Posts Tagged ‘QML’
[OxidizeConf2024] Exploring Slint as a Rust Alternative to QML for GUI Development
The Evolution of GUI Development
In the ever-evolving realm of graphical user interface (GUI) development, the quest for robust, safe, and efficient tools is paramount. David Vincze, a senior software engineer at Felgo, presented a compelling exploration of Slint as a Rust-based alternative to QML at OxidizeConf2024. With a background steeped in C++ and Qt, particularly in automotive instrument clusters, David shared his insights into how Slint offers a fresh perspective for developers accustomed to QML’s declarative approach within the Qt framework. His presentation illuminated the potential of Slint to address the limitations of QML, particularly its reliance on C++ and JavaScript, which can introduce runtime errors that challenge developers in safety-critical environments.
QML, a mature language with over a decade of use, has been a cornerstone for cross-platform GUI development, enabling developers to write a single codebase that runs on embedded, mobile, desktop, and web platforms. Its JSON-like syntax, coupled with reactive property bindings and JavaScript logic, simplifies prototyping and maintenance. However, David highlighted the inherent risks, such as performance bottlenecks due to JavaScript’s runtime interpretation and the dependency on the extensive Qt ecosystem, which can entail licensing costs. Slint, a newer toolkit built with Rust, emerges as a promising alternative, compiling to native code to catch errors at build time, thus enhancing reliability for embedded systems.
Comparing Slint and QML
David’s analysis centered on a practical comparison between Slint and QML, drawing from a demo weather application and home automation UI developed at Felgo. This project, available on Felgo’s GitHub as the Rusty Weather App, reimplemented a QML-based application in Slint, showcasing its multiplatform capabilities on desktop, embedded Raspberry devices, and Android. The comparison revealed striking similarities in their declarative syntax, with both languages using component-based structures to define UI elements. However, Slint’s code is notably more compact, and its components can be exported to native code, offering greater integration flexibility compared to QML’s C++-centric approach.
A key differentiator is Slint’s compilation to native code, which eliminates runtime errors common in QML’s JavaScript logic. This is particularly advantageous for embedded systems, where performance and reliability are critical. David demonstrated how Slint’s lightweight runtime and reactive property bindings mirror QML’s strengths but leverage Rust’s memory safety to prevent common programming errors. However, Slint lacks some of QML’s advanced features, such as multimedia support, 3D rendering, and automated UI testing, which are still in development. Despite these gaps, Slint’s rapid evolution, with frequent releases, signals its potential to rival QML in the future.
Challenges and Opportunities in Transitioning
Transitioning from QML to Slint presents both opportunities and challenges. David emphasized Slint’s benefits, including its integration with Rust’s ecosystem, which offers a robust package manager (Cargo) and seamless cross-compilation. The Slint VS Code extension, with its live preview feature, accelerates development by allowing real-time UI modifications without recompilation. This contrasts with QML’s reliance on tools like Qt Creator, which, while comprehensive, tie developers to the Qt ecosystem. Slint’s open-source nature and multi-language APIs (supporting Rust, C++, JavaScript, and Python) further enhance its appeal for diverse projects.
However, David acknowledged challenges, particularly in areas like internationalization, where Slint’s reliance on the Gettext library complicates translation processes compared to Qt’s well-established framework. Features like multi-window support and internal timers are also underdeveloped in Slint, posing hurdles for developers accustomed to QML’s mature ecosystem. Despite these, David advocated for Slint’s adoption in Rust-centric projects, citing its predictability and performance advantages, especially for embedded development. The community’s active development and planned UI testing support suggest that Slint’s limitations may soon be addressed, making it a compelling choice for forward-thinking developers.