public MainPanel() { super(new BorderLayout()); pop.add(new NewTabAction("Add", null)); pop.addSeparator(); pop.add(new CloseAllAction("Close All", null)); tabbedPane.setComponentPopupMenu(pop); tabbedPane.addTab("aaaaaa", new JScrollPane(new JTree())); tabbedPane.addTab("12345678901234567890", new JScrollPane(new JLabel("asdfasdfsadf"))); tabbedPane.addTab("b", new JScrollPane(new JTree())); // tab.setSelectedIndex(0); // TabPanel titleTab = (TabPanel) tab.getTabComponentAt(0); // titleTab.setButtonVisible(true); add(tabbedPane); setPreferredSize(new Dimension(320, 240)); }