Struct StateHandle 

pub struct StateHandle<S: State> { /* private fields */ }

A way to reach a widget’s state from outside its build: from a handler, a listener, a timer. Cheap to clone.

Implementations

impl<S: State> StateHandle<S>

pub fn set_state(&self, change: impl FnOnce(&mut S))

Changes the state, and asks for a rebuild.

Does nothing once the widget has left the tree: a timer that outlives its widget finds nothing to change.

pub fn read<R>(&self, read: impl FnOnce(&S) -> R) -> R

Reads the state.

pub fn widget(&self) -> Rc<S::Widget>

The widget’s current configuration.

pub fn is_mounted(&self) -> bool

Whether the widget is still in the tree.

pub fn callback(&self, change: impl Fn(&mut S) + 'static) -> Callback

A handler that changes the state, for anything that takes a Callback.

pub fn handler<T: Clone + 'static>( &self, change: impl Fn(&mut S, T) + 'static, ) -> impl Fn(T) -> Callback + 'static

A handler for a widget that reports a value — a field’s text, a slider’s position, a switch’s new setting: TextField::new(..).on_input(cx.handler(|s, text: String| s.name = text)).

It answers the value with a Callback that makes the change when it is delivered, which is what every widget’s setter takes and what leaves no doubt about the message type — a closure that returns nothing could be a handler for any.

Trait Implementations

impl<S: State> Clone for StateHandle<S>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.