Trait FragmentQuery 

pub trait FragmentQuery {
    type FragmentId: Copy + Eq + Hash;

    // Required methods
    fn generation_id(&self) -> u64;
    fn hit_test(&self, point: Point) -> Option<FragmentHit<Self::FragmentId>>;
    fn box_model(&self, source_id: SourceNodeId) -> Option<BoxModel>;
    fn fragments_for_anchor<'a>(
        &'a self,
        anchor: &str,
    ) -> Box<dyn Iterator<Item = Self::FragmentId> + 'a>;
    fn text_range_for_fragment(
        &self,
        fragment: Self::FragmentId,
    ) -> Option<SourceRange>;
    fn rects_for_selection(&self, range: SourceRange) -> Vec<Rect>;
}

Common-minimum laid-out-geometry queries. Each lane that has a layout phase implements this. Internal FragmentId type is per- lane (opaque to consumers — only used as a map key).

Required Associated Types

type FragmentId: Copy + Eq + Hash

Per-lane opaque fragment identity. Consumers compare for equality and use as map keys.

Required Methods

fn generation_id(&self) -> u64

Epoch — invalidated on any relayout. Consumers cache against this; the value rolls when the plane regenerates.

fn hit_test(&self, point: Point) -> Option<FragmentHit<Self::FragmentId>>

Hit-test at a viewport point. Returns the topmost fragment hit (paint-order semantics), or None if the point falls outside any fragment.

fn box_model(&self, source_id: SourceNodeId) -> Option<BoxModel>

CSS box-model for a source node. None if the node has no fragment (e.g., display: none, or before layout completes).

fn fragments_for_anchor<'a>( &'a self, anchor: &str, ) -> Box<dyn Iterator<Item = Self::FragmentId> + 'a>

Fragments under a named anchor (e.g., #section-2).

fn text_range_for_fragment( &self, fragment: Self::FragmentId, ) -> Option<SourceRange>

Reverse mapping: fragment → source span. Used by selection, “what node was here,” and Apparatus.

fn rects_for_selection(&self, range: SourceRange) -> Vec<Rect>

Selection → screen rects. Multi-rect because a selection can span lines or wrap; consumers (selection-highlight painter) draw one rect per returned entry.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors