Struct ElementRef 

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

A stable typed reference to a published native element.

Components normally store references as fields. A reference is unbound before its element is published and after removal, shutdown, or window close. Imperative methods only enqueue work; they do not expose or invoke the native WinUI object.

An accepted one-shot request completes exactly once. If its binding is retired before native processing, its completion receives the typed Unavailable error.

References are control-specific:

use windows_reactor::{Button, ElementRef, TextBox};

let button = ElementRef::<Button>::new();
let _ = TextBox::new().element_ref(&button);

use windows_reactor::ElementRef;

let _ = ElementRef::<u32>::new();

Implementations

impl<T: ReferenceControl> ElementRef<T>

pub fn new() -> Self

impl<T: FocusControl> ElementRef<T>

pub fn request_focus(&self) -> bool

Enqueues programmatic focus for the currently published element.

true means the request was accepted into the host queue. WinUI may later complete the request with false when focus does not move; that is not a host error.

pub fn request_focus_result( &self, completion: impl Fn(Result<bool, FocusError>) + 'static, ) -> bool

Enqueues programmatic focus and reports the native result asynchronously.

impl ElementRef<WebView2>

pub fn request_core_web_view2( &self, completion: impl Fn(Result<IUnknown, WebView2Error>) + 'static, ) -> bool

Requests creation of the CoreWebView2 object for the currently published control.

The returned COM object is the application-facing WebView2 core, not the XAML control owned by Reactor.

impl ElementRef<SwapChainPanel>

pub fn request_set_swap_chain( &self, swap_chain: IUnknown, completion: impl Fn(Result<(), SwapChainPanelError>) + 'static, ) -> bool

Attaches an application-owned DXGI swap chain to the published panel.

pub fn request_clear_swap_chain( &self, completion: impl Fn(Result<(), SwapChainPanelError>) + 'static, ) -> bool

Detaches the current DXGI swap chain from the published panel.

pub fn observe_surface( &self, callback: impl Fn(SwapChainPanelEvent) + 'static, ) -> ElementObservation

Observes panel metrics and frame rendering across published panel bindings.

Registration is accepted before publication. Each new binding creates a native subscription for that panel, and removal retires the old subscription.

impl ElementRef<Image>

pub fn request_set_native_source( &self, source: Option<IUnknown>, completion: impl Fn(Result<(), ImageSourceError>) + 'static, ) -> bool

Assigns an application-owned native ImageSource to the published image.

pub fn observe_rasterization_scale( &self, callback: impl Fn(f64) + 'static, ) -> ElementObservation

Observes rasterization scale across the image’s published bindings.

Registration is accepted before publication. Each new binding creates a native subscription after the image enters a live XAML tree.

impl ElementRef<Grid>

pub fn observe_composition_host( &self, callback: impl Fn(CompositionHostEvent) + 'static, ) -> ElementObservation

Observes an application-owned lifted Composition host across published bindings.

Registration is accepted before publication. Each new binding creates a native subscription for that host, and removal retires the old subscription.

pub fn request_set_child_visual( &self, visual: Option<IUnknown>, completion: impl Fn(Result<(), CompositionHostError>) + 'static, ) -> bool

Assigns an application-owned lifted Composition visual to the host element.

Trait Implementations

impl<T> Clone for ElementRef<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 ElementRef<T>

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

Formats the value using the given formatter.

impl<T: ReferenceControl> Default for ElementRef<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Eq for ElementRef<T>

impl<T> PartialEq for ElementRef<T>

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

Equality operator ==.

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

Inequality operator !=.