wrap_map.rs

   1use super::{
   2    fold_map,
   3    tab_map::{self, Edit as TabEdit, Snapshot as TabSnapshot, TabPoint},
   4    DisplayRow,
   5};
   6use gpui::{
   7    fonts::FontId, text_layout::LineWrapper, Entity, ModelContext, ModelHandle, MutableAppContext,
   8    Task,
   9};
  10use language::{Chunk, Point};
  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 Edit = text::Edit<u32>;
  20
  21pub struct WrapMap {
  22    snapshot: Snapshot,
  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 Snapshot {
  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 Chunks<'a> {
  58    input_chunks: tab_map::Chunks<'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 BufferRows<'a> {
  66    input_buffer_rows: fold_map::BufferRows<'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>, Snapshot) {
  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: Snapshot::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    ) -> (Snapshot, Vec<Edit>) {
 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_lines: range.clone(),
 162                            new_lines: 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![Edit {
 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 Snapshot {
 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    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, tab_edits: &[TabEdit]) -> Patch<u32> {
 310        let mut new_transforms;
 311        if tab_edits.is_empty() {
 312            new_transforms = self.transforms.clone();
 313        } else {
 314            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 315
 316            let mut tab_edits_iter = tab_edits.iter().peekable();
 317            new_transforms = old_cursor.slice(
 318                &tab_edits_iter.peek().unwrap().old_lines.start,
 319                Bias::Right,
 320                &(),
 321            );
 322
 323            while let Some(edit) = tab_edits_iter.next() {
 324                if edit.new_lines.start > TabPoint::from(new_transforms.summary().input.lines) {
 325                    let summary = new_tab_snapshot.text_summary_for_range(
 326                        TabPoint::from(new_transforms.summary().input.lines)..edit.new_lines.start,
 327                    );
 328                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 329                }
 330
 331                if !edit.new_lines.is_empty() {
 332                    new_transforms.push_or_extend(Transform::isomorphic(
 333                        new_tab_snapshot.text_summary_for_range(edit.new_lines.clone()),
 334                    ));
 335                }
 336
 337                old_cursor.seek_forward(&edit.old_lines.end, Bias::Right, &());
 338                if let Some(next_edit) = tab_edits_iter.peek() {
 339                    if next_edit.old_lines.start > old_cursor.end(&()) {
 340                        if old_cursor.end(&()) > edit.old_lines.end {
 341                            let summary = self
 342                                .tab_snapshot
 343                                .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 344                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 345                        }
 346
 347                        old_cursor.next(&());
 348                        new_transforms.push_tree(
 349                            old_cursor.slice(&next_edit.old_lines.start, Bias::Right, &()),
 350                            &(),
 351                        );
 352                    }
 353                } else {
 354                    if old_cursor.end(&()) > edit.old_lines.end {
 355                        let summary = self
 356                            .tab_snapshot
 357                            .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 358                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 359                    }
 360                    old_cursor.next(&());
 361                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 362                }
 363            }
 364        }
 365
 366        let old_snapshot = mem::replace(
 367            self,
 368            Snapshot {
 369                tab_snapshot: new_tab_snapshot,
 370                transforms: new_transforms,
 371                interpolated: true,
 372            },
 373        );
 374        self.check_invariants();
 375        old_snapshot.compute_edits(tab_edits, self)
 376    }
 377
 378    async fn update(
 379        &mut self,
 380        new_tab_snapshot: TabSnapshot,
 381        tab_edits: &[TabEdit],
 382        wrap_width: f32,
 383        line_wrapper: &mut LineWrapper,
 384    ) -> Patch<u32> {
 385        #[derive(Debug)]
 386        struct RowEdit {
 387            old_rows: Range<u32>,
 388            new_rows: Range<u32>,
 389        }
 390
 391        let mut tab_edits_iter = tab_edits.into_iter().peekable();
 392        let mut row_edits = Vec::new();
 393        while let Some(edit) = tab_edits_iter.next() {
 394            let mut row_edit = RowEdit {
 395                old_rows: edit.old_lines.start.row()..edit.old_lines.end.row() + 1,
