vertex = pickSupport.getVertex(ip.getX(), ip.getY());
if(vertex != null) {
if(pickedState.isPicked(vertex) == false) {
pickedState.clearPickedVertices();
pickedState.pick(vertex, true);
vv.fireStateChanged();
}
// layout.getLocation applies the layout transformer so
// q is transformed by the layout transformer only
Point2D q = layout.getLocation(vertex);
// transform the mouse point to graph coordinate system