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::{display_map::TransformBlock, EditorStyle};
   7use clock::ReplicaId;
   8use collections::{BTreeMap, HashMap};
   9use gpui::{
  10    color::Color,
  11    elements::*,
  12    fonts::{HighlightStyle, Underline},
  13    geometry::{
  14        rect::RectF,
  15        vector::{vec2f, Vector2F},
  16        PathBuilder,
  17    },
  18    json::{self, ToJson},
  19    text_layout::{self, RunStyle, TextLayoutCache},
  20    AppContext, Axis, Border, Element, ElementBox, Event, EventContext, LayoutContext,
  21    MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext, WeakViewHandle,
  22};
  23use json::json;
  24use language::Bias;
  25use smallvec::SmallVec;
  26use std::{
  27    cmp::{self, Ordering},
  28    fmt::Write,
  29    ops::Range,
  30};
  31
  32pub struct EditorElement {
  33    view: WeakViewHandle<Editor>,
  34    style: EditorStyle,
  35}
  36
  37impl EditorElement {
  38    pub fn new(view: WeakViewHandle<Editor>, style: EditorStyle) -> Self {
  39        Self { view, style }
  40    }
  41
  42    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  43        self.view.upgrade(cx).unwrap().read(cx)
  44    }
  45
  46    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
  47    where
  48        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
  49    {
  50        self.view.upgrade(cx).unwrap().update(cx, f)
  51    }
  52
  53    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
  54        self.update_view(cx, |view, cx| view.snapshot(cx))
  55    }
  56
  57    fn mouse_down(
  58        &self,
  59        position: Vector2F,
  60        alt: bool,
  61        shift: bool,
  62        mut click_count: usize,
  63        layout: &mut LayoutState,
  64        paint: &mut PaintState,
  65        cx: &mut EventContext,
  66    ) -> bool {
  67        if paint.gutter_bounds.contains_point(position) {
  68            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
  69        } else if !paint.text_bounds.contains_point(position) {
  70            return false;
  71        }
  72
  73        let snapshot = self.snapshot(cx.app);
  74        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
  75
  76        if shift && alt {
  77            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
  78                position,
  79                overshoot,
  80            }));
  81        } else if shift {
  82            cx.dispatch_action(Select(SelectPhase::Extend {
  83                position,
  84                click_count,
  85            }));
  86        } else {
  87            cx.dispatch_action(Select(SelectPhase::Begin {
  88                position,
  89                add: alt,
  90                click_count,
  91            }));
  92        }
  93
  94        true
  95    }
  96
  97    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
  98        if self.view(cx.app.as_ref()).is_selecting() {
  99            cx.dispatch_action(Select(SelectPhase::End));
 100            true
 101        } else {
 102            false
 103        }
 104    }
 105
 106    fn mouse_dragged(
 107        &self,
 108        position: Vector2F,
 109        layout: &mut LayoutState,
 110        paint: &mut PaintState,
 111        cx: &mut EventContext,
 112    ) -> bool {
 113        let view = self.view(cx.app.as_ref());
 114
 115        if view.is_selecting() {
 116            let rect = paint.text_bounds;
 117            let mut scroll_delta = Vector2F::zero();
 118
 119            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 120            let top = rect.origin_y() + vertical_margin;
 121            let bottom = rect.lower_left().y() - vertical_margin;
 122            if position.y() < top {
 123                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 124            }
 125            if position.y() > bottom {
 126                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 127            }
 128
 129            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 130            let left = rect.origin_x() + horizontal_margin;
 131            let right = rect.upper_right().x() - horizontal_margin;
 132            if position.x() < left {
 133                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 134                    left - position.x(),
 135                ))
 136            }
 137            if position.x() > right {
 138                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 139                    position.x() - right,
 140                ))
 141            }
 142
 143            let snapshot = self.snapshot(cx.app);
 144            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 145
 146            cx.dispatch_action(Select(SelectPhase::Update {
 147                position,
 148                overshoot,
 149                scroll_position: (snapshot.scroll_position() + scroll_delta)
 150                    .clamp(Vector2F::zero(), layout.scroll_max),
 151            }));
 152            true
 153        } else {
 154            false
 155        }
 156    }
 157
 158    fn key_down(&self, input: Option<&str>, cx: &mut EventContext) -> bool {
 159        let view = self.view.upgrade(cx.app).unwrap();
 160
 161        if view.is_focused(cx.app) {
 162            if let Some(input) = input {
 163                cx.dispatch_action(Input(input.to_string()));
 164                true
 165            } else {
 166                false
 167            }
 168        } else {
 169            false
 170        }
 171    }
 172
 173    fn scroll(
 174        &self,
 175        position: Vector2F,
 176        mut delta: Vector2F,
 177        precise: bool,
 178        layout: &mut LayoutState,
 179        paint: &mut PaintState,
 180        cx: &mut EventContext,
 181    ) -> bool {
 182        if !paint.bounds.contains_point(position) {
 183            return false;
 184        }
 185
 186        let snapshot = self.snapshot(cx.app);
 187        let max_glyph_width = layout.em_width;
 188        if !precise {
 189            delta *= vec2f(max_glyph_width, layout.line_height);
 190        }
 191
 192        let scroll_position = snapshot.scroll_position();
 193        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 194        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 195        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 196
 197        cx.dispatch_action(Scroll(scroll_position));
 198
 199        true
 200    }
 201
 202    fn paint_background(
 203        &self,
 204        gutter_bounds: RectF,
 205        text_bounds: RectF,
 206        layout: &LayoutState,
 207        cx: &mut PaintContext,
 208    ) {
 209        let bounds = gutter_bounds.union_rect(text_bounds);
 210        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 211        let editor = self.view(cx.app);
 212        cx.scene.push_quad(Quad {
 213            bounds: gutter_bounds,
 214            background: Some(self.style.gutter_background),
 215            border: Border::new(0., Color::transparent_black()),
 216            corner_radius: 0.,
 217        });
 218        cx.scene.push_quad(Quad {
 219            bounds: text_bounds,
 220            background: Some(self.style.background),
 221            border: Border::new(0., Color::transparent_black()),
 222            corner_radius: 0.,
 223        });
 224
 225        if let EditorMode::Full = editor.mode {
 226            let mut active_rows = layout.active_rows.iter().peekable();
 227            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 228                let mut end_row = *start_row;
 229                while active_rows.peek().map_or(false, |r| {
 230                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 231                }) {
 232                    active_rows.next().unwrap();
 233                    end_row += 1;
 234                }
 235
 236                if !contains_non_empty_selection {
 237                    let origin = vec2f(
 238                        bounds.origin_x(),
 239                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 240                    );
 241                    let size = vec2f(
 242                        bounds.width(),
 243                        layout.line_height * (end_row - start_row + 1) as f32,
 244                    );
 245                    cx.scene.push_quad(Quad {
 246                        bounds: RectF::new(origin, size),
 247                        background: Some(self.style.active_line_background),
 248                        border: Border::default(),
 249                        corner_radius: 0.,
 250                    });
 251                }
 252            }
 253
 254            if let Some(highlighted_rows) = &layout.highlighted_rows {
 255                let origin = vec2f(
 256                    bounds.origin_x(),
 257                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 258                        - scroll_top,
 259                );
 260                let size = vec2f(
 261                    bounds.width(),
 262                    layout.line_height * highlighted_rows.len() as f32,
 263                );
 264                cx.scene.push_quad(Quad {
 265                    bounds: RectF::new(origin, size),
 266                    background: Some(self.style.highlighted_line_background),
 267                    border: Border::default(),
 268                    corner_radius: 0.,
 269                });
 270            }
 271        }
 272    }
 273
 274    fn paint_gutter(
 275        &mut self,
 276        bounds: RectF,
 277        visible_bounds: RectF,
 278        layout: &mut LayoutState,
 279        cx: &mut PaintContext,
 280    ) {
 281        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 282        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 283            if let Some(line) = line {
 284                let line_origin = bounds.origin()
 285                    + vec2f(
 286                        bounds.width() - line.width() - layout.gutter_padding,
 287                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 288                    );
 289                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 290            }
 291        }
 292
 293        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 294            let mut x = bounds.width() - layout.gutter_padding;
 295            let mut y = *row as f32 * layout.line_height - scroll_top;
 296            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 297            y += (layout.line_height - indicator.size().y()) / 2.;
 298            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 299        }
 300    }
 301
 302    fn paint_text(
 303        &mut self,
 304        bounds: RectF,
 305        visible_bounds: RectF,
 306        layout: &mut LayoutState,
 307        cx: &mut PaintContext,
 308    ) {
 309        let view = self.view(cx.app);
 310        let style = &self.style;
 311        let local_replica_id = view.replica_id(cx);
 312        let scroll_position = layout.snapshot.scroll_position();
 313        let start_row = scroll_position.y() as u32;
 314        let scroll_top = scroll_position.y() * layout.line_height;
 315        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 316        let max_glyph_width = layout.em_width;
 317        let scroll_left = scroll_position.x() * max_glyph_width;
 318        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 319
 320        cx.scene.push_layer(Some(bounds));
 321
 322        for (range, color) in &layout.highlighted_ranges {
 323            self.paint_highlighted_range(
 324                range.clone(),
 325                start_row,
 326                end_row,
 327                *color,
 328                0.,
 329                0.15 * layout.line_height,
 330                layout,
 331                content_origin,
 332                scroll_top,
 333                scroll_left,
 334                bounds,
 335                cx,
 336            );
 337        }
 338
 339        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 340        for (replica_id, selections) in &layout.selections {
 341            let style = style.replica_selection_style(*replica_id);
 342            let corner_radius = 0.15 * layout.line_height;
 343
 344            for selection in selections {
 345                self.paint_highlighted_range(
 346                    selection.start..selection.end,
 347                    start_row,
 348                    end_row,
 349                    style.selection,
 350                    corner_radius,
 351                    corner_radius * 2.,
 352                    layout,
 353                    content_origin,
 354                    scroll_top,
 355                    scroll_left,
 356                    bounds,
 357                    cx,
 358                );
 359
 360                if view.show_local_cursors() || *replica_id != local_replica_id {
 361                    let cursor_position = selection.head();
 362                    if (start_row..end_row).contains(&cursor_position.row()) {
 363                        let cursor_row_layout =
 364                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 365                        let x = cursor_row_layout.x_for_index(cursor_position.column() as usize)
 366                            - scroll_left;
 367                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 368                        cursors.push(Cursor {
 369                            color: style.cursor,
 370                            origin: content_origin + vec2f(x, y),
 371                            line_height: layout.line_height,
 372                        });
 373                    }
 374                }
 375            }
 376        }
 377
 378        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 379            // Draw glyphs
 380            for (ix, line) in layout.line_layouts.iter().enumerate() {
 381                let row = start_row + ix as u32;
 382                line.paint(
 383                    content_origin
 384                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 385                    visible_text_bounds,
 386                    layout.line_height,
 387                    cx,
 388                );
