Chapter 22

State whether each of the following is true or false. If false, explain why. a) When the programmer creates a JFrame, a minimum of one menu must be created and added to the JFrame. b) The variable $f$ il 7 belongs to the GridBagLayout class. c) Drawing on a GUI component is performed with respect to the (0,0) upper- left corner coordinate of the component. d) The default layout for a Box is BoxLayout.

Find the error(s) in each of the following and explain how to correct the error(s). a) JMenubar b; b) mySTider $=$ JSTider (1000,222,100,450) c) gbc.fill = GridBagConstraints.NORTHWEST; // set fill d) // override to paint on a customized Swing component public void paintcomponent( Graphics g ) \{ g.drawString( "HELL0", 50, 50 ); 3 // end method paintComponent e) // create a JFrame and display it JFrame $f=$ new JFrame $(\text{ "AWindow" })$ $f.$ setVisible ( true )

Fill in the blanks in each of the following statements: a) $A$ JMenuItem that is a JMenu is called a(n) b) Method attaches a JMenuBar to a JFrame. c) Container class d) $A(n)$ manages a set of child windows declared with class JInternal Frame.

State whether each of the following is true or false. If false, explain why. a) Menus require a JMenuBar object so they can be attached to a JFrame. b) BoxLayout is the default layout manager for a JFrame. c) Method setEditable is a JTextComponent method. d) Class JFrame directly extends class Container. e) JApplets can contain menus.

Find the error(s) in each of the following. Explain how to correct the error(s). a) $x$. add $(\text{ new JMenuItem }(\text{ "Submenu Color" ) ); // createsubmenu }$ b) container.setLayout $(\mathrm{m}=\text{ new GridbagLayout }())$