scrollbar.java

          //show AST in GUI
					JFrame frame = new JFrame("Antlr AST");
					JPanel panel = new JPanel();
                    JScrollPane scrollPane = new JScrollPane(panel);
                    scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
                    scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER);
                    scrollPane.setBounds(50, 30, 300, 50);
					TreeViewer viewr = new TreeViewer(Arrays.asList(
							parser.getRuleNames()),tree);
					viewr.setScale(1.5);//scale a little
					panel.add(viewr);
					frame.add(scrollPane);
					frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
					frame.setSize(600,400);
					frame.setVisible(true);