I want to write a custom view that requires some button with a speicific id to be present (to be able to be found by id), as in ListActivity android.R.id.list must be present, how do i do the same with a custom id of my own?

I plan on reusing this view in an Android lib for several use cases, but all of them must declare some specific view with specific id so that i can find it by id in the lib code and manipulate it for later use in using Applications...