Swing Menus and Toolbars - The Definitive Guide to Java Swing - page 203

Action action = new ShowAction(frame);
JButton button = new JButton(action);
toolbar.add(button);
Container contentPane = frame.getContentPane();
contentPane.add(toolbar, BorderLayout.NORTH);
JTextArea textArea = new JTextArea();
JScrollPane pane = new JScrollPane(textArea);
contentPane.add(pane, BorderLayout.CENTER);
frame.setSize(350, 150);
frame.setVisible(true);
}
};
EventQueue.invokeLater(runner);
}
}
JToolBar.Separator Class
The JToolBar class maintains its own separator to permit a custom look and feel for the
separator when on a JToolBar .
This separator is automatically created when you call the addSeparator() method of
JToolBar . In addition, there are two constructors for creating a JToolBar.Separator if you
want to manually create the component.
public JToolBar.Separator()
JSeparator toolBarSeparator = new JToolBar.Separator();
public JToolBar.Separator(Dimension size)
Dimension dimension = new Dimension(10, 10);
JSeparator toolBarSeparator = new JToolBar.Separator(dimension);
Both constructors create a horizontal separator. You can configure the size. If you don't
specify this, the look and feel decides what size to make the separator.
As with JPopupMenu.Separator , if you want to change the orientation of the separator, you
must call the setOrientation() method inherited from JSeparator , this time with an argument
of JToolBar.Separator.VERTICAL .
Summary
This chapter introduced the many Swing menu-related classes and their interrelationships,
and Swing's toolbar class. First, you learned about the JMenuBar and its selection model, and
learned how menu bars can be used within applets as well as applications.
Next, you explored the JMenuItem , which is the menu element the user selects, along with two
new event/listener pairs the system uses for dealing with events, MenuKeyEvent / MenuKeyListener
and MenuDragMouseEvent / MenuDragMouseListener . Then, you moved on to the JMenu compo-
nent, upon which JMenuItem instances are placed, along with its new event/listener pair,
MenuEvent / MenuListener , which is used to determine when a menu is about to be posted.