OrderByItem.java

/**************************************************************************************
 * Copyright (C) 2008 EsperTech, Inc. All rights reserved.                            *
 * http://esper.codehaus.org                                                          *
 * http://www.espertech.com                                                           *
 * ---------------------------------------------------------------------------------- *
 * The software in this package is published under the terms of the GPL license       *
 * a copy of which has been included with this distribution in the license.txt file.  *
 **************************************************************************************/
package com.espertech.esper.epl.spec;

import com.espertech.esper.epl.expression.ExprNode;
import com.espertech.esper.util.MetaDefItem;

import java.io.Serializable;

/**
 * Specification object to an element in the order-by expression.
 */
public class OrderByItem implements MetaDefItem, Serializable
{
    private ExprNode exprNode;
    private boolean isDescending;
    private static final long serialVersionUID = 4147598689501964350L;

    /**
     * Ctor.
     * @param exprNode is the order-by expression node
     * @param ascending is true for ascending, or false for descending sort
     */
    public OrderByItem(ExprNode exprNode, boolean ascending)
    {
        this.exprNode = exprNode;
        isDescending = ascending;
    }

    /**
     * Returns the order-by expression node.
     * @return expression node.
     */
    public ExprNode getExprNode()
    {
        return exprNode;
    }

    /**
     * Returns true for ascending, false for descending.
     * @return indicator if ascending or descending
     */
    public boolean isDescending()
    {
        return isDescending;
    }

    public OrderByItem copy() {
        return new OrderByItem(exprNode, isDescending());
    }
}