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, new: &Self) -> &mut Self {
 273        let mut new_edits = new.0.iter().peekable();
 274        let mut old_delta = 0;
 275        let mut new_delta = 0;
 276        let mut ix = 0;
 277        'outer: while ix < self.0.len() {
 278            let old_edit = &mut self.0[ix];
 279            old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
 280            old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
 281
 282            while let Some(new_edit) = new_edits.peek() {
 283                let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
 284                if new_edit.old.end < self.0[ix].new.start {
 285                    let new_edit = new_edits.next().unwrap().clone();
 286                    self.0.insert(ix, new_edit);
 287                    ix += 1;
 288
 289                    let old_edit = &mut self.0[ix];
 290                    old_edit.new.start = (old_edit.new.start as i32 + new_edit_delta) as u32;
 291                    old_edit.new.end = (old_edit.new.end as i32 + new_edit_delta) as u32;
 292                    new_delta += new_edit_delta;
 293                } else if new_edit.old.start <= self.0[ix].new.end {
 294                    let new_edit = new_edits.next().unwrap().clone();
 295                    let old_edit = &mut self.0[ix];
 296                    if new_edit.old.start < old_edit.new.start {
 297                        old_edit.old.start -= old_edit.new.start - new_edit.old.start;
 298                        old_edit.new.start = new_edit.new.start;
 299                    }
 300                    if new_edit.old.end > old_edit.new.end {
 301                        old_edit.old.end += new_edit.old.end - old_edit.new.end;
 302                        old_edit.new.end = new_edit.old.end;
 303                    }
 304
 305                    old_edit.new.end = (old_edit.new.end as i32 + new_edit_delta) as u32;
 306                    new_delta += new_edit_delta;
 307                    if old_edit.old.len() == 0 && old_edit.new.len() == 0 {
 308                        self.0.remove(ix);
 309                        continue 'outer;
 310                    }
 311                } else {
 312                    break;
 313                }
 314            }
 315
 316            ix += 1;
 317        }
 318
 319        self.0.extend(new_edits.cloned());
 320
 321        self
 322        // let mut other_ranges = edit.ranges.iter().peekable();
 323        // let mut new_ranges = Vec::new();
 324        // let insertion_len = edit.new_text.as_ref().map_or(0, |t| t.len());
 325        // let mut delta = 0;
 326
 327        // for mut self_range in self.ranges.iter().cloned() {
 328        //     self_range.start += delta;
 329        //     self_range.end += delta;
 330
 331        //     while let Some(other_range) = other_ranges.peek() {
 332        //         let mut other_range = (*other_range).clone();
 333        //         other_range.start += delta;
 334        //         other_range.end += delta;
 335
 336        //         if other_range.start <= self_range.end {
 337        //             other_ranges.next().unwrap();
 338        //             delta += insertion_len;
 339
 340        //             if other_range.end < self_range.start {
 341        //                 new_ranges.push(other_range.start..other_range.end + insertion_len);
 342        //                 self_range.start += insertion_len;
 343        //                 self_range.end += insertion_len;
 344        //             } else {
 345        //                 self_range.start = cmp::min(self_range.start, other_range.start);
 346        //                 self_range.end = cmp::max(self_range.end, other_range.end) + insertion_len;
 347        //             }
 348        //         } else {
 349        //             break;
 350        //         }
 351        //     }
 352
 353        //     new_ranges.push(self_range);
 354        // }
 355
 356        // for other_range in other_ranges {
 357        //     new_ranges.push(other_range.start + delta..other_range.end + delta + insertion_len);
 358        //     delta += insertion_len;
 359        // }
 360
 361        // self.ranges = new_ranges;
 362    }
 363
 364    fn compose2(&self, new: &Self) -> Patch {
 365        let mut composed = Vec::new();
 366        let mut new_edits = new.0.iter().cloned().peekable();
 367        let mut old_delta = 0;
 368        let mut new_delta = 0;
 369        for mut old_edit in self.0.iter().cloned() {
 370            let mut next_new_delta = new_delta;
 371            while let Some(mut new_edit) = new_edits.peek().cloned() {
 372                let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
 373                if new_edit.old.end < old_edit.new.start {
 374                    new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
 375                    new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
 376                    new_edits.next();
 377                    new_delta += new_edit_delta;
 378                    next_new_delta += new_edit_delta;
 379                    composed.push(new_edit);
