move subtree with shift

graphwidget.cpp

@@ -281,6 +281,19 @@ void GraphWidget::keyPressEvent(QKeyEvent *event)
             else if (event->key() == Qt::Key_Right) m_activeNode->moveBy(20, 0);
             contentChanged();
         }
+        else if (event->modifiers() &  Qt::ControlModifier &&
+                 event->modifiers() &  Qt::ShiftModifier)
+        {
+            QList <Node *> nodeList = m_activeNode->subtree();
+            foreach(Node *node, nodeList)
+            {
+                if (event->key() == Qt::Key_Up) node->moveBy(0, -20);
+                else if (event->key() == Qt::Key_Down) node->moveBy(0, 20);
+                else if (event->key() == Qt::Key_Left) node->moveBy(-20, 0);
+                else if (event->key() == Qt::Key_Right) node->moveBy(20, 0);
+                contentChanged();
+            }
+        }
         else // move scene
         {
             QGraphicsView::keyPressEvent(event);

node.cpp

@@ -308,6 +308,38 @@ Edge * Node::edgeTo(const Node *node) const
     return 0;
 }
 
+
+QList<Node *> Node::subtree() const
+{
+    /** @note QList crashes if modified while traversal,
+      * QMutableListIterator lacks push_back
+      */
+
+    std::list<Node *> list;
+    list.push_back(const_cast<Node *>(this));
+
+    // inorder
+    for(std::list<Node *>::const_iterator it = list.begin();
+        it != list.end();
+        it++)
+    {
+        QList<Edge *> edges = (*it)->edgesFrom();
+        if (!edges.empty())
+        {
+            foreach(Edge *edge, edges)
+            {
+                if (!edge->secondary())
+                {
+                    list.push_back( edge->destNode() != this ?
+                                        edge->destNode():
+                                        edge->sourceNode());
+                }
+            }
+        }
+    }
+    return QList<Node *>::fromStdList(list);
+}
+
 void Node::paint(QPainter *painter,
                  const QStyleOptionGraphicsItem *option,
                  QWidget *w)

node.h

@@ -42,6 +42,7 @@ public:
     QList<Edge *> edgesFrom(const bool &excludeSecondaries = true) const;
     QList<Edge *> edgesToThis(const bool &excludeSecondaries = true) const;
     Edge * edgeTo(const Node* node) const;
+    QList<Node *> subtree() const;
 
 protected: