GleeCurveToPointFArray
(
Microsoft.Glee.Splines.Curve oCurve
)
{
Debug.Assert(oCurve != null);
AssertValid();
// This is based on code in Microsoft.Glee.GraphViewerGdi.GViewer.
// TransferGeometryFromGleeGraphToGraph() in the GLEE source code,
System.Collections.Generic.List<PointF> oPointFList =
new System.Collections.Generic.List<PointF>();
Microsoft.Glee.Splines.Point oGleePoint =
(oCurve.Segs[0] as Microsoft.Glee.Splines.CubicBezierSeg).B(0);
oPointFList.Add( GleePointToPointF(oGleePoint) );
foreach (Microsoft.Glee.Splines.CubicBezierSeg oCubicBezierSeg in
oCurve.Segs)
{
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(1) ) );
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(2) ) );
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(3) ) );
}
return ( oPointFList.ToArray() );
}
GleeCurveToTransformedPointFArray
(
Microsoft.Glee.Splines.Curve oCurve,
Matrix oTransformationMatrix
)
{
Debug.Assert(oCurve != null);
Debug.Assert(oTransformationMatrix != null);
AssertValid();
// Load the curve points into a list.
System.Collections.Generic.List<PointF> oPointFList =
new System.Collections.Generic.List<PointF>();
Microsoft.Glee.Splines.Point oGleePoint =
(oCurve.Segs[0] as Microsoft.Glee.Splines.CubicBezierSeg).B(0);
oPointFList.Add( GleePointToPointF(oGleePoint) );
foreach (Microsoft.Glee.Splines.CubicBezierSeg oCubicBezierSeg in
oCurve.Segs)
{
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(1) ) );
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(2) ) );
oPointFList.Add( GleePointToPointF(oCubicBezierSeg.B(3) ) );
}
// Convert the list to an array and transform it to NodeXL coordinates.
PointF [] aoCurvePoints = oPointFList.ToArray();
oTransformationMatrix.TransformPoints(aoCurvePoints);
return (aoCurvePoints);
}
LayOutGraphCore
(
IGraph graph,
ICollection<IVertex> verticesToLayOut,
LayoutContext layoutContext,
BackgroundWorker backgroundWorker
)
{
Debug.Assert(graph != null);
Debug.Assert(verticesToLayOut != null);
Debug.Assert(verticesToLayOut.Count > 0);
Debug.Assert(layoutContext != null);
AssertValid();
// This class does not incorporate GLEE source code to implement the
// layout. Instead, it transfers the NodeXL graph to a GLEE graph,
// tells GLEE to lay out the GLEE graph, then reads the resulting
// layout geometry from the GLEE graph and stores it as metadata in the
// NodeXL graph. Although this involves several copy operations, it
// uses only the GLEE public interfaces and bypasses all the
// maintenance headaches that would arise if the GLEE source code were
// used.
//
// Note:
//
// This class was written when the NodeXL visualization layer used
// GDI+. There were complex families of vertex and edge drawers,
// including SugiyamaVertexDrawer and EdgeVertexDrawer. This class
// stores vertex and edge metadata meant for use by those
// Sugiyama-specific drawers, which were eliminated when the
// visualization layer was changed to WPF and the vertex- and edge-
// drawing code was vastly simplified. Therefore, the vertex radius
// and edge curve information stored by this class is currently ignored
// in the WPF layer. Vertices are of constant size, and edges are
// drawn as straight lines.
//
// This could be fixed by modifying the WPF layer to be Sugiyama-aware,
// but as of June 2009 no one has complained about these problems and
// so the fix is postponed.
// Create a GLEE graph.
Microsoft.Glee.GleeGraph oGleeGraph = new Microsoft.Glee.GleeGraph();
// Get the vertex radius specified by the SugiyamaVertexDrawer.
Single fNodeXLVertexRadius = GetNodeXLVertexRadius(layoutContext);
// Loop through the NodeXL vertices.
foreach (IVertex oVertex in verticesToLayOut)
{
// Create a circle that defines the GLEE node's boundary. GLEE's
// layout code does not modify the node's boundary, it just shifts
// the node's center.
Microsoft.Glee.Splines.ICurve oCurve =
Microsoft.Glee.Splines.CurveFactory.CreateEllipse(
fNodeXLVertexRadius, fNodeXLVertexRadius,
new Microsoft.Glee.Splines.Point(0, 0)
);
// Create a GLEE node that corresponds to the NodeXL node.
Microsoft.Glee.Node oGleeNode =
new Microsoft.Glee.Node(oVertex.ID.ToString(), oCurve);
oGleeGraph.AddNode(oGleeNode);
// Store the GLEE node as temporary metadata in the NodeXL node.
oVertex.SetValue(ReservedMetadataKeys.SugiyamaGleeNode, oGleeNode);
}
// Loop through the NodeXL edges.
