content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/index.html
   *
   * This library is free software; you can redistribute it and/or modify it 
   * under the terms of the GNU Lesser General Public License as published by 
   * the Free Software Foundation; either version 2.1 of the License, or 
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but 
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
   * USA.  
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   * 
   * ---------------------------
   * LengthLimitingDocument.java
   * ---------------------------
   * (C)opyright 2003, 2004, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner;
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: LengthLimitingDocument.java,v 1.3 2005/10/18 13:18:34 mungady Exp $
   *
   * Changes
   * -------
   * 22-Jan-2003 : Initial version
   * 05-Feb-2003 : Documentation
   * 
   */
  
  package org.jfree.ui;
  
  import javax.swing.text.AttributeSet;
  import javax.swing.text.BadLocationException;
  import javax.swing.text.PlainDocument;
  
  /**
   * This Document restricts the size of the contained plain text to the given number of
   * characters.
   *
   * @author Thomas Morgner
   */
  public class LengthLimitingDocument extends PlainDocument {
  
      /** The maximum length. */
      private int maxlen;
  
      /**
       * Creates a new LengthLimitingDocument, with no limitation.
       */
      public LengthLimitingDocument() {
          this(-1);
      }
  
      /**
       * Creates a new LengthLimitingDocument with the given limitation. No more than
       * maxlen characters can be added to the document. If maxlen is negative, then
       * no length check is performed.
       *
       * @param maxlen the maximum number of elements in this document
       */
      public LengthLimitingDocument(final int maxlen) {
          super();
          this.maxlen = maxlen;
      }
  
      /**
       * Sets the maximum number of characters for this document. Existing characters
       * are not removed.
       *
       * @param maxlen the maximum number of characters in this document.
       */
      public void setMaxLength(final int maxlen) {
          this.maxlen = maxlen;
      }
  
      /**
       * Returns the defined maximum number characters for this document.
       * @return the maximum number of characters
       */
      public int getMaxLength() {
          return this.maxlen;
      }
  
      /**
       * Inserts the string into the document. If the length of the document would
       * violate the maximum characters restriction, then the string is cut down so
       * that
       * @param offs the offset, where the string should be inserted into the document
       * @param str the string that should be inserted
       * @param a the attribute set assigned for the document
       * @throws javax.swing.text.BadLocationException if the offset is not correct
       */
      public void insertString(final int offs, final String str, final AttributeSet a)
          throws BadLocationException {
          if (str == null) {
              return;
          }
  
          if (this.maxlen < 0) {
              super.insertString(offs, str, a);
          }
  
          final char[] numeric = str.toCharArray();
          final StringBuffer b = new StringBuffer();
          b.append(numeric, 0, Math.min(this.maxlen, numeric.length));
          super.insertString(offs, b.toString(), a);
      }
      
  }
  