buffer_view.rs

   1use super::{
   2    buffer, movement, Anchor, Bias, Buffer, BufferElement, DisplayMap, DisplayPoint, Point,
   3    Selection, SelectionSetId, ToOffset, ToPoint,
   4};
   5use crate::{settings::Settings, watch, workspace};
   6use anyhow::Result;
   7use futures_core::future::LocalBoxFuture;
   8use gpui::{
   9    fonts::Properties as FontProperties, keymap::Binding, text_layout, AppContext, ClipboardItem,
  10    Element, ElementBox, Entity, FontCache, ModelHandle, MutableAppContext, View, ViewContext,
  11    WeakViewHandle,
  12};
  13use gpui::{geometry::vector::Vector2F, TextLayoutCache};
  14use parking_lot::Mutex;
  15use serde::{Deserialize, Serialize};
  16use smallvec::SmallVec;
  17use smol::Timer;
  18use std::{
  19    cmp::{self, Ordering},
  20    fmt::Write,
  21    iter::FromIterator,
  22    ops::Range,
  23    path::Path,
  24    sync::Arc,
  25    time::Duration,
  26};
  27
  28const CURSOR_BLINK_INTERVAL: Duration = Duration::from_millis(500);
  29
  30pub fn init(app: &mut MutableAppContext) {
  31    app.add_bindings(vec![
  32        Binding::new("backspace", "buffer:backspace", Some("BufferView")),
  33        Binding::new("enter", "buffer:newline", Some("BufferView")),
  34        Binding::new("cmd-x", "buffer:cut", Some("BufferView")),
  35        Binding::new("cmd-c", "buffer:copy", Some("BufferView")),
  36        Binding::new("cmd-v", "buffer:paste", Some("BufferView")),
  37        Binding::new("cmd-z", "buffer:undo", Some("BufferView")),
  38        Binding::new("cmd-shift-Z", "buffer:redo", Some("BufferView")),
  39        Binding::new("up", "buffer:move_up", Some("BufferView")),
  40        Binding::new("down", "buffer:move_down", Some("BufferView")),
  41        Binding::new("left", "buffer:move_left", Some("BufferView")),
  42        Binding::new("right", "buffer:move_right", Some("BufferView")),
  43        Binding::new("shift-up", "buffer:select_up", Some("BufferView")),
  44        Binding::new("shift-down", "buffer:select_down", Some("BufferView")),
  45        Binding::new("shift-left", "buffer:select_left", Some("BufferView")),
  46        Binding::new("shift-right", "buffer:select_right", Some("BufferView")),
  47        Binding::new("cmd-a", "buffer:select_all", Some("BufferView")),
  48        Binding::new("pageup", "buffer:page_up", Some("BufferView")),
  49        Binding::new("pagedown", "buffer:page_down", Some("BufferView")),
  50        Binding::new("alt-cmd-[", "buffer:fold", Some("BufferView")),
  51        Binding::new("alt-cmd-]", "buffer:unfold", Some("BufferView")),
  52        Binding::new(
  53            "alt-cmd-f",
  54            "buffer:fold_selected_ranges",
  55            Some("BufferView"),
  56        ),
  57    ]);
  58
  59    app.add_action("buffer:scroll", BufferView::scroll);
  60    app.add_action("buffer:select", BufferView::select);
  61    app.add_action("buffer:insert", BufferView::insert);
  62    app.add_action("buffer:newline", BufferView::newline);
  63    app.add_action("buffer:backspace", BufferView::backspace);
  64    app.add_action("buffer:cut", BufferView::cut);
  65    app.add_action("buffer:copy", BufferView::copy);
  66    app.add_action("buffer:paste", BufferView::paste);
  67    app.add_action("buffer:undo", BufferView::undo);
  68    app.add_action("buffer:redo", BufferView::redo);
  69    app.add_action("buffer:move_up", BufferView::move_up);
  70    app.add_action("buffer:move_down", BufferView::move_down);
  71    app.add_action("buffer:move_left", BufferView::move_left);
  72    app.add_action("buffer:move_right", BufferView::move_right);
  73    app.add_action("buffer:select_up", BufferView::select_up);
  74    app.add_action("buffer:select_down", BufferView::select_down);
  75    app.add_action("buffer:select_left", BufferView::select_left);
  76    app.add_action("buffer:select_right", BufferView::select_right);
  77    app.add_action("buffer:select_all", BufferView::select_all);
  78    app.add_action("buffer:page_up", BufferView::page_up);
  79    app.add_action("buffer:page_down", BufferView::page_down);
  80    app.add_action("buffer:fold", BufferView::fold);
  81    app.add_action("buffer:unfold", BufferView::unfold);
  82    app.add_action(
  83        "buffer:fold_selected_ranges",
  84        BufferView::fold_selected_ranges,
  85    );
  86}
  87
  88pub enum SelectAction {
  89    Begin {
  90        position: DisplayPoint,
  91        add: bool,
  92    },
  93    Update {
  94        position: DisplayPoint,
  95        scroll_position: Vector2F,
  96    },
  97    End,
  98}
  99
 100pub struct BufferView {
 101    handle: WeakViewHandle<Self>,
 102    buffer: ModelHandle<Buffer>,
 103    display_map: ModelHandle<DisplayMap>,
 104    selection_set_id: SelectionSetId,
 105    pending_selection: Option<Selection>,
 106    scroll_position: Mutex<Vector2F>,
 107    autoscroll_requested: Mutex<bool>,
 108    settings: watch::Receiver<Settings>,
 109    focused: bool,
 110    cursors_visible: bool,
 111    blink_epoch: usize,
 112    blinking_paused: bool,
 113    single_line: bool,
 114}
 115
 116#[derive(Serialize, Deserialize)]
 117struct ClipboardSelection {
 118    len: usize,
 119    is_entire_line: bool,
 120}
 121
 122impl BufferView {
 123    pub fn single_line(settings: watch::Receiver<Settings>, ctx: &mut ViewContext<Self>) -> Self {
 124        let buffer = ctx.add_model(|ctx| Buffer::new(0, String::new(), ctx));
 125        let mut view = Self::for_buffer(buffer, settings, ctx);
 126        view.single_line = true;
 127        view
 128    }
 129
 130    pub fn for_buffer(
 131        buffer: ModelHandle<Buffer>,
 132        settings: watch::Receiver<Settings>,
 133        ctx: &mut ViewContext<Self>,
 134    ) -> Self {
 135        settings.notify_view_on_change(ctx);
 136
 137        ctx.observe(&buffer, Self::on_buffer_changed);
 138        ctx.subscribe_to_model(&buffer, Self::on_buffer_event);
 139        let display_map = ctx.add_model(|ctx| {
 140            DisplayMap::new(
 141                buffer.clone(),
 142                smol::block_on(settings.read()).tab_size,
 143                ctx,
 144            )
 145        });
 146        ctx.observe(&display_map, Self::on_display_map_changed);
 147
 148        let (selection_set_id, _) = buffer.update(ctx, |buffer, ctx| {
 149            buffer.add_selection_set(
 150                vec![Selection {
 151                    start: buffer.anchor_before(0).unwrap(),
 152                    end: buffer.anchor_before(0).unwrap(),
 153                    reversed: false,
 154                    goal_column: None,
 155                }],
 156                Some(ctx),
 157            )
 158        });
 159        Self {
 160            handle: ctx.handle().downgrade(),
 161            buffer,
 162            display_map,
 163            selection_set_id,
 164            pending_selection: None,
 165            scroll_position: Mutex::new(Vector2F::zero()),
 166            autoscroll_requested: Mutex::new(false),
 167            settings,
 168            focused: false,
 169            cursors_visible: false,
 170            blink_epoch: 0,
 171            blinking_paused: false,
 172            single_line: false,
 173        }
 174    }
 175
 176    pub fn buffer(&self) -> &ModelHandle<Buffer> {
 177        &self.buffer
 178    }
 179
 180    pub fn is_gutter_visible(&self) -> bool {
 181        !self.single_line
 182    }
 183
 184    fn scroll(&mut self, scroll_position: &Vector2F, ctx: &mut ViewContext<Self>) {
 185        *self.scroll_position.lock() = *scroll_position;
 186        ctx.notify();
 187    }
 188
 189    pub fn scroll_position(&self) -> Vector2F {
 190        *self.scroll_position.lock()
 191    }
 192
 193    pub fn clamp_scroll_left(&self, max: f32) {
 194        let mut scroll_position = self.scroll_position.lock();
 195        let scroll_left = scroll_position.x();
 196        scroll_position.set_x(scroll_left.min(max));
 197    }
 198
 199    pub fn autoscroll_vertically(
 200        &self,
 201        viewport_height: f32,
 202        line_height: f32,
 203        app: &AppContext,
 204    ) -> bool {
 205        let mut scroll_position = self.scroll_position.lock();
 206        let scroll_top = scroll_position.y();
 207        scroll_position.set_y(scroll_top.min(self.max_point(app).row().saturating_sub(1) as f32));
 208
 209        let mut autoscroll_requested = self.autoscroll_requested.lock();
 210        if *autoscroll_requested {
 211            *autoscroll_requested = false;
 212        } else {
 213            return false;
 214        }
 215
 216        let map = self.display_map.read(app);
 217        let visible_lines = viewport_height / line_height;
 218        let first_cursor_top = self
 219            .selections(app)
 220            .first()
 221            .unwrap()
 222            .head()
 223            .to_display_point(map, app)
 224            .unwrap()
 225            .row() as f32;
 226        let last_cursor_bottom = self
 227            .selections(app)
 228            .last()
 229            .unwrap()
 230            .head()
 231            .to_display_point(map, app)
 232            .unwrap()
 233            .row() as f32
 234            + 1.0;
 235
 236        let margin = ((visible_lines - (last_cursor_bottom - first_cursor_top)) / 2.0)
 237            .floor()
