padding,
1330            gutter_width,
1331            em_width,
1332            gutter_width + gutter_margin,
1333            line_height,
1334            &style,
1335            &line_layouts,
1336            cx,
1337        );
1338
1339        let max_row = snapshot.max_point().row();
1340        let scroll_max = vec2f(
1341            ((scroll_width - text_size.x()) / em_width).max(0.0),
1342            max_row.saturating_sub(1) as f32,
1343        );
1344
1345        self.update_view(cx.app, |view, cx| {
1346            let clamped = view.clamp_scroll_left(scroll_max.x());
1347            let autoscrolled;
1348            if autoscroll_horizontally {
1349                autoscrolled = view.autoscroll_horizontally(
1350                    start_row,
1351                    text_size.x(),
1352                    scroll_width,
1353                    em_width,
1354                    &line_layouts,
1355                    cx,
1356                );
1357            } else {
1358                autoscrolled = false;
1359            }
1360
1361            if clamped || autoscrolled {
1362                snapshot = view.snapshot(cx);
1363            }
1364        });
1365
1366        let mut context_menu = None;
1367        let mut code_actions_indicator = None;
1368        let mut hover = None;
1369        cx.render(&self.view.upgrade(cx).unwrap(), |view, cx| {
1370            let newest_selection_head = view
1371                .selections
1372                .newest::<usize>(cx)
1373                .head()
1374                .to_display_point(&snapshot);
1375
1376            let style = view.style(cx);
1377            if (start_row..end_row).contains(&newest_selection_head.row()) {
1378                if view.context_menu_visible() {
1379                    context_menu =
1380                        view.render_context_menu(newest_selection_head, style.clone(), cx);
1381                }
1382
1383                code_actions_indicator = view
1384                    .render_code_actions_indicator(&style, cx)
1385                    .map(|indicator| (newest_selection_head.row(), indicator));
1386            }
1387
1388            let visible_rows = start_row..start_row + line_layouts.len() as u32;
1389            hover = view.hover_state.render(&snapshot, &style, visible_rows, cx);
1390        });
1391
1392        if let Some((_, context_menu)) = context_menu.as_mut() {
1393            context_menu.layout(
1394                SizeConstraint {
1395                    min: Vector2F::zero(),
1396                    max: vec2f(
1397                        cx.window_size.x() * 0.7,
1398                        (12. * line_height).min((size.y() - line_height) / 2.),
1399                    ),
1400                },
1401                cx,
1402            );
1403        }
1404
1405        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
1406            indicator.layout(
1407                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
1408                cx,
1409            );
1410        }
1411
1412        if let Some((_, hover_popovers)) = hover.as_mut() {
1413            for hover_popover in hover_popovers.iter_mut() {
1414                hover_popover.layout(
1415                    SizeConstraint {
1416                        min: Vector2F::zero(),
1417                        max: vec2f(
1418                            (120. * em_width) // Default size
1419                                .min(size.x() / 2.) // Shrink to half of the editor width
1420                                .max(MIN_POPOVER_CHARACTER_WIDTH * em_width), // Apply minimum width of 20 characters
1421                            (16. * line_height) // Default size
1422                                .min(size.y() / 2.) // Shrink to half of the editor height
1423                                .max(MIN_POPOVER_LINE_HEIGHT * line_height), // Apply minimum height of 4 lines
1424                        ),
1425                    },
1426                    cx,
1427                );
1428            }
1429        }
1430
1431        (
1432            size,
1433            LayoutState {
1434                size,
1435                scroll_max,
1436                gutter_size,
1437                gutter_padding,
1438                text_size,
1439                gutter_margin,
1440                snapshot,
1441                active_rows,
1442                highlighted_rows,
1443                highlighted_ranges,
1444                line_layouts,
1445                line_number_layouts,
1446                blocks,
1447                line_height,
1448                em_width,
