Arkham | Threading

The sync flag

You can enable the sync flag in your cargo.toml file by changing the Arkham deceleration to:

arkham = { version = "*", features=["sync"] }

With the sync flag enabled Res and State will be thread safe. This makes it easy to pass the application state or resources to other threads for processing.

Render signals

When manipulating data from outside of components, especially in other threads, it is useful to be able to notify the app instance that it needs to render changes to the screen. a Renderer provides the ability to signal the app instance that it needs to render.

let mut app = App::new(root_view);
let renderer = app.get_renderer();
std::thread::spawn(move || loop {
    renderer.render()
    std::thread::sleep(
        std::time::Duration::from_secs(10)
    );
});
app.run();

Full threading example

use arkham::prelude::*;

#[derive(Default)]
pub struct AppState {
    pub counter: i32,
}

fn main() {
    let app_state = State::new(AppState::default());
    let mut app = App::new(root_view).bind_state(app_state.clone());
    let renderer = app.get_renderer();

    std::thread::spawn(move || loop {
        app_state.get_mut().counter += 1;
        renderer.render();
        std::thread::sleep(std::time::Duration::from_secs(1));
    });

    app.run().unwrap();
}

fn root_view(ctx: &mut ViewContext, state: State<AppState>) {
    ctx.insert(0, format!("Count is {}", state.get().counter));
}