Hi,

GetNearestNode takes a Point parameter, to which you pass first argument of your AlignToNearestPoint method. I suppose that corresponds to current mouse position, if you haven't modified it earlier to match a snap point on your nodes. Also check if Diagram.AlignToGrid is enabled, then you might be passing a grid point to GetNearestNode instead of the mouse position and getting unexpected results.

As for prioritizing nodes, instead of GetNearestNode try calling GetNodesInViewport method, and then sorting the returned list by your priorities.

I hope that helps,
Stoyan

Hi Stoyan,

We have operator nodes (with the left and right slot) which should be able to nest in each other. Initially we use diagram.GetNearestNode() for all nodes. But in the case of the operator that method always returns the outer parent which makes nesting into one of the children difficult. For operators we use our own method GetClosestNode() which utilizes diagram.GetNodesInViewPort() and then returns a node based on our criteria. So far we have:

public override DiagramNode GetClosestNode()
        {
            Point sourcePoint = Bounds.TopLeft;
            DiagramNodeCollection allNodes = Parent.GetNodesInViewport();
            DiagramNode closestNode = allNodes.FirstOrDefault(x => ((new Point(x.Bounds.Left + x.Bounds.Width / 2, x.Bounds.Bottom) - sourcePoint).Length <= snapRange + 10));
            //DiagramNode closestNode = allNodes.FirstOrDefault(x => (x.GetCenter() - sourcePoint).Length <= snapRange + 10);

            if (closestNode is BROperatorNode)
            {
                List<DiagramNode> availableOperators = allNodes.ToList();
                availableOperators.RemoveAll(x => ((BRNode)x).NodeType != BRNodeType.OPERATOR);
                availableOperators.Remove(this);
                BRNode leftCopy = leftConnectedNode;
                BRNode rightCopy = rightConnectedNode;
                while (leftCopy != null)
                {
                    availableOperators.Remove(leftCopy);
                    if (leftCopy is BROperatorNode)
                    {
                        leftCopy = ((BROperatorNode)leftCopy).leftConnectedNode;
                    }
                    else
                        break;
                }
                while (rightCopy != null)
                {
                    availableOperators.Remove(rightCopy);
                    if (rightCopy is BROperatorNode)
                    {
                        rightCopy = ((BROperatorNode)rightCopy).leftConnectedNode;
                    }
                    else
                        break;
                }
                closestNode = availableOperators.FirstOrDefault(x => ((((BROperatorNode)x).txtPosWithDiagramCoordinates - sourcePoint).Length <= snapRange + 10));
            }
            return closestNode;
        }
 

The operator itself should be able to nest but also align to other nodes which is why we use allNodes.FirstOrDefault(<predicate>). Now we're having difficulties giving a concise predicate for both operators and other nodes. We tried using GetCenter() for x but the center coordinate sometimes conflicts with where the slot is (see image below).



As seen in the code of our method we now use: x => ((new Point(x.Bounds.Left + x.Bounds.Width / 2, x.Bounds.Bottom) - sourcePoint).Length

This, however, does not work when an operator is dragged towards the operator slot in the node which can be seen in image below. Now we have to drop an operator near the bottom of that node for it to align to the operator slot.



How can we make sure the method searches for the correct child in an operator and at the same time for a regular node?

We would appreciate any ideas

Greets,

Vincent

Yes, we were slightly hoping there would be a easy way to do it without adding such a class. But it works perfectly nonetheless! 

Thanks for the input 

Greets,

Vincent