/*
* 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.
*/
/*
 * Created on May 9, 2005
 *
 * 
 */
package org.apache.poi.hssf.record.formula.eval;

/**
 * @author Amol S Deshmukh < amolweb at ya hoo dot com >
 * 
 * RefEval is the super interface for Ref2D and Ref3DEval. Basically a RefEval
 * impl should contain reference to the original ReferencePtg or Ref3DPtg as
 * well as the final "value" resulting from the evaluation of the cell
 * reference. Thus if the HSSFCell has type CELL_TYPE_NUMERIC, the contained
 * value object should be of type NumberEval; if cell type is CELL_TYPE_STRING,
 * contained value object should be of type StringEval
 */
public interface RefEval extends ValueEval {

    /**
     * The (possibly evaluated) ValueEval contained
     * in this RefEval. eg. if cell A1 contains "test"
     * then in a formula referring to cell A1 
     * the RefEval representing
     * A1 will return as the getInnerValueEval() the
     * object of concrete type StringEval
     * @return
     */
    public ValueEval getInnerValueEval();

    /**
     * returns the column index.
     * @return
     */
    public short getColumn();

    /**
     * returns the row index.
     * @return
     */
    public short getRow();
    
    /**
     * returns true if this RefEval contains an
     * evaluated value instead of a direct value.
     * eg. say cell A1 has the value: ="test"
     * Then the RefEval representing A1 will return
     * isEvaluated() equal to false. On the other
     * hand, say cell A1 has the value: =B1 and
     * B1 has the value "test", then the RefEval
     * representing A1 will return isEvaluated()
     * equal to true.
     * @return
     */
    public boolean isEvaluated();

}