switch_tester.rs

use wasm_bindgen::prelude::*;
use wasm_bindgen::JsCast;
use yew::prelude::*;
use yew::services::console::ConsoleService;
use yew::web_sys::KeyboardEvent;
mod constants;

struct Model {
    key: String,
    link: ComponentLink<Self>,
}

enum Msg {
    KeyPressed(KeyboardEvent),
}

impl Component for Model {
    type Message = Msg;
    type Properties = ();
    fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
        ConsoleService::log("create");
        Self {
            link,
            key: "".to_string(),
        }
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        match msg {
            Msg::KeyPressed(e) => self.key = KeyboardEvent::key(&e),
        }
        true
    }

    fn change(&mut self, _props: Self::Properties) -> ShouldRender {
        // Should only return "true" if new properties are different to
        // previously received properties.
        // This component has no properties so we will always return "false".
        false
    }

    fn view(&self) -> Html {
        html! {
            <div>
                <p>{ format!("{:?}", self.key) }</p>
            </div>
        }
    }

    fn rendered(&mut self, first_render: bool) {
        if first_render {
            let f = self.link.callback(|e| Msg::KeyPressed(e));
            let f = Box::new(move |e: KeyboardEvent| f.emit(e)) as Box<dyn FnMut(_)>;
            let callback = Closure::wrap(f);
            let window = yew::web_sys::window().expect("should get window");
            window.set_onkeydown(Some(callback.as_ref().unchecked_ref()));
            callback.forget();
        }
    }
}

#[wasm_bindgen(start)]
pub fn run_app() -> Result<(), JsValue> {
    App::<Model>::new().mount_to_body();
    Ok(())
}