Struct zng_app::update::OnUpdateHandle

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pub struct OnUpdateHandle(/* private fields */);

Expand description

Represents an on_pre_update or on_update handler.

Drop all clones of this handle to drop the binding, or call perm to drop the handle but keep the handler alive for the duration of the app.

Implementations§

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impl OnUpdateHandle

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pub fn dummy() -> Self

Create a handle to nothing, the handle always in the unsubscribed state.

Note that Option<OnUpdateHandle> takes up the same space as OnUpdateHandle and avoids an allocation.

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pub fn perm(self)

Drops the handle but does not unsubscribe.

The handler stays in memory for the duration of the app or until another handle calls unsubscribe

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pub fn is_permanent(&self) -> bool

If another handle has called perm.

If true the var binding will stay active until the app exits, unless unsubscribe is called.

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pub fn unsubscribe(self)

Drops the handle and forces the handler to drop.

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pub fn is_unsubscribed(&self) -> bool

If another handle has called unsubscribe.

The handler is already dropped or will be dropped in the next app update, this is irreversible.

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pub fn downgrade(&self) -> WeakOnUpdateHandle

Create a weak handle.

Trait Implementations§

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impl Clone for OnUpdateHandle

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fn clone(&self) -> OnUpdateHandle

Returns a copy of the value. Read more

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

Performs copy-assignment from source. Read more

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impl Debug for OnUpdateHandle

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

Formats the value using the given formatter. Read more

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impl Hash for OnUpdateHandle

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

Feeds this value into the given Hasher. Read more

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

Feeds a slice of this type into the given Hasher. Read more

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impl PartialEq for OnUpdateHandle

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

This method tests for self and other values to be equal, and is used by ==.

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

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

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impl Eq for OnUpdateHandle

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impl StructuralPartialEq for OnUpdateHandle

Auto Trait Implementations§

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impl UnwindSafe for OnUpdateHandle

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> AnyVarValue for T
where T: VarValue,

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fn as_any(&self) -> &(dyn Any + 'static)

Access to dyn Any methods.

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fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Access to mut dyn Any methods.

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fn clone_boxed(&self) -> Box<dyn AnyVarValue>

Clone the value.

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fn clone_boxed_var(&self) -> Box<dyn AnyVar>

Clone the value into a new boxed LocalVar<Self>.

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fn into_any(self: Box<T>) -> Box<dyn Any>

Access to Box<dyn Any> methods.

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more

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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts 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 more

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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts 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 more

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