/// <summary>
/// Creates a large random graph to give the layout algorithms something to chew.
/// </summary>
private static void BuildGraph(IGraph graph)
{
graph.Clear();
// Create 400 nodes
INode[] nodes = new INode[400];
for (int i = 0; i < nodes.Length; i++)
{
nodes[i] = graph.CreateNode();
}
// Connect the nodes randomly
Random random = new Random(0);
for (int i = 0; i < nodes.Length; i++)
{
int edgeCount;
if (random.Next(10) == 0)
{
edgeCount = 4 + random.Next(5);
}
else
{
edgeCount = random.Next(3);
}
for (int j = 0; j < edgeCount; j++)
{
graph.CreateEdge(nodes[i], nodes[random.Next(nodes.Length)]);
}
}
// remove all components except the largest one
var adapter = new YGraphAdapter(graph);
NodeList[] components = GraphConnectivity.ConnectedComponents(adapter.YGraph);
Array.Sort(components, (o1, o2) => o2.Count - o1.Count);
for (int i = components.Length - 1; i > 0; i--)
{
foreach (var node in components[i])
{
graph.Remove(adapter.GetOriginalNode(node));
}
}
// add labels
int count = 0;
foreach (var node in graph.Nodes)
{
graph.AddLabel(node, count++.ToString());
}
RandomizeGraph(graph);
}
/// <summary>
/// Called once the move operation has been initialized
/// </summary>
/// <remarks>
/// Calculates which components stay fixed and which nodes will be moved by the user.
/// </remarks>
private void OnMoveInitialized(object sender, EventArgs eventArgs)
{
if (layout != null)
{
CopiedLayoutGraph copy = this.copiedLayoutGraph;
var componentNumber = copy.CreateNodeMap();
GraphConnectivity.ConnectedComponents(copy, componentNumber);
System.Collections.Generic.HashSet <int> movedComponents = new System.Collections.Generic.HashSet <int>();
System.Collections.Generic.HashSet <Node> selectedNodes = new System.Collections.Generic.HashSet <Node>();
foreach (INode node in movedNodes)
{
Node copiedNode = copy.GetCopiedNode(node);
if (copiedNode != null)
{
// remember that we nailed down this node
selectedNodes.Add(copiedNode);
// remember that we are moving this component
movedComponents.Add(componentNumber.GetInt(copiedNode));
//Update the position of the node in the CLG to match the one in the IGraph
layout.SetCenter(copiedNode, node.Layout.X + node.Layout.Width * 0.5, node.Layout.Y + node.Layout.Height * 0.5);
//Actually, the node itself is fixed at the start of a drag gesture
layout.SetInertia(copiedNode, 1.0);
//Increasing has the effect that the layout will consider this node as not completely placed...
// In this case, the node itself is fixed, but it's neighbors will wake up
IncreaseHeat(copiedNode, layout, 0.5);
}
}
// there are components that won't be moved - nail the nodes down so that they don't spread apart infinitely
foreach (var copiedNode in copy.Nodes)
{
if (!movedComponents.Contains(componentNumber.GetInt(copiedNode)))
{
layout.SetInertia(copiedNode, 1);
}
else
{
if (!selectedNodes.Contains(copiedNode))
{
// make it float freely
layout.SetInertia(copiedNode, 0);
}
}
}
// dispose the map
copy.DisposeNodeMap(componentNumber);
//Notify the layout algorithm that there is new work to do...
layout.WakeUp();
}
}
