element.rs

   1use super::{
   2    display_map::{BlockContext, ToDisplayPoint},
   3    Anchor, DisplayPoint, Editor, EditorMode, EditorSettings, EditorSnapshot, EditorStyle, Input,
   4    Scroll, Select, SelectPhase, SoftWrap, ToPoint, MAX_LINE_LEN,
   5};
   6use crate::display_map::TransformBlock;
   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    keymap::Keystroke,
  20    text_layout::{self, RunStyle, TextLayoutCache},
  21    AppContext, Axis, Border, Element, ElementBox, Event, EventContext, LayoutContext,
  22    MutableAppContext, PaintContext, Quad, Scene, SizeConstraint, ViewContext, WeakViewHandle,
  23};
  24use json::json;
  25use language::Bias;
  26use smallvec::SmallVec;
  27use std::{
  28    cmp::{self, Ordering},
  29    fmt::Write,
  30    ops::Range,
  31};
  32
  33pub struct EditorElement {
  34    view: WeakViewHandle<Editor>,
  35    settings: EditorSettings,
  36}
  37
  38impl EditorElement {
  39    pub fn new(view: WeakViewHandle<Editor>, settings: EditorSettings) -> Self {
  40        Self { view, settings }
  41    }
  42
  43    fn view<'a>(&self, cx: &'a AppContext) -> &'a Editor {
  44        self.view.upgrade(cx).unwrap().read(cx)
  45    }
  46
  47    fn update_view<F, T>(&self, cx: &mut MutableAppContext, f: F) -> T
  48    where
  49        F: FnOnce(&mut Editor, &mut ViewContext<Editor>) -> T,
  50    {
  51        self.view.upgrade(cx).unwrap().update(cx, f)
  52    }
  53
  54    fn snapshot(&self, cx: &mut MutableAppContext) -> EditorSnapshot {
  55        self.update_view(cx, |view, cx| view.snapshot(cx))
  56    }
  57
  58    fn mouse_down(
  59        &self,
  60        position: Vector2F,
  61        alt: bool,
  62        shift: bool,
  63        mut click_count: usize,
  64        layout: &mut LayoutState,
  65        paint: &mut PaintState,
  66        cx: &mut EventContext,
  67    ) -> bool {
  68        if paint.gutter_bounds.contains_point(position) {
  69            click_count = 3; // Simulate triple-click when clicking the gutter to select lines
  70        } else if !paint.text_bounds.contains_point(position) {
  71            return false;
  72        }
  73
  74        let snapshot = self.snapshot(cx.app);
  75        let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
  76
  77        if shift && alt {
  78            cx.dispatch_action(Select(SelectPhase::BeginColumnar {
  79                position,
  80                overshoot,
  81            }));
  82        } else if shift {
  83            cx.dispatch_action(Select(SelectPhase::Extend {
  84                position,
  85                click_count,
  86            }));
  87        } else {
  88            cx.dispatch_action(Select(SelectPhase::Begin {
  89                position,
  90                add: alt,
  91                click_count,
  92            }));
  93        }
  94
  95        true
  96    }
  97
  98    fn mouse_up(&self, _position: Vector2F, cx: &mut EventContext) -> bool {
  99        if self.view(cx.app.as_ref()).is_selecting() {
 100            cx.dispatch_action(Select(SelectPhase::End));
 101            true
 102        } else {
 103            false
 104        }
 105    }
 106
 107    fn mouse_dragged(
 108        &self,
 109        position: Vector2F,
 110        layout: &mut LayoutState,
 111        paint: &mut PaintState,
 112        cx: &mut EventContext,
 113    ) -> bool {
 114        let view = self.view(cx.app.as_ref());
 115
 116        if view.is_selecting() {
 117            let rect = paint.text_bounds;
 118            let mut scroll_delta = Vector2F::zero();
 119
 120            let vertical_margin = layout.line_height.min(rect.height() / 3.0);
 121            let top = rect.origin_y() + vertical_margin;
 122            let bottom = rect.lower_left().y() - vertical_margin;
 123            if position.y() < top {
 124                scroll_delta.set_y(-scale_vertical_mouse_autoscroll_delta(top - position.y()))
 125            }
 126            if position.y() > bottom {
 127                scroll_delta.set_y(scale_vertical_mouse_autoscroll_delta(position.y() - bottom))
 128            }
 129
 130            let horizontal_margin = layout.line_height.min(rect.width() / 3.0);
 131            let left = rect.origin_x() + horizontal_margin;
 132            let right = rect.upper_right().x() - horizontal_margin;
 133            if position.x() < left {
 134                scroll_delta.set_x(-scale_horizontal_mouse_autoscroll_delta(
 135                    left - position.x(),
 136                ))
 137            }
 138            if position.x() > right {
 139                scroll_delta.set_x(scale_horizontal_mouse_autoscroll_delta(
 140                    position.x() - right,
 141                ))
 142            }
 143
 144            let snapshot = self.snapshot(cx.app);
 145            let (position, overshoot) = paint.point_for_position(&snapshot, layout, position);
 146
 147            cx.dispatch_action(Select(SelectPhase::Update {
 148                position,
 149                overshoot,
 150                scroll_position: (snapshot.scroll_position() + scroll_delta)
 151                    .clamp(Vector2F::zero(), layout.scroll_max),
 152            }));
 153            true
 154        } else {
 155            false
 156        }
 157    }
 158
 159    fn key_down(&self, chars: &str, keystroke: &Keystroke, cx: &mut EventContext) -> bool {
 160        let view = self.view.upgrade(cx.app).unwrap();
 161
 162        if view.is_focused(cx.app) {
 163            if chars.is_empty() {
 164                false
 165            } else {
 166                if chars.chars().any(|c| c.is_control()) || keystroke.cmd || keystroke.ctrl {
 167                    false
 168                } else {
 169                    cx.dispatch_action(Input(chars.to_string()));
 170                    true
 171                }
 172            }
 173        } else {
 174            false
 175        }
 176    }
 177
 178    fn scroll(
 179        &self,
 180        position: Vector2F,
 181        mut delta: Vector2F,
 182        precise: bool,
 183        layout: &mut LayoutState,
 184        paint: &mut PaintState,
 185        cx: &mut EventContext,
 186    ) -> bool {
 187        if !paint.bounds.contains_point(position) {
 188            return false;
 189        }
 190
 191        let snapshot = self.snapshot(cx.app);
 192        let max_glyph_width = layout.em_width;
 193        if !precise {
 194            delta *= vec2f(max_glyph_width, layout.line_height);
 195        }
 196
 197        let scroll_position = snapshot.scroll_position();
 198        let x = (scroll_position.x() * max_glyph_width - delta.x()) / max_glyph_width;
 199        let y = (scroll_position.y() * layout.line_height - delta.y()) / layout.line_height;
 200        let scroll_position = vec2f(x, y).clamp(Vector2F::zero(), layout.scroll_max);
 201
 202        cx.dispatch_action(Scroll(scroll_position));
 203
 204        true
 205    }
 206
 207    fn paint_background(
 208        &self,
 209        gutter_bounds: RectF,
 210        text_bounds: RectF,
 211        layout: &LayoutState,
 212        cx: &mut PaintContext,
 213    ) {
 214        let bounds = gutter_bounds.union_rect(text_bounds);
 215        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 216        let editor = self.view(cx.app);
 217        let style = &self.settings.style;
 218        cx.scene.push_quad(Quad {
 219            bounds: gutter_bounds,
 220            background: Some(style.gutter_background),
 221            border: Border::new(0., Color::transparent_black()),
 222            corner_radius: 0.,
 223        });
 224        cx.scene.push_quad(Quad {
 225            bounds: text_bounds,
 226            background: Some(style.background),
 227            border: Border::new(0., Color::transparent_black()),
 228            corner_radius: 0.,
 229        });
 230
 231        if let EditorMode::Full = editor.mode {
 232            let mut active_rows = layout.active_rows.iter().peekable();
 233            while let Some((start_row, contains_non_empty_selection)) = active_rows.next() {
 234                let mut end_row = *start_row;
 235                while active_rows.peek().map_or(false, |r| {
 236                    *r.0 == end_row + 1 && r.1 == contains_non_empty_selection
 237                }) {
 238                    active_rows.next().unwrap();
 239                    end_row += 1;
 240                }
 241
 242                if !contains_non_empty_selection {
 243                    let origin = vec2f(
 244                        bounds.origin_x(),
 245                        bounds.origin_y() + (layout.line_height * *start_row as f32) - scroll_top,
 246                    );
 247                    let size = vec2f(
 248                        bounds.width(),
 249                        layout.line_height * (end_row - start_row + 1) as f32,
 250                    );
 251                    cx.scene.push_quad(Quad {
 252                        bounds: RectF::new(origin, size),
 253                        background: Some(style.active_line_background),
 254                        border: Border::default(),
 255                        corner_radius: 0.,
 256                    });
 257                }
 258            }
 259
 260            if let Some(highlighted_rows) = &layout.highlighted_rows {
 261                let origin = vec2f(
 262                    bounds.origin_x(),
 263                    bounds.origin_y() + (layout.line_height * highlighted_rows.start as f32)
 264                        - scroll_top,
 265                );
 266                let size = vec2f(
 267                    bounds.width(),
 268                    layout.line_height * highlighted_rows.len() as f32,
 269                );
 270                cx.scene.push_quad(Quad {
 271                    bounds: RectF::new(origin, size),
 272                    background: Some(style.highlighted_line_background),
 273                    border: Border::default(),
 274                    corner_radius: 0.,
 275                });
 276            }
 277        }
 278    }
 279
 280    fn paint_gutter(
 281        &mut self,
 282        bounds: RectF,
 283        visible_bounds: RectF,
 284        layout: &LayoutState,
 285        cx: &mut PaintContext,
 286    ) {
 287        let scroll_top = layout.snapshot.scroll_position().y() * layout.line_height;
 288        for (ix, line) in layout.line_number_layouts.iter().enumerate() {
 289            if let Some(line) = line {
 290                let line_origin = bounds.origin()
 291                    + vec2f(
 292                        bounds.width() - line.width() - layout.gutter_padding,
 293                        ix as f32 * layout.line_height - (scroll_top % layout.line_height),
 294                    );
 295                line.paint(line_origin, visible_bounds, layout.line_height, cx);
 296            }
 297        }
 298    }
 299
 300    fn paint_text(
 301        &mut self,
 302        bounds: RectF,
 303        visible_bounds: RectF,
 304        layout: &mut LayoutState,
 305        cx: &mut PaintContext,
 306    ) {
 307        let view = self.view(cx.app);
 308        let style = &self.settings.style;
 309        let local_replica_id = view.replica_id(cx);
 310        let scroll_position = layout.snapshot.scroll_position();
 311        let start_row = scroll_position.y() as u32;
 312        let scroll_top = scroll_position.y() * layout.line_height;
 313        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 314        let max_glyph_width = layout.em_width;
 315        let scroll_left = scroll_position.x() * max_glyph_width;
 316        let content_origin = bounds.origin() + layout.text_offset;
 317
 318        cx.scene.push_layer(Some(bounds));
 319
 320        for (range, color) in &layout.highlighted_ranges {
 321            self.paint_highlighted_range(
 322                range.clone(),
 323                start_row,
 324                end_row,
 325                *color,
 326                0.,
 327                0.15 * layout.line_height,
 328                layout,
 329                content_origin,
 330                scroll_top,
 331                scroll_left,
 332                bounds,
 333                cx,
 334            );
 335        }
 336
 337        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 338        for (replica_id, selections) in &layout.selections {
 339            let style = style.replica_selection_style(*replica_id);
 340            let corner_radius = 0.15 * layout.line_height;
 341
 342            for selection in selections {
 343                self.paint_highlighted_range(
 344                    selection.start..selection.end,
 345                    start_row,
 346                    end_row,
 347                    style.selection,
 348                    corner_radius,
 349                    corner_radius * 2.,
 350                    layout,
 351                    content_origin,
 352                    scroll_top,
 353                    scroll_left,
 354                    bounds,
 355                    cx,
 356                );
 357
 358                if view.show_local_cursors() || *replica_id != local_replica_id {
 359                    let cursor_position = selection.head();
 360                    if (start_row..end_row).contains(&cursor_position.row()) {
 361                        let cursor_row_layout =
 362                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 363                        let x = cursor_row_layout.x_for_index(cursor_position.column() as usize)
 364                            - scroll_left;
 365                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 366                        cursors.push(Cursor {
 367                            color: style.cursor,
 368                            origin: content_origin + vec2f(x, y),
 369                            line_height: layout.line_height,
 370                        });
 371                    }
 372                }
 373            }
 374        }
 375
 376        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 377            // Draw glyphs
 378            for (ix, line) in layout.line_layouts.iter().enumerate() {
 379                let row = start_row + ix as u32;
 380                line.paint(
 381                    content_origin
 382                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 383                    visible_text_bounds,
 384                    layout.line_height,
 385                    cx,
 386                );
 387            }
 388        }
 389
 390        cx.scene.push_layer(Some(bounds));
 391        for cursor in cursors {
 392            cursor.paint(cx);
 393        }
 394        cx.scene.pop_layer();
 395
 396        if let Some((position, completions_list)) = layout.completions.as_mut() {
 397            cx.scene.push_stacking_context(None);
 398
 399            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 400            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 401            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 402            let mut list_origin = content_origin + vec2f(x, y);
 403            let list_height = completions_list.size().y();
 404
 405            if list_origin.y() + list_height > bounds.lower_left().y() {
 406                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 407            }
 408
 409            completions_list.paint(
 410                list_origin,
 411                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 412                cx,
 413            );
 414
 415            cx.scene.pop_stacking_context();
 416        }
 417
 418        cx.scene.pop_layer();
 419    }
 420
 421    fn paint_highlighted_range(
 422        &self,
 423        range: Range<DisplayPoint>,
 424        start_row: u32,
 425        end_row: u32,
 426        color: Color,
 427        corner_radius: f32,
 428        line_end_overshoot: f32,
 429        layout: &LayoutState,
 430        content_origin: Vector2F,
 431        scroll_top: f32,
 432        scroll_left: f32,
 433        bounds: RectF,
 434        cx: &mut PaintContext,
 435    ) {
 436        if range.start != range.end {
 437            let row_range = if range.end.column() == 0 {
 438                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 439            } else {
 440                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 441            };
 442
 443            let highlighted_range = HighlightedRange {
 444                color,
 445                line_height: layout.line_height,
 446                corner_radius,
 447                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 448                    - scroll_top,
 449                lines: row_range
 450                    .into_iter()
 451                    .map(|row| {
 452                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 453                        HighlightedRangeLine {
 454                            start_x: if row == range.start.row() {
 455                                content_origin.x()
 456                                    + line_layout.x_for_index(range.start.column() as usize)
 457                                    - scroll_left
 458                            } else {
 459                                content_origin.x() - scroll_left
 460                            },
 461                            end_x: if row == range.end.row() {
 462                                content_origin.x()
 463                                    + line_layout.x_for_index(range.end.column() as usize)
 464                                    - scroll_left
 465                            } else {
 466                                content_origin.x() + line_layout.width() + line_end_overshoot
 467                                    - scroll_left
 468                            },
 469                        }
 470                    })
 471                    .collect(),
 472            };
 473
 474            highlighted_range.paint(bounds, cx.scene);
 475        }
 476    }
 477
 478    fn paint_blocks(
 479        &mut self,
 480        bounds: RectF,
 481        visible_bounds: RectF,
 482        layout: &mut LayoutState,
 483        cx: &mut PaintContext,
 484    ) {
 485        let scroll_position = layout.snapshot.scroll_position();
 486        let scroll_left = scroll_position.x() * layout.em_width;
 487        let scroll_top = scroll_position.y() * layout.line_height;
 488
 489        for (row, element) in &mut layout.blocks {
 490            let origin = bounds.origin()
 491                + vec2f(-scroll_left, *row as f32 * layout.line_height - scroll_top);
 492            element.paint(origin, visible_bounds, cx);
 493        }
 494    }
 495
 496    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 497        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 498        let style = &self.settings.style;
 499
 500        cx.text_layout_cache
 501            .layout_str(
 502                "1".repeat(digit_count).as_str(),
 503                style.text.font_size,
 504                &[(
 505                    digit_count,
 506                    RunStyle {
 507                        font_id: style.text.font_id,
 508                        color: Color::black(),
 509                        underline: None,
 510                    },
 511                )],
 512            )
 513            .width()
 514    }
 515
 516    fn layout_line_numbers(
 517        &self,
 518        rows: Range<u32>,
 519        active_rows: &BTreeMap<u32, bool>,
 520        snapshot: &EditorSnapshot,
 521        cx: &LayoutContext,
 522    ) -> Vec<Option<text_layout::Line>> {
 523        let style = &self.settings.style;
 524        let include_line_numbers = snapshot.mode == EditorMode::Full;
 525        let mut line_number_layouts = Vec::with_capacity(rows.len());
 526        let mut line_number = String::new();
 527        for (ix, row) in snapshot
 528            .buffer_rows(rows.start)
 529            .take((rows.end - rows.start) as usize)
 530            .enumerate()
 531        {
 532            let display_row = rows.start + ix as u32;
 533            let color = if active_rows.contains_key(&display_row) {
 534                style.line_number_active
 535            } else {
 536                style.line_number
 537            };
 538            if let Some(buffer_row) = row {
 539                if include_line_numbers {
 540                    line_number.clear();
