wrap_map.rs

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