private void CollapseExpandButton_Click(object sender, RoutedEventArgs e)
{
// the Button is in the visual tree of a Node
Button button = (Button)sender;
Group sg = Part.FindAncestor <Group>(button);
if (sg != null)
{
SimpleData subgraphdata = (SimpleData)sg.Data;
if (!subgraphdata.IsSubGraph)
{
return;
}
// always make changes within a transaction
myDiagram.StartTransaction("CollapseExpand");
// if needed, create the child data for this node
if (!subgraphdata.EverExpanded && !sg.IsExpandedSubGraph)
{
subgraphdata.EverExpanded = true; // only create children once per node
int nummembers = CreateSubGraph(subgraphdata);
if (nummembers == 0) // now known no children: don't need Button
{
button.Visibility = Visibility.Collapsed;
}
}
// toggle whether this node is expanded or collapsed
sg.IsExpandedSubGraph = !sg.IsExpandedSubGraph;
myDiagram.Panel.CenterPart(sg);
myDiagram.CommitTransaction("CollapseExpand");
}
}
// Create some member nodes, including nested subgraphs, for PARENTDATA.
// PARENTDATA may be null when creating the initial, top-level nodes
private int CreateSubGraph(SimpleData group)
{
ISubGraphModel sgmodel = myDiagram.Model as ISubGraphModel;
if (sgmodel == null)
{
return(0);
}
myDiagram.StartTransaction("Add Group contents");
var nodes = new List <SimpleData>(); // this will contain all of the member nodes created
int groupCount = myDiagram.Nodes.OfType <Group>().Count();
// create a random number of subgraphs
// ensure there are at least 10 groups in the diagram
var numgroups = rand.Next(2);
if (groupCount < 10)
{
numgroups += 1;
}
for (int i = 0; i < numgroups; i++)
{
var g = new SimpleData();
g.Color = String.Format("#{0:X}{1:X}{2:X}", 80 + rand.Next(100), 80 + rand.Next(100), 80 + rand.Next(100));
g.Key = "group" + (i + groupCount).ToString();
g.IsSubGraph = true;
if (group != null)
{
g.SubGraphKey = group.Key; // declare that it's a member of nodedata
}
sgmodel.AddNode(g);
nodes.Add(g);
}
var numnodes = rand.Next(4) + 2;
// create a random number of non-group nodes
for (int i = 0; i < numnodes; i++)
{
var n = new SimpleData();
n.Color = String.Format("#{0:X}{1:X}{2:X}", 80 + rand.Next(100), 80 + rand.Next(100), 80 + rand.Next(100));
n.Key = n.Color;
if (group != null)
{
n.SubGraphKey = group.Key; // declare that it's a member of nodedata
}
sgmodel.AddNode(n);
nodes.Add(n);
}
// add at least one link from each node to another
// this could result in clusters of nodes unreachable from each other, but no lone nodes
nodes.Sort((x, y) => x.Color.CompareTo(y.Color));
for (int i = 0; i < nodes.Count; i++)
{
var d = nodes[i];
int from = rand.Next(nodes.Count - i) + i;
if (from != i)
{
d.FromKeys.Add(nodes[from].Key);
}
}
myDiagram.CommitTransaction("Add Group contents");
return(nodes.Count);
}