wrap_map.rs

   1use super::{
   2    fold_map,
   3    tab_map::{self, TabEdit, TabPoint, TabSnapshot},
   4};
   5use gpui::{
   6    fonts::FontId, text_layout::LineWrapper, Entity, ModelContext, ModelHandle, MutableAppContext,
   7    Task,
   8};
   9use language::{multi_buffer::MultiBufferSnapshot, Chunk, Point};
  10use lazy_static::lazy_static;
  11use smol::future::yield_now;
  12use std::{collections::VecDeque, mem, ops::Range, time::Duration};
  13use sum_tree::{Bias, Cursor, SumTree};
  14use text::Patch;
  15use theme::SyntaxTheme;
  16
  17pub use super::tab_map::TextSummary;
  18pub type WrapEdit = text::Edit<u32>;
  19
  20pub struct WrapMap {
  21    snapshot: WrapSnapshot,
  22    pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
  23    interpolated_edits: Patch<u32>,
  24    edits_since_sync: Patch<u32>,
  25    wrap_width: Option<f32>,
  26    background_task: Option<Task<()>>,
  27    font: (FontId, f32),
  28}
  29
  30impl Entity for WrapMap {
  31    type Event = ();
  32}
  33
  34#[derive(Clone)]
  35pub struct WrapSnapshot {
  36    tab_snapshot: TabSnapshot,
  37    transforms: SumTree<Transform>,
  38    interpolated: bool,
  39}
  40
  41#[derive(Clone, Debug, Default, Eq, PartialEq)]
  42struct Transform {
  43    summary: TransformSummary,
  44    display_text: Option<&'static str>,
  45}
  46
  47#[derive(Clone, Debug, Default, Eq, PartialEq)]
  48struct TransformSummary {
  49    input: TextSummary,
  50    output: TextSummary,
  51}
  52
  53#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  54pub struct WrapPoint(pub super::Point);
  55
  56pub struct WrapChunks<'a> {
  57    input_chunks: tab_map::TabChunks<'a>,
  58    input_chunk: Chunk<'a>,
  59    output_position: WrapPoint,
  60    max_output_row: u32,
  61    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  62}
  63
  64pub struct WrapBufferRows<'a> {
  65    input_buffer_rows: fold_map::FoldBufferRows<'a>,
  66    input_buffer_row: u32,
  67    output_row: u32,
  68    soft_wrapped: bool,
  69    max_output_row: u32,
  70    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  71}
  72
  73impl WrapMap {
  74    pub fn new(
  75        tab_snapshot: TabSnapshot,
  76        font_id: FontId,
  77        font_size: f32,
  78        wrap_width: Option<f32>,
  79        cx: &mut MutableAppContext,
  80    ) -> (ModelHandle<Self>, WrapSnapshot) {
  81        let handle = cx.add_model(|cx| {
  82            let mut this = Self {
  83                font: (font_id, font_size),
  84                wrap_width: None,
  85                pending_edits: Default::default(),
  86                interpolated_edits: Default::default(),
  87                edits_since_sync: Default::default(),
  88                snapshot: WrapSnapshot::new(tab_snapshot),
  89                background_task: None,
  90            };
  91            this.set_wrap_width(wrap_width, cx);
  92            mem::take(&mut this.edits_since_sync);
  93            this
  94        });
  95        let snapshot = handle.read(cx).snapshot.clone();
  96        (handle, snapshot)
  97    }
  98
  99    #[cfg(test)]
 100    pub fn is_rewrapping(&self) -> bool {
 101        self.background_task.is_some()
 102    }
 103
 104    pub fn sync(
 105        &mut self,
 106        tab_snapshot: TabSnapshot,
 107        edits: Vec<TabEdit>,
 108        cx: &mut ModelContext<Self>,
 109    ) -> (WrapSnapshot, Vec<WrapEdit>) {
 110        if self.wrap_width.is_some() {
 111            self.pending_edits.push_back((tab_snapshot, edits));
 112            self.flush_edits(cx);
 113        } else {
 114            self.edits_since_sync = self
 115                .edits_since_sync
 116                .compose(&self.snapshot.interpolate(tab_snapshot, &edits));
 117            self.snapshot.interpolated = false;
 118        }
 119
 120        (
 121            self.snapshot.clone(),
 122            mem::take(&mut self.edits_since_sync).into_inner(),
 123        )
 124    }
 125
 126    pub fn set_font(&mut self, font_id: FontId, font_size: f32, cx: &mut ModelContext<Self>) {
 127        if (font_id, font_size) != self.font {
 128            self.font = (font_id, font_size);
 129            self.rewrap(cx)
 130        }
 131    }
 132
 133    pub fn set_wrap_width(&mut self, wrap_width: Option<f32>, cx: &mut ModelContext<Self>) -> bool {
 134        if wrap_width == self.wrap_width {
 135            return false;
 136        }
 137
 138        self.wrap_width = wrap_width;
 139        self.rewrap(cx);
 140        true
 141    }
 142
 143    fn rewrap(&mut self, cx: &mut ModelContext<Self>) {
 144        self.background_task.take();
 145        self.interpolated_edits.clear();
 146        self.pending_edits.clear();
 147
 148        if let Some(wrap_width) = self.wrap_width {
 149            let mut new_snapshot = self.snapshot.clone();
 150            let font_cache = cx.font_cache().clone();
 151            let (font_id, font_size) = self.font;
 152            let task = cx.background().spawn(async move {
 153                let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 154                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 155                let range = TabPoint::zero()..tab_snapshot.max_point();
 156                let edits = new_snapshot
 157                    .update(
 158                        tab_snapshot,
 159                        &[TabEdit {
 160                            old: range.clone(),
 161                            new: range.clone(),
 162                        }],
 163                        wrap_width,
 164                        &mut line_wrapper,
 165                    )
 166                    .await;
 167                (new_snapshot, edits)
 168            });
 169
 170            match cx
 171                .background()
 172                .block_with_timeout(Duration::from_millis(5), task)
 173            {
 174                Ok((snapshot, edits)) => {
 175                    self.snapshot = snapshot;
 176                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 177                    cx.notify();
 178                }
 179                Err(wrap_task) => {
 180                    self.background_task = Some(cx.spawn(|this, mut cx| async move {
 181                        let (snapshot, edits) = wrap_task.await;
 182                        this.update(&mut cx, |this, cx| {
 183                            this.snapshot = snapshot;
 184                            this.edits_since_sync = this
 185                                .edits_since_sync
 186                                .compose(mem::take(&mut this.interpolated_edits).invert())
 187                                .compose(&edits);
 188                            this.background_task = None;
 189                            this.flush_edits(cx);
 190                            cx.notify();
 191                        });
 192                    }));
 193                }
 194            }
 195        } else {
 196            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 197            self.snapshot.transforms = SumTree::new();
 198            let summary = self.snapshot.tab_snapshot.text_summary();
 199            if !summary.lines.is_zero() {
 200                self.snapshot
 201                    .transforms
 202                    .push(Transform::isomorphic(summary), &());
 203            }
 204            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 205            self.snapshot.interpolated = false;
 206            self.edits_since_sync = self.edits_since_sync.compose(&Patch::new(vec![WrapEdit {
 207                old: 0..old_rows,
 208                new: 0..new_rows,
 209            }]));
 210        }
 211    }
 212
 213    fn flush_edits(&mut self, cx: &mut ModelContext<Self>) {
 214        if !self.snapshot.interpolated {
 215            let mut to_remove_len = 0;
 216            for (tab_snapshot, _) in &self.pending_edits {
 217                if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 218                    to_remove_len += 1;
 219                } else {
 220                    break;
 221                }
 222            }
 223            self.pending_edits.drain(..to_remove_len);
 224        }
 225
 226        if self.pending_edits.is_empty() {
 227            return;
 228        }
 229
 230        if let Some(wrap_width) = self.wrap_width {
 231            if self.background_task.is_none() {
 232                let pending_edits = self.pending_edits.clone();
 233                let mut snapshot = self.snapshot.clone();
 234                let font_cache = cx.font_cache().clone();
 235                let (font_id, font_size) = self.font;
 236                let update_task = cx.background().spawn(async move {
 237                    let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 238
 239                    let mut edits = Patch::default();
 240                    for (tab_snapshot, tab_edits) in pending_edits {
 241                        let wrap_edits = snapshot
 242                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 243                            .await;
 244                        edits = edits.compose(&wrap_edits);
 245                    }
 246                    (snapshot, edits)
 247                });
 248
 249                match cx
 250                    .background()
 251                    .block_with_timeout(Duration::from_millis(1), update_task)
 252                {
 253                    Ok((snapshot, output_edits)) => {
 254                        self.snapshot = snapshot;
 255                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 256                    }
 257                    Err(update_task) => {
 258                        self.background_task = Some(cx.spawn(|this, mut cx| async move {
 259                            let (snapshot, edits) = update_task.await;
 260                            this.update(&mut cx, |this, cx| {
 261                                this.snapshot = snapshot;
 262                                this.edits_since_sync = this
 263                                    .edits_since_sync
 264                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 265                                    .compose(&edits);
 266                                this.background_task = None;
 267                                this.flush_edits(cx);
 268                                cx.notify();
 269                            });
 270                        }));
 271                    }
 272                }
 273            }
 274        }
 275
 276        let was_interpolated = self.snapshot.interpolated;
 277        let mut to_remove_len = 0;
 278        for (tab_snapshot, edits) in &self.pending_edits {
 279            if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 280                to_remove_len += 1;
 281            } else {
 282                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), &edits);
 283                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 284                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 285            }
 286        }
 287
 288        if !was_interpolated {
 289            self.pending_edits.drain(..to_remove_len);
 290        }
 291    }
 292}
 293
 294impl WrapSnapshot {
 295    fn new(tab_snapshot: TabSnapshot) -> Self {
 296        let mut transforms = SumTree::new();
 297        let extent = tab_snapshot.text_summary();
 298        if !extent.lines.is_zero() {
 299            transforms.push(Transform::isomorphic(extent), &());
 300        }
 301        Self {
 302            transforms,
 303            tab_snapshot,
 304            interpolated: true,
 305        }
 306    }
 307
 308    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 309        self.tab_snapshot.buffer_snapshot()
 310    }
 311
 312    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 313        let mut new_transforms;
 314        if tab_edits.is_empty() {
 315            new_transforms = self.transforms.clone();
 316        } else {
 317            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 318
 319            let mut tab_edits_iter = tab_edits.iter().peekable();
 320            new_transforms =
 321                old_cursor.slice(&tab_edits_iter.peek().unwrap().old.start, Bias::Right, &());
 322
 323            while let Some(edit) = tab_edits_iter.next() {
 324                if edit.new.start > TabPoint::from(new_transforms.summary().input.lines) {
 325                    let summary = new_tab_snapshot.text_summary_for_range(
 326                        TabPoint::from(new_transforms.summary().input.lines)..edit.new.start,
 327                    );
 328                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 329                }
 330
 331                if !edit.new.is_empty() {
 332                    new_transforms.push_or_extend(Transform::isomorphic(
 333                        new_tab_snapshot.text_summary_for_range(edit.new.clone()),
 334                    ));
 335                }
 336
 337                old_cursor.seek_forward(&edit.old.end, Bias::Right, &());
 338                if let Some(next_edit) = tab_edits_iter.peek() {
 339                    if next_edit.old.start > old_cursor.end(&()) {
 340                        if old_cursor.end(&()) > edit.old.end {
 341                            let summary = self
 342                                .tab_snapshot
 343                                .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 344                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 345                        }
 346
 347                        old_cursor.next(&());
 348                        new_transforms.push_tree(
 349                            old_cursor.slice(&next_edit.old.start, Bias::Right, &()),
 350                            &(),
 351                        );
 352                    }
 353                } else {
 354                    if old_cursor.end(&()) > edit.old.end {
 355                        let summary = self
 356                            .tab_snapshot
 357                            .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 358                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 359                    }
 360                    old_cursor.next(&());
 361                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 362                }
 363            }
 364        }
 365
 366        let old_snapshot = mem::replace(
 367            self,
 368            WrapSnapshot {
 369                tab_snapshot: new_tab_snapshot,
 370                transforms: new_transforms,
 371                interpolated: true,
 372            },
 373        );
 374        self.check_invariants();
 375        old_snapshot.compute_edits(tab_edits, self)
 376    }
 377
 378    async fn update(
 379        &mut self,
 380        new_tab_snapshot: TabSnapshot,
 381        tab_edits: &[TabEdit],
 382        wrap_width: f32,
 383        line_wrapper: &mut LineWrapper,
 384    ) -> Patch<u32> {
 385        #[derive(Debug)]
 386        struct RowEdit {
 387            old_rows: Range<u32>,
 388            new_rows: Range<u32>,
 389        }
 390
 391        let mut tab_edits_iter = tab_edits.into_iter().peekable();
 392        let mut row_edits = Vec::new();
 393        while let Some(edit) = tab_edits_iter.next() {
 394            let mut row_edit = RowEdit {
 395                old_rows: edit.old.start.row()..edit.old.end.row() + 1,
 396                new_rows: edit.new.start.row()..edit.new.end.row() + 1,
 397            };
 398
 399            while let Some(next_edit) = tab_edits_iter.peek() {
 400                if next_edit.old.start.row() <= row_edit.old_rows.end {
 401                    row_edit.old_rows.end = next_edit.old.end.row() + 1;
 402                    row_edit.new_rows.end = next_edit.new.end.row() + 1;
 403                    tab_edits_iter.next();
 404                } else {
 405                    break;
 406                }
 407            }
 408
 409            row_edits.push(row_edit);
 410        }
 411
 412        let mut new_transforms;
 413        if row_edits.is_empty() {
 414            new_transforms = self.transforms.clone();
 415        } else {
 416            let mut row_edits = row_edits.into_iter().peekable();
 417            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 418
 419            new_transforms = old_cursor.slice(
 420                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 421                Bias::Right,
 422                &(),
 423            );
 424
 425            while let Some(edit) = row_edits.next() {
 426                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 427                    let summary = new_tab_snapshot.text_summary_for_range(
 428                        TabPoint(new_transforms.summary().input.lines)
 429                            ..TabPoint::new(edit.new_rows.start, 0),
 430                    );
 431                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 432                }
 433
 434                let mut line = String::new();
 435                let mut remaining = None;
 436                let mut chunks = new_tab_snapshot.chunks(
 437                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 438                    None,
 439                );
 440                let mut edit_transforms = Vec::<Transform>::new();
 441                for _ in edit.new_rows.start..edit.new_rows.end {
 442                    while let Some(chunk) =
 443                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 444                    {
 445                        if let Some(ix) = chunk.find('\n') {
 446                            line.push_str(&chunk[..ix + 1]);
 447                            remaining = Some(&chunk[ix + 1..]);
 448                            break;
 449                        } else {
 450                            line.push_str(chunk)
 451                        }
 452                    }
 453
 454                    if line.is_empty() {
 455                        break;
 456                    }
 457
 458                    let mut prev_boundary_ix = 0;
 459                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 460                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 461                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 462                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 463                        prev_boundary_ix = boundary.ix;
 464                    }
 465
 466                    if prev_boundary_ix < line.len() {
 467                        push_isomorphic(
 468                            &mut edit_transforms,
 469                            TextSummary::from(&line[prev_boundary_ix..]),
 470                        );
 471                    }
 472
 473                    line.clear();
 474                    yield_now().await;
 475                }
 476
 477                let mut edit_transforms = edit_transforms.into_iter();
 478                if let Some(transform) = edit_transforms.next() {
 479                    new_transforms.push_or_extend(transform);
 480                }
 481                new_transforms.extend(edit_transforms, &());
 482
 483                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 484                if let Some(next_edit) = row_edits.peek() {
 485                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 486                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 487                            let summary = self.tab_snapshot.text_summary_for_range(
 488                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 489                            );
 490                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 491                        }
 492                        old_cursor.next(&());
 493                        new_transforms.push_tree(
 494                            old_cursor.slice(
 495                                &TabPoint::new(next_edit.old_rows.start, 0),
 496                                Bias::Right,
 497                                &(),
 498                            ),
 499                            &(),
 500                        );
 501                    }
 502                } else {
 503                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 504                        let summary = self.tab_snapshot.text_summary_for_range(
 505                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 506                        );
 507                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 508                    }
 509                    old_cursor.next(&());
 510                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 511                }
 512            }
 513        }
 514
 515        let old_snapshot = mem::replace(
 516            self,
 517            WrapSnapshot {
 518                tab_snapshot: new_tab_snapshot,
 519                transforms: new_transforms,
 520                interpolated: false,
 521            },
 522        );
 523        self.check_invariants();
 524        old_snapshot.compute_edits(tab_edits, self)
 525    }
 526
 527    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &WrapSnapshot) -> Patch<u32> {
 528        let mut wrap_edits = Vec::new();
 529        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 530        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 531        for mut tab_edit in tab_edits.iter().cloned() {
 532            tab_edit.old.start.0.column = 0;
 533            tab_edit.old.end.0 += Point::new(1, 0);
 534            tab_edit.new.start.0.column = 0;
 535            tab_edit.new.end.0 += Point::new(1, 0);
 536
 537            old_cursor.seek(&tab_edit.old.start, Bias::Right, &());
 538            let mut old_start = old_cursor.start().output.lines;
 539            old_start += tab_edit.old.start.0 - old_cursor.start().input.lines;
 540
 541            old_cursor.seek(&tab_edit.old.end, Bias::Right, &());
 542            let mut old_end = old_cursor.start().output.lines;
 543            old_end += tab_edit.old.end.0 - old_cursor.start().input.lines;
 544
 545            new_cursor.seek(&tab_edit.new.start, Bias::Right, &());
 546            let mut new_start = new_cursor.start().output.lines;
 547            new_start += tab_edit.new.start.0 - new_cursor.start().input.lines;
 548
 549            new_cursor.seek(&tab_edit.new.end, Bias::Right, &());
 550            let mut new_end = new_cursor.start().output.lines;
 551            new_end += tab_edit.new.end.0 - new_cursor.start().input.lines;
 552
 553            wrap_edits.push(WrapEdit {
 554                old: old_start.row..old_end.row,
 555                new: new_start.row..new_end.row,
 556            });
 557        }
 558
 559        consolidate_wrap_edits(&mut wrap_edits);
 560        Patch::new(wrap_edits)
 561    }
 562
 563    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 564        self.chunks(wrap_row..self.max_point().row() + 1, None)
 565            .map(|h| h.text)
 566    }
 567
 568    pub fn chunks<'a>(
 569        &'a self,
 570        rows: Range<u32>,
 571        theme: Option<&'a SyntaxTheme>,
 572    ) -> WrapChunks<'a> {
 573        let output_start = WrapPoint::new(rows.start, 0);
 574        let output_end = WrapPoint::new(rows.end, 0);
 575        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 576        transforms.seek(&output_start, Bias::Right, &());
 577        let mut input_start = TabPoint(transforms.start().1 .0);
 578        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 579            input_start.0 += output_start.0 - transforms.start().0 .0;
 580        }
 581        let input_end = self
 582            .to_tab_point(output_end)
 583            .min(self.tab_snapshot.max_point());
 584        WrapChunks {
 585            input_chunks: self.tab_snapshot.chunks(input_start..input_end, theme),
 586            input_chunk: Default::default(),
 587            output_position: output_start,
 588            max_output_row: rows.end,
 589            transforms,
 590        }
 591    }
 592
 593    pub fn text_summary(&self) -> TextSummary {
 594        self.transforms.summary().output
 595    }
 596
 597    pub fn max_point(&self) -> WrapPoint {
 598        WrapPoint(self.transforms.summary().output.lines)
 599    }
 600
 601    pub fn line_len(&self, row: u32) -> u32 {
 602        let mut len = 0;
 603        for chunk in self.text_chunks(row) {
 604            if let Some(newline_ix) = chunk.find('\n') {
 605                len += newline_ix;
 606                break;
 607            } else {
 608                len += chunk.len();
 609            }
 610        }
 611        len as u32
 612    }
 613
 614    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 615        let mut cursor = self.transforms.cursor::<WrapPoint>();
 616        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 617        cursor.item().and_then(|transform| {
 618            if transform.is_isomorphic() {
 619                None
 620            } else {
 621                Some(transform.summary.output.lines.column)
 622            }
 623        })
 624    }
 625
 626    pub fn longest_row(&self) -> u32 {
 627        self.transforms.summary().output.longest_row
 628    }
 629
 630    pub fn buffer_rows(&self, start_row: u32) -> WrapBufferRows {
 631        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 632        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 633        let mut input_row = transforms.start().1.row();
 634        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 635            input_row += start_row - transforms.start().0.row();
 636        }
 637        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 638        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 639        let input_buffer_row = input_buffer_rows.next().unwrap();
 640        WrapBufferRows {
 641            transforms,
 642            input_buffer_row,
 643            input_buffer_rows,
 644            output_row: start_row,
 645            soft_wrapped,
 646            max_output_row: self.max_point().row(),
 647        }
 648    }
 649
 650    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 651        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 652        cursor.seek(&point, Bias::Right, &());
 653        let mut tab_point = cursor.start().1 .0;
 654        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 655            tab_point += point.0 - cursor.start().0 .0;
 656        }
 657        TabPoint(tab_point)
 658    }
 659
 660    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 661        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 662    }
 663
 664    pub fn from_point(&self, point: Point, bias: Bias) -> WrapPoint {
 665        self.from_tab_point(self.tab_snapshot.from_point(point, bias))
 666    }
 667
 668    pub fn from_tab_point(&self, point: TabPoint) -> WrapPoint {
 669        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 670        cursor.seek(&point, Bias::Right, &());
 671        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 672    }
 673
 674    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 675        if bias == Bias::Left {
 676            let mut cursor = self.transforms.cursor::<WrapPoint>();
 677            cursor.seek(&point, Bias::Right, &());
 678            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 679                point = *cursor.start();
 680                *point.column_mut() -= 1;
 681            }
 682        }
 683
 684        self.from_tab_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 685    }
 686
 687    fn check_invariants(&self) {
 688        #[cfg(test)]
 689        {
 690            assert_eq!(
 691                TabPoint::from(self.transforms.summary().input.lines),
 692                self.tab_snapshot.max_point()
 693            );
 694
 695            {
 696                let mut transforms = self.transforms.cursor::<()>().peekable();
 697                while let Some(transform) = transforms.next() {
 698                    if let Some(next_transform) = transforms.peek() {
 699                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 700                    }
 701                }
 702            }
 703
 704            let mut expected_buffer_rows = Vec::new();
 705            let mut buffer_row = 0;
 706            let mut prev_tab_row = 0;
 707            for display_row in 0..=self.max_point().row() {
 708                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 709                let soft_wrapped;
 710                if tab_point.row() == prev_tab_row {
 711                    soft_wrapped = display_row != 0;
 712                } else {
 713                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 714                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 715                    buffer_row = buffer_point.row;
 716                    prev_tab_row = tab_point.row();
 717                    soft_wrapped = false;
 718                }
 719                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
 720            }
 721
 722            for start_display_row in 0..expected_buffer_rows.len() {
 723                assert_eq!(
 724                    self.buffer_rows(start_display_row as u32)
 725                        .collect::<Vec<_>>(),
 726                    &expected_buffer_rows[start_display_row..],
 727                    "invalid buffer_rows({}..)",
 728                    start_display_row
 729                );
 730            }
 731        }
 732    }
 733}
 734
 735impl<'a> Iterator for WrapChunks<'a> {
 736    type Item = Chunk<'a>;
 737
 738    fn next(&mut self) -> Option<Self::Item> {
 739        if self.output_position.row() >= self.max_output_row {
 740            return None;
 741        }
 742
 743        let transform = self.transforms.item()?;
 744        if let Some(display_text) = transform.display_text {
 745            let mut start_ix = 0;
 746            let mut end_ix = display_text.len();
 747            let mut summary = transform.summary.output.lines;
 748
 749            if self.output_position > self.transforms.start().0 {
 750                // Exclude newline starting prior to the desired row.
 751                start_ix = 1;
 752                summary.row = 0;
 753            } else if self.output_position.row() + 1 >= self.max_output_row {
 754                // Exclude soft indentation ending after the desired row.
