question: private int estimateDist ( AreaPanel ap1 , AreaPanel ap2 ) { int yDist = Math . abs ( ap1 . getCenterY ( ) - ap2 . getCenterY ( ) ) ; int xDist = Math . abs ( ap1 . getCenterX ( ) - ap2 . getCenterX ( ) ) ; if ( xDist < ( yDist > > 1 ) || yDist < ( xDist > > 1 ) ) return xDist + yDist ; return ( int ) ( ( xDist + yDist ) * 7l / 10 ) ; }
target:  This calculates a really cheap estimate of distance in meters between the center of the aps. It is only used to choose a  proper size of the view node, so we really don't care much.