layer-shika

Oh deer! 🦌 You've stumbled upon layer-shika, a Rust library providing Wayland layer shell integration with Slint UI. Create overlay windows, status bars, panels, popups, and more, that integrate seamlessly with Wayland compositors.

[!CAUTION] This library is currently in early development and is not yet ready for production use. API may change before 1.0.

[!NOTE] Coming soon: A complete Wayland shell built on top of layer-shika! Stay tuned for updates.

Features

• Slint Integration: Runtime .slint file compilation via slint-interpreter or compile-time code generation. Support via pre-compiled is planned.
• Multi-Surface Support: Create multiple independent layer shell windows, each with its own configuration and lifecycle
• Flexible Configuration: Both fluent builder API and declarative configuration support
• Comprehensive Popup System: Full xdg-popup protocol implementation with multiple positioning modes, grab support, and content-based sizing (rework in progress)
• Multi-Output Support: Per-monitor component instances with flexible output policies (primary only, all outputs, specific outputs)
• Event Loop Integration: Custom event sources (timers, channels, file descriptors) via calloop integration
• Clean-like Architecture: Organized as a Cargo workspace with clear separation of concerns (domain, adapters, composition)
• HiDPI Support: Configurable scale factors for high-resolution displays
• Session Lock Support: ext-session-lock-v1 protocol integration for lock screens

Architecture

layer-shika is organized as a Cargo workspace with three crates:

• domain (crates/domain/): Core domain models, value objects, and port trait definitions. No external dependencies.
• adapters (crates/adapters/): Concrete implementations for Wayland (smithay-client-toolkit), rendering (femtovg + EGL), and platform integration.
• composition (crates/composition/): Public API layer providing Shell-based API, builder patterns, and system integration.

This clean-like architecture enables flexibility, and clear dependency boundaries (composition → adapters → domain).

Current Status

What's Working:

• Multi-surface shell with builder and declarative configuration APIs
• Wayland layer shell protocol (wlr-layer-shell) via smithay-client-toolkit
• Full xdg-popup protocol support with flexible positioning and sizing
• EGL context management with femtovg renderer integration
• Multi-output detection, tracking, and per-output component instances
• Event handling framework with ShellEventContext and ShellControl
• Custom event loop integration (timers, channels, file descriptors)
• HiDPI scale factor support
• Session lock support via ext-session-lock-v1 protocol

[!WARNING] Known Limitations:

• Documentation is work in progress
• Some edge cases may not be fully tested
• It's recommended to wait for a stable release before using this library in production projects

However, if you want to experiment with the current version, feel free to do so! Development is trying to be as fast as a running skippy deer!

Quick Start

Check out the examples/ directory for comprehensive demonstrations. Each example includes detailed documentation and can be run with:

cargo run -p simple-bar
cargo run -p multi-surface
cargo run -p declarative-config
cargo run -p session-lock
...

See the examples README for detailed usage instructions and patterns.

Usage

[!IMPORTANT] If you want to use it now, use this repo as a dependency instead of crates.io versions.

First Stable Release

The aim is to have the first stable release by the end of February 2026, with a focus on core functionality and API stability.

Stay tuned!

Contributing

[!TIP] As the library is in a very early stage, it's recommended to open an issue to discuss ideas or proposed changes before submitting contributions. The project doesn't bite, it's not that kind of deer!