 238            .min(3.0);
 239        if margin < 0.0 {
 240            return false;
 241        }
 242
 243        let target_top = (first_cursor_top - margin).max(0.0);
 244        let target_bottom = last_cursor_bottom + margin;
 245        let start_row = scroll_position.y();
 246        let end_row = start_row + visible_lines;
 247
 248        if target_top < start_row {
 249            scroll_position.set_y(target_top);
 250        } else if target_bottom >= end_row {
 251            scroll_position.set_y(target_bottom - visible_lines);
 252        }
 253
 254        true
 255    }
 256
 257    pub fn autoscroll_horizontally(
 258        &self,
 259        start_row: u32,
 260        viewport_width: f32,
 261        scroll_width: f32,
 262        max_glyph_width: f32,
 263        layouts: &[Arc<text_layout::Line>],
 264        app: &AppContext,
 265    ) {
 266        let map = self.display_map.read(app);
 267
 268        let mut target_left = std::f32::INFINITY;
 269        let mut target_right = 0.0_f32;
 270        for selection in self.selections(app) {
 271            let head = selection.head().to_display_point(map, app).unwrap();
 272            let start_column = head.column().saturating_sub(3);
 273            let end_column = cmp::min(map.line_len(head.row(), app).unwrap(), head.column() + 3);
 274            target_left = target_left
 275                .min(layouts[(head.row() - start_row) as usize].x_for_index(start_column as usize));
 276            target_right = target_right.max(
 277                layouts[(head.row() - start_row) as usize].x_for_index(end_column as usize)
 278                    + max_glyph_width,
 279            );
 280        }
 281        target_right = target_right.min(scroll_width);
 282
 283        if target_right - target_left > viewport_width {
 284            return;
 285        }
 286
 287        let mut scroll_position = self.scroll_position.lock();
 288        let scroll_left = scroll_position.x() * max_glyph_width;
 289        let scroll_right = scroll_left + viewport_width;
 290
 291        if target_left < scroll_left {
 292            scroll_position.set_x(target_left / max_glyph_width);
 293        } else if target_right > scroll_right {
 294            scroll_position.set_x((target_right - viewport_width) / max_glyph_width);
 295        }
 296    }
 297
 298    fn select(&mut self, arg: &SelectAction, ctx: &mut ViewContext<Self>) {
 299        match arg {
 300            SelectAction::Begin { position, add } => self.begin_selection(*position, *add, ctx),
 301            SelectAction::Update {
 302                position,
 303                scroll_position,
 304            } => self.update_selection(*position, *scroll_position, ctx),
 305            SelectAction::End => self.end_selection(ctx),
 306        }
 307    }
 308
 309    fn begin_selection(&mut self, position: DisplayPoint, add: bool, ctx: &mut ViewContext<Self>) {
 310        if !self.focused {
 311            ctx.focus_self();
 312            ctx.emit(Event::Activate);
 313        }
 314
 315        let display_map = self.display_map.read(ctx);
 316        let cursor = display_map
 317            .anchor_before(position, Bias::Left, ctx.as_ref())
 318            .unwrap();
 319        let selection = Selection {
 320            start: cursor.clone(),
 321            end: cursor,
 322            reversed: false,
 323            goal_column: None,
 324        };
 325
 326        if !add {
 327            self.update_selections(Vec::new(), false, ctx);
 328        }
 329        self.pending_selection = Some(selection);
 330
 331        ctx.notify();
 332    }
 333
 334    fn update_selection(
 335        &mut self,
 336        position: DisplayPoint,
 337        scroll_position: Vector2F,
 338        ctx: &mut ViewContext<Self>,
 339    ) {
 340        let buffer = self.buffer.read(ctx);
 341        let map = self.display_map.read(ctx);
 342        let cursor = map
 343            .anchor_before(position, Bias::Left, ctx.as_ref())
 344            .unwrap();
 345        if let Some(selection) = self.pending_selection.as_mut() {
 346            selection.set_head(buffer, cursor);
 347        } else {
 348            log::error!("update_selection dispatched with no pending selection");
 349            return;
 350        }
 351
 352        *self.scroll_position.lock() = scroll_position;
 353
 354        ctx.notify();
 355    }
 356
 357    fn end_selection(&mut self, ctx: &mut ViewContext<Self>) {
 358        if let Some(selection) = self.pending_selection.take() {
 359            let ix = self.selection_insertion_index(&selection.start, ctx.as_ref());
 360            let mut selections = self.selections(ctx.as_ref()).to_vec();
 361            selections.insert(ix, selection);
 362            self.update_selections(selections, false, ctx);
 363        } else {
 364            log::error!("end_selection dispatched with no pending selection");
 365        }
 366    }
 367
 368    pub fn is_selecting(&self) -> bool {
 369        self.pending_selection.is_some()
 370    }
 371
 372    #[cfg(test)]
 373    fn select_ranges<'a, T>(&mut self, ranges: T, ctx: &mut ViewContext<Self>) -> Result<()>
 374    where
 375        T: IntoIterator<Item = &'a Range<usize>>,
 376    {
 377        let buffer = self.buffer.read(ctx);
 378        let mut selections = Vec::new();
 379        for range in ranges {
 380            selections.push(Selection {
 381                start: buffer.anchor_before(range.start)?,
 382                end: buffer.anchor_before(range.end)?,
 383                reversed: false,
 384                goal_column: None,
 385            });
 386        }
 387        self.update_selections(selections, false, ctx);
 388        Ok(())
 389    }
 390
 391    #[cfg(test)]
 392    fn select_display_ranges<'a, T>(&mut self, ranges: T, ctx: &mut ViewContext<Self>) -> Result<()>
 393    where
 394        T: IntoIterator<Item = &'a Range<DisplayPoint>>,
 395    {
 396        let map = self.display_map.read(ctx);
 397        let mut selections = Vec::new();
 398        for range in ranges {
 399            selections.push(Selection {
 400                start: map.anchor_before(range.start, Bias::Left, ctx.as_ref())?,
 401                end: map.anchor_before(range.end, Bias::Left, ctx.as_ref())?,
 402                reversed: false,
 403                goal_column: None,
 404            });
 405        }
 406        self.update_selections(selections, false, ctx);
 407        Ok(())
 408    }
 409
 410    fn insert(&mut self, text: &String, ctx: &mut ViewContext<Self>) {
 411        let mut offset_ranges = SmallVec::<[Range<usize>; 32]>::new();
 412        {
 413            let buffer = self.buffer.read(ctx);
 414            for selection in self.selections(ctx.as_ref()) {
 415                let start = selection.start.to_offset(buffer).unwrap();
 416                let end = selection.end.to_offset(buffer).unwrap();
 417                offset_ranges.push(start..end);
 418            }
 419        }
 420
 421        self.start_transaction(ctx);
 422        let mut new_selections = Vec::new();
 423        self.buffer.update(ctx, |buffer, ctx| {
 424            if let Err(error) = buffer.edit(offset_ranges.iter().cloned(), text.as_str(), Some(ctx))
 425            {
 426                log::error!("error inserting text: {}", error);
 427            };
 428            let char_count = text.chars().count() as isize;
 429            let mut delta = 0_isize;
 430            new_selections = offset_ranges
 431                .into_iter()
 432                .map(|range| {
 433                    let start = range.start as isize;
 434                    let end = range.end as isize;
 435                    let anchor = buffer
 436                        .anchor_before((start + delta + char_count) as usize)
 437                        .unwrap();
 438                    let deleted_count = end - start;
 439                    delta += char_count - deleted_count;
 440                    Selection {
 441                        start: anchor.clone(),
 442                        end: anchor,
 443                        reversed: false,
 444                        goal_column: None,
 445                    }
 446                })
 447                .collect();
 448        });
 449
 450        self.update_selections(new_selections, true, ctx);
 451        self.end_transaction(ctx);
 452    }
 453
 454    fn newline(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 455        if self.single_line {
 456            ctx.propagate_action();
 457        } else {
 458            self.insert(&"\n".into(), ctx);
 459        }
 460    }
 461
 462    pub fn backspace(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 463        self.start_transaction(ctx);
 464        let mut selections = self.selections(ctx.as_ref()).to_vec();
 465        {
 466            let buffer = self.buffer.read(ctx);
 467            let map = self.display_map.read(ctx);
 468            for selection in &mut selections {
 469                if selection.range(buffer).is_empty() {
 470                    let head = selection
 471                        .head()
 472                        .to_display_point(map, ctx.as_ref())
 473                        .unwrap();
 474                    let cursor = map
 475                        .anchor_before(
