1use super::{
   2    Highlights,
   3    fold_map::{Chunk, FoldRows},
   4    tab_map::{self, TabEdit, TabPoint, TabSnapshot},
   5};
   6use gpui::{App, AppContext as _, Context, Entity, Font, LineWrapper, Pixels, Task};
   7use language::Point;
   8use multi_buffer::{MultiBufferSnapshot, RowInfo};
   9use smol::future::yield_now;
  10use std::sync::LazyLock;
  11use std::{cmp, collections::VecDeque, mem, ops::Range, time::Duration};
  12use sum_tree::{Bias, Cursor, SumTree};
  13use text::Patch;
  14
  15pub use super::tab_map::TextSummary;
  16pub type WrapEdit = text::Edit<u32>;
  17
  18/// Handles soft wrapping of text.
  19///
  20/// See the [`display_map` module documentation](crate::display_map) for more information.
  21pub struct WrapMap {
  22    snapshot: WrapSnapshot,
  23    pending_edits: VecDeque<(TabSnapshot, Vec<TabEdit>)>,
  24    interpolated_edits: Patch<u32>,
  25    edits_since_sync: Patch<u32>,
  26    wrap_width: Option<Pixels>,
  27    background_task: Option<Task<()>>,
  28    font_with_size: (Font, Pixels),
  29}
  30
  31#[derive(Clone)]
  32pub struct WrapSnapshot {
  33    tab_snapshot: TabSnapshot,
  34    transforms: SumTree<Transform>,
  35    interpolated: bool,
  36}
  37
  38#[derive(Clone, Debug, Default, Eq, PartialEq)]
  39struct Transform {
  40    summary: TransformSummary,
  41    display_text: Option<&'static str>,
  42}
  43
  44#[derive(Clone, Debug, Default, Eq, PartialEq)]
  45struct TransformSummary {
  46    input: TextSummary,
  47    output: TextSummary,
  48}
  49
  50#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  51pub struct WrapPoint(pub Point);
  52
  53pub struct WrapChunks<'a> {
  54    input_chunks: tab_map::TabChunks<'a>,
  55    input_chunk: Chunk<'a>,
  56    output_position: WrapPoint,
  57    max_output_row: u32,
  58    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  59    snapshot: &'a WrapSnapshot,
  60}
  61
  62#[derive(Clone)]
  63pub struct WrapRows<'a> {
  64    input_buffer_rows: FoldRows<'a>,
  65    input_buffer_row: RowInfo,
  66    output_row: u32,
  67    soft_wrapped: bool,
  68    max_output_row: u32,
  69    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  70}
  71
  72impl WrapRows<'_> {
  73    pub(crate) fn seek(&mut self, start_row: u32) {
  74        self.transforms
  75            .seek(&WrapPoint::new(start_row, 0), Bias::Left);
  76        let mut input_row = self.transforms.start().1.row();
  77        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
  78            input_row += start_row - self.transforms.start().0.row();
  79        }
  80        self.soft_wrapped = self.transforms.item().map_or(false, |t| !t.is_isomorphic());
  81        self.input_buffer_rows.seek(input_row);
  82        self.input_buffer_row = self.input_buffer_rows.next().unwrap();
  83        self.output_row = start_row;
  84    }
  85}
  86
  87impl WrapMap {
  88    pub fn new(
  89        tab_snapshot: TabSnapshot,
  90        font: Font,
  91        font_size: Pixels,
  92        wrap_width: Option<Pixels>,
  93        cx: &mut App,
  94    ) -> (Entity<Self>, WrapSnapshot) {
  95        let handle = cx.new(|cx| {
  96            let mut this = Self {
  97                font_with_size: (font, font_size),
  98                wrap_width: None,
  99                pending_edits: Default::default(),
 100                interpolated_edits: Default::default(),
 101                edits_since_sync: Default::default(),
 102                snapshot: WrapSnapshot::new(tab_snapshot),
 103                background_task: None,
 104            };
 105            this.set_wrap_width(wrap_width, cx);
 106            mem::take(&mut this.edits_since_sync);
 107            this
 108        });
 109        let snapshot = handle.read(cx).snapshot.clone();
 110        (handle, snapshot)
 111    }
 112
 113    #[cfg(test)]
 114    pub fn is_rewrapping(&self) -> bool {
 115        self.background_task.is_some()
 116    }
 117
 118    pub fn sync(
 119        &mut self,
 120        tab_snapshot: TabSnapshot,
 121        edits: Vec<TabEdit>,
 122        cx: &mut Context<Self>,
 123    ) -> (WrapSnapshot, Patch<u32>) {
 124        if self.wrap_width.is_some() {
 125            self.pending_edits.push_back((tab_snapshot, edits));
 126            self.flush_edits(cx);
 127        } else {
 128            self.edits_since_sync = self
 129                .edits_since_sync
 130                .compose(self.snapshot.interpolate(tab_snapshot, &edits));
 131            self.snapshot.interpolated = false;
 132        }
 133
 134        (self.snapshot.clone(), mem::take(&mut self.edits_since_sync))
 135    }
 136
 137    pub fn set_font_with_size(
 138        &mut self,
 139        font: Font,
 140        font_size: Pixels,
 141        cx: &mut Context<Self>,
 142    ) -> bool {
 143        let font_with_size = (font, font_size);
 144
 145        if font_with_size == self.font_with_size {
 146            false
 147        } else {
 148            self.font_with_size = font_with_size;
 149            self.rewrap(cx);
 150            true
 151        }
 152    }
 153
 154    pub fn set_wrap_width(&mut self, wrap_width: Option<Pixels>, cx: &mut Context<Self>) -> bool {
 155        if wrap_width == self.wrap_width {
 156            return false;
 157        }
 158
 159        self.wrap_width = wrap_width;
 160        self.rewrap(cx);
 161        true
 162    }
 163
 164    fn rewrap(&mut self, cx: &mut Context<Self>) {
 165        self.background_task.take();
 166        self.interpolated_edits.clear();
 167        self.pending_edits.clear();
 168
 169        if let Some(wrap_width) = self.wrap_width {
 170            let mut new_snapshot = self.snapshot.clone();
 171
 172            let text_system = cx.text_system().clone();
 173            let (font, font_size) = self.font_with_size.clone();
 174            let task = cx.background_spawn(async move {
 175                let mut line_wrapper = text_system.line_wrapper(font, font_size);
 176                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 177                let range = TabPoint::zero()..tab_snapshot.max_point();
 178                let edits = new_snapshot
 179                    .update(
 180                        tab_snapshot,
 181                        &[TabEdit {
 182                            old: range.clone(),
 183                            new: range.clone(),
 184                        }],
 185                        wrap_width,
 186                        &mut line_wrapper,
 187                    )
 188                    .await;
 189                (new_snapshot, edits)
 190            });
 191
 192            match cx
 193                .background_executor()
 194                .block_with_timeout(Duration::from_millis(5), task)
 195            {
 196                Ok((snapshot, edits)) => {
 197                    self.snapshot = snapshot;
 198                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 199                }
 200                Err(wrap_task) => {
 201                    self.background_task = Some(cx.spawn(async move |this, cx| {
 202                        let (snapshot, edits) = wrap_task.await;
 203                        this.update(cx, |this, cx| {
 204                            this.snapshot = snapshot;
 205                            this.edits_since_sync = this
 206                                .edits_since_sync
 207                                .compose(mem::take(&mut this.interpolated_edits).invert())
 208                                .compose(&edits);
