Swing I - Java - page 904

Setting the Title of a JFrame
The two most common ways to set the title of a JFrame are to use the method setTitle , as
illustrated in Display 17.4, or to give the title as an argument to the base class constructor
super , as illustrated in Display 17.6.

Self-Test Exercises
12. How would you modify the class definition in Display 17.6 so that the window
produced by the no-argument constructor is magenta instead of pink?
13. Rewrite the following two lines from Display 17.6 so that the label does not have
the name aLabel or any other name. Hint: Use an anonymous object.

JLabel aLabel = new JLabel("Close-window button works.");
add(aLabel);

Display 17.6 A JFrame with Color (part 1 of 2)

1 import javax.swing.JFrame;

2 import javax.swing.JLabel;

3 import java.awt.Color;

4 public class ColoredWindow extends JFrame
5{
6 public static final int WIDTH = 300;

7 public static final int HEIGHT = 200;

8 public ColoredWindow(Color theColor)

9 {

10 super ("No Charge for Color");

11 setSize(WIDTH, HEIGHT);

12 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

13 getContentPane().setBackground(theColor);

JLabel aLabel = new JLabel("Close-window button works.");

14

15 add(aLabel);

16 }

17 public ColoredWindow()

This is an invocation of the other
constructor.

18 {

19 this (Color.GREEN);

20 }

21 }

This is the file ColoredWindow.java .