/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.codehaus.groovy.runtime;

import java.io.IOException;
import java.io.Writer;

/**
 * This class codes around a silly limitation of StringWriter which doesn't allow a StringBuffer
 * to be passed in as a constructor for some bizarre reason.
 * So we replicate the behaviour of StringWriter here but allow a StringBuffer to be passed in.
 * 
 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
 */
public class StringBufferWriter extends Writer {

    private StringBuffer buffer;

    /**
     * Create a new string writer which will append the text to the given StringBuffer
     */
    public StringBufferWriter(StringBuffer buffer) {
        this.buffer = buffer;
    }

    /**
     * Write a single character.
     */
    public void write(int c) {
        buffer.append((char) c);
    }

    /**
     * Write a portion of an array of characters.
     *
     * @param text Array of characters
     * @param offset Offset from which to start writing characters
     * @param length Number of characters to write
     */
    public void write(char text[], int offset, int length) {
        if ((offset < 0) || (offset > text.length) || (length < 0) || ((offset + length) > text.length) || ((offset + length) < 0)) {
            throw new IndexOutOfBoundsException();
        }
        else if (length == 0) {
            return;
        }
        buffer.append(text, offset, length);
    }

    /**
     * Write a string.
     */
    public void write(String text) {
        buffer.append(text);
    }

    /**
     * Write a portion of a string.
     *
     * @param text the text to be written
     * @param offset offset from which to start writing characters
     * @param length Number of characters to write
     */
    public void write(String text, int offset, int length) {
        buffer.append(text.substring(offset, offset + length));
    }

    /**
     * Return the buffer's current value as a string.
     */
    public String toString() {
        return buffer.toString();
    }

    /**
     * Flush the stream.
     */
    public void flush() {
    }

    /**
     * Closing a <tt>StringWriter</tt> has no effect. The methods in this
     * class can be called after the stream has been closed without generating
     * an <tt>IOException</tt>.
     */
    public void close() throws IOException {
    }
}
