pub struct On<'w, 't, E, B = ()>{ /* private fields */ }Expand description
A system parameter used by an observer to process events. See Observer and Event for examples.
On contains the triggered Event data for a given run of an Observer. It also provides access to the
Trigger, which for things like EntityEvent with a PropagateEntityTrigger,
includes control over event propagation.
The generic B: Bundle is used to further specialize the events that this observer is interested in.
The entity involved does not have to have these components, but the observer will only be
triggered if the event matches the components in B.
This is used to to avoid providing a generic argument in your event, as is done for Add
and the other lifecycle events.
Providing multiple components in this bundle will cause this event to be triggered by any matching component in the bundle, rather than requiring all of them to be present.
Implementations§
Source§impl<'w, 't, E, B> On<'w, 't, E, B>
impl<'w, 't, E, B> On<'w, 't, E, B>
Sourcepub fn new(
event: &'w mut E,
observer: Entity,
trigger: &'w mut <E as Event>::Trigger<'t>,
trigger_context: &'w TriggerContext,
) -> On<'w, 't, E, B>
pub fn new( event: &'w mut E, observer: Entity, trigger: &'w mut <E as Event>::Trigger<'t>, trigger_context: &'w TriggerContext, ) -> On<'w, 't, E, B>
Creates a new instance of On for the given triggered event.
Sourcepub fn trigger(&self) -> &<E as Event>::Trigger<'t>
pub fn trigger(&self) -> &<E as Event>::Trigger<'t>
Returns the Trigger context for this event.
Sourcepub fn trigger_mut(&mut self) -> &mut <E as Event>::Trigger<'t>
pub fn trigger_mut(&mut self) -> &mut <E as Event>::Trigger<'t>
Returns the mutable Trigger context for this event.
Sourcepub fn observer(&self) -> Entity
pub fn observer(&self) -> Entity
Returns the Entity of the Observer of the triggered event.
This allows you to despawn the observer, ceasing observation.
§Examples
#[derive(EntityEvent)]
struct AssertEvent {
entity: Entity,
}
fn assert_observer(event: On<AssertEvent>) {
assert_eq!(event.observer(), event.entity);
}
let mut world = World::new();
let entity = world.spawn(Observer::new(assert_observer)).id();
world.trigger(AssertEvent { entity }); Sourcepub fn caller(&self) -> MaybeLocation
pub fn caller(&self) -> MaybeLocation
Returns the source code location that triggered this observer, if the track_location cargo feature is enabled.
Source§impl<'w, 't, E, B> On<'w, 't, E, B>where
E: EntityEvent,
B: Bundle,
impl<'w, 't, E, B> On<'w, 't, E, B>where
E: EntityEvent,
B: Bundle,
Sourcepub fn target(&self) -> Entity
👎Deprecated since 0.17.0: Call On::event() to access the event, then read the target entity from the event directly.
pub fn target(&self) -> Entity
A deprecated way to retrieve the entity that this EntityEvent targeted at.
Access the event via On::event, then read the entity that the event was targeting.
Prefer using the field name directly for clarity,
but if you are working in a generic context, you can use EntityEvent::event_target.
Source§impl<'w, 't, const AUTO_PROPAGATE: bool, E, B, T> On<'w, 't, E, B>where
E: EntityEvent<Trigger<'a> = PropagateEntityTrigger<AUTO_PROPAGATE, E, T>> + for<'a> Event,
B: Bundle,
T: Traversal<E>,
impl<'w, 't, const AUTO_PROPAGATE: bool, E, B, T> On<'w, 't, E, B>where
E: EntityEvent<Trigger<'a> = PropagateEntityTrigger<AUTO_PROPAGATE, E, T>> + for<'a> Event,
B: Bundle,
T: Traversal<E>,
Sourcepub fn original_event_target(&self) -> Entity
pub fn original_event_target(&self) -> Entity
Returns the original Entity that this EntityEvent targeted via EntityEvent::event_target when it was first triggered,
prior to any propagation logic.
Sourcepub fn propagate(&mut self, should_propagate: bool)
pub fn propagate(&mut self, should_propagate: bool)
Enables or disables event propagation, allowing the same event to trigger observers on a chain of different entities.
