alv tree

hi abapers !

i know how to develop objects working with classes.

am able to create interactive reports using classes..!

i,e double click, hot spot click etc.

could any one tell me the prerequisite for alv tree using class.

what are the methods and events required for this ?

decelerations for alv tree.!

can any one provide pdf materials for ALV trees classes ?

Thanks & regards,

Bala.