block_map.rs

   1use super::{
   2    wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot},
   3    Highlights,
   4};
   5use crate::{EditorStyle, GutterDimensions};
   6use collections::{Bound, HashMap, HashSet};
   7use gpui::{AnyElement, Pixels, WindowContext};
   8use language::{BufferSnapshot, Chunk, Patch, Point};
   9use multi_buffer::{Anchor, ExcerptId, ExcerptRange, MultiBufferRow, ToPoint as _};
  10use parking_lot::Mutex;
  11use std::{
  12    cell::RefCell,
  13    cmp::{self, Ordering},
  14    fmt::Debug,
  15    ops::{Deref, DerefMut, Range, RangeBounds},
  16    sync::{
  17        atomic::{AtomicUsize, Ordering::SeqCst},
  18        Arc,
  19    },
  20};
  21use sum_tree::{Bias, SumTree};
  22use text::Edit;
  23
  24const NEWLINES: &[u8] = &[b'\n'; u8::MAX as usize];
  25
  26/// Tracks custom blocks such as diagnostics that should be displayed within buffer.
  27///
  28/// See the [`display_map` module documentation](crate::display_map) for more information.
  29pub struct BlockMap {
  30    next_block_id: AtomicUsize,
  31    wrap_snapshot: RefCell<WrapSnapshot>,
  32    blocks: Vec<Arc<Block>>,
  33    transforms: RefCell<SumTree<Transform>>,
  34    show_excerpt_controls: bool,
  35    buffer_header_height: u8,
  36    excerpt_header_height: u8,
  37    excerpt_footer_height: u8,
  38}
  39
  40pub struct BlockMapWriter<'a>(&'a mut BlockMap);
  41
  42#[derive(Clone)]
  43pub struct BlockSnapshot {
  44    wrap_snapshot: WrapSnapshot,
  45    transforms: SumTree<Transform>,
  46}
  47
  48#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
  49pub struct BlockId(usize);
  50
  51#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  52pub struct BlockPoint(pub Point);
  53
  54#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  55pub struct BlockRow(pub(super) u32);
  56
  57#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  58struct WrapRow(u32);
  59
  60pub type RenderBlock = Box<dyn Send + Fn(&mut BlockContext) -> AnyElement>;
  61
  62pub struct Block {
  63    id: BlockId,
  64    position: Anchor,
  65    height: u8,
  66    style: BlockStyle,
  67    render: Mutex<RenderBlock>,
  68    disposition: BlockDisposition,
  69}
  70
  71pub struct BlockProperties<P> {
  72    pub position: P,
  73    pub height: u8,
  74    pub style: BlockStyle,
  75    pub render: Box<dyn Send + Fn(&mut BlockContext) -> AnyElement>,
  76    pub disposition: BlockDisposition,
  77}
  78
  79#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
  80pub enum BlockStyle {
  81    Fixed,
  82    Flex,
  83    Sticky,
  84}
  85
  86pub struct BlockContext<'a, 'b> {
  87    pub context: &'b mut WindowContext<'a>,
  88    pub anchor_x: Pixels,
  89    pub max_width: Pixels,
  90    pub gutter_dimensions: &'b GutterDimensions,
  91    pub em_width: Pixels,
  92    pub line_height: Pixels,
  93    pub block_id: usize,
  94    pub editor_style: &'b EditorStyle,
  95}
  96
  97/// Whether the block should be considered above or below the anchor line
  98#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  99pub enum BlockDisposition {
 100    Above,
 101    Below,
 102}
 103
 104#[derive(Clone, Debug)]
 105struct Transform {
 106    summary: TransformSummary,
 107    block: Option<TransformBlock>,
 108}
 109
 110pub(crate) enum BlockType {
 111    Custom(BlockId),
 112    Header,
 113    Footer,
 114}
 115
 116pub(crate) trait BlockLike {
 117    fn block_type(&self) -> BlockType;
 118    fn disposition(&self) -> BlockDisposition;
 119}
 120
 121#[allow(clippy::large_enum_variant)]
 122#[derive(Clone)]
 123pub enum TransformBlock {
 124    Custom(Arc<Block>),
 125    ExcerptHeader {
 126        id: ExcerptId,
 127        buffer: BufferSnapshot,
 128        range: ExcerptRange<text::Anchor>,
 129        height: u8,
 130        starts_new_buffer: bool,
 131        show_excerpt_controls: bool,
 132    },
 133    ExcerptFooter {
 134        id: ExcerptId,
 135        disposition: BlockDisposition,
 136        height: u8,
 137    },
 138}
 139
 140impl BlockLike for TransformBlock {
 141    fn block_type(&self) -> BlockType {
 142        match self {
 143            TransformBlock::Custom(block) => BlockType::Custom(block.id),
 144            TransformBlock::ExcerptHeader { .. } => BlockType::Header,
 145            TransformBlock::ExcerptFooter { .. } => BlockType::Footer,
 146        }
 147    }
 148
 149    fn disposition(&self) -> BlockDisposition {
 150        self.disposition()
 151    }
 152}
 153
 154impl TransformBlock {
 155    fn disposition(&self) -> BlockDisposition {
 156        match self {
 157            TransformBlock::Custom(block) => block.disposition,
 158            TransformBlock::ExcerptHeader { .. } => BlockDisposition::Above,
 159            TransformBlock::ExcerptFooter { disposition, .. } => *disposition,
 160        }
 161    }
 162
 163    pub fn height(&self) -> u8 {
 164        match self {
 165            TransformBlock::Custom(block) => block.height,
 166            TransformBlock::ExcerptHeader { height, .. } => *height,
 167            TransformBlock::ExcerptFooter { height, .. } => *height,
 168        }
 169    }
 170}
 171
 172impl Debug for TransformBlock {
 173    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 174        match self {
 175            Self::Custom(block) => f.debug_struct("Custom").field("block", block).finish(),
 176            Self::ExcerptHeader {
 177                buffer,
 178                starts_new_buffer,
 179                id,
 180                ..
 181            } => f
 182                .debug_struct("ExcerptHeader")
 183                .field("id", &id)
 184                .field("path", &buffer.file().map(|f| f.path()))
 185                .field("starts_new_buffer", &starts_new_buffer)
 186                .finish(),
 187            TransformBlock::ExcerptFooter {
 188                id, disposition, ..
 189            } => f
 190                .debug_struct("ExcerptFooter")
 191                .field("id", &id)
 192                .field("disposition", &disposition)
 193                .finish(),
 194        }
 195    }
 196}
 197
 198#[derive(Clone, Debug, Default)]
 199struct TransformSummary {
 200    input_rows: u32,
 201    output_rows: u32,
 202}
 203
 204pub struct BlockChunks<'a> {
 205    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 206    input_chunks: wrap_map::WrapChunks<'a>,
 207    input_chunk: Chunk<'a>,
 208    output_row: u32,
 209    max_output_row: u32,
 210}
 211
 212#[derive(Clone)]
 213pub struct BlockBufferRows<'a> {
 214    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 215    input_buffer_rows: wrap_map::WrapBufferRows<'a>,
 216    output_row: BlockRow,
 217    started: bool,
 218}
 219
 220impl BlockMap {
 221    pub fn new(
 222        wrap_snapshot: WrapSnapshot,
 223        show_excerpt_controls: bool,
 224        buffer_header_height: u8,
 225        excerpt_header_height: u8,
 226        excerpt_footer_height: u8,
 227    ) -> Self {
 228        let row_count = wrap_snapshot.max_point().row() + 1;
 229        let map = Self {
 230            next_block_id: AtomicUsize::new(0),
 231            blocks: Vec::new(),
 232            transforms: RefCell::new(SumTree::from_item(Transform::isomorphic(row_count), &())),
 233            wrap_snapshot: RefCell::new(wrap_snapshot.clone()),
 234            show_excerpt_controls,
 235            buffer_header_height,
 236            excerpt_header_height,
 237            excerpt_footer_height,
 238        };
 239        map.sync(
 240            &wrap_snapshot,
 241            Patch::new(vec![Edit {
 242                old: 0..row_count,
 243                new: 0..row_count,
 244            }]),
 245        );
 246        map
 247    }
 248
 249    pub fn read(&self, wrap_snapshot: WrapSnapshot, edits: Patch<u32>) -> BlockSnapshot {
 250        self.sync(&wrap_snapshot, edits);
 251        *self.wrap_snapshot.borrow_mut() = wrap_snapshot.clone();
 252        BlockSnapshot {
 253            wrap_snapshot,
 254            transforms: self.transforms.borrow().clone(),
 255        }
 256    }
 257
 258    pub fn write(&mut self, wrap_snapshot: WrapSnapshot, edits: Patch<u32>) -> BlockMapWriter {
 259        self.sync(&wrap_snapshot, edits);
 260        *self.wrap_snapshot.borrow_mut() = wrap_snapshot;
 261        BlockMapWriter(self)
 262    }
 263
 264    fn sync(&self, wrap_snapshot: &WrapSnapshot, mut edits: Patch<u32>) {
 265        let buffer = wrap_snapshot.buffer_snapshot();
 266
 267        // Handle changing the last excerpt if it is empty.
 268        if buffer.trailing_excerpt_update_count()
 269            != self
 270                .wrap_snapshot
 271                .borrow()
 272                .buffer_snapshot()
 273                .trailing_excerpt_update_count()
 274        {
 275            let max_point = wrap_snapshot.max_point();
 276            let edit_start = wrap_snapshot.prev_row_boundary(max_point);
 277            let edit_end = max_point.row() + 1;
 278            edits = edits.compose([WrapEdit {
 279                old: edit_start..edit_end,
 280                new: edit_start..edit_end,
 281            }]);
 282        }
 283
 284        let edits = edits.into_inner();
 285        if edits.is_empty() {
 286            return;
 287        }
 288
 289        let mut transforms = self.transforms.borrow_mut();
 290        let mut new_transforms = SumTree::new();
 291        let old_row_count = transforms.summary().input_rows;
 292        let new_row_count = wrap_snapshot.max_point().row() + 1;
 293        let mut cursor = transforms.cursor::<WrapRow>();
 294        let mut last_block_ix = 0;
 295        let mut blocks_in_edit = Vec::new();
 296        let mut edits = edits.into_iter().peekable();
 297
 298        while let Some(edit) = edits.next() {
 299            // Preserve any old transforms that precede this edit.
 300            let old_start = WrapRow(edit.old.start);
 301            let new_start = WrapRow(edit.new.start);
 302            new_transforms.append(cursor.slice(&old_start, Bias::Left, &()), &());
 303            if let Some(transform) = cursor.item() {
 304                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 305                    new_transforms.push(transform.clone(), &());
 306                    cursor.next(&());
 307                    while let Some(transform) = cursor.item() {
 308                        if transform
 309                            .block
 310                            .as_ref()
 311                            .map_or(false, |b| b.disposition().is_below())
 312                        {
 313                            new_transforms.push(transform.clone(), &());
 314                            cursor.next(&());
 315                        } else {
 316                            break;
 317                        }
 318                    }
 319                }
 320            }
 321
 322            // Preserve any portion of an old transform that precedes this edit.
 323            let extent_before_edit = old_start.0 - cursor.start().0;
 324            push_isomorphic(&mut new_transforms, extent_before_edit);
 325
 326            // Skip over any old transforms that intersect this edit.
 327            let mut old_end = WrapRow(edit.old.end);
 328            let mut new_end = WrapRow(edit.new.end);
 329            cursor.seek(&old_end, Bias::Left, &());
 330            cursor.next(&());
 331            if old_end == *cursor.start() {
 332                while let Some(transform) = cursor.item() {
 333                    if transform
 334                        .block
 335                        .as_ref()
 336                        .map_or(false, |b| b.disposition().is_below())
 337                    {
 338                        cursor.next(&());
 339                    } else {
 340                        break;
 341                    }
 342                }
 343            }
 344
 345            // Combine this edit with any subsequent edits that intersect the same transform.
 346            while let Some(next_edit) = edits.peek() {
 347                if next_edit.old.start <= cursor.start().0 {
 348                    old_end = WrapRow(next_edit.old.end);
 349                    new_end = WrapRow(next_edit.new.end);
 350                    cursor.seek(&old_end, Bias::Left, &());
 351                    cursor.next(&());
 352                    if old_end == *cursor.start() {
 353                        while let Some(transform) = cursor.item() {
 354                            if transform
 355                                .block
 356                                .as_ref()
 357                                .map_or(false, |b| b.disposition().is_below())
 358                            {
 359                                cursor.next(&());
 360                            } else {
 361                                break;
 362                            }
 363                        }
 364                    }
 365                    edits.next();
 366                } else {
 367                    break;
 368                }
 369            }
 370
 371            // Find the blocks within this edited region.
 372            let new_buffer_start =
 373                wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 374            let start_bound = Bound::Included(new_buffer_start);
 375            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 376                probe
 377                    .position
 378                    .to_point(buffer)
 379                    .cmp(&new_buffer_start)
 380                    .then(Ordering::Greater)
 381            }) {
 382                Ok(ix) | Err(ix) => last_block_ix + ix,
 383            };
 384
 385            let end_bound;
 386            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 387                end_bound = Bound::Unbounded;
 388                self.blocks.len()
 389            } else {
 390                let new_buffer_end =
 391                    wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 392                end_bound = Bound::Excluded(new_buffer_end);
 393                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 394                    probe
 395                        .position
 396                        .to_point(buffer)
 397                        .cmp(&new_buffer_end)
 398                        .then(Ordering::Greater)
 399                }) {
 400                    Ok(ix) | Err(ix) => start_block_ix + ix,
 401                }
 402            };
 403            last_block_ix = end_block_ix;
 404
 405            debug_assert!(blocks_in_edit.is_empty());
 406            blocks_in_edit.extend(
 407                self.blocks[start_block_ix..end_block_ix]
 408                    .iter()
 409                    .map(|block| {
 410                        let mut position = block.position.to_point(buffer);
 411                        match block.disposition {
 412                            BlockDisposition::Above => position.column = 0,
 413                            BlockDisposition::Below => {
 414                                position.column = buffer.line_len(MultiBufferRow(position.row))
 415                            }
 416                        }
 417                        let position = wrap_snapshot.make_wrap_point(position, Bias::Left);
 418                        (position.row(), TransformBlock::Custom(block.clone()))
 419                    }),
 420            );
 421
 422            if buffer.show_headers() {
 423                blocks_in_edit.extend(BlockMap::header_blocks(
 424                    self.show_excerpt_controls,
 425                    self.excerpt_footer_height,
 426                    self.buffer_header_height,
 427                    self.excerpt_header_height,
 428                    buffer,
 429                    (start_bound, end_bound),
 430                    wrap_snapshot,
 431                ));
 432            }
 433
 434            BlockMap::sort_blocks(&mut blocks_in_edit);
 435
 436            // For each of these blocks, insert a new isomorphic transform preceding the block,
 437            // and then insert the block itself.
 438            for (block_row, block) in blocks_in_edit.drain(..) {
 439                let insertion_row = match block.disposition() {
 440                    BlockDisposition::Above => block_row,
 441                    BlockDisposition::Below => block_row + 1,
 442                };
 443                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 444                push_isomorphic(&mut new_transforms, extent_before_block);
 445                new_transforms.push(Transform::block(block), &());
 446            }
 447
 448            old_end = WrapRow(old_end.0.min(old_row_count));
 449            new_end = WrapRow(new_end.0.min(new_row_count));
 450
 451            // Insert an isomorphic transform after the final block.
 452            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 453            push_isomorphic(&mut new_transforms, extent_after_last_block);
 454
 455            // Preserve any portion of the old transform after this edit.
