Struct UiChildren 

pub struct UiChildren<'w, 's> { /* private fields */ }

System param that gives access to UI children utilities.

Implementations

impl<'w, 's> UiChildren<'w, 's>

pub fn iter_ui_children( &'s self, entity: Entity, ) -> impl Iterator<Item = Entity> + 's

Iterates the children of entity.

pub fn get_parent(&'s self, entity: Entity) -> Option<Entity>

Returns the UI parent of the provided entity.

pub fn is_changed(&'s self, entity: Entity) -> bool

Given an entity in the UI hierarchy, check if its set of children has changed, e.g if children has been added/removed or if the order has changed.

pub fn is_ui_node(&'s self, entity: Entity) -> bool

Returns true if the given entity is either a Node or a [GhostNode].

Trait Implementations

impl SystemParam for UiChildren<'_, '_>

type State = FetchState

Used to store data which persists across invocations of a system.

type Item<'w, 's> = UiChildren<'w, 's>

The item type returned when constructing this system param. The value of this associated type should be Self, instantiated with new lifetimes.

fn init_state(world: &mut World) -> <UiChildren<'_, '_> as SystemParam>::State

Creates a new instance of this param’s State.

fn init_access( state: &<UiChildren<'_, '_> as SystemParam>::State, system_meta: &mut SystemMeta, component_access_set: &mut FilteredAccessSet, world: &mut World, )

Registers any World access used by this SystemParam

fn apply( state: &mut <UiChildren<'_, '_> as SystemParam>::State, system_meta: &SystemMeta, world: &mut World, )

Applies any deferred mutations stored in this SystemParam’s state. This is used to apply Commands during ApplyDeferred.

fn queue( state: &mut <UiChildren<'_, '_> as SystemParam>::State, system_meta: &SystemMeta, world: DeferredWorld<'_>, )

Queues any deferred mutations to be applied at the next ApplyDeferred.

unsafe fn validate_param<'w, 's>( state: &'s mut <UiChildren<'_, '_> as SystemParam>::State, _system_meta: &SystemMeta, _world: UnsafeWorldCell<'w>, ) -> Result<(), SystemParamValidationError>

Validates that the param can be acquired by the get_param.

unsafe fn get_param<'w, 's>( state: &'s mut <UiChildren<'_, '_> as SystemParam>::State, system_meta: &SystemMeta, world: UnsafeWorldCell<'w>, change_tick: Tick, ) -> <UiChildren<'_, '_> as SystemParam>::Item<'w, 's>

Creates a parameter to be passed into a SystemParamFunction.

impl<'w, 's> ReadOnlySystemParam for UiChildren<'w, 's>

where Query<'w, 's, Option<&'static Children>, With<Node>>: ReadOnlySystemParam, Query<'w, 's, Entity, Changed<Children>>: ReadOnlySystemParam, Query<'w, 's, &'static ChildOf>: ReadOnlySystemParam,