We present a novel approach for synthesizing robust relational layouts from examples. Given an application design consisting of a set of views and their location on screen, we synthesize a relational layout that when rendered, places the components at that same location.

We present an end-to-end system, called InferUI, that addresses the above challenge in the context of Android. The system is based on the following technical contributions: (i) a complete formalization of the latest and most efficient ConstraintLayout class, capturing a rich set of relational constraints, (ii) a set of robustness properties designed to prevent common layout generalization errors, (iii) a synthesis algorithm that produces relational layouts that generalize across multiple screen sizes and resolutions, and (iv) a probabilistic model of constraints which guides the synthesizer towards layouts preferred by developers.

Our evaluation shows that InferUI is practically effective: it successfully synthesizes real world complex layouts obtained from top 500 GitHub and top 500 Google Play Store applications, succeeds in 100% of cases when synthesizing layouts for a single device, and correctly generalizes 92% of views across multiple devices, all without requiring additional specifications.