do you want to drag around an object on the screen ? take a look at MouseListener and MouseMotionListener. You can subscribe for events and are able to find out were the mouse pointer currently is. then you could check if the current point is in one of those regions you need to check.
Let me explain . i have to create a mobile node( it is enough to be a data structure) i will first assign a location(x,y) .then randomly i have to move the mobile node to (x+dx,y+dy) in any direction. a sniffer like datastructure will detect the movement and say whether mobile node has crossed its signal range. how shall i proceed. i need some basic concept. it is not neccesary to show graphically.