 476                            movement::left(map, head, ctx.as_ref()).unwrap(),
 477                            Bias::Left,
 478                            ctx.as_ref(),
 479                        )
 480                        .unwrap();
 481                    selection.set_head(&buffer, cursor);
 482                    selection.goal_column = None;
 483                }
 484            }
 485        }
 486
 487        self.update_selections(selections, true, ctx);
 488        self.insert(&String::new(), ctx);
 489        self.end_transaction(ctx);
 490    }
 491
 492    pub fn cut(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 493        self.start_transaction(ctx);
 494        let mut text = String::new();
 495        let mut selections = self.selections(ctx.as_ref()).to_vec();
 496        let mut clipboard_selections = Vec::with_capacity(selections.len());
 497        {
 498            let buffer = self.buffer.read(ctx);
 499            let max_point = buffer.max_point();
 500            for selection in &mut selections {
 501                let mut start = selection.start.to_point(buffer).expect("invalid start");
 502                let mut end = selection.end.to_point(buffer).expect("invalid end");
 503                let is_entire_line = start == end;
 504                if is_entire_line {
 505                    start = Point::new(start.row, 0);
 506                    end = cmp::min(max_point, Point::new(start.row + 1, 0));
 507                    selection.start = buffer.anchor_before(start).unwrap();
 508                    selection.end = buffer.anchor_before(end).unwrap();
 509                }
 510                let mut len = 0;
 511                for ch in buffer.text_for_range(start..end).unwrap() {
 512                    text.push(ch);
 513                    len += 1;
 514                }
 515                clipboard_selections.push(ClipboardSelection {
 516                    len,
 517                    is_entire_line,
 518                });
 519            }
 520        }
 521        self.update_selections(selections, true, ctx);
 522        self.insert(&String::new(), ctx);
 523        self.end_transaction(ctx);
 524
 525        ctx.as_mut()
 526            .write_to_clipboard(ClipboardItem::new(text).with_metadata(clipboard_selections));
 527    }
 528
 529    pub fn copy(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 530        let buffer = self.buffer.read(ctx);
 531        let max_point = buffer.max_point();
 532        let mut text = String::new();
 533        let selections = self.selections(ctx.as_ref());
 534        let mut clipboard_selections = Vec::with_capacity(selections.len());
 535        for selection in selections {
 536            let mut start = selection.start.to_point(buffer).expect("invalid start");
 537            let mut end = selection.end.to_point(buffer).expect("invalid end");
 538            let is_entire_line = start == end;
 539            if is_entire_line {
 540                start = Point::new(start.row, 0);
 541                end = cmp::min(max_point, Point::new(start.row + 1, 0));
 542            }
 543            let mut len = 0;
 544            for ch in buffer.text_for_range(start..end).unwrap() {
 545                text.push(ch);
 546                len += 1;
 547            }
 548            clipboard_selections.push(ClipboardSelection {
 549                len,
 550                is_entire_line,
 551            });
 552        }
 553
 554        ctx.as_mut()
 555            .write_to_clipboard(ClipboardItem::new(text).with_metadata(clipboard_selections));
 556    }
 557
 558    pub fn paste(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 559        if let Some(item) = ctx.as_mut().read_from_clipboard() {
 560            let clipboard_text = item.text();
 561            if let Some(mut clipboard_selections) = item.metadata::<Vec<ClipboardSelection>>() {
 562                let selections = self.selections(ctx.as_ref()).to_vec();
 563                if clipboard_selections.len() != selections.len() {
 564                    let merged_selection = ClipboardSelection {
 565                        len: clipboard_selections.iter().map(|s| s.len).sum(),
 566                        is_entire_line: clipboard_selections.iter().all(|s| s.is_entire_line),
 567                    };
 568                    clipboard_selections.clear();
 569                    clipboard_selections.push(merged_selection);
 570                }
 571
 572                self.start_transaction(ctx);
 573                let mut new_selections = Vec::with_capacity(selections.len());
 574                let mut clipboard_chars = clipboard_text.chars().cycle();
 575                for (selection, clipboard_selection) in
 576                    selections.iter().zip(clipboard_selections.iter().cycle())
 577                {
 578                    let to_insert =
 579                        String::from_iter(clipboard_chars.by_ref().take(clipboard_selection.len));
 580
 581                    self.buffer.update(ctx, |buffer, ctx| {
 582                        let selection_start = selection.start.to_point(buffer).unwrap();
 583                        let selection_end = selection.end.to_point(buffer).unwrap();
 584
 585                        // If the corresponding selection was empty when this slice of the
 586                        // clipboard text was written, then the entire line containing the
 587                        // selection was copied. If this selection is also currently empty,
 588                        // then paste the line before the current line of the buffer.
 589                        let new_selection_start = selection.end.bias_right(buffer).unwrap();
 590                        if selection_start == selection_end && clipboard_selection.is_entire_line {
 591                            let line_start = Point::new(selection_start.row, 0);
 592                            buffer
 593                                .edit(Some(line_start..line_start), to_insert, Some(ctx))
 594                                .unwrap();
 595                        } else {
 596                            buffer
 597                                .edit(Some(&selection.start..&selection.end), to_insert, Some(ctx))
 598                                .unwrap();
 599                        };
 600
 601                        let new_selection_start = new_selection_start.bias_left(buffer).unwrap();
 602                        new_selections.push(Selection {
 603                            start: new_selection_start.clone(),
 604                            end: new_selection_start,
 605                            reversed: false,
 606                            goal_column: None,
 607                        });
 608                    });
 609                }
 610                self.update_selections(new_selections, true, ctx);
 611                self.end_transaction(ctx);
 612            } else {
 613                self.insert(clipboard_text, ctx);
 614            }
 615        }
 616    }
 617
 618    pub fn undo(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 619        self.buffer
 620            .update(ctx, |buffer, ctx| buffer.undo(Some(ctx)));
 621    }
 622
 623    pub fn redo(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 624        self.buffer
 625            .update(ctx, |buffer, ctx| buffer.redo(Some(ctx)));
 626    }
 627
 628    pub fn move_left(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 629        let app = ctx.as_ref();
 630        let mut selections = self.selections(app).to_vec();
 631        {
 632            let map = self.display_map.read(app);
 633            for selection in &mut selections {
 634                let start = selection.start.to_display_point(map, app).unwrap();
 635                let end = selection.end.to_display_point(map, app).unwrap();
 636
 637                if start != end {
 638                    selection.end = selection.start.clone();
 639                } else {
 640                    let cursor = map
 641                        .anchor_before(movement::left(map, start, app).unwrap(), Bias::Left, app)
 642                        .unwrap();
 643                    selection.start = cursor.clone();
 644                    selection.end = cursor;
 645                }
 646                selection.reversed = false;
 647                selection.goal_column = None;
 648            }
 649        }
 650        self.update_selections(selections, true, ctx);
 651    }
 652
 653    pub fn select_left(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 654        let mut selections = self.selections(ctx.as_ref()).to_vec();
 655        {
 656            let buffer = self.buffer.read(ctx);
 657            let map = self.display_map.read(ctx);
 658            for selection in &mut selections {
 659                let head = selection
 660                    .head()
 661                    .to_display_point(map, ctx.as_ref())
 662                    .unwrap();
 663                let cursor = map
 664                    .anchor_before(
 665                        movement::left(map, head, ctx.as_ref()).unwrap(),
 666                        Bias::Left,
 667                        ctx.as_ref(),
 668                    )
 669                    .unwrap();
