nodeview: added setting for curved/straight edges

app/widget/nodeview/nodeviewscene.h

@@ -87,6 +87,8 @@ public:
 
   void SetFilterMode(const FilterMode& f);
 
+  bool GetEdgesAreCurved() const;
+
 public slots:
   /**
    * @brief Slot when a Node is added to a graph (SetGraph() connects this)
@@ -120,6 +122,11 @@ public slots:
    */
   void RemoveEdge(NodeEdgePtr edge);
 
+  /**
+   * @brief Set whether edges in this scene should be curved or not
+   */
+  void SetEdgesAreCurved(bool curved);
+
 private:
   static int DetermineWeight(Node* n);
 
@@ -133,6 +140,8 @@ private:
 
   FilterMode filter_mode_;
 
+  bool curved_edges_;
+
 private slots:
   /**
    * @brief Receiver for whenever a node position changes