 541                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 542                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 543                        &line_number,
 544                        style.text.font_size,
 545                        &[(
 546                            line_number.len(),
 547                            RunStyle {
 548                                font_id: style.text.font_id,
 549                                color,
 550                                underline: None,
 551                            },
 552                        )],
 553                    )));
 554                }
 555            } else {
 556                line_number_layouts.push(None);
 557            }
 558        }
 559
 560        line_number_layouts
 561    }
 562
 563    fn layout_lines(
 564        &mut self,
 565        mut rows: Range<u32>,
 566        snapshot: &mut EditorSnapshot,
 567        cx: &LayoutContext,
 568    ) -> Vec<text_layout::Line> {
 569        rows.end = cmp::min(rows.end, snapshot.max_point().row() + 1);
 570        if rows.start >= rows.end {
 571            return Vec::new();
 572        }
 573
 574        // When the editor is empty and unfocused, then show the placeholder.
 575        if snapshot.is_empty() && !snapshot.is_focused() {
 576            let placeholder_style = self.settings.style.placeholder_text();
 577            let placeholder_text = snapshot.placeholder_text();
 578            let placeholder_lines = placeholder_text
 579                .as_ref()
 580                .map_or("", AsRef::as_ref)
 581                .split('\n')
 582                .skip(rows.start as usize)
 583                .take(rows.len());
 584            return placeholder_lines
 585                .map(|line| {
 586                    cx.text_layout_cache.layout_str(
 587                        line,
 588                        placeholder_style.font_size,
 589                        &[(
 590                            line.len(),
 591                            RunStyle {
 592                                font_id: placeholder_style.font_id,
 593                                color: placeholder_style.color,
 594                                underline: None,
 595                            },
 596                        )],
 597                    )
 598                })
 599                .collect();
 600        } else {
 601            let style = &self.settings.style;
 602            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 603                let highlight_style = chunk
 604                    .highlight_id
 605                    .and_then(|highlight_id| highlight_id.style(&style.syntax));
 606                let highlight = if let Some(severity) = chunk.diagnostic {
 607                    let diagnostic_style = super::diagnostic_style(severity, true, style);
 608                    let underline = Some(Underline {
 609                        color: diagnostic_style.message.text.color,
 610                        thickness: 1.0.into(),
 611                        squiggly: true,
 612                    });
 613                    if let Some(mut highlight) = highlight_style {
 614                        highlight.underline = underline;
 615                        Some(highlight)
 616                    } else {
 617                        Some(HighlightStyle {
 618                            underline,
 619                            color: style.text.color,
 620                            font_properties: style.text.font_properties,
 621                        })
 622                    }
 623                } else {
 624                    highlight_style
 625                };
 626                (chunk.text, highlight)
 627            });
 628            layout_highlighted_chunks(
 629                chunks,
 630                &style.text,
 631                &cx.text_layout_cache,
 632                &cx.font_cache,
 633                MAX_LINE_LEN,
 634                rows.len() as usize,
 635            )
 636        }
 637    }
 638
 639    fn layout_blocks(
 640        &mut self,
 641        rows: Range<u32>,
 642        snapshot: &EditorSnapshot,
 643        width: f32,
 644        gutter_padding: f32,
 645        gutter_width: f32,
 646        em_width: f32,
 647        text_x: f32,
 648        line_height: f32,
 649        style: &EditorStyle,
 650        line_layouts: &[text_layout::Line],
 651        cx: &mut LayoutContext,
 652    ) -> Vec<(u32, ElementBox)> {
 653        let scroll_x = snapshot.scroll_position.x();
 654        snapshot
 655            .blocks_in_range(rows.clone())
 656            .map(|(block_row, block)| {
 657                let mut element = match block {
 658                    TransformBlock::Custom(block) => {
 659                        let align_to = block
 660                            .position()
 661                            .to_point(&snapshot.buffer_snapshot)
 662                            .to_display_point(snapshot);
 663                        let anchor_x = text_x
 664                            + if rows.contains(&align_to.row()) {
 665                                line_layouts[(align_to.row() - rows.start) as usize]
 666                                    .x_for_index(align_to.column() as usize)
 667                            } else {
 668                                layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 669                                    .x_for_index(align_to.column() as usize)
 670                            };
 671
 672                        block.render(&BlockContext {
 673                            cx,
 674                            anchor_x,
 675                            gutter_padding,
 676                            line_height,
 677                            scroll_x,
 678                            gutter_width,
 679                            em_width,
 680                        })
 681                    }
 682                    TransformBlock::ExcerptHeader { buffer, .. } => {
 683                        let style = &self.settings.style.diagnostic_path_header;
 684                        let font_size =
 685                            (style.text_scale_factor * self.settings.style.text.font_size).round();
 686
 687                        let mut filename = None;
 688                        let mut parent_path = None;
 689                        if let Some(path) = buffer.path() {
 690                            filename = path.file_name().map(|f| f.to_string_lossy().to_string());
 691                            parent_path =
 692                                path.parent().map(|p| p.to_string_lossy().to_string() + "/");
 693                        }
 694
 695                        Flex::row()
 696                            .with_child(
 697                                Label::new(
