/*
 * 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.apache.xerces.impl.xs;

import java.util.AbstractList;

import org.apache.xerces.xs.StringList;

/**
 * StringList implementation for schema error codes and error messages.
 *
 * @xerces.internal
 *
 * @author Michael Glavassevich, IBM
 * 
 * @version $Id: PSVIErrorList.java 726309 2008-12-13 23:54:31Z mrglavas $
 */
final class PSVIErrorList extends AbstractList implements StringList {

    private final String[] fArray;
    private final int fLength;
    private final int fOffset;
    
    public PSVIErrorList(String[] array, boolean even) {
        fArray = array;
        fLength = (fArray.length >> 1);
        fOffset = even ? 0 : 1;
    }

    public boolean contains(String item) {
        if (item == null) {
            for (int i = 0; i < fLength; ++i) {
                if (fArray[(i << 1) + fOffset] == null) {
                    return true;
                }
            }
        }
        else {
            for (int i = 0; i < fLength; ++i) {
                if (item.equals(fArray[(i << 1) + fOffset])) {
                    return true;
                }
            }
        }
        return false;
    }

    public int getLength() {
        return fLength;
    }

    public String item(int index) {
        if (index < 0 || index >= fLength) {
            return null;
        }
        return fArray[(index << 1) + fOffset];
    }
    
    /*
     * List methods
     */

    public Object get(int index) {
        if (index >= 0 && index < fLength) {
            return fArray[(index << 1) + fOffset];
        }
        throw new IndexOutOfBoundsException("Index: " + index);
    }

    public int size() {
        return getLength();
    }
    
} // class PSVIErrorList
