Hi,

This can be done only by overriding the link's UpdateVisuals method. For example this implements something like the "Distant-Hostile" link:

public class MyLink : DiagramLink
{
	public MyLink() {}

	public MyLink(Diagram diagram) : base(diagram)
	{
	}

	protected override void UpdateVisuals()
	{
		base.UpdateVisuals();

		var canvas = Content as Canvas;
		if (canvas != null)
		{
			if (!canvas.Children.Contains(myPath))
				canvas.Children.Add(myPath);
			UpdatePath();
		}
	}

	private void UpdatePath()
	{
		var b = GetBounds();
		var p0 = ControlPoints[0];
		p0.X -= b.X; p0.Y -= b.Y;
		var p1 = ControlPoints[ControlPoints.Count - 1];
		p1.X -= b.X; p1.Y -= b.Y;

		double dx = p1.X - p0.X;
		double dy = p1.Y - p0.Y;

		var g = new PathGeometry();
		var f = new PathFigure
		{
			IsClosed = false,
			IsFilled = false,
			StartPoint = p0
		};

		double a = 0, r = 0, s = -1;
		CartesianToPolar(p0, p1, ref a, ref r);

		for (int i = 1; i < 10; ++i )
		{
			Point fp = p0;
			fp.X += i * dx / 10;
			fp.Y += i * dy / 10;
			PolarToCartesian(fp, a + s * 90, 20, ref fp);
			s *= -1;
			f.Segments.Add(new LineSegment { Point = fp });
		}

		g.Figures.Add(f);
		myPath.Data = g;
		myPath.Stroke = Brushes.Red;
	}

	static void PolarToCartesian(Point coordCenter, double a, double r, ref Point cartesian)
	{
		if (r == 0)
		{
			cartesian = coordCenter;
			return;
		}
		cartesian.X = coordCenter.X + Math.Cos(a * Math.PI / 180) * r;
		cartesian.Y = coordCenter.Y - Math.Sin(a * Math.PI / 180) * r;
	}

	static void CartesianToPolar(Point coordCenter, Point cartesian, ref double a, ref double r)
	{
		if (coordCenter == cartesian)
		{
			a = 0;
			r = 0;
			return;
		}
		double dx = cartesian.X - coordCenter.X;
		double dy = cartesian.Y - coordCenter.Y;
		r = Math.Sqrt(Math.Pow(dx, 2) + Math.Pow(dy, 2));
		a = Math.Atan(-dy / dx) * 180 / Math.PI;
		if (dx < 0) a += 180;
	}

	private readonly Path myPath = new Path();
} 

You can let users draw that kind of links through a custom Behavior class:

public class MyBehavior : LinkShapesBehavior
{
	public MyBehavior(Diagram diagram)
		: base(diagram)
	{
	}

	protected override DiagramLink CreateLink(DiagramNode origin, Point point)
	{
		var link = new MyLink(Diagram);
		link.Origin = origin;
		return link;
	}
} 

I hope that helps,
Stoyan

Hi Stoyo

Is it possible to add some small button for each line segment (when the line is horizontal and vertical only) and some handler for that button with which user can move the line vertically up/down or horizontally left/right.


-Rajesh

Hi Stoyo

Ya. For each segement i want to add the button centrally on that segment and movement of that should be either vertical or horizontal.

The behavior expected in my post "Line Position Changer"
http://mindfusion.eu/Forum/YaBB.pl?board=diaglite_disc;action=display;num=126638...

The sample link provided over there doesn't do as expected. Can you provide a sample for same.
Not necessary it should be button. It can be path which looks like button and handler/attachment of mouse events for those paths.

Or, in other words, sample for changing the intermediate shape with custom paths gemoetry.

-Rajesh

Hi Stoyo

With code provided I did following thing.
I have two nodes horizontally placed and established a line between them with start and end points only.

Now dragging start and end point tries to move there position as expected. If i click some where in between the link and moves the mouse, two new points gets inserted and I can move those points horizontally.

This is not what I expect.

My expectation is as below -
I have two nodes horizonally placed and there is a link between these two points.

The points are linked vertically center at left and right edges of the nodes.
If I assume the link is between (100,50) and (300,50) points their central location is (150,50).

At this particular point ( 150,50) i need some small button which i can move vertically up or down to make the lines start end points either
1. (100,45) and (300,45) or
2. (100,40) and (300,40) or
3. (100,53) and (300, 53) etc.

And the center point for the line where the button will be shown will either
(150,45) or  (150,40) or (150,53).


I hope the requiement is clear now.

-Regards
Rajesh