Struct WeakEntity 

pub struct WeakEntity<T> { /* private fields */ }

A weak reference to a entity of the given type.

Implementations

impl<T: 'static> WeakEntity<T>

pub fn upgrade(&self) -> Option<Entity<T>>

Upgrade this weak entity reference into a strong entity reference

pub fn update<C, R>( &self, cx: &mut C, update: impl FnOnce(&mut T, &mut Context<'_, T>) -> R, ) -> Result<R>

where C: AppContext, Result<C::Result<R>>: Flatten<R>,

Updates the entity referenced by this handle with the given function if the referenced entity still exists. Returns an error if the entity has been released.

pub fn update_in<C, R>( &self, cx: &mut C, update: impl FnOnce(&mut T, &mut Window, &mut Context<'_, T>) -> R, ) -> Result<R>

where C: VisualContext, Result<C::Result<R>>: Flatten<R>,

Updates the entity referenced by this handle with the given function if the referenced entity still exists, within a visual context that has a window. Returns an error if the entity has been released.

pub fn read_with<C, R>( &self, cx: &C, read: impl FnOnce(&T, &App) -> R, ) -> Result<R>

where C: AppContext, Result<C::Result<R>>: Flatten<R>,

Reads the entity referenced by this handle with the given function if the referenced entity still exists. Returns an error if the entity has been released.

pub fn new_invalid() -> Self

Create a new weak entity that can never be upgraded.

Methods from Deref<Target = AnyWeakEntity>

pub fn entity_id(&self) -> EntityId

Get the entity ID associated with this weak reference.

pub fn is_upgradable(&self) -> bool

Check if this weak handle can be upgraded, or if the entity has already been dropped

pub fn upgrade(&self) -> Option<AnyEntity>

Upgrade this weak entity reference to a strong reference.

Trait Implementations

impl<T> Clone for WeakEntity<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for WeakEntity<T>

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

Formats the value using the given formatter.

impl<T> Deref for WeakEntity<T>

type Target = AnyWeakEntity

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> DerefMut for WeakEntity<T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T> From<WeakEntity<T>> for AnyWeakEntity

fn from(entity: WeakEntity<T>) -> Self

Converts to this type from the input type.

impl<V: 'static + Render> From<WeakEntity<V>> for AnyWeakView

fn from(view: WeakEntity<V>) -> Self

Converts to this type from the input type.

impl<T> Hash for WeakEntity<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: 'static> Ord for WeakEntity<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T> PartialEq<Entity<T>> for WeakEntity<T>

fn eq(&self, other: &Entity<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialEq<WeakEntity<T>> for Entity<T>

fn eq(&self, other: &WeakEntity<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialEq for WeakEntity<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: 'static> PartialOrd for WeakEntity<T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Eq for WeakEntity<T>