package org.junit.runner.manipulation;

import java.util.Comparator;

import org.junit.runner.Description;

import org.junit.runner.Runner;

/**

 * A <code>Sorter</code> orders tests. In general you will not need

 * to use a <code>Sorter</code> directly. Instead, use {@link org.junit.runner.Request#sortWith(Comparator)}.

 * 

 * 

 */

public class Sorter implements Comparator<Description> {

	private final Comparator<Description> fComparator;

	/**

	 * Creates a <code>Sorter</code> that uses <code>comparator</code>

	 * to sort tests

	 * @param comparator the {@link Comparator} to use when sorting tests

	 */

	public Sorter(Comparator<Description> comparator) {

		fComparator= comparator;

	}

	/**

	 * Sorts the test in <code>runner</code> using <code>comparator</code>

	 * @param runner

	 */

	public void apply(Runner runner) {

		if (runner instanceof Sortable) {

			Sortable sortable = (Sortable) runner;

			sortable.sort(this);

		}

	}

	/** @inheritDoc */

	public int compare(Description o1, Description o2) {

		return fComparator.compare(o1, o2);

	}

}