Smrf.NodeXL.Visualization.Wpf.EdgeDrawer.TryDrawEdge C# (CSharp) Method

    TryDrawEdge
    (
        IEdge edge,
        GraphDrawingContext graphDrawingContext,
        out EdgeDrawingHistory edgeDrawingHistory
    )
    {
        Debug.Assert(edge != null);
        Debug.Assert(graphDrawingContext != null);
        AssertValid();

        edgeDrawingHistory = null;

        if (graphDrawingContext.GraphRectangleMinusMarginIsEmpty)
        {
            return (false);
        }

        // If the edge is hidden, do nothing.

        VisibilityKeyValue eVisibility = GetVisibility(edge);

        if (eVisibility == VisibilityKeyValue.Hidden)
        {
            return (false);
        }

        DrawingVisual oDrawingVisual = new DrawingVisual();

        using ( DrawingContext oDrawingContext = oDrawingVisual.RenderOpen() )
        {
            Boolean bDrawAsSelected = GetDrawAsSelected(edge);
            Color oColor = GetColor(edge, eVisibility, bDrawAsSelected);
            Double dWidth = GetWidth(edge);
            DashStyle oDashStyle = GetDashStyle(edge, dWidth, bDrawAsSelected);

            Boolean bDrawArrow =
                (m_bDrawArrowOnDirectedEdge && edge.IsDirected);

            IVertex oVertex1 = edge.Vertex1;
            IVertex oVertex2 = edge.Vertex2;

            if (edge.IsSelfLoop)
            {
                if ( !TryDrawSelfLoop(oVertex1, oDrawingContext,
                    graphDrawingContext, oColor, dWidth, bDrawArrow) )
                {
                    // The edge's vertex is hidden, so the edge should be
                    // hidden also.

                    return (false);
                }
            }
            else
            {
                VertexDrawingHistory oVertex1DrawingHistory,
                    oVertex2DrawingHistory;

                Point oEdgeEndpoint1, oEdgeEndpoint2;

                if (
                    !TryGetVertexInformation(oVertex1, oVertex2,
                        out oVertex1DrawingHistory, out oVertex2DrawingHistory,
                        out oEdgeEndpoint1, out oEdgeEndpoint2)
                    ||
                    oEdgeEndpoint1 == oEdgeEndpoint2
                    )
                {
                    // One of the edge's vertices is hidden, so the edge should
                    // be hidden also, or the edge has zero length.

                    return (false);
                }

                Pen oPen = GetPen(oColor, dWidth, oDashStyle);

                Object oLabelAsObject;
                String sLabel = null;

                if ( edge.TryGetValue(ReservedMetadataKeys.PerEdgeLabel,
                    typeof(String), out oLabelAsObject)
                    && oLabelAsObject != null)
                {
                    sLabel = (String)oLabelAsObject;
                }

                if (m_eCurveStyle ==
                    EdgeCurveStyle.CurveThroughIntermediatePoints)
                {
                    DrawCurveThroughIntermediatePoints(
                        edge, graphDrawingContext, oDrawingContext,
                        oVertex1DrawingHistory, oVertex2DrawingHistory,
                        oEdgeEndpoint1, oEdgeEndpoint2, oPen);
                }
                else if (this.ShouldDrawBezierCurve)
                {
                    DrawBezierCurve(
                        edge, graphDrawingContext, oDrawingContext,
                        oEdgeEndpoint1, oEdgeEndpoint2, bDrawAsSelected,
                        bDrawArrow, oPen, oColor, dWidth, eVisibility, sLabel);
                }
                else
                {
                    DrawStraightEdge(
                        edge, graphDrawingContext, oDrawingContext,
                        oEdgeEndpoint1, oEdgeEndpoint2, bDrawAsSelected,
                        bDrawArrow, oPen, oColor, dWidth, eVisibility, sLabel);
                }
            }

            // Retain information about the edge that was drawn.

            edgeDrawingHistory = new EdgeDrawingHistory(
                edge, oDrawingVisual, bDrawAsSelected, dWidth);

            return (true);
        }
    }