1449                em_advance,
1450                selections,
1451                context_menu,
1452                code_actions_indicator,
1453                hover_popovers: hover,
1454            },
1455        )
1456    }
1457
1458    fn paint(
1459        &mut self,
1460        bounds: RectF,
1461        visible_bounds: RectF,
1462        layout: &mut Self::LayoutState,
1463        cx: &mut PaintContext,
1464    ) -> Self::PaintState {
1465        cx.scene.push_layer(Some(bounds));
1466
1467        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1468        let text_bounds = RectF::new(
1469            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1470            layout.text_size,
1471        );
1472
1473        let mut paint_state = PaintState {
1474            bounds,
1475            gutter_bounds,
1476            text_bounds,
1477            context_menu_bounds: None,
1478            hover_popover_bounds: Default::default(),
1479        };
1480
1481        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1482        if layout.gutter_size.x() > 0. {
1483            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1484        }
1485        self.paint_text(text_bounds, visible_bounds, layout, &mut paint_state, cx);
1486
1487        if !layout.blocks.is_empty() {
1488            cx.scene.push_layer(Some(bounds));
1489            self.paint_blocks(bounds, visible_bounds, layout, cx);
1490            cx.scene.pop_layer();
1491        }
1492
1493        cx.scene.pop_layer();
1494
1495        paint_state
1496    }
1497
1498    fn dispatch_event(
1499        &mut self,
1500        event: &Event,
1501        _: RectF,
1502        _: RectF,
1503        layout: &mut LayoutState,
1504        paint: &mut PaintState,
1505        cx: &mut EventContext,
1506    ) -> bool {
1507        if let Some((_, context_menu)) = &mut layout.context_menu {
1508            if context_menu.dispatch_event(event, cx) {
1509                return true;
1510            }
1511        }
1512
1513        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1514            if indicator.dispatch_event(event, cx) {
1515                return true;
1516            }
1517        }
1518
1519        if let Some((_, popover_elements)) = &mut layout.hover_popovers {
1520            for popover_element in popover_elements.iter_mut() {
1521                if popover_element.dispatch_event(event, cx) {
1522                    return true;
1523                }
1524            }
1525        }
1526
1527        for block in &mut layout.blocks {
1528            if block.element.dispatch_event(event, cx) {
1529                return true;
1530            }
1531        }
1532
1533        match event {
1534            Event::MouseDown(MouseButtonEvent {
1535                button: MouseButton::Left,
1536                position,
1537                cmd,
1538                alt,
1539                shift,
1540                click_count,
1541                ..
1542            }) => self.mouse_down(
1543                *position,
1544                *cmd,
1545                *alt,
1546                *shift,
1547                *click_count,
1548                layout,
1549                paint,
1550                cx,
1551            ),
1552
1553            Event::MouseDown(MouseButtonEvent {
1554                button: MouseButton::Right,
1555                position,
1556                ..
1557            }) => self.mouse_right_down(*position, layout, paint, cx),
1558
1559            Event::MouseUp(MouseButtonEvent {
1560                button: MouseButton::Left,
1561                position,
1562                ..
1563            }) => self.mouse_up(*position, cx),
1564
1565            Event::MouseMoved(MouseMovedEvent {
1566                pressed_button: Some(MouseButton::Left),
1567                position,
1568                ..
1569            }) => self.mouse_dragged(*position, layout, paint, cx),
1570
1571            Event::ScrollWheel(ScrollWheelEvent {
1572                position,
1573                delta,
1574                precise,
1575            }) => self.scroll(*position, *delta, *precise, layout, paint, cx),
1576
1577            &Event::ModifiersChanged(event) => self.modifiers_changed(event, cx),
1578
1579            &Event::MouseMoved(event) => self.mouse_moved(event, layout, paint, cx),
1580
1581            _ => false,
1582        }
1583    }
1584
1585    fn rect_for_text_range(
1586        &self,
1587        range_utf16: Range<usize>,
1588        bounds: RectF,
1589        _: RectF,
1590        layout: &Self::LayoutState,
