iced_layershell

Warning: This library is not intended for general use. It is specifically built for ashell and will not accept feature requests or bug reports unrelated to ashell. If you need a general-purpose iced layer shell backend, consider iced-layershell or the pop-os/iced fork.

Wayland layer shell backend for iced 0.14. Built to power ashell, a Wayland status bar.

AI-assisted development

This library was developed with the assistance of AI coding agents. The architecture, implementation, code reviews, and documentation were produced through human-AI collaboration. All code has been reviewed and tested by the maintainer.

What this is

A thin bridge between iced's widget/rendering system and the Wayland layer shell protocol via smithay-client-toolkit. It replaces iced_winit for applications that need layer shell surfaces (panels, overlays, status bars) instead of regular windows.

This library is tailored for ashell. It implements exactly the features ashell needs and nothing more. It is not a general-purpose iced backend and does not aim to support every layer shell use case.

Design goals

• Zero idle CPU -- the event loop blocks when nothing happens. No polling, no busy loops.
• Standard iced -- works with upstream iced 0.14 releases, no fork required.
• Frame-synced rendering -- uses Wayland frame callbacks to prevent overrendering.
• Multi-surface -- supports multiple layer surfaces (e.g. status bar + dropdown overlay).

Features

• Layer shell surface management (create, destroy, configure anchor/layer/size/margin/exclusive zone)
• Keyboard input with client-side repeat and physical key mapping, pointer, touch, and scroll events
• Full iced runtime action handling (clipboard read/write, widget focus, font loading)
• HiDPI support with configurable application scale factor
• Output (monitor) tracking with connect/disconnect subscriptions
• Persistent widget UIs with iced's UserInterface caching
• Compositor-side background blur (ext-background-effect-v1) via blur_container

Usage

use iced_layershell::*;

fn main() -> Result<(), Error> {
    application(boot, update, view)
        .layer_shell(LayerShellSettings {
            anchor: Anchor::TOP | Anchor::LEFT | Anchor::RIGHT,
            layer: Layer::Top,
            exclusive_zone: 40,
            size: Some((0, 40)),
            ..Default::default()
        })
        .subscription(subscription)
        .theme(|state| state.theme.clone())
        .run()
}

See examples/ for working demos.

Background blur

blur_container is a container that additionally asks the compositor to blur the wallpaper behind it, using the corner radius of its own style to shape the blurred region:

use iced_layershell::{Border, Theme, container, widget::blur_container};

blur_container(content)
    .padding(8)
    .style(|theme: &Theme| container::Style {
        background: Some(theme.palette().background.scale_alpha(0.6).into()),
        border: Border::default().rounded(12),
        ..container::Style::default()
    })

Blur is only visible behind a translucent background, so give the container one. The region is recomputed as the widget draws and pushed to the compositor only when it changes. On a compositor that doesn't implement ext-background-effect-v1 (or that reports no blur capability) this is exactly a container and costs nothing.

blur(radius, content) is a shorthand for a blur_container that draws no background of its own — use it when something else already paints the rounded surface.

What is NOT supported

Features that ashell doesn't need are intentionally omitted:

• Drag and drop
• Popups / xdg-popup
• Session lock surfaces
• Subsurfaces
• Window actions (minimize, maximize, resize, etc.)