The path an EntityEvent will propagate along is specified by the Traversal component defined in PropagateEntityTrigger.
EntityEvent does not propagate by default. To enable propagation, you must:
- Enable propagation in
EntityEventusing#[entity_event(propagate)]. SeeEntityEventfor details. - Either call
propagate(true)in the first observer or in theEntityEventderive add#[entity_event(auto_propagate)].
You can prevent an event from propagating further using propagate(false). This will prevent the event from triggering on the next
Entity in the Traversal, but note that all remaining observers for the current entity will still run.
Sourcepub fn get_propagate(&self) -> bool
pub fn get_propagate(&self) -> bool
Returns the value of the flag that controls event propagation. See propagate for more information.
Trait Implementations§
Source§impl<E, B> SystemInput for On<'_, '_, E, B>
Used for ObserverSystems.
impl<E, B> SystemInput for On<'_, '_, E, B>
Used for ObserverSystems.
Source§type Param<'i> = On<'i, 'i, E, B>
type Param<'i> = On<'i, 'i, E, B>
FunctionSystems.Source§type Inner<'i> = On<'i, 'i, E, B>
type Inner<'i> = On<'i, 'i, E, B>
System::run.Source§fn wrap(
this: <On<'_, '_, E, B> as SystemInput>::Inner<'_>,
) -> <On<'_, '_, E, B> as SystemInput>::Param<'_>
fn wrap( this: <On<'_, '_, E, B> as SystemInput>::Inner<'_>, ) -> <On<'_, '_, E, B> as SystemInput>::Param<'_>
SystemInput::Inner into a SystemInput::Param.Auto Trait Implementations§
impl<'w, 't, E, B> Freeze for On<'w, 't, E, B>
impl<'w, 't, E, B> RefUnwindSafe for On<'w, 't, E, B>
impl<'w, 't, E, B> Send for On<'w, 't, E, B>
impl<'w, 't, E, B> Sync for On<'w, 't, E, B>
impl<'w, 't, E, B> Unpin for On<'w, 't, E, B>where
B: Unpin,
impl<'w, 't, E, B = ()> !UnwindSafe for On<'w, 't, E, B>
Blanket Implementations§
Source§impl<T, U> AsBindGroupShaderType<U> for T
impl<T, U> AsBindGroupShaderType<U> for T
Source§fn as_bind_group_shader_type(&self, _images: &RenderAssets<GpuImage>) -> U
fn as_bind_group_shader_type(&self, _images: &RenderAssets<GpuImage>) -> U
T ShaderType for self. When used in AsBindGroup
derives, it is safe to assume that all images in self exist.Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<T, C, D> Curve<T> for D
impl<T, C, D> Curve<T> for D
Source§fn sample_unchecked(&self, t: f32) -> T
fn sample_unchecked(&self, t: f32) -> T
t, extracting the associated value.
This is the unchecked version of sampling, which should only be used if the sample time t
is already known to lie within the curve’s domain. Read moreSource§fn sample(&self, t: f32) -> Option<T>
fn sample(&self, t: f32) -> Option<T>
t, returning None if the point is
outside of the curve’s domain.Source§fn sample_clamped(&self, t: f32) -> T
fn sample_clamped(&self, t: f32) -> T
t, clamping t to lie inside the
domain of the curve.Source§impl<C, T> CurveExt<T> for Cwhere
C: Curve<T>,
impl<C, T> CurveExt<T> for Cwhere
C: Curve<T>,
Source§fn sample_iter(
&self,
iter: impl IntoIterator<Item = f32>,
) -> impl Iterator<Item = Option<T>>
fn sample_iter( &self, iter: impl IntoIterator<Item = f32>, ) -> impl Iterator<Item = Option<T>>
n >= 0 points on this curve at the parameter values t_n,
returning None if the point is outside of the curve’s domain. Read moreSource§fn sample_iter_unchecked(
&self,
iter: impl IntoIterator<Item = f32>,
) -> impl Iterator<Item = T>
fn sample_iter_unchecked( &self, iter: impl IntoIterator<Item = f32>, ) -> impl Iterator<Item = T>
n >= 0 points on this curve at the parameter values t_n,
extracting the associated values. This is the unchecked version of sampling, which should