 396                new_rows: edit.new_lines.start.row()..edit.new_lines.end.row() + 1,
 397            };
 398
 399            while let Some(next_edit) = tab_edits_iter.peek() {
 400                if next_edit.old_lines.start.row() <= row_edit.old_rows.end {
 401                    row_edit.old_rows.end = next_edit.old_lines.end.row() + 1;
 402                    row_edit.new_rows.end = next_edit.new_lines.end.row() + 1;
 403                    tab_edits_iter.next();
 404                } else {
 405                    break;
 406                }
 407            }
 408
 409            row_edits.push(row_edit);
 410        }
 411
 412        let mut new_transforms;
 413        if row_edits.is_empty() {
 414            new_transforms = self.transforms.clone();
 415        } else {
 416            let mut row_edits = row_edits.into_iter().peekable();
 417            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 418
 419            new_transforms = old_cursor.slice(
 420                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 421                Bias::Right,
 422                &(),
 423            );
 424
 425            while let Some(edit) = row_edits.next() {
 426                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 427                    let summary = new_tab_snapshot.text_summary_for_range(
 428                        TabPoint(new_transforms.summary().input.lines)
 429                            ..TabPoint::new(edit.new_rows.start, 0),
 430                    );
 431                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 432                }
 433
 434                let mut line = String::new();
 435                let mut remaining = None;
 436                let mut chunks = new_tab_snapshot.chunks(
 437                    TabPoint::new(edit.new_rows.start, 0)..new_tab_snapshot.max_point(),
 438                    None,
 439                );
 440                let mut edit_transforms = Vec::<Transform>::new();
 441                for _ in edit.new_rows.start..edit.new_rows.end {
 442                    while let Some(chunk) =
 443                        remaining.take().or_else(|| chunks.next().map(|c| c.text))
 444                    {
 445                        if let Some(ix) = chunk.find('\n') {
 446                            line.push_str(&chunk[..ix + 1]);
 447                            remaining = Some(&chunk[ix + 1..]);
 448                            break;
 449                        } else {
 450                            line.push_str(chunk)
 451                        }
 452                    }
 453
 454                    if line.is_empty() {
 455                        break;
 456                    }
 457
 458                    let mut prev_boundary_ix = 0;
 459                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 460                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 461                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 462                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 463                        prev_boundary_ix = boundary.ix;
 464                    }
 465
 466                    if prev_boundary_ix < line.len() {
 467                        push_isomorphic(
 468                            &mut edit_transforms,
 469                            TextSummary::from(&line[prev_boundary_ix..]),
 470                        );
 471                    }
 472
 473                    line.clear();
 474                    yield_now().await;
 475                }
 476
 477                let mut edit_transforms = edit_transforms.into_iter();
 478                if let Some(transform) = edit_transforms.next() {
 479                    new_transforms.push_or_extend(transform);
 480                }
 481                new_transforms.extend(edit_transforms, &());
 482
 483                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 484                if let Some(next_edit) = row_edits.peek() {
 485                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 486                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 487                            let summary = self.tab_snapshot.text_summary_for_range(
 488                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 489                            );
 490                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 491                        }
 492                        old_cursor.next(&());
 493                        new_transforms.push_tree(
 494                            old_cursor.slice(
 495                                &TabPoint::new(next_edit.old_rows.start, 0),
 496                                Bias::Right,
 497                                &(),
 498                            ),
 499                            &(),
 500                        );
 501                    }
 502                } else {
 503                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 504                        let summary = self.tab_snapshot.text_summary_for_range(
 505                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 506                        );
