BehaviorTree
diff --git a/‎src/NodeConnectionInteraction.cpp‎
Lines changed: 4 additions & 3 deletions b/‎src/NodeConnectionInteraction.cpp‎
Lines changed: 4 additions & 3 deletions
diff --git a/‎src/NodeDataModel.hpp‎
Lines changed: 9 additions & 0 deletions b/‎src/NodeDataModel.hpp‎
Lines changed: 9 additions & 0 deletions
diff --git a/‎src/NodeGraphicsObject.cpp‎
Lines changed: 22 additions & 16 deletions b/‎src/NodeGraphicsObject.cpp‎
Lines changed: 22 additions & 16 deletions
diff --git a/‎src/NodePainter.cpp‎
Lines changed: 6 additions & 3 deletions b/‎src/NodePainter.cpp‎
Lines changed: 6 additions & 3 deletions
@@ -238,7 +238,6 @@ nodePortIndexUnderScenePoint(PortType portType,
   PortIndex portIndex = nodeGeom.checkHitScenePoint(portType,
                                                     scenePoint,
                                                     sceneTransform);
-
   return portIndex;
 }
 
@@ -251,6 +250,8 @@ nodePortIsEmpty(PortType portType, PortIndex portIndex) const
 
   auto const & entries = nodeState.getEntries(portType);
 
-  return (portType == PortType::Out) ||
-         (entries[portIndex].empty());
+  if (entries[portIndex].empty()) return true;
+
+  const auto outPolicy = _node->nodeDataModel()->portOutConnectionPolicy(portIndex);
+  return ( portType == PortType::Out && outPolicy == NodeDataModel::Many);
 }
@@ -77,6 +77,15 @@ class NODE_EDITOR_PUBLIC NodeDataModel
   NodeDataType
   dataType(PortType portType, PortIndex portIndex) const = 0;
 
+  enum NodeConnectionPolicy {
+      One,
+      Many,
+  };
+
+  virtual NodeConnectionPolicy portOutConnectionPolicy(PortIndex /*portIndex*/) const {
+      return NodeConnectionPolicy::Many;
+  }
+
 public:
 
   /// Triggers the algorithm
 
@@ -201,28 +201,34 @@ mousePressEvent(QGraphicsSceneMouseEvent * event)
       std::unordered_map<QUuid, Connection*> connections =
         nodeState.connections(portToCheck, portIndex);
 
+
       // start dragging existing connection
-      if (!connections.empty() && portToCheck == PortType::In)
+      if ( !connections.empty() && portToCheck == PortType::In )
       {
-        auto con = connections.begin()->second;
+          auto con = connections.begin()->second;
 
-        NodeConnectionInteraction interaction(_node, *con, _scene);
+          NodeConnectionInteraction interaction(_node, *con, _scene);
 
-        interaction.disconnect(portToCheck);
+          interaction.disconnect(portToCheck);
       }
-      // initialize new Connection
-      else
+      else  // initialize new Connection
       {
-        // todo add to FlowScene
-        auto connection = _scene.createConnection(portToCheck,
-                                                  _node,
-                                                  portIndex);
-
-        _node.nodeState().setConnection(portToCheck,
-                                        portIndex,
-                                        *connection);
-
-        connection->getConnectionGraphicsObject().grabMouse();
+          const auto outPolicy = _node.nodeDataModel()->portOutConnectionPolicy(portIndex);
+          if ( !connections.empty() && (portToCheck == PortType::Out && outPolicy == NodeDataModel::One) )
+          {
+              _scene.deleteConnection( *connections.begin()->second );
+          }
+
+          // todo add to FlowScene
+          auto connection = _scene.createConnection(portToCheck,
+                                                    _node,
+                                                    portIndex);
+
+          _node.nodeState().setConnection(portToCheck,
+                                          portIndex,
+                                          *connection);
+
+          connection->getConnectionGraphicsObject().grabMouse();
       }
     }
   };
 
@@ -124,11 +124,14 @@ drawConnectionPoints(QPainter* painter,
 
       auto const & dataType = model->dataType(portType, i);
 
+      bool canConnect = (state.getEntries(portType)[i].empty() ||
+                         (portType == PortType::Out &&
+                          model->portOutConnectionPolicy(i) == NodeDataModel::Many) );
+
       double r = 1.0;
       if (state.isReacting() &&
-          (state.getEntries(portType)[i].empty() ||
-           portType == PortType::Out) &&
-           portType == state.reactingPortType())
+          canConnect &&
+          portType == state.reactingPortType())
       {
 
         auto   diff = geom.draggingPos() - p;