Enum agui_core::unit::Key

pub enum Key {
    Unique(u64),
    Local(u64),
    Global(u64),
}

The key used for caching a widget.

This is used as a cache key for retaining a widget across rebuilds. The u64 within it must be unique within the scope indicated by the variant, or a panic! will occur.

In order for a widget to be persisted across rebuilds, it must be destroyed and recreated in a single frame, it cannot be delayed or the old state will be lost.

Variants

Unique(u64)

Tuple Fields

0: u64

A unique key.

This should generally be created “above” the widget that uses it as a key, because it’s created anew each time.

Local(u64)

Tuple Fields

0: u64

A local key.

This should be unique within a widget’s build() method. Any widget with the same key across rebuilds will be cached and re-parented, instead of rebuilt.

Global(u64)

Tuple Fields

0: u64

A global key.

This should be unique throughout the entire system.

Implementations

impl Key

pub const fn single() -> Self

A helper function to cache a single Local widget.

pub fn unique() -> Self

Creates a Unique key.

pub fn local<V>(value: V) -> Self where
    V: Hash, 

Create a Local key based on the value.

pub fn global<V>(value: V) -> Self where
    V: Hash, 

Create a Global key based on the value.

Trait Implementations

impl Clone for Key

fn clone(&self) -> Key

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Key

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

Formats the value using the given formatter.

impl Hash for Key

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, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<Key> for Key

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

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

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

This method tests for !=.

impl Copy for Key

impl Eq for Key

impl StructuralEq for Key

impl StructuralPartialEq for Key