 389            }
 390        }
 391
 392        cx.scene.push_layer(Some(bounds));
 393        for cursor in cursors {
 394            cursor.paint(cx);
 395        }
 396        cx.scene.pop_layer();
 397
 398        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 399            cx.scene.push_stacking_context(None);
 400
 401            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 402            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 403            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 404            let mut list_origin = content_origin + vec2f(x, y);
 405            let list_height = context_menu.size().y();
 406
 407            if list_origin.y() + list_height > bounds.lower_left().y() {
 408                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 409            }
 410
 411            context_menu.paint(
 412                list_origin,
 413                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 414                cx,
 415            );
 416
 417            cx.scene.pop_stacking_context();
 418        }
 419
 420        cx.scene.pop_layer();
 421    }
 422
 423    fn paint_highlighted_range(
 424        &self,
 425        range: Range<DisplayPoint>,
 426        start_row: u32,
 427        end_row: u32,
 428        color: Color,
 429        corner_radius: f32,
 430        line_end_overshoot: f32,
 431        layout: &LayoutState,
 432        content_origin: Vector2F,
 433        scroll_top: f32,
 434        scroll_left: f32,
 435        bounds: RectF,
 436        cx: &mut PaintContext,
 437    ) {
 438        if range.start != range.end {
 439            let row_range = if range.end.column() == 0 {
 440                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 441            } else {
 442                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 443            };
 444
 445            let highlighted_range = HighlightedRange {
 446                color,
 447                line_height: layout.line_height,
 448                corner_radius,
 449                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 450                    - scroll_top,
 451                lines: row_range
 452                    .into_iter()
 453                    .map(|row| {
 454                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 455                        HighlightedRangeLine {
 456                            start_x: if row == range.start.row() {
 457                                content_origin.x()
 458                                    + line_layout.x_for_index(range.start.column() as usize)
 459                                    - scroll_left
 460                            } else {
 461                                content_origin.x() - scroll_left
 462                            },
 463                            end_x: if row == range.end.row() {
 464                                content_origin.x()
 465                                    + line_layout.x_for_index(range.end.column() as usize)
 466                                    - scroll_left
 467                            } else {
 468                                content_origin.x() + line_layout.width() + line_end_overshoot
 469                                    - scroll_left
 470                            },
 471                        }
 472                    })
 473                    .collect(),
 474            };
 475
 476            highlighted_range.paint(bounds, cx.scene);
 477        }
 478    }
 479
 480    fn paint_blocks(
 481        &mut self,
 482        bounds: RectF,
 483        visible_bounds: RectF,
 484        layout: &mut LayoutState,
 485        cx: &mut PaintContext,
 486    ) {
 487        let scroll_position = layout.snapshot.scroll_position();
 488        let scroll_left = scroll_position.x() * layout.em_width;
 489        let scroll_top = scroll_position.y() * layout.line_height;
 490
 491        for (row, element) in &mut layout.blocks {
 492            let origin = bounds.origin()
 493                + vec2f(-scroll_left, *row as f32 * layout.line_height - scroll_top);
 494            element.paint(origin, visible_bounds, cx);
 495        }
 496    }
 497
 498    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 499        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 500        let style = &self.style;
 501
 502        cx.text_layout_cache
 503            .layout_str(
 504                "1".repeat(digit_count).as_str(),
 505                style.text.font_size,
 506                &[(
 507                    digit_count,
 508                    RunStyle {
 509                        font_id: style.text.font_id,
 510                        color: Color::black(),
 511                        underline: None,
 512                    },
 513                )],
 514            )
 515            .width()
 516    }
 517
 518    fn layout_line_numbers(
 519        &self,
 520        rows: Range<u32>,
 521        active_rows: &BTreeMap<u32, bool>,
 522        snapshot: &EditorSnapshot,
 523        cx: &LayoutContext,
 524    ) -> Vec<Option<text_layout::Line>> {
 525        let style = &self.style;
 526        let include_line_numbers = snapshot.mode == EditorMode::Full;
 527        let mut line_number_layouts = Vec::with_capacity(rows.len());
 528        let mut line_number = String::new();
 529        for (ix, row) in snapshot
 530            .buffer_rows(rows.start)
 531            .take((rows.end - rows.start) as usize)
 532            .enumerate()
 533        {
 534            let display_row = rows.start + ix as u32;
 535            let color = if active_rows.contains_key(&display_row) {
 536                style.line_number_active
 537            } else {
 538                style.line_number
 539            };
 540            if let Some(buffer_row) = row {
 541                if include_line_numbers {
 542                    line_number.clear();
 543                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 544                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 545                        &line_number,
 546                        style.text.font_size,
 547                        &[(
 548                            line_number.len(),
 549                            RunStyle {
 550                                font_id: style.text.font_id,
 551                                color,
 552                                underline: None,
 553                            },
 554                        )],
 555                    )));
 556                }
 557            } else {
 558                line_number_layouts.push(None);
 559            }
 560        }
 561
 562        line_number_layouts
 563    }
 564
 565    fn layout_lines(
 566        &mut self,
 567        mut rows: Range<u32>,
 568        snapshot: &mut EditorSnapshot,
 569        cx: &LayoutContext,
 570    ) -> Vec<text_layout::Line> {
 571        rows.end = cmp::min(rows.end, snapshot.max_point().row() + 1);
 572        if rows.start >= rows.end {
 573            return Vec::new();
 574        }
 575
 576        // When the editor is empty and unfocused, then show the placeholder.
 577        if snapshot.is_empty() && !snapshot.is_focused() {
 578            let placeholder_style = self
 579                .style
 580                .placeholder_text
 581                .as_ref()
 582                .unwrap_or_else(|| &self.style.text);
 583            let placeholder_text = snapshot.placeholder_text();
 584            let placeholder_lines = placeholder_text
 585                .as_ref()
 586                .map_or("", AsRef::as_ref)
 587                .split('\n')
 588                .skip(rows.start as usize)
 589                .take(rows.len());
 590            return placeholder_lines
 591                .map(|line| {
 592                    cx.text_layout_cache.layout_str(
 593                        line,
 594                        placeholder_style.font_size,
 595                        &[(
 596                            line.len(),
 597                            RunStyle {
 598                                font_id: placeholder_style.font_id,
 599                                color: placeholder_style.color,
 600                                underline: None,
 601                            },
 602                        )],
 603                    )
 604                })
 605                .collect();
 606        } else {
 607            let style = &self.style;
 608            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 609                let mut highlight_style = HighlightStyle {
 610                    color: style.text.color,
 611                    font_properties: style.text.font_properties,
 612                    ..Default::default()
 613                };
 614
 615                if let Some(syntax_highlight_style) = chunk
 616                    .syntax_highlight_id
 617                    .and_then(|id| id.style(&style.syntax))
 618                {
 619                    highlight_style.highlight(syntax_highlight_style);
 620                }
 621
 622                if let Some(style) = chunk.highlight_style {
 623                    highlight_style.highlight(style);
 624                }
 625
 626                if let Some(severity) = chunk.diagnostic {
 627                    let diagnostic_style = super::diagnostic_style(severity, true, style);
 628                    highlight_style.underline = Some(Underline {
 629                        color: diagnostic_style.message.text.color,
 630                        thickness: 1.0.into(),
 631                        squiggly: true,
 632                    });
 633                }
 634
 635                (chunk.text, highlight_style)
 636            });
 637            layout_highlighted_chunks(
 638                chunks,
 639                &style.text,
 640                &cx.text_layout_cache,
 641                &cx.font_cache,
 642                MAX_LINE_LEN,
 643                rows.len() as usize,
 644            )
 645        }
 646    }
 647
 648    fn layout_blocks(
 649        &mut self,
 650        rows: Range<u32>,
 651        snapshot: &EditorSnapshot,
 652        width: f32,
 653        gutter_padding: f32,
 654        gutter_width: f32,
 655        em_width: f32,
 656        text_x: f32,
 657        line_height: f32,
 658        style: &EditorStyle,
 659        line_layouts: &[text_layout::Line],
 660        cx: &mut LayoutContext,
 661    ) -> Vec<(u32, ElementBox)> {
 662        let scroll_x = snapshot.scroll_position.x();
 663        snapshot
 664            .blocks_in_range(rows.clone())
 665            .map(|(block_row, block)| {
 666                let mut element = match block {
 667                    TransformBlock::Custom(block) => {
 668                        let align_to = block
 669                            .position()
 670                            .to_point(&snapshot.buffer_snapshot)
 671                            .to_display_point(snapshot);
 672                        let anchor_x = text_x
 673                            + if rows.contains(&align_to.row()) {
 674                                line_layouts[(align_to.row() - rows.start) as usize]
 675                                    .x_for_index(align_to.column() as usize)
 676                            } else {
 677                                layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 678                                    .x_for_index(align_to.column() as usize)
 679                            };
 680
 681                        block.render(&BlockContext {
 682                            cx,
 683                            anchor_x,
 684                            gutter_padding,
 685                            line_height,
 686                            scroll_x,
 687                            gutter_width,
 688                            em_width,
 689                        })
 690                    }
 691                    TransformBlock::ExcerptHeader {
 692                        buffer,
 693                        starts_new_buffer,
 694                        ..