 209                            this.background_task = None;
 210                            this.flush_edits(cx);
 211                            cx.notify();
 212                        })
 213                        .ok();
 214                    }));
 215                }
 216            }
 217        } else {
 218            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 219            self.snapshot.transforms = SumTree::default();
 220            let summary = self.snapshot.tab_snapshot.text_summary();
 221            if !summary.lines.is_zero() {
 222                self.snapshot
 223                    .transforms
 224                    .push(Transform::isomorphic(summary), &());
 225            }
 226            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 227            self.snapshot.interpolated = false;
 228            self.edits_since_sync = self.edits_since_sync.compose(Patch::new(vec![WrapEdit {
 229                old: 0..old_rows,
 230                new: 0..new_rows,
 231            }]));
 232        }
 233    }
 234
 235    fn flush_edits(&mut self, cx: &mut Context<Self>) {
 236        if !self.snapshot.interpolated {
 237            let mut to_remove_len = 0;
 238            for (tab_snapshot, _) in &self.pending_edits {
 239                if tab_snapshot.version <= self.snapshot.tab_snapshot.version {
 240                    to_remove_len += 1;
 241                } else {
 242                    break;
 243                }
 244            }
 245            self.pending_edits.drain(..to_remove_len);
 246        }
 247
 248        if self.pending_edits.is_empty() {
 249            return;
 250        }
 251
 252        if let Some(wrap_width) = self.wrap_width {
 253            if self.background_task.is_none() {
 254                let pending_edits = self.pending_edits.clone();
 255                let mut snapshot = self.snapshot.clone();
 256                let text_system = cx.text_system().clone();
 257                let (font, font_size) = self.font_with_size.clone();
 258                let update_task = cx.background_spawn(async move {
 259                    let mut edits = Patch::default();
 260                    let mut line_wrapper = text_system.line_wrapper(font, font_size);
 261                    for (tab_snapshot, tab_edits) in pending_edits {
 262                        let wrap_edits = snapshot
 263                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 264                            .await;
 265                        edits = edits.compose(&wrap_edits);
 266                    }
 267                    (snapshot, edits)
 268                });
 269
 270                match cx
 271                    .background_executor()
 272                    .block_with_timeout(Duration::from_millis(1), update_task)
 273                {
 274                    Ok((snapshot, output_edits)) => {
 275                        self.snapshot = snapshot;
 276                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 277                    }
 278                    Err(update_task) => {
 279                        self.background_task = Some(cx.spawn(async move |this, cx| {
 280                            let (snapshot, edits) = update_task.await;
 281                            this.update(cx, |this, cx| {
 282                                this.snapshot = snapshot;
 283                                this.edits_since_sync = this
 284                                    .edits_since_sync
 285                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 286                                    .compose(&edits);
 287                                this.background_task = None;
 288                                this.flush_edits(cx);
 289                                cx.notify();
 290                            })
 291                            .ok();
 292                        }));
 293                    }
 294                }
 295            }
 296        }
 297
 298        let was_interpolated = self.snapshot.interpolated;
 299        let mut to_remove_len = 0;
 300        for (tab_snapshot, edits) in &self.pending_edits {
 301            if tab_snapshot.version <= self.snapshot.tab_snapshot.version {
 302                to_remove_len += 1;
 303            } else {
 304                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), edits);
 305                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 306                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 307            }
 308        }
 309
 310        if !was_interpolated {
 311            self.pending_edits.drain(..to_remove_len);
 312        }
 313    }
 314}
 315
 316impl WrapSnapshot {
 317    fn new(tab_snapshot: TabSnapshot) -> Self {
 318        let mut transforms = SumTree::default();
 319        let extent = tab_snapshot.text_summary();
 320        if !extent.lines.is_zero() {
 321            transforms.push(Transform::isomorphic(extent), &());
 322        }
 323        Self {
 324            transforms,
 325            tab_snapshot,
 326            interpolated: true,
 327        }
 328    }
 329
 330    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 331        self.tab_snapshot.buffer_snapshot()
 332    }
 333
 334    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 335        let mut new_transforms;
 336        if tab_edits.is_empty() {
 337            new_transforms = self.transforms.clone();
 338        } else {
 339            let mut old_cursor = self.transforms.cursor::<TabPoint>(&());
 340
 341            let mut tab_edits_iter = tab_edits.iter().peekable();
 342            new_transforms =
 343                old_cursor.slice(&tab_edits_iter.peek().unwrap().old.start, Bias::Right);
 344
 345            while let Some(edit) = tab_edits_iter.next() {
 346                if edit.new.start > TabPoint::from(new_transforms.summary().input.lines) {
 347                    let summary = new_tab_snapshot.text_summary_for_range(
 348                        TabPoint::from(new_transforms.summary().input.lines)..edit.new.start,
 349                    );
 350                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 351                }
 352
 353                if !edit.new.is_empty() {
 354                    new_transforms.push_or_extend(Transform::isomorphic(
 355                        new_tab_snapshot.text_summary_for_range(edit.new.clone()),
 356                    ));
 357                }
 358
 359                old_cursor.seek_forward(&edit.old.end, Bias::Right);
 360                if let Some(next_edit) = tab_edits_iter.peek() {
 361                    if next_edit.old.start > old_cursor.end() {
 362                        if old_cursor.end() > edit.old.end {
 363                            let summary = self
 364                                .tab_snapshot
 365                                .text_summary_for_range(edit.old.end..old_cursor.end());
 366                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 367                        }
 368
 369                        old_cursor.next();
 370                        new_transforms
 371                            .append(old_cursor.slice(&next_edit.old.start, Bias::Right), &());
 372                    }
 373                } else {
 374                    if old_cursor.end() > edit.old.end {
 375                        let summary = self
 376                            .tab_snapshot
 377                            .text_summary_for_range(edit.old.end..old_cursor.end());
 378                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 379                    }
