AsyncDisplayKit is an asynchronous UI framework and performance library for iOS. It provides a collection of performant alternatives to standard views, allowing developers to build responsive interfaces by offloading layout and rendering tasks to background threads.
The framework is centered around a declarative layout engine based on a flexbox model, which calculates element positions and sizes asynchronously. It utilizes a node-based abstraction to wrap native views, enabling the instantiation and configuration of UI hierarchies on background threads to prevent main thread blocking.
The system covers extensive performance optimization areas, including asynchronous image decoding, text rasterization, and proactive content preloading based on viewport proximity. It includes specialized support for high-performance scrolling lists with automatic row height calculation and a comprehensive set of UI components for rich text rendering and interactive controls.
Additional capabilities include multimedia handling for animated GIFs and video, network image management with multi-tier caching, and developer tools for debugging layout hierarchies and visualizing interaction areas.