wrap_map.rs

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