inttextfield.java

sifi-0.1.6.tar.gz 出自http://www.ifi.unizh.ch/ikm/SINUS/firewall/ 一个linux的防火墙工具。

/*
 * Gary Cornell and Cay S. Horstmann, Core Java (Book/CD-ROM)
 * Published By SunSoft Press/Prentice-Hall
 * Copyright (C) 1996 Sun Microsystems Inc.
 * All Rights Reserved. ISBN 0-13-565755-5
 *
 * Permission to use, copy, modify, and distribute this 
 * software and its documentation for NON-COMMERCIAL purposes
 * and without fee is hereby granted provided that this 
 * copyright notice appears in all copies. 
 * 
 * THE AUTHORS AND PUBLISHER MAKE NO REPRESENTATIONS OR 
 * WARRANTIES ABOUT THE SUITABILITY OF THE SOFTWARE, EITHER 
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHORS
 * AND PUBLISHER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED 
 * BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING 
 * THIS SOFTWARE OR ITS DERIVATIVES.
 */
 
/**
 * A text field that accepts only integers
 * @version 1.01 15 Feb 1996 
 * @author Cay Horstmann
 */

package corejava;

import java.awt.*;


public class IntTextField extends TextField
{  /**
   * Creates the text field
   * @param def an integer default,
   * @param min the minimum int accepted
   * @param max the maximum int accepted
   * @param size the size of the text field
   */

   public IntTextField(int def, int min, int max, 
      int size)
   {  super("" + def, size);
      low = min;
      high = max;
   }

   /**
   * Checks if the data entered is valid or not
   * @return true data ok, false otherwise
   * @remark if invalid, the field gets focus so the user can fix it
   */
   
   public boolean isValid()
   {  int value;  
      try
      {  value = Integer.valueOf(getText().trim()).intValue();
         if (value < low || value > high)
            throw new NumberFormatException();
      }
      catch (NumberFormatException e)
      {  requestFocus();
         return false;
      }
      return true; 
   }

   /**
   * Get the integer data value
   * @return the integer data value
   * @remark if invalid, returns the valid prefix (or 0 if none)
   */
   
   public int getValue()
   {  return Format.atoi(getText());
   }
   
   private int low;
   private int high;
}