 670                selection.set_head(&buffer, cursor);
 671                selection.goal_column = None;
 672            }
 673        }
 674        self.update_selections(selections, true, ctx);
 675    }
 676
 677    pub fn move_right(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 678        let mut selections = self.selections(ctx.as_ref()).to_vec();
 679        {
 680            let app = ctx.as_ref();
 681            let map = self.display_map.read(app);
 682            for selection in &mut selections {
 683                let start = selection.start.to_display_point(map, app).unwrap();
 684                let end = selection.end.to_display_point(map, app).unwrap();
 685
 686                if start != end {
 687                    selection.start = selection.end.clone();
 688                } else {
 689                    let cursor = map
 690                        .anchor_before(movement::right(map, end, app).unwrap(), Bias::Right, app)
 691                        .unwrap();
 692                    selection.start = cursor.clone();
 693                    selection.end = cursor;
 694                }
 695                selection.reversed = false;
 696                selection.goal_column = None;
 697            }
 698        }
 699        self.update_selections(selections, true, ctx);
 700    }
 701
 702    pub fn select_right(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 703        let mut selections = self.selections(ctx.as_ref()).to_vec();
 704        {
 705            let app = ctx.as_ref();
 706            let buffer = self.buffer.read(app);
 707            let map = self.display_map.read(app);
 708            for selection in &mut selections {
 709                let head = selection
 710                    .head()
 711                    .to_display_point(map, ctx.as_ref())
 712                    .unwrap();
 713                let cursor = map
 714                    .anchor_before(movement::right(map, head, app).unwrap(), Bias::Right, app)
 715                    .unwrap();
 716                selection.set_head(&buffer, cursor);
 717                selection.goal_column = None;
 718            }
 719        }
 720        self.update_selections(selections, true, ctx);
 721    }
 722
 723    pub fn move_up(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 724        if self.single_line {
 725            ctx.propagate_action();
 726        } else {
 727            let mut selections = self.selections(ctx.as_ref()).to_vec();
 728            {
 729                let app = ctx.as_ref();
 730                let map = self.display_map.read(app);
 731                for selection in &mut selections {
 732                    let start = selection.start.to_display_point(map, app).unwrap();
 733                    let end = selection.end.to_display_point(map, app).unwrap();
 734                    if start != end {
 735                        selection.goal_column = None;
 736                    }
 737
 738                    let (start, goal_column) =
 739                        movement::up(map, start, selection.goal_column, app).unwrap();
 740                    let cursor = map.anchor_before(start, Bias::Left, app).unwrap();
 741                    selection.start = cursor.clone();
 742                    selection.end = cursor;
 743                    selection.goal_column = goal_column;
 744                    selection.reversed = false;
 745                }
 746            }
 747            self.update_selections(selections, true, ctx);
 748        }
 749    }
 750
 751    pub fn select_up(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 752        if self.single_line {
 753            ctx.propagate_action();
 754        } else {
 755            let mut selections = self.selections(ctx.as_ref()).to_vec();
 756            {
 757                let app = ctx.as_ref();
 758                let buffer = self.buffer.read(app);
 759                let map = self.display_map.read(app);
 760                for selection in &mut selections {
 761                    let head = selection.head().to_display_point(map, app).unwrap();
 762                    let (head, goal_column) =
 763                        movement::up(map, head, selection.goal_column, app).unwrap();
 764                    selection.set_head(&buffer, map.anchor_before(head, Bias::Left, app).unwrap());
 765                    selection.goal_column = goal_column;
 766                }
 767            }
 768            self.update_selections(selections, true, ctx);
 769        }
 770    }
 771
 772    pub fn move_down(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 773        if self.single_line {
 774            ctx.propagate_action();
 775        } else {
 776            let mut selections = self.selections(ctx.as_ref()).to_vec();
 777            {
 778                let app = ctx.as_ref();
 779                let map = self.display_map.read(app);
 780                for selection in &mut selections {
 781                    let start = selection.start.to_display_point(map, app).unwrap();
 782                    let end = selection.end.to_display_point(map, app).unwrap();
 783                    if start != end {
 784                        selection.goal_column = None;
 785                    }
 786
 787                    let (start, goal_column) =
 788                        movement::down(map, end, selection.goal_column, app).unwrap();
 789                    let cursor = map.anchor_before(start, Bias::Right, app).unwrap();
 790                    selection.start = cursor.clone();
 791                    selection.end = cursor;
 792                    selection.goal_column = goal_column;
 793                    selection.reversed = false;
 794                }
 795            }
 796            self.update_selections(selections, true, ctx);
 797        }
 798    }
 799
 800    pub fn select_down(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 801        if self.single_line {
 802            ctx.propagate_action();
 803        } else {
 804            let mut selections = self.selections(ctx.as_ref()).to_vec();
 805            {
 806                let app = ctx.as_ref();
 807                let buffer = self.buffer.read(app);
 808                let map = self.display_map.read(app);
 809                for selection in &mut selections {
 810                    let head = selection.head().to_display_point(map, app).unwrap();
 811                    let (head, goal_column) =
 812                        movement::down(map, head, selection.goal_column, app).unwrap();
 813                    selection.set_head(&buffer, map.anchor_before(head, Bias::Right, app).unwrap());
 814                    selection.goal_column = goal_column;
 815                }
 816            }
 817            self.update_selections(selections, true, ctx);
 818        }
 819    }
 820
 821    pub fn select_all(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 822        let selection = Selection {
 823            start: Anchor::Start,
 824            end: Anchor::End,
 825            reversed: false,
 826            goal_column: None,
 827        };
 828        self.update_selections(vec![selection], false, ctx);
 829    }
 830
 831    pub fn selections_in_range<'a>(
 832        &'a self,
 833        range: Range<DisplayPoint>,
 834        app: &'a AppContext,
 835    ) -> impl 'a + Iterator<Item = Range<DisplayPoint>> {
 836        let map = self.display_map.read(app);
 837
 838        let start = map.anchor_before(range.start, Bias::Left, app).unwrap();
 839        let start_index = self.selection_insertion_index(&start, app);
 840        let pending_selection = self.pending_selection.as_ref().and_then(|s| {
 841            let selection_range = s.display_range(map, app);
 842            if selection_range.start <= range.end || selection_range.end <= range.end {
 843                Some(selection_range)
 844            } else {
 845                None
 846            }
 847        });
 848        self.selections(app)[start_index..]
 849            .iter()
 850            .map(move |s| s.display_range(map, app))
 851            .take_while(move |r| r.start <= range.end || r.end <= range.end)
 852            .chain(pending_selection)
 853    }
 854
 855    fn selection_insertion_index(&self, start: &Anchor, app: &AppContext) -> usize {
 856        let buffer = self.buffer.read(app);
 857        let selections = self.selections(app);
 858        match selections.binary_search_by(|probe| probe.start.cmp(&start, buffer).unwrap()) {
 859            Ok(index) => index,
 860            Err(index) => {
 861                if index > 0
 862                    && selections[index - 1].end.cmp(&start, buffer).unwrap() == Ordering::Greater
 863                {
 864                    index - 1
 865                } else {
 866                    index
 867                }
 868            }
 869        }
 870    }
 871
 872    fn selections<'a>(&self, app: &'a AppContext) -> &'a [Selection] {
 873        self.buffer
 874            .read(app)
 875            .selections(self.selection_set_id)
 876            .unwrap()
 877    }
 878
 879    fn update_selections(
 880        &mut self,
 881        mut selections: Vec<Selection>,
 882        autoscroll: bool,
 883        ctx: &mut ViewContext<Self>,
 884    ) {
 885        // Merge overlapping selections.