 698                                    filename.unwrap_or_else(|| "untitled".to_string()),
 699                                    style.filename.text.clone().with_font_size(font_size),
 700                                )
 701                                .contained()
 702                                .with_style(style.filename.container)
 703                                .boxed(),
 704                            )
 705                            .with_children(parent_path.map(|path| {
 706                                Label::new(path, style.path.text.clone().with_font_size(font_size))
 707                                    .contained()
 708                                    .with_style(style.path.container)
 709                                    .boxed()
 710                            }))
 711                            .aligned()
 712                            .left()
 713                            .contained()
 714                            .with_style(style.container)
 715                            .with_padding_left(gutter_padding + scroll_x * em_width)
 716                            .expanded()
 717                            .named("path header block")
 718                    }
 719                };
 720
 721                element.layout(
 722                    SizeConstraint {
 723                        min: Vector2F::zero(),
 724                        max: vec2f(width, block.height() as f32 * line_height),
 725                    },
 726                    cx,
 727                );
 728                (block_row, element)
 729            })
 730            .collect()
 731    }
 732}
 733
 734impl Element for EditorElement {
 735    type LayoutState = LayoutState;
 736    type PaintState = PaintState;
 737
 738    fn layout(
 739        &mut self,
 740        constraint: SizeConstraint,
 741        cx: &mut LayoutContext,
 742    ) -> (Vector2F, Self::LayoutState) {
 743        let mut size = constraint.max;
 744        if size.x().is_infinite() {
 745            unimplemented!("we don't yet handle an infinite width constraint on buffer elements");
 746        }
 747
 748        let snapshot = self.snapshot(cx.app);
 749        let style = self.settings.style.clone();
 750        let line_height = style.text.line_height(cx.font_cache);
 751
 752        let gutter_padding;
 753        let gutter_width;
 754        if snapshot.mode == EditorMode::Full {
 755            gutter_padding = style.text.em_width(cx.font_cache) * style.gutter_padding_factor;
 756            gutter_width = self.max_line_number_width(&snapshot, cx) + gutter_padding * 2.0;
 757        } else {
 758            gutter_padding = 0.0;
 759            gutter_width = 0.0
 760        };
 761
 762        let text_width = size.x() - gutter_width;
 763        let text_offset = vec2f(-style.text.descent(cx.font_cache), 0.);
 764        let em_width = style.text.em_width(cx.font_cache);
 765        let em_advance = style.text.em_advance(cx.font_cache);
 766        let overscroll = vec2f(em_width, 0.);
 767        let wrap_width = match self.settings.soft_wrap {
 768            SoftWrap::None => None,
 769            SoftWrap::EditorWidth => Some(text_width - text_offset.x() - overscroll.x() - em_width),
 770            SoftWrap::Column(column) => Some(column as f32 * em_advance),
 771        };
 772        let snapshot = self.update_view(cx.app, |view, cx| {
 773            if view.set_wrap_width(wrap_width, cx) {
 774                view.snapshot(cx)
 775            } else {
 776                snapshot
 777            }
 778        });
 779
 780        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
 781        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
 782            size.set_y(
 783                scroll_height
 784                    .min(constraint.max_along(Axis::Vertical))
 785                    .max(constraint.min_along(Axis::Vertical))
 786                    .min(line_height * max_lines as f32),
 787            )
 788        } else if size.y().is_infinite() {
 789            size.set_y(scroll_height);
 790        }
 791        let gutter_size = vec2f(gutter_width, size.y());
 792        let text_size = vec2f(text_width, size.y());
 793
 794        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
 795            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
 796            let snapshot = view.snapshot(cx);
 797            (autoscroll_horizontally, snapshot)
 798        });
 799
 800        let scroll_position = snapshot.scroll_position();
 801        let start_row = scroll_position.y() as u32;
 802        let scroll_top = scroll_position.y() * line_height;
 803        let end_row = ((scroll_top + size.y()) / line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 804
 805        let start_anchor = if start_row == 0 {
 806            Anchor::min()
 807        } else {
 808            snapshot
 809                .buffer_snapshot
 810                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
 811        };
 812        let end_anchor = if end_row > snapshot.max_point().row() {
 813            Anchor::max()
 814        } else {
 815            snapshot
 816                .buffer_snapshot
 817                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
 818        };
 819
 820        let mut selections = HashMap::default();
 821        let mut active_rows = BTreeMap::new();
 822        let mut highlighted_rows = None;
 823        let mut highlighted_ranges = Vec::new();
 824        self.update_view(cx.app, |view, cx| {
 825            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
 826
 827            highlighted_rows = view.highlighted_rows();
 828            highlighted_ranges = view.highlighted_ranges_in_range(
 829                start_anchor.clone()..end_anchor.clone(),
 830                &display_map,
 831            );
 832
 833            let local_selections = view
 834                .local_selections_in_range(start_anchor.clone()..end_anchor.clone(), &display_map);
 835            for selection in &local_selections {
 836                let is_empty = selection.start == selection.end;
 837                let selection_start = snapshot.prev_line_boundary(selection.start).1;
 838                let selection_end = snapshot.next_line_boundary(selection.end).1;
 839                for row in cmp::max(selection_start.row(), start_row)
 840                    ..=cmp::min(selection_end.row(), end_row)
 841                {
 842                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
 843                    *contains_non_empty_selection |= !is_empty;
 844                }
 845            }
 846            selections.insert(
 847                view.replica_id(cx),
 848                local_selections
 849                    .into_iter()
 850                    .map(|selection| crate::Selection {
 851                        id: selection.id,
