Drag and Drop listener on Canvas

Is it possible to add a EventListener to the com.jme.Canvas

or to extend the Canvas and have it be implemented as a DropTargetListener.

I have tried to do both, but to no avail.

Basically, I want to be able to use a JTree on the left and drag and drop models onto the Canvas.  I have all the drag and drop support built into the JTree, but when an item is dragged onto the canvas the 'highlight' does its not-able to copy routine.  I know I could work around it logically and make drag and drop work (not as intended) but the UI not-copy animation kinda makes me nervous; people are used to certain UI animations and I don't want to cause confusion by having erroneous UI 'hints'.