Struct VirtualItems 

#[non_exhaustive]
pub struct VirtualItems {
    pub count: usize,
    pub mode: VirtualMode,
    pub anchor_policy: VirtualAnchorPolicy,
    pub row_key: Arc<dyn Fn(usize) -> String + Send + Sync>,
    pub build_row: Arc<dyn Fn(usize) -> El + Send + Sync>,
}

Virtualized list state attached to a Kind::VirtualList node: row count, row-height policy, and the closures that identify and realize rows. Built via Self::new / Self::new_dyn or, more commonly, the crate::virtual_list / crate::virtual_list_dyn builders. See VirtualMode for the scope and policy discussion.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

count: usize

Total number of rows in the list (realized or not).

mode: VirtualMode

Row-height policy — see VirtualMode.

anchor_policy: VirtualAnchorPolicy

How the next frame’s scroll anchor is chosen after each layout pass (dynamic mode only).

row_key: Arc<dyn Fn(usize) -> String + Send + Sync>

Stable identity for a row by global index. Keys measured heights and ScrollRequest::ToRowKey targets across reorders / insertions; defaults to the index itself in fixed mode.

build_row: Arc<dyn Fn(usize) -> El + Send + Sync>

Realize the row at a global index. Called only for rows whose rect intersects the viewport.

Implementations

impl VirtualItems

pub fn new<F>(count: usize, row_height: f32, build_row: F) -> Self

where F: Fn(usize) -> El + Send + Sync + 'static,

Fixed-height list: every row is row_height logical pixels. Row keys default to the stringified index. Panics if row_height <= 0.0. Prefer the crate::virtual_list builder.

pub fn new_dyn<K, F>( count: usize, estimated_row_height: f32, row_key: K, build_row: F, ) -> Self

where K: Fn(usize) -> String + Send + Sync + 'static, F: Fn(usize) -> El + Send + Sync + 'static,

Variable-height list: rows start at estimated_row_height logical pixels and are replaced by real measurements as they become visible. row_key must give each row a stable identity. Panics if estimated_row_height <= 0.0. Prefer the crate::virtual_list_dyn builder.

pub fn append_only(self) -> Self

Declare the append-only contract on a dynamic list — see VirtualMode::Dynamic::append_only. No-op (and harmless) on a fixed list, whose range math is already O(1).

pub fn anchor_policy(self, policy: VirtualAnchorPolicy) -> Self

Replace the default anchor policy (VirtualAnchorPolicy::ViewportFraction at 0.25).

Trait Implementations

impl Clone for VirtualItems

fn clone(&self) -> VirtualItems

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VirtualItems

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

Formats the value using the given formatter.