 380                    old_cursor.next();
 381                    new_transforms.append(old_cursor.suffix(), &());
 382                }
 383            }
 384        }
 385
 386        let old_snapshot = mem::replace(
 387            self,
 388            WrapSnapshot {
 389                tab_snapshot: new_tab_snapshot,
 390                transforms: new_transforms,
 391                interpolated: true,
 392            },
 393        );
 394        self.check_invariants();
 395        old_snapshot.compute_edits(tab_edits, self)
 396    }
 397
 398    async fn update(
 399        &mut self,
 400        new_tab_snapshot: TabSnapshot,
 401        tab_edits: &[TabEdit],
 402        wrap_width: Pixels,
 403        line_wrapper: &mut LineWrapper,
 404    ) -> Patch<u32> {
 405        #[derive(Debug)]
 406        struct RowEdit {
 407            old_rows: Range<u32>,
 408            new_rows: Range<u32>,
 409        }
 410
 411        let mut tab_edits_iter = tab_edits.iter().peekable();
 412        let mut row_edits = Vec::with_capacity(tab_edits.len());
 413        while let Some(edit) = tab_edits_iter.next() {
 414            let mut row_edit = RowEdit {
 415                old_rows: edit.old.start.row()..edit.old.end.row() + 1,
 416                new_rows: edit.new.start.row()..edit.new.end.row() + 1,
 417            };
 418
 419            while let Some(next_edit) = tab_edits_iter.peek() {
 420                if next_edit.old.start.row() <= row_edit.old_rows.end {
 421                    row_edit.old_rows.end = next_edit.old.end.row() + 1;
 422                    row_edit.new_rows.end = next_edit.new.end.row() + 1;
 423                    tab_edits_iter.next();
 424                } else {
 425                    break;
 426                }
 427            }
 428
 429            row_edits.push(row_edit);
 430        }
 431
 432        let mut new_transforms;
 433        if row_edits.is_empty() {
 434            new_transforms = self.transforms.clone();
 435        } else {
 436            let mut row_edits = row_edits.into_iter().peekable();
 437            let mut old_cursor = self.transforms.cursor::<TabPoint>(&());
 438
 439            new_transforms = old_cursor.slice(
 440                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 441                Bias::Right,
 442            );
 443
 444            while let Some(edit) = row_edits.next() {
 445                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 446                    let summary = new_tab_snapshot.text_summary_for_range(
 447                        TabPoint(new_transforms.summary().input.lines)
 448                            ..TabPoint::new(edit.new_rows.start, 0),
 449                    );
 450                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 451                }
 452
 453                let mut line = String::new();
 454                let mut line_fragments = Vec::new();
 455                let mut remaining = None;
 456                let mut chunks = new_tab_snapshot.chunks(
 457                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 458                    false,
 459                    Highlights::default(),
 460                );
 461                let mut edit_transforms = Vec::<Transform>::new();
 462                for _ in edit.new_rows.start..edit.new_rows.end {
 463                    while let Some(chunk) = remaining.take().or_else(|| chunks.next()) {
 464                        if let Some(ix) = chunk.text.find('\n') {
 465                            let (prefix, suffix) = chunk.text.split_at(ix + 1);
 466                            line_fragments.push(gpui::LineFragment::text(prefix));
 467                            line.push_str(prefix);
 468                            remaining = Some(Chunk {
 469                                text: suffix,
 470                                ..chunk
 471                            });
 472                            break;
 473                        } else {
 474                            if let Some(width) =
 475                                chunk.renderer.as_ref().and_then(|r| r.measured_width)
 476                            {
 477                                line_fragments
 478                                    .push(gpui::LineFragment::element(width, chunk.text.len()));
 479                            } else {
 480                                line_fragments.push(gpui::LineFragment::text(chunk.text));
 481                            }
 482                            line.push_str(chunk.text);
 483                        }
 484                    }
 485
 486                    if line.is_empty() {
 487                        break;
 488                    }
 489
 490                    let mut prev_boundary_ix = 0;
 491                    for boundary in line_wrapper.wrap_line(&line_fragments, wrap_width) {
 492                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 493                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 494                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 495                        prev_boundary_ix = boundary.ix;
 496                    }
 497
 498                    if prev_boundary_ix < line.len() {
 499                        push_isomorphic(
 500                            &mut edit_transforms,
 501                            TextSummary::from(&line[prev_boundary_ix..]),
 502                        );
 503                    }
 504
 505                    line.clear();
 506                    line_fragments.clear();
 507                    yield_now().await;
 508                }
 509
 510                let mut edit_transforms = edit_transforms.into_iter();
 511                if let Some(transform) = edit_transforms.next() {
 512                    new_transforms.push_or_extend(transform);
 513                }
 514                new_transforms.extend(edit_transforms, &());
 515
 516                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right);
 517                if let Some(next_edit) = row_edits.peek() {
 518                    if next_edit.old_rows.start > old_cursor.end().row() {
 519                        if old_cursor.end() > TabPoint::new(edit.old_rows.end, 0) {
 520                            let summary = self.tab_snapshot.text_summary_for_range(
 521                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(),
 522                            );
 523                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 524                        }
 525                        old_cursor.next();
 526                        new_transforms.append(
 527                            old_cursor
 528                                .slice(&TabPoint::new(next_edit.old_rows.start, 0), Bias::Right),
 529                            &(),
 530                        );
 531                    }
 532                } else {
 533                    if old_cursor.end() > TabPoint::new(edit.old_rows.end, 0) {
 534                        let summary = self.tab_snapshot.text_summary_for_range(
 535                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(),
 536                        );
 537                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 538                    }
 539                    old_cursor.next();
 540                    new_transforms.append(old_cursor.suffix(), &());
 541                }
 542            }
 543        }
 544
 545        let old_snapshot = mem::replace(
 546            self,