ICollection<IEdge> oEdgesToLayOut =
GetEdgesToLayOut(graph, verticesToLayOut);
foreach (IEdge oEdge in oEdgesToLayOut)
{
// Retrieve the NodeXL edge's vertices.
IVertex [] aoVertices = oEdge.Vertices;
// Retrieve the corresponding GLEE node for the NodeXL edge's
// vertices.
Microsoft.Glee.Node oGleeNode0 =
NodeXLVertexToGleeNode( aoVertices[0] );
Microsoft.Glee.Node oGleeNode1 =
NodeXLVertexToGleeNode( aoVertices[1] );
// Create a GLEE edge using the two GLEE nodes.
Microsoft.Glee.Edge oGleeEdge =
new Microsoft.Glee.Edge(oGleeNode0, oGleeNode1);
oGleeGraph.AddEdge(oGleeEdge);
// Store the GLEE edge as temporary metadata in the NodeXL edge.
oEdge.SetValue(
ReservedMetadataKeys.SugiyamaGleeEdge, oGleeEdge);
}
// Tell GLEE to lay out the GLEE graph. This shifts the node centers,
// connects the nodes with lines, and computes the smallest rectangle
// that contains all the nodes and edges.
oGleeGraph.CalculateLayout();
// The rectangle computed by GLEE does not have the dimensions
// specified by layoutContext.GraphRectangle. Get a transformation
// that will map coordinates in the GLEE rectangle to coordinates in
// the specified NodeXL rectangle.
Matrix oTransformationMatrix =
GetTransformationMatrix(oGleeGraph, layoutContext.GraphRectangle);
// Because of the transformation, the radius of the vertices is no
// longer the original fNodeXLVertexRadius. Compute the transformed
// radius.
PointF [] aoRadiusPoints = new PointF [] {
PointF.Empty,
new PointF(0, fNodeXLVertexRadius)
};
oTransformationMatrix.TransformPoints(aoRadiusPoints);
Double dX = aoRadiusPoints[1].X - aoRadiusPoints[0].X;
Double dY = aoRadiusPoints[1].Y - aoRadiusPoints[0].Y;
Single fTransformedNodeXLVertexRadius =
(Single)Math.Sqrt(dX * dX + dY * dY);
// Store the computed radius as metadata on the graph, to be retrieved
// by SugiyamaVertexDrawer.DrawVertex().
graph.SetValue(ReservedMetadataKeys.SugiyamaComputedRadius,
fTransformedNodeXLVertexRadius);
// Loop through the NodeXL vertices again.
foreach (IVertex oVertex in verticesToLayOut)
{
// Retrieve the corresponding GLEE node.
Microsoft.Glee.Node oGleeNode =
NodeXLVertexToGleeNode(oVertex);
oVertex.RemoveKey(ReservedMetadataKeys.SugiyamaGleeNode);
// Get the shifted node center and transform it to NodeXL
// coordinates.
if ( !VertexIsLocked(oVertex) )
{
oVertex.Location = GleePointToTransformedPointF(
oGleeNode.Center, oTransformationMatrix);
}
}
// Loop through the NodeXL edges again.
foreach (IEdge oEdge in oEdgesToLayOut)
{
// Retrieve the corresponding GLEE edge.
Microsoft.Glee.Edge oGleeEdge = NodeXLEdgeToGleeEdge(oEdge);
oEdge.RemoveKey(ReservedMetadataKeys.SugiyamaGleeEdge);
// Get the GLEE curve that describes most (but not all) of the
// edge.
Microsoft.Glee.Splines.Curve oCurve =
(Microsoft.Glee.Splines.Curve)oGleeEdge.Curve;
// TODO: In Microsoft.Glee.GraphViewerGdi.GViewer.
// TransferGeometryFromGleeGraphToGraph() in the GLEE source code,
// oCurve can apparently be null. Can it be null here? For now,
// assume that the answer is no.
Debug.Assert(oCurve != null);
// Convert the curve to an array of PointF objects in NodeXL
// coordinates.
PointF [] aoCurvePoints = GleeCurveToTransformedPointFArray(
oCurve, oTransformationMatrix);
// Store the array as metadata in the edge, to be retrieved by
// SugiyamaEdgeDrawer.DrawEdge().
oEdge.SetValue(
ReservedMetadataKeys.SugiyamaCurvePoints, aoCurvePoints);
// Get the endpoint of the curve and transform it to NodeXL
// coordinates.
PointF oEndpoint = GleePointToTransformedPointF(
oGleeEdge.ArrowHeadAtTargetPosition, oTransformationMatrix);
// Store the endpoint as metadata in the edge, to be retrieved by
// SugiyamaEdgeDrawer.DrawEdge().
oEdge.SetValue(ReservedMetadataKeys.SugiyamaEndpoint, oEndpoint);
}
return (true);
}