How to make a window blurry? win10/11

[ohnjec]

Hi, I'm making a Slint app with Rust and trying to make the background of my window blurry, which I can't seem to do with any built-in property. I've tried using window_vibrancy, which was mentioned in other question posts, but I'm new to Rust and don't have the ability to implement it correctly.
Can someone show me a different way to do this or guide me through?

.rs:

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

use std::{error::Error, process};
slint::include_modules!();

fn main() -> Result<(), Box<dyn Error>> {
    let ui = IPv4RANGER::new()?;
    let window = ui.as_weak().unwrap();
    #[cfg(target_os = "windows")]
    let mut fullscreen = false;
    ui.on_quit({
        move || {
            process::exit(0);
        }
    });
    ui.on_fullscreen({
        move || {
            fullscreen = !fullscreen;
            window.window().set_fullscreen(fullscreen);
        }
    });
    ui.run()?;
    Ok(())
}

.slint:

import { Button, VerticalBox} from "std-widgets.slint";
// import "./consola.ttf";

export component IPv4RANGER inherits Window {
    title: "RANGER";
    width: 360px;
    height: 500px;
    no-frame: true;
    always-on-top: false;
    full-screen: false;
    // default-font-family: "Consolas";
    // icon: @image-url("icon.png");
    background: transparent;
    callback quit();
    callback fullscreen();
    FocusScope { 
        key-pressed(event) => {
            if(event.text == Key.Escape) {
                root.quit();
                return accept;
            }
            else if(event.text == Key.Shift) {
                root.fullscreen();
                return accept;
            }
            else {
                return reject;
            }
        }
        VerticalLayout {
            Rectangle {background: #232323; height: 6%; border-top-left-radius: 10px; border-top-right-radius: 10px;}
            Rectangle {background: #292929;  height: 94%; border-bottom-left-radius: 10px; border-bottom-right-radius: 10px;
                    HorizontalLayout {width: 240px;
                        VerticalLayout {horizontal-stretch: 0.5;
                        Rectangle {background: transparent; padding-top: 10px; height: 60px;
                            Text {font-size: 30px;
                                text: "IPv4 RANGER";
                            }
                        }
                        Rectangle {background: #232323; padding-bottom: 10px; width: 240px; border-radius: 10px;
                        }
                        Rectangle {background: transparent; padding-top: 10px; height: 30px;
                            Text {
                                text: "ALPHA";
                            }
                        }
                    }
                }
            }
        } 
    }
}

.toml:

[package]
name = "slint-rust-template"
version = "0.1.0"
edition = "2021"

[dependencies]
slint = "1.8.0"
winit = "0.30.7"

[build-dependencies]
slint-build = "1.8.0"

[ogoffart]

Maybe possible using native or private API.

You can get a native window handle with the window_handle function. Then maybe some native Windows 11 API

Another possibility is to use the i-slint-backend-winit private API to get a winit handle and try to call set_system_backdrop

Tracking issue: #2339

[ohnjec]

Answer:

add this dependency to cargo.toml, make sure it's the same version as the slint dependency

i-slint-backend-winit = "1.8.0"

and add this code to main.rs

ui.window().with_winit_window(|winit_win: &i_slint_backend_winit::winit::window::Window| {
    winit_win.set_system_backdrop(TransientWindow);
    // replace 'ui' with whatever variable you use to declare the window with
});

Links that helped me:
https://docs.rs/winit/latest/winit/platform/windows/trait.WindowAttributesExtWindows.html#tymethod.with_system_backdrop
https://docs.rs/winit/latest/winit/platform/windows/enum.BackdropType.html

[ogoffart]

i-slint-backend-winit = "1.8.0"

It should be

i-slint-backend-winit = "=1.8.0"

With = before the version number

because there is no semver guarantees for private API