 547            WrapSnapshot {
 548                tab_snapshot: new_tab_snapshot,
 549                transforms: new_transforms,
 550                interpolated: false,
 551            },
 552        );
 553        self.check_invariants();
 554        old_snapshot.compute_edits(tab_edits, self)
 555    }
 556
 557    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &WrapSnapshot) -> Patch<u32> {
 558        let mut wrap_edits = Vec::with_capacity(tab_edits.len());
 559        let mut old_cursor = self.transforms.cursor::<TransformSummary>(&());
 560        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>(&());
 561        for mut tab_edit in tab_edits.iter().cloned() {
 562            tab_edit.old.start.0.column = 0;
 563            tab_edit.old.end.0 += Point::new(1, 0);
 564            tab_edit.new.start.0.column = 0;
 565            tab_edit.new.end.0 += Point::new(1, 0);
 566
 567            old_cursor.seek(&tab_edit.old.start, Bias::Right);
 568            let mut old_start = old_cursor.start().output.lines;
 569            old_start += tab_edit.old.start.0 - old_cursor.start().input.lines;
 570
 571            old_cursor.seek(&tab_edit.old.end, Bias::Right);
 572            let mut old_end = old_cursor.start().output.lines;
 573            old_end += tab_edit.old.end.0 - old_cursor.start().input.lines;
 574
 575            new_cursor.seek(&tab_edit.new.start, Bias::Right);
 576            let mut new_start = new_cursor.start().output.lines;
 577            new_start += tab_edit.new.start.0 - new_cursor.start().input.lines;
 578
 579            new_cursor.seek(&tab_edit.new.end, Bias::Right);
 580            let mut new_end = new_cursor.start().output.lines;
 581            new_end += tab_edit.new.end.0 - new_cursor.start().input.lines;
 582
 583            wrap_edits.push(WrapEdit {
 584                old: old_start.row..old_end.row,
 585                new: new_start.row..new_end.row,
 586            });
 587        }
 588
 589        wrap_edits = consolidate_wrap_edits(wrap_edits);
 590        Patch::new(wrap_edits)
 591    }
 592
 593    pub(crate) fn chunks<'a>(
 594        &'a self,
 595        rows: Range<u32>,
 596        language_aware: bool,
 597        highlights: Highlights<'a>,
 598    ) -> WrapChunks<'a> {
 599        let output_start = WrapPoint::new(rows.start, 0);
 600        let output_end = WrapPoint::new(rows.end, 0);
 601        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 602        transforms.seek(&output_start, Bias::Right);
 603        let mut input_start = TabPoint(transforms.start().1.0);
 604        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 605            input_start.0 += output_start.0 - transforms.start().0.0;
 606        }
 607        let input_end = self
 608            .to_tab_point(output_end)
 609            .min(self.tab_snapshot.max_point());
 610        WrapChunks {
 611            input_chunks: self.tab_snapshot.chunks(
 612                input_start..input_end,
 613                language_aware,
 614                highlights,
 615            ),
 616            input_chunk: Default::default(),
 617            output_position: output_start,
 618            max_output_row: rows.end,
 619            transforms,
 620            snapshot: self,
 621        }
 622    }
 623
 624    pub fn max_point(&self) -> WrapPoint {
 625        WrapPoint(self.transforms.summary().output.lines)
 626    }
 627
 628    pub fn line_len(&self, row: u32) -> u32 {
 629        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 630        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Left);
 631        if cursor
 632            .item()
 633            .map_or(false, |transform| transform.is_isomorphic())
 634        {
 635            let overshoot = row - cursor.start().0.row();
 636            let tab_row = cursor.start().1.row() + overshoot;
 637            let tab_line_len = self.tab_snapshot.line_len(tab_row);
 638            if overshoot == 0 {
 639                cursor.start().0.column() + (tab_line_len - cursor.start().1.column())
 640            } else {
 641                tab_line_len
 642            }
 643        } else {
 644            cursor.start().0.column()
 645        }
 646    }
 647
 648    pub fn text_summary_for_range(&self, rows: Range<u32>) -> TextSummary {
 649        let mut summary = TextSummary::default();
 650
 651        let start = WrapPoint::new(rows.start, 0);
 652        let end = WrapPoint::new(rows.end, 0);
 653
 654        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 655        cursor.seek(&start, Bias::Right);
 656        if let Some(transform) = cursor.item() {
 657            let start_in_transform = start.0 - cursor.start().0.0;
 658            let end_in_transform = cmp::min(end, cursor.end().0).0 - cursor.start().0.0;
 659            if transform.is_isomorphic() {
 660                let tab_start = TabPoint(cursor.start().1.0 + start_in_transform);
 661                let tab_end = TabPoint(cursor.start().1.0 + end_in_transform);
 662                summary += &self.tab_snapshot.text_summary_for_range(tab_start..tab_end);
 663            } else {
 664                debug_assert_eq!(start_in_transform.row, end_in_transform.row);
 665                let indent_len = end_in_transform.column - start_in_transform.column;
 666                summary += &TextSummary {
 667                    lines: Point::new(0, indent_len),
 668                    first_line_chars: indent_len,
 669                    last_line_chars: indent_len,
 670                    longest_row: 0,
 671                    longest_row_chars: indent_len,
 672                };
 673            }
 674
 675            cursor.next();
 676        }
 677
 678        if rows.end > cursor.start().0.row() {
 679            summary += &cursor
 680                .summary::<_, TransformSummary>(&WrapPoint::new(rows.end, 0), Bias::Right)
 681                .output;
 682
 683            if let Some(transform) = cursor.item() {
 684                let end_in_transform = end.0 - cursor.start().0.0;
 685                if transform.is_isomorphic() {
 686                    let char_start = cursor.start().1;
 687                    let char_end = TabPoint(char_start.0 + end_in_transform);
 688                    summary += &self
 689                        .tab_snapshot
 690                        .text_summary_for_range(char_start..char_end);
 691                } else {
 692                    debug_assert_eq!(end_in_transform, Point::new(1, 0));
 693                    summary += &TextSummary {
 694                        lines: Point::new(1, 0),
 695                        first_line_chars: 0,
 696                        last_line_chars: 0,
 697                        longest_row: 0,
 698                        longest_row_chars: 0,
 699                    };
 700                }
 701            }
 702        }
 703
 704        summary
 705    }
 706
 707    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 708        let mut cursor = self.transforms.cursor::<WrapPoint>(&());
 709        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right);
 710        cursor.item().and_then(|transform| {
 711            if transform.is_isomorphic() {
 712                None
 713            } else {
 714                Some(transform.summary.output.lines.column)
 715            }
 716        })
 717    }
 718
 719    pub fn longest_row(&self) -> u32 {
 720        self.transforms.summary().output.longest_row
 721    }
 722
 723    pub fn row_infos(&self, start_row: u32) -> WrapRows<'_> {