 507                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 508                    }
 509                    old_cursor.next(&());
 510                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 511                }
 512            }
 513        }
 514
 515        let old_snapshot = mem::replace(
 516            self,
 517            Snapshot {
 518                tab_snapshot: new_tab_snapshot,
 519                transforms: new_transforms,
 520                interpolated: false,
 521            },
 522        );
 523        self.check_invariants();
 524        old_snapshot.compute_edits(tab_edits, self)
 525    }
 526
 527    fn compute_edits(&self, tab_edits: &[TabEdit], new_snapshot: &Snapshot) -> Patch<u32> {
 528        let mut wrap_edits = Vec::new();
 529        let mut old_cursor = self.transforms.cursor::<TransformSummary>();
 530        let mut new_cursor = new_snapshot.transforms.cursor::<TransformSummary>();
 531        for mut tab_edit in tab_edits.iter().cloned() {
 532            tab_edit.old_lines.start.0.column = 0;
 533            tab_edit.old_lines.end.0 += Point::new(1, 0);
 534            tab_edit.new_lines.start.0.column = 0;
 535            tab_edit.new_lines.end.0 += Point::new(1, 0);
 536
 537            old_cursor.seek(&tab_edit.old_lines.start, Bias::Right, &());
 538            let mut old_start = old_cursor.start().output.lines;
 539            old_start += tab_edit.old_lines.start.0 - old_cursor.start().input.lines;
 540
 541            old_cursor.seek(&tab_edit.old_lines.end, Bias::Right, &());
 542            let mut old_end = old_cursor.start().output.lines;
 543            old_end += tab_edit.old_lines.end.0 - old_cursor.start().input.lines;
 544
 545            new_cursor.seek(&tab_edit.new_lines.start, Bias::Right, &());
 546            let mut new_start = new_cursor.start().output.lines;
 547            new_start += tab_edit.new_lines.start.0 - new_cursor.start().input.lines;
 548
 549            new_cursor.seek(&tab_edit.new_lines.end, Bias::Right, &());
 550            let mut new_end = new_cursor.start().output.lines;
 551            new_end += tab_edit.new_lines.end.0 - new_cursor.start().input.lines;
 552
 553            wrap_edits.push(Edit {
 554                old: old_start.row..old_end.row,
 555                new: new_start.row..new_end.row,
 556            });
 557        }
 558
 559        consolidate_wrap_edits(&mut wrap_edits);
 560        Patch::new(wrap_edits)
 561    }
 562
 563    pub fn text_chunks(&self, wrap_row: u32) -> impl Iterator<Item = &str> {
 564        self.chunks(wrap_row..self.max_point().row() + 1, None)
 565            .map(|h| h.text)
 566    }
 567
 568    pub fn chunks<'a>(&'a self, rows: Range<u32>, theme: Option<&'a SyntaxTheme>) -> Chunks<'a> {
 569        let output_start = WrapPoint::new(rows.start, 0);
 570        let output_end = WrapPoint::new(rows.end, 0);
 571        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 572        transforms.seek(&output_start, Bias::Right, &());
 573        let mut input_start = TabPoint(transforms.start().1 .0);
 574        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 575            input_start.0 += output_start.0 - transforms.start().0 .0;
 576        }
 577        let input_end = self
 578            .to_tab_point(output_end)
 579            .min(self.tab_snapshot.max_point());
 580        Chunks {
 581            input_chunks: self.tab_snapshot.chunks(input_start..input_end, theme),
 582            input_chunk: Default::default(),
 583            output_position: output_start,
 584            max_output_row: rows.end,
 585            transforms,
 586        }
 587    }
 588
 589    pub fn text_summary(&self) -> TextSummary {
 590        self.transforms.summary().output
 591    }
 592
 593    pub fn max_point(&self) -> WrapPoint {
 594        WrapPoint(self.transforms.summary().output.lines)
 595    }
 596
 597    pub fn line_len(&self, row: u32) -> u32 {
 598        let mut len = 0;
 599        for chunk in self.text_chunks(row) {
 600            if let Some(newline_ix) = chunk.find('\n') {
 601                len += newline_ix;
 602                break;
 603            } else {
 604                len += chunk.len();
 605            }
 606        }
 607        len as u32
 608    }
 609
 610    pub fn line_char_count(&self, row: u32) -> u32 {
 611        self.text_chunks(row)
 612            .flat_map(|c| c.chars())
 613            .take_while(|c| *c != '\n')
 614            .count() as u32
 615    }
 616
 617    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 618        let mut cursor = self.transforms.cursor::<WrapPoint>();
 619        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 620        cursor.item().and_then(|transform| {
 621            if transform.is_isomorphic() {
 622                None
 623            } else {
 624                Some(transform.summary.output.lines.column)
 625            }
 626        })
 627    }
 628
 629    pub fn longest_row(&self) -> u32 {
 630        self.transforms.summary().output.longest_row
 631    }
 632
