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/*
 * Copyright (c) 1997-1999 The Java Apache Project.  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. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the Java Apache 
 *    Project for use in the Apache JServ servlet engine project
 *    (http://java.apache.org/)."
 *
 * 4. The names "Apache JServ", "Apache JServ Servlet Engine" and 
 *    "Java Apache Project" must not be used to endorse or promote products 
 *    derived from this software without prior written permission.
 *
 * 5. Products derived from this software may not be called "Apache JServ"
 *    nor may "Apache" nor "Apache JServ" appear in their names without 
 *    prior written permission of the Java Apache Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the Java Apache 
 *    Project for use in the Apache JServ servlet engine project
 *    (http://java.apache.org/)."
 *    
 * THIS SOFTWARE IS PROVIDED BY THE JAVA APACHE PROJECT "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 JAVA APACHE PROJECT 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.
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Java Apache Group. For more information
 * on the Java Apache Project and the Apache JServ Servlet Engine project,
 * please see .
 */

/*
 * Copyright 2000,2005 wingS development team.
 *
 * This file is part of wingS (http://wingsframework.org).
 *
 * wingS 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.
 *
 * Please see COPYING for the complete licence.
 */
package org.wings.template.parser;

import java.io.IOException;
import java.io.Reader;

/**
 * PositionReader can be asked for the
 * current position in the stream.
 *
 * @author Henner Zeller
 */
public class PositionReader
        extends Reader {

    private Reader reader = null;
    private long position;
    private long savePosition = -1;

    public PositionReader(Reader r) {
        this.reader = r;
        position = 0;
    }

    /* ---- PositionReader ---- */
    public long getPosition() {
        return position;
    }

    /* ---- Implementation of Reader ---- */

    @Override
    public int read()
            throws IOException {
        int c = reader.read();
        if (c != -1) position++;
        return c;
    }

    @Override
    public int read(char cbuff[])
            throws IOException {
        int num = reader.read(cbuff);
        if (num > 0) position += num;
        return num;
    }

    @Override
    public int read(char cbuff[], int off, int len)
            throws IOException {
        int num = reader.read(cbuff, off, len);
        if (num > 0) position += num;
        return num;
    }

    @Override
    public long skip(long n)
            throws IOException {
        long skipped = reader.skip(n);
        position += skipped;
        return skipped;
    }

    @Override
    public boolean ready()
            throws IOException {
        return reader.ready();
    }

    @Override
    public boolean markSupported() {
        return reader.markSupported();
    }

    @Override
    public void mark(int readAheadLimit)
            throws IOException {
        savePosition = position;
        reader.mark(readAheadLimit);
    }

    @Override
    public void reset()
            throws IOException {
        reader.reset();
        // this should be noticed by the reader before
        if (savePosition < 0)
            throw new IOException("mark() not set before");
        position = savePosition;
    }

    @Override
    public void close()
            throws IOException {
        reader.close();
    }
}