 380                } else if new_edit.old.start <= old_edit.new.end {
 381                    if new_edit.old.start < old_edit.new.start {
 382                        old_edit.old.start -= old_edit.new.start - new_edit.old.start;
 383                        old_edit.new.start = new_edit.new.start;
 384                    }
 385                    if new_edit.old.end > old_edit.new.end {
 386                        old_edit.old.end += new_edit.old.end - old_edit.new.end;
 387                        old_edit.new.end = new_edit.old.end;
 388                    }
 389
 390                    old_edit.new.end = (old_edit.new.end as i32 + new_edit_delta) as u32;
 391                    new_edits.next();
 392                    next_new_delta += new_edit_delta;
 393                } else {
 394                    break;
 395                }
 396            }
 397
 398            old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
 399            old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
 400            old_delta += old_edit.new.len() as i32 - old_edit.old.len() as i32;
 401            new_delta = next_new_delta;
 402            composed.push(old_edit);
 403        }
 404        composed.extend(new_edits.map(|mut new_edit| {
 405            new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
 406            new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
 407            new_edit
 408        }));
 409
 410        Patch(composed)
 411    }
 412
 413    fn invert(&mut self) -> &mut Self {
 414        for edit in &mut self.0 {
 415            mem::swap(&mut edit.old, &mut edit.new);
 416        }
 417        self
 418    }
 419}
 420
 421impl Snapshot {
 422    fn new(tab_snapshot: TabSnapshot) -> Self {
 423        let mut transforms = SumTree::new();
 424        let extent = tab_snapshot.text_summary();
 425        if !extent.lines.is_zero() {
 426            transforms.push(Transform::isomorphic(extent), &());
 427        }
 428        Self {
 429            transforms,
 430            tab_snapshot,
 431            interpolated: true,
 432        }
 433    }
 434
 435    fn interpolate(&mut self, new_tab_snapshot: TabSnapshot, edits: &[TabEdit]) -> Patch {
 436        let mut new_transforms;
 437        if edits.is_empty() {
 438            new_transforms = self.transforms.clone();
 439        } else {
 440            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 441            let mut edits = edits.into_iter().peekable();
 442            new_transforms =
 443                old_cursor.slice(&edits.peek().unwrap().old_lines.start, Bias::Right, &());
 444
 445            while let Some(edit) = edits.next() {
 446                if edit.new_lines.start > TabPoint::from(new_transforms.summary().input.lines) {
 447                    let summary = new_tab_snapshot.text_summary_for_range(
 448                        TabPoint::from(new_transforms.summary().input.lines)..edit.new_lines.start,
 449                    );
 450                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 451                }
 452
 453                if !edit.new_lines.is_empty() {
 454                    new_transforms.push_or_extend(Transform::isomorphic(
 455                        new_tab_snapshot.text_summary_for_range(edit.new_lines.clone()),
 456                    ));
 457                }
 458
 459                old_cursor.seek_forward(&edit.old_lines.end, Bias::Right, &());
 460                if let Some(next_edit) = edits.peek() {
 461                    if next_edit.old_lines.start > old_cursor.end(&()) {
 462                        if old_cursor.end(&()) > edit.old_lines.end {
 463                            let summary = self
 464                                .tab_snapshot
 465                                .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 466                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 467                        }
 468                        old_cursor.next(&());
 469                        new_transforms.push_tree(
 470                            old_cursor.slice(&next_edit.old_lines.start, Bias::Right, &()),
 471                            &(),
 472                        );
 473                    }
 474                } else {
 475                    if old_cursor.end(&()) > edit.old_lines.end {
 476                        let summary = self
 477                            .tab_snapshot
 478                            .text_summary_for_range(edit.old_lines.end..old_cursor.end(&()));
 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 = true;
 490        self.check_invariants();
 491        todo!()
 492    }
 493
 494    async fn update(
 495        &mut self,
 496        new_tab_snapshot: TabSnapshot,
 497        edits: &[TabEdit],
 498        wrap_width: f32,
 499        line_wrapper: &mut LineWrapper,
 500    ) -> Patch {
 501        #[derive(Debug)]
 502        struct RowEdit {
 503            old_rows: Range<u32>,
 504            new_rows: Range<u32>,
 505        }
 506
 507        let mut edits = edits.into_iter().peekable();
 508        let mut row_edits = Vec::new();
 509        while let Some(edit) = edits.next() {
