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: &mut 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        if let Some((row, indicator)) = layout.code_actions_indicator.as_mut() {
 300            let mut x = bounds.width() - layout.gutter_padding;
 301            let mut y = *row as f32 * layout.line_height - scroll_top;
 302            x += ((layout.gutter_padding + layout.gutter_margin) - indicator.size().x()) / 2.;
 303            y += (layout.line_height - indicator.size().y()) / 2.;
 304            indicator.paint(bounds.origin() + vec2f(x, y), visible_bounds, cx);
 305        }
 306    }
 307
 308    fn paint_text(
 309        &mut self,
 310        bounds: RectF,
 311        visible_bounds: RectF,
 312        layout: &mut LayoutState,
 313        cx: &mut PaintContext,
 314    ) {
 315        let view = self.view(cx.app);
 316        let style = &self.settings.style;
 317        let local_replica_id = view.replica_id(cx);
 318        let scroll_position = layout.snapshot.scroll_position();
 319        let start_row = scroll_position.y() as u32;
 320        let scroll_top = scroll_position.y() * layout.line_height;
 321        let end_row = ((scroll_top + bounds.height()) / layout.line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 322        let max_glyph_width = layout.em_width;
 323        let scroll_left = scroll_position.x() * max_glyph_width;
 324        let content_origin = bounds.origin() + vec2f(layout.gutter_margin, 0.);
 325
 326        cx.scene.push_layer(Some(bounds));
 327
 328        for (range, color) in &layout.highlighted_ranges {
 329            self.paint_highlighted_range(
 330                range.clone(),
 331                start_row,
 332                end_row,
 333                *color,
 334                0.,
 335                0.15 * layout.line_height,
 336                layout,
 337                content_origin,
 338                scroll_top,
 339                scroll_left,
 340                bounds,
 341                cx,
 342            );
 343        }
 344
 345        let mut cursors = SmallVec::<[Cursor; 32]>::new();
 346        for (replica_id, selections) in &layout.selections {
 347            let style = style.replica_selection_style(*replica_id);
 348            let corner_radius = 0.15 * layout.line_height;
 349
 350            for selection in selections {
 351                self.paint_highlighted_range(
 352                    selection.start..selection.end,
 353                    start_row,
 354                    end_row,
 355                    style.selection,
 356                    corner_radius,
 357                    corner_radius * 2.,
 358                    layout,
 359                    content_origin,
 360                    scroll_top,
 361                    scroll_left,
 362                    bounds,
 363                    cx,
 364                );
 365
 366                if view.show_local_cursors() || *replica_id != local_replica_id {
 367                    let cursor_position = selection.head();
 368                    if (start_row..end_row).contains(&cursor_position.row()) {
 369                        let cursor_row_layout =
 370                            &layout.line_layouts[(cursor_position.row() - start_row) as usize];
 371                        let x = cursor_row_layout.x_for_index(cursor_position.column() as usize)
 372                            - scroll_left;
 373                        let y = cursor_position.row() as f32 * layout.line_height - scroll_top;
 374                        cursors.push(Cursor {
 375                            color: style.cursor,
 376                            origin: content_origin + vec2f(x, y),
 377                            line_height: layout.line_height,
 378                        });
 379                    }
 380                }
 381            }
 382        }
 383
 384        if let Some(visible_text_bounds) = bounds.intersection(visible_bounds) {
 385            // Draw glyphs
 386            for (ix, line) in layout.line_layouts.iter().enumerate() {
 387                let row = start_row + ix as u32;
 388                line.paint(
 389                    content_origin
 390                        + vec2f(-scroll_left, row as f32 * layout.line_height - scroll_top),
 391                    visible_text_bounds,
 392                    layout.line_height,
 393                    cx,
 394                );
 395            }
 396        }
 397
 398        cx.scene.push_layer(Some(bounds));
 399        for cursor in cursors {
 400            cursor.paint(cx);
 401        }
 402        cx.scene.pop_layer();
 403
 404        if let Some((position, context_menu)) = layout.context_menu.as_mut() {
 405            cx.scene.push_stacking_context(None);
 406
 407            let cursor_row_layout = &layout.line_layouts[(position.row() - start_row) as usize];
 408            let x = cursor_row_layout.x_for_index(position.column() as usize) - scroll_left;
 409            let y = (position.row() + 1) as f32 * layout.line_height - scroll_top;
 410            let mut list_origin = content_origin + vec2f(x, y);
 411            let list_height = context_menu.size().y();
 412
 413            if list_origin.y() + list_height > bounds.lower_left().y() {
 414                list_origin.set_y(list_origin.y() - layout.line_height - list_height);
 415            }
 416
 417            context_menu.paint(
 418                list_origin,
 419                RectF::from_points(Vector2F::zero(), vec2f(f32::MAX, f32::MAX)), // Let content bleed outside of editor
 420                cx,
 421            );
 422
 423            cx.scene.pop_stacking_context();
 424        }
 425
 426        cx.scene.pop_layer();
 427    }
 428
 429    fn paint_highlighted_range(
 430        &self,
 431        range: Range<DisplayPoint>,
 432        start_row: u32,
 433        end_row: u32,
 434        color: Color,
 435        corner_radius: f32,
 436        line_end_overshoot: f32,
 437        layout: &LayoutState,
 438        content_origin: Vector2F,
 439        scroll_top: f32,
 440        scroll_left: f32,
 441        bounds: RectF,
 442        cx: &mut PaintContext,
 443    ) {
 444        if range.start != range.end {
 445            let row_range = if range.end.column() == 0 {
 446                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row(), end_row)
 447            } else {
 448                cmp::max(range.start.row(), start_row)..cmp::min(range.end.row() + 1, end_row)
 449            };
 450
 451            let highlighted_range = HighlightedRange {
 452                color,
 453                line_height: layout.line_height,
 454                corner_radius,
 455                start_y: content_origin.y() + row_range.start as f32 * layout.line_height
 456                    - scroll_top,
 457                lines: row_range
 458                    .into_iter()
 459                    .map(|row| {
 460                        let line_layout = &layout.line_layouts[(row - start_row) as usize];
 461                        HighlightedRangeLine {
 462                            start_x: if row == range.start.row() {
 463                                content_origin.x()
 464                                    + line_layout.x_for_index(range.start.column() as usize)
 465                                    - scroll_left
 466                            } else {
 467                                content_origin.x() - scroll_left
 468                            },
 469                            end_x: if row == range.end.row() {
 470                                content_origin.x()
 471                                    + line_layout.x_for_index(range.end.column() as usize)
 472                                    - scroll_left
 473                            } else {
 474                                content_origin.x() + line_layout.width() + line_end_overshoot
 475                                    - scroll_left
 476                            },
 477                        }
 478                    })
 479                    .collect(),
 480            };
 481
 482            highlighted_range.paint(bounds, cx.scene);
 483        }
 484    }
 485
 486    fn paint_blocks(
 487        &mut self,
 488        bounds: RectF,
 489        visible_bounds: RectF,
 490        layout: &mut LayoutState,
 491        cx: &mut PaintContext,
 492    ) {
 493        let scroll_position = layout.snapshot.scroll_position();
 494        let scroll_left = scroll_position.x() * layout.em_width;
 495        let scroll_top = scroll_position.y() * layout.line_height;
 496
 497        for (row, element) in &mut layout.blocks {
 498            let origin = bounds.origin()
 499                + vec2f(-scroll_left, *row as f32 * layout.line_height - scroll_top);
 500            element.paint(origin, visible_bounds, cx);
 501        }
 502    }
 503
 504    fn max_line_number_width(&self, snapshot: &EditorSnapshot, cx: &LayoutContext) -> f32 {
 505        let digit_count = (snapshot.max_buffer_row() as f32).log10().floor() as usize + 1;
 506        let style = &self.settings.style;
 507
 508        cx.text_layout_cache
 509            .layout_str(
 510                "1".repeat(digit_count).as_str(),
 511                style.text.font_size,
 512                &[(
 513                    digit_count,
 514                    RunStyle {
 515                        font_id: style.text.font_id,
 516                        color: Color::black(),
 517                        underline: None,
 518                    },
 519                )],
 520            )
 521            .width()
 522    }
 523
 524    fn layout_line_numbers(
 525        &self,
 526        rows: Range<u32>,
 527        active_rows: &BTreeMap<u32, bool>,
 528        snapshot: &EditorSnapshot,
 529        cx: &LayoutContext,
 530    ) -> Vec<Option<text_layout::Line>> {
 531        let style = &self.settings.style;
 532        let include_line_numbers = snapshot.mode == EditorMode::Full;
 533        let mut line_number_layouts = Vec::with_capacity(rows.len());
 534        let mut line_number = String::new();
 535        for (ix, row) in snapshot
 536            .buffer_rows(rows.start)
 537            .take((rows.end - rows.start) as usize)
 538            .enumerate()
 539        {
 540            let display_row = rows.start + ix as u32;
 541            let color = if active_rows.contains_key(&display_row) {
 542                style.line_number_active
 543            } else {
 544                style.line_number
 545            };
 546            if let Some(buffer_row) = row {
 547                if include_line_numbers {
 548                    line_number.clear();
 549                    write!(&mut line_number, "{}", buffer_row + 1).unwrap();
 550                    line_number_layouts.push(Some(cx.text_layout_cache.layout_str(
 551                        &line_number,
 552                        style.text.font_size,
 553                        &[(
 554                            line_number.len(),
 555                            RunStyle {
 556                                font_id: style.text.font_id,
 557                                color,
 558                                underline: None,
 559                            },
 560                        )],
 561                    )));
 562                }
 563            } else {
 564                line_number_layouts.push(None);
 565            }
 566        }
 567
 568        line_number_layouts
 569    }
 570
 571    fn layout_lines(
 572        &mut self,
 573        mut rows: Range<u32>,
 574        snapshot: &mut EditorSnapshot,
 575        cx: &LayoutContext,
 576    ) -> Vec<text_layout::Line> {
 577        rows.end = cmp::min(rows.end, snapshot.max_point().row() + 1);
 578        if rows.start >= rows.end {
 579            return Vec::new();
 580        }
 581
 582        // When the editor is empty and unfocused, then show the placeholder.
