Struct DerivedState 

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

A value computed from other states, which tells its readers only when the result changes. Compose’s derivedStateOf.

A list that changes on every keystroke and a screen that only cares whether the list is empty is the case it is for: the screen observes the derived boolean, and the boolean is recomputed on every change but only runs the screen again when it flips.

It belongs to the UI thread. Remember it, so it is computed once per change rather than once per composition.

Implementations

impl<T: Clone + PartialEq + 'static> DerivedState<T>

pub fn get(&self) -> T

The value, recorded as read by the scope composing now.

Trait Implementations

impl<T> Clone for DerivedState<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> PartialEq for DerivedState<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T: Clone + PartialEq + 'static> State<T> for DerivedState<T>

fn value(&self) -> T

The value, recorded as read by the scope composing now.