 633    pub fn buffer_rows(&self, start_row: u32) -> BufferRows {
 634        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 635        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 636        let mut input_row = transforms.start().1.row();
 637        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 638            input_row += start_row - transforms.start().0.row();
 639        }
 640        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 641        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 642        let input_buffer_row = input_buffer_rows.next().unwrap();
 643        BufferRows {
 644            transforms,
 645            input_buffer_row,
 646            input_buffer_rows,
 647            output_row: start_row,
 648            soft_wrapped,
 649            max_output_row: self.max_point().row(),
 650        }
 651    }
 652
 653    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 654        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 655        cursor.seek(&point, Bias::Right, &());
 656        let mut tab_point = cursor.start().1 .0;
 657        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 658            tab_point += point.0 - cursor.start().0 .0;
 659        }
 660        TabPoint(tab_point)
 661    }
 662
 663    pub fn to_point(&self, point: WrapPoint, bias: Bias) -> Point {
 664        self.tab_snapshot.to_point(self.to_tab_point(point), bias)
 665    }
 666
 667    pub fn from_point(&self, point: Point, bias: Bias) -> WrapPoint {
 668        self.from_tab_point(self.tab_snapshot.from_point(point, bias))
 669    }
 670
 671    pub fn from_tab_point(&self, point: TabPoint) -> WrapPoint {
 672        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 673        cursor.seek(&point, Bias::Right, &());
 674        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 675    }
 676
 677    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 678        if bias == Bias::Left {
 679            let mut cursor = self.transforms.cursor::<WrapPoint>();
 680            cursor.seek(&point, Bias::Right, &());
 681            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 682                point = *cursor.start();
 683                *point.column_mut() -= 1;
 684            }
 685        }
 686
 687        self.from_tab_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 688    }
 689
 690    fn check_invariants(&self) {
 691        #[cfg(test)]
 692        {
 693            assert_eq!(
 694                TabPoint::from(self.transforms.summary().input.lines),
 695                self.tab_snapshot.max_point()
 696            );
 697
 698            {
 699                let mut transforms = self.transforms.cursor::<()>().peekable();
 700                while let Some(transform) = transforms.next() {
 701                    if let Some(next_transform) = transforms.peek() {
 702                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 703                    }
 704                }
 705            }
 706
 707            let mut expected_buffer_rows = Vec::new();
 708            let mut buffer_row = 0;
 709            let mut prev_tab_row = 0;
 710            for display_row in 0..=self.max_point().row() {
 711                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 712                let soft_wrapped;
 713                if tab_point.row() == prev_tab_row {
 714                    soft_wrapped = display_row != 0;
 715                } else {
 716                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 717                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 718                    buffer_row = buffer_point.row;
 719                    prev_tab_row = tab_point.row();
 720                    soft_wrapped = false;
 721                }
 722                expected_buffer_rows.push(if soft_wrapped {
 723                    DisplayRow::Wrap
 724                } else {
 725                    DisplayRow::Buffer(buffer_row)
 726                });
 727            }
 728
 729            for start_display_row in 0..expected_buffer_rows.len() {
 730                assert_eq!(
 731                    self.buffer_rows(start_display_row as u32)
 732                        .collect::<Vec<_>>(),
 733                    &expected_buffer_rows[start_display_row..],
 734                    "invalid buffer_rows({}..)",
 735                    start_display_row
 736                );
 737            }
 738        }
 739    }
 740}
 741
 742impl<'a> Iterator for Chunks<'a> {
 743    type Item = Chunk<'a>;
 744
 745    fn next(&mut self) -> Option<Self::Item> {
 746        if self.output_position.row() >= self.max_output_row {
 747            return None;
 748        }
 749
 750        let transform = self.transforms.item()?;
 751        if let Some(display_text) = transform.display_text {
 752            let mut start_ix = 0;
 753            let mut end_ix = display_text.len();
 754            let mut summary = transform.summary.output.lines;
 755
 756            if self.output_position > self.transforms.start().0 {
 757                // Exclude newline starting prior to the desired row.
