Android Display System: From App to Screen

This article provides a brief analysis of the process from when an App draws a frame to how that frame reaches the screen and is ultimately seen by the human eye. It correlates each step in this process with its manifestation in systrace, aiming to give readers a macro-level understanding of the Android display system's rendering pipeline.

The article guides readers through the data flow of UI information in the display system, analyzing the basic steps involved in App, SurfaceFlinger (SF), Hardware Composer (HWC), and hardware screen processing of UI data. While the Android display system is highly complex with many modules and continuously evolving through updates and optimizations, the fundamental data flow direction remains constant. This article aims to help readers develop a macro-level understanding of the display system, though detailed processing mechanisms require further exploration through source code reading.

The content is based on Android S and includes references to Android source code, Android graphics system summaries, and Android Systrace fundamentals.