1591        _: &Self::PaintState,
1592        _: &gpui::MeasurementContext,
1593    ) -> Option<RectF> {
1594        let text_bounds = RectF::new(
1595            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1596            layout.text_size,
1597        );
1598        let content_origin = text_bounds.origin() + vec2f(layout.gutter_margin, 0.);
1599        let scroll_position = layout.snapshot.scroll_position();
1600        let start_row = scroll_position.y() as u32;
1601        let scroll_top = scroll_position.y() * layout.line_height;
1602        let scroll_left = scroll_position.x() * layout.em_width;
1603
1604        let range_start =
1605            OffsetUtf16(range_utf16.start).to_display_point(&layout.snapshot.display_snapshot);
1606        if range_start.row() < start_row {
1607            return None;
1608        }
1609
1610        let line = layout
1611            .line_layouts
1612            .get((range_start.row() - start_row) as usize)?;
1613        let range_start_x = line.x_for_index(range_start.column() as usize);
1614        let range_start_y = range_start.row() as f32 * layout.line_height;
1615        Some(RectF::new(
1616            content_origin + vec2f(range_start_x, range_start_y + layout.line_height)
1617                - vec2f(scroll_left, scroll_top),
1618            vec2f(layout.em_width, layout.line_height),
1619        ))
1620    }
1621
1622    fn debug(
1623        &self,
1624        bounds: RectF,
1625        _: &Self::LayoutState,
1626        _: &Self::PaintState,
1627        _: &gpui::DebugContext,
1628    ) -> json::Value {
1629        json!({
1630            "type": "BufferElement",
1631            "bounds": bounds.to_json()
1632        })
1633    }
1634}
1635
1636pub struct LayoutState {
1637    size: Vector2F,
1638    scroll_max: Vector2F,
1639    gutter_size: Vector2F,
1640    gutter_padding: f32,
1641    gutter_margin: f32,
1642    text_size: Vector2F,
1643    snapshot: EditorSnapshot,
1644    active_rows: BTreeMap<u32, bool>,
1645    highlighted_rows: Option<Range<u32>>,
1646    line_layouts: Vec<text_layout::Line>,
1647    line_number_layouts: Vec<Option<text_layout::Line>>,
1648    blocks: Vec<BlockLayout>,
1649    line_height: f32,
1650    em_width: f32,
1651    em_advance: f32,
1652    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1653    selections: Vec<(ReplicaId, Vec<SelectionLayout>)>,
1654    context_menu: Option<(DisplayPoint, ElementBox)>,
1655    code_actions_indicator: Option<(u32, ElementBox)>,
1656    hover_popovers: Option<(DisplayPoint, Vec<ElementBox>)>,
1657}
1658
1659struct BlockLayout {
1660    row: u32,
1661    element: ElementBox,
1662    style: BlockStyle,
1663}
1664
1665fn layout_line(
1666    row: u32,
1667    snapshot: &EditorSnapshot,
1668    style: &EditorStyle,
1669    layout_cache: &TextLayoutCache,
1670) -> text_layout::Line {
1671    let mut line = snapshot.line(row);
1672
1673    if line.len() > MAX_LINE_LEN {
1674        let mut len = MAX_LINE_LEN;
1675        while !line.is_char_boundary(len) {
1676            len -= 1;
1677        }
1678
1679        line.truncate(len);
1680    }
1681
1682    layout_cache.layout_str(
1683        &line,
1684        style.text.font_size,
1685        &[(
1686            snapshot.line_len(row) as usize,
1687            RunStyle {
1688                font_id: style.text.font_id,
1689                color: Color::black(),
1690                underline: Default::default(),
1691            },
1692        )],
1693    )
1694}
1695
1696pub struct PaintState {
1697    bounds: RectF,
1698    gutter_bounds: RectF,
1699    text_bounds: RectF,
1700    context_menu_bounds: Option<RectF>,
1701    hover_popover_bounds: Vec<RectF>,
1702}
1703
1704impl PaintState {
1705    /// Returns two display points. The first is the nearest valid
1706    /// position in the current buffer and the second is the distance to the
1707    /// nearest valid position if there was overshoot.
1708    fn point_for_position(
1709        &self,
1710        snapshot: &EditorSnapshot,
1711        layout: &LayoutState,
1712        position: Vector2F,
1713    ) -> (DisplayPoint, DisplayPoint) {
1714        let scroll_position = snapshot.scroll_position();
1715        let position = position - self.text_bounds.origin();
1716        let y = position.y().max(0.0).min(layout.size.y());
1717        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1718        let row_overshoot = row.saturating_sub(snapshot.max_point().row());
1719        let row = cmp::min(row, snapshot.max_point().row());
1720        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1721        let x = position.x() + (scroll_position.x() * layout.em_width);