 755                end_ix = 1;
 756                summary.column = 0;
 757            }
 758
 759            self.output_position.0 += summary;
 760            self.transforms.next(&());
 761            return Some(Chunk {
 762                text: &display_text[start_ix..end_ix],
 763                ..self.input_chunk
 764            });
 765        }
 766
 767        if self.input_chunk.text.is_empty() {
 768            self.input_chunk = self.input_chunks.next().unwrap();
 769        }
 770
 771        let mut input_len = 0;
 772        let transform_end = self.transforms.end(&()).0;
 773        for c in self.input_chunk.text.chars() {
 774            let char_len = c.len_utf8();
 775            input_len += char_len;
 776            if c == '\n' {
 777                *self.output_position.row_mut() += 1;
 778                *self.output_position.column_mut() = 0;
 779            } else {
 780                *self.output_position.column_mut() += char_len as u32;
 781            }
 782
 783            if self.output_position >= transform_end {
 784                self.transforms.next(&());
 785                break;
 786            }
 787        }
 788
 789        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 790        self.input_chunk.text = suffix;
 791        Some(Chunk {
 792            text: prefix,
 793            ..self.input_chunk
 794        })
 795    }
 796}
 797
 798impl<'a> Iterator for WrapBufferRows<'a> {
 799    type Item = Option<u32>;
 800
 801    fn next(&mut self) -> Option<Self::Item> {
 802        if self.output_row > self.max_output_row {
 803            return None;
 804        }
 805
 806        let buffer_row = self.input_buffer_row;
 807        let soft_wrapped = self.soft_wrapped;
 808
 809        self.output_row += 1;
 810        self.transforms
 811            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 812        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 813            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 814            self.soft_wrapped = false;
 815        } else {
 816            self.soft_wrapped = true;
 817        }
 818
 819        Some(if soft_wrapped { None } else { Some(buffer_row) })
 820    }
 821}
 822
 823impl Transform {
 824    fn isomorphic(summary: TextSummary) -> Self {
 825        #[cfg(test)]
 826        assert!(!summary.lines.is_zero());
 827
 828        Self {
 829            summary: TransformSummary {
 830                input: summary.clone(),
 831                output: summary,
 832            },
 833            display_text: None,
 834        }
 835    }
 836
 837    fn wrap(indent: u32) -> Self {
 838        lazy_static! {
 839            static ref WRAP_TEXT: String = {
 840                let mut wrap_text = String::new();
 841                wrap_text.push('\n');
 842                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 843                wrap_text
 844            };
 845        }
 846
 847        Self {
 848            summary: TransformSummary {
 849                input: TextSummary::default(),
 850                output: TextSummary {
 851                    lines: Point::new(1, indent),
 852                    first_line_chars: 0,
 853                    last_line_chars: indent,
 854                    longest_row: 1,
 855                    longest_row_chars: indent,
 856                },
 857            },
 858            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 859        }
 860    }
 861
 862    fn is_isomorphic(&self) -> bool {
 863        self.display_text.is_none()
 864    }
 865}
 866
 867impl sum_tree::Item for Transform {
 868    type Summary = TransformSummary;
 869
 870    fn summary(&self) -> Self::Summary {
 871        self.summary.clone()
 872    }
 873}
 874
 875fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 876    if let Some(last_transform) = transforms.last_mut() {
 877        if last_transform.is_isomorphic() {
 878            last_transform.summary.input += &summary;
 879            last_transform.summary.output += &summary;
 880            return;
 881        }
 882    }
 883    transforms.push(Transform::isomorphic(summary));
 884}
 885
 886trait SumTreeExt {
 887    fn push_or_extend(&mut self, transform: Transform);
 888}
 889
 890impl SumTreeExt for SumTree<Transform> {
 891    fn push_or_extend(&mut self, transform: Transform) {
 892        let mut transform = Some(transform);
 893        self.update_last(
 894            |last_transform| {
 895                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 896                    let transform = transform.take().unwrap();
 897                    last_transform.summary.input += &transform.summary.input;
 898                    last_transform.summary.output += &transform.summary.output;
 899                }
 900            },
 901            &(),
 902        );
 903
 904        if let Some(transform) = transform {
 905            self.push(transform, &());
 906        }
 907    }
 908}
 909
 910impl WrapPoint {
 911    pub fn new(row: u32, column: u32) -> Self {
 912        Self(super::Point::new(row, column))
 913    }
 914
 915    pub fn row(self) -> u32 {
 916        self.0.row
 917    }
 918
 919    pub fn row_mut(&mut self) -> &mut u32 {
 920        &mut self.0.row
 921    }
 922
 923    pub fn column(&self) -> u32 {
 924        self.0.column
 925    }
 926
 927    pub fn column_mut(&mut self) -> &mut u32 {
 928        &mut self.0.column
 929    }
 930}
 931
 932impl sum_tree::Summary for TransformSummary {
 933    type Context = ();
 934
 935    fn add_summary(&mut self, other: &Self, _: &()) {
 936        self.input += &other.input;
 937        self.output += &other.output;
 938    }
 939}
 940
 941impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
 942    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 943        self.0 += summary.input.lines;
 944    }
 945}
 946
 947impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
 948    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
 949        Ord::cmp(&self.0, &cursor_location.input.lines)
 950    }
 951}
 952
 953impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
 954    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 955        self.0 += summary.output.lines;
 956    }
 957}
 958
 959fn consolidate_wrap_edits(edits: &mut Vec<WrapEdit>) {
 960    let mut i = 1;
 961    while i < edits.len() {
 962        let edit = edits[i].clone();
 963        let prev_edit = &mut edits[i - 1];
