ui: graph view edges

Added simple edges to the graph view. Also fixed a memory leak source in QtMainWindow.

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src/app/qt/view/QtGraphView.h

@@ -3,6 +3,8 @@
 
 #include "component/view/GraphView.h"
 
+class QGraphicsView;
+
 class QtGraphView : public GraphView
 {
 public:
@@ -13,7 +15,11 @@ public:
 	virtual void createWidgetWrapper();
 	virtual void initGui();
 
-	virtual void addNode(const Vec2i& position, const std::string& name);
+	virtual std::weak_ptr<GraphNode> addNode(const Vec2i& position, const std::string& name);
+	virtual void addEdge(const std::weak_ptr<GraphNode>& owner, const std::weak_ptr<GraphNode>& target);
+
+private:
+	QGraphicsView* getView();
 };
 
 #endif // QT_GRAPH_VIEW_H