 510            let mut row_edit = RowEdit {
 511                old_rows: edit.old_lines.start.row()..edit.old_lines.end.row() + 1,
 512                new_rows: edit.new_lines.start.row()..edit.new_lines.end.row() + 1,
 513            };
 514
 515            while let Some(next_edit) = edits.peek() {
 516                if next_edit.old_lines.start.row() <= row_edit.old_rows.end {
 517                    row_edit.old_rows.end = next_edit.old_lines.end.row() + 1;
 518                    row_edit.new_rows.end = next_edit.new_lines.end.row() + 1;
 519                    edits.next();
 520                } else {
 521                    break;
 522                }
 523            }
 524
 525            row_edits.push(row_edit);
 526        }
 527
 528        let mut new_transforms;
 529        if row_edits.is_empty() {
 530            new_transforms = self.transforms.clone();
 531        } else {
 532            let mut row_edits = row_edits.into_iter().peekable();
 533            let mut old_cursor = self.transforms.cursor::<TabPoint>();
 534
 535            new_transforms = old_cursor.slice(
 536                &TabPoint::new(row_edits.peek().unwrap().old_rows.start, 0),
 537                Bias::Right,
 538                &(),
 539            );
 540
 541            while let Some(edit) = row_edits.next() {
 542                if edit.new_rows.start > new_transforms.summary().input.lines.row {
 543                    let summary = new_tab_snapshot.text_summary_for_range(
 544                        TabPoint::new(new_transforms.summary().input.lines.row, 0)
 545                            ..TabPoint::new(edit.new_rows.start, 0),
 546                    );
 547                    new_transforms.push_or_extend(Transform::isomorphic(summary));
 548                }
 549
 550                let mut line = String::new();
 551                let mut remaining = None;
 552                let mut chunks = new_tab_snapshot.chunks_at(TabPoint::new(edit.new_rows.start, 0));
 553                let mut edit_transforms = Vec::<Transform>::new();
 554                for _ in edit.new_rows.start..edit.new_rows.end {
 555                    while let Some(chunk) = remaining.take().or_else(|| chunks.next()) {
 556                        if let Some(ix) = chunk.find('\n') {
 557                            line.push_str(&chunk[..ix + 1]);
 558                            remaining = Some(&chunk[ix + 1..]);
 559                            break;
 560                        } else {
 561                            line.push_str(chunk)
 562                        }
 563                    }
 564
 565                    if line.is_empty() {
 566                        break;
 567                    }
 568
 569                    let mut prev_boundary_ix = 0;
 570                    for boundary in line_wrapper.wrap_line(&line, wrap_width) {
 571                        let wrapped = &line[prev_boundary_ix..boundary.ix];
 572                        push_isomorphic(&mut edit_transforms, TextSummary::from(wrapped));
 573                        edit_transforms.push(Transform::wrap(boundary.next_indent));
 574                        prev_boundary_ix = boundary.ix;
 575                    }
 576
 577                    if prev_boundary_ix < line.len() {
 578                        push_isomorphic(
 579                            &mut edit_transforms,
 580                            TextSummary::from(&line[prev_boundary_ix..]),
 581                        );
 582                    }
 583
 584                    line.clear();
 585                    yield_now().await;
 586                }
 587
 588                let mut edit_transforms = edit_transforms.into_iter();
 589                if let Some(transform) = edit_transforms.next() {
 590                    new_transforms.push_or_extend(transform);
 591                }
 592                new_transforms.extend(edit_transforms, &());
 593
 594                old_cursor.seek_forward(&TabPoint::new(edit.old_rows.end, 0), Bias::Right, &());
 595                if let Some(next_edit) = row_edits.peek() {
 596                    if next_edit.old_rows.start > old_cursor.end(&()).row() {
 597                        if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 598                            let summary = self.tab_snapshot.text_summary_for_range(
 599                                TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 600                            );
 601                            new_transforms.push_or_extend(Transform::isomorphic(summary));
 602                        }
 603                        old_cursor.next(&());
 604                        new_transforms.push_tree(
 605                            old_cursor.slice(
 606                                &TabPoint::new(next_edit.old_rows.start, 0),
 607                                Bias::Right,
 608                                &(),
 609                            ),
 610                            &(),
 611                        );
 612                    }
 613                } else {
 614                    if old_cursor.end(&()) > TabPoint::new(edit.old_rows.end, 0) {
 615                        let summary = self.tab_snapshot.text_summary_for_range(
