Implement Duplication command for undo/redo

Author: paceholder

docs/classes.rst

@@ -61,6 +61,24 @@ Basic Classes
 .. doxygenclass:: QtNodes::NodeConnectionInteraction
    :members:
 
+Undo Redo
+---------
+
+.. doxygenclass:: QtNodes::DeleteCommand
+   :members:
+
+.. doxygenclass:: QtNodes::DuplicateCommand
+   :members:
+
+.. doxygenclass:: QtNodes::DisconnectCommand
+   :members:
+
+.. doxygenclass:: QtNodes::ConnectCommand
+   :members:
+
+.. doxygenclass:: QtNodes::MoveNodeCommand
+   :members:
+
 Dataflow Classes
 ----------------
 

include/QtNodes/internal/GraphicsView.hpp

@@ -43,6 +43,9 @@ public Q_SLOTS:
   void
   onDeleteSelectedObjects();
 
+  void
+  onDuplicateSelectedObjects();
+
 protected:
   void
   contextMenuEvent(QContextMenuEvent *event) override;
@@ -75,6 +78,7 @@ public Q_SLOTS:
 private:
   QAction* _clearSelectionAction;
   QAction* _deleteSelectionAction;
+  QAction* _duplicateSelectionAction;
 
   QPointF _clickPos;
 };

src/GraphicsView.cpp

@@ -77,34 +77,50 @@ deleteSelectionAction() const
 
 void
 GraphicsView::
-setScene(BasicGraphicsScene *scene)
+setScene(BasicGraphicsScene * scene)
 {
   QGraphicsView::setScene(scene);
 
-  // setup actions
-  delete _clearSelectionAction;
-  _clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);
-  _clearSelectionAction->setShortcut(Qt::Key_Escape);
-
-  connect(_clearSelectionAction,
-          &QAction::triggered,
-          scene,
-          &QGraphicsScene::clearSelection);
+  {
+    // setup actions
+    delete _clearSelectionAction;
+    _clearSelectionAction = new QAction(QStringLiteral("Clear Selection"), this);
+    _clearSelectionAction->setShortcut(Qt::Key_Escape);
 
-  addAction(_clearSelectionAction);
+    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::onDeleteSelectedObjects);
+  {
+    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::onDeleteSelectedObjects);
+
+    addAction(_deleteSelectionAction);
+  }
 
-  addAction(_deleteSelectionAction);
+  {
+    delete _duplicateSelectionAction;
+    _duplicateSelectionAction = new QAction(QStringLiteral("Duplicate Selection"), this);
+    _duplicateSelectionAction->setShortcutContext(Qt::ShortcutContext::WidgetShortcut);
+    _duplicateSelectionAction->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_D));
+    connect(_duplicateSelectionAction,
+            &QAction::triggered,
+            this,
+            &GraphicsView::onDuplicateSelectedObjects);
+
+    addAction(_duplicateSelectionAction);
+  }
 
 
   auto undoAction = scene->undoStack().createUndoAction(this, tr("&Undo"));
@@ -217,7 +233,23 @@ onDeleteSelectedObjects()
 
 void
 GraphicsView::
-keyPressEvent(QKeyEvent *event)
+onDuplicateSelectedObjects()
+{
+  QPoint origin = mapFromGlobal(QCursor::pos());
+
+  QRect const viewRect = rect();
+  if (!viewRect.contains(origin))
+    origin = viewRect.center();
+
+  QPointF relativeOrigin = mapToScene(origin);
+
+  nodeScene()->undoStack().push(new DuplicateCommand(nodeScene(), relativeOrigin));
+}
+
+
+void
+GraphicsView::
+keyPressEvent(QKeyEvent * event)
 {
   switch (event->key())
   {

src/NodeGraphicsObject.cpp

@@ -404,6 +404,8 @@ hoverLeaveEvent(QGraphicsSceneHoverEvent* event)
 {
   _nodeState.setHovered(false);
 
+  setZValue(0.0);
+
   update();
 
   Q_EMIT nodeScene()->nodeHoverLeft(_nodeId);

src/UndoCommands.cpp

@@ -91,24 +91,208 @@ redo()
 {
   auto & graphModel = _scene->graphModel();
 
+  QJsonArray connectionJsonArray = _sceneJson["connections"].toArray();
+
+  for (QJsonValueRef connection : connectionJsonArray)
+  {
+    QJsonObject connJson = connection.toObject();
+
+    ConnectionId connId = fromJson(connJson);
+
+    graphModel.deleteConnection(connId);
+  }
+
+
   QJsonArray nodesJsonArray = _sceneJson["nodes"].toArray();
 
   for (QJsonValueRef node : nodesJsonArray)
   {
     QJsonObject nodeJson = node.toObject();
     graphModel.deleteNode(static_cast<NodeId>(nodeJson["id"].toInt()));
   }
+}
+
+
+//-------------------------------------
+
+
+DuplicateCommand::
+DuplicateCommand(BasicGraphicsScene* scene,
+                 QPointF const & mouseScenePos)
+  : _scene(scene)
+  , _mouseScenePos(mouseScenePos)
+{
+  auto & graphModel = _scene->graphModel();
+
+  std::unordered_set<NodeId> selectedNodes;
+
+  QJsonArray nodesJsonArray;
+  // Delete the nodes; this will delete many of the connections.
+  // Selected connections were already deleted prior to this loop,
+  for (QGraphicsItem * item : _scene->selectedItems())
+  {
+    if (auto n = qgraphicsitem_cast<NodeGraphicsObject*>(item))
+    {
+      nodesJsonArray.append(graphModel.saveNode(n->nodeId()));
+
+      selectedNodes.insert(n->nodeId());
+    }
+  }
+
+  QJsonArray connJsonArray;
+  // Delete the selected connections first, ensuring that they won't be
+  // automatically deleted when selected nodes are deleted (deleting a
+  // node deletes some connections as well)
+  for (QGraphicsItem * item : _scene->selectedItems())
+  {
+    if (auto c = qgraphicsitem_cast<ConnectionGraphicsObject*>(item))
+    {
+      auto const& cid = c->connectionId();
+
+      if (selectedNodes.count(cid.outNodeId) > 0 &&
+          selectedNodes.count(cid.inNodeId) > 0)
+      {
+        connJsonArray.append(toJson(cid));
+      }
+    }
+  }
+
+
+  _sceneJson["nodes"] = nodesJsonArray;
+  _sceneJson["connections"] = connJsonArray;
+}
+
+
+void
+DuplicateCommand::
+undo()
+{
+  auto & graphModel = _scene->graphModel();
+
+  QJsonArray connectionJsonArray = _newSceneJson["connections"].toArray();
+
+  for (QJsonValueRef connection : connectionJsonArray)
+  {
+    QJsonObject connJson = connection.toObject();
+
+    ConnectionId connId = fromJson(connJson);
+
+    graphModel.deleteConnection(connId);
+  }
+
+  QJsonArray nodesJsonArray = _newSceneJson["nodes"].toArray();
+
+  for (QJsonValueRef node : nodesJsonArray)
+  {
+    QJsonObject nodeJson = node.toObject();
+    graphModel.deleteNode(static_cast<NodeId>(nodeJson["id"].toInt()));
+  }
+}
+
+
+void
+DuplicateCommand::
+redo()
+{
+  _scene->clearSelection();
+
+  auto & graphModel = _scene->graphModel();
+
+  std::unordered_map<NodeId, NodeId> mapNodeIds;
+
+  QPointF averagePos;
+
+  QJsonArray nodesJsonArray = _sceneJson["nodes"].toArray();
+
+  // Cycle below replaces the NodeId with the new generated value
+  // and computes an average position of the old selected node group
+
+  QJsonArray newNodesJsonArray;
+  for (QJsonValueRef node : nodesJsonArray)
+  {
+    QJsonObject nodeJson = node.toObject();
+
+    NodeId oldNodeId = nodeJson["id"].toInt();
+
+    averagePos +=
+      QPointF(nodeJson["position"].toObject()["x"].toDouble(),
+              nodeJson["position"].toObject()["y"].toDouble());
+
+    NodeId newNodeId = graphModel.newNodeId();
+
+    mapNodeIds[oldNodeId] = newNodeId;
+
+    // Replace NodeId in json
+    nodeJson["id"] = static_cast<qint64>(newNodeId);
+
+    newNodesJsonArray.append(nodeJson);
+  }
+
+  averagePos /= static_cast<double>(nodesJsonArray.size());
+
+
+  // The cycle below replaces old NodeIds in connections with the new values
 
   QJsonArray connectionJsonArray = _sceneJson["connections"].toArray();
 
+  QJsonArray newConnJsonArray;
   for (QJsonValueRef connection : connectionJsonArray)
   {
     QJsonObject connJson = connection.toObject();
-    graphModel.deleteConnection(fromJson(connJson));
+
+    ConnectionId connId = fromJson(connJson);
+
+    ConnectionId newConnId{mapNodeIds[connId.outNodeId],
+                           connId.outPortIndex,
+                           mapNodeIds[connId.inNodeId],
+                           connId.inPortIndex};
+
+
+    newConnJsonArray.append(toJson(newConnId));
+  }
+
+  // Cycle below offsets the new node group to the position of the mouse cursor
+  QPointF const diff = _mouseScenePos - averagePos;
+
+  for (QJsonValueRef node : newNodesJsonArray)
+  {
+    QJsonObject obj = node.toObject();
+    NodeId const id = obj["id"].toInt();
+
+    QPointF oldPos(obj["position"].toObject()["x"].toDouble(),
+                   obj["position"].toObject()["y"].toDouble());
+
+    oldPos += diff;
+
+    QJsonObject posJson;
+    posJson["x"] = oldPos.x();
+    posJson["y"] = oldPos.y();
+    obj["position"] = posJson;
+
+
+    graphModel.loadNode(obj);
+
+    _scene->nodeGraphicsObject(id)->setZValue(1.0);
+  }
+
+  for (QJsonValueRef connection : newConnJsonArray)
+  {
+    QJsonObject connJson = connection.toObject();
+
+    ConnectionId connId = fromJson(connJson);
+
+    // Restore the connection
+    graphModel.addConnection(connId);
   }
+
+
+  _newSceneJson["nodes"] = newNodesJsonArray;
+  _newSceneJson["connections"] = newConnJsonArray;
 }
 
 
+//-------------------------------------
+
 
 
 DisconnectCommand::