ui: graph view edges

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

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src/lib/component/view/GraphView.h

@@ -1,8 +1,14 @@
 #ifndef GRAPH_VIEW_H
 #define GRAPH_VIEW_H
 
+#include <list>
+#include <memory>
+
 #include "component/view/View.h"
 
+class GraphEdge;
+class GraphNode;
+
 class GraphView : public View
 {
 public:
@@ -11,7 +17,12 @@ public:
 
 	virtual std::string getName() const;
 
-	virtual void addNode(const Vec2i& position, const std::string& name) = 0;
+	virtual std::weak_ptr<GraphNode> addNode(const Vec2i& position, const std::string& name) = 0;
+	virtual void addEdge(const std::weak_ptr<GraphNode>& owner, const std::weak_ptr<GraphNode>& target) = 0;
+
+protected:
+	std::list<std::shared_ptr<GraphNode> > m_nodes;
+	std::list<std::weak_ptr<GraphEdge> > m_edges;
 };
 
 #endif // GRAPH_VIEW_H