 616                            TabPoint::new(edit.old_rows.end, 0)..old_cursor.end(&()),
 617                        );
 618                        new_transforms.push_or_extend(Transform::isomorphic(summary));
 619                    }
 620                    old_cursor.next(&());
 621                    new_transforms.push_tree(old_cursor.suffix(&()), &());
 622                }
 623            }
 624        }
 625
 626        self.transforms = new_transforms;
 627        self.tab_snapshot = new_tab_snapshot;
 628        self.interpolated = false;
 629        self.check_invariants();
 630        todo!()
 631    }
 632
 633    pub fn chunks_at(&self, wrap_row: u32) -> Chunks {
 634        let point = WrapPoint::new(wrap_row, 0);
 635        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 636        transforms.seek(&point, Bias::Right, &());
 637        let mut input_position = TabPoint(transforms.start().1 .0);
 638        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 639            input_position.0 += point.0 - transforms.start().0 .0;
 640        }
 641        let input_chunks = self.tab_snapshot.chunks_at(input_position);
 642        Chunks {
 643            input_chunks,
 644            transforms,
 645            output_position: point,
 646            input_chunk: "",
 647        }
 648    }
 649
 650    pub fn highlighted_chunks_for_rows(&mut self, rows: Range<u32>) -> HighlightedChunks {
 651        let output_start = WrapPoint::new(rows.start, 0);
 652        let output_end = WrapPoint::new(rows.end, 0);
 653        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 654        transforms.seek(&output_start, Bias::Right, &());
 655        let mut input_start = TabPoint(transforms.start().1 .0);
 656        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 657            input_start.0 += output_start.0 - transforms.start().0 .0;
 658        }
 659        let input_end = self
 660            .to_tab_point(output_end)
 661            .min(self.tab_snapshot.max_point());
 662        HighlightedChunks {
 663            input_chunks: self.tab_snapshot.highlighted_chunks(input_start..input_end),
 664            input_chunk: Default::default(),
 665            output_position: output_start,
 666            max_output_row: rows.end,
 667            transforms,
 668        }
 669    }
 670
 671    pub fn max_point(&self) -> WrapPoint {
 672        self.to_wrap_point(self.tab_snapshot.max_point())
 673    }
 674
 675    pub fn line_len(&self, row: u32) -> u32 {
 676        let mut len = 0;
 677        for chunk in self.chunks_at(row) {
 678            if let Some(newline_ix) = chunk.find('\n') {
 679                len += newline_ix;
 680                break;
 681            } else {
 682                len += chunk.len();
 683            }
 684        }
 685        len as u32
 686    }
 687
 688    pub fn soft_wrap_indent(&self, row: u32) -> Option<u32> {
 689        let mut cursor = self.transforms.cursor::<WrapPoint>();
 690        cursor.seek(&WrapPoint::new(row + 1, 0), Bias::Right, &());
 691        cursor.item().and_then(|transform| {
 692            if transform.is_isomorphic() {
 693                None
 694            } else {
 695                Some(transform.summary.output.lines.column)
 696            }
 697        })
 698    }
 699
 700    pub fn longest_row(&self) -> u32 {
 701        self.transforms.summary().output.longest_row
 702    }
 703
 704    pub fn buffer_rows(&self, start_row: u32) -> BufferRows {
 705        let mut transforms = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 706        transforms.seek(&WrapPoint::new(start_row, 0), Bias::Left, &());
 707        let mut input_row = transforms.start().1.row();
 708        if transforms.item().map_or(false, |t| t.is_isomorphic()) {
 709            input_row += start_row - transforms.start().0.row();
 710        }
 711        let soft_wrapped = transforms.item().map_or(false, |t| !t.is_isomorphic());
 712        let mut input_buffer_rows = self.tab_snapshot.buffer_rows(input_row);
 713        let input_buffer_row = input_buffer_rows.next().unwrap();
 714        BufferRows {
 715            transforms,
 716            input_buffer_row,
 717            input_buffer_rows,
 718            output_row: start_row,
 719            soft_wrapped,
 720            max_output_row: self.max_point().row(),
 721        }
 722    }
 723
 724    pub fn to_tab_point(&self, point: WrapPoint) -> TabPoint {
 725        let mut cursor = self.transforms.cursor::<(WrapPoint, TabPoint)>();
 726        cursor.seek(&point, Bias::Right, &());
 727        let mut tab_point = cursor.start().1 .0;
 728        if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 729            tab_point += point.0 - cursor.start().0 .0;
 730        }
 731        TabPoint(tab_point)
 732    }
 733
 734    pub fn to_wrap_point(&self, point: TabPoint) -> WrapPoint {
 735        let mut cursor = self.transforms.cursor::<(TabPoint, WrapPoint)>();
 736        cursor.seek(&point, Bias::Right, &());
 737        WrapPoint(cursor.start().1 .0 + (point.0 - cursor.start().0 .0))
 738    }
 739
 740    pub fn clip_point(&self, mut point: WrapPoint, bias: Bias) -> WrapPoint {