only be used if the sample times t_n are already known to lie within the curve’s domain. Read moreSource§fn sample_iter_clamped(
&self,
iter: impl IntoIterator<Item = f32>,
) -> impl Iterator<Item = T>
fn sample_iter_clamped( &self, iter: impl IntoIterator<Item = f32>, ) -> impl Iterator<Item = T>
n >= 0 points on this curve at the parameter values t_n,
clamping t_n to lie inside the domain of the curve. Read moreSource§fn map<S, F>(self, f: F) -> MapCurve<T, S, Self, F>where
F: Fn(T) -> S,
fn map<S, F>(self, f: F) -> MapCurve<T, S, Self, F>where
F: Fn(T) -> S,
f; i.e., if the
sample at time t for this curve is x, the value at time t on the new curve will be
f(x).Source§fn reparametrize<F>(self, domain: Interval, f: F) -> ReparamCurve<T, Self, F>
fn reparametrize<F>(self, domain: Interval, f: F) -> ReparamCurve<T, Self, F>
Curve whose parameter space is related to the parameter space of this curve
by f. For each time t, the sample from the new curve at time t is the sample from
this curve at time f(t). The given domain will be the domain of the new curve. The
function f is expected to take domain into self.domain(). Read moreSource§fn reparametrize_linear(
self,
domain: Interval,
) -> Result<LinearReparamCurve<T, Self>, LinearReparamError>
fn reparametrize_linear( self, domain: Interval, ) -> Result<LinearReparamCurve<T, Self>, LinearReparamError>
Source§fn reparametrize_by_curve<C>(self, other: C) -> CurveReparamCurve<T, Self, C>
fn reparametrize_by_curve<C>(self, other: C) -> CurveReparamCurve<T, Self, C>
Source§fn graph(self) -> GraphCurve<T, Self>
fn graph(self) -> GraphCurve<T, Self>
Source§fn zip<S, C>(
self,
other: C,
) -> Result<ZipCurve<T, S, Self, C>, InvalidIntervalError>where
C: Curve<S>,
fn zip<S, C>(
self,
other: C,
) -> Result<ZipCurve<T, S, Self, C>, InvalidIntervalError>where
C: Curve<S>,
Source§fn chain<C>(self, other: C) -> Result<ChainCurve<T, Self, C>, ChainError>where
C: Curve<T>,
fn chain<C>(self, other: C) -> Result<ChainCurve<T, Self, C>, ChainError>where
C: Curve<T>,
Source§fn reverse(self) -> Result<ReverseCurve<T, Self>, ReverseError>
fn reverse(self) -> Result<ReverseCurve<T, Self>, ReverseError>
Source§fn repeat(self, count: usize) -> Result<RepeatCurve<T, Self>, RepeatError>
fn repeat(self, count: usize) -> Result<RepeatCurve<T, Self>, RepeatError>
Source§fn forever(self) -> Result<ForeverCurve<T, Self>, RepeatError>
fn forever(self) -> Result<ForeverCurve<T, Self>, RepeatError>
Source§fn ping_pong(self) -> Result<PingPongCurve<T, Self>, PingPongError>
fn ping_pong(self) -> Result<PingPongCurve<T, Self>, PingPongError>
Source§fn chain_continue<C>(
self,
other: C,
) -> Result<ContinuationCurve<T, Self, C>, ChainError>where
T: VectorSpace,
C: Curve<T>,
fn chain_continue<C>(
self,
other: C,
) -> Result<ContinuationCurve<T, Self, C>, ChainError>where
T: VectorSpace,
C: Curve<T>,
Source§fn samples(
&self,
samples: usize,
) -> Result<impl Iterator<Item = T>, ResamplingError>
fn samples( &self, samples: usize, ) -> Result<impl Iterator<Item = T>, ResamplingError>
Source§impl<C, T> CurveResampleExt<T> for C
impl<C, T> CurveResampleExt<T> for C
Source§fn resample<I>(
&self,
segments: usize,
interpolation: I,
) -> Result<SampleCurve<T, I>, ResamplingError>
fn resample<I>( &self, segments: usize, interpolation: I, ) -> Result<SampleCurve<T, I>, ResamplingError>
Curve to produce a new one that is defined by interpolation over equally
spaced sample values, using the provided interpolation to interpolate between adjacent samples.
The curve is interpolated on segments segments between samples. For example, if segments is 1,
only the start and end points of the curve are used as samples; if segments is 2, a sample at
the midpoint is taken as well, and so on. Read moreSource§fn resample_auto(
&self,
segments: usize,
) -> Result<SampleAutoCurve<T>, ResamplingError>where
T: StableInterpolate,
fn resample_auto(
&self,
segments: usize,
) -> Result<SampleAutoCurve<T>, ResamplingError>where
T: StableInterpolate,
Curve to produce a new one that is defined by interpolation over equally
spaced sample values, using automatic interpolation to interpolate between adjacent samples.
The curve is interpolated on segments segments between samples. For example, if segments is 1,
only the start and end points of the curve are used as samples; if segments is 2, a sample at
the midpoint is taken as well, and so on. Read moreSource§fn resample_uneven<I>(
&self,
sample_times: impl IntoIterator<Item = f32>,
interpolation: I,
) -> Result<UnevenSampleCurve<T, I>, ResamplingError>
fn resample_uneven<I>( &self, sample_times: impl IntoIterator<Item = f32>, interpolation: I, ) -> Result<UnevenSampleCurve<T, I>, ResamplingError>
Source§fn resample_uneven_auto(
&self,
sample_times: impl IntoIterator<Item = f32>,
) -> Result<UnevenSampleAutoCurve<T>, ResamplingError>where
T: StableInterpolate,
fn resample_uneven_auto(
&self,
sample_times: impl IntoIterator<Item = f32>,
) -> Result<UnevenSampleAutoCurve<T>, ResamplingError>where
T: StableInterpolate,
Curve to produce a new one that is defined by automatic interpolation over
samples taken at the given set of times. The given sample_times are expected to contain at least
two valid times within the curve’s domain interval. Read moreSource§impl<T, C> CurveWithDerivative<T> for Cwhere
T: HasTangent,
C: SampleDerivative<T>,
impl<T, C> CurveWithDerivative<T> for Cwhere
T: HasTangent,
C: SampleDerivative<T>,
Source§fn with_derivative(self) -> SampleDerivativeWrapper<C>
fn with_derivative(self) -> SampleDerivativeWrapper<C>
Source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
Source§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>, which can then be
downcast into Box<dyn ConcreteType> where ConcreteType implements Trait.Source§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Rc<Trait> (where Trait: Downcast) to Rc<Any>, which can then be further
downcast into Rc<ConcreteType> where ConcreteType implements Trait.Source§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
&Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &Any’s vtable from &Trait’s.Source§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
&mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &mut Any’s vtable from &mut Trait’s.Source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
Source§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can
then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.Source§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be
further downcast into Rc<ConcreteType> where ConcreteType implements Trait.Source§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
&Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &Any’s vtable from &Trait’s.Source§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
&mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot
generate &mut Any’s vtable from &mut Trait’s.Source§impl<T> DowncastSend for T
impl<T> DowncastSend for T
Source§impl<T> DowncastSync for T
impl<T> DowncastSync for T
Source§impl<T, W> HasTypeWitness<W> for Twhere
W: MakeTypeWitness<Arg = T>,
T: ?Sized,
impl<T, W> HasTypeWitness<W> for Twhere
W: MakeTypeWitness<Arg = T>,
T: ?Sized,
Source§impl<T> Identity for Twhere
T: ?Sized,
