Add save load interface functions to AbstractModel

Author: paceholder

examples/graph/CustomGraphModel.cpp

@@ -3,7 +3,7 @@
 
 CustomGraphModel::
 CustomGraphModel()
-  : _lastNodeId{0}
+  : _nextNodeId{0}
 {}
 
 
@@ -105,7 +105,7 @@ NodeId
 CustomGraphModel::
 addNode(QString const nodeType)
 {
-  NodeId newId = _lastNodeId++;
+  NodeId newId = _nextNodeId++;
   // Create new node.
   _nodeIds.insert(newId);
 
@@ -388,3 +388,71 @@ deleteNode(NodeId const nodeId)
 
   return true;
 }
+
+
+QJsonObject
+CustomGraphModel::
+saveNode(NodeId const nodeId) const
+{
+  QJsonObject nodeJson;
+
+  nodeJson["id"] = static_cast<qint64>(nodeId);
+
+  QPointF const pos =
+    nodeData(nodeId, NodeRole::Position).value<QPointF>();
+
+  QJsonObject posJson;
+  posJson["x"] = pos.x();
+  posJson["y"] = pos.y();
+  nodeJson["position"] = posJson;
+
+  return nodeJson;
+}
+
+
+void
+CustomGraphModel::
+loadNode(QJsonObject const & nodeJson)
+{
+  NodeId nodeId = static_cast<NodeId>(nodeJson["id"].toInt());
+
+  _nextNodeId = std::max(_nextNodeId, nodeId);
+
+  NodeId newId = addNode();
+
+  QJsonObject posJson = nodeJson["position"].toObject();
+  QPointF const pos(posJson["x"].toInt(),
+                    posJson["y"].toInt());
+
+  setNodeData(newId,
+              NodeRole::Position,
+              pos);
+}
+
+
+QJsonObject
+CustomGraphModel::
+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
+CustomGraphModel::
+loadConnection(QJsonObject const & connJson)
+{
+  ConnectionId connId{connJson["outNodeId"].toInt(),
+                      connJson["outPortIndex"].toInt(),
+                      connJson["intNodeId"].toInt(),
+                      connJson["inPortIndex"].toInt()};
+
+  addConnection(connId);
+}

examples/graph/CustomGraphModel.hpp

@@ -2,6 +2,7 @@
 
 #include <QtCore/QPointF>
 #include <QtCore/QSize>
+#include <QtCore/QJsonObject>
 
 #include <QtNodes/AbstractGraphModel>
 #include <QtNodes/StyleCollection>
@@ -95,6 +96,18 @@ class CustomGraphModel : public QtNodes::AbstractGraphModel
   bool
   deleteNode(NodeId const nodeId) override;
 
+  QJsonObject
+  saveNode(NodeId const) const override;
+
+  void
+  loadNode(QJsonObject const & nodeJson) override;
+
+  QJsonObject
+  saveConnection(ConnectionId const & connId) const override;
+
+  void
+  loadConnection(QJsonObject const & connJson) override;
+
 private:
 
   std::unordered_set<NodeId> _nodeIds;
@@ -108,6 +121,6 @@ class CustomGraphModel : public QtNodes::AbstractGraphModel
   _nodeGeometryData;
 
 
-  unsigned int _lastNodeId;
+  unsigned int _nextNodeId;
 
 };

include/QtNodes/internal/AbstractGraphModel.hpp

@@ -160,6 +160,30 @@ class NODE_EDITOR_PUBLIC AbstractGraphModel : public QObject
   bool
   deleteNode(NodeId const nodeId) = 0;
 
