Strand.java

/*******************************************************************************
 * GenPlay, Einstein Genome Analyzer
 * Copyright (C) 2009, 2014 Albert Einstein College of Medicine
 * 
 * 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, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * Authors: Julien Lajugie <julien.lajugie@einstein.yu.edu>
 *          Nicolas Fourel <nicolas.fourel@einstein.yu.edu>
 *          Eric Bouhassira <eric.bouhassira@einstein.yu.edu>
 * 
 * Website: <http://genplay.einstein.yu.edu>
 ******************************************************************************/
package edu.yu.einstein.genplay.dataStructure.enums;

import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;

/**
 * @author Julien Lajugie
 * @version 0.1
 * The Strand class represents a strand.
 */
public enum Strand {
	/**
	 * 5' strand
	 */
	FIVE ('+', 'F'),
	/**
	 * 3' strand
	 */
	THREE ('-', 'R');


	private final char 							symbol1;		// symbol representing the strand (+ or -)
	private final char 							symbol2;		// symbol representing the strand (F or R)
	private static final Map<Character, Strand> LOOKUP1 =
			new HashMap<Character, Strand>();						// Map associating the Strand symbol 1 to a Strand
	private static final Map<Character, Strand> LOOKUP2 =
			new HashMap<Character, Strand>();						// Map associating the Strand symbol 2 to a Strand


	/**
	 * Fills the Map with all the different values of Strand
	 */
	static {
		for(Strand s : EnumSet.allOf(Strand.class)) {
			LOOKUP1.put(s.symbol1, s);
			LOOKUP2.put(s.symbol2, s);
		}
	}


	/**
	 * @param strandSymbol '+' or '-' or 'F' or 'R'
	 * @return the {@link Strand} associated to the parameter. Null if none.
	 */
	public static Strand get(char strandSymbol) {
		Strand result = LOOKUP1.get(strandSymbol);
		if (result != null) {
			return result;
		} else {
			return LOOKUP2.get(strandSymbol);
		}
	}


	/**
	 * Private constructor. Creates an instance of {@link Strand}
	 * @param symbol1 character representing the strand (+ or -)
	 * @param symbol2 character representing the strand (F or R)
	 */
	private Strand(char symbol1, char symbol2) {
		this.symbol1 = symbol1;
		this.symbol2 = symbol2;
	}


	/**
	 * @return "+" for strand 5', "-" for strand 3'.
	 */
	@Override
	public String toString(){
		return Character.toString(symbol1);
	}
}