Prefuse Toolkit: dynamically adding nodes and edges

Does anyone have experience with the prefuse graph toolkit? Is it possible to change an already displayed graph, ie. add/remove nodes and/or edges, and have the display correctly adapt?

For instance, prefuse comes with an example that visualizes a network of friends:

http://prefuse.org/doc/manual/introduction/example/Example.java

What I would like to do is something along the lines of this:

// -- 7. add new nodes on the fly -------------------------------------
new Timer(2000, new ActionListener() {
    private Node oldNode = graph.nodes().next(); // init with random node

    public void actionPerformed(ActionEvent e) {
        // insert new node //
        Node newNode = graph.addNode();

        // insert new edge //
        graph.addEdge(oldNode, newNode);

        // remember node for next call //
        oldNode = newNode;
    }
}).start();

But it doesn't seem to work. Any hints?

Solution

As pointed out in my other post, the reason new nodes and edges are not visible in the original example is that the colors etc. for the nodes are not set correctly. One way to fix this is to explicitly call vis.run("color"); whenever a node or edge was added.

Alternatively, we can ensure that the color action is always running, by initializing the ActionList to which we add it (called "color" in the original example) slightly differently:

instead of

ActionList color = new ActionList();

we could write

ActionList color = new ActionList(Activity.INFINITY);

This keeps the action list running indefinitely, so that new nodes/edges will automatically be initialized for their visual appearance.

However, it is unclear to me whether this would actually be the preferred method - for things like a dynamic layout action (e.g. ForceDirectedLayout), such a declaration makes perfect sense, but for colors it seems to me that a constantly running coloring action is mostly overhead.

So, perhaps the previously posted solution of just running the "color" action explicitly (but only once) whenever the graph gets extended, might be the better choice...