Graphical User Interfaces - Java Examples in a Nutshell - page 219

Example 10•16: Scribble.java (continued)

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public Scribble() {
super("Scribble"); // Call superclass constructor and set window title

// Handle window close requests
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) { System.exit(0); }

});

// All content of a JFrame (except for the menubar) goes in the
// Frame's internal "content pane", not in the frame itself.
// The same is true for JDialog and similar top-level containers.
Container contentPane = this.getContentPane();

// Specify a layout manager for the content pane
contentPane.setLayout(new BorderLayout());

// Create the main scribble pane component, give it a border, and
// a background color, and add it to the content pane
scribblePane = new ScribblePane2();
scribblePane.setBorder(new BevelBorder(BevelBorder.LOWERED));
scribblePane.setBackground(Color.white);
contentPane.add(scribblePane, BorderLayout.CENTER);

// Create a menubar and add it to this window. Note that JFrame
// handles menus specially and has a special method for adding them
// outside of the content pane.
JMenuBar menubar = new JMenuBar(); // Create a menubar
this.setJMenuBar(menubar); // Display it in the JFrame

// Create menus and add to the menubar
JMenu filemenu = new JMenu("File");
JMenu colormenu = new JMenu("Color");
menubar.add(filemenu);
menubar.add(colormenu);

// Create some Action objects for use in the menus and toolbars.
// An Action combines a menu title and/or icon with an ActionListener.
// These Action classes are defined as inner classes below.
Action clear = new ClearAction();
Action quit = new QuitAction();
Action black = new ColorAction(Color.black);
Action red = new ColorAction(Color.red);
Action blue = new ColorAction(Color.blue);
Action select = new SelectColorAction();

// Populate the menus using Action objects
filemenu.add(clear);
filemenu.add(quit);
colormenu.add(black);
colormenu.add(red);
colormenu.add(blue);
colormenu.add(select);

// Now create a toolbar, add actions to it, and add it to the
// top of the frame (where it appears underneath the menubar)
JToolBar toolbar = new JToolBar();
toolbar.add(clear);