custom draggable titlebar (wayland compatible)

[Starchaser0]

it took me a while to figure this one out (im kind of a rust noob lol), so i thought id share my findings :)

Cargo.toml

[package]
name = "custom_titlebar"
version = "0.1.0"
edition = "2021"

[dependencies]
slint = { version = "1.14.1", features = ["unstable-winit-030"] }

[build-dependencies]
slint-build = "1.14.1"

[profile.release]
codegen-units = 1
lto = true

main.rs

use slint::winit_030::WinitWindowAccessor;
slint::include_modules!();

fn main() -> Result<(), Box<dyn std::error::Error>> {
    slint::BackendSelector::new()
        .backend_name("winit".into())
        .select()?;

    let ui = AppWindow::new()?;
    let ui_handle = ui.as_weak();

    ui.on_start_drag(move || {
        let handle = ui_handle.clone();
        slint::spawn_local(async move {
            let window = handle.unwrap();
            let winit_window = window.window().winit_window().await.unwrap();
            let _ = winit_window.drag_window();
        })
        .unwrap();
    });

    ui.run()?;

    Ok(())
}

app-window.slint

import { VerticalBox } from "std-widgets.slint";

export component AppWindow inherits Window {
    no-frame: true;

    callback start-drag();

    VerticalBox {
        titlebar := Rectangle {
            background: blue;
            height: 25px;

            drag_area := TouchArea {
                pointer-event(event) => {
                    if (event.button == PointerEventButton.left) {
                        root.start-drag();
                    }
                }
            }
        }

        Text {
            text: "window with custom draggable titlebar :D";
        }
    }
}