JTabbedPaneのタブタイトルを変更

class EditableTabbedPane extends JTabbedPane {
  private final JComponent glassPane = new EditorGlassPane();
  private final JTextField editor = new JTextField();
  private final Action startEditing = new AbstractAction() {
    @Override public void actionPerformed(ActionEvent e) {
      getRootPane().setGlassPane(glassPane);
      Rectangle rect = getBoundsAt(getSelectedIndex());
      Point p = SwingUtilities.convertPoint(
          EditableTabbedPane.this, rect.getLocation(), glassPane);
      // rect.setBounds(p.x + 2, p.y + 2, rect.width - 4, rect.height - 4);
      rect.setLocation(p);
      rect.grow(-2, -2);
      editor.setBounds(rect);
      editor.setText(getTitleAt(getSelectedIndex()));
      editor.selectAll();
      glassPane.add(editor);
      glassPane.setVisible(true);
      editor.requestFocusInWindow();
    }
  };
  private final Action cancelEditing = new AbstractAction() {
    @Override public void actionPerformed(ActionEvent e) {
      glassPane.setVisible(false);
    }
  };
  private final Action renameTab = new AbstractAction() {
    @Override public void actionPerformed(ActionEvent e) {
      if (!editor.getText().trim().isEmpty()) {
        setTitleAt(getSelectedIndex(), editor.getText());
        //java 1.6.0 ---->
        Component c = getTabComponentAt(getSelectedIndex());
        if (c instanceof JComponent) {
          ((JComponent) c).revalidate();
        }
        //<----
      }
      glassPane.setVisible(false);
    }
  };

  protected EditableTabbedPane() {
    super();
    editor.setBorder(BorderFactory.createEmptyBorder(0, 3, 0, 3));
    editor.getInputMap(JComponent.WHEN_FOCUSED).put(
        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "rename-tab");
    editor.getActionMap().put("rename-tab", renameTab);
    editor.getInputMap(JComponent.WHEN_FOCUSED).put(
        KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), "cancel-editing");
    editor.getActionMap().put("cancel-editing", cancelEditing);

    addMouseListener(new MouseAdapter() {
      @Override public void mouseClicked(MouseEvent e) {
        if (e.getClickCount() == 2) {
          startEditing.actionPerformed(
            new ActionEvent(e.getComponent(), ActionEvent.ACTION_PERFORMED, ""));
        }
      }
    });
    getInputMap(JComponent.WHEN_FOCUSED).put(
        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "start-editing");
    getActionMap().put("start-editing", startEditing);
  }

  private class EditorGlassPane extends JComponent {
    protected EditorGlassPane() {
      super();
      setOpaque(false);
      setFocusTraversalPolicy(new DefaultFocusTraversalPolicy() {
        @Override public boolean accept(Component c) {
          return Objects.equals(c, editor);
        }
      });
      addMouseListener(new MouseAdapter() {
        @Override public void mouseClicked(MouseEvent e) {
          // if (Objects.nonNull(rect) && !rect.contains(e.getPoint())) {
          if (!editor.getBounds().contains(e.getPoint())) {
            renameTab.actionPerformed(
              new ActionEvent(e.getComponent(), ActionEvent.ACTION_PERFORMED, ""));
          }
        }
      });
    }

    @Override public void setVisible(boolean flag) {
      super.setVisible(flag);
      setFocusTraversalPolicyProvider(flag);
      setFocusCycleRoot(flag);
    }
  }
}