 583        if snapshot.is_empty() && !snapshot.is_focused() {
 584            let placeholder_style = self.settings.style.placeholder_text();
 585            let placeholder_text = snapshot.placeholder_text();
 586            let placeholder_lines = placeholder_text
 587                .as_ref()
 588                .map_or("", AsRef::as_ref)
 589                .split('\n')
 590                .skip(rows.start as usize)
 591                .take(rows.len());
 592            return placeholder_lines
 593                .map(|line| {
 594                    cx.text_layout_cache.layout_str(
 595                        line,
 596                        placeholder_style.font_size,
 597                        &[(
 598                            line.len(),
 599                            RunStyle {
 600                                font_id: placeholder_style.font_id,
 601                                color: placeholder_style.color,
 602                                underline: None,
 603                            },
 604                        )],
 605                    )
 606                })
 607                .collect();
 608        } else {
 609            let style = &self.settings.style;
 610            let chunks = snapshot.chunks(rows.clone(), true).map(|chunk| {
 611                let highlight_style = chunk
 612                    .highlight_id
 613                    .and_then(|highlight_id| highlight_id.style(&style.syntax));
 614                let highlight = if let Some(severity) = chunk.diagnostic {
 615                    let diagnostic_style = super::diagnostic_style(severity, true, style);
 616                    let underline = Some(Underline {
 617                        color: diagnostic_style.message.text.color,
 618                        thickness: 1.0.into(),
 619                        squiggly: true,
 620                    });
 621                    if let Some(mut highlight) = highlight_style {
 622                        highlight.underline = underline;
 623                        Some(highlight)
 624                    } else {
 625                        Some(HighlightStyle {
 626                            underline,
 627                            color: style.text.color,
 628                            font_properties: style.text.font_properties,
 629                        })
 630                    }
 631                } else {
 632                    highlight_style
 633                };
 634                (chunk.text, highlight)
 635            });
 636            layout_highlighted_chunks(
 637                chunks,
 638                &style.text,
 639                &cx.text_layout_cache,
 640                &cx.font_cache,
 641                MAX_LINE_LEN,
 642                rows.len() as usize,
 643            )
 644        }
 645    }
 646
 647    fn layout_blocks(
 648        &mut self,
 649        rows: Range<u32>,
 650        snapshot: &EditorSnapshot,
 651        width: f32,
 652        gutter_padding: f32,
 653        gutter_width: f32,
 654        em_width: f32,
 655        text_x: f32,
 656        line_height: f32,
 657        style: &EditorStyle,
 658        line_layouts: &[text_layout::Line],
 659        cx: &mut LayoutContext,
 660    ) -> Vec<(u32, ElementBox)> {
 661        let scroll_x = snapshot.scroll_position.x();
 662        snapshot
 663            .blocks_in_range(rows.clone())
 664            .map(|(block_row, block)| {
 665                let mut element = match block {
 666                    TransformBlock::Custom(block) => {
 667                        let align_to = block
 668                            .position()
 669                            .to_point(&snapshot.buffer_snapshot)
 670                            .to_display_point(snapshot);
 671                        let anchor_x = text_x
 672                            + if rows.contains(&align_to.row()) {
 673                                line_layouts[(align_to.row() - rows.start) as usize]
 674                                    .x_for_index(align_to.column() as usize)
 675                            } else {
 676                                layout_line(align_to.row(), snapshot, style, cx.text_layout_cache)
 677                                    .x_for_index(align_to.column() as usize)
 678                            };
 679
 680                        block.render(&BlockContext {
 681                            cx,
 682                            anchor_x,
 683                            gutter_padding,
 684                            line_height,
 685                            scroll_x,
 686                            gutter_width,
 687                            em_width,
 688                        })
 689                    }
 690                    TransformBlock::ExcerptHeader {
 691                        buffer,
 692                        starts_new_buffer,
 693                        ..
 694                    } => {
 695                        if *starts_new_buffer {
 696                            let style = &self.settings.style.diagnostic_path_header;
 697                            let font_size = (style.text_scale_factor
 698                                * self.settings.style.text.font_size)
 699                                .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.settings.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.settings.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 wrap_width = match self.settings.soft_wrap {
 795            SoftWrap::None => None,
 796            SoftWrap::EditorWidth => Some(text_width - gutter_margin - overscroll.x() - em_width),
 797            SoftWrap::Column(column) => Some(column as f32 * em_advance),
 798        };
 799        let snapshot = self.update_view(cx.app, |view, cx| {
 800            if view.set_wrap_width(wrap_width, cx) {
 801                view.snapshot(cx)
 802            } else {
 803                snapshot
 804            }
 805        });
 806
 807        let scroll_height = (snapshot.max_point().row() + 1) as f32 * line_height;
 808        if let EditorMode::AutoHeight { max_lines } = snapshot.mode {
 809            size.set_y(
 810                scroll_height
 811                    .min(constraint.max_along(Axis::Vertical))
 812                    .max(constraint.min_along(Axis::Vertical))
 813                    .min(line_height * max_lines as f32),
 814            )
 815        } else if size.y().is_infinite() {
 816            size.set_y(scroll_height);
 817        }
 818        let gutter_size = vec2f(gutter_width, size.y());
 819        let text_size = vec2f(text_width, size.y());
 820
 821        let (autoscroll_horizontally, mut snapshot) = self.update_view(cx.app, |view, cx| {
 822            let autoscroll_horizontally = view.autoscroll_vertically(size.y(), line_height, cx);
 823            let snapshot = view.snapshot(cx);
 824            (autoscroll_horizontally, snapshot)
 825        });
 826
 827        let scroll_position = snapshot.scroll_position();
 828        let start_row = scroll_position.y() as u32;
 829        let scroll_top = scroll_position.y() * line_height;
 830        let end_row = ((scroll_top + size.y()) / line_height).ceil() as u32 + 1; // Add 1 to ensure selections bleed off screen
 831
 832        let start_anchor = if start_row == 0 {
 833            Anchor::min()
 834        } else {
 835            snapshot
 836                .buffer_snapshot
 837                .anchor_before(DisplayPoint::new(start_row, 0).to_offset(&snapshot, Bias::Left))
 838        };
 839        let end_anchor = if end_row > snapshot.max_point().row() {
 840            Anchor::max()
 841        } else {
 842            snapshot
 843                .buffer_snapshot
 844                .anchor_before(DisplayPoint::new(end_row, 0).to_offset(&snapshot, Bias::Right))
 845        };
 846
 847        let mut selections = HashMap::default();
 848        let mut active_rows = BTreeMap::new();
 849        let mut highlighted_rows = None;
 850        let mut highlighted_ranges = Vec::new();
 851        self.update_view(cx.app, |view, cx| {
 852            let display_map = view.display_map.update(cx, |map, cx| map.snapshot(cx));
 853
 854            highlighted_rows = view.highlighted_rows();
 855            highlighted_ranges = view.highlighted_ranges_in_range(
 856                start_anchor.clone()..end_anchor.clone(),
 857                &display_map,
 858            );
 859
 860            let local_selections = view
 861                .local_selections_in_range(start_anchor.clone()..end_anchor.clone(), &display_map);
 862            for selection in &local_selections {
 863                let is_empty = selection.start == selection.end;
 864                let selection_start = snapshot.prev_line_boundary(selection.start).1;
 865                let selection_end = snapshot.next_line_boundary(selection.end).1;
 866                for row in cmp::max(selection_start.row(), start_row)
 867                    ..=cmp::min(selection_end.row(), end_row)
 868                {
 869                    let contains_non_empty_selection = active_rows.entry(row).or_insert(!is_empty);
 870                    *contains_non_empty_selection |= !is_empty;
 871                }
 872            }
 873            selections.insert(
 874                view.replica_id(cx),
 875                local_selections
 876                    .into_iter()
 877                    .map(|selection| crate::Selection {
 878                        id: selection.id,
 879                        goal: selection.goal,
 880                        reversed: selection.reversed,
 881                        start: selection.start.to_display_point(&display_map),
 882                        end: selection.end.to_display_point(&display_map),
 883                    })
 884                    .collect(),
 885            );
 886
 887            for (replica_id, selection) in display_map
 888                .buffer_snapshot
 889                .remote_selections_in_range(&(start_anchor..end_anchor))
 890            {
 891                selections
 892                    .entry(replica_id)
 893                    .or_insert(Vec::new())
 894                    .push(crate::Selection {
 895                        id: selection.id,
 896                        goal: selection.goal,
 897                        reversed: selection.reversed,
 898                        start: selection.start.to_display_point(&display_map),
 899                        end: selection.end.to_display_point(&display_map),
 900                    });
 901            }
 902        });
 903
 904        let line_number_layouts =
 905            self.layout_line_numbers(start_row..end_row, &active_rows, &snapshot, cx);
 906
 907        let mut max_visible_line_width = 0.0;
 908        let line_layouts = self.layout_lines(start_row..end_row, &mut snapshot, cx);
 909        for line in &line_layouts {
 910            if line.width() > max_visible_line_width {
 911                max_visible_line_width = line.width();
 912            }
 913        }
 914
 915        let style = self.settings.style.clone();
 916        let longest_line_width = layout_line(
 917            snapshot.longest_row(),
 918            &snapshot,
 919            &style,
 920            cx.text_layout_cache,
 921        )
 922        .width();
 923        let scroll_width = longest_line_width.max(max_visible_line_width) + overscroll.x();
 924        let em_width = style.text.em_width(cx.font_cache);
 925        let max_row = snapshot.max_point().row();
 926        let scroll_max = vec2f(
 927            ((scroll_width - text_size.x()) / em_width).max(0.0),
 928            max_row.saturating_sub(1) as f32,
 929        );
 930
 931        let mut context_menu = None;
 932        let mut code_actions_indicator = None;
 933        self.update_view(cx.app, |view, cx| {
 934            let clamped = view.clamp_scroll_left(scroll_max.x());
 935            let autoscrolled;
 936            if autoscroll_horizontally {
 937                autoscrolled = view.autoscroll_horizontally(
 938                    start_row,
 939                    text_size.x(),
 940                    scroll_width,
 941                    em_width,
 942                    &line_layouts,
 943                    cx,
 944                );
 945            } else {
 946                autoscrolled = false;
 947            }
 948
 949            if clamped || autoscrolled {
 950                snapshot = view.snapshot(cx);
 951            }
 952
 953            let newest_selection_head = view
 954                .newest_selection::<usize>(&snapshot.buffer_snapshot)
 955                .head()
 956                .to_display_point(&snapshot);
 957
 958            if (start_row..end_row).contains(&newest_selection_head.row()) {
 959                if view.context_menu_visible() {
 960                    context_menu = view.render_context_menu(newest_selection_head, cx);
 961                }
 962
 963                code_actions_indicator = view
 964                    .render_code_actions_indicator(cx)
 965                    .map(|indicator| (newest_selection_head.row(), indicator));
 966            }
 967        });
 968
 969        if let Some((_, context_menu)) = context_menu.as_mut() {
 970            context_menu.layout(
 971                SizeConstraint {
 972                    min: Vector2F::zero(),
 973                    max: vec2f(
 974                        f32::INFINITY,
 975                        (12. * line_height).min((size.y() - line_height) / 2.),
 976                    ),
 977                },
 978                cx,
 979            );
 980        }
 981
 982        if let Some((_, indicator)) = code_actions_indicator.as_mut() {
 983            indicator.layout(
 984                SizeConstraint::strict_along(Axis::Vertical, line_height * 0.618),
 985                cx,
 986            );
 987        }
 988
 989        let blocks = self.layout_blocks(
 990            start_row..end_row,
 991            &snapshot,
 992            size.x().max(scroll_width + gutter_width),
 993            gutter_padding,
 994            gutter_width,
 995            em_width,
 996            gutter_width + gutter_margin,
 997            line_height,
 998            &style,
 999            &line_layouts,
1000            cx,
1001        );
1002
1003        (
1004            size,
1005            LayoutState {
1006                size,
1007                scroll_max,
1008                gutter_size,
1009                gutter_padding,
1010                text_size,
1011                gutter_margin,
1012                snapshot,
1013                active_rows,
1014                highlighted_rows,
1015                highlighted_ranges,
1016                line_layouts,
1017                line_number_layouts,
1018                blocks,
1019                line_height,
1020                em_width,
1021                em_advance,
1022                selections,
1023                context_menu,
1024                code_actions_indicator,
1025            },
1026        )
1027    }
1028
1029    fn paint(
1030        &mut self,
1031        bounds: RectF,
1032        visible_bounds: RectF,
1033        layout: &mut Self::LayoutState,
1034        cx: &mut PaintContext,
1035    ) -> Self::PaintState {
1036        cx.scene.push_layer(Some(bounds));
1037
1038        let gutter_bounds = RectF::new(bounds.origin(), layout.gutter_size);
1039        let text_bounds = RectF::new(
1040            bounds.origin() + vec2f(layout.gutter_size.x(), 0.0),
1041            layout.text_size,
1042        );
1043
1044        self.paint_background(gutter_bounds, text_bounds, layout, cx);
1045        if layout.gutter_size.x() > 0. {
1046            self.paint_gutter(gutter_bounds, visible_bounds, layout, cx);
1047        }
1048        self.paint_text(text_bounds, visible_bounds, layout, cx);
1049
1050        if !layout.blocks.is_empty() {
1051            cx.scene.push_layer(Some(bounds));
1052            self.paint_blocks(bounds, visible_bounds, layout, cx);
1053            cx.scene.pop_layer();
1054        }
1055
1056        cx.scene.pop_layer();
1057
1058        PaintState {
1059            bounds,
1060            gutter_bounds,
1061            text_bounds,
1062        }
1063    }
1064
1065    fn dispatch_event(
1066        &mut self,
1067        event: &Event,
1068        _: RectF,
1069        layout: &mut LayoutState,
1070        paint: &mut PaintState,
1071        cx: &mut EventContext,
1072    ) -> bool {
1073        if let Some((_, context_menu)) = &mut layout.context_menu {
1074            if context_menu.dispatch_event(event, cx) {
1075                return true;
1076            }
1077        }
1078
1079        if let Some((_, indicator)) = &mut layout.code_actions_indicator {
1080            if indicator.dispatch_event(event, cx) {
1081                return true;
1082            }
1083        }
1084
1085        for (_, block) in &mut layout.blocks {
1086            if block.dispatch_event(event, cx) {
1087                return true;
1088            }
1089        }
1090
1091        match event {
1092            Event::LeftMouseDown {
1093                position,
1094                alt,
1095                shift,
1096                click_count,
1097                ..
1098            } => self.mouse_down(*position, *alt, *shift, *click_count, layout, paint, cx),
1099            Event::LeftMouseUp { position } => self.mouse_up(*position, cx),
1100            Event::LeftMouseDragged { position } => {
1101                self.mouse_dragged(*position, layout, paint, cx)
1102            }
1103            Event::ScrollWheel {
1104                position,
1105                delta,
1106                precise,
1107            } => self.scroll(*position, *delta, *precise, layout, paint, cx),
1108            Event::KeyDown {
1109                chars, keystroke, ..
1110            } => self.key_down(chars, keystroke, cx),
1111            _ => false,
1112        }
1113    }
1114
1115    fn debug(
1116        &self,
1117        bounds: RectF,
1118        _: &Self::LayoutState,
1119        _: &Self::PaintState,
1120        _: &gpui::DebugContext,
1121    ) -> json::Value {
1122        json!({
1123            "type": "BufferElement",
1124            "bounds": bounds.to_json()
1125        })
1126    }
1127}
1128
1129pub struct LayoutState {
1130    size: Vector2F,
1131    scroll_max: Vector2F,
1132    gutter_size: Vector2F,
1133    gutter_padding: f32,
1134    gutter_margin: f32,
1135    text_size: Vector2F,
1136    snapshot: EditorSnapshot,
1137    active_rows: BTreeMap<u32, bool>,
1138    highlighted_rows: Option<Range<u32>>,
1139    line_layouts: Vec<text_layout::Line>,
1140    line_number_layouts: Vec<Option<text_layout::Line>>,
1141    blocks: Vec<(u32, ElementBox)>,