 456            let extent_after_edit = cursor.start().0 - old_end.0;
 457            push_isomorphic(&mut new_transforms, extent_after_edit);
 458        }
 459
 460        new_transforms.append(cursor.suffix(&()), &());
 461        debug_assert_eq!(
 462            new_transforms.summary().input_rows,
 463            wrap_snapshot.max_point().row() + 1
 464        );
 465
 466        drop(cursor);
 467        *transforms = new_transforms;
 468    }
 469
 470    pub fn replace_renderers(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 471        for block in &mut self.blocks {
 472            if let Some(render) = renderers.remove(&block.id) {
 473                *block.render.lock() = render;
 474            }
 475        }
 476    }
 477
 478    pub fn show_excerpt_controls(&self) -> bool {
 479        self.show_excerpt_controls
 480    }
 481
 482    pub fn header_blocks<'a, 'b: 'a, 'c: 'a + 'b, R, T>(
 483        show_excerpt_controls: bool,
 484        excerpt_footer_height: u8,
 485        buffer_header_height: u8,
 486        excerpt_header_height: u8,
 487        buffer: &'b multi_buffer::MultiBufferSnapshot,
 488        range: R,
 489        wrap_snapshot: &'c WrapSnapshot,
 490    ) -> impl Iterator<Item = (u32, TransformBlock)> + 'b
 491    where
 492        R: RangeBounds<T>,
 493        T: multi_buffer::ToOffset,
 494    {
 495        buffer
 496            .excerpt_boundaries_in_range(range)
 497            .flat_map(move |excerpt_boundary| {
 498                let wrap_row = wrap_snapshot
 499                    .make_wrap_point(Point::new(excerpt_boundary.row.0, 0), Bias::Left)
 500                    .row();
 501
 502                [
 503                    show_excerpt_controls
 504                        .then(|| {
 505                            excerpt_boundary.prev.as_ref().map(|prev| {
 506                                (
 507                                    wrap_row,
 508                                    TransformBlock::ExcerptFooter {
 509                                        id: prev.id,
 510                                        height: excerpt_footer_height,
 511                                        disposition: if excerpt_boundary.next.is_some() {
 512                                            BlockDisposition::Above
 513                                        } else {
 514                                            BlockDisposition::Below
 515                                        },
 516                                    },
 517                                )
 518                            })
 519                        })
 520                        .flatten(),
 521                    excerpt_boundary.next.map(|next| {
 522                        let starts_new_buffer = excerpt_boundary
 523                            .prev
 524                            .map_or(true, |prev| prev.buffer_id != next.buffer_id);
 525
 526                        (
 527                            wrap_row,
 528                            TransformBlock::ExcerptHeader {
 529                                id: next.id,
 530                                buffer: next.buffer,
 531                                range: next.range,
 532                                height: if starts_new_buffer {
 533                                    buffer_header_height
 534                                } else {
 535                                    excerpt_header_height
 536                                },
 537                                starts_new_buffer,
 538                                show_excerpt_controls,
 539                            },
 540                        )
 541                    }),
 542                ]
 543            })
 544            .flatten()
 545    }
 546
 547    pub(crate) fn sort_blocks<B: BlockLike>(blocks: &mut Vec<(u32, B)>) {
 548        // Place excerpt headers and footers above custom blocks on the same row
 549        blocks.sort_unstable_by(|(row_a, block_a), (row_b, block_b)| {
 550            row_a.cmp(row_b).then_with(|| {
 551                block_a
 552                    .disposition()
 553                    .cmp(&block_b.disposition())
 554                    .then_with(|| match ((block_a.block_type()), (block_b.block_type())) {
 555                        (BlockType::Footer, BlockType::Footer) => Ordering::Equal,
 556                        (BlockType::Footer, _) => Ordering::Less,
 557                        (_, BlockType::Footer) => Ordering::Greater,
 558                        (BlockType::Header, BlockType::Header) => Ordering::Equal,
 559                        (BlockType::Header, _) => Ordering::Less,
 560                        (_, BlockType::Header) => Ordering::Greater,
 561                        (BlockType::Custom(a_id), BlockType::Custom(b_id)) => a_id.cmp(&b_id),
 562                    })
 563            })
 564        });
 565    }
 566}
 567
 568fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 569    if rows == 0 {
 570        return;
 571    }
 572
 573    let mut extent = Some(rows);
 574    tree.update_last(
 575        |last_transform| {
 576            if last_transform.is_isomorphic() {
 577                let extent = extent.take().unwrap();
 578                last_transform.summary.input_rows += extent;
 579                last_transform.summary.output_rows += extent;
 580            }
 581        },
 582        &(),
 583    );
 584    if let Some(extent) = extent {
 585        tree.push(Transform::isomorphic(extent), &());
 586    }
 587}
 588
 589impl BlockPoint {
 590    pub fn new(row: u32, column: u32) -> Self {
 591        Self(Point::new(row, column))
 592    }
 593}
 594
 595impl Deref for BlockPoint {
 596    type Target = Point;
 597
 598    fn deref(&self) -> &Self::Target {
 599        &self.0
 600    }
 601}
 602
 603impl std::ops::DerefMut for BlockPoint {
 604    fn deref_mut(&mut self) -> &mut Self::Target {
 605        &mut self.0
 606    }
 607}
 608
 609impl<'a> BlockMapWriter<'a> {
 610    pub fn insert(
 611        &mut self,
 612        blocks: impl IntoIterator<Item = BlockProperties<Anchor>>,
 613    ) -> Vec<BlockId> {
 614        let mut ids = Vec::new();
 615        let mut edits = Patch::default();
 616        let wrap_snapshot = &*self.0.wrap_snapshot.borrow();
 617        let buffer = wrap_snapshot.buffer_snapshot();
 618
 619        for block in blocks {
 620            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 621            ids.push(id);
 622
 623            let position = block.position;
 624            let point = position.to_point(buffer);
 625            let wrap_row = wrap_snapshot
 626                .make_wrap_point(Point::new(point.row, 0), Bias::Left)
 627                .row();
 628            let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 629            let end_row = wrap_snapshot
 630                .next_row_boundary(WrapPoint::new(wrap_row, 0))
 631                .unwrap_or(wrap_snapshot.max_point().row() + 1);
 632
 633            let block_ix = match self
 634                .0
 635                .blocks
 636                .binary_search_by(|probe| probe.position.cmp(&position, buffer))
 637            {
 638                Ok(ix) | Err(ix) => ix,
 639            };
 640            self.0.blocks.insert(
 641                block_ix,
 642                Arc::new(Block {
 643                    id,
 644                    position,
 645                    height: block.height,
 646                    render: Mutex::new(block.render),
 647                    disposition: block.disposition,
 648                    style: block.style,
 649                }),
 650            );
 651
 652            edits = edits.compose([Edit {
 653                old: start_row..end_row,
 654                new: start_row..end_row,
 655            }]);
 656        }
 657
 658        self.0.sync(wrap_snapshot, edits);
 659        ids
 660    }
 661
 662    pub fn replace(&mut self, mut heights_and_renderers: HashMap<BlockId, (u8, RenderBlock)>) {
 663        let wrap_snapshot = &*self.0.wrap_snapshot.borrow();
 664        let buffer = wrap_snapshot.buffer_snapshot();
 665        let mut edits = Patch::default();
 666        let mut last_block_buffer_row = None;
 667
 668        for block in &mut self.0.blocks {
 669            if let Some((new_height, render)) = heights_and_renderers.remove(&block.id) {
 670                if block.height != new_height {
 671                    let new_block = Block {
 672                        id: block.id,
 673                        position: block.position,
 674                        height: new_height,
 675                        style: block.style,
 676                        render: Mutex::new(render),
 677                        disposition: block.disposition,
 678                    };
 679                    *block = Arc::new(new_block);
 680
 681                    let buffer_row = block.position.to_point(buffer).row;
 682                    if last_block_buffer_row != Some(buffer_row) {
 683                        last_block_buffer_row = Some(buffer_row);
 684                        let wrap_row = wrap_snapshot
 685                            .make_wrap_point(Point::new(buffer_row, 0), Bias::Left)
 686                            .row();
 687                        let start_row =
 688                            wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 689                        let end_row = wrap_snapshot
 690                            .next_row_boundary(WrapPoint::new(wrap_row, 0))
 691                            .unwrap_or(wrap_snapshot.max_point().row() + 1);
 692                        edits.push(Edit {
 693                            old: start_row..end_row,
 694                            new: start_row..end_row,
 695                        })
 696                    }
 697                }
 698            }
 699        }
 700