 695                    } => {
 696                        if *starts_new_buffer {
 697                            let style = &self.style.diagnostic_path_header;
 698                            let font_size =
 699                                (style.text_scale_factor * self.style.text.font_size).round();
 700
 701                            let mut filename = None;
 702                            let mut parent_path = None;
 703                            if let Some(path) = buffer.path() {
 704                                filename =
 705                                    path.file_name().map(|f| f.to_string_lossy().to_string());
 706                                parent_path =
 707                                    path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 708                            }
 709
 710                            Flex::row()
 711                                .with_child(
 712                                    Label::new(
 713                                        filename.unwrap_or_else(|| "untitled".to_string()),
 714                                        style.filename.text.clone().with_font_size(font_size),
 715                                    )
 716                                    .contained()
 717                                    .with_style(style.filename.container)
 718                                    .boxed(),
 719                                )
 720                                .with_children(parent_path.map(|path| {
 721                                    Label::new(
 722                                        path,
 723                                        style.path.text.clone().with_font_size(font_size),
 724                                    )
 725                                    .contained()
 726                                    .with_style(style.path.container)
 727                                    .boxed()
 728                                }))
 729                                .aligned()
 730                                .left()
 731                                .contained()
 732                                .with_style(style.container)
 733                                .with_padding_left(gutter_padding + scroll_x * em_width)
 734                                .expanded()
 735                                .named("path header block")
 736                        } else {
 737                            let text_style = self.style.text.clone();
 738                            Label::new("".to_string(), text_style)
 739                                .contained()
 740                                .with_padding_left(gutter_padding + scroll_x * em_width)
 741                                .named("collapsed context")
 742                        }
 743                    }
 744                };
 745
 746                element.layout(
 747                    SizeConstraint {
 748                        min: Vector2F::zero(),
 749                        max: vec2f(width, block.height() as f32 * line_height),
 750                    },
 751                    cx,
 752                );
 753                (block_row, element)
 754            })
 755            .collect()
 756    }
 757}
 758
 759impl Element for EditorElement {
 760    type LayoutState = LayoutState;
 761    type PaintState = PaintState;
 762
 763    fn layout(
 764        &mut self,
 765        constraint: SizeConstraint,
 766        cx: &mut LayoutContext,
 767    ) -> (Vector2F, Self::LayoutState) {
 768        let mut size = constraint.max;
 769        if size.x().is_infinite() {
 770            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
 771        }
 772
 773        let snapshot = self.snapshot(cx.app);
 774        let style = self.style.clone();
 775        let line_height = style.text.line_height(cx.font_cache);
 776
 777        let gutter_padding;
 778        let gutter_width;
 779        let gutter_margin;
 780        if snapshot.mode == EditorMode::Full {
 781            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
 782            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
 783            gutter_margin = -style.text.descent(cx.font_cache);
 784        } else {
 785            gutter_padding = 0.0;
 786            gutter_width = 0.0;
 787            gutter_margin = 0.0;
 788        };
 789
 790        let text_width = size.x() - gutter_width;
 791        let em_width = style.text.em_width(cx.font_cache);
 792        let em_advance = style.text.em_advance(cx.font_cache);
 793        let overscroll = vec2f(em_width, 0.);
 794        let snapshot = self.update_view(cx.app, |view, cx| {
 795            let wrap_width = match view.soft_wrap_mode(cx) {
 796                SoftWrap::None => None,
 797                SoftWrap::EditorWidth => {
 798                    Some(text_width - gutter_margin - overscroll.x() - em_width)
 799                }
 800                SoftWrap::Column(column) => Some(column as f32 * em_advance),
 801            };
 802
 803            if view.set_wrap_width(wrap_width, cx) {
 804                view.snapshot(cx)
 805            } else {
 806                snapshot
 807            }
 808        });
 809
 810        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
 811        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
 812            size.set_y(
 813                scroll_height
 814                    .min(constraint.max_along(Axis::Vertical))
 815                    .max(constraint.min_along(Axis::Vertical))
 816                    .min(line_height * max_lines as f32),
 817            )
 818        } else if size.y().is_infinite() {
 819            size.set_y(scroll_height);
 820        }
 821        let gutter_size = vec2f(gutter_width, size.y());
 822        let text_size = vec2f(text_width, size.y());
 823
 824        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
 825            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
 826            let snapshot = view.snapshot(cx);
 827            (autoscroll_horizontally, snapshot)
 828        });
 829
 830        let scroll_position = snapshot.scroll_position();
 831        let start_row = scroll_position.y() as u32;
 832        let scroll_top = scroll_position.y() * line_height;
 833        let end_row = ((scroll_top + size.y()) / line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 834
 835        let start_anchor = if start_row == 0 {
 836            Anchor::min()
 837        } else {
 838            snapshot
 839                .buffer_snapshot
 840                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
 841        };
 842        let end_anchor = if end_row > snapshot.max_point().row() {
 843            Anchor::max()
 844        } else {
 845            snapshot
 846                .buffer_snapshot
 847                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
 848        };
 849
 850        let mut selections = HashMap::default();
 851        let mut active_rows = BTreeMap::new();
 852        let mut highlighted_rows = None;
 853        let mut highlighted_ranges = Vec::new();
 854        self.update_view(cx.app, |view, cx| {
 855            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
 856
 857            highlighted_rows = view.highlighted_rows();
 858            highlighted_ranges = view.background_highlights_in_range(
 859                start_anchor.clone()..end_anchor.clone(),
 860                &display_map,
 861            );
 862
 863            let local_selections = view
 864                .local_selections_in_range(start_anchor.clone()..end_anchor.clone(), &display_map);
 865            for selection in &local_selections {
 866                let is_empty = selection.start == selection.end;
 867                let selection_start = snapshot.prev_line_boundary(selection.start).1;
 868                let selection_end = snapshot.next_line_boundary(selection.end).1;
 869                for row in cmp::max(selection_start.row(), start_row)
 870                    ..=cmp::min(selection_end.row(), end_row)
 871                {
 872                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
