Add CreateCommand

Author: zmoth

src/DataFlowGraphicsScene.cpp

@@ -4,6 +4,7 @@
 #include "GraphicsView.hpp"
 #include "NodeDelegateModelRegistry.hpp"
 #include "NodeGraphicsObject.hpp"
+#include "UndoCommands.hpp"
 
 #include <QtWidgets/QFileDialog>
 #include <QtWidgets/QGraphicsSceneMoveEvent>
@@ -130,14 +131,7 @@ createSceneMenu(QPointF const scenePos)
               return;
             }
 
-            NodeId nodeId = this->_graphModel.addNode(item->text(0));
-
-            if (nodeId != InvalidNodeId)
-            {
-              _graphModel.setNodeData(nodeId,
-                                      NodeRole::Position,
-                                      scenePos);
-            }
+            this->undoStack().push(new CreateCommand(this, item->text(0), scenePos));
 
             modelMenu->close();
           });

src/UndoCommands.cpp

@@ -149,6 +149,53 @@ computeAverageNodePosition(QJsonObject const & sceneJson)
 }
 
 
+//-------------------------------------
+
+
+CreateCommand::
+CreateCommand(BasicGraphicsScene* scene,
+              QString const name,
+              QPointF const & mouseScenePos)
+  : _scene(scene)
+  , _sceneJson(QJsonObject())
+{
+  _nodeId = _scene->graphModel().addNode(name);
+  if (_nodeId != InvalidNodeId)
+  {
+    _scene->graphModel().setNodeData(_nodeId, NodeRole::Position, mouseScenePos);
+  }
+  else
+  {
+    setObsolete(true);
+  }
+}
+
+
+void
+CreateCommand::
+undo()
+{
+  QJsonArray nodesJsonArray;
+  nodesJsonArray.append(_scene->graphModel().saveNode(_nodeId));
+  _sceneJson["nodes"] = nodesJsonArray;
+
+  _scene->graphModel().deleteNode(_nodeId);
+}
+
+
+void
+CreateCommand::
+redo()
+{
+  if(_sceneJson.empty() || _sceneJson["nodes"].toArray().empty())
+    return;
+
+  insertSerializedItems(_sceneJson, _scene);
+}
+
+
+//-------------------------------------
+
 
 DeleteCommand::
 DeleteCommand(BasicGraphicsScene* scene)

src/UndoCommands.hpp

@@ -14,6 +14,23 @@ namespace QtNodes
 class BasicGraphicsScene;
 
 
+class CreateCommand : public QUndoCommand
+{
+public:
+  CreateCommand(BasicGraphicsScene* scene,
+                QString const name,
+                QPointF const & mouseScenePos);
+
+  void undo() override;
+  void redo() override;
+
+private:
+  BasicGraphicsScene* _scene;
+  NodeId _nodeId;
+  QJsonObject _sceneJson;
+};
+
+
 /**
  * Selected scene objects are serialized and then removed from the scene.
  * The deleted elements could be restored in `undo`.