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