 873                    *contains_non_empty_selection |= !is_empty;
 874                }
 875            }
 876            selections.insert(
 877                view.replica_id(cx),
 878                local_selections
 879                    .into_iter()
 880                    .map(|selection| crate::Selection {
 881                        id: selection.id,
 882                        goal: selection.goal,
 883                        reversed: selection.reversed,
 884                        start: selection.start.to_display_point(&display_map),
 885                        end: selection.end.to_display_point(&display_map),
 886                    })
 887                    .collect(),
 888            );
 889
 890            for (replica_id, selection) in display_map
 891                .buffer_snapshot
 892                .remote_selections_in_range(&(start_anchor..end_anchor))
 893            {
 894                selections
 895                    .entry(replica_id)
 896                    .or_insert(Vec::new())
 897                    .push(crate::Selection {
 898                        id: selection.id,
 899                        goal: selection.goal,
 900                        reversed: selection.reversed,
 901                        start: selection.start.to_display_point(&display_map),
 902                        end: selection.end.to_display_point(&display_map),
 903                    });
 904            }
 905        });
 906
 907        let line_number_layouts =
 908            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
 909
 910        let mut max_visible_line_width = 0.0;
 911        let line_layouts = self.layout_lines(start_row..end_row, &mut snapshot, cx);
 912        for line in &line_layouts {
 913            if line.width() > max_visible_line_width {
 914                max_visible_line_width = line.width();
 915            }
 916        }
 917
 918        let style = self.style.clone();
 919        let longest_line_width = layout_line(
 920            snapshot.longest_row(),
 921            &snapshot,
 922            &style,
 923            cx.text_layout_cache,
 924        )
 925        .width();
 926        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
 927        let em_width = style.text.em_width(cx.font_cache);
 928        let max_row = snapshot.max_point().row();
 929        let scroll_max = vec2f(
 930            ((scroll_width - text_size.x()) / em_width).max(0.0),
 931            max_row.saturating_sub(1) as f32,
 932        );
 933
 934        let mut context_menu = None;
 935        let mut code_actions_indicator = None;
 936        self.update_view(cx.app, |view, cx| {
 937            let clamped = view.clamp_scroll_left(scroll_max.x());
 938            let autoscrolled;
 939            if autoscroll_horizontally {
 940                autoscrolled = view.autoscroll_horizontally(
 941                    start_row,
 942                    text_size.x(),
 943                    scroll_width,
 944                    em_width,
 945                    &line_layouts,
 946                    cx,
 947                );
 948            } else {
 949                autoscrolled = false;
 950            }
 951
 952            if clamped || autoscrolled {
 953                snapshot = view.snapshot(cx);
 954            }
 955
 956            let newest_selection_head = view
 957                .newest_selection_with_snapshot::<usize>(&snapshot.buffer_snapshot)
 958                .head()
 959                .to_display_point(&snapshot);
 960
 961            if (start_row..end_row).contains(&newest_selection_head.row()) {
 962                let style = view.style(cx);
 963                if view.context_menu_visible() {
 964                    context_menu =
 965                        view.render_context_menu(newest_selection_head, style.clone(), cx);
 966                }
 967
 968                code_actions_indicator = view
 969                    .render_code_actions_indicator(&style, cx)
 970                    .map(|indicator| (newest_selection_head.row(), indicator));
 971            }
 972        });
 973
 974        if let Some((_, context_menu)) = context_menu.as_mut() {
 975            context_menu.layout(
 976                SizeConstraint {
 977                    min: Vector2F::zero(),
 978                    max: vec2f(
 979                        f32::INFINITY,
 980                        (12. * line_height).min((size.y() - line_height) / 2.),
 981                    ),
 982                },
 983                cx,
 984            );
 985        }
 986
 987        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
 988            indicator.layout(
 989                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
 990                cx,
 991            );
 992        }
 993
 994        let blocks = self.layout_blocks(
 995            start_row..end_row,
 996            &snapshot,
 997            size.x().max(scroll_width + gutter_width),
 998            gutter_padding,
 999            gutter_width,
1000            em_width,
1001            gutter_width + gutter_margin,
1002            line_height,
1003            &style,
1004            &line_layouts,
1005            cx,
1006        );
1007
1008        (
1009            size,
1010            LayoutState {
1011                size,
1012                scroll_max,
1013                gutter_size,
1014                gutter_padding,
1015                text_size,
1016                gutter_margin,
1017                snapshot,
1018                active_rows,
1019                highlighted_rows,
1020                highlighted_ranges,
1021                line_layouts,
1022                line_number_layouts,
1023                blocks,
1024                line_height,
1025                em_width,
1026                em_advance,
1027                selections,
1028                context_menu,
1029                code_actions_indicator,
1030            },
1031        )
1032    }
1033
1034    fn paint(
1035        &mut self,
1036        bounds: RectF,
1037        visible_bounds: RectF,
1038        layout: &mut Self::LayoutState,
1039        cx: &mut PaintContext,
1040    ) -> Self::PaintState {
1041        cx.scene.push_layer(Some(bounds));
1042
1043        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1044        let text_bounds = RectF::new(
1045            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1046            layout.text_size,
1047        );
1048
1049        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1050        if layout.gutter_size.x() > 0. {
1051            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1052        }
1053        self.paint_text(text_bounds, visible_bounds, layout, cx);
1054
1055        if !layout.blocks.is_empty() {
1056            cx.scene.push_layer(Some(bounds));
1057            self.paint_blocks(bounds, visible_bounds, layout, cx);
1058            cx.scene.pop_layer();
1059        }
1060
1061        cx.scene.pop_layer();
1062
1063        PaintState {
1064            bounds,
1065            gutter_bounds,
1066            text_bounds,
1067        }
1068    }
1069
1070    fn dispatch_event(
1071        &mut self,
1072        event: &Event,
1073        _: RectF,
1074        layout: &mut LayoutState,
1075        paint: &mut PaintState,
1076        cx: &mut EventContext,
1077    ) -> bool {
1078        if let Some((_, context_menu)) = &mut layout.context_menu {
1079            if context_menu.dispatch_event(event, cx) {
1080                return true;
1081            }
1082        }
1083
1084        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1085            if indicator.dispatch_event(event, cx) {
1086                return true;
1087            }
1088        }
1089
1090        for (_, block) in &mut layout.blocks {
1091            if block.dispatch_event(event, cx) {
1092                return true;
1093            }
1094        }
1095
1096        match event {
1097            Event::LeftMouseDown {
1098                position,
1099                alt,
1100                shift,
1101                click_count,
1102                ..
