getContentPane().add(toolbar, BorderLayout.NORTH);
getContentPane().add(mediator.getComponentBar(), BorderLayout.NORTH);
mainPane = new JPanel(new BorderLayout());
getContentPane().add(mainPane, BorderLayout.CENTER);
ml = new GraphMouseListner(mediator);
mediator.setMouseListner(ml);
scroll = new JScrollPane();
mainPane.add(scroll, BorderLayout.CENTER);
centerWindow(800, 600);