 964        if prev_edit.old.end >= edit.old.start {
 965            prev_edit.old.end = edit.old.end;
 966            prev_edit.new.end = edit.new.end;
 967            edits.remove(i);
 968            continue;
 969        }
 970        i += 1;
 971    }
 972}
 973
 974#[cfg(test)]
 975mod tests {
 976    use super::*;
 977    use crate::{
 978        display_map::{fold_map::FoldMap, tab_map::TabMap},
 979        test::Observer,
 980    };
 981    use language::{multi_buffer::MultiBuffer, RandomCharIter};
 982    use rand::prelude::*;
 983    use std::{cmp, env};
 984    use text::Rope;
 985
 986    #[gpui::test(iterations = 100)]
 987    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
 988        cx.foreground().set_block_on_ticks(0..=50);
 989        cx.foreground().forbid_parking();
 990        let operations = env::var("OPERATIONS")
 991            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
 992            .unwrap_or(10);
 993
 994        let font_cache = cx.font_cache().clone();
 995        let font_system = cx.platform().fonts();
 996        let mut wrap_width = if rng.gen_bool(0.1) {
 997            None
 998        } else {
 999            Some(rng.gen_range(0.0..=1000.0))
1000        };
1001        let tab_size = rng.gen_range(1..=4);
1002        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1003        let font_id = font_cache
1004            .select_font(family_id, &Default::default())
1005            .unwrap();
1006        let font_size = 14.0;
1007
1008        log::info!("Tab size: {}", tab_size);
1009        log::info!("Wrap width: {:?}", wrap_width);
1010
1011        let buffer = cx.update(|cx| {
1012            let len = rng.gen_range(0..10);
1013            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1014            MultiBuffer::build_simple(&text, cx)
1015        });
1016        let buffer_snapshot = buffer.read_with(&cx, |buffer, cx| buffer.snapshot(cx));
1017        let (mut fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1018        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1019        log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1020        log::info!(
1021            "Unwrapped text (unexpanded tabs): {:?}",
1022            folds_snapshot.text()
1023        );
1024        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1025
1026        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1027        let unwrapped_text = tabs_snapshot.text();
1028        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1029
1030        let (wrap_map, _) =
1031            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1032        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
1033
1034        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1035            notifications.recv().await.unwrap();
1036        }
1037
1038        let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1039            assert!(!map.is_rewrapping());
1040            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1041        });
1042
1043        let actual_text = initial_snapshot.text();
1044        assert_eq!(
1045            actual_text, expected_text,
1046            "unwrapped text is: {:?}",
1047            unwrapped_text
1048        );
1049        log::info!("Wrapped text: {:?}", actual_text);
1050
1051        let mut edits = Vec::new();
1052        for _i in 0..operations {
1053            log::info!("{} ==============================================", _i);
1054
1055            let mut buffer_edits = Vec::new();
1056            match rng.gen_range(0..=100) {
1057                0..=19 => {
1058                    wrap_width = if rng.gen_bool(0.2) {
1059                        None
1060                    } else {
1061                        Some(rng.gen_range(0.0..=1000.0))
1062                    };
1063                    log::info!("Setting wrap width to {:?}", wrap_width);
1064                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1065                }
1066                20..=39 => {
1067                    for (folds_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1068                        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1069                        let (mut snapshot, wrap_edits) = wrap_map
1070                            .update(&mut cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1071                        snapshot.check_invariants();
1072                        snapshot.verify_chunks(&mut rng);
1073                        edits.push((snapshot, wrap_edits));
1074                    }
1075                }
1076                _ => {
1077                    buffer.update(&mut cx, |buffer, cx| {
1078                        let subscription = buffer.subscribe();
1079                        let edit_count = rng.gen_range(1..=5);
1080                        buffer.randomly_edit(&mut rng, edit_count, cx);
1081                        buffer_edits.extend(subscription.consume());
1082                    });
1083                }
1084            }
1085
1086            let buffer_snapshot = buffer.read_with(&cx, |buffer, cx| buffer.snapshot(cx));
1087            log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1088            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot, buffer_edits);
1089            log::info!(
1090                "Unwrapped text (unexpanded tabs): {:?}",
1091                folds_snapshot.text()
1092            );
1093            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1094            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1095
1096            let unwrapped_text = tabs_snapshot.text();
1097            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1098            let (mut snapshot, wrap_edits) = wrap_map.update(&mut cx, |map, cx| {
1099                map.sync(tabs_snapshot.clone(), tab_edits, cx)
1100            });
1101            snapshot.check_invariants();
1102            snapshot.verify_chunks(&mut rng);
1103            edits.push((snapshot, wrap_edits));
1104
1105            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1106                log::info!("Waiting for wrapping to finish");
1107                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1108                    notifications.recv().await.unwrap();
1109                }
1110                wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1111            }
1112
1113            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1114                let (mut wrapped_snapshot, wrap_edits) =
