--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/go/trove/io/PositionReader.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,135 @@
+/* ====================================================================
+ * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group
+ * ====================================================================
+ * The Tea Software License, Version 1.1
+ *
+ * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Walt Disney Internet Group (http://opensource.go.com/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact opensource@dig.com.
+ *
+ * 5. Products derived from this software may not be called "Tea",
+ *    "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
+ *    "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
+ *    written permission of the Walt Disney Internet Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * For more information about Tea, please see http://opensource.go.com/.
+ */
+
+package com.go.trove.io;
+
+import java.io.*;
+
+/******************************************************************************
+ * The PositionReader tracks the postion in the stream of the next character 
+ * to be read. PositionReaders chain together such that the position is
+ * read from the earliest PositionReader in the chain.
+ *
+ * <p>Position readers automatically close the underlying input stream when
+ * the end of file is reached. Ordinary input streams don't do this.
+ * 
+ * @author Brian S O'Neill
+ * @version
+ * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 12/11/00 <!-- $-->
+ */
+public class PositionReader extends FilterReader {
+    /** Is non-null when this PositionReader is chained to another. */
+    protected PositionReader mPosReader;
+
+    protected int mPosition = 0;
+
+    private boolean mClosed = false;
+
+    public PositionReader(Reader reader) {
+        super(reader);
+        if (reader instanceof PositionReader) {
+            mPosReader = (PositionReader)reader;
+        }
+    }
+
+    /**
+     * @return the position of the next character to be read.
+     */
+    public int getNextPosition() {
+        return mPosition;
+    }
+
+    public int read() throws IOException {
+        try {
+            int c;
+            if ((c = in.read()) != -1) {
+                if (mPosReader == null) {
+                    mPosition++;
+                }
+                else {
+                    mPosition = mPosReader.getNextPosition();
+                }
+            }
+            else {
+                close();
+            }
+            
+            return c;
+        }
+        catch (IOException e) {
+            if (mClosed) {
+                return -1;
+            }
+            else {
+                throw e;
+            }
+        }
+    }
+
+    public int read(char[] buf, int off, int length) throws IOException {
+        int i = 0;
+        while (i < length) {
+            int c;
+            if ((c = read()) == -1) {
+                return (i == 0)? -1 : i;
+            }
+            buf[i++ + off] = (char)c;
+        }
+
+        return i;
+    }
+
+    public void close() throws IOException {
+        mClosed = true;
+        super.close();
+    }
+}