This constructor creates the GUI for this application.
super("Scribble"); // Call superclass constructor and set window title
// 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 ScribblePane();
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);
// Add a sub-menu for selecting a look-and-feel.
// The LookAndFeelPrefs utility class is later in the chapter.
colormenu.add(new JSeparator());
colormenu.add(LookAndFeelPrefs.createLookAndFeelMenu(ScribbleApp.class,
new ActionListener() {
public void actionPerformed(ActionEvent e) {
SwingUtilities.updateComponentTreeUI(ScribbleApp.this);
}
}));
// 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);
toolbar.add(select);
toolbar.add(quit);
contentPane.add(toolbar, BorderLayout.NORTH);
// Create another toolbar for use as a color palette and add to
// the left side of the window.
JToolBar palette = new JToolBar();
palette.add(black);
palette.add(red);
palette.add(blue);
palette.setOrientation(SwingConstants.VERTICAL);
contentPane.add(palette, BorderLayout.WEST);