 701        self.0.sync(wrap_snapshot, edits);
 702    }
 703
 704    pub fn remove(&mut self, block_ids: HashSet<BlockId>) {
 705        let wrap_snapshot = &*self.0.wrap_snapshot.borrow();
 706        let buffer = wrap_snapshot.buffer_snapshot();
 707        let mut edits = Patch::default();
 708        let mut last_block_buffer_row = None;
 709        self.0.blocks.retain(|block| {
 710            if block_ids.contains(&block.id) {
 711                let buffer_row = block.position.to_point(buffer).row;
 712                if last_block_buffer_row != Some(buffer_row) {
 713                    last_block_buffer_row = Some(buffer_row);
 714                    let wrap_row = wrap_snapshot
 715                        .make_wrap_point(Point::new(buffer_row, 0), Bias::Left)
 716                        .row();
 717                    let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 718                    let end_row = wrap_snapshot
 719                        .next_row_boundary(WrapPoint::new(wrap_row, 0))
 720                        .unwrap_or(wrap_snapshot.max_point().row() + 1);
 721                    edits.push(Edit {
 722                        old: start_row..end_row,
 723                        new: start_row..end_row,
 724                    })
 725                }
 726                false
 727            } else {
 728                true
 729            }
 730        });
 731        self.0.sync(wrap_snapshot, edits);
 732    }
 733}
 734
 735impl BlockSnapshot {
 736    #[cfg(test)]
 737    pub fn text(&self) -> String {
 738        self.chunks(
 739            0..self.transforms.summary().output_rows,
 740            false,
 741            Highlights::default(),
 742        )
 743        .map(|chunk| chunk.text)
 744        .collect()
 745    }
 746
 747    pub(crate) fn chunks<'a>(
 748        &'a self,
 749        rows: Range<u32>,
 750        language_aware: bool,
 751        highlights: Highlights<'a>,
 752    ) -> BlockChunks<'a> {
 753        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 754        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 755        let input_end = {
 756            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 757            let overshoot = if cursor
 758                .item()
 759                .map_or(false, |transform| transform.is_isomorphic())
 760            {
 761                rows.end - cursor.start().0 .0
 762            } else {
 763                0
 764            };
 765            cursor.start().1 .0 + overshoot
 766        };
 767        let input_start = {
 768            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 769            let overshoot = if cursor
 770                .item()
 771                .map_or(false, |transform| transform.is_isomorphic())
 772            {
 773                rows.start - cursor.start().0 .0
 774            } else {
 775                0
 776            };
 777            cursor.start().1 .0 + overshoot
 778        };
 779        BlockChunks {
 780            input_chunks: self.wrap_snapshot.chunks(
 781                input_start..input_end,
 782                language_aware,
 783                highlights,
 784            ),
 785            input_chunk: Default::default(),
 786            transforms: cursor,
 787            output_row: rows.start,
 788            max_output_row,
 789        }
 790    }
 791
 792    pub(super) fn buffer_rows(&self, start_row: BlockRow) -> BlockBufferRows {
 793        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 794        cursor.seek(&start_row, Bias::Right, &());
 795        let (output_start, input_start) = cursor.start();
 796        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 797            start_row.0 - output_start.0
 798        } else {
 799            0
 800        };
 801        let input_start_row = input_start.0 + overshoot;
 802        BlockBufferRows {
 803            transforms: cursor,
 804            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 805            output_row: start_row,
 806            started: false,
 807        }
 808    }
 809
 810    pub fn blocks_in_range(
 811        &self,
 812        rows: Range<u32>,
 813    ) -> impl Iterator<Item = (u32, &TransformBlock)> {
 814        let mut cursor = self.transforms.cursor::<BlockRow>();
 815        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 816        std::iter::from_fn(move || {
 817            while let Some(transform) = cursor.item() {
 818                let start_row = cursor.start().0;
 819                if start_row >= rows.end {
 820                    break;
 821                }
 822                if let Some(block) = &transform.block {
 823                    cursor.next(&());
 824                    return Some((start_row, block));
 825                } else {
 826                    cursor.next(&());
 827                }
 828            }
 829            None
 830        })
 831    }
 832
 833    pub fn max_point(&self) -> BlockPoint {
 834        let row = self.transforms.summary().output_rows - 1;
 835        BlockPoint::new(row, self.line_len(BlockRow(row)))
 836    }
 837
 838    pub fn longest_row(&self) -> u32 {
 839        let input_row = self.wrap_snapshot.longest_row();
 840        self.to_block_point(WrapPoint::new(input_row, 0)).row
 841    }
 842
 843    pub(super) fn line_len(&self, row: BlockRow) -> u32 {
 844        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 845        cursor.seek(&BlockRow(row.0), Bias::Right, &());
 846        if let Some(transform) = cursor.item() {
 847            let (output_start, input_start) = cursor.start();
 848            let overshoot = row.0 - output_start.0;
 849            if transform.block.is_some() {
 850                0
 851            } else {
 852                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 853            }
 854        } else {
 855            panic!("row out of range");
 856        }
 857    }
 858
 859    pub(super) fn is_block_line(&self, row: BlockRow) -> bool {
 860        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 861        cursor.seek(&row, Bias::Right, &());
 862        cursor.item().map_or(false, |t| t.block.is_some())
 863    }
 864
 865    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 866        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 867        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 868
 869        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 870        let mut search_left =
 871            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 872        let mut reversed = false;
 873
 874        loop {
 875            if let Some(transform) = cursor.item() {
 876                if transform.is_isomorphic() {
 877                    let (output_start_row, input_start_row) = cursor.start();
 878                    let (output_end_row, input_end_row) = cursor.end(&());
 879                    let output_start = Point::new(output_start_row.0, 0);
 880                    let input_start = Point::new(input_start_row.0, 0);
 881                    let input_end = Point::new(input_end_row.0, 0);
 882                    let input_point = if point.row >= output_end_row.0 {
 883                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 884                        self.wrap_snapshot
 885                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 886                    } else {
 887                        let output_overshoot = point.0.saturating_sub(output_start);
 888                        self.wrap_snapshot
 889                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 890                    };
 891
 892                    if (input_start..input_end).contains(&input_point.0) {
 893                        let input_overshoot = input_point.0.saturating_sub(input_start);
 894                        return BlockPoint(output_start + input_overshoot);
 895                    }
 896                }
 897
 898                if search_left {
 899                    cursor.prev(&());
 900                } else {
 901                    cursor.next(&());
 902                }
 903            } else if reversed {
 904                return self.max_point();
 905            } else {
 906                reversed = true;
 907                search_left = !search_left;
 908                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 909            }
 910        }
 911    }
 912
 913    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 914        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 915        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 916        if let Some(transform) = cursor.item() {
 917            debug_assert!(transform.is_isomorphic());
 918        } else {
 919            return self.max_point();
 920        }
 921
 922        let (input_start_row, output_start_row) = cursor.start();
 923        let input_start = Point::new(input_start_row.0, 0);
 924        let output_start = Point::new(output_start_row.0, 0);
 925        let input_overshoot = wrap_point.0 - input_start;
 926        BlockPoint(output_start + input_overshoot)
 927    }
 928
 929    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 930        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 931        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 932        if let Some(transform) = cursor.item() {
 933            match transform.block.as_ref().map(|b| b.disposition()) {
 934                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 935                Some(BlockDisposition::Below) => {
 936                    let wrap_row = cursor.start().1 .0 - 1;
 937                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 938                }
 939                None => {
 940                    let overshoot = block_point.row - cursor.start().0 .0;
