Implementing adapters is one of the most frequent tasks for an Android developer. It’s the base for every list. Looking at apps, lists are the base of most apps. The schema we follow to implement list views is often the same: a View with an adapter that holds the data. Doing this all the time can make us blind to what we are writing, even to ugly

Choreographer is the one which acts like a interface between application view system and lower layer display system for rendering the views. ViewRootImpl is the ViewParent or root below which only Activity window DecorView will be attached. All the view layouts set by the activity through setContentView() will attached the DecorView whose parent is ViewRootImpl. Actually ViewRootImpl is not a View its just a ViewParent which handled and manages the View Hierarchies for displaying, handling input events etc.

In Android What is VSYNC and its usage? VSYNC is the event posted periodically by the kernal at fixed interval where the input handling, Animation and Window drawing happening synchroniiously at the same VSYNC interval. Below have given the detail explanation about the VSYNC event before VSYNC is introduced and after VSYNC is introduced. Before VSYNC is introduced: Before VSYNC is introduced then there was no synchronization happening for Input, animation and draw.