/*
GeoGebra - Dynamic Mathematics for Everyone
http://www.geogebra.org
This file is part of GeoGebra.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation.
*/
package org.geogebra.common.kernel.advanced;
import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.algos.AlgoElement;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoElement;
import org.geogebra.common.kernel.geos.GeoNumberValue;
import org.geogebra.common.kernel.geos.GeoText;
/**
* n-th element of a GeoList object.
*
* Note: the type of the returned GeoElement object is determined by the type of
* the first list element. If the list is initially empty, a GeoNumeric object
* is created for element.
*
* @author Michael
* @version 20100205
*/
public class AlgoTextElement extends AlgoElement {
private GeoText text; // input
private GeoNumberValue num = null; // input
private GeoElement numGeo;
private GeoText textOut; // output
/**
* @param cons
* construction
* @param label
* output label
* @param text
* input text
* @param num
* index
*/
public AlgoTextElement(Construction cons, String label, GeoText text,
GeoNumberValue num) {
super(cons);
this.text = text;
this.num = num;
numGeo = num.toGeoElement();
textOut = new GeoText(cons);
textOut.setIsTextCommand(true);
setInputOutput();
compute();
textOut.setLabel(label);
}
@Override
public Commands getClassName() {
return Commands.Element;
}
@Override
protected void setInputOutput() {
input = new GeoElement[2];
input[0] = text;
input[1] = numGeo;
super.setOutputLength(1);
super.setOutput(0, textOut);
setDependencies(); // done by AlgoElement
}
/**
* @return result
*/
public GeoText getText() {
return textOut;
}
@Override
public final void compute() {
if (!numGeo.isDefined() || !text.isDefined()) {
textOut.setUndefined();
return;
}
String str = text.getTextString();
int n = (int) num.getNumber().getDouble();
if (n < 1 || n > str.length()) {
textOut.setUndefined();
} else {
textOut.setTextString(str.charAt(n - 1) + "");
}
}
}