 724        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 725        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left);
 726        let mut input_row = transforms.start().1.row();
 727        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 728            input_row += start_row - transforms.start().0.row();
 729        }
 730        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 731        let mut input_buffer_rows = self.tab_snapshot.rows(input_row);
 732        let input_buffer_row = input_buffer_rows.next().unwrap();
 733        WrapRows {
 734            transforms,
 735            input_buffer_row,
 736            input_buffer_rows,
 737            output_row: start_row,
 738            soft_wrapped,
 739            max_output_row: self.max_point().row(),
 740        }
 741    }
 742
 743    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 744        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 745        cursor.seek(&point, Bias::Right);
 746        let mut tab_point = cursor.start().1.0;
 747        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 748            tab_point += point.0 - cursor.start().0.0;
 749        }
 750        TabPoint(tab_point)
 751    }
 752
 753    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 754        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 755    }
 756
 757    pub fn make_wrap_point(&self, point: Point, bias: Bias) -> WrapPoint {
 758        self.tab_point_to_wrap_point(self.tab_snapshot.make_tab_point(point, bias))
 759    }
 760
 761    pub fn tab_point_to_wrap_point(&self, point: TabPoint) -> WrapPoint {
 762        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>(&());
 763        cursor.seek(&point, Bias::Right);
 764        WrapPoint(cursor.start().1.0 + (point.0 - cursor.start().0.0))
 765    }
 766
 767    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 768        if bias == Bias::Left {
 769            let mut cursor = self.transforms.cursor::<WrapPoint>(&());
 770            cursor.seek(&point, Bias::Right);
 771            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 772                point = *cursor.start();
 773                *point.column_mut() -= 1;
 774            }
 775        }
 776
 777        self.tab_point_to_wrap_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 778    }
 779
 780    pub fn prev_row_boundary(&self, mut point: WrapPoint) -> u32 {
 781        if self.transforms.is_empty() {
 782            return 0;
 783        }
 784
 785        *point.column_mut() = 0;
 786
 787        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 788        cursor.seek(&point, Bias::Right);
 789        if cursor.item().is_none() {
 790            cursor.prev();
 791        }
 792
 793        while let Some(transform) = cursor.item() {
 794            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 795                return cmp::min(cursor.end().0.row(), point.row());
 796            } else {
 797                cursor.prev();
 798            }
 799        }
 800
 801        unreachable!()
 802    }
 803
 804    pub fn next_row_boundary(&self, mut point: WrapPoint) -> Option<u32> {
 805        point.0 += Point::new(1, 0);
 806
 807        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>(&());
 808        cursor.seek(&point, Bias::Right);
 809        while let Some(transform) = cursor.item() {
 810            if transform.is_isomorphic() && cursor.start().1.column() == 0 {
 811                return Some(cmp::max(cursor.start().0.row(), point.row()));
 812            } else {
 813                cursor.next();
 814            }
 815        }
 816
 817        None
 818    }
 819
 820    #[cfg(test)]
 821    pub fn text(&self) -> String {
 822        self.text_chunks(0).collect()
 823    }
 824
 825    #[cfg(test)]
 826    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 827        self.chunks(
 828            wrap_row..self.max_point().row() + 1,
 829            false,
 830            Highlights::default(),
 831        )
 832        .map(|h| h.text)
 833    }
 834
 835    fn check_invariants(&self) {
 836        #[cfg(test)]
 837        {
 838            assert_eq!(
 839                TabPoint::from(self.transforms.summary().input.lines),
 840                self.tab_snapshot.max_point()
 841            );
 842
 843            {
 844                let mut transforms = self.transforms.cursor::<()>(&()).peekable();
 845                while let Some(transform) = transforms.next() {
 846                    if let Some(next_transform) = transforms.peek() {
 847                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 848                    }
 849                }
 850            }
 851
 852            let text = language::Rope::from(self.text().as_str());
 853            let mut input_buffer_rows = self.tab_snapshot.rows(0);
 854            let mut expected_buffer_rows = Vec::new();
 855            let mut prev_tab_row = 0;
 856            for display_row in 0..=self.max_point().row() {
 857                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 858                if tab_point.row() == prev_tab_row && display_row != 0 {
 859                    expected_buffer_rows.push(None);
 860                } else {
 861                    expected_buffer_rows.push(input_buffer_rows.next().unwrap().buffer_row);
 862                }
 863
 864                prev_tab_row = tab_point.row();
 865                assert_eq!(self.line_len(display_row), text.line_len(display_row));
 866            }
 867
 868            for start_display_row in 0..expected_buffer_rows.len() {
 869                assert_eq!(
 870                    self.row_infos(start_display_row as u32)
 871                        .map(|row_info| row_info.buffer_row)
 872                        .collect::<Vec<_>>(),
 873                    &expected_buffer_rows[start_display_row..],
 874                    "invalid buffer_rows({}..)",
 875                    start_display_row
 876                );
 877            }
 878        }
 879    }
 880}
 881
 882impl WrapChunks<'_> {
 883    pub(crate) fn seek(&mut self, rows: Range<u32>) {
 884        let output_start = WrapPoint::new(rows.start, 0);
 885        let output_end = WrapPoint::new(rows.end, 0);
 886        self.transforms.seek(&output_start, Bias::Right);
 887        let mut input_start = TabPoint(self.transforms.start().1.0);
 888        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 889            input_start.0 += output_start.0 - self.transforms.start().0.0;
 890        }
 891        let input_end = self
 892            .snapshot
 893            .to_tab_point(output_end)
 894            .min(self.snapshot.tab_snapshot.max_point());
 895        self.input_chunks.seek(input_start..input_end);
 896        self.input_chunk = Chunk::default();
 897        self.output_position = output_start;
 898        self.max_output_row = rows.end;
 899    }
 900}
 901
 902impl<'a> Iterator for WrapChunks<'a> {
 903    type Item = Chunk<'a>;
 904
 905    fn next(&mut self) -> Option<Self::Item> {
 906        if self.output_position.row() >= self.max_output_row {
 907            return None;
 908        }
 909
 910        let transform = self.transforms.item()?;
 911        if let Some(display_text) = transform.display_text {
 912            let mut start_ix = 0;
 913            let mut end_ix = display_text.len();
 914            let mut summary = transform.summary.output.lines;
 915
 916            if self.output_position > self.transforms.start().0 {
 917                // Exclude newline starting prior to the desired row.
