1use super::{
   2    fold_map,
   3    tab_map::{self, TabEdit, TabPoint, TabSnapshot},
   4};
   5use crate::{MultiBufferSnapshot, Point};
   6use gpui::{
   7    fonts::FontId, text_layout::LineWrapper, Entity, ModelContext, ModelHandle, MutableAppContext,
   8    Task,
   9};
  10use language::Chunk;
  11use lazy_static::lazy_static;
  12use smol::future::yield_now;
  13use std::{collections::VecDeque, mem, ops::Range, time::Duration};
  14use sum_tree::{Bias, Cursor, SumTree};
  15use text::Patch;
  16use theme::SyntaxTheme;
  17
  18pub use super::tab_map::TextSummary;
  19pub type WrapEdit = text::Edit<u32>;
  20
  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<f32>,
  27    background_task: Option<Task<()>>,
  28    font: (FontId, f32),
  29}
  30
  31impl Entity for WrapMap {
  32    type Event = ();
  33}
  34
  35#[derive(Clone)]
  36pub struct WrapSnapshot {
  37    tab_snapshot: TabSnapshot,
  38    transforms: SumTree<Transform>,
  39    interpolated: bool,
  40}
  41
  42#[derive(Clone, Debug, Default, Eq, PartialEq)]
  43struct Transform {
  44    summary: TransformSummary,
  45    display_text: Option<&'static str>,
  46}
  47
  48#[derive(Clone, Debug, Default, Eq, PartialEq)]
  49struct TransformSummary {
  50    input: TextSummary,
  51    output: TextSummary,
  52}
  53
  54#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  55pub struct WrapPoint(pub super::Point);
  56
  57pub struct WrapChunks<'a> {
  58    input_chunks: tab_map::TabChunks<'a>,
  59    input_chunk: Chunk<'a>,
  60    output_position: WrapPoint,
  61    max_output_row: u32,
  62    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  63}
  64
  65pub struct WrapBufferRows<'a> {
  66    input_buffer_rows: fold_map::FoldBufferRows<'a>,
  67    input_buffer_row: u32,
  68    output_row: u32,
  69    soft_wrapped: bool,
  70    max_output_row: u32,
  71    transforms: Cursor<'a, Transform, (WrapPoint, TabPoint)>,
  72}
  73
  74impl WrapMap {
  75    pub fn new(
  76        tab_snapshot: TabSnapshot,
  77        font_id: FontId,
  78        font_size: f32,
  79        wrap_width: Option<f32>,
  80        cx: &mut MutableAppContext,
  81    ) -> (ModelHandle<Self>, WrapSnapshot) {
  82        let handle = cx.add_model(|cx| {
  83            let mut this = Self {
  84                font: (font_id, font_size),
  85                wrap_width: None,
  86                pending_edits: Default::default(),
  87                interpolated_edits: Default::default(),
  88                edits_since_sync: Default::default(),
  89                snapshot: WrapSnapshot::new(tab_snapshot),
  90                background_task: None,
  91            };
  92            this.set_wrap_width(wrap_width, cx);
  93            mem::take(&mut this.edits_since_sync);
  94            this
  95        });
  96        let snapshot = handle.read(cx).snapshot.clone();
  97        (handle, snapshot)
  98    }
  99
 100    #[cfg(test)]
 101    pub fn is_rewrapping(&self) -> bool {
 102        self.background_task.is_some()
 103    }
 104
 105    pub fn sync(
 106        &mut self,
 107        tab_snapshot: TabSnapshot,
 108        edits: Vec<TabEdit>,
 109        cx: &mut ModelContext<Self>,
 110    ) -> (WrapSnapshot, Vec<WrapEdit>) {
 111        if self.wrap_width.is_some() {
 112            self.pending_edits.push_back((tab_snapshot, edits));
 113            self.flush_edits(cx);
 114        } else {
 115            self.edits_since_sync = self
 116                .edits_since_sync
 117                .compose(&self.snapshot.interpolate(tab_snapshot, &edits));
 118            self.snapshot.interpolated = false;
 119        }
 120
 121        (
 122            self.snapshot.clone(),
 123            mem::take(&mut self.edits_since_sync).into_inner(),
 124        )
 125    }
 126
 127    pub fn set_font(&mut self, font_id: FontId, font_size: f32, cx: &mut ModelContext<Self>) {
 128        if (font_id, font_size) != self.font {
 129            self.font = (font_id, font_size);
 130            self.rewrap(cx)
 131        }
 132    }
 133
 134    pub fn set_wrap_width(&mut self, wrap_width: Option<f32>, cx: &mut ModelContext<Self>) -> bool {
 135        if wrap_width == self.wrap_width {
 136            return false;
 137        }
 138
 139        self.wrap_width = wrap_width;
 140        self.rewrap(cx);
 141        true
 142    }
 143
 144    fn rewrap(&mut self, cx: &mut ModelContext<Self>) {
 145        self.background_task.take();
 146        self.interpolated_edits.clear();
 147        self.pending_edits.clear();
 148
 149        if let Some(wrap_width) = self.wrap_width {
 150            let mut new_snapshot = self.snapshot.clone();
 151            let font_cache = cx.font_cache().clone();
 152            let (font_id, font_size) = self.font;
 153            let task = cx.background().spawn(async move {
 154                let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 155                let tab_snapshot = new_snapshot.tab_snapshot.clone();
 156                let range = TabPoint::zero()..tab_snapshot.max_point();
 157                let edits = new_snapshot
 158                    .update(
 159                        tab_snapshot,
 160                        &[TabEdit {
 161                            old: range.clone(),
 162                            new: range.clone(),
 163                        }],
 164                        wrap_width,
 165                        &mut line_wrapper,
 166                    )
 167                    .await;
 168                (new_snapshot, edits)
 169            });
 170
 171            match cx
 172                .background()
 173                .block_with_timeout(Duration::from_millis(5), task)
 174            {
 175                Ok((snapshot, edits)) => {
 176                    self.snapshot = snapshot;
 177                    self.edits_since_sync = self.edits_since_sync.compose(&edits);
 178                    cx.notify();
 179                }
 180                Err(wrap_task) => {
 181                    self.background_task = Some(cx.spawn(|this, mut cx| async move {
 182                        let (snapshot, edits) = wrap_task.await;