1722
1723        let column = if x >= 0.0 {
1724            line.index_for_x(x)
1725                .map(|ix| ix as u32)
1726                .unwrap_or_else(|| snapshot.line_len(row))
1727        } else {
1728            0
1729        };
1730
1731        let point = snapshot.clip_point(DisplayPoint::new(row, column), Bias::Left);
1732        let mut column_overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1733        column_overshoot = column_overshoot + column - point.column();
1734
1735        (point, DisplayPoint::new(row_overshoot, column_overshoot))
1736    }
1737}
1738
1739#[derive(Copy, Clone, PartialEq, Eq, Debug)]
1740pub enum CursorShape {
1741    Bar,
1742    Block,
1743    Underscore,
1744}
1745
1746impl Default for CursorShape {
1747    fn default() -> Self {
1748        CursorShape::Bar
1749    }
1750}
1751
1752#[derive(Debug)]
1753pub struct Cursor {
1754    origin: Vector2F,
1755    block_width: f32,
1756    line_height: f32,
1757    color: Color,
1758    shape: CursorShape,
1759    block_text: Option<Line>,
1760}
1761
1762impl Cursor {
1763    pub fn new(
1764        origin: Vector2F,
1765        block_width: f32,
1766        line_height: f32,
1767        color: Color,
1768        shape: CursorShape,
1769        block_text: Option<Line>,
1770    ) -> Cursor {
1771        Cursor {
1772            origin,
1773            block_width,
1774            line_height,
1775            color,
1776            shape,
1777            block_text,
1778        }
1779    }
1780
1781    pub fn bounding_rect(&self, origin: Vector2F) -> RectF {
1782        RectF::new(
1783            self.origin + origin,
1784            vec2f(self.block_width, self.line_height),
1785        )
1786    }
1787
1788    pub fn paint(&self, origin: Vector2F, cx: &mut PaintContext) {
1789        let bounds = match self.shape {
1790            CursorShape::Bar => RectF::new(self.origin + origin, vec2f(2.0, self.line_height)),
1791            CursorShape::Block => RectF::new(
1792                self.origin + origin,
1793                vec2f(self.block_width, self.line_height),
1794            ),
1795            CursorShape::Underscore => RectF::new(
1796                self.origin + origin + Vector2F::new(0.0, self.line_height - 2.0),
1797                vec2f(self.block_width, 2.0),
1798            ),
1799        };
1800
1801        cx.scene.push_quad(Quad {
1802            bounds,
1803            background: Some(self.color),
1804            border: Border::new(0., Color::black()),
1805            corner_radius: 0.,
1806        });
1807
1808        if let Some(block_text) = &self.block_text {
1809            block_text.paint(self.origin + origin, bounds, self.line_height, cx);
1810        }
1811    }
1812}
1813
1814#[derive(Debug)]
1815pub struct HighlightedRange {
1816    pub start_y: f32,
1817    pub line_height: f32,
1818    pub lines: Vec<HighlightedRangeLine>,
1819    pub color: Color,
1820    pub corner_radius: f32,
1821}
1822
1823#[derive(Debug)]
1824pub struct HighlightedRangeLine {
1825    pub start_x: f32,
1826    pub end_x: f32,
1827}
1828
1829impl HighlightedRange {
1830    pub fn paint(&self, bounds: RectF, scene: &mut Scene) {
1831        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1832            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1833            self.paint_lines(
1834                self.start_y + self.line_height,
1835                &self.lines[1..],
1836                bounds,
1837                scene,
1838            );
1839        } else {
1840            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1841        }
1842    }
1843
1844    fn paint_lines(
1845        &self,
1846        start_y: f32,
1847        lines: &[HighlightedRangeLine],
1848        bounds: RectF,
1849        scene: &mut Scene,
1850    ) {
1851        if lines.is_empty() {
1852            return;
1853        }
1854
1855        let mut path = PathBuilder::new();
1856        let first_line = lines.first().unwrap();
1857        let last_line = lines.last().unwrap();
1858
1859        let first_top_left = vec2f(first_line.start_x, start_y);
1860        let first_top_right = vec2f(first_line.end_x, start_y);
1861
1862        let curve_height = vec2f(0., self.corner_radius);
1863        let curve_width = |start_x: f32, end_x: f32| {
1864            let max = (end_x - start_x) / 2.;
1865            let width = if max < self.corner_radius {
1866                max
1867            } else {
1868                self.corner_radius
1869            };
1870
1871            vec2f(width, 0.)