 918                start_ix = 1;
 919                summary.row = 0;
 920            } else if self.output_position.row() + 1 >= self.max_output_row {
 921                // Exclude soft indentation ending after the desired row.
 922                end_ix = 1;
 923                summary.column = 0;
 924            }
 925
 926            self.output_position.0 += summary;
 927            self.transforms.next();
 928            return Some(Chunk {
 929                text: &display_text[start_ix..end_ix],
 930                ..Default::default()
 931            });
 932        }
 933
 934        if self.input_chunk.text.is_empty() {
 935            self.input_chunk = self.input_chunks.next().unwrap();
 936        }
 937
 938        let mut input_len = 0;
 939        let transform_end = self.transforms.end().0;
 940        for c in self.input_chunk.text.chars() {
 941            let char_len = c.len_utf8();
 942            input_len += char_len;
 943            if c == '\n' {
 944                *self.output_position.row_mut() += 1;
 945                *self.output_position.column_mut() = 0;
 946            } else {
 947                *self.output_position.column_mut() += char_len as u32;
 948            }
 949
 950            if self.output_position >= transform_end {
 951                self.transforms.next();
 952                break;
 953            }
 954        }
 955
 956        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 957        self.input_chunk.text = suffix;
 958        Some(Chunk {
 959            text: prefix,
 960            ..self.input_chunk.clone()
 961        })
 962    }
 963}
 964
 965impl Iterator for WrapRows<'_> {
 966    type Item = RowInfo;
 967
 968    fn next(&mut self) -> Option<Self::Item> {
 969        if self.output_row > self.max_output_row {
 970            return None;
 971        }
 972
 973        let buffer_row = self.input_buffer_row;
 974        let soft_wrapped = self.soft_wrapped;
 975        let diff_status = self.input_buffer_row.diff_status;
 976
 977        self.output_row += 1;
 978        self.transforms
 979            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left);
 980        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 981            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 982            self.soft_wrapped = false;
 983        } else {
 984            self.soft_wrapped = true;
 985        }
 986
 987        Some(if soft_wrapped {
 988            RowInfo {
 989                buffer_id: None,
 990                buffer_row: None,
 991                multibuffer_row: None,
 992                diff_status,
 993                expand_info: None,
 994            }
 995        } else {
 996            buffer_row
 997        })
 998    }
 999}
1000
1001impl Transform {
1002    fn isomorphic(summary: TextSummary) -> Self {
1003        #[cfg(test)]
1004        assert!(!summary.lines.is_zero());
1005
1006        Self {
1007            summary: TransformSummary {
1008                input: summary.clone(),
1009                output: summary,
1010            },
1011            display_text: None,
1012        }
1013    }
1014
1015    fn wrap(indent: u32) -> Self {
1016        static WRAP_TEXT: LazyLock<String> = LazyLock::new(|| {
1017            let mut wrap_text = String::new();
1018            wrap_text.push('\n');
1019            wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
1020            wrap_text
1021        });
1022
1023        Self {
1024            summary: TransformSummary {
1025                input: TextSummary::default(),
1026                output: TextSummary {
1027                    lines: Point::new(1, indent),
1028                    first_line_chars: 0,
1029                    last_line_chars: indent,
1030                    longest_row: 1,
1031                    longest_row_chars: indent,
1032                },
1033            },
1034            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
1035        }
1036    }
1037
1038    fn is_isomorphic(&self) -> bool {
1039        self.display_text.is_none()
1040    }
1041}
1042
1043impl sum_tree::Item for Transform {
1044    type Summary = TransformSummary;
1045
1046    fn summary(&self, _cx: &()) -> Self::Summary {
1047        self.summary.clone()
1048    }
1049}
1050
1051fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
1052    if let Some(last_transform) = transforms.last_mut() {
1053        if last_transform.is_isomorphic() {
1054            last_transform.summary.input += &summary;
1055            last_transform.summary.output += &summary;
1056            return;
1057        }
1058    }
1059    transforms.push(Transform::isomorphic(summary));
1060}
1061
1062trait SumTreeExt {
1063    fn push_or_extend(&mut self, transform: Transform);
1064}
1065
1066impl SumTreeExt for SumTree<Transform> {
1067    fn push_or_extend(&mut self, transform: Transform) {
1068        let mut transform = Some(transform);
1069        self.update_last(
1070            |last_transform| {
1071                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
1072                    let transform = transform.take().unwrap();
1073                    last_transform.summary.input += &transform.summary.input;
1074                    last_transform.summary.output += &transform.summary.output;
1075                }
1076            },
1077            &(),
1078        );
1079
1080        if let Some(transform) = transform {
1081            self.push(transform, &());
1082        }
1083    }
1084}
1085
1086impl WrapPoint {
1087    pub fn new(row: u32, column: u32) -> Self {
1088        Self(Point::new(row, column))
1089    }
1090
1091    pub fn row(self) -> u32 {
1092        self.0.row
1093    }
1094
1095    pub fn row_mut(&mut self) -> &mut u32 {
1096        &mut self.0.row
1097    }
1098
1099    pub fn column(self) -> u32 {
1100        self.0.column
1101    }
1102
1103    pub fn column_mut(&mut self) -> &mut u32 {
1104        &mut self.0.column
1105    }
1106}
1107
1108impl sum_tree::Summary for TransformSummary {
1109    type Context = ();
1110
1111    fn zero(_cx: &()) -> Self {
1112        Default::default()
1113    }
1114
1115    fn add_summary(&mut self, other: &Self, _: &()) {
1116        self.input += &other.input;
1117        self.output += &other.output;
1118    }
1119}
1120
1121impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
1122    fn zero(_cx: &()) -> Self {
1123        Default::default()
1124    }
1125
1126    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1127        self.0 += summary.input.lines;
1128    }
1129}
1130
1131impl sum_tree::SeekTarget<'_, TransformSummary, TransformSummary> for TabPoint {
1132    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
1133        Ord::cmp(&self.0, &cursor_location.input.lines)
1134    }
1135}
1136
1137impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
1138    fn zero(_cx: &()) -> Self {
1139        Default::default()
1140    }
1141
1142    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1143        self.0 += summary.output.lines;
1144    }
1145}
1146
1147fn consolidate_wrap_edits(edits: Vec<WrapEdit>) -> Vec<WrapEdit> {
1148    let _old_alloc_ptr = edits.as_ptr();
1149    let mut wrap_edits = edits.into_iter();
1150
1151    if let Some(mut first_edit) = wrap_edits.next() {
1152        // This code relies on reusing allocations from the Vec<_> - at the time of writing .flatten() prevents them.
1153        #[allow(clippy::filter_map_identity)]
1154        let mut v: Vec<_> = wrap_edits
1155            .scan(&mut first_edit, |prev_edit, edit| {
1156                if prev_edit.old.end >= edit.old.start {
1157                    prev_edit.old.end = edit.old.end;
1158                    prev_edit.new.end = edit.new.end;
1159                    Some(None) // Skip this edit, it's merged
1160                } else {
1161                    let prev = std::mem::replace(*prev_edit, edit);
1162                    Some(Some(prev)) // Yield the previous edit
1163                }
1164            })
1165            .filter_map(|x| x)
1166            .collect();
1167        v.push(first_edit.clone());
1168        debug_assert_eq!(v.as_ptr(), _old_alloc_ptr, "Wrap edits were reallocated");
1169        v
1170    } else {
1171        vec![]
1172    }
1173}
1174
1175#[cfg(test)]
1176mod tests {
1177    use super::*;
1178    use crate::{
1179        MultiBuffer,
1180        display_map::{fold_map::FoldMap, inlay_map::InlayMap, tab_map::TabMap},
1181        test::test_font,
1182    };
1183    use gpui::{LineFragment, px, test::observe};
1184    use rand::prelude::*;
1185    use settings::SettingsStore;
1186    use smol::stream::StreamExt;
1187    use std::{cmp, env, num::NonZeroU32};
1188    use text::Rope;
1189    use theme::LoadThemes;
1190
1191    #[gpui::test(iterations = 100)]
1192    async fn test_random_wraps(cx: &mut gpui::TestAppContext, mut rng: StdRng) {
1193        // todo this test is flaky
1194        init_test(cx);
1195
1196        cx.background_executor.set_block_on_ticks(0..=50);
1197        let operations = env::var("OPERATIONS")
1198            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1199            .unwrap_or(10);
1200
1201        let text_system = cx.read(|cx| cx.text_system().clone());
1202        let mut wrap_width = if rng.gen_bool(0.1) {
1203            None
1204        } else {
1205            Some(px(rng.gen_range(0.0..=1000.0)))
1206        };
1207        let tab_size = NonZeroU32::new(rng.gen_range(1..=4)).unwrap();
1208
1209        let font = test_font();
1210        let _font_id = text_system.font_id(&font);
1211        let font_size = px(14.0);
1212
1213        log::info!("Tab size: {}", tab_size);
1214        log::info!("Wrap width: {:?}", wrap_width);
1215
1216        let buffer = cx.update(|cx| {
1217            if rng.r#gen() {
1218                MultiBuffer::build_random(&mut rng, cx)
1219            } else {
1220                let len = rng.gen_range(0..10);
1221                let text = util::RandomCharIter::new(&mut rng)
1222                    .take(len)
1223                    .collect::<String>();
1224                MultiBuffer::build_simple(&text, cx)
1225            }
1226        });
1227        let mut buffer_snapshot = buffer.read_with(cx, |buffer, cx| buffer.snapshot(cx));
1228        log::info!("Buffer text: {:?}", buffer_snapshot.text());
1229        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1230        log::info!("InlayMap text: {:?}", inlay_snapshot.text());
1231        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot.clone());
1232        log::info!("FoldMap text: {:?}", fold_snapshot.text());
1233        let (mut tab_map, _) = TabMap::new(fold_snapshot.clone(), tab_size);
1234        let tabs_snapshot = tab_map.set_max_expansion_column(32);
1235        log::info!("TabMap text: {:?}", tabs_snapshot.text());
1236
1237        let mut line_wrapper = text_system.line_wrapper(font.clone(), font_size);
1238        let expected_text = wrap_text(&tabs_snapshot, wrap_width, &mut line_wrapper);
1239
1240        let (wrap_map, _) =
1241            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font, font_size, wrap_width, cx));
1242        let mut notifications = observe(&wrap_map, cx);
1243
1244        if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1245            notifications.next().await.unwrap();
1246        }
1247
1248        let (initial_snapshot, _) = wrap_map.update(cx, |map, cx| {
1249            assert!(!map.is_rewrapping());
1250            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1251        });
1252
1253        let actual_text = initial_snapshot.text();
1254        assert_eq!(
1255            actual_text,
1256            expected_text,
1257            "unwrapped text is: {:?}",
1258            tabs_snapshot.text()
1259        );
1260        log::info!("Wrapped text: {:?}", actual_text);
1261
1262        let mut next_inlay_id = 0;
1263        let mut edits = Vec::new();
1264        for _i in 0..operations {
1265            log::info!("{} ==============================================", _i);
1266
1267            let mut buffer_edits = Vec::new();
1268            match rng.gen_range(0..=100) {
1269                0..=19 => {
1270                    wrap_width = if rng.gen_bool(0.2) {
1271                        None
1272                    } else {
1273                        Some(px(rng.gen_range(0.0..=1000.0)))
1274                    };
1275                    log::info!("Setting wrap width to {:?}", wrap_width);
1276                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1277                }
1278                20..=39 => {
1279                    for (fold_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1280                        let (tabs_snapshot, tab_edits) =
1281                            tab_map.sync(fold_snapshot, fold_edits, tab_size);
1282                        let (mut snapshot, wrap_edits) =
1283                            wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1284                        snapshot.check_invariants();
1285                        snapshot.verify_chunks(&mut rng);
1286                        edits.push((snapshot, wrap_edits));
1287                    }
1288                }
1289                40..=59 => {
1290                    let (inlay_snapshot, inlay_edits) =
1291                        inlay_map.randomly_mutate(&mut next_inlay_id, &mut rng);
1292                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1293                    let (tabs_snapshot, tab_edits) =
1294                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1295                    let (mut snapshot, wrap_edits) =
1296                        wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1297                    snapshot.check_invariants();
1298                    snapshot.verify_chunks(&mut rng);
1299                    edits.push((snapshot, wrap_edits));
1300                }
1301                _ => {
1302                    buffer.update(cx, |buffer, cx| {
1303                        let subscription = buffer.subscribe();
1304                        let edit_count = rng.gen_range(1..=5);
1305                        buffer.randomly_mutate(&mut rng, edit_count, cx);
1306                        buffer_snapshot = buffer.snapshot(cx);
1307                        buffer_edits.extend(subscription.consume());
1308                    });
1309                }
1310            }
1311
1312            log::info!("Buffer text: {:?}", buffer_snapshot.text());
1313            let (inlay_snapshot, inlay_edits) =
1314                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1315            log::info!("InlayMap text: {:?}", inlay_snapshot.text());
1316            let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1317            log::info!("FoldMap text: {:?}", fold_snapshot.text());
1318            let (tabs_snapshot, tab_edits) = tab_map.sync(fold_snapshot, fold_edits, tab_size);
1319            log::info!("TabMap text: {:?}", tabs_snapshot.text());
1320
1321            let expected_text = wrap_text(&tabs_snapshot, wrap_width, &mut line_wrapper);