 741        if bias == Bias::Left {
 742            let mut cursor = self.transforms.cursor::<WrapPoint>();
 743            cursor.seek(&point, Bias::Right, &());
 744            if cursor.item().map_or(false, |t| !t.is_isomorphic()) {
 745                point = *cursor.start();
 746                *point.column_mut() -= 1;
 747            }
 748        }
 749
 750        self.to_wrap_point(self.tab_snapshot.clip_point(self.to_tab_point(point), bias))
 751    }
 752
 753    fn check_invariants(&self) {
 754        #[cfg(test)]
 755        {
 756            assert_eq!(
 757                TabPoint::from(self.transforms.summary().input.lines),
 758                self.tab_snapshot.max_point()
 759            );
 760
 761            {
 762                let mut transforms = self.transforms.cursor::<()>().peekable();
 763                while let Some(transform) = transforms.next() {
 764                    if let Some(next_transform) = transforms.peek() {
 765                        assert!(transform.is_isomorphic() != next_transform.is_isomorphic());
 766                    }
 767                }
 768            }
 769
 770            let mut expected_buffer_rows = Vec::new();
 771            let mut buffer_row = 0;
 772            let mut prev_tab_row = 0;
 773            for display_row in 0..=self.max_point().row() {
 774                let tab_point = self.to_tab_point(WrapPoint::new(display_row, 0));
 775                let soft_wrapped;
 776                if tab_point.row() == prev_tab_row {
 777                    soft_wrapped = display_row != 0;
 778                } else {
 779                    let fold_point = self.tab_snapshot.to_fold_point(tab_point, Bias::Left).0;
 780                    let buffer_point = fold_point.to_buffer_point(&self.tab_snapshot.fold_snapshot);
 781                    buffer_row = buffer_point.row;
 782                    prev_tab_row = tab_point.row();
 783                    soft_wrapped = false;
 784                }
 785                expected_buffer_rows.push((buffer_row, soft_wrapped));
 786            }
 787
 788            for start_display_row in 0..expected_buffer_rows.len() {
 789                assert_eq!(
 790                    self.buffer_rows(start_display_row as u32)
 791                        .collect::<Vec<_>>(),
 792                    &expected_buffer_rows[start_display_row..],
 793                    "invalid buffer_rows({}..)",
 794                    start_display_row
 795                );
 796            }
 797        }
 798    }
 799}
 800
 801impl<'a> Iterator for Chunks<'a> {
 802    type Item = &'a str;
 803
 804    fn next(&mut self) -> Option<Self::Item> {
 805        let transform = self.transforms.item()?;
 806        if let Some(display_text) = transform.display_text {
 807            if self.output_position > self.transforms.start().0 {
 808                self.output_position.0.column += transform.summary.output.lines.column;
 809                self.transforms.next(&());
 810                return Some(&display_text[1..]);
 811            } else {
 812                self.output_position.0 += transform.summary.output.lines;
 813                self.transforms.next(&());
 814                return Some(display_text);
 815            }
 816        }
 817
 818        if self.input_chunk.is_empty() {
 819            self.input_chunk = self.input_chunks.next().unwrap();
 820        }
 821
 822        let mut input_len = 0;
 823        let transform_end = self.transforms.end(&()).0;
 824        for c in self.input_chunk.chars() {
 825            let char_len = c.len_utf8();
 826            input_len += char_len;
 827            if c == '\n' {
 828                *self.output_position.row_mut() += 1;
 829                *self.output_position.column_mut() = 0;
 830            } else {
 831                *self.output_position.column_mut() += char_len as u32;
 832            }
 833
 834            if self.output_position >= transform_end {
 835                self.transforms.next(&());
 836                break;
 837            }
 838        }
 839
 840        let (prefix, suffix) = self.input_chunk.split_at(input_len);
 841        self.input_chunk = suffix;
 842        Some(prefix)
 843    }
 844}
 845
 846impl<'a> Iterator for HighlightedChunks<'a> {
 847    type Item = HighlightedChunk<'a>;
 848
 849    fn next(&mut self) -> Option<Self::Item> {
 850        if self.output_position.row() >= self.max_output_row {
 851            return None;
 852        }
 853
 854        let transform = self.transforms.item()?;
 855        if let Some(display_text) = transform.display_text {
 856            let mut start_ix = 0;
 857            let mut end_ix = display_text.len();
 858            let mut summary = transform.summary.output.lines;
 859
 860            if self.output_position > self.transforms.start().0 {
 861                // Exclude newline starting prior to the desired row.
 862                start_ix = 1;
 863                summary.row = 0;
 864            } else if self.output_position.row() + 1 >= self.max_output_row {
 865                // Exclude soft indentation ending after the desired row.