 886        let buffer = self.buffer.read(ctx);
 887        let mut i = 1;
 888        while i < selections.len() {
 889            if selections[i - 1]
 890                .end
 891                .cmp(&selections[i].start, buffer)
 892                .unwrap()
 893                >= Ordering::Equal
 894            {
 895                let removed = selections.remove(i);
 896                if removed.start.cmp(&selections[i - 1].start, buffer).unwrap() < Ordering::Equal {
 897                    selections[i - 1].start = removed.start;
 898                }
 899                if removed.end.cmp(&selections[i - 1].end, buffer).unwrap() > Ordering::Equal {
 900                    selections[i - 1].end = removed.end;
 901                }
 902            } else {
 903                i += 1;
 904            }
 905        }
 906
 907        self.buffer.update(ctx, |buffer, ctx| {
 908            buffer
 909                .update_selection_set(self.selection_set_id, selections, Some(ctx))
 910                .unwrap()
 911        });
 912        self.pause_cursor_blinking(ctx);
 913
 914        if autoscroll {
 915            *self.autoscroll_requested.lock() = true;
 916            ctx.notify();
 917        }
 918    }
 919
 920    fn start_transaction(&self, ctx: &mut ViewContext<Self>) {
 921        self.buffer.update(ctx, |buffer, _| {
 922            buffer
 923                .start_transaction(Some(self.selection_set_id))
 924                .unwrap()
 925        });
 926    }
 927
 928    fn end_transaction(&self, ctx: &mut ViewContext<Self>) {
 929        self.buffer.update(ctx, |buffer, ctx| {
 930            buffer
 931                .end_transaction(Some(self.selection_set_id), Some(ctx))
 932                .unwrap()
 933        });
 934    }
 935
 936    pub fn page_up(&mut self, _: &(), _: &mut ViewContext<Self>) {
 937        log::info!("BufferView::page_up");
 938    }
 939
 940    pub fn page_down(&mut self, _: &(), _: &mut ViewContext<Self>) {
 941        log::info!("BufferView::page_down");
 942    }
 943
 944    pub fn fold(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 945        use super::RangeExt;
 946
 947        let mut fold_ranges = Vec::new();
 948
 949        let app = ctx.as_ref();
 950        let map = self.display_map.read(app);
 951        for selection in self.selections(app) {
 952            let (start, end) = selection.display_range(map, app).sorted();
 953            let buffer_start_row = start.to_buffer_point(map, Bias::Left, app).unwrap().row;
 954
 955            for row in (0..=end.row()).rev() {
 956                if self.is_line_foldable(row, app) && !map.is_line_folded(row) {
 957                    let fold_range = self.foldable_range_for_line(row, app).unwrap();
 958                    if fold_range.end.row >= buffer_start_row {
 959                        fold_ranges.push(fold_range);
 960                        if row <= start.row() {
 961                            break;
 962                        }
 963                    }
 964                }
 965            }
 966        }
 967
 968        if !fold_ranges.is_empty() {
 969            self.display_map.update(ctx, |map, ctx| {
 970                map.fold(fold_ranges, ctx).unwrap();
 971            });
 972            *self.autoscroll_requested.lock() = true;
 973        }
 974    }
 975
 976    pub fn unfold(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
 977        use super::RangeExt;
 978
 979        let app = ctx.as_ref();
 980        let map = self.display_map.read(app);
 981        let buffer = self.buffer.read(app);
 982        let ranges = self
 983            .selections(app)
 984            .iter()
 985            .map(|s| {
 986                let (start, end) = s.display_range(map, app).sorted();
 987                let mut start = start.to_buffer_point(map, Bias::Left, app).unwrap();
 988                let mut end = end.to_buffer_point(map, Bias::Left, app).unwrap();
 989                start.column = 0;
 990                end.column = buffer.line_len(end.row).unwrap();
 991                start..end
 992            })
 993            .collect::<Vec<_>>();
 994
 995        self.display_map.update(ctx, |map, ctx| {
 996            map.unfold(ranges, ctx).unwrap();
 997        });
 998        *self.autoscroll_requested.lock() = true;
 999    }
1000
1001    fn is_line_foldable(&self, display_row: u32, app: &AppContext) -> bool {
1002        let max_point = self.max_point(app);
1003        if display_row >= max_point.row() {
1004            false
1005        } else {
1006            let (start_indent, is_blank) = self.line_indent(display_row, app).unwrap();
1007            if is_blank {
1008                false
1009            } else {
1010                for display_row in display_row + 1..=max_point.row() {
1011                    let (indent, is_blank) = self.line_indent(display_row, app).unwrap();
1012                    if !is_blank {
1013                        return indent > start_indent;
1014                    }
1015                }
1016                false
1017            }
1018        }
1019    }
1020
1021    fn line_indent(&self, display_row: u32, app: &AppContext) -> Result<(usize, bool)> {
1022        let mut indent = 0;
1023        let mut is_blank = true;
1024        for c in self
1025            .display_map
1026            .read(app)
1027            .chars_at(DisplayPoint::new(display_row, 0), app)?
1028        {
1029            if c == ' ' {
1030                indent += 1;
1031            } else {
1032                is_blank = c == '\n';
1033                break;
1034            }
1035        }
1036        Ok((indent, is_blank))
1037    }
1038
1039    fn foldable_range_for_line(&self, start_row: u32, app: &AppContext) -> Result<Range<Point>> {
1040        let map = self.display_map.read(app);
1041        let max_point = self.max_point(app);
1042
1043        let (start_indent, _) = self.line_indent(start_row, app)?;
1044        let start = DisplayPoint::new(start_row, self.line_len(start_row, app)?);
1045        let mut end = None;
1046        for row in start_row + 1..=max_point.row() {
1047            let (indent, is_blank) = self.line_indent(row, app)?;
1048            if !is_blank && indent <= start_indent {
1049                end = Some(DisplayPoint::new(row - 1, self.line_len(row - 1, app)?));
1050                break;
1051            }
1052        }
1053
1054        let end = end.unwrap_or(max_point);
1055        return Ok(start.to_buffer_point(map, Bias::Left, app)?
1056            ..end.to_buffer_point(map, Bias::Left, app)?);
1057    }
1058
1059    pub fn fold_selected_ranges(&mut self, _: &(), ctx: &mut ViewContext<Self>) {
1060        self.display_map.update(ctx, |map, ctx| {
1061            let buffer = self.buffer.read(ctx);
1062            let ranges = self
1063                .selections(ctx.as_ref())
1064                .iter()
1065                .map(|s| s.range(buffer))
1066                .collect::<Vec<_>>();
1067            map.fold(ranges, ctx).unwrap();
1068        });
1069    }
1070
1071    pub fn line(&self, display_row: u32, app: &AppContext) -> Result<String> {
1072        self.display_map.read(app).line(display_row, app)
1073    }
1074
1075    pub fn line_len(&self, display_row: u32, app: &AppContext) -> Result<u32> {
1076        self.display_map.read(app).line_len(display_row, app)
1077    }
1078
1079    pub fn rightmost_point(&self, app: &AppContext) -> DisplayPoint {
1080        self.display_map.read(app).rightmost_point()
1081    }
1082
1083    pub fn max_point(&self, app: &AppContext) -> DisplayPoint {
1084        self.display_map.read(app).max_point(app)
1085    }
1086
1087    pub fn text(&self, app: &AppContext) -> String {
1088        self.display_map.read(app).text(app)
1089    }
1090
1091    pub fn font_size(&self) -> f32 {
1092        smol::block_on(self.settings.read()).buffer_font_size
1093    }
1094
1095    pub fn font_ascent(&self, font_cache: &FontCache) -> f32 {
1096        let settings = smol::block_on(self.settings.read());
1097        let font_id = font_cache.default_font(settings.buffer_font_family);
1098        let ascent = font_cache.metric(font_id, |m| m.ascent);
1099        font_cache.scale_metric(ascent, font_id, settings.buffer_font_size)
1100    }
1101
1102    pub fn font_descent(&self, font_cache: &FontCache) -> f32 {
1103        let settings = smol::block_on(self.settings.read());
1104        let font_id = font_cache.default_font(settings.buffer_font_family);
1105        let ascent = font_cache.metric(font_id, |m| m.descent);
1106        font_cache.scale_metric(ascent, font_id, settings.buffer_font_size)
1107    }
1108
1109    pub fn line_height(&self, font_cache: &FontCache) -> f32 {
1110        let settings = smol::block_on(self.settings.read());
1111        let font_id = font_cache.default_font(settings.buffer_font_family);
1112        font_cache.line_height(font_id, settings.buffer_font_size)
1113    }
1114
1115    pub fn em_width(&self, font_cache: &FontCache) -> f32 {
1116        let settings = smol::block_on(self.settings.read());
1117        let font_id = font_cache.default_font(settings.buffer_font_family);
1118        font_cache.em_width(font_id, settings.buffer_font_size)
1119    }
1120
1121    // TODO: Can we make this not return a result?
