@Override public void actionPerformed(ActionEvent e) { final GraphViewerPanel viewerPanel = (GraphViewerPanel) frame.getTabbedPane().getSelectedComponent(); DAGLayout dagLayout = new DAGLayout(viewerPanel.getCurrentGraph()); MyVisualizationViewer vv = (MyVisualizationViewer) viewerPanel.getVisualizationViewer(); vv.setGraphLayout(dagLayout); vv.repaint(); } }