 852                        goal: selection.goal,
 853                        reversed: selection.reversed,
 854                        start: selection.start.to_display_point(&display_map),
 855                        end: selection.end.to_display_point(&display_map),
 856                    })
 857                    .collect(),
 858            );
 859
 860            for (replica_id, selection) in display_map
 861                .buffer_snapshot
 862                .remote_selections_in_range(&(start_anchor..end_anchor))
 863            {
 864                selections
 865                    .entry(replica_id)
 866                    .or_insert(Vec::new())
 867                    .push(crate::Selection {
 868                        id: selection.id,
 869                        goal: selection.goal,
 870                        reversed: selection.reversed,
 871                        start: selection.start.to_display_point(&display_map),
 872                        end: selection.end.to_display_point(&display_map),
 873                    });
 874            }
 875        });
 876
 877        let line_number_layouts =
 878            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
 879
 880        let mut max_visible_line_width = 0.0;
 881        let line_layouts = self.layout_lines(start_row..end_row, &mut snapshot, cx);
 882        for line in &line_layouts {
 883            if line.width() > max_visible_line_width {
 884                max_visible_line_width = line.width();
 885            }
 886        }
 887
 888        let style = self.settings.style.clone();
 889        let longest_line_width = layout_line(
 890            snapshot.longest_row(),
 891            &snapshot,
 892            &style,
 893            cx.text_layout_cache,
 894        )
 895        .width();
 896        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
 897        let em_width = style.text.em_width(cx.font_cache);
 898        let max_row = snapshot.max_point().row();
 899        let scroll_max = vec2f(
 900            ((scroll_width - text_size.x()) / em_width).max(0.0),
 901            max_row.saturating_sub(1) as f32,
 902        );
 903
 904        let mut completions = None;
 905        self.update_view(cx.app, |view, cx| {
 906            let clamped = view.clamp_scroll_left(scroll_max.x());
 907            let autoscrolled;
 908            if autoscroll_horizontally {
 909                autoscrolled = view.autoscroll_horizontally(
 910                    start_row,
 911                    text_size.x(),
 912                    scroll_width,
 913                    em_width,
 914                    &line_layouts,
 915                    cx,
 916                );
 917            } else {
 918                autoscrolled = false;
 919            }
 920
 921            if clamped || autoscrolled {
 922                snapshot = view.snapshot(cx);
 923            }
 924
 925            if view.showing_context_menu() {
 926                let newest_selection_head = view
 927                    .newest_selection::<usize>(&snapshot.buffer_snapshot)
 928                    .head()
 929                    .to_display_point(&snapshot);
 930
 931                if (start_row..end_row).contains(&newest_selection_head.row()) {
 932                    let list = view.render_context_menu(cx).unwrap();
 933                    completions = Some((newest_selection_head, list));
 934                }
 935            }
 936        });
 937
 938        if let Some((_, completions_list)) = completions.as_mut() {
 939            completions_list.layout(
 940                SizeConstraint {
 941                    min: Vector2F::zero(),
 942                    max: vec2f(
 943                        f32::INFINITY,
 944                        (12. * line_height).min((size.y() - line_height) / 2.),
 945                    ),
 946                },
 947                cx,
 948            );
 949        }
 950
 951        let blocks = self.layout_blocks(
 952            start_row..end_row,
 953            &snapshot,
 954            size.x().max(scroll_width + gutter_width),
 955            gutter_padding,
 956            gutter_width,
 957            em_width,
 958            gutter_width + text_offset.x(),
 959            line_height,
 960            &style,
 961            &line_layouts,
 962            cx,
 963        );
 964
 965        (
 966            size,
 967            LayoutState {
 968                size,
 969                scroll_max,
 970                gutter_size,
 971                gutter_padding,
 972                text_size,
 973                text_offset,
 974                snapshot,
 975                active_rows,
 976                highlighted_rows,
 977                highlighted_ranges,
 978                line_layouts,
 979                line_number_layouts,
 980                blocks,
 981                line_height,
 982                em_width,
 983                em_advance,
 984                selections,
 985                completions,
 986            },
 987        )
 988    }
 989
 990    fn paint(
 991        &mut self,
 992        bounds: RectF,
 993        visible_bounds: RectF,
 994        layout: &mut Self::LayoutState,
 995        cx: &mut PaintContext,
 996    ) -> Self::PaintState {
 997        cx.scene.push_layer(Some(bounds));
 998
 999        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1000        let text_bounds = RectF::new(
1001            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1002            layout.text_size,
1003        );
1004
1005        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1006        if layout.gutter_size.x() > 0. {
1007            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1008        }
1009        self.paint_text(text_bounds, visible_bounds, layout, cx);
1010
1011        if !layout.blocks.is_empty() {
1012            cx.scene.push_layer(Some(bounds));
1013            self.paint_blocks(bounds, visible_bounds, layout, cx);
1014            cx.scene.pop_layer();
1015        }
1016
1017        cx.scene.pop_layer();
1018
1019        PaintState {
1020            bounds,
1021            gutter_bounds,
1022            text_bounds,
1023        }
1024    }
1025
1026    fn dispatch_event(
1027        &mut self,
1028        event: &Event,
1029        _: RectF,
1030        layout: &mut LayoutState,
1031        paint: &mut PaintState,
1032        cx: &mut EventContext,
1033    ) -> bool {
1034        if let Some((_, completion_list)) = &mut layout.completions {
1035            if completion_list.dispatch_event(event, cx) {
1036                return true;
1037            }
1038        }
1039
1040        match event {
1041            Event::LeftMouseDown {
1042                position,
1043                alt,
1044                shift,
1045                click_count,
1046                ..
