# Winio
Winio is a single-threaded asynchronous GUI runtime.
It is based on [`compio`](https://github.com/compio-rs/compio), and the GUI part is powered by Win32, Qt, GTK and Cocoa.
All IO requests could be issued in the same thread as GUI, without blocking the user interface!
## Quick start
Winio follows ELM-like design, inspired by [`yew`](https://yew.rs/) and [`relm4`](https://relm4.org/).
The application starts with a root `Component`:
```rust
use winio::prelude::*;
fn main() {
App::new("rs.compio.winio.example").run::<MainModel>(());
}
struct MainModel {
window: Child<Window>,
}
enum MainMessage {
Noop,
Close,
}
impl Component for MainModel {
type Event = ();
type Init<'a> = ();
type Message = MainMessage;
fn init(_init: Self::Init<'_>, _sender: &ComponentSender<Self>) -> Self {
// create & initialize the window
init! {
window: Window = (()) => {
text: "Basic example",
size: Size::new(800.0, 600.0),
}
}
window.show();
Self { window }
}
async fn start(&mut self, sender: &ComponentSender<Self>) -> ! {
// listen to events
start! {
sender, default: MainMessage::Noop,
self.window => {
WindowEvent::Close => MainMessage::Close,
}
}
}
async fn update(&mut self, message: Self::Message, sender: &ComponentSender<Self>) -> bool {
// update the window
self.window.update().await;
// deal with custom messages
match message {
MainMessage::Noop => false,
MainMessage::Close => {
// the root component output stops the application
sender.output(());
// need not to call `render`
false
}
}
}
fn render(&mut self, _sender: &ComponentSender<Self>) {
self.window.render();
// adjust layout and draw widgets here
}
}
```