 758                start_ix = 1;
 759                summary.row = 0;
 760            } else if self.output_position.row() + 1 >= self.max_output_row {
 761                // Exclude soft indentation ending after the desired row.
 762                end_ix = 1;
 763                summary.column = 0;
 764            }
 765
 766            self.output_position.0 += summary;
 767            self.transforms.next(&());
 768            return Some(Chunk {
 769                text: &display_text[start_ix..end_ix],
 770                ..self.input_chunk
 771            });
 772        }
 773
 774        if self.input_chunk.text.is_empty() {
 775            self.input_chunk = self.input_chunks.next().unwrap();
 776        }
 777
 778        let mut input_len = 0;
 779        let transform_end = self.transforms.end(&()).0;
 780        for c in self.input_chunk.text.chars() {
 781            let char_len = c.len_utf8();
 782            input_len += char_len;
 783            if c == '\n' {
 784                *self.output_position.row_mut() += 1;
 785                *self.output_position.column_mut() = 0;
 786            } else {
 787                *self.output_position.column_mut() += char_len as u32;
 788            }
 789
 790            if self.output_position >= transform_end {
 791                self.transforms.next(&());
 792                break;
 793            }
 794        }
 795
 796        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 797        self.input_chunk.text = suffix;
 798        Some(Chunk {
 799            text: prefix,
 800            ..self.input_chunk
 801        })
 802    }
 803}
 804
 805impl<'a> Iterator for BufferRows<'a> {
 806    type Item = DisplayRow;
 807
 808    fn next(&mut self) -> Option<Self::Item> {
 809        if self.output_row > self.max_output_row {
 810            return None;
 811        }
 812
 813        let buffer_row = self.input_buffer_row;
 814        let soft_wrapped = self.soft_wrapped;
 815
 816        self.output_row += 1;
 817        self.transforms
 818            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 819        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 820            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 821            self.soft_wrapped = false;
 822        } else {
 823            self.soft_wrapped = true;
 824        }
 825
 826        Some(if soft_wrapped {
 827            DisplayRow::Wrap
 828        } else {
 829            DisplayRow::Buffer(buffer_row)
 830        })
 831    }
 832}
 833
 834impl Transform {
 835    fn isomorphic(summary: TextSummary) -> Self {
 836        #[cfg(test)]
 837        assert!(!summary.lines.is_zero());
 838
 839        Self {
 840            summary: TransformSummary {
 841                input: summary.clone(),
 842                output: summary,
 843            },
 844            display_text: None,
 845        }
 846    }
 847
 848    fn wrap(indent: u32) -> Self {
 849        lazy_static! {
 850            static ref WRAP_TEXT: String = {
 851                let mut wrap_text = String::new();
 852                wrap_text.push('\n');
 853                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 854                wrap_text
 855            };
 856        }
 857
 858        Self {
 859            summary: TransformSummary {
 860                input: TextSummary::default(),
 861                output: TextSummary {
 862                    lines: Point::new(1, indent),
 863                    first_line_chars: 0,
 864                    last_line_chars: indent,
 865                    longest_row: 1,
 866                    longest_row_chars: indent,
 867                },
 868            },
 869            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 870        }
 871    }
 872
 873    fn is_isomorphic(&self) -> bool {
 874        self.display_text.is_none()
 875    }
 876}
 877
 878impl sum_tree::Item for Transform {
 879    type Summary = TransformSummary;
 880
 881    fn summary(&self) -> Self::Summary {
 882        self.summary.clone()
 883    }
 884}
 885
 886fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 887    if let Some(last_transform) = transforms.last_mut() {
 888        if last_transform.is_isomorphic() {
 889            last_transform.summary.input += &summary;
 890            last_transform.summary.output += &summary;
 891            return;
 892        }
 893    }
 894    transforms.push(Transform::isomorphic(summary));
 895}
 896
 897trait SumTreeExt {
 898    fn push_or_extend(&mut self, transform: Transform);
 899}
 900
 901impl SumTreeExt for SumTree<Transform> {
 902    fn push_or_extend(&mut self, transform: Transform) {
 903        let mut transform = Some(transform);
 904        self.update_last(
 905            |last_transform| {
 906                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
 907                    let transform = transform.take().unwrap();
 908                    last_transform.summary.input += &transform.summary.input;
 909                    last_transform.summary.output += &transform.summary.output;
 910                }
 911            },
 912            &(),
 913        );
 914
 915        if let Some(transform) = transform {
 916            self.push(transform, &());
 917        }
 918    }
 919}
 920
 921impl WrapPoint {
 922    pub fn new(row: u32, column: u32) -> Self {
 923        Self(super::Point::new(row, column))
 924    }
 925
 926    pub fn row(self) -> u32 {
 927        self.0.row
 928    }
 929
 930    pub fn row_mut(&mut self) -> &mut u32 {
 931        &mut self.0.row
 932    }
 933
 934    pub fn column(&self) -> u32 {
 935        self.0.column
 936    }
 937
 938    pub fn column_mut(&mut self) -> &mut u32 {
 939        &mut self.0.column
 940    }
 941}
 942
 943impl sum_tree::Summary for TransformSummary {
 944    type Context = ();
 945
 946    fn add_summary(&mut self, other: &Self, _: &()) {
 947        self.input += &other.input;
 948        self.output += &other.output;
 949    }
 950}
 951
 952impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
 953    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 954        self.0 += summary.input.lines;
 955    }
 956}
 957
 958impl<'a> sum_tree::SeekTarget<'a, TransformSummary, TransformSummary> for TabPoint {
 959    fn cmp(&self, cursor_location: &TransformSummary, _: &()) -> std::cmp::Ordering {
 960        Ord::cmp(&self.0, &cursor_location.input.lines)
 961    }
 962}
 963
 964impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
 965    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 966        self.0 += summary.output.lines;
 967    }
 968}
 969
 970fn consolidate_wrap_edits(edits: &mut Vec<Edit>) {
 971    let mut i = 1;
 972    while i < edits.len() {
 973        let edit = edits[i].clone();
 974        let prev_edit = &mut edits[i - 1];
 975        if prev_edit.old.end >= edit.old.start {
 976            prev_edit.old.end = edit.old.end;
 977            prev_edit.new.end = edit.new.end;
 978            edits.remove(i);
 979            continue;
 980        }
 981        i += 1;
 982    }
 983}
 984
 985#[cfg(test)]
 986mod tests {
 987    use super::*;
 988    use crate::{
 989        display_map::{fold_map::FoldMap, tab_map::TabMap},
 990        test::Observer,
 991    };
 992    use language::{Buffer, RandomCharIter};
 993    use rand::prelude::*;
 994    use std::{cmp, env};
 995    use text::Rope;
 996
 997    #[gpui::test(iterations = 100)]
 998    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
 999        cx.foreground().set_block_on_ticks(0..=50);
1000        cx.foreground().forbid_parking();
1001        let operations = env::var("OPERATIONS")
1002            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1003            .unwrap_or(10);
1004
1005        let font_cache = cx.font_cache().clone();
1006        let font_system = cx.platform().fonts();
1007        let mut wrap_width = if rng.gen_bool(0.1) {
1008            None
1009        } else {
1010            Some(rng.gen_range(0.0..=1000.0))
1011        };
1012        let tab_size = rng.gen_range(1..=4);
1013        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1014        let font_id = font_cache
1015            .select_font(family_id, &Default::default())
1016            .unwrap();
1017        let font_size = 14.0;
1018
1019        log::info!("Tab size: {}", tab_size);
1020        log::info!("Wrap width: {:?}", wrap_width);
1021
1022        let buffer = cx.add_model(|cx| {
1023            let len = rng.gen_range(0..10);
1024            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1025            Buffer::new(0, text, cx)
1026        });
1027        let buffer_snapshot = buffer.read_with(&cx, |buffer, _| buffer.snapshot());
1028        let (mut fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1029        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1030        log::info!(
1031            "Unwrapped text (no folds): {:?}",
1032            buffer.read_with(&cx, |buf, _| buf.text())
1033        );
1034        log::info!(
1035            "Unwrapped text (unexpanded tabs): {:?}",
1036            folds_snapshot.text()
1037        );
1038        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1039
1040        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1041        let unwrapped_text = tabs_snapshot.text();
1042        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1043
1044        let (wrap_map, _) =
1045            cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
1046        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
1047
1048        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1049            notifications.recv().await.unwrap();
1050        }
1051
1052        let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1053            assert!(!map.is_rewrapping());
1054            map.sync(tabs_snapshot.clone(), Vec::new(), cx)
1055        });
1056
1057        let actual_text = initial_snapshot.text();
1058        assert_eq!(
