Move (de)serializtion for ConnectionId s to utils

ConnectionId s are serialized and deserialized now by the functions
located in `ConnectinoIdUtils.hpp`. The functions shoundn't be a
part of the public `AbstractGaphModel` API due to their simplicity.

Besides some unification of the code for new generated NodeIds has been
made.

Author: paceholder

examples/dynamic_ports/DynamicPortsModel.cpp

@@ -385,34 +385,6 @@ loadNode(QJsonObject const & nodeJson)
 }
 
 
-QJsonObject
-DynamicPortsModel::
-saveConnection(ConnectionId const & connId) const
-{
-  QJsonObject connJson;
-
-  connJson["outNodeId"] = static_cast<qint64>(connId.outNodeId);
-  connJson["outPortIndex"] = static_cast<qint64>(connId.outPortIndex);
-  connJson["intNodeId"] = static_cast<qint64>(connId.inNodeId);
-  connJson["inPortIndex"] = static_cast<qint64>(connId.inPortIndex);
-
-  return connJson;
-}
-
-
-void
-DynamicPortsModel::
-loadConnection(QJsonObject const & connJson)
-{
-  ConnectionId connId{static_cast<NodeId>(connJson["outNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["outPortIndex"].toInt()),
-                      static_cast<NodeId>(connJson["intNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["inPortIndex"].toInt())};
-
-  addConnection(connId);
-}
-
-
 void
 DynamicPortsModel::
 addPort(NodeId nodeId,

examples/dynamic_ports/DynamicPortsModel.hpp

@@ -106,12 +106,6 @@ class DynamicPortsModel : public QtNodes::AbstractGraphModel
   void
   loadNode(QJsonObject const & nodeJson) override;
 
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const override;
-
-  void
-  loadConnection(QJsonObject const & connJson) override;
-
   void
   addPort(NodeId nodeId,
           PortType portType,
@@ -122,6 +116,8 @@ class DynamicPortsModel : public QtNodes::AbstractGraphModel
              PortType portType,
              PortIndex first);
 
+  NodeId newNodeId() override { return _nextNodeId++; }
+
 private:
   std::unordered_set<NodeId> _nodeIds;
 

examples/simple_graph_model/SimpleGraphModel.cpp

@@ -74,7 +74,7 @@ NodeId
 SimpleGraphModel::
 addNode(QString const nodeType)
 {
-  NodeId newId = _nextNodeId++;
+  NodeId newId = newNodeId();
   // Create new node.
   _nodeIds.insert(newId);
 
@@ -307,6 +307,7 @@ deleteNode(NodeId const nodeId)
 {
   // Delete connections to this node first.
   auto connectionIds = allConnectionIds(nodeId);
+
   for (auto & cId : connectionIds)
   {
     deleteConnection(cId);
@@ -366,31 +367,3 @@ loadNode(QJsonObject const & nodeJson)
                 pos);
   }
 }
-
-
-QJsonObject
-SimpleGraphModel::
-saveConnection(ConnectionId const & connId) const
-{
-  QJsonObject connJson;
-
-  connJson["outNodeId"] = static_cast<qint64>(connId.outNodeId);
-  connJson["outPortIndex"] = static_cast<qint64>(connId.outPortIndex);
-  connJson["intNodeId"] = static_cast<qint64>(connId.inNodeId);
-  connJson["inPortIndex"] = static_cast<qint64>(connId.inPortIndex);
-
-  return connJson;
-}
-
-
-void
-SimpleGraphModel::
-loadConnection(QJsonObject const & connJson)
-{
-  ConnectionId connId{static_cast<NodeId>(connJson["outNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["outPortIndex"].toInt()),
-                      static_cast<NodeId>(connJson["intNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["inPortIndex"].toInt())};
-
-  addConnection(connId);
-}

examples/simple_graph_model/SimpleGraphModel.hpp

@@ -107,11 +107,7 @@ class SimpleGraphModel : public QtNodes::AbstractGraphModel
   void
   loadNode(QJsonObject const & nodeJson) override;
 
