/*

 */

/*

 * 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.xerces.internal.impl.xs.util;

import java.lang.reflect.Array;

import java.util.AbstractList;

import java.util.Iterator;

import java.util.ListIterator;

import java.util.NoSuchElementException;

/**

 * Containts a list of XSObject's.

 *

 * @xerces.internal

 *

 * @author Sandy Gao, IBM

 *

 */

    /**

     * An immutable empty list.

     */

    public static final XSObjectListImpl EMPTY_LIST = new XSObjectListImpl(new XSObject[0], 0);

        public boolean hasNext() {

            return false;

        }

            throw new NoSuchElementException();

        }

        public boolean hasPrevious() {

            return false;

        }

            throw new NoSuchElementException();

        }

        public int nextIndex() {

            return 0;

        }

        public int previousIndex() {

            return -1;

        }

        public void remove() {

            throw new UnsupportedOperationException();

        }

            throw new UnsupportedOperationException();

        }

            throw new UnsupportedOperationException();

        }

    private static final int DEFAULT_SIZE = 4;

    // The array to hold all data

    private XSObject[] fArray = null;

    // Number of elements in this list

    private int fLength = 0;

    public XSObjectListImpl() {

        fArray = new XSObject[DEFAULT_SIZE];

        fLength = 0;

    }

    /**

     * Construct an XSObjectList implementation

     *

     * @param array     the data array

     * @param length    the number of elements

     */

    public XSObjectListImpl(XSObject[] array, int length) {

        fArray = array;

        fLength = length;

    }

    /**

     * The number of <code>XSObjects</code> in the list. The range of valid

     * child node indices is 0 to <code>length-1</code> inclusive.

     */

    public int getLength() {

        return fLength;

    }

    /**

     * Returns the <code>index</code>th item in the collection. The index

     * starts at 0. If <code>index</code> is greater than or equal to the

     * number of nodes in the list, this returns <code>null</code>.

     * @param index index into the collection.

     * @return The XSObject at the <code>index</code>th position in the

     *   <code>XSObjectList</code>, or <code>null</code> if that is not a

     *   valid index.

     */

    public XSObject item(int index) {

        if (index < 0 || index >= fLength) {

            return null;

        }

        return fArray[index];

    }

    // clear this object

    public void clearXSObjectList() {

        for (int i=0; i<fLength; i++) {

            fArray[i] = null;

        }

        fArray = null;

        fLength = 0;

    }

    public void addXSObject(XSObject object) {

       if (fLength == fArray.length) {

           XSObject[] temp = new XSObject[fLength + 4];

           System.arraycopy(fArray, 0, temp, 0, fLength);

           fArray = temp;

       }

       fArray[fLength++] = object;

    }

    public void addXSObject(int index, XSObject object) {

        fArray[index] = object;

    }

    /*

     * List methods

     */

    public boolean contains(Object value) {

        return (value == null) ? containsNull() : containsObject(value);

    }

        if (index >= 0 && index < fLength) {

            return fArray[index];

        }

        throw new IndexOutOfBoundsException("Index: " + index);

    }

    public int size() {

        return getLength();

    }

        return listIterator0(0);

    }

        return listIterator0(0);

    }

        if (index >= 0 && index < fLength) {

            return listIterator0(index);

        }

        throw new IndexOutOfBoundsException("Index: " + index);

    }

        return fLength == 0 ? EMPTY_ITERATOR : new XSObjectListIterator(index);

    }

    private boolean containsObject(Object value) {

        for (int i = fLength - 1; i >= 0; --i) {

            if (value.equals(fArray[i])) {

                return true;

            }

        }

        return false;

    }

    private boolean containsNull() {

        for (int i = fLength - 1; i >= 0; --i) {

            if (fArray[i] == null) {

                return true;

            }

        }

        return false;

    }

    public Object[] toArray() {

        Object[] a = new Object[fLength];

        toArray0(a);

        return a;

    }

    public Object[] toArray(Object[] a) {

        if (a.length < fLength) {

            a = (Object[]) Array.newInstance(componentType, fLength);

        }

        toArray0(a);

        if (a.length > fLength) {

            a[fLength] = null;

        }

        return a;

    }

    private void toArray0(Object[] a) {

        if (fLength > 0) {

            System.arraycopy(fArray, 0, a, 0, fLength);

        }

    }

        private int index;

        public XSObjectListIterator(int index) {

            this.index = index;

        }

        public boolean hasNext() {

            return (index < fLength);

        }

            if (index < fLength) {

                return fArray[index++];

            }

            throw new NoSuchElementException();

        }

        public boolean hasPrevious() {

            return (index > 0);

        }

            if (index > 0) {

                return fArray[--index];

            }

            throw new NoSuchElementException();

        }

        public int nextIndex() {

            return index;

        }

        public int previousIndex() {

            return index - 1;

        }

        public void remove() {

            throw new UnsupportedOperationException();

        }

            throw new UnsupportedOperationException();

        }

            throw new UnsupportedOperationException();

        }

    }

} // class XSObjectListImpl