Trait Component 

pub trait Component: 'static {
    type State: 'static;

    // Required methods
    fn init(&self) -> Self::State;
    fn build(&self, state: &mut Self::State) -> impl View<Self::State>;
}

A piece of UI with retained local state (Flutter’s StatefulWidget analog).

Seeds State once with Component::init and produces the subtree with Component::build over &mut State. The subtree is any impl View over the component’s own State; ComponentWidget erases it into an AnyView (idempotent, so an any(..) body is not boxed twice).

Required Associated Types

type State: 'static

The retained local state across rebuilds.

Required Methods

fn init(&self) -> Self::State

Create the initial local state. Runs once, when the ComponentWidget is first built, under the component’s Owner.

A root component has no enclosing widget, so the shell runs its init/build under the process-lifetime root Owner: its context is visible to the whole tree and its cleanups run at process exit.

fn build(&self, state: &mut Self::State) -> impl View<Self::State>

Produce the subtree from the current local state.

Re-run on every rebuild and diffed against the previous view. The opaque return type captures the &self and &mut State borrows, so a caller that hands it out of a closure erases it first with AnyView::new(root.build(state)).

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors