wrap_map.rs

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