//*************************************************************************
// Method: LayOutGraphCore()
//
/// <summary>
/// Lays out a graph synchronously or asynchronously.
/// </summary>
///
/// <param name="graph">
/// Graph to lay out. The graph is guaranteed to have at least one vertex.
/// </param>
///
/// <param name="verticesToLayOut">
/// Vertices to lay out. The collection is guaranteed to have at least one
/// vertex.
/// </param>
///
/// <param name="layoutContext">
/// Provides access to objects needed to lay out the graph. The <see
/// cref="LayoutContext.GraphRectangle" /> is guaranteed to have non-zero
/// width and height.
/// </param>
///
/// <param name="backgroundWorker">
/// <see cref="BackgroundWorker" /> whose worker thread called this method
/// if the graph is being laid out asynchronously, or null if the graph is
/// being laid out synchronously.
/// </param>
///
/// <returns>
/// true if the layout was successfully completed, false if the layout was
/// cancelled. The layout can be cancelled only if the graph is being laid
/// out asynchronously.
/// </returns>
///
/// <remarks>
/// This method lays out the graph <paramref name="graph" /> either
/// synchronously (if <paramref name="backgroundWorker" /> is null) or
/// asynchronously (if (<paramref name="backgroundWorker" /> is not null)
/// by setting the the <see cref="IVertex.Location" /> property on the
/// vertices in <paramref name="verticesToLayOut" /> and optionally adding
/// geometry metadata to the graph, vertices, or edges.
///
/// <para>
/// In the asynchronous case, the <see
/// cref="BackgroundWorker.CancellationPending" /> property on the
/// <paramref name="backgroundWorker" /> object should be checked before
/// each layout iteration. If it's true, the method should immediately
/// return false. Also, <see
/// cref="AsyncLayoutBase.FireLayOutGraphIterationCompleted()" /> should be
/// called after each iteration.
/// </para>
///
/// <para>
/// The arguments have already been checked for validity.
/// </para>
///
/// </remarks>
//*************************************************************************
protected override Boolean 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();
if (backgroundWorker != null && backgroundWorker.CancellationPending)
{
return (false);
}
ICollection<IEdge> oEdgesToLayOut =
GetEdgesToLayOut(graph, verticesToLayOut);
Int32 iVertices = verticesToLayOut.Count;
// The MultiScaleLayout class uses a simple scheme where the graph's
// vertices consist of the integers 0 through N-1, where N is the
// number of vertices in the graph. NodeXL uses IVertex objects and
// the vertex collection isn't indexed. Work around this
// incompatibility by creating a dictionary that maps vertices to
// zero-based vertex indexes.
Dictionary<IVertex, Int32> oVertexDictionary =
new Dictionary<IVertex, Int32>(iVertices);
Int32 iVertexIndex = 0;
foreach (IVertex oVertex in verticesToLayOut)
{
oVertexDictionary.Add(oVertex, iVertexIndex);
iVertexIndex++;
}
// Create and populate a MultiScaleLayout graph.
MultiScaleLayout.Graph oMultiScaleLayoutGraph =
new MultiScaleLayout.Graph(iVertices, String.Empty);
foreach (IEdge oEdge in oEdgesToLayOut)
{
IVertex [] aoEdgeVertices = oEdge.Vertices;
oMultiScaleLayoutGraph.AddEdge(
oVertexDictionary[ aoEdgeVertices[0] ],
oVertexDictionary[ aoEdgeVertices[1] ]
);
}
// Lay it out.
oMultiScaleLayoutGraph.PrepareForUse();
MultiScaleLayout.GraphLayoutSettings oGraphLayoutSettings =
new MultiScaleLayout.GraphLayoutSettings(m_iRad,
m_iLocalIterations, m_iRatio, m_iMinSize);
oMultiScaleLayoutGraph.MultiScaleLayout(
( new Random() ).Next(), oGraphLayoutSettings);
// Retrieve the laid out vertex coordinates, which are normalized to
// fall within the range [0,1].
