// Fig. 22.2: OvalPanel.java // A customized JPanel class. import java.awt.Graphics; import java.awt.Dimension; import javax.swing.JPanel; public class OvalPanel extends JPanel { private int diameter = 10; // default diameter of 10 // draw an oval of the specified diameter public void paintComponent( Graphics g ) { super.paintComponent( g ); g.fillOval( 10, 10, diameter, diameter ); // draw circle } // end method paintComponent // validate and set diameter, then repaint public void setDiameter( int newDiameter ) { // if diameter invalid, default to 10 diameter = ( newDiameter >= 0 ? newDiameter : 10 ); repaint(); // repaint panel } // end method setDiameter // used by layout manager to determine preferred size public Dimension getPreferredSize() { return new Dimension( 200, 200 ); } // end method getPreferredSize // used by layout manager to determine minimum size public Dimension getMinimumSize() { return getPreferredSize(); } // end method getMinimumSize } // end class OvalPanel /************************************************************************** * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * *************************************************************************/