To show the user something, you could use the SpringLayout's Progress delegate to update a progressbar, or run iterations from a timer as shown in the SpringLayout sample project.

Since it is of polynomial complexity, SpringLayout will work very slow if you have more than a few hundred nodes. For the next release we are preparing a partitioning algorithm that applies layouts on smaller parts of the diagram and then treats each part as a separate node to arrange the full diagram.

For example, that arranges a graphs of 900 nodes by applying a layout on each 30-nodes subgraph and then arranges the whole diagram as each of the subgraphs was a node (so again 30 nodes). This arranges everything in 6-7 seconds. If you are interested in this, I can send you our work in progress to play with.

Stoyan