MultiScaleLayout.PointD [] oMultiScaleLayoutLocations =
oMultiScaleLayoutGraph.vertexCoords;
Rectangle oRectangle = layoutContext.GraphRectangle;
Debug.Assert(oRectangle.Width > 0);
Debug.Assert(oRectangle.Height > 0);
Int32 iLeft = oRectangle.Left;
Int32 iTop = oRectangle.Top;
Int32 iWidth = oRectangle.Width;
Int32 iHeight = oRectangle.Height;
foreach (IVertex oVertex in verticesToLayOut)
{
if ( !VertexIsLocked(oVertex) )
{
// Convert the normalized coordinates to coordinates within the
// layout rectangle.
MultiScaleLayout.PointD oMultiScaleLayoutLocation =
oMultiScaleLayoutLocations[ oVertexDictionary[oVertex] ];
oVertex.Location = new PointF(
iLeft + (Single)(oMultiScaleLayoutLocation.x * iWidth),
iTop + (Single)(oMultiScaleLayoutLocation.y * iHeight)
);
}
}
return (true);
}
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();
if (backgroundWorker != null && backgroundWorker.CancellationPending)
{
return(false);
}
ICollection <IEdge> oEdgesToLayOut =
GetEdgesToLayOut(graph, verticesToLayOut);
Int32 iVertices = verticesToLayOut.Count;
// The MultiScaleLayout class uses a simple scheme where the graph's
// vertices consist of the integers 0 through N-1, where N is the
// number of vertices in the graph. NodeXL uses IVertex objects and
// the vertex collection isn't indexed. Work around this
// incompatibility by creating a dictionary that maps vertices to
// zero-based vertex indexes.
Dictionary <IVertex, Int32> oVertexDictionary =
new Dictionary <IVertex, Int32>(iVertices);
Int32 iVertexIndex = 0;
foreach (IVertex oVertex in verticesToLayOut)
{
oVertexDictionary.Add(oVertex, iVertexIndex);
iVertexIndex++;
}
// Create and populate a MultiScaleLayout graph.
MultiScaleLayout.Graph oMultiScaleLayoutGraph =
new MultiScaleLayout.Graph(iVertices, String.Empty);
foreach (IEdge oEdge in oEdgesToLayOut)
{
IVertex [] aoEdgeVertices = oEdge.Vertices;
oMultiScaleLayoutGraph.AddEdge(
oVertexDictionary[aoEdgeVertices[0]],
oVertexDictionary[aoEdgeVertices[1]]
);
}
// Lay it out.
oMultiScaleLayoutGraph.PrepareForUse();
MultiScaleLayout.GraphLayoutSettings oGraphLayoutSettings =
new MultiScaleLayout.GraphLayoutSettings(m_iRad,
m_iLocalIterations, m_iRatio, m_iMinSize);
oMultiScaleLayoutGraph.MultiScaleLayout(
(new Random()).Next(), oGraphLayoutSettings);
// Retrieve the laid out vertex coordinates, which are normalized to
// fall within the range [0,1].
MultiScaleLayout.PointD [] oMultiScaleLayoutLocations =
oMultiScaleLayoutGraph.vertexCoords;
Rectangle oRectangle = layoutContext.GraphRectangle;
Debug.Assert(oRectangle.Width > 0);
Debug.Assert(oRectangle.Height > 0);
Int32 iLeft = oRectangle.Left;
Int32 iTop = oRectangle.Top;
Int32 iWidth = oRectangle.Width;
Int32 iHeight = oRectangle.Height;
foreach (IVertex oVertex in verticesToLayOut)
{
if (!VertexIsLocked(oVertex))
{
// Convert the normalized coordinates to coordinates within the
// layout rectangle.
MultiScaleLayout.PointD oMultiScaleLayoutLocation =
oMultiScaleLayoutLocations[oVertexDictionary[oVertex]];
oVertex.Location = new PointF(
iLeft + (Single)(oMultiScaleLayoutLocation.x * iWidth),
iTop + (Single)(oMultiScaleLayoutLocation.y * iHeight)
);
}
}
return(true);
}
