Struct OverlayKey 

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

An overlay owner’s identity, allocated once by the owner and quoted back to it by every InputEvent::Overlay the root routes into its surface.

Stable for the owner’s lifetime: an owner allocates one key when it is built and stores it, re-registering under the same key every paint. The root therefore never has to recognise an owner by position, and an owner that floats two surfaces simply holds two keys.

Implementations

impl OverlayKey

pub fn next() -> Self

Allocate a fresh key, distinct from every other key handed out on this thread.

An owner calls this once, when it is built, and stores the result — calling it per frame would hand the root a new identity every paint and break the routing it exists to enable.

pub fn value(self) -> u64

The underlying integer, for a consumer that needs to key a map by it. Diagnostic and bookkeeping only — never derive routing from the value (allocation order is not a contract).

Trait Implementations

impl Clone for OverlayKey

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for OverlayKey

impl Debug for OverlayKey

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

Formats the value using the given formatter.

impl Eq for OverlayKey

impl Hash for OverlayKey

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for OverlayKey

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for OverlayKey

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for OverlayKey

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for OverlayKey