+  /**
+   * Reimplement the function if you want to store/restore the node's
+   * inner state during undo/redo node deletion operations.
+   */
+  virtual
+  QJsonObject
+  saveNode(NodeId const) const = 0;
+
+  /**
+   * Reimplement the function if you want to store/restore the node's
+   * inner state during undo/redo node deletion operations.
+   */
+  virtual
+  void
+  loadNode(QJsonObject const & nodeJson) = 0;
+
+  virtual
+  QJsonObject
+  saveConnection(ConnectionId const & connId) const = 0;
+
+  virtual
+  void
+  loadConnection(QJsonObject const & connJson) = 0;
+
 Q_SIGNALS:
 
   void

include/QtNodes/internal/DataFlowGraphModel.hpp

@@ -93,6 +93,19 @@ class NODE_EDITOR_PUBLIC DataFlowGraphModel : public AbstractGraphModel
 
   void
   load(QJsonDocument const &json);
+
+  QJsonObject
+  saveNode(NodeId const) const override;
+
+  void
+  loadNode(QJsonObject const & nodeJson) override;
+
+  QJsonObject
+  saveConnection(ConnectionId const & connId) const override;
+
+  void
+  loadConnection(QJsonObject const & connJson) override;
+
 private:
 
   NodeId
@@ -105,23 +118,10 @@ class NODE_EDITOR_PUBLIC DataFlowGraphModel : public AbstractGraphModel
   NodeId
   newNodeId(NodeId const restoredNodeId)
   {
-    _nextNodeId = restoredNodeId;
-    return _nextNodeId++;
+    _nextNodeId = std::max(_nextNodeId, restoredNodeId);
+    return restoredNodeId;
   }
 
-
-  QJsonObject
-  saveNode(NodeId const) const;
-
-  void
-  loadNode(QJsonObject const & nodeJson);
-
-  QJsonObject
-  saveConnection(ConnectionId const & connId) const;
-
-  void
-  loadConnection(QJsonObject const & connJson);
-
 private Q_SLOTS:
   /**
    * Fuction is called by NodeDelegateModel when a node has new data to

include/QtNodes/internal/GraphicsView.hpp

@@ -34,18 +34,16 @@ class NODE_EDITOR_PUBLIC GraphicsView
   centerScene();
 
 public Q_SLOTS:
-
   void
   scaleUp();
 
   void
   scaleDown();
 
   void
-  deleteSelectedObjects();
+  onDeleteSelectedObjects();
 
 protected:
-
   void
   contextMenuEvent(QContextMenuEvent *event) override;
 
@@ -71,12 +69,10 @@ public Q_SLOTS:
   showEvent(QShowEvent *event) override;
 
 protected:
-
   BasicGraphicsScene *
   nodeScene();
 
 private:
-
   QAction* _clearSelectionAction;
   QAction* _deleteSelectionAction;
 

src/GraphicsView.cpp

@@ -83,16 +83,25 @@ setScene(BasicGraphicsScene *scene)
   delete _clearSelectionAction;
   _clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);
   _clearSelectionAction->setShortcut(Qt::Key_Escape);
-  connect(_clearSelectionAction, &QAction::triggered,
-          scene, &QGraphicsScene::clearSelection);
+
+  connect(_clearSelectionAction,
+          &QAction::triggered,
+          scene,
+          &QGraphicsScene::clearSelection);
+
   addAction(_clearSelectionAction);
 
+
+
   delete _deleteSelectionAction;
   _deleteSelectionAction = new QAction(QStringLiteral("Delete Selection"), this);
   _deleteSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
   _deleteSelectionAction->setShortcut(QKeySequence(QKeySequence::Delete));
-  connect(_deleteSelectionAction, &QAction::triggered,
-          this, &GraphicsView::deleteSelectedObjects);
+  connect(_deleteSelectionAction,
+          &QAction::triggered,
+          this,
+          &GraphicsView::onDeleteSelectedObjects);
+
   addAction(_deleteSelectionAction);
 }
 
@@ -189,7 +198,7 @@ scaleDown()
 
 void
 GraphicsView::
-deleteSelectedObjects()
+onDeleteSelectedObjects()
 {
   // Delete the selected connections first, ensuring that they won't be
   // automatically deleted when selected nodes are deleted (deleting a
@@ -348,4 +357,3 @@ nodeScene()
 {
   return dynamic_cast<BasicGraphicsScene*>(scene());
 }
-