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const override;
-
-  void
-  loadConnection(QJsonObject const & connJson) override;
+  NodeId newNodeId() override { return _nextNodeId++; }
 
 private:
   std::unordered_set<NodeId> _nodeIds;

examples/vertical_layout/SimpleGraphModel.cpp

@@ -346,7 +346,7 @@ void
 SimpleGraphModel::
 loadNode(QJsonObject const & nodeJson)
 {
-  NodeId restoredNodeId = static_cast<NodeId>(nodeJson["id"].toInt());
+  NodeId restoredNodeId = nodeJson["id"].toInt();
 
   // Next NodeId must be larger that any id existing in the graph
   _nextNodeId = std::max(restoredNodeId + 1, _nextNodeId);
@@ -366,31 +366,3 @@ loadNode(QJsonObject const & nodeJson)
                 pos);
   }
 }
-
-
-QJsonObject
-SimpleGraphModel::
-saveConnection(ConnectionId const & connId) const
-{
-  QJsonObject connJson;
-
-  connJson["outNodeId"] = static_cast<qint64>(connId.outNodeId);
-  connJson["outPortIndex"] = static_cast<qint64>(connId.outPortIndex);
-  connJson["intNodeId"] = static_cast<qint64>(connId.inNodeId);
-  connJson["inPortIndex"] = static_cast<qint64>(connId.inPortIndex);
-
-  return connJson;
-}
-
-
-void
-SimpleGraphModel::
-loadConnection(QJsonObject const & connJson)
-{
-  ConnectionId connId{static_cast<NodeId>(connJson["outNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["outPortIndex"].toInt()),
-                      static_cast<NodeId>(connJson["intNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["inPortIndex"].toInt())};
-
-  addConnection(connId);
-}

examples/vertical_layout/SimpleGraphModel.hpp

@@ -107,17 +107,9 @@ class SimpleGraphModel : public QtNodes::AbstractGraphModel
   void
   loadNode(QJsonObject const & nodeJson) override;
 
-  /**
-   * Serializes @param connId to QJsonObject
-   */
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const override;
-
-  /**
-   * Restores connection from QJsonObject and adds it to the graph.
-   */
-  void
-  loadConnection(QJsonObject const & connJson) override;
+private:
+  NodeId
+  newNodeId() override { return _nextNodeId++; }
 
 private:
   std::unordered_set<NodeId> _nodeIds;

include/QtNodes/internal/AbstractGraphModel.hpp

@@ -30,6 +30,9 @@ class NODE_EDITOR_PUBLIC AbstractGraphModel : public QObject
 {
   Q_OBJECT
 public:
+  /// Generates a new unique NodeId.
+  virtual NodeId newNodeId() = 0;
+
   /// @brief Returns the full set of unique Node Ids.
   /**
    * Model creator is responsible for generating unique `unsigned int`
@@ -230,14 +233,6 @@ class NODE_EDITOR_PUBLIC AbstractGraphModel : public QObject
   void
   loadNode(QJsonObject const &) {}
 
-  virtual
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const = 0;
-
-  virtual
-  void
-  loadConnection(QJsonObject const & connJson) = 0;
-
 public:
   /**
    * Function clears connections attached to the ports that are scheduled to be

include/QtNodes/internal/ConnectionIdUtils.hpp

@@ -1,10 +1,12 @@
 #pragma once
 
+#include "Definitions.hpp"
+
+#include <QJsonObject>
+
 #include <iostream>
 #include <string>
 
-#include "Definitions.hpp"
-
 namespace QtNodes
 {
 
@@ -166,4 +168,32 @@ operator<<(std::ostream & ostr, ConnectionId const connectionId)
 }
 
