GraphLibrary/DrawGraph/Edge.cs

using System;
using System.Xml.Serialization;

namespace DrawGraph
{
    public class Edge
    {
        [XmlAttribute("source")]
        public Node SourceNode { get; }
        [XmlAttribute("target")]
        public Node TargetNode { get; }
        [XmlAttribute("weight")]
        public int? Weight { get; set; }
        public bool IsFocused { get; }

        public Edge(Node v1, Node v2, bool IsFocused)
        {
            SourceNode = v1;
            TargetNode = v2;
            this.IsFocused = IsFocused;
        }

        public Edge(Node sourceNode, Node targetNode, int weight, bool IsFocused)
        {
            SourceNode = sourceNode;
            TargetNode = targetNode;
            Weight = weight;
            this.IsFocused = IsFocused;
        }

        public static double GetCenterByX(Edge edge)
        {
            var x = (edge.TargetNode.X + edge.SourceNode.X) / 2;
            return x;
        }

        public static double GetCenterByY(Edge edge)
        {
            var y = (edge.TargetNode.Y + edge.SourceNode.Y) / 2;
            return y;
        }

        public static bool IsCursorOnNode(System.Windows.Point cursorPosition, Node Node)
        {
            try
            {
                if (Node.CenterByX - cursorPosition.X <= Settings.NodeWidth / 2 &&
                    Node.CenterByX - cursorPosition.X >= 0)
                {
                    if (Node.CenterByY - cursorPosition.Y <= Settings.NodeHeight / 2 &&
                        Node.CenterByY - cursorPosition.Y >= 0)
                    {
                        return true;
                    }
                }

                if (cursorPosition.X - Node.CenterByX <= Settings.NodeWidth / 2 &&
                    cursorPosition.X - Node.CenterByX >= 0)
                {
                    if (cursorPosition.Y - Node.CenterByY <= Settings.NodeWidth / 2 &&
                        cursorPosition.Y - Node.CenterByY >= 0)
                    {
                        return true;
                    }

                    return false;
                }

                return false;
            }
            catch(Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        public static bool IsNodeBelongToEdge(Edge edge, Node Node)
        {
            if (Node.Compare(Node, edge.SourceNode) || Node.Compare(Node, edge.TargetNode))
                return true;

            return false;
        }
    }
}