picking up mouse-drag events

[chrispi@merle.acns.nwu.edu (christian e. crone)]

are there variables that holds the beginning and current position of a drag
event (for example, as in selecting a group of objects)?  it seems like
*mouse-view*, etc. are bound to the click-down point.

is there a method which handles such "selections" (which can be specialized)?
if i were to try to make my own multi-view selection routine, where would it
best fit?

thanks...