1047            } => self.mouse_down(*position, *alt, *shift, *click_count, layout, paint, cx),
1048            Event::LeftMouseUp { position } => self.mouse_up(*position, cx),
1049            Event::LeftMouseDragged { position } => {
1050                self.mouse_dragged(*position, layout, paint, cx)
1051            }
1052            Event::ScrollWheel {
1053                position,
1054                delta,
1055                precise,
1056            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1057            Event::KeyDown {
1058                chars, keystroke, ..
1059            } => self.key_down(chars, keystroke, cx),
1060            _ => false,
1061        }
1062    }
1063
1064    fn debug(
1065        &self,
1066        bounds: RectF,
1067        _: &Self::LayoutState,
1068        _: &Self::PaintState,
1069        _: &gpui::DebugContext,
1070    ) -> json::Value {
1071        json!({
1072            "type": "BufferElement",
1073            "bounds": bounds.to_json()
1074        })
1075    }
1076}
1077
1078pub struct LayoutState {
1079    size: Vector2F,
1080    scroll_max: Vector2F,
1081    gutter_size: Vector2F,
1082    gutter_padding: f32,
1083    text_size: Vector2F,
1084    snapshot: EditorSnapshot,
1085    active_rows: BTreeMap<u32, bool>,
1086    highlighted_rows: Option<Range<u32>>,
1087    line_layouts: Vec<text_layout::Line>,
1088    line_number_layouts: Vec<Option<text_layout::Line>>,
1089    blocks: Vec<(u32, ElementBox)>,
1090    line_height: f32,
1091    em_width: f32,
1092    em_advance: f32,
1093    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1094    selections: HashMap<ReplicaId, Vec<text::Selection<DisplayPoint>>>,
1095    text_offset: Vector2F,
1096    completions: Option<(DisplayPoint, ElementBox)>,
1097}
1098
1099fn layout_line(
1100    row: u32,
1101    snapshot: &EditorSnapshot,
1102    style: &EditorStyle,
1103    layout_cache: &TextLayoutCache,
1104) -> text_layout::Line {
1105    let mut line = snapshot.line(row);
1106
1107    if line.len() > MAX_LINE_LEN {
1108        let mut len = MAX_LINE_LEN;
1109        while !line.is_char_boundary(len) {
1110            len -= 1;
1111        }
1112        line.truncate(len);
1113    }
1114
1115    layout_cache.layout_str(
1116        &line,
1117        style.text.font_size,
1118        &[(
1119            snapshot.line_len(row) as usize,
1120            RunStyle {
1121                font_id: style.text.font_id,
1122                color: Color::black(),
1123                underline: None,
1124            },
1125        )],
1126    )
1127}
1128
1129pub struct PaintState {
1130    bounds: RectF,
1131    gutter_bounds: RectF,
1132    text_bounds: RectF,
1133}
1134
1135impl PaintState {
1136    fn point_for_position(
1137        &self,
1138        snapshot: &EditorSnapshot,
1139        layout: &LayoutState,
1140        position: Vector2F,
1141    ) -> (DisplayPoint, u32) {
1142        let scroll_position = snapshot.scroll_position();
1143        let position = position - self.text_bounds.origin();
1144        let y = position.y().max(0.0).min(layout.size.y());
1145        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1146        let row = cmp::min(row, snapshot.max_point().row());
1147        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1148        let x = position.x() + (scroll_position.x() * layout.em_width);
1149
1150        let column = if x >= 0.0 {
1151            line.index_for_x(x)
1152                .map(|ix| ix as u32)
1153                .unwrap_or_else(|| snapshot.line_len(row))
1154        } else {
1155            0
1156        };
1157        let overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1158
1159        (DisplayPoint::new(row, column), overshoot)
1160    }
1161}
1162
1163struct Cursor {
1164    origin: Vector2F,
1165    line_height: f32,
1166    color: Color,
1167}
1168
1169impl Cursor {
1170    fn paint(&self, cx: &mut PaintContext) {
1171        cx.scene.push_quad(Quad {
1172            bounds: RectF::new(self.origin, vec2f(2.0, self.line_height)),
1173            background: Some(self.color),
1174            border: Border::new(0., Color::black()),
1175            corner_radius: 0.,
1176        });
1177    }
1178}
1179
1180#[derive(Debug)]
1181struct HighlightedRange {
1182    start_y: f32,
1183    line_height: f32,
1184    lines: Vec<HighlightedRangeLine>,
1185    color: Color,
1186    corner_radius: f32,
1187}
1188
1189#[derive(Debug)]
1190struct HighlightedRangeLine {
1191    start_x: f32,
1192    end_x: f32,
1193}
1194
1195impl HighlightedRange {
1196    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1197        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1198            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1199            self.paint_lines(
1200                self.start_y + self.line_height,
1201                &self.lines[1..],
1202                bounds,
1203                scene,
1204            );
1205        } else {
1206            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1207        }
1208    }
1209
1210    fn paint_lines(
1211        &self,
1212        start_y: f32,
1213        lines: &[HighlightedRangeLine],
1214        bounds: RectF,
1215        scene: &mut Scene,
1216    ) {
1217        if lines.is_empty() {
1218            return;
1219        }
1220
1221        let mut path = PathBuilder::new();
1222        let first_line = lines.first().unwrap();
1223        let last_line = lines.last().unwrap();
1224
1225        let first_top_left = vec2f(first_line.start_x, start_y);
1226        let first_top_right = vec2f(first_line.end_x, start_y);