1115                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1116                let actual_text = wrapped_snapshot.text();
1117                let actual_longest_row = wrapped_snapshot.longest_row();
1118                log::info!("Wrapping finished: {:?}", actual_text);
1119                wrapped_snapshot.check_invariants();
1120                wrapped_snapshot.verify_chunks(&mut rng);
1121                edits.push((wrapped_snapshot.clone(), wrap_edits));
1122                assert_eq!(
1123                    actual_text, expected_text,
1124                    "unwrapped text is: {:?}",
1125                    unwrapped_text
1126                );
1127
1128                let mut summary = TextSummary::default();
1129                for (ix, item) in wrapped_snapshot
1130                    .transforms
1131                    .items(&())
1132                    .into_iter()
1133                    .enumerate()
1134                {
1135                    summary += &item.summary.output;
1136                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1137                }
1138
1139                if tab_size == 1
1140                    || !wrapped_snapshot
1141                        .tab_snapshot
1142                        .fold_snapshot
1143                        .text()
1144                        .contains('\t')
1145                {
1146                    let mut expected_longest_rows = Vec::new();
1147                    let mut longest_line_len = -1;
1148                    for (row, line) in expected_text.split('\n').enumerate() {
1149                        let line_char_count = line.chars().count() as isize;
1150                        if line_char_count > longest_line_len {
1151                            expected_longest_rows.clear();
1152                            longest_line_len = line_char_count;
1153                        }
1154                        if line_char_count >= longest_line_len {
1155                            expected_longest_rows.push(row as u32);
1156                        }
1157                    }
1158
1159                    assert!(
1160                        expected_longest_rows.contains(&actual_longest_row),
1161                        "incorrect longest row {}. expected {:?} with length {}",
1162                        actual_longest_row,
1163                        expected_longest_rows,
1164                        longest_line_len,
1165                    )
1166                }
1167            }
1168        }
1169
1170        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1171        for (snapshot, patch) in edits {
1172            let snapshot_text = Rope::from(snapshot.text().as_str());
1173            for edit in &patch {
1174                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1175                let old_end = initial_text.point_to_offset(cmp::min(
1176                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1177                    initial_text.max_point(),
1178                ));
1179                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1180                let new_end = snapshot_text.point_to_offset(cmp::min(
1181                    Point::new(edit.new.end, 0),
1182                    snapshot_text.max_point(),
1183                ));
1184                let new_text = snapshot_text
1185                    .chunks_in_range(new_start..new_end)
1186                    .collect::<String>();
1187
1188                initial_text.replace(old_start..old_end, &new_text);
1189            }
1190            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1191        }
1192
1193        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1194            log::info!("Waiting for wrapping to finish");
1195            while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1196                notifications.recv().await.unwrap();
1197            }
1198        }
1199        wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1200    }
1201
1202    fn wrap_text(
1203        unwrapped_text: &str,
1204        wrap_width: Option<f32>,
1205        line_wrapper: &mut LineWrapper,
1206    ) -> String {
1207        if let Some(wrap_width) = wrap_width {
1208            let mut wrapped_text = String::new();
1209            for (row, line) in unwrapped_text.split('\n').enumerate() {
1210                if row > 0 {
1211                    wrapped_text.push('\n')
1212                }
1213
1214                let mut prev_ix = 0;
1215                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1216                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1217                    wrapped_text.push('\n');
1218                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1219                    prev_ix = boundary.ix;
1220                }
1221                wrapped_text.push_str(&line[prev_ix..]);
1222            }
1223            wrapped_text
1224        } else {
1225            unwrapped_text.to_string()
1226        }
1227    }
1228
1229    impl WrapSnapshot {
1230        pub fn text(&self) -> String {
1231            self.text_chunks(0).collect()
1232        }
1233
1234        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1235            for _ in 0..5 {
1236                let mut end_row = rng.gen_range(0..=self.max_point().row());
1237                let start_row = rng.gen_range(0..=end_row);
1238                end_row += 1;
1239
1240                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1241                if expected_text.ends_with("\n") {
1242                    expected_text.push('\n');
1243                }
1244                let mut expected_text = expected_text
1245                    .lines()
1246                    .take((end_row - start_row) as usize)
1247                    .collect::<Vec<_>>()
1248                    .join("\n");
1249                if end_row <= self.max_point().row() {
1250                    expected_text.push('\n');
1251                }
1252
1253                let actual_text = self
1254                    .chunks(start_row..end_row, None)
1255                    .map(|c| c.text)
1256                    .collect::<String>();
1257                assert_eq!(
1258                    expected_text,
1259                    actual_text,
1260                    "chunks != highlighted_chunks for rows {:?}",
1261                    start_row..end_row
1262                );
1263            }
1264        }
1265    }
1266}