How do I continue updating a window after running it with .run() ;)

[111nation]

Heyy, im very new to slint and still a noob at rust so please excuse any beginner mistakes!

I am trying to create a clock widget, and I am clueless on how to have an update loop after window.run(). Any synchronous or asynchronous solution is appreciated :)))

I only see updating in the .slint as a possible solution

#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]

use slint::ToSharedString;

mod clock;

slint::include_modules!();

fn main() -> Result<(), slint::PlatformError>{
    let window = MainWindow::new()?;
    let mut timer = clock::Time {
        minute: 15,
        second: 0,
    };
    
    timer.dec_second();

   // How to have this command running after window.run() has been invoked?
    window.set_time(timer.to_str().to_shared_string());

    window.run()
}

[guimath]

For synchronous, you could have a timer in your slint app that triggers a callback that you can then use to do whatever in rust.

In your MainWindow in slint :

callback refresh();

timer := Timer {
    interval: 1s;
    running: true;
    triggered() => {
        refresh();
    }
}

and then in rust before your window.run() :

window.on_refresh({
    let window_handle = window.as_weak();
    move || {
        let window = window_handle.unwrap();
        timer.dec_second();
        window.set_time(timer.to_str().to_shared_string());
    }
});

This is probably not the fastest way to do it, and if thats not enough you should indeed look into asynchronous with a timer directly in rust but thats a bit more work...

[burumdev]

You can spawn an async local thread for this:

https://docs.slint.dev/latest/docs/rust/slint/fn.spawn_local

And for simple timer notifications from the backend, you can use tokio's notify without spinning a tokio runtime:

https://docs.rs/tokio/latest/tokio/sync/struct.Notify.html

let app_weak = app.as_weak();
slint::spawn_local(async move {
    let appw = app_weak.clone().unwrap();
    loop {
        // Wait for values to be available
        self.notify.notified().await;
        appw.increase_timer_count();
    }
}).unwrap()