1122    pub fn max_line_number_width(
1123        &self,
1124        font_cache: &FontCache,
1125        layout_cache: &TextLayoutCache,
1126        app: &AppContext,
1127    ) -> Result<f32> {
1128        let settings = smol::block_on(self.settings.read());
1129        let font_size = settings.buffer_font_size;
1130        let font_id =
1131            font_cache.select_font(settings.buffer_font_family, &FontProperties::new())?;
1132        let digit_count = ((self.buffer.read(app).max_point().row + 1) as f32)
1133            .log10()
1134            .floor() as usize
1135            + 1;
1136
1137        Ok(layout_cache
1138            .layout_str(
1139                "1".repeat(digit_count).as_str(),
1140                font_size,
1141                &[(0..digit_count, font_id)],
1142            )
1143            .width)
1144    }
1145
1146    pub fn layout_line_numbers(
1147        &self,
1148        viewport_height: f32,
1149        font_cache: &FontCache,
1150        layout_cache: &TextLayoutCache,
1151        app: &AppContext,
1152    ) -> Result<Vec<Arc<text_layout::Line>>> {
1153        let display_map = self.display_map.read(app);
1154
1155        let settings = smol::block_on(self.settings.read());
1156        let font_size = settings.buffer_font_size;
1157        let font_id =
1158            font_cache.select_font(settings.buffer_font_family, &FontProperties::new())?;
1159
1160        let start_row = self.scroll_position().y() as usize;
1161        let end_row = cmp::min(
1162            self.max_point(app).row() as usize,
1163            start_row + (viewport_height / self.line_height(font_cache)).ceil() as usize,
1164        );
1165        let line_count = end_row - start_row + 1;
1166
1167        let mut layouts = Vec::with_capacity(line_count);
1168        let mut line_number = String::new();
1169        for buffer_row in display_map.buffer_rows(start_row as u32)?.take(line_count) {
1170            line_number.clear();
1171            write!(&mut line_number, "{}", buffer_row + 1).unwrap();
1172            layouts.push(layout_cache.layout_str(
1173                &line_number,
1174                font_size,
1175                &[(0..line_number.len(), font_id)],
1176            ));
1177        }
1178
1179        Ok(layouts)
1180    }
1181
1182    pub fn layout_lines(
1183        &self,
1184        mut rows: Range<u32>,
1185        font_cache: &FontCache,
1186        layout_cache: &TextLayoutCache,
1187        app: &AppContext,
1188    ) -> Result<Vec<Arc<text_layout::Line>>> {
1189        let display_map = self.display_map.read(app);
1190
1191        rows.end = cmp::min(rows.end, display_map.max_point(app).row() + 1);
1192        if rows.start >= rows.end {
1193            return Ok(Vec::new());
1194        }
1195
1196        let settings = smol::block_on(self.settings.read());
1197        let font_id =
1198            font_cache.select_font(settings.buffer_font_family, &FontProperties::new())?;
1199        let font_size = settings.buffer_font_size;
1200
1201        let mut layouts = Vec::with_capacity(rows.len());
1202        let mut line = String::new();
1203        let mut line_len = 0;
1204        let mut row = rows.start;
1205        let chars = display_map
1206            .chars_at(DisplayPoint::new(rows.start, 0), app)
1207            .unwrap();
1208        for char in chars.chain(Some('\n')) {
1209            if char == '\n' {
1210                layouts.push(layout_cache.layout_str(&line, font_size, &[(0..line_len, font_id)]));
1211                line.clear();
1212                line_len = 0;
1213                row += 1;
1214                if row == rows.end {
1215                    break;
1216                }
1217            } else {
1218                line_len += 1;
1219                line.push(char);
1220            }
1221        }
1222
1223        Ok(layouts)
1224    }
1225
1226    pub fn layout_line(
1227        &self,
1228        row: u32,
1229        font_cache: &FontCache,
1230        layout_cache: &TextLayoutCache,
1231        app: &AppContext,
1232    ) -> Result<Arc<text_layout::Line>> {
1233        let settings = smol::block_on(self.settings.read());
1234        let font_id =
1235            font_cache.select_font(settings.buffer_font_family, &FontProperties::new())?;
1236
1237        let line = self.line(row, app)?;
1238
1239        Ok(layout_cache.layout_str(
1240            &line,
1241            settings.buffer_font_size,
1242            &[(0..self.line_len(row, app)? as usize, font_id)],
1243        ))
1244    }
1245
1246    fn next_blink_epoch(&mut self) -> usize {
1247        self.blink_epoch += 1;
1248        self.blink_epoch
1249    }
1250
1251    fn pause_cursor_blinking(&mut self, ctx: &mut ViewContext<Self>) {
1252        self.cursors_visible = true;
1253        ctx.notify();
1254
1255        let epoch = self.next_blink_epoch();
1256        ctx.spawn(
1257            async move {
1258                Timer::after(CURSOR_BLINK_INTERVAL).await;
1259                epoch
1260            },
1261            Self::resume_cursor_blinking,
1262        )
1263        .detach();
1264    }
1265
1266    fn resume_cursor_blinking(&mut self, epoch: usize, ctx: &mut ViewContext<Self>) {
1267        if epoch == self.blink_epoch {
1268            self.blinking_paused = false;
1269            self.blink_cursors(epoch, ctx);
1270        }
1271    }
1272
1273    fn blink_cursors(&mut self, epoch: usize, ctx: &mut ViewContext<Self>) {
1274        if epoch == self.blink_epoch && self.focused && !self.blinking_paused {
1275            self.cursors_visible = !self.cursors_visible;
1276            ctx.notify();
1277
1278            let epoch = self.next_blink_epoch();
1279            ctx.spawn(
1280                async move {
1281                    Timer::after(CURSOR_BLINK_INTERVAL).await;
1282                    epoch
1283                },
1284                Self::blink_cursors,
1285            )
1286            .detach();
1287        }
1288    }
1289
1290    pub fn cursors_visible(&self) -> bool {
1291        self.cursors_visible
1292    }
1293
1294    fn on_buffer_changed(&mut self, _: ModelHandle<Buffer>, ctx: &mut ViewContext<Self>) {
1295        ctx.notify();
1296    }
1297
1298    fn on_display_map_changed(&mut self, _: ModelHandle<DisplayMap>, ctx: &mut ViewContext<Self>) {
1299        ctx.notify();
1300    }
1301
1302    fn on_buffer_event(
1303        &mut self,
1304        _: ModelHandle<Buffer>,
1305        event: &buffer::Event,
1306        ctx: &mut ViewContext<Self>,
1307    ) {
1308        match event {
1309            buffer::Event::Edited(_) => ctx.emit(Event::Edited),
1310            buffer::Event::Dirtied => ctx.emit(Event::Dirtied),
1311            buffer::Event::Saved => ctx.emit(Event::Saved),
1312            buffer::Event::FileHandleChanged => ctx.emit(Event::FileHandleChanged),
1313        }
1314    }
1315}
1316
1317pub enum Event {
1318    Activate,
1319    Edited,
1320    Blurred,
1321    Dirtied,
1322    Saved,
1323    FileHandleChanged,
1324}
1325
1326impl Entity for BufferView {
1327    type Event = Event;
1328}
1329
1330impl View for BufferView {
1331    fn render<'a>(&self, app: &AppContext) -> ElementBox {
1332        BufferElement::new(self.handle.upgrade(app).unwrap()).boxed()
1333    }
1334
1335    fn ui_name() -> &'static str {
1336        "BufferView"
1337    }
1338
1339    fn on_focus(&mut self, ctx: &mut ViewContext<Self>) {
1340        self.focused = true;
1341        self.blink_cursors(self.blink_epoch, ctx);
1342    }
1343
1344    fn on_blur(&mut self, ctx: &mut ViewContext<Self>) {
1345        self.focused = false;
1346        self.cursors_visible = false;
1347        ctx.emit(Event::Blurred);
1348        ctx.notify();
1349    }
1350}
1351
1352impl workspace::Item for Buffer {
1353    type View = BufferView;
1354
1355    fn build_view(
1356        buffer: ModelHandle<Self>,
1357        settings: watch::Receiver<Settings>,
1358        ctx: &mut ViewContext<Self::View>,
1359    ) -> Self::View {
1360        BufferView::for_buffer(buffer, settings, ctx)
1361    }
1362}
1363
1364impl workspace::ItemView for BufferView {
1365    fn should_activate_item_on_event(event: &Self::Event) -> bool {
1366        matches!(event, Event::Activate)
1367    }
1368
1369    fn should_update_tab_on_event(event: &Self::Event) -> bool {
1370        matches!(
1371            event,
1372            Event::Saved | Event::Dirtied | Event::FileHandleChanged
1373        )
1374    }
1375
1376    fn title(&self, app: &AppContext) -> std::string::String {
1377        if let Some(path) = self.buffer.read(app).path() {
1378            path.file_name()
1379                .expect("buffer's path is always to a file")