 941                    let wrap_row = cursor.start().1 .0 + overshoot;
 942                    WrapPoint::new(wrap_row, block_point.column)
 943                }
 944            }
 945        } else {
 946            self.wrap_snapshot.max_point()
 947        }
 948    }
 949}
 950
 951impl Transform {
 952    fn isomorphic(rows: u32) -> Self {
 953        Self {
 954            summary: TransformSummary {
 955                input_rows: rows,
 956                output_rows: rows,
 957            },
 958            block: None,
 959        }
 960    }
 961
 962    fn block(block: TransformBlock) -> Self {
 963        Self {
 964            summary: TransformSummary {
 965                input_rows: 0,
 966                output_rows: block.height() as u32,
 967            },
 968            block: Some(block),
 969        }
 970    }
 971
 972    fn is_isomorphic(&self) -> bool {
 973        self.block.is_none()
 974    }
 975}
 976
 977impl<'a> Iterator for BlockChunks<'a> {
 978    type Item = Chunk<'a>;
 979
 980    fn next(&mut self) -> Option<Self::Item> {
 981        if self.output_row >= self.max_output_row {
 982            return None;
 983        }
 984
 985        let transform = self.transforms.item()?;
 986        if transform.block.is_some() {
 987            let block_start = self.transforms.start().0 .0;
 988            let mut block_end = self.transforms.end(&()).0 .0;
 989            self.transforms.next(&());
 990            if self.transforms.item().is_none() {
 991                block_end -= 1;
 992            }
 993
 994            let start_in_block = self.output_row - block_start;
 995            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 996            let line_count = end_in_block - start_in_block;
 997            self.output_row += line_count;
 998
 999            return Some(Chunk {
1000                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
1001                ..Default::default()
1002            });
1003        }
1004
1005        if self.input_chunk.text.is_empty() {
1006            if let Some(input_chunk) = self.input_chunks.next() {
1007                self.input_chunk = input_chunk;
1008            } else {
1009                self.output_row += 1;
1010                if self.output_row < self.max_output_row {
1011                    self.transforms.next(&());
1012                    return Some(Chunk {
1013                        text: "\n",
1014                        ..Default::default()
1015                    });
1016                } else {
1017                    return None;
1018                }
1019            }
1020        }
1021
1022        let transform_end = self.transforms.end(&()).0 .0;
1023        let (prefix_rows, prefix_bytes) =
1024            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
1025        self.output_row += prefix_rows;
1026        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
1027        self.input_chunk.text = suffix;
1028        if self.output_row == transform_end {
1029            self.transforms.next(&());
1030        }
1031
1032        Some(Chunk {
1033            text: prefix,
1034            ..self.input_chunk.clone()
1035        })
1036    }
1037}
1038
1039impl<'a> Iterator for BlockBufferRows<'a> {
1040    type Item = Option<BlockRow>;
1041
1042    fn next(&mut self) -> Option<Self::Item> {
1043        if self.started {
1044            self.output_row.0 += 1;
1045        } else {
1046            self.started = true;
1047        }
1048
1049        if self.output_row.0 >= self.transforms.end(&()).0 .0 {
1050            self.transforms.next(&());
1051        }
1052
1053        let transform = self.transforms.item()?;
1054        if transform.block.is_some() {
1055            Some(None)
1056        } else {
1057            Some(self.input_buffer_rows.next().unwrap().map(BlockRow))
1058        }
1059    }
1060}
1061
1062impl sum_tree::Item for Transform {
1063    type Summary = TransformSummary;
1064
1065    fn summary(&self) -> Self::Summary {
1066        self.summary.clone()
1067    }
1068}
1069
1070impl sum_tree::Summary for TransformSummary {
1071    type Context = ();
1072
1073    fn add_summary(&mut self, summary: &Self, _: &()) {
1074        self.input_rows += summary.input_rows;
1075        self.output_rows += summary.output_rows;
1076    }
1077}
1078
1079impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
1080    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1081        self.0 += summary.input_rows;
1082    }
1083}
1084
1085impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
1086    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1087        self.0 += summary.output_rows;
1088    }
1089}
1090
1091impl BlockDisposition {
1092    fn is_below(&self) -> bool {
1093        matches!(self, BlockDisposition::Below)
1094    }
1095}
1096
1097impl<'a> Deref for BlockContext<'a, '_> {
1098    type Target = WindowContext<'a>;
1099
1100    fn deref(&self) -> &Self::Target {
1101        self.context
1102    }
1103}
1104
1105impl DerefMut for BlockContext<'_, '_> {
1106    fn deref_mut(&mut self) -> &mut Self::Target {
1107        self.context
1108    }
1109}
1110
1111impl Block {
1112    pub fn render(&self, cx: &mut BlockContext) -> AnyElement {
1113        self.render.lock()(cx)
1114    }
1115
1116    pub fn position(&self) -> &Anchor {
1117        &self.position
1118    }
1119
1120    pub fn style(&self) -> BlockStyle {
1121        self.style
1122    }
1123}
1124
1125impl Debug for Block {
1126    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1127        f.debug_struct("Block")
1128            .field("id", &self.id)
1129            .field("position", &self.position)
1130            .field("disposition", &self.disposition)
1131            .finish()
1132    }
1133}
1134
1135// Count the number of bytes prior to a target point. If the string doesn't contain the target
1136// point, return its total extent. Otherwise return the target point itself.
1137fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
1138    let mut row = 0;
1139    let mut offset = 0;
1140    for (ix, line) in s.split('\n').enumerate() {
1141        if ix > 0 {
1142            row += 1;
1143            offset += 1;
1144        }
1145        if row >= target {
1146            break;
1147        }
1148        offset += line.len();
1149    }
1150    (row, offset)
1151}
1152
1153#[cfg(test)]
1154mod tests {
1155    use std::env;
1156
1157    use super::*;
1158    use crate::display_map::inlay_map::InlayMap;
1159    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
1160    use gpui::{div, font, px, Element};
1161    use multi_buffer::MultiBuffer;
1162    use rand::prelude::*;
1163    use settings::SettingsStore;
1164    use util::RandomCharIter;
1165
1166    #[gpui::test]
1167    fn test_offset_for_row() {
1168        assert_eq!(offset_for_row("", 0), (0, 0));
1169        assert_eq!(offset_for_row("", 1), (0, 0));
1170        assert_eq!(offset_for_row("abcd", 0), (0, 0));
1171        assert_eq!(offset_for_row("abcd", 1), (0, 4));
1172        assert_eq!(offset_for_row("\n", 0), (0, 0));
1173        assert_eq!(offset_for_row("\n", 1), (1, 1));
1174        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
1175        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
1176        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
1177        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
1178    }
1179
1180    #[gpui::test]
1181    fn test_basic_blocks(cx: &mut gpui::TestAppContext) {
1182        cx.update(|cx| init_test(cx));
1183
1184        let text = "aaa\nbbb\nccc\nddd";
1185
1186        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
1187        let buffer_snapshot = cx.update(|cx| buffer.read(cx).snapshot(cx));
1188        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1189        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1190        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1191        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 1.try_into().unwrap());
1192        let (wrap_map, wraps_snapshot) =
1193            cx.update(|cx| WrapMap::new(tab_snapshot, font("Helvetica"), px(14.0), None, cx));
1194        let mut block_map = BlockMap::new(wraps_snapshot.clone(), true, 1, 1, 1);
1195
1196        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1197        let block_ids = writer.insert(vec![
1198            BlockProperties {
1199                style: BlockStyle::Fixed,
1200                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
1201                height: 1,
1202                disposition: BlockDisposition::Above,
1203                render: Box::new(|_| div().into_any()),
1204            },
1205            BlockProperties {
1206                style: BlockStyle::Fixed,
1207                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
1208                height: 2,
1209                disposition: BlockDisposition::Above,
1210                render: Box::new(|_| div().into_any()),
1211            },
1212            BlockProperties {
1213                style: BlockStyle::Fixed,
1214                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
1215                height: 3,
1216                disposition: BlockDisposition::Below,
1217                render: Box::new(|_| div().into_any()),
1218            },
1219        ]);
1220
1221        let snapshot = block_map.read(wraps_snapshot, Default::default());
1222        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1223
1224        let blocks = snapshot
1225            .blocks_in_range(0..8)
1226            .map(|(start_row, block)| {
1227                let block = block.as_custom().unwrap();
1228                (start_row..start_row + block.height as u32, block.id)
1229            })
1230            .collect::<Vec<_>>();
1231
1232        // When multiple blocks are on the same line, the newer blocks appear first.
