/*
* 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 15, 2005
*
*/
package org.apache.poi.hssf.record.formula.functions;
import org.apache.poi.hssf.record.formula.eval.BoolEval;
import org.apache.poi.hssf.record.formula.eval.ErrorEval;
import org.apache.poi.hssf.record.formula.eval.Eval;
import org.apache.poi.hssf.record.formula.eval.NumberEval;
import org.apache.poi.hssf.record.formula.eval.RefEval;
import org.apache.poi.hssf.record.formula.eval.StringEval;
import org.apache.poi.hssf.record.formula.eval.ValueEval;
/**
* @author Amol S. Deshmukh < amolweb at ya hoo dot com >
*
*/
public class Left extends TextFunction {
public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
Eval retval = ErrorEval.VALUE_INVALID;
int index = 1;
switch (operands.length) {
default:
break;
case 2:
Eval indexEval = operands[1];
index = evaluateAsInteger(indexEval);
if (index < 0) {
break;
}
case 1:
ValueEval veval = singleOperandEvaluate(operands[0], srcCellRow, srcCellCol);
String str = null;
if (veval instanceof StringEval) {
StringEval stringEval = (StringEval) veval;
str = stringEval.getStringValue();
}
else if (veval instanceof BoolEval) {
BoolEval beval = (BoolEval) veval;
str = beval.getBooleanValue() ? "TRUE" : "FALSE";
}
else if (veval instanceof NumberEval) {
NumberEval neval = (NumberEval) veval;
str = neval.getStringValue();
}
if (null != str) {
str = str.substring(0, Math.min(str.length(), index));
retval = new StringEval(str);
}
}
return retval;
}
protected int evaluateAsInteger(Eval eval) {
int numval = -1;
if (eval instanceof NumberEval) {
NumberEval neval = (NumberEval) eval;
double d = neval.getNumberValue();
numval = (int) d;
}
else if (eval instanceof StringEval) {
StringEval seval = (StringEval) eval;
String s = seval.getStringValue();
try {
double d = Double.parseDouble(s);
numval = (int) d;
}
catch (Exception e) {
}
}
else if (eval instanceof BoolEval) {
BoolEval beval = (BoolEval) eval;
numval = beval.getBooleanValue() ? 1 : 0;
}
else if (eval instanceof RefEval) {
numval = evaluateAsInteger(xlateRefEval((RefEval) eval));
}
return numval;
}
protected Eval xlateRefEval(RefEval reval) {
Eval retval = reval.getInnerValueEval();
if (retval instanceof RefEval) {
retval = xlateRefEval((RefEval) retval);
}
return retval;
}
}