... project. All the library files live in library. The library also uses some Java 8 features, which Android Studio will need to transpile. The library follows the same API as other pickers in the Android framework. The library contains 2 layout versions for each picker. Version 1 is the original layout. It is based on the layout google used in the kitkat and early material design era. And version 2 is based on the guidelines google posted when launching android marshmallow.