can add node to selected node with the insert key

lib/qtgraph/graphwidget.cpp

@@ -16,7 +16,8 @@ namespace std {
   template <>
   struct hash<float2>
   {
-    std::size_t operator()(const float2& f2) const {
+    std::size_t operator()(const float2& f2) const
+    {
       std::size_t h1 = std::hash<float>()(f2.x);
       std::size_t h2 = std::hash<float>()(f2.y);
       return h1 ^ (h2 << 1);
@@ -25,10 +26,16 @@ namespace std {
 }
 
 // for the map
-bool operator< (const float2& v1, const float2& v2) {
+bool operator< (const float2& v1, const float2& v2)
+{
   return length(v1) < length(v2);
 }
 
+float2 inline float2FromQPointF(const QPointF& p)
+{
+  return float2(p.x(), p.y());
+}
+
 
 GraphWidget::GraphWidget(Graph<float2>* graph, QWidget *p)
     : QGraphicsView(p)
@@ -50,8 +57,8 @@ GraphWidget::GraphWidget(Graph<float2>* graph, QWidget *p)
 
 void GraphWidget::itemMoved(const QPointF oldPos, const QPointF newPos)
 {
-  float2 old_v = float2(oldPos.x(), oldPos.y());
-  float2 new_v = float2(newPos.x(), newPos.y());
+  float2 old_v = float2FromQPointF(oldPos);
+  float2 new_v = float2FromQPointF(newPos);
   m_graph->modifyVertex(old_v, new_v);
 }
 
@@ -84,6 +91,27 @@ void GraphWidget::keyPressEvent(QKeyEvent *e)
     case Qt::Key_Minus:
         zoomOut();
         break;
+    case Qt::Key_Insert: {
+      QList <QGraphicsItem* > selectedItems = scene()->selectedItems();
+      if (selectedItems.isEmpty())
+        break;
+
+      QGraphicsItem* selectedItem = selectedItems.first();
+      Node* selectedNode = dynamic_cast<Node*>(selectedItem);
+
+      const QPoint global_p = QCursor::pos();
+      const QPoint widget_p = mapFromGlobal(global_p);
+      const QPointF scene_p = mapToScene(widget_p);
+
+      Node *node = new Node(this);
+      scene()->addItem(node);
+      node->setPos(scene_p.x(), scene_p.y());
+      scene()->addItem(new Edge(selectedNode, node));
+
+      const float2 source_pos = float2FromQPointF(selectedItem->pos());
+      const float2 destination_pos = float2FromQPointF(scene_p);
+      m_graph->addEdge(source_pos, destination_pos);
+    }
     default:
         QGraphicsView::keyPressEvent(e);
     }

lib/qtgraph/graphwidget.hpp

@@ -15,6 +15,7 @@ public:
   GraphWidget(Graph<float2>* graph, QWidget *parent = 0);
 
   void itemMoved(const QPointF oldPos, const QPointF newPos);
+
   void updateFromGraph();
 
 public slots:

lib/qtgraph/node.cpp

@@ -9,10 +9,11 @@
 
 
 Node::Node(GraphWidget *graphWidget)
-    : graph(graphWidget)
+    : m_graphWidget(graphWidget)
 {
     setFlag(ItemIsMovable);
     setFlag(ItemSendsGeometryChanges);
+    setFlag(ItemIsSelectable);
     setCacheMode(DeviceCoordinateCache);
     setZValue(-1);
 }
@@ -42,18 +43,18 @@ QPainterPath Node::shape() const
     return path;
 }
 
-void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
+void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem* /*option*/, QWidget *)
 {
     painter->setPen(Qt::NoPen);
     painter->setBrush(Qt::darkGray);
     painter->drawEllipse(-7, -7, 20, 20);
 
     QRadialGradient gradient(-3, -3, 10);
-    if (option->state & QStyle::State_Sunken) {
+    if (isSelected()) {
         gradient.setCenter(3, 3);
         gradient.setFocalPoint(3, 3);
-        gradient.setColorAt(1, QColor(Qt::yellow).light(120));
-        gradient.setColorAt(0, QColor(Qt::darkYellow).light(120));
+        gradient.setColorAt(0, Qt::red);
+        gradient.setColorAt(1, Qt::darkRed);
     } else {
         gradient.setColorAt(0, Qt::yellow);
         gradient.setColorAt(1, Qt::darkYellow);
@@ -73,7 +74,7 @@ QVariant Node::itemChange(GraphicsItemChange change, const QVariant &value)
 
         const QPointF old_pos = pos();
         const QPointF new_pos = value.toPointF();
-        graph->itemMoved(old_pos, new_pos);
+        m_graphWidget->itemMoved(old_pos, new_pos);
         break;
       }
     default:

lib/qtgraph/node.hpp

@@ -32,7 +32,7 @@ protected:
 private:
   QList<Edge *> edgeList;
   QPointF newPos;
-  GraphWidget *graph;
+  GraphWidget *m_graphWidget;
 };
 
 #endif