An Improved User Interface Checking Function Considering Multiple Platforms for Flutter Programming Learning Assistant System

To support learning Dart programming on the Flutter cross-platform development framework, we have developed the Flutter Programming Learning Assistant System (FPLAS). FPLAS incorporates a Docker-based Flutter environment with Visual Studio Code and five foundational exercise projects. The user interface checking function was implemented to automatically assess students' source codes by executing them and comparing the resulting UI images on the web platform with the correct reference images. However, we only considered the web platform on Windows in the user interface checking function, although the same Dart code may generate different UI images depending on the target platform and operating system. It is essential to account for these variations in the function. In this paper, we improve the UI checking function to absorb the differences in the output UI image across multiple platforms including iOS, Android, and web, by preparing correct images for each platform. For evaluations, we applied the proposal to the UI image files generated in the five exercises and confirmed the validity and effectiveness.