1322            let (mut snapshot, wrap_edits) =
1323                wrap_map.update(cx, |map, cx| map.sync(tabs_snapshot.clone(), tab_edits, cx));
1324            snapshot.check_invariants();
1325            snapshot.verify_chunks(&mut rng);
1326            edits.push((snapshot, wrap_edits));
1327
1328            if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1329                log::info!("Waiting for wrapping to finish");
1330                while wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1331                    notifications.next().await.unwrap();
1332                }
1333                wrap_map.read_with(cx, |map, _| assert!(map.pending_edits.is_empty()));
1334            }
1335
1336            if !wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1337                let (mut wrapped_snapshot, wrap_edits) = wrap_map.update(cx, |map, cx| {
1338                    map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1339                });
1340                let actual_text = wrapped_snapshot.text();
1341                let actual_longest_row = wrapped_snapshot.longest_row();
1342                log::info!("Wrapping finished: {:?}", actual_text);
1343                wrapped_snapshot.check_invariants();
1344                wrapped_snapshot.verify_chunks(&mut rng);
1345                edits.push((wrapped_snapshot.clone(), wrap_edits));
1346                assert_eq!(
1347                    actual_text,
1348                    expected_text,
1349                    "unwrapped text is: {:?}",
1350                    tabs_snapshot.text()
1351                );
1352
1353                let mut summary = TextSummary::default();
1354                for (ix, item) in wrapped_snapshot
1355                    .transforms
1356                    .items(&())
1357                    .into_iter()
1358                    .enumerate()
1359                {
1360                    summary += &item.summary.output;
1361                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1362                }
1363
1364                if tab_size.get() == 1
1365                    || !wrapped_snapshot
1366                        .tab_snapshot
1367                        .fold_snapshot
1368                        .text()
1369                        .contains('\t')
1370                {
1371                    let mut expected_longest_rows = Vec::new();
1372                    let mut longest_line_len = -1;
1373                    for (row, line) in expected_text.split('\n').enumerate() {
1374                        let line_char_count = line.chars().count() as isize;
1375                        if line_char_count > longest_line_len {
1376                            expected_longest_rows.clear();
1377                            longest_line_len = line_char_count;
1378                        }
1379                        if line_char_count >= longest_line_len {
1380                            expected_longest_rows.push(row as u32);
1381                        }
1382                    }
1383
1384                    assert!(
1385                        expected_longest_rows.contains(&actual_longest_row),
1386                        "incorrect longest row {}. expected {:?} with length {}",
1387                        actual_longest_row,
1388                        expected_longest_rows,
1389                        longest_line_len,
1390                    )
1391                }
1392            }
1393        }
1394
1395        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1396        for (snapshot, patch) in edits {
1397            let snapshot_text = Rope::from(snapshot.text().as_str());
1398            for edit in &patch {
1399                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1400                let old_end = initial_text.point_to_offset(cmp::min(
1401                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1402                    initial_text.max_point(),
1403                ));
1404                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1405                let new_end = snapshot_text.point_to_offset(cmp::min(
1406                    Point::new(edit.new.end, 0),
1407                    snapshot_text.max_point(),
1408                ));
1409                let new_text = snapshot_text
1410                    .chunks_in_range(new_start..new_end)
1411                    .collect::<String>();
1412
1413                initial_text.replace(old_start..old_end, &new_text);
1414            }
1415            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1416        }
1417
1418        if wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1419            log::info!("Waiting for wrapping to finish");
1420            while wrap_map.read_with(cx, |map, _| map.is_rewrapping()) {
1421                notifications.next().await.unwrap();
1422            }
1423        }
1424        wrap_map.read_with(cx, |map, _| assert!(map.pending_edits.is_empty()));
1425    }
1426
1427    fn init_test(cx: &mut gpui::TestAppContext) {
1428        cx.update(|cx| {
1429            let settings = SettingsStore::test(cx);
1430            cx.set_global(settings);
1431            theme::init(LoadThemes::JustBase, cx);
1432        });
1433    }
1434
1435    fn wrap_text(
1436        tab_snapshot: &TabSnapshot,
1437        wrap_width: Option<Pixels>,
1438        line_wrapper: &mut LineWrapper,
1439    ) -> String {
1440        if let Some(wrap_width) = wrap_width {
1441            let mut wrapped_text = String::new();
1442            for (row, line) in tab_snapshot.text().split('\n').enumerate() {
1443                if row > 0 {
1444                    wrapped_text.push('\n');
1445                }
1446
1447                let mut prev_ix = 0;
1448                for boundary in line_wrapper.wrap_line(&[LineFragment::text(&line)], wrap_width) {
1449                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1450                    wrapped_text.push('\n');
1451                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1452                    prev_ix = boundary.ix;
1453                }
1454                wrapped_text.push_str(&line[prev_ix..]);
1455            }
1456
1457            wrapped_text
1458        } else {
1459            tab_snapshot.text()
1460        }
1461    }
1462
1463    impl WrapSnapshot {
1464        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1465            for _ in 0..5 {
1466                let mut end_row = rng.gen_range(0..=self.max_point().row());
1467                let start_row = rng.gen_range(0..=end_row);
1468                end_row += 1;
1469
1470                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1471                if expected_text.ends_with('\n') {
1472                    expected_text.push('\n');
1473                }
1474                let mut expected_text = expected_text
1475                    .lines()
1476                    .take((end_row - start_row) as usize)
1477                    .collect::<Vec<_>>()
1478                    .join("\n");
1479                if end_row <= self.max_point().row() {
1480                    expected_text.push('\n');
1481                }
1482
1483                let actual_text = self
1484                    .chunks(start_row..end_row, true, Highlights::default())
1485                    .map(|c| c.text)
1486                    .collect::<String>();
1487                assert_eq!(
1488                    expected_text,
1489                    actual_text,
1490                    "chunks != highlighted_chunks for rows {:?}",
1491                    start_row..end_row
1492                );
1493            }
1494        }
1495    }
1496}