1233        assert_eq!(
1234            blocks,
1235            &[
1236                (1..2, block_ids[0]),
1237                (2..4, block_ids[1]),
1238                (7..10, block_ids[2]),
1239            ]
1240        );
1241
1242        assert_eq!(
1243            snapshot.to_block_point(WrapPoint::new(0, 3)),
1244            BlockPoint::new(0, 3)
1245        );
1246        assert_eq!(
1247            snapshot.to_block_point(WrapPoint::new(1, 0)),
1248            BlockPoint::new(4, 0)
1249        );
1250        assert_eq!(
1251            snapshot.to_block_point(WrapPoint::new(3, 3)),
1252            BlockPoint::new(6, 3)
1253        );
1254
1255        assert_eq!(
1256            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
1257            WrapPoint::new(0, 3)
1258        );
1259        assert_eq!(
1260            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
1261            WrapPoint::new(1, 0)
1262        );
1263        assert_eq!(
1264            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
1265            WrapPoint::new(1, 0)
1266        );
1267        assert_eq!(
1268            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
1269            WrapPoint::new(3, 3)
1270        );
1271
1272        assert_eq!(
1273            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
1274            BlockPoint::new(0, 3)
1275        );
1276        assert_eq!(
1277            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1278            BlockPoint::new(4, 0)
1279        );
1280        assert_eq!(
1281            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1282            BlockPoint::new(0, 3)
1283        );
1284        assert_eq!(
1285            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1286            BlockPoint::new(4, 0)
1287        );
1288        assert_eq!(
1289            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1290            BlockPoint::new(4, 0)
1291        );
1292        assert_eq!(
1293            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1294            BlockPoint::new(4, 0)
1295        );
1296        assert_eq!(
1297            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1298            BlockPoint::new(6, 3)
1299        );
1300        assert_eq!(
1301            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1302            BlockPoint::new(6, 3)
1303        );
1304        assert_eq!(
1305            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1306            BlockPoint::new(6, 3)
1307        );
1308        assert_eq!(
1309            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1310            BlockPoint::new(6, 3)
1311        );
1312
1313        assert_eq!(
1314            snapshot
1315                .buffer_rows(BlockRow(0))
1316                .map(|row| row.map(|r| r.0))
1317                .collect::<Vec<_>>(),
1318            &[
1319                Some(0),
1320                None,
1321                None,
1322                None,
1323                Some(1),
1324                Some(2),
1325                Some(3),
1326                None,
1327                None,
1328                None
1329            ]
1330        );
1331
1332        // Insert a line break, separating two block decorations into separate lines.
1333        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1334            buffer.edit([(Point::new(1, 1)..Point::new(1, 1), "!!!\n")], None, cx);
1335            buffer.snapshot(cx)
1336        });
1337
1338        let (inlay_snapshot, inlay_edits) =
1339            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1340        let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1341        let (tab_snapshot, tab_edits) =
1342            tab_map.sync(fold_snapshot, fold_edits, 4.try_into().unwrap());
1343        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1344            wrap_map.sync(tab_snapshot, tab_edits, cx)
1345        });
1346        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1347        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1348    }
1349
1350    #[gpui::test]
1351    fn test_replace_with_heights(cx: &mut gpui::TestAppContext) {
1352        let _update = cx.update(|cx| init_test(cx));
1353
1354        let text = "aaa\nbbb\nccc\nddd";
1355
1356        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
1357        let buffer_snapshot = cx.update(|cx| buffer.read(cx).snapshot(cx));
1358        let _subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1359        let (_inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1360        let (_fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1361        let (_tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 1.try_into().unwrap());
1362        let (_wrap_map, wraps_snapshot) =
1363            cx.update(|cx| WrapMap::new(tab_snapshot, font("Helvetica"), px(14.0), None, cx));
1364        let mut block_map = BlockMap::new(wraps_snapshot.clone(), false, 1, 1, 0);
1365
1366        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1367        let block_ids = writer.insert(vec![
1368            BlockProperties {
1369                style: BlockStyle::Fixed,
1370                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
1371                height: 1,
1372                disposition: BlockDisposition::Above,
1373                render: Box::new(|_| div().into_any()),
1374            },
1375            BlockProperties {
1376                style: BlockStyle::Fixed,
1377                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
1378                height: 2,
1379                disposition: BlockDisposition::Above,
1380                render: Box::new(|_| div().into_any()),
1381            },
1382            BlockProperties {
1383                style: BlockStyle::Fixed,
1384                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
1385                height: 3,
1386                disposition: BlockDisposition::Below,
1387                render: Box::new(|_| div().into_any()),
1388            },
1389        ]);
1390
1391        {
1392            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1393            assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1394
1395            let mut block_map_writer = block_map.write(wraps_snapshot.clone(), Default::default());
1396
1397            let mut hash_map = HashMap::default();
1398            let render: RenderBlock = Box::new(|_| div().into_any());
1399            hash_map.insert(block_ids[0], (2_u8, render));
1400            block_map_writer.replace(hash_map);
1401            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1402            assert_eq!(snapshot.text(), "aaa\n\n\n\n\nbbb\nccc\nddd\n\n\n");
1403        }
1404
1405        {
1406            let mut block_map_writer = block_map.write(wraps_snapshot.clone(), Default::default());
1407
1408            let mut hash_map = HashMap::default();
1409            let render: RenderBlock = Box::new(|_| div().into_any());
1410            hash_map.insert(block_ids[0], (1_u8, render));
1411            block_map_writer.replace(hash_map);
1412
1413            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1414            assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1415        }
1416
1417        {
1418            let mut block_map_writer = block_map.write(wraps_snapshot.clone(), Default::default());
1419
1420            let mut hash_map = HashMap::default();
1421            let render: RenderBlock = Box::new(|_| div().into_any());
1422            hash_map.insert(block_ids[0], (0_u8, render));
1423            block_map_writer.replace(hash_map);
1424
1425            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1426            assert_eq!(snapshot.text(), "aaa\n\n\nbbb\nccc\nddd\n\n\n");
1427        }
1428
1429        {
1430            let mut block_map_writer = block_map.write(wraps_snapshot.clone(), Default::default());
1431
1432            let mut hash_map = HashMap::default();
1433            let render: RenderBlock = Box::new(|_| div().into_any());
1434            hash_map.insert(block_ids[0], (3_u8, render));
1435            block_map_writer.replace(hash_map);
1436
1437            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1438            assert_eq!(snapshot.text(), "aaa\n\n\n\n\n\nbbb\nccc\nddd\n\n\n");
1439        }
1440
1441        {
1442            let mut block_map_writer = block_map.write(wraps_snapshot.clone(), Default::default());
1443
1444            let mut hash_map = HashMap::default();
1445            let render: RenderBlock = Box::new(|_| div().into_any());
1446            hash_map.insert(block_ids[0], (3_u8, render));
1447            block_map_writer.replace(hash_map);
1448
1449            let snapshot = block_map.read(wraps_snapshot.clone(), Default::default());
1450            // Same height as before, should remain the same
1451            assert_eq!(snapshot.text(), "aaa\n\n\n\n\n\nbbb\nccc\nddd\n\n\n");
1452        }
1453    }
1454
1455    #[gpui::test]
1456    fn test_blocks_on_wrapped_lines(cx: &mut gpui::TestAppContext) {
1457        cx.update(|cx| init_test(cx));
1458
1459        let _font_id = cx.text_system().font_id(&font("Helvetica")).unwrap();
1460
1461        let text = "one two three\nfour five six\nseven eight";
1462
1463        let buffer = cx.update(|cx| MultiBuffer::build_simple(text, cx));
1464        let buffer_snapshot = cx.update(|cx| buffer.read(cx).snapshot(cx));
1465        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1466        let (_, fold_snapshot) = FoldMap::new(inlay_snapshot);
1467        let (_, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1468        let (_, wraps_snapshot) = cx.update(|cx| {
1469            WrapMap::new(tab_snapshot, font("Helvetica"), px(14.0), Some(px(60.)), cx)
1470        });
1471        let mut block_map = BlockMap::new(wraps_snapshot.clone(), true, 1, 1, 0);
1472
1473        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1474        writer.insert(vec![
1475            BlockProperties {
1476                style: BlockStyle::Fixed,
1477                position: buffer_snapshot.anchor_after(Point::new(1, 12)),
1478                disposition: BlockDisposition::Above,
1479                render: Box::new(|_| div().into_any()),
1480                height: 1,
1481            },
1482            BlockProperties {
1483                style: BlockStyle::Fixed,
1484                position: buffer_snapshot.anchor_after(Point::new(1, 1)),
1485                disposition: BlockDisposition::Below,
1486                render: Box::new(|_| div().into_any()),
1487                height: 1,
1488            },
1489        ]);
1490
1491        // Blocks with an 'above' disposition go above their corresponding buffer line.
1492        // Blocks with a 'below' disposition go below their corresponding buffer line.
1493        let snapshot = block_map.read(wraps_snapshot, Default::default());
1494        assert_eq!(
1495            snapshot.text(),
1496            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1497        );
1498    }
1499
1500    #[gpui::test(iterations = 100)]
1501    fn test_random_blocks(cx: &mut gpui::TestAppContext, mut rng: StdRng) {
1502        cx.update(|cx| init_test(cx));
1503
1504        let operations = env::var("OPERATIONS")
1505            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1506            .unwrap_or(10);
1507
1508        let wrap_width = if rng.gen_bool(0.2) {
1509            None
1510        } else {
1511            Some(px(rng.gen_range(0.0..=100.0)))
1512        };
1513        let tab_size = 1.try_into().unwrap();
1514        let font_size = px(14.0);
1515        let buffer_start_header_height = rng.gen_range(1..=5);
1516        let excerpt_header_height = rng.gen_range(1..=5);
1517        let excerpt_footer_height = rng.gen_range(1..=5);
1518
1519        log::info!("Wrap width: {:?}", wrap_width);
1520        log::info!("Excerpt Header Height: {:?}", excerpt_header_height);
1521        log::info!("Excerpt Footer Height: {:?}", excerpt_footer_height);
1522
1523        let buffer = if rng.gen() {
1524            let len = rng.gen_range(0..10);
1525            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1526            log::info!("initial buffer text: {:?}", text);
1527            cx.update(|cx| MultiBuffer::build_simple(&text, cx))
1528        } else {
1529            cx.update(|cx| MultiBuffer::build_random(&mut rng, cx))
1530        };
1531
1532        let mut buffer_snapshot = cx.update(|cx| buffer.read(cx).snapshot(cx));
1533        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1534        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1535        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1536        let (wrap_map, wraps_snapshot) = cx
1537            .update(|cx| WrapMap::new(tab_snapshot, font("Helvetica"), font_size, wrap_width, cx));
1538        let mut block_map = BlockMap::new(
1539            wraps_snapshot,
1540            true,
1541            buffer_start_header_height,
1542            excerpt_header_height,
1543            excerpt_footer_height,
1544        );
1545        let mut custom_blocks = Vec::new();
1546
1547        for _ in 0..operations {
1548            let mut buffer_edits = Vec::new();
1549            match rng.gen_range(0..=100) {
1550                0..=19 => {
1551                    let wrap_width = if rng.gen_bool(0.2) {
1552                        None
1553                    } else {
1554                        Some(px(rng.gen_range(0.0..=100.0)))
1555                    };
1556                    log::info!("Setting wrap width to {:?}", wrap_width);
1557                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1558                }
1559                20..=39 => {
1560                    let block_count = rng.gen_range(1..=5);
1561                    let block_properties = (0..block_count)
1562                        .map(|_| {
1563                            let buffer = cx.update(|cx| buffer.read(cx).read(cx).clone());
1564                            let position = buffer.anchor_after(
1565                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1566                            );
1567
1568                            let disposition = if rng.gen() {
1569                                BlockDisposition::Above
1570                            } else {
1571                                BlockDisposition::Below
1572                            };
1573                            let height = rng.gen_range(1..5);
1574                            log::info!(
1575                                "inserting block {:?} {:?} with height {}",
1576                                disposition,
1577                                position.to_point(&buffer),
1578                                height
1579                            );
1580                            BlockProperties {
1581                                style: BlockStyle::Fixed,
1582                                position,
1583                                height,
1584                                disposition,
1585                                render: Box::new(|_| div().into_any()),
1586                            }
1587                        })
1588                        .collect::<Vec<_>>();
1589
1590                    let (inlay_snapshot, inlay_edits) =
1591                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1592                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1593                    let (tab_snapshot, tab_edits) =
1594                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1595                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1596                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1597                    });
1598                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1599                    let block_ids =
1600                        block_map.insert(block_properties.iter().map(|props| BlockProperties {
1601                            position: props.position,
1602                            height: props.height,
1603                            style: props.style,
1604                            render: Box::new(|_| div().into_any()),
1605                            disposition: props.disposition,
1606                        }));
1607                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1608                        custom_blocks.push((block_id, props));
1609                    }
1610                }
1611                40..=59 if !custom_blocks.is_empty() => {
1612                    let block_count = rng.gen_range(1..=4.min(custom_blocks.len()));
1613                    let block_ids_to_remove = (0..block_count)
1614                        .map(|_| {
1615                            custom_blocks
1616                                .remove(rng.gen_range(0..custom_blocks.len()))
1617                                .0
1618                        })
1619                        .collect();
1620
1621                    let (inlay_snapshot, inlay_edits) =
1622                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1623                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1624                    let (tab_snapshot, tab_edits) =
1625                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1626                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1627                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1628                    });
1629                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1630                    block_map.remove(block_ids_to_remove);
1631                }
1632                _ => {
1633                    buffer.update(cx, |buffer, cx| {
1634                        let mutation_count = rng.gen_range(1..=5);
1635                        let subscription = buffer.subscribe();
1636                        buffer.randomly_mutate(&mut rng, mutation_count, cx);
1637                        buffer_snapshot = buffer.snapshot(cx);
1638                        buffer_edits.extend(subscription.consume());
1639                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1640                    });
1641                }
1642            }
1643
1644            let (inlay_snapshot, inlay_edits) =
1645                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1646            let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1647            let (tab_snapshot, tab_edits) = tab_map.sync(fold_snapshot, fold_edits, tab_size);
1648            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1649                wrap_map.sync(tab_snapshot, tab_edits, cx)
1650            });
1651            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1652            assert_eq!(
1653                blocks_snapshot.transforms.summary().input_rows,
1654                wraps_snapshot.max_point().row() + 1
1655            );
1656            log::info!("blocks text: {:?}", blocks_snapshot.text());
1657
1658            let mut expected_blocks = Vec::new();
1659            expected_blocks.extend(custom_blocks.iter().map(|(id, block)| {
1660                let mut position = block.position.to_point(&buffer_snapshot);
1661                match block.disposition {
1662                    BlockDisposition::Above => {
1663                        position.column = 0;
1664                    }
1665                    BlockDisposition::Below => {
1666                        position.column = buffer_snapshot.line_len(MultiBufferRow(position.row));
1667                    }
1668                };
1669                let row = wraps_snapshot.make_wrap_point(position, Bias::Left).row();
1670                (
1671                    row,
1672                    ExpectedBlock::Custom {
1673                        disposition: block.disposition,
1674                        id: *id,
1675                        height: block.height,
1676                    },
1677                )
1678            }));
1679
1680            // Note that this needs to be synced with the related section in BlockMap::sync
1681            expected_blocks.extend(
1682                BlockMap::header_blocks(
1683                    true,
1684                    excerpt_footer_height,
1685                    buffer_start_header_height,
1686                    excerpt_header_height,
1687                    &buffer_snapshot,
1688                    0..,
1689                    &wraps_snapshot,
1690                )
1691                .map(|(row, block)| (row, block.into())),
1692            );
1693
1694            BlockMap::sort_blocks(&mut expected_blocks);
1695
1696            let mut sorted_blocks_iter = expected_blocks.into_iter().peekable();
1697
1698            let input_buffer_rows = buffer_snapshot
1699                .buffer_rows(MultiBufferRow(0))
1700                .collect::<Vec<_>>();
1701            let mut expected_buffer_rows = Vec::new();
1702            let mut expected_text = String::new();
1703            let mut expected_block_positions = Vec::new();
1704            let input_text = wraps_snapshot.text();
1705            for (row, input_line) in input_text.split('\n').enumerate() {
1706                let row = row as u32;
1707                if row > 0 {
1708                    expected_text.push('\n');
1709                }
1710
1711                let buffer_row = input_buffer_rows[wraps_snapshot
1712                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1713                    .row as usize];
1714
1715                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1716                    if *block_row == row && block.disposition() == BlockDisposition::Above {
1717                        let (_, block) = sorted_blocks_iter.next().unwrap();
1718                        let height = block.height() as usize;
1719                        expected_block_positions
1720                            .push((expected_text.matches('\n').count() as u32, block));
1721                        let text = "\n".repeat(height);
1722                        expected_text.push_str(&text);
1723                        for _ in 0..height {
1724                            expected_buffer_rows.push(None);
1725                        }
1726                    } else {
1727                        break;
1728                    }
1729                }
1730
1731                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1732                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1733                expected_text.push_str(input_line);
1734
1735                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1736                    if *block_row == row && block.disposition() == BlockDisposition::Below {
1737                        let (_, block) = sorted_blocks_iter.next().unwrap();
1738                        let height = block.height() as usize;
1739                        expected_block_positions
1740                            .push((expected_text.matches('\n').count() as u32 + 1, block));
1741                        let text = "\n".repeat(height);
1742                        expected_text.push_str(&text);
1743                        for _ in 0..height {
1744                            expected_buffer_rows.push(None);
1745                        }
1746                    } else {
1747                        break;
1748                    }
1749                }
1750            }
1751
1752            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1753            let expected_row_count = expected_lines.len();
1754            for start_row in 0..expected_row_count {
1755                let expected_text = expected_lines[start_row..].join("\n");
1756                let actual_text = blocks_snapshot
1757                    .chunks(
1758                        start_row as u32..blocks_snapshot.max_point().row + 1,
1759                        false,
1760                        Highlights::default(),
1761                    )
1762                    .map(|chunk| chunk.text)
1763                    .collect::<String>();
1764                assert_eq!(
1765                    actual_text, expected_text,
1766                    "incorrect text starting from row {}",
1767                    start_row
1768                );
1769                assert_eq!(
1770                    blocks_snapshot
1771                        .buffer_rows(BlockRow(start_row as u32))
1772                        .map(|row| row.map(|r| r.0))
1773                        .collect::<Vec<_>>(),
1774                    &expected_buffer_rows[start_row..]