 866                end_ix = 1;
 867                summary.column = 0;
 868            }
 869
 870            self.output_position.0 += summary;
 871            self.transforms.next(&());
 872            return Some(HighlightedChunk {
 873                text: &display_text[start_ix..end_ix],
 874                ..self.input_chunk
 875            });
 876        }
 877
 878        if self.input_chunk.text.is_empty() {
 879            self.input_chunk = self.input_chunks.next().unwrap();
 880        }
 881
 882        let mut input_len = 0;
 883        let transform_end = self.transforms.end(&()).0;
 884        for c in self.input_chunk.text.chars() {
 885            let char_len = c.len_utf8();
 886            input_len += char_len;
 887            if c == '\n' {
 888                *self.output_position.row_mut() += 1;
 889                *self.output_position.column_mut() = 0;
 890            } else {
 891                *self.output_position.column_mut() += char_len as u32;
 892            }
 893
 894            if self.output_position >= transform_end {
 895                self.transforms.next(&());
 896                break;
 897            }
 898        }
 899
 900        let (prefix, suffix) = self.input_chunk.text.split_at(input_len);
 901        self.input_chunk.text = suffix;
 902        Some(HighlightedChunk {
 903            text: prefix,
 904            ..self.input_chunk
 905        })
 906    }
 907}
 908
 909impl<'a> Iterator for BufferRows<'a> {
 910    type Item = (u32, bool);
 911
 912    fn next(&mut self) -> Option<Self::Item> {
 913        if self.output_row > self.max_output_row {
 914            return None;
 915        }
 916
 917        let buffer_row = self.input_buffer_row;
 918        let soft_wrapped = self.soft_wrapped;
 919
 920        self.output_row += 1;
 921        self.transforms
 922            .seek_forward(&WrapPoint::new(self.output_row, 0), Bias::Left, &());
 923        if self.transforms.item().map_or(false, |t| t.is_isomorphic()) {
 924            self.input_buffer_row = self.input_buffer_rows.next().unwrap();
 925            self.soft_wrapped = false;
 926        } else {
 927            self.soft_wrapped = true;
 928        }
 929
 930        Some((buffer_row, soft_wrapped))
 931    }
 932}
 933
 934impl Transform {
 935    fn isomorphic(summary: TextSummary) -> Self {
 936        #[cfg(test)]
 937        assert!(!summary.lines.is_zero());
 938
 939        Self {
 940            summary: TransformSummary {
 941                input: summary.clone(),
 942                output: summary,
 943            },
 944            display_text: None,
 945        }
 946    }
 947
 948    fn wrap(indent: u32) -> Self {
 949        lazy_static! {
 950            static ref WRAP_TEXT: String = {
 951                let mut wrap_text = String::new();
 952                wrap_text.push('\n');
 953                wrap_text.extend((0..LineWrapper::MAX_INDENT as usize).map(|_| ' '));
 954                wrap_text
 955            };
 956        }
 957
 958        Self {
 959            summary: TransformSummary {
 960                input: TextSummary::default(),
 961                output: TextSummary {
 962                    lines: Point::new(1, indent),
 963                    first_line_chars: 0,
 964                    last_line_chars: indent,
 965                    longest_row: 1,
 966                    longest_row_chars: indent,
 967                },
 968            },
 969            display_text: Some(&WRAP_TEXT[..1 + indent as usize]),
 970        }
 971    }
 972
 973    fn is_isomorphic(&self) -> bool {
 974        self.display_text.is_none()
 975    }
 976}
 977
 978impl sum_tree::Item for Transform {
 979    type Summary = TransformSummary;
 980
 981    fn summary(&self) -> Self::Summary {
 982        self.summary.clone()
 983    }
 984}
 985
 986fn push_isomorphic(transforms: &mut Vec<Transform>, summary: TextSummary) {
 987    if let Some(last_transform) = transforms.last_mut() {
 988        if last_transform.is_isomorphic() {
 989            last_transform.summary.input += &summary;
 990            last_transform.summary.output += &summary;
 991            return;
 992        }
 993    }
 994    transforms.push(Transform::isomorphic(summary));
 995}
 996
 997trait SumTreeExt {
 998    fn push_or_extend(&mut self, transform: Transform);
 999}
1000
1001impl SumTreeExt for SumTree<Transform> {
1002    fn push_or_extend(&mut self, transform: Transform) {
1003        let mut transform = Some(transform);
1004        self.update_last(
1005            |last_transform| {
1006                if last_transform.is_isomorphic() && transform.as_ref().unwrap().is_isomorphic() {
1007                    let transform = transform.take().unwrap();
1008                    last_transform.summary.input += &transform.summary.input;
1009                    last_transform.summary.output += &transform.summary.output;
1010                }
1011            },
1012            &(),
1013        );
1014
1015        if let Some(transform) = transform {
1016            self.push(transform, &());
