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.]
   *
   * ----------------------
   * LineBreakIterator.java
   * ----------------------
   * (C)opyright 2003, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner;
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: LineBreakIterator.java,v 1.4 2005/11/03 09:55:26 mungady Exp $
   *
   * Changes
   * -------
   * 13-03-2003 : Initial version
   */
  package org.jfree.util;
  
  import java.util.Iterator;
  
  /**
   * An iterator that breaks text into lines.
   * The result is equal to BufferedReader.readLine().
   *
   * @author Thomas Morgner
   */
  public class LineBreakIterator implements Iterator
  {
    /** A useful constant. */
    public static final int DONE = -1;
  
    /** Storage for the text. */
    private char[] text;
  
    /** The current position. */
    private int position;
  
    /**
     * Default constructor.
     */
    public LineBreakIterator()
    {
      setText("");
    }
  
    /**
     * Creates a new line break iterator.
     *
     * @param text the text to be broken up.
     */
    public LineBreakIterator(final String text)
    {
      setText(text);
    }
  
    /**
     * Returns the position of the next break.
     *
     * @return A position.
     */
    public synchronized int nextPosition()
    {
      if (this.text == null)
      {
        return DONE;
      }
      if (this.position == DONE)
      {
        return DONE;
      }
  
      // recognize \n, \r, \r\n
  
      final int nChars = this.text.length;
      int nextChar = this.position;
  
      for (;;)
      {
        if (nextChar >= nChars)
        {
          /* End of text reached */
          this.position = DONE;
          return DONE;
        }
  
        boolean eol = false;
        char c = 0;
        int i;
  
        // search the next line break, either \n or \r
        for (i = nextChar; i < nChars; i++)
        {
          c = this.text[i];
          if ((c == '\n') || (c == '\r'))
          {
            eol = true;
            break;
          }
        }
  
        nextChar = i;
        if (eol)
        {
          nextChar++;
          if (c == '\r')
          {
            if ((nextChar < nChars) && (this.text[nextChar] == '\n'))
            {
              nextChar++;
            }
          }
          this.position = nextChar;
          return (this.position);
        }
      }
    }
  
    /**
     * Same like next(), but returns the End-Of-Text as
     * if there was a linebreak added (Reader.readLine() compatible)
     *
     * @return The next position.
     */
    public int nextWithEnd()
    {
      final int pos = this.position;
      if (pos == DONE)
      {
        return DONE;
      }
      if (pos == this.text.length)
      {
        this.position = DONE;
        return DONE;
      }
      final int retval = nextPosition();
      if (retval == DONE)
      {
        return this.text.length;
      }
      return retval;
    }
  
    /**
     * Returns the text to be broken up.
     *
     * @return The text.
     */
    public String getText()
    {
      return new String(this.text);
    }
  
    /**
     * Sets the text to be broken up.
     *
     * @param text  the text.
     */
    public void setText(final String text)
    {
      this.position = 0;
      this.text = text.toCharArray();
    }
  
    /**
     * Returns <tt>true</tt> if the iteration has more elements. (In other
     * words, returns <tt>true</tt> if <tt>next</tt> would return an element
     * rather than throwing an exception.)
     *
     * @return <tt>true</tt> if the iterator has more elements.
     */
    public boolean hasNext()
    {
      return (this.position != DONE);
    }
  
    /**
     * Returns the next element in the iteration.
     *
     * @return the next element in the iteration.
     */
    public Object next()
    {
      if (this.position == DONE)
      {
        // allready at the end ...
        return null;
      }
  
      final int lastFound = this.position;
      int pos = nextWithEnd();
      if (pos == DONE)
      {
        // the end of the text has been reached ...
        return new String(this.text, lastFound, this.text.length - lastFound);
      }
  
      // step one char back
      if (pos > 0)
      {
        final int end = lastFound;
        for (; ((pos) > end) && ((this.text[pos - 1] == '\n') || this.text[pos - 1] == '\r'); pos--)
        {
          // search the end of the current linebreak sequence ..
        }
      }
      //System.out.println ("text: " + new String (text));
      //System.out.println ("pos: " + pos + " lastFound: " + lastFound);
      return new String(this.text, lastFound, pos - lastFound);
    }
  
    /**
     *
     * Removes from the underlying collection the last element returned by the
     * iterator (optional operation).  This method can be called only once per
     * call to <tt>next</tt>.  The behavior of an iterator is unspecified if
     * the underlying collection is modified while the iteration is in
     * progress in any way other than by calling this method.
     *
     * @exception UnsupportedOperationException if the <tt>remove</tt>
     *    operation is not supported by this Iterator.
     * @exception IllegalStateException if the <tt>next</tt> method has not
     *    yet been called, or the <tt>remove</tt> method has already
     *    been called after the last call to the <tt>next</tt>
     *    method.
     */
    public void remove()
    {
        throw new UnsupportedOperationException("This iterator is read-only.");
    }
  }
  