/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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 com.sun.org.apache.xalan.internal.xsltc.runtime;

import org.xml.sax.SAXException;

import com.sun.org.apache.xml.internal.serializer.EmptySerializer;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @author Morten Jorgensen

 */

public final class StringValueHandler extends EmptySerializer {

    private StringBuilder _buffer = new StringBuilder();

    private String _str = null;

    private static final String EMPTY_STR = "";

    private boolean m_escaping = false;

    private int _nestedLevel = 0;

    public void characters(char[] ch, int off, int len)

        throws SAXException

    {

        if (_nestedLevel > 0)

            return;

        if (_str != null) {

            _buffer.append(_str);

            _str = null;

        }

        _buffer.append(ch, off, len);

    }

    public String getValue() {

        if (_buffer.length() != 0) {

            String result = _buffer.toString();

            _buffer.setLength(0);

            return result;

        }

        else {

            String result = _str;

            _str = null;

            return (result != null) ? result : EMPTY_STR;

        }

    }

    public void characters(String characters) throws SAXException {

        if (_nestedLevel > 0)

            return;

        if (_str == null && _buffer.length() == 0) {

            _str = characters;

        }

        else {

            if (_str != null) {

                _buffer.append(_str);

                _str = null;

            }

            _buffer.append(characters);

        }

    }

    public void startElement(String qname) throws SAXException {

        _nestedLevel++;

    }

    public void endElement(String qname) throws SAXException {

        _nestedLevel--;

    }

    // Override the setEscaping method just to indicate that this class is

    // aware that that method might be called.

    public boolean setEscaping(boolean bool) {

        boolean oldEscaping = m_escaping;

        m_escaping = bool;

        return bool;

    }

    /**

     * The value of a PI must not contain the substring "?>". Should

     * that substring be present, replace it by "? >".

     */

    public String getValueOfPI() {

        final String value = getValue();

        if (value.indexOf("?>") > 0) {

            final int n = value.length();

            final StringBuilder valueOfPI = new StringBuilder();

            for (int i = 0; i < n;) {

                final char ch = value.charAt(i++);

                if (ch == '?' && value.charAt(i) == '>') {

                    valueOfPI.append("? >"); i++;

                }

                else {

                    valueOfPI.append(ch);

                }

            }

            return valueOfPI.toString();

        }

        return value;

    }

}