Trait bevy::hierarchy::HierarchyQueryExt
pub trait HierarchyQueryExt<'w, 's, Q, F>where
Q: WorldQuery,
F: ReadOnlyWorldQuery,{
// Required methods
fn iter_descendants(&'w self, entity: Entity) -> DescendantIter<'w, 's, Q, F> ⓘ
where <Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Children>;
fn iter_ancestors(&'w self, entity: Entity) -> AncestorIter<'w, 's, Q, F> ⓘ
where <Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Parent>;
}Expand description
An extension trait for Query that adds hierarchy related methods.
Required Methods§
fn iter_descendants(&'w self, entity: Entity) -> DescendantIter<'w, 's, Q, F> ⓘwhere
<Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Children>,
fn iter_descendants(&'w self, entity: Entity) -> DescendantIter<'w, 's, Q, F> ⓘwhere <Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Children>,
Returns an Iterator of Entitys over all of entitys descendants.
Can only be called on a Query of Children (i.e. Query<&Children>).
Traverses the hierarchy breadth-first.
Examples
fn system(query: Query<Entity, With<Marker>>, children_query: Query<&Children>) {
let entity = query.single();
for descendant in children_query.iter_descendants(entity) {
// Do something!
}
}fn iter_ancestors(&'w self, entity: Entity) -> AncestorIter<'w, 's, Q, F> ⓘwhere
<Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Parent>,
fn iter_ancestors(&'w self, entity: Entity) -> AncestorIter<'w, 's, Q, F> ⓘwhere <Q as WorldQuery>::ReadOnly: WorldQuery<Item<'w> = &'w Parent>,
Returns an Iterator of Entitys over all of entitys ancestors.
Can only be called on a Query of Parent (i.e. Query<&Parent>).
Examples
fn system(query: Query<Entity, With<Marker>>, parent_query: Query<&Parent>) {
let entity = query.single();
for ancestor in parent_query.iter_ancestors(entity) {
// Do something!
}
}