Struct VirtualRowMatrix 

pub struct VirtualRowMatrix {
    pub rows: Arc<[VirtualRow]>,
    pub line_index: Arc<[u32]>,
    pub source_line_count: u32,
    pub version: VirtualRowVersion,
}

The published virtual-row lane for one document.

Immutable once built; the publisher replaces the Arc<…> when providers mutate. Cheap to clone (Arc bump).

rows is sorted by (anchor_line, position) with Above < Below at the same line. line_index[i] is the index of the first row in rows whose anchor_line >= i; length is source_line_count + 1. The line index turns “how many virtual rows are anchored before line L” into a constant-time array lookup, which the crate::DisplaySliceIter uses to fast-forward past scrolled-off virtual rows in O(1) instead of O(V).

Fields

rows: Arc<[VirtualRow]>

line_index: Arc<[u32]>

source_line_count: u32

version: VirtualRowVersion

Implementations

impl VirtualRowMatrix

pub fn empty() -> Self

The empty matrix. The initial published value before any provider has emitted.

pub fn is_empty(&self) -> bool

true when no virtual rows are present. The crate::CellMatrix::display_slice fast path detects this to skip interleaver overhead entirely.

pub fn len(&self) -> usize

pub fn build( rows: Vec<VirtualRow>, source_line_count: u32, version: VirtualRowVersion, ) -> Self

Build a VirtualRowMatrix from an unsorted list. The rows are sorted by (anchor_line, position) and the line_index is computed.

source_line_count should match the document’s line count (so the line-index sentinel covers EOF). If a virtual row anchors past source_line_count, it is clamped to anchor at source_line_count (treated as “past EOF” by the interleaver, which emits it after the last document row).

pub fn first_row_at_or_after(&self, line: u32) -> u32

Index of the first row in rows whose anchor_line >= line. Returns rows.len() as u32 when every row anchors strictly below line.

O(1) array lookup when line <= source_line_count; returns rows.len() for queries past EOF.

pub fn virtual_rows_in_line_range(&self, lo: u32, hi: u32) -> u32

Number of virtual rows whose anchor sits in the inclusive document-line range [lo, hi], regardless of AnchorPosition. Returns 0 when lo > hi.

O(1) — two Self::first_row_at_or_after lookups. This is the geometry primitive the host’s scroll model uses to answer “how many display rows does the document-line span [lo, hi] occupy”, since each interleaved virtual row consumes a display row without being a document line. The count is position-agnostic on purpose: a bottom-anchored scroll over-reserves by at most the cursor line’s own Below rows, which is the safe direction (the last line is guaranteed clear of the modeline rather than flush against it).

VirtualRowKind::Sticky rows are excluded — they are rendered at the pane top outside the scroll window and do not displace content rows.

pub fn media_row_weights(&self, draws_media: bool) -> RowWeights

Iterator over all pinned rows in the matrix (see VirtualRowKind::is_pinned — Sticky headerlines + the BrandingBlock masthead). Used by renderers to paint the fixed top strip before the scrollable content window. IM.5: the RowWeights implied by this matrix’s media blocks.

A source line carrying a media block costs its own row plus the block’s DRAWN height, which is fractional and generally differs from the rows the block reserved. Everything else is absent from the map and therefore costs exactly what it always did.

draws_media is the renderer’s answer to “do I paint pixels”. The TUI passes false and gets a uniform map, so its scroll arithmetic is untouched — it renders the block’s alt-text cells in the reserved rows and those rows are one line tall, which is the truth for a terminal. Only one renderer runs in a process, so the two answers never collide.

pub fn sticky_rows(&self) -> impl Iterator<Item = &VirtualRow>

Trait Implementations

impl Clone for VirtualRowMatrix

fn clone(&self) -> VirtualRowMatrix

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for VirtualRowMatrix

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for VirtualRowMatrix

fn default() -> Self

Returns the “default value” for a type.