1775                );
1776            }
1777
1778            assert_eq!(
1779                blocks_snapshot
1780                    .blocks_in_range(0..(expected_row_count as u32))
1781                    .map(|(row, block)| (row, block.clone().into()))
1782                    .collect::<Vec<_>>(),
1783                expected_block_positions
1784            );
1785
1786            let mut expected_longest_rows = Vec::new();
1787            let mut longest_line_len = -1_isize;
1788            for (row, line) in expected_lines.iter().enumerate() {
1789                let row = row as u32;
1790
1791                assert_eq!(
1792                    blocks_snapshot.line_len(BlockRow(row)),
1793                    line.len() as u32,
1794                    "invalid line len for row {}",
1795                    row
1796                );
1797
1798                let line_char_count = line.chars().count() as isize;
1799                match line_char_count.cmp(&longest_line_len) {
1800                    Ordering::Less => {}
1801                    Ordering::Equal => expected_longest_rows.push(row),
1802                    Ordering::Greater => {
1803                        longest_line_len = line_char_count;
1804                        expected_longest_rows.clear();
1805                        expected_longest_rows.push(row);
1806                    }
1807                }
1808            }
1809
1810            let longest_row = blocks_snapshot.longest_row();
1811            assert!(
1812                expected_longest_rows.contains(&longest_row),
1813                "incorrect longest row {}. expected {:?} with length {}",
1814                longest_row,
1815                expected_longest_rows,
1816                longest_line_len,
1817            );
1818
1819            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1820                let wrap_point = WrapPoint::new(row, 0);
1821                let block_point = blocks_snapshot.to_block_point(wrap_point);
1822                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1823            }
1824
1825            let mut block_point = BlockPoint::new(0, 0);
1826            for c in expected_text.chars() {
1827                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1828                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1829                assert_eq!(
1830                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1831                    left_point
1832                );
1833                assert_eq!(
1834                    left_buffer_point,
1835                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1836                    "{:?} is not valid in buffer coordinates",
1837                    left_point
1838                );
1839
1840                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1841                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1842                assert_eq!(
1843                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1844                    right_point
1845                );
1846                assert_eq!(
1847                    right_buffer_point,
1848                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1849                    "{:?} is not valid in buffer coordinates",
1850                    right_point
1851                );
1852
1853                if c == '\n' {
1854                    block_point.0 += Point::new(1, 0);
1855                } else {
1856                    block_point.column += c.len_utf8() as u32;
1857                }
1858            }
1859        }
1860
1861        #[derive(Debug, Eq, PartialEq)]
1862        enum ExpectedBlock {
1863            ExcerptHeader {
1864                height: u8,
1865                starts_new_buffer: bool,
1866            },
1867            ExcerptFooter {
1868                height: u8,
1869                disposition: BlockDisposition,
1870            },
1871            Custom {
1872                disposition: BlockDisposition,
1873                id: BlockId,
1874                height: u8,
1875            },
1876        }
1877
1878        impl BlockLike for ExpectedBlock {
1879            fn block_type(&self) -> BlockType {
1880                match self {
1881                    ExpectedBlock::Custom { id, .. } => BlockType::Custom(*id),
1882                    ExpectedBlock::ExcerptHeader { .. } => BlockType::Header,
1883                    ExpectedBlock::ExcerptFooter { .. } => BlockType::Footer,
1884                }
1885            }
1886
1887            fn disposition(&self) -> BlockDisposition {
1888                self.disposition()
1889            }
1890        }
1891
1892        impl ExpectedBlock {
1893            fn height(&self) -> u8 {
1894                match self {
1895                    ExpectedBlock::ExcerptHeader { height, .. } => *height,
1896                    ExpectedBlock::Custom { height, .. } => *height,
1897                    ExpectedBlock::ExcerptFooter { height, .. } => *height,
1898                }
1899            }
1900
1901            fn disposition(&self) -> BlockDisposition {
1902                match self {
1903                    ExpectedBlock::ExcerptHeader { .. } => BlockDisposition::Above,
1904                    ExpectedBlock::Custom { disposition, .. } => *disposition,
1905                    ExpectedBlock::ExcerptFooter { disposition, .. } => *disposition,
1906                }
1907            }
1908        }
1909
1910        impl From<TransformBlock> for ExpectedBlock {
1911            fn from(block: TransformBlock) -> Self {
1912                match block {
1913                    TransformBlock::Custom(block) => ExpectedBlock::Custom {
1914                        id: block.id,
1915                        disposition: block.disposition,
1916                        height: block.height,
1917                    },
1918                    TransformBlock::ExcerptHeader {
1919                        height,
1920                        starts_new_buffer,
1921                        ..
1922                    } => ExpectedBlock::ExcerptHeader {
1923                        height,
1924                        starts_new_buffer,
1925                    },
1926                    TransformBlock::ExcerptFooter {
1927                        height,
1928                        disposition,
1929                        ..
1930                    } => ExpectedBlock::ExcerptFooter {
1931                        height,
1932                        disposition,
1933                    },
1934                }
1935            }
1936        }
1937    }
1938
1939    fn init_test(cx: &mut gpui::AppContext) {
1940        let settings = SettingsStore::test(cx);
1941        cx.set_global(settings);
1942        theme::init(theme::LoadThemes::JustBase, cx);
1943    }
1944
1945    impl TransformBlock {
1946        fn as_custom(&self) -> Option<&Block> {
1947            match self {
1948                TransformBlock::Custom(block) => Some(block),
1949                TransformBlock::ExcerptHeader { .. } => None,
1950                TransformBlock::ExcerptFooter { .. } => None,
1951            }
1952        }
1953    }
1954
1955    impl BlockSnapshot {
1956        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1957            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1958        }
1959    }
1960}