Trait Application 

pub trait Application<M = Infallible> {
    // Required methods
    fn update(&mut self, signal: Signal<M>) -> UpdateResult;
    fn view(&self, frame: u64) -> ScopedElement<'_>;
}

A data-driven terminal application: what Runner::run drives.

AsyncApplication is the same seam for a host whose update awaits; the split exists because only the runtime differs, not the contract.

The runner mutably borrows the application only while delivering a Signal, then immutably borrows it to build the next frame. Because the returned tree is scoped to that immutable borrow, custom views can read application data directly without cloning it into an owned Element or sharing it through Rc<RefCell<_>>.

Rendering should be pure: persistent UI and domain state belongs on the application and changes only in update.

Required Methods

fn update(&mut self, signal: Signal<M>) -> UpdateResult

Update application state in response to a tick, terminal event, or message. Return UpdateResult::Clean only when the signal was unhandled, or UpdateResult::Consumed when it was handled without a repaint.

fn view(&self, frame: u64) -> ScopedElement<'_>

Build the ephemeral view tree for one numbered frame.

Dyn Compatibility

This trait is dyn compatible.

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

Implementors