AIDL2 is a replacement for Google's aidl tool. Unlike it's predecessor, it is based on Java annotation processing facilities.
It is still at alpha stage of development, but all planned features are already implemented:
The idea behind the decorator pattern is to decouple responsibilities from the parent class into reusable components. Individual decorators can then be attached to otherwise empty parent classes to do a single job. This allows a simple java class to have multiple and dynamic inheritance. In order to make this pattern scalable with minimal boilerplate, an easy to use code-generation library was created to automate most of its creation.