/// <summary>
/// Initializes the graph instance setting default styles
/// and creating a small sample graph.
/// </summary>
protected virtual void InitializeGraph()
{
IGraph graph = Graph;
// load a sample graph
new GraphMLIOHandler().Read(graph, "Resources/sample.graphml");
// set some defaults
graph.NodeDefaults.Style = Enumerable.First(graph.Nodes).Style;
graph.NodeDefaults.ShareStyleInstance = true;
// we start with a simple run of OrganicLayout to get a good starting result
// the algorithm is optimized to "unfold" graphs quicker than
// interactive organic, so we use this result as a starting solution
var initialLayout = new OrganicLayout {
MinimumNodeDistance = 50
};
graph.ApplyLayout(initialLayout);
// center the initial graph
GraphControl.FitGraphBounds();
movedNodes = new List <INode>();
// we wrap the PositionHandler for nodes so that we always have the collection of nodes
// that are currently being moved available in "movedNodes".
// this way we do not need to know how the node is moved and do not have to guess
// what elements are currently being moved based upon selection, etc.
graph.GetDecorator().NodeDecorator.PositionHandlerDecorator.SetImplementationWrapper(
(item, implementation) => new CollectingPositionHandlerWrapper(item, movedNodes, implementation));
// create a copy of the graph for the layout algorithm
LayoutGraphAdapter adapter = new LayoutGraphAdapter(graphControl.Graph);
copiedLayoutGraph = adapter.CreateCopiedLayoutGraph();
// create and start the layout algorithm
layout = StartLayout();
WakeUp();
// register a listener so that structure updates are handled automatically
graph.NodeCreated += delegate(object source, ItemEventArgs <INode> args) {
if (layout != null)
{
var center = args.Item.Layout.GetCenter();
layout.SyncStructure(true);
//we nail down all newly created nodes
var copiedNode = copiedLayoutGraph.GetCopiedNode(args.Item);
layout.SetCenter(copiedNode, center.X, center.Y);
layout.SetInertia(copiedNode, 1);
layout.SetStress(copiedNode, 0);
layout.WakeUp();
}
};
graph.NodeRemoved += OnStructureChanged;
graph.EdgeCreated += OnStructureChanged;
graph.EdgeRemoved += OnStructureChanged;
}
/// <summary>
/// Executes the module on the given graph using the provided context.
/// </summary>
/// <remarks>
/// The layout will be calculated <see cref="RunInBackground">optionally</see>
/// in a separate thread in method <see cref="RunModuleAsync"/>.
/// </remarks>
/// <param name="graph">The graph to execute on.</param>
/// <param name="newContext">The context to use. This method will query a <c>ISelectionModel<IModelItem></c></param>
/// for the selected nodes and edges and the <c>GraphControl</c> to morph the layout.
protected virtual async Task StartWithIGraph(IGraph graph, ILookup newContext)
{
this.graph = graph;
if (ShouldConfigureTableLayout())
{
PrepareTableLayout();
}
ISelectionModel <IModelItem> selectionModel = newContext.Lookup <ISelectionModel <IModelItem> >();
LayoutGraphAdapter adapter = new LayoutGraphAdapter(graph, selectionModel);
this.layoutGraph = adapter.CreateCopiedLayoutGraph();
ILookup additionalLookup = Lookups.Single(layoutGraph, typeof(LayoutGraph));
ILookup wrappedLookup = Lookups.Wrapped(newContext, additionalLookup);
try {
ICompoundEdit compoundEdit = graph.BeginEdit("Layout", "Layout");
CheckReentrant(wrappedLookup);
ConfigureModule();
if (RunInBackground)
{
// without the LayoutExecutor helper class on the layout graph side of things, we register the aborthandler
// to the layout graph with the utility method provided by AbortHandler
var abortHandler = AbortHandler.CreateForGraph(layoutGraph);
// now create the dialog that controls the abort handler
abortDialog = new AbortDialog {
AbortHandler = abortHandler, Owner = Application.Current.MainWindow
};
// start the layout in another thread.
var layoutThread = new Thread(async() => await RunModuleAsync(wrappedLookup, graph, compoundEdit));
// now if we are not doing a quick layout - and if it takes more than a few seconds, we open the dialog to
// enable the user to stop or cancel the execution
var showDialogTimer = new DispatcherTimer(DispatcherPriority.Normal, abortDialog.Dispatcher)
{
Interval = TimeSpan.FromSeconds(2)
};
showDialogTimer.Tick += delegate {
// it could be that the layout is already done - so check whether we still
// need to open the dialog
var dialogInstance = abortDialog;
if (dialogInstance != null)
{
// open the abort dialog
dialogInstance.Show();
}
// we only want to let it go off once - so stop the timer
showDialogTimer.Stop();
};
// kick-off the timer and the layout
showDialogTimer.Start();
layoutThread.Start();
}
else
{
await RunModuleAsync(wrappedLookup, graph, compoundEdit);
}
} catch (Exception e) {
FreeReentrant();
TableLayoutConfigurator.CleanUp(graph);
OnDone(new LayoutEventArgs(e));
//optionally do something here...
}
}