1380                .to_string_lossy()
1381                .into()
1382        } else {
1383            "untitled".into()
1384        }
1385    }
1386
1387    fn entry_id(&self, app: &AppContext) -> Option<(usize, Arc<Path>)> {
1388        self.buffer.read(app).entry_id()
1389    }
1390
1391    fn clone_on_split(&self, ctx: &mut ViewContext<Self>) -> Option<Self>
1392    where
1393        Self: Sized,
1394    {
1395        let clone = BufferView::for_buffer(self.buffer.clone(), self.settings.clone(), ctx);
1396        *clone.scroll_position.lock() = *self.scroll_position.lock();
1397        Some(clone)
1398    }
1399
1400    fn save(&self, ctx: &mut ViewContext<Self>) -> LocalBoxFuture<'static, Result<()>> {
1401        self.buffer.update(ctx, |buffer, ctx| buffer.save(ctx))
1402    }
1403
1404    fn is_dirty(&self, ctx: &AppContext) -> bool {
1405        self.buffer.read(ctx).is_dirty()
1406    }
1407}
1408
1409#[cfg(test)]
1410mod tests {
1411    use super::*;
1412    use crate::{editor::Point, settings, test::sample_text};
1413    use anyhow::Error;
1414    use gpui::App;
1415    use unindent::Unindent;
1416
1417    #[test]
1418    fn test_selection_with_mouse() {
1419        App::test((), |app| {
1420            let buffer =
1421                app.add_model(|ctx| Buffer::new(0, "aaaaaa\nbbbbbb\ncccccc\ndddddd\n", ctx));
1422            let settings = settings::channel(&app.font_cache()).unwrap().1;
1423            let (_, buffer_view) =
1424                app.add_window(|ctx| BufferView::for_buffer(buffer, settings, ctx));
1425
1426            buffer_view.update(app, |view, ctx| {
1427                view.begin_selection(DisplayPoint::new(2, 2), false, ctx);
1428            });
1429
1430            let view = buffer_view.read(app);
1431            let selections = view
1432                .selections_in_range(
1433                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1434                    app.as_ref(),
1435                )
1436                .collect::<Vec<_>>();
1437            assert_eq!(
1438                selections,
1439                [DisplayPoint::new(2, 2)..DisplayPoint::new(2, 2)]
1440            );
1441
1442            buffer_view.update(app, |view, ctx| {
1443                view.update_selection(DisplayPoint::new(3, 3), Vector2F::zero(), ctx);
1444            });
1445
1446            let view = buffer_view.read(app);
1447            let selections = view
1448                .selections_in_range(
1449                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1450                    app.as_ref(),
1451                )
1452                .collect::<Vec<_>>();
1453            assert_eq!(
1454                selections,
1455                [DisplayPoint::new(2, 2)..DisplayPoint::new(3, 3)]
1456            );
1457
1458            buffer_view.update(app, |view, ctx| {
1459                view.update_selection(DisplayPoint::new(1, 1), Vector2F::zero(), ctx);
1460            });
1461
1462            let view = buffer_view.read(app);
1463            let selections = view
1464                .selections_in_range(
1465                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1466                    app.as_ref(),
1467                )
1468                .collect::<Vec<_>>();
1469            assert_eq!(
1470                selections,
1471                [DisplayPoint::new(2, 2)..DisplayPoint::new(1, 1)]
1472            );
1473
1474            buffer_view.update(app, |view, ctx| {
1475                view.end_selection(ctx);
1476                view.update_selection(DisplayPoint::new(3, 3), Vector2F::zero(), ctx);
1477            });
1478
1479            let view = buffer_view.read(app);
1480            let selections = view
1481                .selections_in_range(
1482                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1483                    app.as_ref(),
1484                )
1485                .collect::<Vec<_>>();
1486            assert_eq!(
1487                selections,
1488                [DisplayPoint::new(2, 2)..DisplayPoint::new(1, 1)]
1489            );
1490
1491            buffer_view.update(app, |view, ctx| {
1492                view.begin_selection(DisplayPoint::new(3, 3), true, ctx);
1493                view.update_selection(DisplayPoint::new(0, 0), Vector2F::zero(), ctx);
1494            });
1495
1496            let view = buffer_view.read(app);
1497            let selections = view
1498                .selections_in_range(
1499                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1500                    app.as_ref(),
1501                )
1502                .collect::<Vec<_>>();
1503            assert_eq!(
1504                selections,
1505                [
1506                    DisplayPoint::new(2, 2)..DisplayPoint::new(1, 1),
1507                    DisplayPoint::new(3, 3)..DisplayPoint::new(0, 0)
1508                ]
1509            );
1510
1511            buffer_view.update(app, |view, ctx| {
1512                view.end_selection(ctx);
1513            });
1514
1515            let view = buffer_view.read(app);
1516            let selections = view
1517                .selections_in_range(
1518                    DisplayPoint::zero()..view.max_point(app.as_ref()),
1519                    app.as_ref(),
1520                )
1521                .collect::<Vec<_>>();
1522            assert_eq!(
1523                selections,
1524                [DisplayPoint::new(3, 3)..DisplayPoint::new(0, 0)]
1525            );
1526        });
1527    }
1528
1529    #[test]
1530    fn test_layout_line_numbers() {
1531        App::test((), |app| {
1532            let layout_cache = TextLayoutCache::new(app.platform().fonts());
1533            let font_cache = app.font_cache().clone();
1534
1535            let buffer = app.add_model(|ctx| Buffer::new(0, sample_text(6, 6), ctx));
1536
1537            let settings = settings::channel(&font_cache).unwrap().1;
1538            let (_, view) =
1539                app.add_window(|ctx| BufferView::for_buffer(buffer.clone(), settings, ctx));
1540
1541            let layouts = view
1542                .read(app)
1543                .layout_line_numbers(1000.0, &font_cache, &layout_cache, app.as_ref())
1544                .unwrap();
1545            assert_eq!(layouts.len(), 6);
1546        })
1547    }
1548
1549    #[test]
1550    fn test_fold() {
1551        App::test((), |app| {
1552            let buffer = app.add_model(|ctx| {
1553                Buffer::new(
1554                    0,
1555                    "
1556                    impl Foo {
1557                        // Hello!
1558
1559                        fn a() {
1560                            1
1561                        }
1562
1563                        fn b() {
1564                            2
1565                        }
1566
1567                        fn c() {
1568                            3
1569                        }
1570                    }
1571                "
1572                    .unindent(),
1573                    ctx,
1574                )
1575            });
1576            let settings = settings::channel(&app.font_cache()).unwrap().1;
1577            let (_, view) =
1578                app.add_window(|ctx| BufferView::for_buffer(buffer.clone(), settings, ctx));
1579
1580            view.update(app, |view, ctx| {
1581                view.select_display_ranges(
1582                    &[DisplayPoint::new(8, 0)..DisplayPoint::new(12, 0)],
1583                    ctx,
1584                )
1585                .unwrap();
1586                view.fold(&(), ctx);
1587                assert_eq!(
1588                    view.text(ctx.as_ref()),
1589                    "
1590                    impl Foo {
1591                        // Hello!
1592
1593                        fn a() {
1594                            1
1595                        }
1596
1597                        fn b() {…
1598                        }
1599
1600                        fn c() {…
1601                        }
1602                    }
1603                "
1604                    .unindent(),
1605                );
1606
1607                view.fold(&(), ctx);
1608                assert_eq!(
1609                    view.text(ctx.as_ref()),
1610                    "
1611                    impl Foo {…
1612                    }
1613                "
1614                    .unindent(),
1615                );
1616
1617                view.unfold(&(), ctx);
1618                assert_eq!(
1619                    view.text(ctx.as_ref()),
1620                    "
1621                    impl Foo {
1622                        // Hello!