1227
1228        let curve_height = vec2f(0., self.corner_radius);
1229        let curve_width = |start_x: f32, end_x: f32| {
1230            let max = (end_x - start_x) / 2.;
1231            let width = if max < self.corner_radius {
1232                max
1233            } else {
1234                self.corner_radius
1235            };
1236
1237            vec2f(width, 0.)
1238        };
1239
1240        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1241        path.reset(first_top_right - top_curve_width);
1242        path.curve_to(first_top_right + curve_height, first_top_right);
1243
1244        let mut iter = lines.iter().enumerate().peekable();
1245        while let Some((ix, line)) = iter.next() {
1246            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1247
1248            if let Some((_, next_line)) = iter.peek() {
1249                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1250
1251                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1252                    Ordering::Equal => {
1253                        path.line_to(bottom_right);
1254                    }
1255                    Ordering::Less => {
1256                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1257                        path.line_to(bottom_right - curve_height);
1258                        if self.corner_radius > 0. {
1259                            path.curve_to(bottom_right - curve_width, bottom_right);
1260                        }
1261                        path.line_to(next_top_right + curve_width);
1262                        if self.corner_radius > 0. {
1263                            path.curve_to(next_top_right + curve_height, next_top_right);
1264                        }
1265                    }
1266                    Ordering::Greater => {
1267                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1268                        path.line_to(bottom_right - curve_height);
1269                        if self.corner_radius > 0. {
1270                            path.curve_to(bottom_right + curve_width, bottom_right);
1271                        }
1272                        path.line_to(next_top_right - curve_width);
1273                        if self.corner_radius > 0. {
1274                            path.curve_to(next_top_right + curve_height, next_top_right);
1275                        }
1276                    }
1277                }
1278            } else {
1279                let curve_width = curve_width(line.start_x, line.end_x);
1280                path.line_to(bottom_right - curve_height);
1281                if self.corner_radius > 0. {
1282                    path.curve_to(bottom_right - curve_width, bottom_right);
1283                }
1284
1285                let bottom_left = vec2f(line.start_x, bottom_right.y());
1286                path.line_to(bottom_left + curve_width);
1287                if self.corner_radius > 0. {
1288                    path.curve_to(bottom_left - curve_height, bottom_left);
1289                }
1290            }
1291        }
1292
1293        if first_line.start_x > last_line.start_x {
1294            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1295            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1296            path.line_to(second_top_left + curve_height);
1297            if self.corner_radius > 0. {
1298                path.curve_to(second_top_left + curve_width, second_top_left);
1299            }
1300            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1301            path.line_to(first_bottom_left - curve_width);
1302            if self.corner_radius > 0. {
1303                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1304            }
1305        }
1306
1307        path.line_to(first_top_left + curve_height);
1308        if self.corner_radius > 0. {
1309            path.curve_to(first_top_left + top_curve_width, first_top_left);
1310        }
1311        path.line_to(first_top_right - top_curve_width);
1312
1313        scene.push_path(path.build(self.color, Some(bounds)));
1314    }
1315}
1316
1317fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1318    delta.powf(1.5) / 100.0
1319}
1320
1321fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1322    delta.powf(1.2) / 300.0
1323}
1324
1325#[cfg(test)]
1326mod tests {
1327    use super::*;
1328    use crate::{Editor, EditorSettings, MultiBuffer};
1329    use std::sync::Arc;
1330    use util::test::sample_text;
1331
1332    #[gpui::test]
1333    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1334        let settings = EditorSettings::test(cx);
1335        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1336        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1337            Editor::for_buffer(
1338                buffer,
1339                {
1340                    let settings = settings.clone();
1341                    Arc::new(move |_| settings.clone())
1342                },
1343                None,
1344                cx,
1345            )
1346        });
1347        let element = EditorElement::new(editor.downgrade(), settings);
1348
1349        let layouts = editor.update(cx, |editor, cx| {
1350            let snapshot = editor.snapshot(cx);
1351            let mut presenter = cx.build_presenter(window_id, 30.);
1352            let mut layout_cx = presenter.build_layout_context(false, cx);
1353            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1354        });
1355        assert_eq!(layouts.len(), 6);
1356    }
1357}