Question Experimental graphView : Cannot open SearchWindow when Edge dropped outside a Port

Hey there, I'm working on a Dialogue Node System using Unity's experimental GraphView library and I've created a simple SearchWindow to instantiate custom Nodes and Groups when the space key or right click is pressed. I would like to know if it was possible to open the SearchWindow when the user drops an Edge outside a Port, just like in Unity's Shader Graph ?

I know the GraphView has some callbacks to automate some simple commands like that, that's how I used the callback "nodeCreationRequest" to open the window with a single click, but are there callbacks for edges ? If so, how to override them ? I've seen the EdgeConnector class has some callbacks from an interface but they're inaccessible.

Thank you for your help.

 

@Quasar47 Where you ever able to solve this problem? I want to implement the same thing and am stuck at the exact same place as you were. Any hints would help.

 

Hello,
Unfortunately, no. I eventually had to ship my tool, and so I had to drop the issue after a few tries.
Sorry for now being able to be helpful. If you ever find a workaround to this problem, feel free to post it here so that others don't have to lookup for themselves.

 

I figured this out.

So the movable ghost edge does not exist in

GraphView

, but exists in the

Node > Port

side.

Port 

has overridable methods called

OnStartEdgeDragging()

and

OnStopEdgeDragging()

.

What you need to do is create a

PortView

class that inherits from

Port

and create the

DefaultEdgeConnectorListener

private class' equivalent.

Code (CSharp):

1.  
2. namespace TG.Frameworks.NodeTrees.Editor
3. {
4.     public class PortView : Port
5.     {
6.         protected PortView(Orientation portOrientation, Direction portDirection, Capacity portCapacity, Type type) : base(portOrientation, portDirection, portCapacity, type)
7.         {
8.      
9.         }
10.  
11.         public override void OnStartEdgeDragging()
12.         {
13.             base.OnStartEdgeDragging();
14.             Debug.Log("Dragging");
15.         }
16.  
17.         public override void OnStopEdgeDragging()
18.         {
19.             base.OnStopEdgeDragging();
20.             Debug.Log("Stopped Dragging");
21.         }
22.  
23.         public new static Port Create<TEdge>(
24.             Orientation orientation,
25.             Direction direction,
26.             Capacity capacity,
27.             Type type)
28.             where TEdge : Edge, new()
29.         {
30.             DefaultEdgeConnectorListener listener = new DefaultEdgeConnectorListener();
31.             PortView ele = new PortView(orientation, direction, capacity, type)
32.             {
33.                 m_EdgeConnector = new EdgeConnector<TEdge>(listener)
34.             };
35.             ele.AddManipulator(ele.m_EdgeConnector);
36.             return ele;
37.         }
38.  
39.         private class DefaultEdgeConnectorListener : IEdgeConnectorListener
40.         {
41.             private GraphViewChange _graphViewChange;
42.             private List<Edge> _edgesToCreate;
43.             private List<GraphElement> _edgesToDelete;
44.  
45.             public DefaultEdgeConnectorListener()
46.             {
47.                 _edgesToCreate = new List<Edge>();
48.                 _edgesToDelete = new List<GraphElement>();
49.                 _graphViewChange.edgesToCreate = _edgesToCreate;
50.             }
51.  
52.             public void OnDropOutsidePort(Edge edge, Vector2 position)
53.             {
54.             }
55.  
56.             public void OnDrop(GraphView graphView, Edge edge)
57.             {
58.                 _edgesToCreate.Clear();
59.                 _edgesToCreate.Add(edge);
60.                 _edgesToDelete.Clear();
61.                 if (edge.input.capacity == Capacity.Single)
62.                 {
63.                     foreach (Edge connection in edge.input.connections)
64.                     {
65.                         if (connection != edge)
66.                             _edgesToDelete.Add(connection);
67.                     }
68.                 }
69.  
70.                 if (edge.output.capacity == Capacity.Single)
71.                 {
72.                     foreach (Edge connection in edge.output.connections)
73.                     {
74.                         if (connection != edge)
75.                             _edgesToDelete.Add(connection);
76.                     }
77.                 }
78.  
79.                 if (_edgesToDelete.Count > 0)
80.                     graphView.DeleteElements(_edgesToDelete);
81.                 List<Edge> edgesToCreate = _edgesToCreate;
82.                 if (graphView.graphViewChanged != null)
83.                     edgesToCreate = graphView.graphViewChanged(_graphViewChange).edgesToCreate;
84.                 foreach (Edge edge1 in edgesToCreate)
85.                 {
86.                     graphView.AddElement(edge1);
87.                     edge.input.Connect(edge1);
88.                     edge.output.Connect(edge1);
89.                 }
90.             }
91.         }
92.     }
93. }
94.  

You then have to

override InstantiatePort(...)

in a class derived from base class

Node

Code (CSharp):

1. public override Port InstantiatePort(Orientation orientation, Direction direction, Port.Capacity capacity, Type type)
2. {
3.     return PortView.Create<Edge>(orientation, direction, capacity, type);
4. }

Voilà, it prints!

 

Thank you! I just found the "VFXDataAnchor" and I was about to copy it and see if i could get it to work. You saved me tons of time!

 

I was wrong about one thing. For what you want, you'll want to use

public void OnDropOutsidePort(Edge edge, Vector2 position)

inside the

DefaultEdgeConnectorListener

class I previously posted. This class implements the

IEdgeConnector

interface which is the key for this to work.