/*

 * Copyright 2003 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.swing;

import java.util.*;

/**

 * <b>WARNING:</b> This class is an implementation detail and is only

 * public so that it can be used by two packages. You should NOT consider

 * this public API.

 * <p>

 * <b>WARNING 2:</b> This is not a general purpose List implementation! It

 * has a specific use and will not work correctly if you use it outside of

 * its use.

 * <p>

 * A specialized ArrayList that caches its hashCode as well as overriding

 * equals to avoid creating an Iterator. This class is useful in scenarios

 * where the list won't change and you want to avoid the overhead of hashCode

 * iterating through the elements invoking hashCode. This also assumes you'll

 * only ever compare a BakedArrayList to another BakedArrayList.

 *

 * @author Scott Violet

 */

public class BakedArrayList extends ArrayList {

    /**

     * The cached hashCode.

     */

    private int _hashCode;

    public BakedArrayList(int size) {

        super(size);

    }

    public BakedArrayList(java.util.List data) {

        this(data.size());

        for (int counter = 0, max = data.size(); counter < max; counter++){

            add(data.get(counter));

        }

        cacheHashCode();

    }

    /**

     * Caches the hash code. It is assumed you won't modify the list, or that

     * if you do you'll call cacheHashCode again.

     */

    public void cacheHashCode() {

        _hashCode = 1;

        for (int counter = size() - 1; counter >= 0; counter--) {

            _hashCode = 31 * _hashCode + get(counter).hashCode();

        }

    }

    public int hashCode() {

        return _hashCode;

    }

    public boolean equals(Object o) {

        BakedArrayList list = (BakedArrayList)o;

        int size = size();

        if (list.size() != size) {

            return false;

        }

        while (size-- > 0) {

            if (!get(size).equals(list.get(size))) {

                return false;

            }

        }

        return true;

    }

}