18. A7 Simple Two-Button Program

• Our next sample demonstrates a simple program with two buttons in a frame.

• Change Color button changes the color of the background.

• Quit button causes the program to exit.

• Swing demo A7 creates GUI window with two buttons:

  • SwingMain.java (download)

  • FrameApplication.java (download) extends javax.swing.JFrame

  • FrameTwoButtons.java (download) extends FrameApplication and implements ActionListener

• Notice few more changes that took place in FrameApplication class:

  1. Although setFrameDimension( ) remains, it is no longer invoked by the constructor, presuming that the derived class will do that.

  2. The

     
         JFrame.setVisible(true);
     
     

     is now a responsibility of the FrameTwoButtons constructor.