public static void ToogleFoldingOfVisibleClusters(this IGraphPresentation presentation)
{
Contract.RequiresNotNull(presentation, nameof(presentation));
var transformation = presentation.ClusterFolding();
var visibleClusters = presentation.TransformedGraph().Clusters
.Where(presentation.Picking.Pick)
.Select(c => c.Id)
.ToList();
// any visible cluster folded?
if (visibleClusters.Any(transformation.Clusters.Contains))
{
// safe to pass nodes not known to transformation
transformation.Remove(visibleClusters);
}
else
{
transformation.Add(visibleClusters);
}
}