1103            } => self.mouse_down(*position, *alt, *shift, *click_count, layout, paint, cx),
1104            Event::LeftMouseUp { position } => self.mouse_up(*position, cx),
1105            Event::LeftMouseDragged { position } => {
1106                self.mouse_dragged(*position, layout, paint, cx)
1107            }
1108            Event::ScrollWheel {
1109                position,
1110                delta,
1111                precise,
1112            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1113            Event::KeyDown { input, .. } => self.key_down(input.as_deref(), cx),
1114            _ => false,
1115        }
1116    }
1117
1118    fn debug(
1119        &self,
1120        bounds: RectF,
1121        _: &Self::LayoutState,
1122        _: &Self::PaintState,
1123        _: &gpui::DebugContext,
1124    ) -> json::Value {
1125        json!({
1126            "type": "BufferElement",
1127            "bounds": bounds.to_json()
1128        })
1129    }
1130}
1131
1132pub struct LayoutState {
1133    size: Vector2F,
1134    scroll_max: Vector2F,
1135    gutter_size: Vector2F,
1136    gutter_padding: f32,
1137    gutter_margin: f32,
1138    text_size: Vector2F,
1139    snapshot: EditorSnapshot,
1140    active_rows: BTreeMap<u32, bool>,
1141    highlighted_rows: Option<Range<u32>>,
1142    line_layouts: Vec<text_layout::Line>,
1143    line_number_layouts: Vec<Option<text_layout::Line>>,
1144    blocks: Vec<(u32, ElementBox)>,
1145    line_height: f32,
1146    em_width: f32,
1147    em_advance: f32,
1148    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1149    selections: HashMap<ReplicaId, Vec<text::Selection<DisplayPoint>>>,
1150    context_menu: Option<(DisplayPoint, ElementBox)>,
1151    code_actions_indicator: Option<(u32, ElementBox)>,
1152}
1153
1154fn layout_line(
1155    row: u32,
1156    snapshot: &EditorSnapshot,
1157    style: &EditorStyle,
1158    layout_cache: &TextLayoutCache,
1159) -> text_layout::Line {
1160    let mut line = snapshot.line(row);
1161
1162    if line.len() > MAX_LINE_LEN {
1163        let mut len = MAX_LINE_LEN;
1164        while !line.is_char_boundary(len) {
1165            len -= 1;
1166        }
1167        line.truncate(len);
1168    }
1169
1170    layout_cache.layout_str(
1171        &line,
1172        style.text.font_size,
1173        &[(
1174            snapshot.line_len(row) as usize,
1175            RunStyle {
1176                font_id: style.text.font_id,
1177                color: Color::black(),
1178                underline: None,
1179            },
1180        )],
1181    )
1182}
1183
1184pub struct PaintState {
1185    bounds: RectF,
1186    gutter_bounds: RectF,
1187    text_bounds: RectF,
1188}
1189
1190impl PaintState {
1191    fn point_for_position(
1192        &self,
1193        snapshot: &EditorSnapshot,
1194        layout: &LayoutState,
1195        position: Vector2F,
1196    ) -> (DisplayPoint, u32) {
1197        let scroll_position = snapshot.scroll_position();
1198        let position = position - self.text_bounds.origin();
1199        let y = position.y().max(0.0).min(layout.size.y());
1200        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1201        let row = cmp::min(row, snapshot.max_point().row());
1202        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1203        let x = position.x() + (scroll_position.x() * layout.em_width);
1204
1205        let column = if x >= 0.0 {
1206            line.index_for_x(x)
1207                .map(|ix| ix as u32)
1208                .unwrap_or_else(|| snapshot.line_len(row))
1209        } else {
1210            0
1211        };
1212        let overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1213
1214        (DisplayPoint::new(row, column), overshoot)
1215    }
1216}
1217
1218struct Cursor {
1219    origin: Vector2F,
1220    line_height: f32,
1221    color: Color,
1222}
1223
1224impl Cursor {
1225    fn paint(&self, cx: &mut PaintContext) {
1226        cx.scene.push_quad(Quad {
1227            bounds: RectF::new(self.origin, vec2f(2.0, self.line_height)),
1228            background: Some(self.color),
1229            border: Border::new(0., Color::black()),
1230            corner_radius: 0.,
1231        });
1232    }
1233}
1234
1235#[derive(Debug)]
1236struct HighlightedRange {
1237    start_y: f32,
1238    line_height: f32,
1239    lines: Vec<HighlightedRangeLine>,
1240    color: Color,
1241    corner_radius: f32,
1242}
1243
1244#[derive(Debug)]
1245struct HighlightedRangeLine {
1246    start_x: f32,
1247    end_x: f32,
1248}
1249
1250impl HighlightedRange {
1251    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1252        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1253            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1254            self.paint_lines(
1255                self.start_y + self.line_height,
1256                &self.lines[1..],
1257                bounds,
1258                scene,
1259            );
1260        } else {
1261            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1262        }
1263    }
1264
1265    fn paint_lines(
1266        &self,
1267        start_y: f32,
1268        lines: &[HighlightedRangeLine],
1269        bounds: RectF,
1270        scene: &mut Scene,
1271    ) {
1272        if lines.is_empty() {
1273            return;
1274        }
1275
1276        let mut path = PathBuilder::new();
1277        let first_line = lines.first().unwrap();
1278        let last_line = lines.last().unwrap();
1279
1280        let first_top_left = vec2f(first_line.start_x, start_y);
1281        let first_top_right = vec2f(first_line.end_x, start_y);
1282
1283        let curve_height = vec2f(0., self.corner_radius);
1284        let curve_width = |start_x: f32, end_x: f32| {
1285            let max = (end_x - start_x) / 2.;
1286            let width = if max < self.corner_radius {
1287                max
1288            } else {
1289                self.corner_radius
1290            };
1291
1292            vec2f(width, 0.)
