How to sense (or animate view on) change of selection in Gallery

I am looking to extend the Android Gallery view. How is it possible to sense a change in the selected item?

I would have thought it could be done by extending one or both of the setSelection methods. Yet when I do so, and change select开发者_运维百科ion by a tap or swipe or D-pad press, I do not find either of the setSelection methods being called.

AdapterView has a nested OnItemSelectedListener class, but there seems to be no way to supply my own listener. getOnItemSelectedListener() is declared final, and there is no setOnItemSelectedListener().

My main reason for wanting to extend Gallery, actually, is to provide some animation as views move into or out of selection. Any other suggestions on how to accomplish that...?