 183                        this.update(&mut cx, |this, cx| {
 184                            this.snapshot = snapshot;
 185                            this.edits_since_sync = this
 186                                .edits_since_sync
 187                                .compose(mem::take(&mut this.interpolated_edits).invert())
 188                                .compose(&edits);
 189                            this.background_task = None;
 190                            this.flush_edits(cx);
 191                            cx.notify();
 192                        });
 193                    }));
 194                }
 195            }
 196        } else {
 197            let old_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 198            self.snapshot.transforms = SumTree::new();
 199            let summary = self.snapshot.tab_snapshot.text_summary();
 200            if !summary.lines.is_zero() {
 201                self.snapshot
 202                    .transforms
 203                    .push(Transform::isomorphic(summary), &());
 204            }
 205            let new_rows = self.snapshot.transforms.summary().output.lines.row + 1;
 206            self.snapshot.interpolated = false;
 207            self.edits_since_sync = self.edits_since_sync.compose(&Patch::new(vec![WrapEdit {
 208                old: 0..old_rows,
 209                new: 0..new_rows,
 210            }]));
 211        }
 212    }
 213
 214    fn flush_edits(&mut self, cx: &mut ModelContext<Self>) {
 215        if !self.snapshot.interpolated {
 216            let mut to_remove_len = 0;
 217            for (tab_snapshot, _) in &self.pending_edits {
 218                if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 219                    to_remove_len += 1;
 220                } else {
 221                    break;
 222                }
 223            }
 224            self.pending_edits.drain(..to_remove_len);
 225        }
 226
 227        if self.pending_edits.is_empty() {
 228            return;
 229        }
 230
 231        if let Some(wrap_width) = self.wrap_width {
 232            if self.background_task.is_none() {
 233                let pending_edits = self.pending_edits.clone();
 234                let mut snapshot = self.snapshot.clone();
 235                let font_cache = cx.font_cache().clone();
 236                let (font_id, font_size) = self.font;
 237                let update_task = cx.background().spawn(async move {
 238                    let mut line_wrapper = font_cache.line_wrapper(font_id, font_size);
 239
 240                    let mut edits = Patch::default();
 241                    for (tab_snapshot, tab_edits) in pending_edits {
 242                        let wrap_edits = snapshot
 243                            .update(tab_snapshot, &tab_edits, wrap_width, &mut line_wrapper)
 244                            .await;
 245                        edits = edits.compose(&wrap_edits);
 246                    }
 247                    (snapshot, edits)
 248                });
 249
 250                match cx
 251                    .background()
 252                    .block_with_timeout(Duration::from_millis(1), update_task)
 253                {
 254                    Ok((snapshot, output_edits)) => {
 255                        self.snapshot = snapshot;
 256                        self.edits_since_sync = self.edits_since_sync.compose(&output_edits);
 257                    }
 258                    Err(update_task) => {
 259                        self.background_task = Some(cx.spawn(|this, mut cx| async move {
 260                            let (snapshot, edits) = update_task.await;
 261                            this.update(&mut cx, |this, cx| {
 262                                this.snapshot = snapshot;
 263                                this.edits_since_sync = this
 264                                    .edits_since_sync
 265                                    .compose(mem::take(&mut this.interpolated_edits).invert())
 266                                    .compose(&edits);
 267                                this.background_task = None;
 268                                this.flush_edits(cx);
 269                                cx.notify();
 270                            });
 271                        }));
 272                    }
 273                }
 274            }
 275        }
 276
 277        let was_interpolated = self.snapshot.interpolated;
 278        let mut to_remove_len = 0;
 279        for (tab_snapshot, edits) in &self.pending_edits {
 280            if tab_snapshot.version() <= self.snapshot.tab_snapshot.version() {
 281                to_remove_len += 1;
 282            } else {
 283                let interpolated_edits = self.snapshot.interpolate(tab_snapshot.clone(), &edits);
 284                self.edits_since_sync = self.edits_since_sync.compose(&interpolated_edits);
 285                self.interpolated_edits = self.interpolated_edits.compose(&interpolated_edits);
 286            }
 287        }
 288
 289        if !was_interpolated {
 290            self.pending_edits.drain(..to_remove_len);
 291        }
 292    }
 293}
 294
 295impl WrapSnapshot {
 296    fn new(tab_snapshot: TabSnapshot) -> Self {
 297        let mut transforms = SumTree::new();
 298        let extent = tab_snapshot.text_summary();
 299        if !extent.lines.is_zero() {
 300            transforms.push(Transform::isomorphic(extent), &());
 301        }
 302        Self {
 303            transforms,
 304            tab_snapshot,
 305            interpolated: true,
 306        }
 307    }
 308
 309    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 310        self.tab_snapshot.buffer_snapshot()
 311    }
 312
 313    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 314        let mut new_transforms;
 315        if tab_edits.is_empty() {
 316            new_transforms = self.transforms.clone();
 317        } else {
 318            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 319
 320            let mut tab_edits_iter = tab_edits.iter().peekable();
 321            new_transforms =
 322                old_cursor.slice(&tab_edits_iter.peek().unwrap().old.start, Bias::Right, &());
 323
 324            while let Some(edit) = tab_edits_iter.next() {
 325                if edit.new.start > TabPoint::from(new_transforms.summary().input.lines) {
 326                    let summary = new_tab_snapshot.text_summary_for_range(
 327                        TabPoint::from(new_transforms.summary().input.lines)..edit.new.start,
 328                    );
 329                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 330                }
 331
 332                if !edit.new.is_empty() {
 333                    new_transforms.push_or_extend(Transform::isomorphic(
 334                        new_tab_snapshot.text_summary_for_range(edit.new.clone()),
 335                    ));
 336                }
 337
 338                old_cursor.seek_forward(&edit.old.end, Bias::Right, &());
 339                if let Some(next_edit) = tab_edits_iter.peek() {
 340                    if next_edit.old.start > old_cursor.end(&()) {
 341                        if old_cursor.end(&()) > edit.old.end {
 342                            let summary = self
 343                                .tab_snapshot
 344                                .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 345                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 346                        }
 347
 348                        old_cursor.next(&());
 349                        new_transforms.push_tree(
 350                            old_cursor.slice(&next_edit.old.start, Bias::Right, &()),
 351                            &(),
 352                        );
 353                    }
 354                } else {
 355                    if old_cursor.end(&()) > edit.old.end {
 356                        let summary = self
 357                            .tab_snapshot
 358                            .text_summary_for_range(edit.old.end..old_cursor.end(&()));
 359                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 360                    }
 361                    old_cursor.next(&());
 362                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 363                }
 364            }
 365        }
 366
 367        let old_snapshot = mem::replace(
 368            self,
 369            WrapSnapshot {
 370                tab_snapshot: new_tab_snapshot,
 371                transforms: new_transforms,
 372                interpolated: true,
 373            },
 374        );
 375        self.check_invariants();
 376        old_snapshot.compute_edits(tab_edits, self)
 377    }
 378
 379    async fn update(
 380        &mut self,
 381        new_tab_snapshot: TabSnapshot,
 382        tab_edits: &[TabEdit],
 383        wrap_width: f32,
 384        line_wrapper: &mut LineWrapper,
 385    ) -> Patch<u32> {
 386        #[derive(Debug)]
 387        struct RowEdit {
 388            old_rows: Range<u32>,
 389            new_rows: Range<u32>,
 390        }
 391
 392        let mut tab_edits_iter = tab_edits.into_iter().peekable();
 393        let mut row_edits = Vec::new();
 394        while let Some(edit) = tab_edits_iter.next() {
 395            let mut row_edit = RowEdit {
 396                old_rows: edit.old.start.row()..edit.old.end.row() + 1,
 397                new_rows: edit.new.start.row()..edit.new.end.row() + 1,
 398            };
 399
 400            while let Some(next_edit) = tab_edits_iter.peek() {
 401                if next_edit.old.start.row() <= row_edit.old_rows.end {
 402                    row_edit.old_rows.end = next_edit.old.end.row() + 1;
 403                    row_edit.new_rows.end = next_edit.new.end.row() + 1;
 404                    tab_edits_iter.next();
 405                } else {
 406                    break;
 407                }
 408            }
 409
 410            row_edits.push(row_edit);
 411        }
 412
 413        let mut new_transforms;
 414        if row_edits.is_empty() {
 415            new_transforms = self.transforms.clone();
 416        } else {
 417            let mut row_edits = row_edits.into_iter().peekable();
 418            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 419
 420            new_transforms = old_cursor.slice(
 421                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 422                Bias::Right,
 423                &(),
 424            );
 425
 426            while let Some(edit) = row_edits.next() {
 427                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 428                    let summary = new_tab_snapshot.text_summary_for_range(
 429                        TabPoint(new_transforms.summary().input.lines)
 430                            ..TabPoint::new(edit.new_rows.start, 0),
 431                    );
 432                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 433                }
 434
 435                let mut line = String::new();
 436                let mut remaining = None;
 437                let mut chunks = new_tab_snapshot.chunks(
 438                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 439                    None,
 440                );
 441                let mut edit_transforms = Vec::<Transform>::new();
 442                for _ in edit.new_rows.start..edit.new_rows.end {
 443                    while let Some(chunk) =
 444                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 445                    {
 446                        if let Some(ix) = chunk.find('\n') {
 447                            line.push_str(&chunk[..ix + 1]);
 448                            remaining = Some(&chunk[ix + 1..]);
 449                            break;
 450                        } else {
 451                            line.push_str(chunk)
 452                        }
 453                    }
 454
 455                    if line.is_empty() {
 456                        break;
 457                    }
 458
 459                    let mut prev_boundary_ix = 0;
