Struct Signal 

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

A clonable handle to a piece of reactive state. React’s useState value: reading is cheap, writing notifies every observer (see super::watch).

All clones share one backing entity, so passing a Signal around — or providing it as context — gives every holder the same live value.

Implementations

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

pub fn binding(&self) -> Binding<T>

The whole signal as a binding. Writes go through Signal::set_if_changed, so equal values skip the notify.

impl<T: 'static> Signal<T>

pub fn lens<U: Clone + PartialEq + 'static>( &self, get: impl Fn(&T) -> U + 'static, set: impl Fn(&mut T, U) + 'static, ) -> Binding<U>

Project a field: signal of a struct -> binding of one field (a lens). Writes that leave the field unchanged skip the notify.

impl<T: 'static> Signal<T>

pub fn new(cx: &mut App, value: T) -> Self

Create a new signal holding value.

pub fn entity(&self) -> &Entity<T>

The backing entity — pass to cx.observe(...) or super::watch.

pub fn read<'a>(&self, cx: &'a App) -> &'a T

Borrow the current value.

pub fn get(&self, cx: &App) -> T

where T: Clone,

Clone out the current value.

pub fn set(&self, cx: &mut App, value: T)

Replace the value and notify observers.

pub fn set_if_changed(&self, cx: &mut App, value: T)

where T: PartialEq,

Replace the value and notify observers, unless the new value equals the current one — then nothing happens (no notify).

pub fn update(&self, cx: &mut App, f: impl FnOnce(&mut T))

Mutate the value in place and notify observers.

Trait Implementations

impl<T> Clone for Signal<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.