1017        }
1018    }
1019}
1020
1021impl WrapPoint {
1022    pub fn new(row: u32, column: u32) -> Self {
1023        Self(super::Point::new(row, column))
1024    }
1025
1026    #[cfg(test)]
1027    pub fn is_zero(&self) -> bool {
1028        self.0.is_zero()
1029    }
1030
1031    pub fn row(self) -> u32 {
1032        self.0.row
1033    }
1034
1035    pub fn column(self) -> u32 {
1036        self.0.column
1037    }
1038
1039    pub fn row_mut(&mut self) -> &mut u32 {
1040        &mut self.0.row
1041    }
1042
1043    pub fn column_mut(&mut self) -> &mut u32 {
1044        &mut self.0.column
1045    }
1046}
1047
1048impl sum_tree::Summary for TransformSummary {
1049    type Context = ();
1050
1051    fn add_summary(&mut self, other: &Self, _: &()) {
1052        self.input += &other.input;
1053        self.output += &other.output;
1054    }
1055}
1056
1057impl<'a> sum_tree::Dimension<'a, TransformSummary> for TabPoint {
1058    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1059        self.0 += summary.input.lines;
1060    }
1061}
1062
1063impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapPoint {
1064    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1065        self.0 += summary.output.lines;
1066    }
1067}
1068
1069fn compose(prev: &mut Vec<Edit>, next: &[Edit]) {}
1070
1071#[cfg(test)]
1072mod tests {
1073    use super::*;
1074    use crate::{
1075        display_map::{fold_map::FoldMap, tab_map::TabMap},
1076        test::Observer,
1077    };
1078    use language::{Buffer, RandomCharIter};
1079    use rand::prelude::*;
1080    use std::env;
1081
1082    #[gpui::test(iterations = 100)]
1083    async fn test_random_wraps(mut cx: gpui::TestAppContext, mut rng: StdRng) {
1084        cx.foreground().set_block_on_ticks(0..=50);
1085        cx.foreground().forbid_parking();
1086        let operations = env::var("OPERATIONS")
1087            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1088            .unwrap_or(10);
1089
1090        let font_cache = cx.font_cache().clone();
1091        let font_system = cx.platform().fonts();
1092        let mut wrap_width = if rng.gen_bool(0.1) {
1093            None
1094        } else {
1095            Some(rng.gen_range(0.0..=1000.0))
1096        };
1097        let tab_size = rng.gen_range(1..=4);
1098        let family_id = font_cache.load_family(&["Helvetica"]).unwrap();
1099        let font_id = font_cache
1100            .select_font(family_id, &Default::default())
1101            .unwrap();
1102        let font_size = 14.0;
1103
1104        log::info!("Tab size: {}", tab_size);
1105        log::info!("Wrap width: {:?}", wrap_width);
1106
1107        let buffer = cx.add_model(|cx| {
1108            let len = rng.gen_range(0..10);
1109            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1110            Buffer::new(0, text, cx)
1111        });
1112        let (mut fold_map, folds_snapshot) = cx.read(|cx| FoldMap::new(buffer.clone(), cx));
1113        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1114        log::info!(
1115            "Unwrapped text (no folds): {:?}",
1116            buffer.read_with(&cx, |buf, _| buf.text())
1117        );
1118        log::info!(
1119            "Unwrapped text (unexpanded tabs): {:?}",
1120            folds_snapshot.text()
1121        );
1122        log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1123
1124        let mut line_wrapper = LineWrapper::new(font_id, font_size, font_system);
1125        let unwrapped_text = tabs_snapshot.text();
1126        let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1127
1128        let wrap_map = cx.add_model(|cx| {
1129            WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx)
1130        });
1131        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
1132
1133        if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1134            notifications.recv().await.unwrap();
1135        }
1136
1137        let (snapshot, _) =
1138            wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1139        let actual_text = snapshot.text();
1140        assert_eq!(
1141            actual_text, expected_text,
1142            "unwrapped text is: {:?}",
1143            unwrapped_text
1144        );
1145        log::info!("Wrapped text: {:?}", actual_text);
1146
1147        for _i in 0..operations {
1148            match rng.gen_range(0..=100) {
1149                0..=19 => {
1150                    wrap_width = if rng.gen_bool(0.2) {
1151                        None
1152                    } else {
1153                        Some(rng.gen_range(0.0..=1000.0))
1154                    };
1155                    log::info!("Setting wrap width to {:?}", wrap_width);
1156                    wrap_map.update(&mut cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1157                }
1158                20..=39 => {
1159                    for (folds_snapshot, edits) in
1160                        cx.read(|cx| fold_map.randomly_mutate(&mut rng, cx))
1161                    {
1162                        let (tabs_snapshot, edits) = tab_map.sync(folds_snapshot, edits);