1142    line_height: f32,
1143    em_width: f32,
1144    em_advance: f32,
1145    highlighted_ranges: Vec<(Range<DisplayPoint>, Color)>,
1146    selections: HashMap<ReplicaId, Vec<text::Selection<DisplayPoint>>>,
1147    context_menu: Option<(DisplayPoint, ElementBox)>,
1148    code_actions_indicator: Option<(u32, ElementBox)>,
1149}
1150
1151fn layout_line(
1152    row: u32,
1153    snapshot: &EditorSnapshot,
1154    style: &EditorStyle,
1155    layout_cache: &TextLayoutCache,
1156) -> text_layout::Line {
1157    let mut line = snapshot.line(row);
1158
1159    if line.len() > MAX_LINE_LEN {
1160        let mut len = MAX_LINE_LEN;
1161        while !line.is_char_boundary(len) {
1162            len -= 1;
1163        }
1164        line.truncate(len);
1165    }
1166
1167    layout_cache.layout_str(
1168        &line,
1169        style.text.font_size,
1170        &[(
1171            snapshot.line_len(row) as usize,
1172            RunStyle {
1173                font_id: style.text.font_id,
1174                color: Color::black(),
1175                underline: None,
1176            },
1177        )],
1178    )
1179}
1180
1181pub struct PaintState {
1182    bounds: RectF,
1183    gutter_bounds: RectF,
1184    text_bounds: RectF,
1185}
1186
1187impl PaintState {
1188    fn point_for_position(
1189        &self,
1190        snapshot: &EditorSnapshot,
1191        layout: &LayoutState,
1192        position: Vector2F,
1193    ) -> (DisplayPoint, u32) {
1194        let scroll_position = snapshot.scroll_position();
1195        let position = position - self.text_bounds.origin();
1196        let y = position.y().max(0.0).min(layout.size.y());
1197        let row = ((y / layout.line_height) + scroll_position.y()) as u32;
1198        let row = cmp::min(row, snapshot.max_point().row());
1199        let line = &layout.line_layouts[(row - scroll_position.y() as u32) as usize];
1200        let x = position.x() + (scroll_position.x() * layout.em_width);
1201
1202        let column = if x >= 0.0 {
1203            line.index_for_x(x)
1204                .map(|ix| ix as u32)
1205                .unwrap_or_else(|| snapshot.line_len(row))
1206        } else {
1207            0
1208        };
1209        let overshoot = (0f32.max(x - line.width()) / layout.em_advance) as u32;
1210
1211        (DisplayPoint::new(row, column), overshoot)
1212    }
1213}
1214
1215struct Cursor {
1216    origin: Vector2F,
1217    line_height: f32,
1218    color: Color,
1219}
1220
1221impl Cursor {
1222    fn paint(&self, cx: &mut PaintContext) {
1223        cx.scene.push_quad(Quad {
1224            bounds: RectF::new(self.origin, vec2f(2.0, self.line_height)),
1225            background: Some(self.color),
1226            border: Border::new(0., Color::black()),
1227            corner_radius: 0.,
1228        });
1229    }
1230}
1231
1232#[derive(Debug)]
1233struct HighlightedRange {
1234    start_y: f32,
1235    line_height: f32,
1236    lines: Vec<HighlightedRangeLine>,
1237    color: Color,
1238    corner_radius: f32,
1239}
1240
1241#[derive(Debug)]
1242struct HighlightedRangeLine {
1243    start_x: f32,
1244    end_x: f32,
1245}
1246
1247impl HighlightedRange {
1248    fn paint(&self, bounds: RectF, scene: &mut Scene) {
1249        if self.lines.len() >= 2 && self.lines[0].start_x > self.lines[1].end_x {
1250            self.paint_lines(self.start_y, &self.lines[0..1], bounds, scene);
1251            self.paint_lines(
1252                self.start_y + self.line_height,
1253                &self.lines[1..],
1254                bounds,
1255                scene,
1256            );
1257        } else {
1258            self.paint_lines(self.start_y, &self.lines, bounds, scene);
1259        }
1260    }
1261
1262    fn paint_lines(
1263        &self,
1264        start_y: f32,
1265        lines: &[HighlightedRangeLine],
1266        bounds: RectF,
1267        scene: &mut Scene,
1268    ) {
1269        if lines.is_empty() {
1270            return;
1271        }
1272
1273        let mut path = PathBuilder::new();
1274        let first_line = lines.first().unwrap();
1275        let last_line = lines.last().unwrap();
1276
1277        let first_top_left = vec2f(first_line.start_x, start_y);
1278        let first_top_right = vec2f(first_line.end_x, start_y);
1279
1280        let curve_height = vec2f(0., self.corner_radius);
1281        let curve_width = |start_x: f32, end_x: f32| {
1282            let max = (end_x - start_x) / 2.;
1283            let width = if max < self.corner_radius {
1284                max
1285            } else {
1286                self.corner_radius
1287            };
1288
1289            vec2f(width, 0.)
1290        };
1291
1292        let top_curve_width = curve_width(first_line.start_x, first_line.end_x);
1293        path.reset(first_top_right - top_curve_width);
1294        path.curve_to(first_top_right + curve_height, first_top_right);
1295
1296        let mut iter = lines.iter().enumerate().peekable();
1297        while let Some((ix, line)) = iter.next() {
1298            let bottom_right = vec2f(line.end_x, start_y + (ix + 1) as f32 * self.line_height);
1299
1300            if let Some((_, next_line)) = iter.peek() {
1301                let next_top_right = vec2f(next_line.end_x, bottom_right.y());
1302
1303                match next_top_right.x().partial_cmp(&bottom_right.x()).unwrap() {
1304                    Ordering::Equal => {
1305                        path.line_to(bottom_right);
1306                    }
1307                    Ordering::Less => {
1308                        let curve_width = curve_width(next_top_right.x(), bottom_right.x());
1309                        path.line_to(bottom_right - curve_height);
1310                        if self.corner_radius > 0. {
1311                            path.curve_to(bottom_right - curve_width, bottom_right);
1312                        }
1313                        path.line_to(next_top_right + curve_width);
1314                        if self.corner_radius > 0. {
1315                            path.curve_to(next_top_right + curve_height, next_top_right);
1316                        }
1317                    }
1318                    Ordering::Greater => {
1319                        let curve_width = curve_width(bottom_right.x(), next_top_right.x());
1320                        path.line_to(bottom_right - curve_height);
1321                        if self.corner_radius > 0. {
1322                            path.curve_to(bottom_right + curve_width, bottom_right);
1323                        }
1324                        path.line_to(next_top_right - curve_width);
1325                        if self.corner_radius > 0. {
1326                            path.curve_to(next_top_right + curve_height, next_top_right);
1327                        }
1328                    }
1329                }
1330            } else {
1331                let curve_width = curve_width(line.start_x, line.end_x);
1332                path.line_to(bottom_right - curve_height);
1333                if self.corner_radius > 0. {
1334                    path.curve_to(bottom_right - curve_width, bottom_right);
1335                }
1336
1337                let bottom_left = vec2f(line.start_x, bottom_right.y());
1338                path.line_to(bottom_left + curve_width);
1339                if self.corner_radius > 0. {
1340                    path.curve_to(bottom_left - curve_height, bottom_left);
1341                }
1342            }
1343        }
1344
1345        if first_line.start_x > last_line.start_x {
1346            let curve_width = curve_width(last_line.start_x, first_line.start_x);
1347            let second_top_left = vec2f(last_line.start_x, start_y + self.line_height);
1348            path.line_to(second_top_left + curve_height);
1349            if self.corner_radius > 0. {
1350                path.curve_to(second_top_left + curve_width, second_top_left);
1351            }
1352            let first_bottom_left = vec2f(first_line.start_x, second_top_left.y());
1353            path.line_to(first_bottom_left - curve_width);
1354            if self.corner_radius > 0. {
1355                path.curve_to(first_bottom_left - curve_height, first_bottom_left);
1356            }
1357        }
1358
1359        path.line_to(first_top_left + curve_height);
1360        if self.corner_radius > 0. {
1361            path.curve_to(first_top_left + top_curve_width, first_top_left);
1362        }
1363        path.line_to(first_top_right - top_curve_width);
1364
1365        scene.push_path(path.build(self.color, Some(bounds)));
1366    }
1367}
1368
1369fn scale_vertical_mouse_autoscroll_delta(delta: f32) -> f32 {
1370    delta.powf(1.5) / 100.0
1371}
1372
1373fn scale_horizontal_mouse_autoscroll_delta(delta: f32) -> f32 {
1374    delta.powf(1.2) / 300.0
1375}
1376
1377#[cfg(test)]
1378mod tests {
1379    use super::*;
1380    use crate::{Editor, EditorSettings, MultiBuffer};
1381    use std::sync::Arc;
1382    use util::test::sample_text;
1383
1384    #[gpui::test]
1385    fn test_layout_line_numbers(cx: &mut gpui::MutableAppContext) {
1386        let settings = EditorSettings::test(cx);
1387        let buffer = MultiBuffer::build_simple(&sample_text(6, 6, 'a'), cx);
1388        let (window_id, editor) = cx.add_window(Default::default(), |cx| {
1389            Editor::for_buffer(
1390                buffer,
1391                {
1392                    let settings = settings.clone();
1393                    Arc::new(move |_| settings.clone())
1394                },
1395                None,
1396                cx,
1397            )
1398        });
1399        let element = EditorElement::new(editor.downgrade(), settings);
1400
1401        let layouts = editor.update(cx, |editor, cx| {
1402            let snapshot = editor.snapshot(cx);
1403            let mut presenter = cx.build_presenter(window_id, 30.);
1404            let mut layout_cx = presenter.build_layout_context(false, cx);
1405            element.layout_line_numbers(0..6, &Default::default(), &snapshot, &mut layout_cx)
1406        });
1407        assert_eq!(layouts.len(), 6);
1408    }
1409}