private async void MyDrawObject_DrawComplete(object sender, DrawEventArgs args)
{
try
{
_myDrawObject.IsEnabled = false;
if (_cts != null)
{
_cts.Cancel();
}
_cts = new CancellationTokenSource();
QueryTask queryTask =
new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/TaxParcel/AssessorsParcelCharacteristics/MapServer/1");
Query query = new Query()
{
Geometry = args.Geometry,
ReturnGeometry = true,
OutSpatialReference = MyMap.SpatialReference
};
QueryResult parcelsToIntersectResult = await queryTask.ExecuteTaskAsync(query, _cts.Token);
List <Graphic> graphicList = new List <Graphic>();
graphicList.Add(new Graphic()
{
Geometry = args.Geometry
});
SimplifyResult simplifiedIntersectGeometryResult = await _geometryService.SimplifyTaskAsync(graphicList, _cts.Token);
IntersectResult intersectedParcelsResult = await _geometryService.IntersectTaskAsync(parcelsToIntersectResult.FeatureSet.ToList(), simplifiedIntersectGeometryResult.Results[0].Geometry, _cts.Token);
Random random = new Random();
foreach (Graphic g in intersectedParcelsResult.Results)
{
SimpleFillSymbol symbol = new SimpleFillSymbol()
{
Fill = new System.Windows.Media.SolidColorBrush(
System.Windows.Media.Color.FromArgb(255, (byte)random.Next(0, 255), (byte)random.Next(0, 255),
(byte)random.Next(0, 255))),
BorderBrush = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Colors.Black),
BorderThickness = 1
};
g.Symbol = symbol;
_intersectGraphicsLayer.Graphics.Add(g);
}
}
catch (Exception ex)
{
if (ex is ServiceException)
{
MessageBox.Show(String.Format("{0}: {1}", (ex as ServiceException).Code.ToString(), (ex as ServiceException).Details[0]), "Error", MessageBoxButton.OK);
return;
}
}
}
// Main simplifying function.
// Should be called asynchronously to show status texts at each step.
public IEnumerable <string> ApplySimplifyingStep()
{
SimplifyResult = SimplifyResult.CannotSimplifyAgain;
List <Graph> newGraphParts = new List <Graph>();
// PREPROCESSING 1: If the graph is not connected, then consider each component separately.
foreach (Graph graphPart in GraphParts)
{
newGraphParts.AddRange(graphPart.SplitDisonnectedComponents());
}
if (newGraphParts.Count > GraphParts.Count)
{
// When no simplification is done in a simplify step, then it can be said
// that the graph can no longer be simplified.
// Here, we did a simplification and we may simplify again in the next step.
SimplifyResult = SimplifyResult.CanSimplifyAgain;
GraphParts = newGraphParts;
}
yield return("PREPROCESS STEP 1: Seperated disconnected components...");
newGraphParts = new List <Graph>();
// PREPROCESSING 2: If the graph has cut-vertices, then test each block separately.
foreach (Graph graphPart in GraphParts)
{
CutVerticesFinder cvf = new CutVerticesFinder();
List <Node> cutNodes = cvf.FindCutVertices(graphPart);
if (cutNodes != null && cutNodes.Count > 1)
{
SimplifyResult = SimplifyResult.CanSimplifyAgain;
// Since we consider "blocks" we need to add back the edges incident to
// cut nodes to get blocks including cut nodes and their edges.
List <Edge> edgesToAddBack = new List <Edge>();
foreach (Node cutNode in cutNodes)
{
List <Edge> edges = graphPart.GetEdges(cutNode);
edgesToAddBack.AddRange(edges);
// Cut nodes AND their edges are removed,
// they will be added back to corresponding blocks.
edges.ForEach(e => graphPart.Edges.Remove(e));
graphPart.Nodes.Remove(cutNode);
}
foreach (Graph disonnectedComponent in graphPart.SplitDisonnectedComponents())
{
// Now we add back the edges.
foreach (Edge edgeToAddBack in edgesToAddBack)
{
Node nodeInComponent = disonnectedComponent.Nodes.FirstOrDefault(n => n == edgeToAddBack.Node1 || n == edgeToAddBack.Node2);
if (nodeInComponent != null)
{
Node cutNode = edgeToAddBack.Node1 == nodeInComponent ? edgeToAddBack.Node2 : edgeToAddBack.Node1;
disonnectedComponent.AddNode(cutNode);
disonnectedComponent.AddEdge(edgeToAddBack);
}
}
newGraphParts.Add(disonnectedComponent);
}
}
else
{
newGraphParts.Add(graphPart);
}
}
GraphParts = newGraphParts;
yield return("PREPROCESS STEP 2: If the graph has cut vertices, seperated all blocks of the graph...");
// PREPROCESSING 3: Each vertex of degree 2 plus its incident edges can be replaced by a single edge.
foreach (Graph graphPart in GraphParts)
{
for (int i = 0; i < graphPart.Nodes.Count; i++)
{
List <Edge> edges = graphPart.GetEdges(graphPart.Nodes[i]);
if (edges.Count == 1)
{
// Node with degree 1 is irrelevant to planarity, we can just remove.
// This step may even be not needed (already removed previously).
graphPart.Edges.Remove(edges[0]);
graphPart.Nodes.Remove(graphPart.Nodes[i]);
i--;
SimplifyResult = SimplifyResult.CanSimplifyAgain;
}
if (edges.Count == 2)
{
// Node with degree 2, delete node and merge edges.
Node node1 = edges[0].Node1 == graphPart.Nodes[i] ? edges[0].Node2 : edges[0].Node1;
Node node2 = edges[1].Node1 == graphPart.Nodes[i] ? edges[1].Node2 : edges[1].Node1;
graphPart.Edges.Remove(edges[0]);
graphPart.Edges.Remove(edges[1]);
graphPart.Nodes.Remove(graphPart.Nodes[i]);
graphPart.GetOrCreateEdge(node1, node2);
i--;
SimplifyResult = SimplifyResult.CanSimplifyAgain;
}
}
}
yield return("PREPROCESS STEP 3: Each vertex of degree 2 plus its incident edges is replaced by a single edge...");
// Remove planar components from "GraphParts" or determine if any of components are non-planar
List <Graph> partsToRemove = new List <Graph>();
foreach (Graph graphPart in GraphParts)
{
int n = graphPart.Nodes.Count;
int e = graphPart.Edges.Count;
if (n < 5 || e < 9)
{
partsToRemove.Add(graphPart);
}
else if (e > 3 * n - 6)
{
PlanarityResult = PlanarityResult.NonPlanar;
}
}
foreach (Graph graph in partsToRemove)
{
GraphParts.Remove(graph);
}
if (GraphParts.Count == 0)
{
PlanarityResult = PlanarityResult.Planar;
}
yield return("PREPROCESS STEP 4: Removed planar components...");
}
