Struct slint_interpreter::Weak

pub struct Weak<T>where
    T: ComponentHandle,{ /* private fields */ }
Expand description

Struct that’s used to hold weak references of a Slint component

In order to create a Weak, you should use ComponentHandle::as_weak.

Strong references should not be captured by the functions given to a lambda, as this would produce a reference loop and leak the component. Instead, the callback function should capture a weak component.

The Weak component also implement Send and can be send to another thread. but the upgrade function will only return a valid component from the same thread as the one it has been created from. This is useful to use with invoke_from_event_loop() or Self::upgrade_in_event_loop().

Implementations§

§

impl<T> Weak<T>where T: ComponentHandle,

pub fn upgrade(&self) -> Option<T>where T: ComponentHandle,

Returns a new strongly referenced component if some other instance still holds a strong reference. Otherwise, returns None.

This also returns None if the current thread is not the thread that created the component

pub fn unwrap(&self) -> T

Convenience function that returns a new strongly referenced component if some other instance still holds a strong reference and the current thread is the thread that created this component. Otherwise, this function panics.

pub fn upgrade_in_event_loop( &self, func: impl FnOnce(T) + Send + 'static ) -> Result<(), EventLoopError>where T: 'static,

Convenience function that combines invoke_from_event_loop() with Self::upgrade()

The given functor will be added to an internal queue and will wake the event loop. On the next iteration of the event loop, the functor will be executed with a T as an argument.

If the component was dropped because there are no more strong reference to the component, the functor will not be called.

Example
slint::slint! { export component MyApp inherits Window { in property <int> foo; /* ... */ } }
let handle = MyApp::new().unwrap();
let handle_weak = handle.as_weak();
let thread = std::thread::spawn(move || {
    // ... Do some computation in the thread
    let foo = 42;
    // now forward the data to the main thread using upgrade_in_event_loop
    handle_weak.upgrade_in_event_loop(move |handle| handle.set_foo(foo));
});
handle.run().unwrap();

Trait Implementations§

§

impl<T> Clone for Weak<T>where T: ComponentHandle,

§

fn clone(&self) -> Weak<T>

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
§

impl<T> Send for Weak<T>where T: ComponentHandle,

Auto Trait Implementations§

§

impl<T> RefUnwindSafe for Weak<T>where <T as ComponentHandle>::Inner: RefUnwindSafe,

§

impl<T> !Sync for Weak<T>

§

impl<T> Unpin for Weak<T>

§

impl<T> UnwindSafe for Weak<T>where <T as ComponentHandle>::Inner: RefUnwindSafe,

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
§

impl<T> Downcast for Twhere T: Any,

§

fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>

Convert 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.
§

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
§

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

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
§

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

Convert &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> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

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

source§

fn into(self) -> U

Calls U::from(self).

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

§

impl<T> Pointable for T

§

const ALIGN: usize = mem::align_of::<T>()

The alignment of pointer.
§

type Init = T

The type for initializers.
§

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
§

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
§

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
source§

impl<T> ToOwned for Twhere T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.