1872        };
1873
1874        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1875        path.reset(first_top_right - top_curve_width);
1876        path.curve_to(first_top_right + curve_height, first_top_right);
1877
1878        let mut iter = lines.iter().enumerate().peekable();
1879        while let Some((ix, line)) = iter.next() {
1880            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1881
1882            if let Some((_, next_line)) = iter.peek() {
1883                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1884
1885                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1886                    Ordering::Equal => {
1887                        path.line_to(bottom_right);
1888                    }
1889                    Ordering::Less => {
1890                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1891                        path.line_to(bottom_right - curve_height);
1892                        if self.corner_radius > 0. {
1893                            path.curve_to(bottom_right - curve_width, bottom_right);
1894                        }
1895                        path.line_to(next_top_right + curve_width);
1896                        if self.corner_radius > 0. {
1897                            path.curve_to(next_top_right + curve_height, next_top_right);
1898                        }
1899                    }
1900                    Ordering::Greater => {
1901                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1902                        path.line_to(bottom_right - curve_height);
1903                        if self.corner_radius > 0. {
1904                            path.curve_to(bottom_right + curve_width, bottom_right);
1905                        }
1906                        path.line_to(next_top_right - curve_width);
1907                        if self.corner_radius > 0. {
1908                            path.curve_to(next_top_right + curve_height, next_top_right);
1909                        }
1910                    }
1911                }
1912            } else {
1913                let curve_width = curve_width(line.start_x, line.end_x);
1914                path.line_to(bottom_right - curve_height);
1915                if self.corner_radius > 0. {
1916                    path.curve_to(bottom_right - curve_width, bottom_right);
1917                }
1918
1919                let bottom_left = vec2f(line.start_x, bottom_right.y());
1920                path.line_to(bottom_left + curve_width);
1921                if self.corner_radius > 0. {
1922                    path.curve_to(bottom_left - curve_height, bottom_left);
1923                }
1924            }
1925        }
1926
1927        if first_line.start_x > last_line.start_x {
1928            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1929            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1930            path.line_to(second_top_left + curve_height);
1931            if self.corner_radius > 0. {
1932                path.curve_to(second_top_left + curve_width, second_top_left);
1933            }
1934            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1935            path.line_to(first_bottom_left - curve_width);
1936            if self.corner_radius > 0. {
1937                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1938            }
1939        }
1940
1941        path.line_to(first_top_left + curve_height);
1942        if self.corner_radius > 0. {
1943            path.curve_to(first_top_left + top_curve_width, first_top_left);
1944        }
1945        path.line_to(first_top_right - top_curve_width);
1946
1947        scene.push_path(path.build(self.color, Some(bounds)));
1948    }
1949}
1950
1951fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1952    delta.powf(1.5) / 100.0
1953}
1954
1955fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1956    delta.powf(1.2) / 300.0
1957}
1958
1959#[cfg(test)]
1960mod tests {
1961    use std::sync::Arc;
1962
1963    use super::*;
1964    use crate::{
1965        display_map::{BlockDisposition, BlockProperties},
1966        Editor, MultiBuffer,
1967    };
1968    use settings::Settings;
1969    use util::test::sample_text;
1970
1971    #[gpui::test]
1972    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1973        cx.set_global(Settings::test(cx));
1974        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1975        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1976            Editor::new(EditorMode::Full, buffer, None, None, cx)
1977        });
1978        let element = EditorElement::new(
1979            editor.downgrade(),
1980            editor.read(cx).style(cx),
1981            CursorShape::Bar,
1982        );
1983
1984        let layouts = editor.update(cx, |editor, cx| {
1985            let snapshot = editor.snapshot(cx);
1986            let mut presenter = cx.build_presenter(window_id, 30.);
1987            let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
1988            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1989        });
1990        assert_eq!(layouts.len(), 6);
1991    }
1992
1993    #[gpui::test]
1994    fn test_layout_with_placeholder_text_and_blocks(cx: &mut gpui::MutableAppContext) {
1995        cx.set_global(Settings::test(cx));
1996        let buffer = MultiBuffer::build_simple("", cx);
1997        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1998            Editor::new(EditorMode::Full, buffer, None, None, cx)
1999        });
2000
2001        editor.update(cx, |editor, cx| {
2002            editor.set_placeholder_text("hello", cx);
2003            editor.insert_blocks(
2004                [BlockProperties {
2005                    style: BlockStyle::Fixed,
2006                    disposition: BlockDisposition::Above,
2007                    height: 3,
2008                    position: Anchor::min(),
2009                    render: Arc::new(|_| Empty::new().boxed()),
2010                }],
2011                cx,
2012            );
2013
2014            // Blur the editor so that it displays placeholder text.
2015            cx.blur();
2016        });
2017
2018        let mut element = EditorElement::new(
2019            editor.downgrade(),
2020            editor.read(cx).style(cx),
2021            CursorShape::Bar,
2022        );
2023
2024        let mut scene = Scene::new(1.0);
2025        let mut presenter = cx.build_presenter(window_id, 30.);
2026        let mut layout_cx = presenter.build_layout_context(Vector2F::zero(), false, cx);
2027        let (size, mut state) = element.layout(
2028            SizeConstraint::new(vec2f(500., 500.), vec2f(500., 500.)),
2029            &mut layout_cx,
2030        );
2031
2032        assert_eq!(state.line_layouts.len(), 4);
2033        assert_eq!(
2034            state
2035                .line_number_layouts
2036                .iter()
2037                .map(Option::is_some)
2038                .collect::<Vec<_>>(),
2039            &[false, false, false, true]
2040        );
2041
2042        // Don't panic.
2043        let bounds = RectF::new(Default::default(), size);
2044        let mut paint_cx = presenter.build_paint_context(&mut scene, bounds.size(), cx);
2045        element.paint(bounds, bounds, &mut state, &mut paint_cx);
2046    }
2047}