AlgoIndexOf.java

/* 
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.GeoList;
import org.geogebra.common.kernel.geos.GeoNumberValue;
import org.geogebra.common.kernel.geos.GeoNumeric;
import org.geogebra.common.kernel.geos.GeoText;

/**
 * Algorithm for searching in text or list
 * 
 * @author Zbynek Konecny
 */
public class AlgoIndexOf extends AlgoElement {

	private GeoElement hayStack; // input
	private GeoElement needle; // input
	private GeoNumeric index; // output
	private GeoNumberValue start;

	/**
	 * Creates new index of algorithm
	 * 
	 * @param cons
	 * @param label
	 * @param needle
	 *            what we want to find
	 * @param hayStack
	 *            GeoList of GeoText in which we want to search
	 */
	public AlgoIndexOf(Construction cons, String label, GeoElement needle,
			GeoElement hayStack) {
		super(cons);

		this.hayStack = hayStack;
		this.needle = needle;

		index = new GeoNumeric(cons);

		setInputOutput();
		compute();
		index.setLabel(label);
	}

	/**
	 * Creates new index of algorithm
	 * 
	 * @param cons
	 * @param label
	 * @param needle
	 *            what we want to find
	 * @param hayStack
	 *            GeoList of GeoText in which we want to search
	 * @param start
	 *            start index (1 means "search from beginning")
	 */
	public AlgoIndexOf(Construction cons, String label, GeoElement needle,
			GeoElement hayStack, GeoNumberValue start) {
		super(cons);

		this.hayStack = hayStack;
		this.needle = needle;
		this.start = start;
		index = new GeoNumeric(cons);

		setInputOutput();
		compute();
		index.setLabel(label);
	}

	@Override
	public Commands getClassName() {
		return Commands.IndexOf;
	}

	@Override
	protected void setInputOutput() {
		if (start == null) {
			input = new GeoElement[2];
			input[0] = needle;
			input[1] = hayStack;

		} else {
			input = new GeoElement[3];
			input[0] = needle;
			input[1] = hayStack;
			input[2] = start.toGeoElement();
		}

		setOutputLength(1);
		setOutput(0, index);
		setDependencies(); // done by AlgoElement
	}

	/**
	 * Returns the resulting index
	 * 
	 * @return the resulting index
	 */
	public GeoNumeric getResult() {
		return index;
	}

	@Override
	public final void compute() {

		index.setUndefined();

		int startAt = start != null ? (int) start.getDouble() - 1 : 0;

		if (startAt < 0) {
			return;
		}

		if (hayStack.isGeoText()) {
			// undefined haystack <=> getTextString is null
			if (((GeoText) hayStack).getTextString() == null) {
				index.setUndefined();
				return;
			}
			int pos = ((GeoText) hayStack).getTextString()
					.indexOf(((GeoText) needle).getTextString(), startAt);
			if (pos > -1) {
				index.setValue(pos + 1);
			}
			return;
		}
		int size = ((GeoList) hayStack).size();
		for (int i = startAt; i < size; i++) {
			GeoElement cmp = ((GeoList) hayStack).get(i);
			if (needle.isEqual(cmp)) {
				index.setValue(i + 1);
				break;
			}
		}
	}

}