Struct ViewRef 

#[repr(C)]
pub struct ViewRef {
    pub reference: EventPair,
}

A ViewRef is a handle to a kernel object which identifies a unique View across the system. Two ViewRefs to the same View have the same KOID.

Clients use a ViewRef to identify a View, to validate a View, and to receive a View invalidation signal.

As part of View creation, the client creates a linked ViewRef/ViewRefControl pair and hands the pair to Scenic (ViewRefControl is described below). The client must remove the ViewRef’s signal capabilities; otherwise the View is not created.

The client may freely clone its ViewRef and share it, even before sending it to Scenic.

Example 1. Accessibility accepts a ViewRef from a client to group the semantic nodes, and semantic operations, associated with a client’s View. It must validate a client’s ViewRef with Scenic.

Example 2. We use ViewRefs to create a FocusChain, which identifies Views considered as “in-focus” down the View hierarchy. When a View is destroyed, Scenic signals to all FocusChain holders that the ViewRef is now invalid.

Fields

reference: EventPair

Trait Implementations

impl Debug for ViewRef

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

Formats the value using the given formatter.

impl<___E> Encode<ViewRef, ___E> for ViewRef

where ___E: InternalHandleEncoder + ?Sized + HandleEncoder,

const COPY_OPTIMIZATION: CopyOptimization<Self, ViewRef>

Whether the conversion from Self to W is equivalent to copying the raw bytes of Self.

fn encode( self, encoder_: &mut ___E, out_: &mut MaybeUninit<ViewRef>, _: (), ) -> Result<(), EncodeError>

Encodes this value into an encoder and output.

impl<___E> EncodeOption<Box<'static, ViewRef>, ___E> for ViewRef

where ___E: Encoder + ?Sized, ViewRef: Encode<ViewRef, ___E>,

fn encode_option( this: Option<Self>, encoder: &mut ___E, out: &mut MaybeUninit<Box<'static, ViewRef>>, _: (), ) -> Result<(), EncodeError>

Encodes this optional value into an encoder and output.

impl FromWire<ViewRef> for ViewRef

const COPY_OPTIMIZATION: CopyOptimization<ViewRef, Self>

Whether the conversion from W to Self is equivalent to copying the raw bytes of W.

fn from_wire(wire: ViewRef) -> Self

Converts the given owned value to this type.

impl PartialEq for ViewRef

fn eq(&self, other: &ViewRef) -> 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 StructuralPartialEq for ViewRef