Struct LayoutSpatialIndex 

pub struct LayoutSpatialIndex { /* private fields */ }

Axis-aligned 2-D quadtree that indexes laid-out view bounding boxes.

All four children of a node share the same depth but cover distinct quadrants. Leaf nodes store up to MAX_ITEMS_PER_NODE entries before splitting. The tree is rebuilt from scratch each layout pass via rebuild; incremental updates are not supported because layout already performs incremental caching and the tree is cheap to rebuild.

P1-63: Reduces hit-testing, focus-traversal, and visibility-culling from O(N) linear scans to O(log N) quadtree lookups.

Implementations

impl LayoutSpatialIndex

pub fn new() -> Self

Construct an empty index.

pub fn rebuild( &mut self, root_bounds: Rect, entries: impl IntoIterator<Item = LayoutSpatialEntry>, )

Rebuild the index from a flat list of (hash, rect) pairs produced after a layout pass. root_bounds should cover the entire layout space (typically the root view’s bounds).

Contract: all rects must be in the same coordinate space.

pub fn hit_test(&self, x: f32, y: f32) -> Vec<LayoutSpatialEntry>

Return all entries whose bounding rect contains (x, y), ordered front-to-back (no particular guarantee — callers should sort by z).

Returns an empty Vec if the index is empty. Uses Rect::contains(x, y) which is the canonical point-in-rect test.

pub fn query_region(&self, region: &Rect) -> Vec<LayoutSpatialEntry>

Return all entries whose bounding rect overlaps region.

Trait Implementations

impl Default for LayoutSpatialIndex

fn default() -> Self

Returns the “default value” for a type.