/*
* RandomOrderIterator.java
*
* Copyright 2009 Andres Quiroz Hernandez
*
* This file is part of Programming5.
* Programming5 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.
*
* Programming5 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 Programming5. If not, see <http://www.gnu.org/licenses/>.
*
*/
package programming5.collections;
import java.util.Collection;
import java.util.Iterator;
import programming5.arrays.RandomOrderGenerator;
/**
* This class allows the traversal of a given collection in random order. Modifications to the collection will not be reflected in the objects returned
* @author Andres
* @version 6.0
*/
public class RandomOrderIterator<T> implements Iterator<T> {
protected Object[] array;
protected RandomOrderGenerator rog;
private int count = 0;
/**
*Creates an iterator object to randomly traverse the given collection (can be traversed cyclically, in a new order each time)
*/
public RandomOrderIterator(Collection<T> myCollection) {
array = myCollection.toArray();
rog = new RandomOrderGenerator();
rog.generate(array.length);
}
/**
*Creates an iterator object to randomly traverse the given collection (can be traversed cyclically, in a new order each time) using the given seed for the random order generator
*/
public RandomOrderIterator(Collection<T> myCollection, long seed) {
array = myCollection.toArray();
rog = new RandomOrderGenerator(seed);
rog.generate(array.length);
}
/**
*@return false once all of the elements of the collection have been traversed; is reset if next is called to start a new traversal
*/
public boolean hasNext() {
return (count != array.length);
}
/**
*@return a randomly chosen element of the collection that has not been traversed in the current order
*/
public T next() {
count++;
if (count > array.length) {
rog.generate(array.length);
count = 1;
}
return (T) array[rog.nextIndex()];
}
/**
*Method not supported by this implementation
*/
public void remove() {
throw new UnsupportedOperationException();
}
}