1163                        let (mut snapshot, _) =
1164                            wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, edits, cx));
1165                        snapshot.check_invariants();
1166                        snapshot.verify_chunks(&mut rng);
1167                    }
1168                }
1169                _ => {
1170                    buffer.update(&mut cx, |buffer, _| buffer.randomly_mutate(&mut rng));
1171                }
1172            }
1173
1174            log::info!(
1175                "Unwrapped text (no folds): {:?}",
1176                buffer.read_with(&cx, |buf, _| buf.text())
1177            );
1178            let (folds_snapshot, edits) = cx.read(|cx| fold_map.read(cx));
1179            log::info!(
1180                "Unwrapped text (unexpanded tabs): {:?}",
1181                folds_snapshot.text()
1182            );
1183            let (tabs_snapshot, edits) = tab_map.sync(folds_snapshot, edits);
1184            log::info!("Unwrapped text (expanded tabs): {:?}", tabs_snapshot.text());
1185
1186            let unwrapped_text = tabs_snapshot.text();
1187            let expected_text = wrap_text(&unwrapped_text, wrap_width, &mut line_wrapper);
1188            let (mut snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
1189                map.sync(tabs_snapshot.clone(), edits, cx)
1190            });
1191            snapshot.check_invariants();
1192            snapshot.verify_chunks(&mut rng);
1193
1194            if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
1195                log::info!("Waiting for wrapping to finish");
1196                while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1197                    notifications.recv().await.unwrap();
1198                }
1199            }
1200
1201            if !wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
1202                let (mut wrapped_snapshot, _) =
1203                    wrap_map.update(&mut cx, |map, cx| map.sync(tabs_snapshot, Vec::new(), cx));
1204                let actual_text = wrapped_snapshot.text();
1205                log::info!("Wrapping finished: {:?}", actual_text);
1206                wrapped_snapshot.check_invariants();
1207                wrapped_snapshot.verify_chunks(&mut rng);
1208                assert_eq!(
1209                    actual_text, expected_text,
1210                    "unwrapped text is: {:?}",
1211                    unwrapped_text
1212                );
1213            }
1214        }
1215    }
1216
1217    fn wrap_text(
1218        unwrapped_text: &str,
1219        wrap_width: Option<f32>,
1220        line_wrapper: &mut LineWrapper,
1221    ) -> String {
1222        if let Some(wrap_width) = wrap_width {
1223            let mut wrapped_text = String::new();
1224            for (row, line) in unwrapped_text.split('\n').enumerate() {
1225                if row > 0 {
1226                    wrapped_text.push('\n')
1227                }
1228
1229                let mut prev_ix = 0;
1230                for boundary in line_wrapper.wrap_line(line, wrap_width) {
1231                    wrapped_text.push_str(&line[prev_ix..boundary.ix]);
1232                    wrapped_text.push('\n');
1233                    wrapped_text.push_str(&" ".repeat(boundary.next_indent as usize));
1234                    prev_ix = boundary.ix;
1235                }
1236                wrapped_text.push_str(&line[prev_ix..]);
1237            }
1238            wrapped_text
1239        } else {
1240            unwrapped_text.to_string()
1241        }
1242    }
1243
1244    impl Snapshot {
1245        fn text(&self) -> String {
1246            self.chunks_at(0).collect()
1247        }
1248
1249        fn verify_chunks(&mut self, rng: &mut impl Rng) {
1250            for _ in 0..5 {
1251                let mut end_row = rng.gen_range(0..=self.max_point().row());
1252                let start_row = rng.gen_range(0..=end_row);
1253                end_row += 1;
1254
1255                let mut expected_text = self.chunks_at(start_row).collect::<String>();
1256                if expected_text.ends_with("\n") {
1257                    expected_text.push('\n');
1258                }
1259                let mut expected_text = expected_text
1260                    .lines()
1261                    .take((end_row - start_row) as usize)
1262                    .collect::<Vec<_>>()
1263                    .join("\n");
1264                if end_row <= self.max_point().row() {
1265                    expected_text.push('\n');
1266                }
1267
1268                let actual_text = self
1269                    .highlighted_chunks_for_rows(start_row..end_row)
1270                    .map(|c| c.text)
1271                    .collect::<String>();
1272                assert_eq!(
1273                    expected_text,
1274                    actual_text,
1275                    "chunks != highlighted_chunks for rows {:?}",
1276                    start_row..end_row
1277                );
1278            }
1279        }
1280    }
1281}