001 /**
002 * jline - Java console input library
003 * Copyright (c) 2002,2003 Marc Prud'hommeaux marc@apocalypse.org
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either
008 * version 2.1 of the License, or (at your option) any later version.
009 *
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
013 * Lesser General Public License for more details.
014 *
015 * You should have received a copy of the GNU Lesser General Public
016 * License along with this library; if not, write to the Free Software
017 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
018 */
019 package jline;
020
021 import java.io.*;
022 import java.util.*;
023
024 /**
025 * A CursorBuffer is a holder for a {@link StringBuffer} that
026 * also contains the current cursor position.
027 *
028 * @author <a href="mailto:marc@apocalypse.org">Marc Prud'hommeaux</a>
029 */
030 public class CursorBuffer
031 {
032 public int cursor = 0;
033 public final StringBuffer buffer = new StringBuffer ();
034
035
036 public int length ()
037 {
038 return buffer.length ();
039 }
040
041
042 public char current ()
043 {
044 if (cursor <= 0)
045 return 0;
046
047 return buffer.charAt (cursor - 1);
048 }
049
050
051 /**
052 * Insert the specific character into the buffer, setting the
053 * cursor position ahead one.
054 *
055 * @param c the character to insert
056 */
057 public void insert (char c)
058 {
059 buffer.insert (cursor++, c);
060 }
061
062
063 /**
064 * Insert the specified {@link String} into the buffer, setting
065 * the cursor to the end of the insertion point.
066 *
067 * @param str the String to insert. Must not be null.
068 */
069 public void insert (String str)
070 {
071 if (buffer.length () == 0)
072 buffer.append (str);
073 else
074 buffer.insert (cursor, str);
075
076 cursor += str.length ();
077 }
078
079
080 public String toString ()
081 {
082 return buffer.toString ();
083 }
084 }