Hi all!
 i'm developing a java application that let the user to setup and
 simulate physical experiments. I want the user to be able to place force
 arrow in a diagram and then start the simulation. My problem is that i
 can't find a canvas that let me place things like arrow, circle and
 rectangle on it.  I want also to move or modify their properties. I can
 program it byt myself of course (using a jpanel) but using an already
 made component (GPL as my program, of course!) will be the best now for
 me. Any advice?

nelson