 460                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 461                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 462                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 463                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 464                        prev_boundary_ix = boundary.ix;
 465                    }
 466
 467                    if prev_boundary_ix < line.len() {
 468                        push_isomorphic(
 469                            &mut edit_transforms,
 470                            TextSummary::from(&line[prev_boundary_ix..]),
 471                        );
 472                    }
 473
 474                    line.clear();
 475                    yield_now().await;
 476                }
 477
 478                let mut edit_transforms = edit_transforms.into_iter();
 479                if let Some(transform) = edit_transforms.next() {
 480                    new_transforms.push_or_extend(transform);
 481                }
 482                new_transforms.extend(edit_transforms, &());
 483
 484                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 485                if let Some(next_edit) = row_edits.peek() {
 486                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 487                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 488                            let summary = self.tab_snapshot.text_summary_for_range(
 489                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 490                            );
 491                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 492                        }
 493                        old_cursor.next(&());
 494                        new_transforms.push_tree(
 495                            old_cursor.slice(
 496                                &TabPoint::new(next_edit.old_rows.start, 0),
 497                                Bias::Right,
 498                                &(),
 499                            ),
 500                            &(),
 501                        );
 502                    }
 503                } else {
 504                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 505                        let summary = self.tab_snapshot.text_summary_for_range(
 506                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 507                        );
 508                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 509                    }
 510                    old_cursor.next(&());
 511                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 512                }
 513            }
 514        }
 515
 516        let old_snapshot = mem::replace(
 517            self,
 518            WrapSnapshot {
 519                tab_snapshot: new_tab_snapshot,
 520                transforms: new_transforms,
 521                interpolated: false,
 522            },
 523        );
 524        self.check_invariants();
 525        old_snapshot.compute_edits(tab_edits, self)
 526    }
 527
 528    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &WrapSnapshot) -> Patch<u32> {
 529        let mut wrap_edits = Vec::new();
 530        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 531        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 532        for mut tab_edit in tab_edits.iter().cloned() {
 533            tab_edit.old.start.0.column = 0;
 534            tab_edit.old.end.0 += Point::new(1, 0);
 535            tab_edit.new.start.0.column = 0;
 536            tab_edit.new.end.0 += Point::new(1, 0);
 537
 538            old_cursor.seek(&tab_edit.old.start, Bias::Right, &());
 539            let mut old_start = old_cursor.start().output.lines;
 540            old_start += tab_edit.old.start.0 - old_cursor.start().input.lines;
 541
 542            old_cursor.seek(&tab_edit.old.end, Bias::Right, &());
 543            let mut old_end = old_cursor.start().output.lines;
 544            old_end += tab_edit.old.end.0 - old_cursor.start().input.lines;
 545
 546            new_cursor.seek(&tab_edit.new.start, Bias::Right, &());
 547            let mut new_start = new_cursor.start().output.lines;
 548            new_start += tab_edit.new.start.0 - new_cursor.start().input.lines;
 549
 550            new_cursor.seek(&tab_edit.new.end, Bias::Right, &());
 551            let mut new_end = new_cursor.start().output.lines;
 552            new_end += tab_edit.new.end.0 - new_cursor.start().input.lines;
 553
 554            wrap_edits.push(WrapEdit {
 555                old: old_start.row..old_end.row,
 556                new: new_start.row..new_end.row,
 557            });
 558        }
 559
 560        consolidate_wrap_edits(&mut wrap_edits);
 561        Patch::new(wrap_edits)
 562    }
 563
 564    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 565        self.chunks(wrap_row..self.max_point().row() + 1, None)
 566            .map(|h| h.text)
 567    }
 568
 569    pub fn chunks<'a>(
 570        &'a self,
 571        rows: Range<u32>,
 572        theme: Option<&'a SyntaxTheme>,
 573    ) -> WrapChunks<'a> {
 574        let output_start = WrapPoint::new(rows.start, 0);
 575        let output_end = WrapPoint::new(rows.end, 0);
 576        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 577        transforms.seek(&output_start, Bias::Right, &());
 578        let mut input_start = TabPoint(transforms.start().1 .0);
 579        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 580            input_start.0 += output_start.0 - transforms.start().0 .0;
 581        }
 582        let input_end = self
 583            .to_tab_point(output_end)
 584            .min(self.tab_snapshot.max_point());
 585        WrapChunks {
 586            input_chunks: self.tab_snapshot.chunks(input_start..input_end, theme),
 587            input_chunk: Default::default(),
 588            output_position: output_start,
 589            max_output_row: rows.end,
 590            transforms,
 591        }
 592    }
 593
 594    pub fn text_summary(&self) -> TextSummary {
 595        self.transforms.summary().output
 596    }
 597
 598    pub fn max_point(&self) -> WrapPoint {
 599        WrapPoint(self.transforms.summary().output.lines)
 600    }
 601
 602    pub fn line_len(&self, row: u32) -> u32 {
 603        let mut len = 0;
 604        for chunk in self.text_chunks(row) {
 605            if let Some(newline_ix) = chunk.find('\n') {
 606                len += newline_ix;
 607                break;
 608            } else {
 609                len += chunk.len();
 610            }
 611        }
 612        len as u32
 613    }
 614
 615    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 616        let mut cursor = self.transforms.cursor::<WrapPoint>();
 617        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 618        cursor.item().and_then(|transform| {
 619            if transform.is_isomorphic() {
 620                None
 621            } else {
 622                Some(transform.summary.output.lines.column)
 623            }
 624        })
 625    }
 626
 627    pub fn longest_row(&self) -> u32 {
 628        self.transforms.summary().output.longest_row
 629    }
 630
 631    pub fn buffer_rows(&self, start_row: u32) -> WrapBufferRows {
 632        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 633        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 634        let mut input_row = transforms.start().1.row();
 635        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 636            input_row += start_row - transforms.start().0.row();
 637        }
 638        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 639        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 640        let input_buffer_row = input_buffer_rows.next().unwrap();
 641        WrapBufferRows {
 642            transforms,
 643            input_buffer_row,
 644            input_buffer_rows,
 645            output_row: start_row,
 646            soft_wrapped,
 647            max_output_row: self.max_point().row(),
 648        }
 649    }
 650
 651    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 652        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 653        cursor.seek(&point, Bias::Right, &());
 654        let mut tab_point = cursor.start().1 .0;
 655        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 656            tab_point += point.0 - cursor.start().0 .0;
 657        }
 658        TabPoint(tab_point)
 659    }
 660
 661    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 662        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 663    }
 664
 665    pub fn from_point(&self, point: Point, bias: Bias) -> WrapPoint {
 666        self.from_tab_point(self.tab_snapshot.from_point(point, bias))
 667    }
 668
 669    pub fn from_tab_point(&self, point: TabPoint) -> WrapPoint {
 670        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 671        cursor.seek(&point, Bias::Right, &());
 672        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 673    }
 674
 675    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 676        if bias == Bias::Left {
 677            let mut cursor = self.transforms.cursor::<WrapPoint>();
 678            cursor.seek(&point, Bias::Right, &());
 679            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 680                point = *cursor.start();
 681                *point.column_mut() -= 1;
 682            }
 683        }
 684
 685        self.from_tab_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 686    }
 687
 688    fn check_invariants(&self) {
 689        #[cfg(test)]
 690        {
 691            assert_eq!(
 692                TabPoint::from(self.transforms.summary().input.lines),
 693                self.tab_snapshot.max_point()
 694            );
 695
 696            {
 697                let mut transforms = self.transforms.cursor::<()>().peekable();
 698                while let Some(transform) = transforms.next() {
 699                    if let Some(next_transform) = transforms.peek() {
 700                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 701                    }
 702                }
 703            }
 704
 705            let mut expected_buffer_rows = Vec::new();
 706            let mut buffer_row = 0;
 707            let mut prev_tab_row = 0;
 708            for display_row in 0..=self.max_point().row() {
 709                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 710                let soft_wrapped;
 711                if tab_point.row() == prev_tab_row {
 712                    soft_wrapped = display_row != 0;
 713                } else {
 714                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 715                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 716                    buffer_row = buffer_point.row;
 717                    prev_tab_row = tab_point.row();
 718                    soft_wrapped = false;
 719                }
 720                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
 721            }
 722
 723            for start_display_row in 0..expected_buffer_rows.len() {
 724                assert_eq!(
 725                    self.buffer_rows(start_display_row as u32)
 726                        .collect::<Vec<_>>(),
 727                    &expected_buffer_rows[start_display_row..],
 728                    "invalid buffer_rows({}..)",
 729                    start_display_row
 730                );
 731            }
 732        }
 733    }
 734}
 735
 736impl<'a> Iterator for WrapChunks<'a> {
 737    type Item = Chunk<'a>;
 738
 739    fn next(&mut self) -> Option<Self::Item> {
 740        if self.output_position.row() >= self.max_output_row {
 741            return None;
 742        }
 743
 744        let transform = self.transforms.item()?;
 745        if let Some(display_text) = transform.display_text {
 746            let mut start_ix = 0;
 747            let mut end_ix = display_text.len();
 748            let mut summary = transform.summary.output.lines;
 749
 750            if self.output_position > self.transforms.start().0 {
 751                // Exclude newline starting prior to the desired row.
 752                start_ix = 1;
 753                summary.row = 0;
 754            } else if self.output_position.row() + 1 >= self.max_output_row {
 755                // Exclude soft indentation ending after the desired row.
 756                end_ix = 1;
 757                summary.column = 0;
 758            }
 759
 760            self.output_position.0 += summary;
 761            self.transforms.next(&());
 762            return Some(Chunk {
 763                text: &display_text[start_ix..end_ix],
 764                ..self.input_chunk
 765            });
 766        }
 767
 768        if self.input_chunk.text.is_empty() {
 769            self.input_chunk = self.input_chunks.next().unwrap();
 770        }
 771
 772        let mut input_len = 0;
 773        let transform_end = self.transforms.end(&()).0;
 774        for c in self.input_chunk.text.chars() {
 775            let char_len = c.len_utf8();
 776            input_len += char_len;
 777            if c == '\n' {
 778                *self.output_position.row_mut() += 1;
 779                *self.output_position.column_mut() = 0;
 780            } else {
 781                *self.output_position.column_mut() += char_len as u32;
 782            }
 783
 784            if self.output_position >= transform_end {
 785                self.transforms.next(&());
 786                break;
 787            }
 788        }
 789
 790        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 791        self.input_chunk.text = suffix;
 792        Some(Chunk {
 793            text: prefix,
 794            ..self.input_chunk
 795        })
 796    }
 797}
 798
 799impl<'a> Iterator for WrapBufferRows<'a> {
 800    type Item = Option<u32>;
 801
 802    fn next(&mut self) -> Option<Self::Item> {
 803        if self.output_row > self.max_output_row {
 804            return None;
 805        }
 806
 807        let buffer_row = self.input_buffer_row;
 808        let soft_wrapped = self.soft_wrapped;
 809
 810        self.output_row += 1;
 811        self.transforms
 812            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 813        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 814            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 815            self.soft_wrapped = false;
 816        } else {
 817            self.soft_wrapped = true;
 818        }
 819
 820        Some(if soft_wrapped { None } else { Some(buffer_row) })
 821    }
 822}
 823
 824impl Transform {
 825    fn isomorphic(summary: TextSummary) -> Self {
 826        #[cfg(test)]
 827        assert!(!summary.lines.is_zero());
 828
 829        Self {
 830            summary: TransformSummary {
 831                input: summary.clone(),
 832                output: summary,
 833            },
 834            display_text: None,
 835        }
 836    }
 837
 838    fn wrap(indent: u32) -> Self {
 839        lazy_static! {
 840            static ref WRAP_TEXT: String = {
 841                let mut wrap_text = String::new();
 842                wrap_text.push('\n');
 843                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 844                wrap_text
 845            };
 846        }
 847
 848        Self {
 849            summary: TransformSummary {
 850                input: TextSummary::default(),
 851                output: TextSummary {
 852                    lines: Point::new(1, indent),
 853                    first_line_chars: 0,
 854                    last_line_chars: indent,
 855                    longest_row: 1,
 856                    longest_row_chars: indent,
 857                },
 858            },
 859            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 860        }
 861    }
 862
 863    fn is_isomorphic(&self) -> bool {
 864        self.display_text.is_none()
 865    }
 866}
 867
 868impl sum_tree::Item for Transform {
 869    type Summary = TransformSummary;
 870
 871    fn summary(&self) -> Self::Summary {
 872        self.summary.clone()
 873    }
 874}
 875
 876fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 877    if let Some(last_transform) = transforms.last_mut() {
 878        if last_transform.is_isomorphic() {
 879            last_transform.summary.input += &summary;
 880            last_transform.summary.output += &summary;
 881            return;
 882        }
 883    }
 884    transforms.push(Transform::isomorphic(summary));
 885}
 886
 887trait SumTreeExt {
 888    fn push_or_extend(&mut self, transform: Transform);
 889}
 890
 891impl SumTreeExt for SumTree<Transform> {
 892    fn push_or_extend(&mut self, transform: Transform) {
 893        let mut transform = Some(transform);
 894        self.update_last(
 895            |last_transform| {
 896                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 897                    let transform = transform.take().unwrap();
 898                    last_transform.summary.input += &transform.summary.input;
 899                    last_transform.summary.output += &transform.summary.output;
 900                }
 901            },
 902            &(),
 903        );
 904
 905        if let Some(transform) = transform {
 906            self.push(transform, &());
 907        }
 908    }
 909}
 910
 911impl WrapPoint {
 912    pub fn new(row: u32, column: u32) -> Self {
 913        Self(super::Point::new(row, column))
 914    }
 915
 916    pub fn row(self) -> u32 {
 917        self.0.row
 918    }
 919
 920    pub fn row_mut(&mut self) -> &mut u32 {
 921        &mut self.0.row
 922    }
 923
 924    pub fn column(&self) -> u32 {
 925        self.0.column
 926    }
 927
 928    pub fn column_mut(&mut self) -> &mut u32 {
 929        &mut self.0.column
 930    }
 931}
 932
 933impl sum_tree::Summary for TransformSummary {
 934    type Context = ();
 935
 936    fn add_summary(&mut self, other: &Self, _: &()) {
 937        self.input += &other.input;
 938        self.output += &other.output;
 939    }
 940}
 941
 942impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
 943    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 944        self.0 += summary.input.lines;
 945    }
 946}
 947
 948impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
 949    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
 950        Ord::cmp(&self.0, &cursor_location.input.lines)
 951    }
 952}
 953
 954impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
 955    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 956        self.0 += summary.output.lines;
 957    }
 958}
 959
 960fn consolidate_wrap_edits(edits: &mut Vec<WrapEdit>) {
 961    let mut i = 1;
 962    while i < edits.len() {
 963        let edit = edits[i].clone();
 964        let prev_edit = &mut edits[i - 1];
 965        if prev_edit.old.end >= edit.old.start {
