GetEdgeDrawingVisuals
(
EdgeDrawingHistory oEdgeDrawingHistory
)
{
Debug.Assert(oEdgeDrawingHistory != null);
AssertValid();
return(oEdgeDrawingHistory.DrawnAsSelected ?
m_oSelectedEdgeDrawingVisuals : m_oUnselectedEdgeDrawingVisuals);
}
//*************************************************************************
// Method: GetEdgeDrawingVisuals()
//
/// <summary>
/// Gets a DrawingVisual that contains all the visuals for either
/// unselected edges or selected edges.
/// </summary>
///
/// <param name="oEdgeDrawingHistory">
/// Determines which DrawingVisual gets returned.
/// </param>
///
/// <returns>
/// If <paramref name="oEdgeDrawingHistory" /> indicates that the edge was
/// drawn as unselected, then the DrawingVisual that contains all the
/// visuals for unselected edges is returned. Otherwise, the DrawingVisual
/// that contains all the visuals for selected edges is returned.
/// </returns>
//*************************************************************************
protected DrawingVisual GetEdgeDrawingVisuals(
EdgeDrawingHistory oEdgeDrawingHistory
)
{
Debug.Assert(oEdgeDrawingHistory != null);
AssertValid();
return (oEdgeDrawingHistory.DrawnAsSelected ?
m_oSelectedEdgeDrawingVisuals : m_oUnselectedEdgeDrawingVisuals);
}
TryDrawEdge
(
IEdge edge,
GraphDrawingContext graphDrawingContext,
out EdgeDrawingHistory edgeDrawingHistory
)
{
Debug.Assert(edge != null);
Debug.Assert(graphDrawingContext != null);
AssertValid();
edgeDrawingHistory = null;
// If the edge is hidden, do nothing.
VisibilityKeyValue eVisibility = GetVisibility(edge);
if (eVisibility == VisibilityKeyValue.Hidden)
{
return(false);
}
Boolean bDrawAsSelected = GetDrawAsSelected(edge);
Color oColor = GetColor(edge, eVisibility, bDrawAsSelected);
Double dWidth = GetWidth(edge, bDrawAsSelected);
DashStyle oDashStyle = GetDashStyle(edge, dWidth, bDrawAsSelected);
Boolean bDrawArrow = (m_bDrawArrowOnDirectedEdge && edge.IsDirected);
IVertex [] aoVertices = edge.Vertices;
DrawingVisual oDrawingVisual = new DrawingVisual();
using (DrawingContext oDrawingContext = oDrawingVisual.RenderOpen())
{
if (edge.IsSelfLoop)
{
if (!TryDrawSelfLoop(aoVertices[0], oDrawingContext,
graphDrawingContext, oColor, dWidth, bDrawArrow))
{
// The edge's vertex is hidden, so the edge should be
// hidden also.
return(false);
}
}
else
{
Point oEdgeEndpoint1, oEdgeEndpoint2;
if (!TryGetEdgeEndpoints(aoVertices[0], aoVertices[1],
graphDrawingContext, out oEdgeEndpoint1,
out oEdgeEndpoint2))
{
// One of the edge's vertices is hidden, so the edge should
// be hidden also.
return(false);
}
if (bDrawArrow)
{
// Draw the arrow and set the second endpoint to the center
// of the flat end of the arrow.
Double dArrowAngle = WpfGraphicsUtil.GetAngleBetweenPoints(
oEdgeEndpoint1, oEdgeEndpoint2);
oEdgeEndpoint2 = DrawArrow(oDrawingContext, oEdgeEndpoint2,
dArrowAngle, oColor, dWidth);
}
// Draw the edge.
oDrawingContext.DrawLine(GetPen(oColor, dWidth, oDashStyle),
oEdgeEndpoint1, oEdgeEndpoint2);
// Draw the edge's label, if there is one.
Object oLabelAsObject;
if (edge.TryGetValue(ReservedMetadataKeys.PerEdgeLabel,
typeof(String), out oLabelAsObject) &&
oLabelAsObject != null)
{
DrawLabel(oDrawingContext, graphDrawingContext,
oEdgeEndpoint1, oEdgeEndpoint2,
(String)oLabelAsObject, oColor);
}
}
// Retain information about the edge that was drawn.
edgeDrawingHistory = new EdgeDrawingHistory(
edge, oDrawingVisual, bDrawAsSelected);
return(true);
}
}