impl<T> Identity for Twhere
T: ?Sized,
Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
Source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§impl<T> IntoResult<T> for T
impl<T> IntoResult<T> for T
Source§fn into_result(self) -> Result<T, RunSystemError>
fn into_result(self) -> Result<T, RunSystemError>
Source§impl<R> Rng for R
impl<R> Rng for R
Source§fn random<T>(&mut self) -> Twhere
StandardUniform: Distribution<T>,
fn random<T>(&mut self) -> Twhere
StandardUniform: Distribution<T>,
StandardUniform distribution. Read moreSource§fn random_iter<T>(self) -> Iter<StandardUniform, Self, T> ⓘ
fn random_iter<T>(self) -> Iter<StandardUniform, Self, T> ⓘ
Source§fn random_range<T, R>(&mut self, range: R) -> Twhere
T: SampleUniform,
R: SampleRange<T>,
fn random_range<T, R>(&mut self, range: R) -> Twhere
T: SampleUniform,
R: SampleRange<T>,
Source§fn random_bool(&mut self, p: f64) -> bool
fn random_bool(&mut self, p: f64) -> bool
p of being true. Read moreSource§fn random_ratio(&mut self, numerator: u32, denominator: u32) -> bool
fn random_ratio(&mut self, numerator: u32, denominator: u32) -> bool
numerator/denominator of being
true. Read moreSource§fn sample<T, D>(&mut self, distr: D) -> Twhere
D: Distribution<T>,
fn sample<T, D>(&mut self, distr: D) -> Twhere
D: Distribution<T>,
Source§fn sample_iter<T, D>(self, distr: D) -> Iter<D, Self, T> ⓘwhere
D: Distribution<T>,
Self: Sized,
fn sample_iter<T, D>(self, distr: D) -> Iter<D, Self, T> ⓘwhere
D: Distribution<T>,
Self: Sized,
Source§fn gen<T>(&mut self) -> Twhere
StandardUniform: Distribution<T>,
fn gen<T>(&mut self) -> Twhere
StandardUniform: Distribution<T>,
random to avoid conflict with the new gen keyword in Rust 2024.Rng::random.Source§fn gen_range<T, R>(&mut self, range: R) -> Twhere
T: SampleUniform,
R: SampleRange<T>,
fn gen_range<T, R>(&mut self, range: R) -> Twhere
T: SampleUniform,
R: SampleRange<T>,
random_rangeRng::random_range.Source§impl<T, C, D> SampleDerivative<T> for D
impl<T, C, D> SampleDerivative<T> for D
Source§fn sample_with_derivative_unchecked(&self, t: f32) -> WithDerivative<T>
fn sample_with_derivative_unchecked(&self, t: f32) -> WithDerivative<T>
t, extracting the associated value
in addition to its derivative. This is the unchecked version of sampling, which
should only be used if the sample time t is already known to lie within the
curve’s domain. Read moreSource§fn sample_with_derivative(&self, t: f32) -> Option<WithDerivative<T>>
fn sample_with_derivative(&self, t: f32) -> Option<WithDerivative<T>>
t, returning
None if the point is outside of the curve’s domain.Source§fn sample_with_derivative_clamped(&self, t: f32) -> WithDerivative<T>
fn sample_with_derivative_clamped(&self, t: f32) -> WithDerivative<T>
t, clamping t
to lie inside the domain of the curve.Source§impl<R> TryRngCore for R
impl<R> TryRngCore for R
Source§type Error = Infallible
type Error = Infallible
Source§fn try_next_u32(&mut self) -> Result<u32, <R as TryRngCore>::Error>
fn try_next_u32(&mut self) -> Result<u32, <R as TryRngCore>::Error>
u32.Source§fn try_next_u64(&mut self) -> Result<u64, <R as TryRngCore>::Error>
fn try_next_u64(&mut self) -> Result<u64, <R as TryRngCore>::Error>
u64.Source§fn try_fill_bytes(
&mut self,
dst: &mut [u8],
) -> Result<(), <R as TryRngCore>::Error>
fn try_fill_bytes( &mut self, dst: &mut [u8], ) -> Result<(), <R as TryRngCore>::Error>
dest entirely with random data.Source§fn unwrap_mut(&mut self) -> UnwrapMut<'_, Self>
fn unwrap_mut(&mut self) -> UnwrapMut<'_, Self>
UnwrapMut wrapper.Source§fn read_adapter(&mut self) -> RngReadAdapter<'_, Self>where
Self: Sized,
fn read_adapter(&mut self) -> RngReadAdapter<'_, Self>where
Self: Sized,
RngCore to a RngReadAdapter.