1623
1624                        fn a() {
1625                            1
1626                        }
1627
1628                        fn b() {…
1629                        }
1630
1631                        fn c() {…
1632                        }
1633                    }
1634                "
1635                    .unindent(),
1636                );
1637
1638                view.unfold(&(), ctx);
1639                assert_eq!(view.text(ctx.as_ref()), buffer.read(ctx).text());
1640            });
1641        });
1642    }
1643
1644    #[test]
1645    fn test_move_cursor() -> Result<()> {
1646        App::test((), |app| {
1647            let buffer = app.add_model(|ctx| Buffer::new(0, sample_text(6, 6), ctx));
1648            let settings = settings::channel(&app.font_cache()).unwrap().1;
1649            let (_, view) =
1650                app.add_window(|ctx| BufferView::for_buffer(buffer.clone(), settings, ctx));
1651
1652            buffer.update(app, |buffer, ctx| {
1653                buffer.edit(
1654                    vec![
1655                        Point::new(1, 0)..Point::new(1, 0),
1656                        Point::new(1, 1)..Point::new(1, 1),
1657                    ],
1658                    "\t",
1659                    Some(ctx),
1660                )
1661            })?;
1662
1663            view.update(app, |view, ctx| {
1664                view.move_down(&(), ctx);
1665                assert_eq!(
1666                    view.selection_ranges(ctx.as_ref()),
1667                    &[DisplayPoint::new(1, 0)..DisplayPoint::new(1, 0)]
1668                );
1669                view.move_right(&(), ctx);
1670                assert_eq!(
1671                    view.selection_ranges(ctx.as_ref()),
1672                    &[DisplayPoint::new(1, 4)..DisplayPoint::new(1, 4)]
1673                );
1674                Ok::<(), Error>(())
1675            })?;
1676
1677            Ok(())
1678        })
1679    }
1680
1681    #[test]
1682    fn test_backspace() {
1683        App::test((), |app| {
1684            let buffer = app.add_model(|ctx| {
1685                Buffer::new(
1686                    0,
1687                    "one two three\nfour five six\nseven eight nine\nten\n",
1688                    ctx,
1689                )
1690            });
1691            let settings = settings::channel(&app.font_cache()).unwrap().1;
1692            let (_, view) =
1693                app.add_window(|ctx| BufferView::for_buffer(buffer.clone(), settings, ctx));
1694
1695            view.update(app, |view, ctx| {
1696                view.select_display_ranges(
1697                    &[
1698                        // an empty selection - the preceding character is deleted
1699                        DisplayPoint::new(0, 2)..DisplayPoint::new(0, 2),
1700                        // one character selected - it is deleted
1701                        DisplayPoint::new(1, 3)..DisplayPoint::new(1, 4),
1702                        // a line suffix selected - it is deleted
1703                        DisplayPoint::new(2, 6)..DisplayPoint::new(3, 0),
1704                    ],
1705                    ctx,
1706                )
1707                .unwrap();
1708                view.backspace(&(), ctx);
1709            });
1710
1711            assert_eq!(
1712                buffer.read(app).text(),
1713                "oe two three\nfou five six\nseven ten\n"
1714            );
1715        })
1716    }
1717
1718    #[test]
1719    fn test_clipboard() {
1720        App::test((), |app| {
1721            let buffer = app.add_model(|ctx| Buffer::new(0, "one two three four five six ", ctx));
1722            let settings = settings::channel(&app.font_cache()).unwrap().1;
1723            let view = app
1724                .add_window(|ctx| BufferView::for_buffer(buffer.clone(), settings, ctx))
1725                .1;
1726
1727            // Cut with three selections. Clipboard text is divided into three slices.
1728            view.update(app, |view, ctx| {
1729                view.select_ranges(&[0..4, 8..14, 19..24], ctx).unwrap();
1730                view.cut(&(), ctx);
1731            });
1732            assert_eq!(view.read(app).text(app.as_ref()), "two four six ");
1733
1734            // Paste with three cursors. Each cursor pastes one slice of the clipboard text.
1735            view.update(app, |view, ctx| {
1736                view.select_ranges(&[4..4, 9..9, 13..13], ctx).unwrap();
1737                view.paste(&(), ctx);
1738            });
1739            assert_eq!(
1740                view.read(app).text(app.as_ref()),
1741                "two one four three six five "
1742            );
1743            assert_eq!(
1744                view.read(app).selection_ranges(app.as_ref()),
1745                &[
1746                    DisplayPoint::new(0, 8)..DisplayPoint::new(0, 8),
1747                    DisplayPoint::new(0, 19)..DisplayPoint::new(0, 19),
1748                    DisplayPoint::new(0, 28)..DisplayPoint::new(0, 28)
1749                ]
1750            );
1751
1752            // Paste again but with only two cursors. Since the number of cursors doesn't
1753            // match the number of slices in the clipboard, the entire clipboard text
1754            // is pasted at each cursor.
1755            view.update(app, |view, ctx| {
1756                view.select_ranges(&[0..0, 28..28], ctx).unwrap();
1757                view.insert(&"( ".to_string(), ctx);
1758                view.paste(&(), ctx);
1759                view.insert(&") ".to_string(), ctx);
1760            });
1761            assert_eq!(
1762                view.read(app).text(app.as_ref()),
1763                "( one three five ) two one four three six five ( one three five ) "
1764            );
1765
1766            view.update(app, |view, ctx| {
1767                view.select_ranges(&[0..0], ctx).unwrap();
1768                view.insert(&"123\n4567\n89\n".to_string(), ctx);
1769            });
1770            assert_eq!(
1771                view.read(app).text(app.as_ref()),
1772                "123\n4567\n89\n( one three five ) two one four three six five ( one three five ) "
1773            );
1774
1775            // Cut with three selections, one of which is full-line.
1776            view.update(app, |view, ctx| {
1777                view.select_display_ranges(
1778                    &[
1779                        DisplayPoint::new(0, 1)..DisplayPoint::new(0, 2),
1780                        DisplayPoint::new(1, 1)..DisplayPoint::new(1, 1),
1781                        DisplayPoint::new(2, 0)..DisplayPoint::new(2, 1),
1782                    ],
1783                    ctx,
1784                )
1785                .unwrap();
1786                view.cut(&(), ctx);
1787            });
1788            assert_eq!(
1789                view.read(app).text(app.as_ref()),
1790                "13\n9\n( one three five ) two one four three six five ( one three five ) "
1791            );
1792
1793            // Paste with three selections, noticing how the copied selection that was full-line
1794            // gets inserted before the second cursor.
1795            view.update(app, |view, ctx| {
1796                view.select_display_ranges(
1797                    &[
1798                        DisplayPoint::new(0, 1)..DisplayPoint::new(0, 1),
1799                        DisplayPoint::new(1, 1)..DisplayPoint::new(1, 1),
1800                        DisplayPoint::new(2, 2)..DisplayPoint::new(2, 3),
1801                    ],
1802                    ctx,
1803                )
1804                .unwrap();
1805                view.paste(&(), ctx);
1806            });
1807            assert_eq!(
1808                view.read(app).text(app.as_ref()),
1809                "123\n4567\n9\n( 8ne three five ) two one four three six five ( one three five ) "
1810            );
1811            assert_eq!(
1812                view.read(app).selection_ranges(app.as_ref()),
1813                &[
1814                    DisplayPoint::new(0, 2)..DisplayPoint::new(0, 2),
1815                    DisplayPoint::new(2, 1)..DisplayPoint::new(2, 1),
1816                    DisplayPoint::new(3, 3)..DisplayPoint::new(3, 3),
1817                ]
1818            );
1819
1820            // Copy with a single cursor only, which writes the whole line into the clipboard.
1821            view.update(app, |view, ctx| {
1822                view.select_display_ranges(
1823                    &[DisplayPoint::new(0, 1)..DisplayPoint::new(0, 1)],
1824                    ctx,
1825                )
1826                .unwrap();
1827                view.copy(&(), ctx);
1828            });
1829
1830            // Paste with three selections, noticing how the copied full-line selection is inserted
1831            // before the empty selections but replaces the selection that is non-empty.
1832            view.update(app, |view, ctx| {
1833                view.select_display_ranges(
1834                    &[
1835                        DisplayPoint::new(0, 1)..DisplayPoint::new(0, 1),
1836                        DisplayPoint::new(1, 0)..DisplayPoint::new(1, 2),
1837                        DisplayPoint::new(2, 1)..DisplayPoint::new(2, 1),
1838                    ],
1839                    ctx,
1840                )
1841                .unwrap();
1842                view.paste(&(), ctx);
1843            });
1844            assert_eq!(
1845                view.read(app).text(app.as_ref()),
1846                "123\n123\n123\n67\n123\n9\n( 8ne three five ) two one four three six five ( one three five ) "
1847            );
1848            assert_eq!(
1849                view.read(app).selection_ranges(app.as_ref()),
1850                &[
1851                    DisplayPoint::new(1, 1)..DisplayPoint::new(1, 1),
1852                    DisplayPoint::new(3, 0)..DisplayPoint::new(3, 0),
1853                    DisplayPoint::new(5, 1)..DisplayPoint::new(5, 1),
1854                ]
1855            );
1856        });
1857    }
1858
1859    #[test]
1860    fn test_select_all() {
1861        App::test((), |app| {
1862            let buffer = app.add_model(|ctx| Buffer::new(0, "abc\nde\nfgh", ctx));
1863            let settings = settings::channel(&app.font_cache()).unwrap().1;
1864            let (_, view) = app.add_window(|ctx| BufferView::for_buffer(buffer, settings, ctx));
1865            view.update(app, |b, ctx| b.select_all(&(), ctx));
1866            assert_eq!(
1867                view.read(app).selection_ranges(app.as_ref()),
1868                &[DisplayPoint::new(0, 0)..DisplayPoint::new(2, 3)]
1869            );
1870        });
1871    }
1872
1873    impl BufferView {
1874        fn selection_ranges(&self, app: &AppContext) -> Vec<Range<DisplayPoint>> {
1875            self.selections_in_range(DisplayPoint::zero()..self.max_point(app), app)
1876                .collect::<Vec<_>>()
1877        }
1878    }
1879}