1293        };
1294
1295        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1296        path.reset(first_top_right - top_curve_width);
1297        path.curve_to(first_top_right + curve_height, first_top_right);
1298
1299        let mut iter = lines.iter().enumerate().peekable();
1300        while let Some((ix, line)) = iter.next() {
1301            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1302
1303            if let Some((_, next_line)) = iter.peek() {
1304                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1305
1306                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1307                    Ordering::Equal => {
1308                        path.line_to(bottom_right);
1309                    }
1310                    Ordering::Less => {
1311                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1312                        path.line_to(bottom_right - curve_height);
1313                        if self.corner_radius > 0. {
1314                            path.curve_to(bottom_right - curve_width, bottom_right);
1315                        }
1316                        path.line_to(next_top_right + curve_width);
1317                        if self.corner_radius > 0. {
1318                            path.curve_to(next_top_right + curve_height, next_top_right);
1319                        }
1320                    }
1321                    Ordering::Greater => {
1322                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1323                        path.line_to(bottom_right - curve_height);
1324                        if self.corner_radius > 0. {
1325                            path.curve_to(bottom_right + curve_width, bottom_right);
1326                        }
1327                        path.line_to(next_top_right - curve_width);
1328                        if self.corner_radius > 0. {
1329                            path.curve_to(next_top_right + curve_height, next_top_right);
1330                        }
1331                    }
1332                }
1333            } else {
1334                let curve_width = curve_width(line.start_x, line.end_x);
1335                path.line_to(bottom_right - curve_height);
1336                if self.corner_radius > 0. {
1337                    path.curve_to(bottom_right - curve_width, bottom_right);
1338                }
1339
1340                let bottom_left = vec2f(line.start_x, bottom_right.y());
1341                path.line_to(bottom_left + curve_width);
1342                if self.corner_radius > 0. {
1343                    path.curve_to(bottom_left - curve_height, bottom_left);
1344                }
1345            }
1346        }
1347
1348        if first_line.start_x > last_line.start_x {
1349            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1350            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1351            path.line_to(second_top_left + curve_height);
1352            if self.corner_radius > 0. {
1353                path.curve_to(second_top_left + curve_width, second_top_left);
1354            }
1355            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1356            path.line_to(first_bottom_left - curve_width);
1357            if self.corner_radius > 0. {
1358                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1359            }
1360        }
1361
1362        path.line_to(first_top_left + curve_height);
1363        if self.corner_radius > 0. {
1364            path.curve_to(first_top_left + top_curve_width, first_top_left);
1365        }
1366        path.line_to(first_top_right - top_curve_width);
1367
1368        scene.push_path(path.build(self.color, Some(bounds)));
1369    }
1370}
1371
1372fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1373    delta.powf(1.5) / 100.0
1374}
1375
1376fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1377    delta.powf(1.2) / 300.0
1378}
1379
1380#[cfg(test)]
1381mod tests {
1382    use super::*;
1383    use crate::{Editor, MultiBuffer};
1384    use postage::watch;
1385    use util::test::sample_text;
1386    use workspace::Settings;
1387
1388    #[gpui::test]
1389    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1390        let settings = watch::channel_with(Settings::test(cx));
1391        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1392        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1393            Editor::new(EditorMode::Full, buffer, None, settings.1, None, cx)
1394        });
1395        let element = EditorElement::new(editor.downgrade(), editor.read(cx).style(cx));
1396
1397        let layouts = editor.update(cx, |editor, cx| {
1398            let snapshot = editor.snapshot(cx);
1399            let mut presenter = cx.build_presenter(window_id, 30.);
1400            let mut layout_cx = presenter.build_layout_context(false, cx);
1401            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1402        });
1403        assert_eq!(layouts.len(), 6);
1404    }
1405}