Do not propagate data to multiple outputs because of one new connection (paceholder#312)

We have a source node A and consumer nodes B1 B2 B3.
If a node B4 is created and connected, all B-nodes receive the inpute
data propagated. This was wrong.

The correct behavior is just to notify the new B4 node.

Author: paceholder

examples/calculator/NumberDisplayDataModel.cpp

@@ -53,6 +53,7 @@ void
 NumberDisplayDataModel::
 setInData(std::shared_ptr<NodeData> data, PortIndex portIndex)
 {
+  qWarning() << this;
   _numberData = std::dynamic_pointer_cast<DecimalData>(data);
 
   if (!_label)

examples/calculator/NumberSourceDataModel.cpp

@@ -85,7 +85,10 @@ onTextEdited(QString const& str)
   {
     _number = std::make_shared<DecimalData>(number);
 
+    qWarning() << "================";
+
     Q_EMIT dataUpdated(0);
+
   }
   else
   {

src/DataFlowGraphModel.cpp

@@ -145,8 +145,16 @@ addConnection(ConnectionId const connectionId)
 
   Q_EMIT connectionCreated(connectionId);
 
-  onOutPortDataUpdated(getNodeId(PortType::Out, connectionId),
-                       getPortIndex(PortType::Out, connectionId));
+  QVariant const portDataToPropagate = portData(connectionId.outNodeId,
+                                                PortType::Out,
+                                                connectionId.outPortIndex,
+                                                PortRole::Data);
+
+  setPortData(connectionId.inNodeId,
+              PortType::In,
+              connectionId.inPortIndex,
+              portDataToPropagate,
+              PortRole::Data);
 }