 966            prev_edit.old.end = edit.old.end;
 967            prev_edit.new.end = edit.new.end;
 968            edits.remove(i);
 969            continue;
 970        }
 971        i += 1;
 972    }
 973}
 974
 975#[cfg(test)]
 976mod tests {
 977    use super::*;
 978    use crate::{
 979        display_map::{fold_map::FoldMap, tab_map::TabMap},
 980        test::Observer,
 981        MultiBuffer,
 982    };
 983    use language::RandomCharIter;
 984    use rand::prelude::*;
 985    use std::{cmp, env};
 986    use text::Rope;
 987
 988    #[gpui::test(iterations = 100)]
 989    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
 990        cx.foreground().set_block_on_ticks(0..=50);
 991        cx.foreground().forbid_parking();
 992        let operations = env::var("OPERATIONS")
 993            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
 994            .unwrap_or(10);
 995
 996        let font_cache = cx.font_cache().clone();
 997        let font_system = cx.platform().fonts();
 998        let mut wrap_width = if rng.gen_bool(0.1) {
 999            None
1000        } else {
1001            Some(rng.gen_range(0.0..=1000.0))
1002        };
1003        let tab_size = rng.gen_range(1..=4);
1004        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1005        let font_id = font_cache
1006            .select_font(family_id, &Default::default())
1007            .unwrap();
1008        let font_size = 14.0;
1009
1010        log::info!("Tab size: {}", tab_size);
1011        log::info!("Wrap width: {:?}", wrap_width);
1012
1013        let buffer = cx.update(|cx| {
1014            if rng.gen() {
1015                MultiBuffer::build_random(rng.gen_range(1..=5), &mut rng, cx)
1016            } else {
1017                let len = rng.gen_range(0..10);
1018                let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1019                MultiBuffer::build_simple(&text, cx)
1020            }
1021        });
1022        let mut buffer_snapshot = buffer.read_with(&cx, |buffer, cx| buffer.snapshot(cx));
1023        let (mut fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1024        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1025        log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1026        log::info!(
1027            "Unwrapped text (unexpanded tabs): {:?}",
1028            folds_snapshot.text()
1029        );
1030        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1031
1032        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1033        let unwrapped_text = tabs_snapshot.text();
1034        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1035
1036        let (wrap_map, _) =
1037            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1038        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
1039
1040        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1041            notifications.recv().await.unwrap();
1042        }
1043
1044        let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1045            assert!(!map.is_rewrapping());
1046            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1047        });
1048
1049        let actual_text = initial_snapshot.text();
1050        assert_eq!(
1051            actual_text, expected_text,
1052            "unwrapped text is: {:?}",
1053            unwrapped_text
1054        );
1055        log::info!("Wrapped text: {:?}", actual_text);
1056
1057        let mut edits = Vec::new();
1058        for _i in 0..operations {
1059            log::info!("{} ==============================================", _i);
1060
1061            let mut buffer_edits = Vec::new();
1062            match rng.gen_range(0..=100) {
1063                0..=19 => {
1064                    wrap_width = if rng.gen_bool(0.2) {
1065                        None
1066                    } else {
1067                        Some(rng.gen_range(0.0..=1000.0))
1068                    };
1069                    log::info!("Setting wrap width to {:?}", wrap_width);
1070                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1071                }
1072                20..=39 => {
1073                    for (folds_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1074                        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1075                        let (mut snapshot, wrap_edits) = wrap_map
1076                            .update(&mut cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1077                        snapshot.check_invariants();
1078                        snapshot.verify_chunks(&mut rng);
1079                        edits.push((snapshot, wrap_edits));
1080                    }
1081                }
1082                _ => {
1083                    buffer.update(&mut cx, |buffer, cx| {
1084                        let subscription = buffer.subscribe();
1085                        let edit_count = rng.gen_range(1..=5);
1086                        buffer.randomly_edit(&mut rng, edit_count, cx);
1087                        buffer_snapshot = buffer.snapshot(cx);
1088                        buffer_edits.extend(subscription.consume());
1089                    });
1090                }
1091            }
1092
1093            log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1094            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1095            log::info!(
1096                "Unwrapped text (unexpanded tabs): {:?}",
1097                folds_snapshot.text()
1098            );
1099            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1100            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1101
1102            let unwrapped_text = tabs_snapshot.text();
1103            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1104            let (mut snapshot, wrap_edits) = wrap_map.update(&mut cx, |map, cx| {
1105                map.sync(tabs_snapshot.clone(), tab_edits, cx)
1106            });
1107            snapshot.check_invariants();
1108            snapshot.verify_chunks(&mut rng);
1109            edits.push((snapshot, wrap_edits));
1110
1111            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1112                log::info!("Waiting for wrapping to finish");
1113                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1114                    notifications.recv().await.unwrap();
1115                }
1116                wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1117            }
1118
1119            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1120                let (mut wrapped_snapshot, wrap_edits) =
