Interface definition for callbacks to be invoked when the transformation of the node changes.
The originating node is the most top-level node in the hierarchy that triggered the node
to change. It will always be either the same node or one of its' parents. i.e. if node A's
position is changed, then that will trigger
onTransformChanged(Node, Node) to be
called for all of it's descendants with the originatingNode being node A.
|the node that changed
|the node that triggered the transformation to change