Keeping relationships during a drag event.

[Glen Bojsza]

The basic description of what I am working to achieve is the following.

I have 2 images (car1 and car2) that are connected by a line.

When the user drags car1 to a different position on the card the
line's points are updated and to the user it appears that the images
are still connected (the idea is a "sticky" line.

What I am trying to figure out is that  I want a field  to be placed
at the center on the line and it needs to maintain that relationship
with the line whenever  the image locations are changed.

The problem is that as the user drags an image around the line and
it's associated field need to move / update smoothly.

I am looking at grouping the line and field verses taking the points
of the line and recalculating the new location of the field.

I was hoping someone would have some experience in this area.

thanks,

Glen