if(e.getStateChange() == ItemEvent.SELECTED) {
LayoutTransition<String,Integer> lt =
new LayoutTransition<String,Integer>(vv, treeLayout, radialLayout);
Animator animator = new Animator(lt);
animator.start();
vv.getRenderContext().getMultiLayerTransformer().setToIdentity();
vv.addPreRenderPaintable(rings);
} else {
LayoutTransition<String,Integer> lt =
new LayoutTransition<String,Integer>(vv, radialLayout, treeLayout);