Request repaint on stdout/stderr changes

[barafael]

Proof-of-concept fix for #51, using an unsafe static mut CTX to save the egui::Context.

Doing this right could be done by adding a ctx field to the Klask type, however, this may be a big conceptual change? Also, egui::Context does not impl std::fmt::Debug, so it breaks the #[derive(Debug)] on Klask.

Let me know what you think when you have the time :)

[MichalGniadek]

Thanks for the PR! :) Could you explain why this is needed and why the issue happens? Why does the GUI not refresh on stdout changes?

Either way I think it would be better to either use once_cell or something similar or put the ctx in Klask instead of using unsafe

[barafael]

Hi Michal,
here's a minimal example showing the issue:

use std::{thread, time::Duration};

use clap::Parser;
use klask::Settings;

#[derive(Debug, Parser)]
struct Args {
    #[clap(short)]
    verbose: bool,
}

fn main() {
    klask::run_derived::<Args, _>(Settings::default(), |_| {
        for _ in 0..5 {
            println!("hello");
            thread::sleep(Duration::from_millis(500));
        }
    });
}

[barafael]

This new fix gets away without unsafe and once_cell. We fixed it collaboratively in the Rust Nuremberg Meetup group :)

This fixes another slight bug, namely that the "Run" and "Kill" buttons did not correctly update when the application exited.

By calling request_repaint one last time when stdout or stderr close, the button reappears even when the mouse is not moved. This of course only happens if the application really closed, not if it is for some reason still running.

[MichalGniadek]

This new fix gets away without unsafe and once_cell

That's amazing! Thank you :)