1121                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1122                let actual_text = wrapped_snapshot.text();
1123                let actual_longest_row = wrapped_snapshot.longest_row();
1124                log::info!("Wrapping finished: {:?}", actual_text);
1125                wrapped_snapshot.check_invariants();
1126                wrapped_snapshot.verify_chunks(&mut rng);
1127                edits.push((wrapped_snapshot.clone(), wrap_edits));
1128                assert_eq!(
1129                    actual_text, expected_text,
1130                    "unwrapped text is: {:?}",
1131                    unwrapped_text
1132                );
1133
1134                let mut summary = TextSummary::default();
1135                for (ix, item) in wrapped_snapshot
1136                    .transforms
1137                    .items(&())
1138                    .into_iter()
1139                    .enumerate()
1140                {
1141                    summary += &item.summary.output;
1142                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1143                }
1144
1145                if tab_size == 1
1146                    || !wrapped_snapshot
1147                        .tab_snapshot
1148                        .fold_snapshot
1149                        .text()
1150                        .contains('\t')
1151                {
1152                    let mut expected_longest_rows = Vec::new();
1153                    let mut longest_line_len = -1;
1154                    for (row, line) in expected_text.split('\n').enumerate() {
1155                        let line_char_count = line.chars().count() as isize;
1156                        if line_char_count > longest_line_len {
1157                            expected_longest_rows.clear();
1158                            longest_line_len = line_char_count;
1159                        }
1160                        if line_char_count >= longest_line_len {
1161                            expected_longest_rows.push(row as u32);
1162                        }
1163                    }
1164
1165                    assert!(
1166                        expected_longest_rows.contains(&actual_longest_row),
1167                        "incorrect longest row {}. expected {:?} with length {}",
1168                        actual_longest_row,
1169                        expected_longest_rows,
1170                        longest_line_len,
1171                    )
1172                }
1173            }
1174        }
1175
1176        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1177        for (snapshot, patch) in edits {
1178            let snapshot_text = Rope::from(snapshot.text().as_str());
1179            for edit in &patch {
1180                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1181                let old_end = initial_text.point_to_offset(cmp::min(
1182                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1183                    initial_text.max_point(),
1184                ));
1185                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1186                let new_end = snapshot_text.point_to_offset(cmp::min(
1187                    Point::new(edit.new.end, 0),
1188                    snapshot_text.max_point(),
1189                ));
1190                let new_text = snapshot_text
1191                    .chunks_in_range(new_start..new_end)
1192                    .collect::<String>();
1193
1194                initial_text.replace(old_start..old_end, &new_text);
1195            }
1196            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1197        }
1198
1199        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1200            log::info!("Waiting for wrapping to finish");
1201            while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1202                notifications.recv().await.unwrap();
1203            }
1204        }
1205        wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1206    }
1207
1208    fn wrap_text(
1209        unwrapped_text: &str,
1210        wrap_width: Option<f32>,
1211        line_wrapper: &mut LineWrapper,
1212    ) -> String {
1213        if let Some(wrap_width) = wrap_width {
1214            let mut wrapped_text = String::new();
1215            for (row, line) in unwrapped_text.split('\n').enumerate() {
1216                if row > 0 {
1217                    wrapped_text.push('\n')
1218                }
1219
1220                let mut prev_ix = 0;
1221                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1222                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1223                    wrapped_text.push('\n');
1224                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1225                    prev_ix = boundary.ix;
1226                }
1227                wrapped_text.push_str(&line[prev_ix..]);
1228            }
1229            wrapped_text
1230        } else {
1231            unwrapped_text.to_string()
1232        }
1233    }
1234
1235    impl WrapSnapshot {
1236        pub fn text(&self) -> String {
1237            self.text_chunks(0).collect()
1238        }
1239
1240        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1241            for _ in 0..5 {
1242                let mut end_row = rng.gen_range(0..=self.max_point().row());
1243                let start_row = rng.gen_range(0..=end_row);
1244                end_row += 1;
1245
1246                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1247                if expected_text.ends_with("\n") {
1248                    expected_text.push('\n');
1249                }
1250                let mut expected_text = expected_text
1251                    .lines()
1252                    .take((end_row - start_row) as usize)
1253                    .collect::<Vec<_>>()
1254                    .join("\n");
1255                if end_row <= self.max_point().row() {
1256                    expected_text.push('\n');
1257                }
1258
1259                let actual_text = self
1260                    .chunks(start_row..end_row, None)
1261                    .map(|c| c.text)
1262                    .collect::<String>();
1263                assert_eq!(
1264                    expected_text,
1265                    actual_text,
1266                    "chunks != highlighted_chunks for rows {:?}",
1267                    start_row..end_row
1268                );
1269            }
1270        }
1271    }
1272}