layer-shika

🦌

"A cute layer of abstraction where Slint UIs grow antlers and become cute Wayland shells."

Main repo | Mirror | Temp mirror (github)

⚠️ WORK IN PROGRESS ⚠️

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.

Please note that this library is currently in early development and is not yet ready for production use.

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

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 framework 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

Known Limitations:

• API may change before 1.0
• 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, but if you want you can experiment with the current version. 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
...
...

See the examples README for detailed usage instructions and patterns.

Usage

If you want to use it now, use this repo as dependency instead of crates.io outdated versions.

First Stable Release

The aim is to have the first stable release by the end of 2025, with a focus on core functionality and API stability.

Stay tuned!

Contributing

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!