1059            actual_text, expected_text,
1060            "unwrapped text is: {:?}",
1061            unwrapped_text
1062        );
1063        log::info!("Wrapped text: {:?}", actual_text);
1064
1065        let mut edits = Vec::new();
1066        for _i in 0..operations {
1067            log::info!("{} ==============================================", _i);
1068
1069            let mut buffer_edits = Vec::new();
1070            match rng.gen_range(0..=100) {
1071                0..=19 => {
1072                    wrap_width = if rng.gen_bool(0.2) {
1073                        None
1074                    } else {
1075                        Some(rng.gen_range(0.0..=1000.0))
1076                    };
1077                    log::info!("Setting wrap width to {:?}", wrap_width);
1078                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1079                }
1080                20..=39 => {
1081                    for (folds_snapshot, fold_edits) in fold_map.randomly_mutate(&mut rng) {
1082                        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1083                        let (mut snapshot, wrap_edits) = wrap_map
1084                            .update(&mut cx, |map, cx| map.sync(tabs_snapshot, tab_edits, cx));
1085                        snapshot.check_invariants();
1086                        snapshot.verify_chunks(&mut rng);
1087                        edits.push((snapshot, wrap_edits));
1088                    }
1089                }
1090                _ => {
1091                    buffer.update(&mut cx, |buffer, cx| {
1092                        let v0 = buffer.version();
1093                        let edit_count = rng.gen_range(1..=5);
1094                        buffer.randomly_edit(&mut rng, edit_count, cx);
1095                        buffer_edits.extend(buffer.edits_since(&v0));
1096                    });
1097                }
1098            }
1099
1100            let buffer_snapshot = buffer.read_with(&cx, |buffer, _| buffer.snapshot());
1101            log::info!("Unwrapped text (no folds): {:?}", buffer_snapshot.text());
1102            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot, buffer_edits);
1103            log::info!(
1104                "Unwrapped text (unexpanded tabs): {:?}",
1105                folds_snapshot.text()
1106            );
1107            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1108            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1109
1110            let unwrapped_text = tabs_snapshot.text();
1111            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1112            let (mut snapshot, wrap_edits) = wrap_map.update(&mut cx, |map, cx| {
1113                map.sync(tabs_snapshot.clone(), tab_edits, cx)
1114            });
1115            snapshot.check_invariants();
1116            snapshot.verify_chunks(&mut rng);
1117            edits.push((snapshot, wrap_edits));
1118
1119            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1120                log::info!("Waiting for wrapping to finish");
1121                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1122                    notifications.recv().await.unwrap();
1123                }
1124                wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1125            }
1126
1127            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1128                let (mut wrapped_snapshot, wrap_edits) =
1129                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1130                let actual_text = wrapped_snapshot.text();
1131                let actual_longest_row = wrapped_snapshot.longest_row();
1132                log::info!("Wrapping finished: {:?}", actual_text);
1133                wrapped_snapshot.check_invariants();
1134                wrapped_snapshot.verify_chunks(&mut rng);
1135                edits.push((wrapped_snapshot.clone(), wrap_edits));
1136                assert_eq!(
1137                    actual_text, expected_text,
1138                    "unwrapped text is: {:?}",
1139                    unwrapped_text
1140                );
1141
1142                let mut summary = TextSummary::default();
1143                for (ix, item) in wrapped_snapshot
1144                    .transforms
1145                    .items(&())
1146                    .into_iter()
1147                    .enumerate()
1148                {
1149                    summary += &item.summary.output;
1150                    log::info!("{} summary: {:?}", ix, item.summary.output,);
1151                }
1152
1153                if tab_size == 1
1154                    || !wrapped_snapshot
1155                        .tab_snapshot
1156                        .fold_snapshot
1157                        .text()
1158                        .contains('\t')
1159                {
1160                    let mut expected_longest_rows = Vec::new();
1161                    let mut longest_line_len = -1;
1162                    for (row, line) in expected_text.split('\n').enumerate() {
1163                        let line_char_count = line.chars().count() as isize;
1164                        if line_char_count > longest_line_len {
1165                            expected_longest_rows.clear();
1166                            longest_line_len = line_char_count;
1167                        }
1168                        if line_char_count >= longest_line_len {
1169                            expected_longest_rows.push(row as u32);
1170                        }
1171                    }
1172
1173                    assert!(
1174                        expected_longest_rows.contains(&actual_longest_row),
1175                        "incorrect longest row {}. expected {:?} with length {}",
1176                        actual_longest_row,
1177                        expected_longest_rows,
1178                        longest_line_len,
1179                    )
1180                }
1181            }
1182        }
1183
1184        let mut initial_text = Rope::from(initial_snapshot.text().as_str());
1185        for (snapshot, patch) in edits {
1186            let snapshot_text = Rope::from(snapshot.text().as_str());
1187            for edit in &patch {
1188                let old_start = initial_text.point_to_offset(Point::new(edit.new.start, 0));
1189                let old_end = initial_text.point_to_offset(cmp::min(
1190                    Point::new(edit.new.start + edit.old.len() as u32, 0),
1191                    initial_text.max_point(),
1192                ));
1193                let new_start = snapshot_text.point_to_offset(Point::new(edit.new.start, 0));
1194                let new_end = snapshot_text.point_to_offset(cmp::min(
1195                    Point::new(edit.new.end, 0),
1196                    snapshot_text.max_point(),
1197                ));
1198                let new_text = snapshot_text
1199                    .chunks_in_range(new_start..new_end)
1200                    .collect::<String>();
1201
1202                initial_text.replace(old_start..old_end, &new_text);
1203            }
1204            assert_eq!(initial_text.to_string(), snapshot_text.to_string());
1205        }
1206
1207        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1208            log::info!("Waiting for wrapping to finish");
1209            while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1210                notifications.recv().await.unwrap();
1211            }
1212        }
1213        wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
1214    }
1215
1216    fn wrap_text(
1217        unwrapped_text: &str,
1218        wrap_width: Option<f32>,
1219        line_wrapper: &mut LineWrapper,
1220    ) -> String {
1221        if let Some(wrap_width) = wrap_width {
1222            let mut wrapped_text = String::new();
1223            for (row, line) in unwrapped_text.split('\n').enumerate() {
1224                if row > 0 {
1225                    wrapped_text.push('\n')
1226                }
1227
1228                let mut prev_ix = 0;
1229                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1230                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1231                    wrapped_text.push('\n');
1232                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1233                    prev_ix = boundary.ix;
1234                }
1235                wrapped_text.push_str(&line[prev_ix..]);
1236            }
1237            wrapped_text
1238        } else {
1239            unwrapped_text.to_string()
1240        }
1241    }
1242
1243    impl Snapshot {
1244        pub fn text(&self) -> String {
1245            self.text_chunks(0).collect()
1246        }
1247
1248        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1249            for _ in 0..5 {
1250                let mut end_row = rng.gen_range(0..=self.max_point().row());
1251                let start_row = rng.gen_range(0..=end_row);
1252                end_row += 1;
1253
1254                let mut expected_text = self.text_chunks(start_row).collect::<String>();
1255                if expected_text.ends_with("\n") {
1256                    expected_text.push('\n');
1257                }
1258                let mut expected_text = expected_text
1259                    .lines()
1260                    .take((end_row - start_row) as usize)
1261                    .collect::<Vec<_>>()
1262                    .join("\n");
1263                if end_row <= self.max_point().row() {
1264                    expected_text.push('\n');
1265                }
1266
1267                let actual_text = self
1268                    .chunks(start_row..end_row, None)
1269                    .map(|c| c.text)
1270                    .collect::<String>();
1271                assert_eq!(
1272                    expected_text,
1273                    actual_text,
1274                    "chunks != highlighted_chunks for rows {:?}",
1275                    start_row..end_row
1276                );
1277            }
1278        }
1279    }
1280}