 
+inline
+QJsonObject
+toJson(ConnectionId const & connId)
+{
+  QJsonObject connJson;
+
+  connJson["outNodeId"] = static_cast<qint64>(connId.outNodeId);
+  connJson["outPortIndex"] = static_cast<qint64>(connId.outPortIndex);
+  connJson["intNodeId"] = static_cast<qint64>(connId.inNodeId);
+  connJson["inPortIndex"] = static_cast<qint64>(connId.inPortIndex);
+
+  return connJson;
+}
+
+
+inline
+ConnectionId
+fromJson(QJsonObject const & connJson)
+{
+  ConnectionId connId{static_cast<NodeId>(connJson["outNodeId"].toInt(InvalidNodeId)),
+                      static_cast<PortIndex>(connJson["outPortIndex"].toInt(InvalidPortIndex)),
+                      static_cast<NodeId>(connJson["intNodeId"].toInt(InvalidNodeId)),
+                      static_cast<PortIndex>(connJson["inPortIndex"].toInt(InvalidPortIndex))};
+
+  return connId;
+}
+
+
 }

include/QtNodes/internal/DataFlowGraphModel.hpp

@@ -104,12 +104,6 @@ class NODE_EDITOR_PUBLIC DataFlowGraphModel
   void
   load(QJsonObject const &json) override;
 
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const override;
-
-  void
-  loadConnection(QJsonObject const & connJson) override;
-
   /**
    * Fetches the NodeDelegateModel for the given `nodeId` and tries to cast the
    * stored pointer to the given type
@@ -134,20 +128,7 @@ class NODE_EDITOR_PUBLIC DataFlowGraphModel
                    PortIndex const);
 
 private:
-  NodeId
-  newNodeId() { return _nextNodeId++; }
-
-  /**
-   * The function could be used when we restore nodes from some file
-   * and the NodeId values are already known.  In this case we must
-   * update internal counter for unique "next" node id in order not to
-   * repeat the values when incrementing.
-   */
-  void
-  setNextNodeId(NodeId const restoredNodeId)
-  {
-    _nextNodeId = std::max(_nextNodeId, restoredNodeId + 1);
-  }
+  NodeId newNodeId() override { return _nextNodeId++; }
 
 private Q_SLOTS:
   /**

src/DataFlowGraphModel.cpp

@@ -479,7 +479,7 @@ save() const
   QJsonArray connJsonArray;
   for (auto const & cid : _connectivity)
   {
-    connJsonArray.append(saveConnection(cid));
+    connJsonArray.append(toJson(cid));
   }
   sceneJson["connections"] = connJsonArray;
 
@@ -538,48 +538,25 @@ load(QJsonObject const &jsonDocument)
 {
   QJsonArray nodesJsonArray = jsonDocument["nodes"].toArray();
 
-  for (QJsonValueRef node : nodesJsonArray)
+  for (QJsonValueRef nodeJson : nodesJsonArray)
   {
-    loadNode(node.toObject());
+    loadNode(nodeJson.toObject());
   }
 
   QJsonArray connectionJsonArray = jsonDocument["connections"].toArray();
 
   for (QJsonValueRef connection : connectionJsonArray)
   {
-    loadConnection(connection.toObject());
-  }
-}
-
-
-
-QJsonObject
-DataFlowGraphModel::
-saveConnection(ConnectionId const & connId) const
-{
-  QJsonObject connJson;
+    QJsonObject connJson = connection.toObject();
 
-  connJson["outNodeId"] = static_cast<qint64>(connId.outNodeId);
-  connJson["outPortIndex"] = static_cast<qint64>(connId.outPortIndex);
-  connJson["intNodeId"] = static_cast<qint64>(connId.inNodeId);
-  connJson["inPortIndex"] = static_cast<qint64>(connId.inPortIndex);
+    ConnectionId connId = fromJson(connJson);
 
-  return connJson;
+    // Restore the connection
+    addConnection(connId);
+  }
 }
 
 
-void
-DataFlowGraphModel::
-loadConnection(QJsonObject const & connJson)
-{
-  ConnectionId connId{static_cast<NodeId>(connJson["outNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["outPortIndex"].toInt()),
-                      static_cast<NodeId>(connJson["intNodeId"].toInt()),
-                      static_cast<PortIndex>(connJson["inPortIndex"].toInt())};
-
-  addConnection(connId);
-}
-
 
 void
 DataFlowGraphModel::