au.gov.tas.dpiwe.mr.util
Class MrRandomList

java.lang.Object
  java.util.AbstractCollection
      java.util.AbstractList
          au.gov.tas.dpiwe.mr.util.MrAbstractList
              au.gov.tas.dpiwe.mr.util.MrRandomList

All Implemented Interfaces:

IterableCollection, Iterable, Collection, List

public class MrRandomList
extends MrAbstractList

An concrete implementation of an AbstractList which can be shuffled and unshuffled. The shuffling only affects the order of iteration, which is guaranteed to be stable every time this list is of the same length. i.e. adding or removing elements will destabilize the iteration order, but restoring the length will result in the same slots being chosen in the same order once more.

Since:

Mr Architecture 3.2

Version:

1.0.0.0

Author:

Kade Hansson, A Warberg

Field Summary

protected Random	r
protected boolean	shuffled

Fields inherited from class au.gov.tas.dpiwe.mr.util.MrAbstractList

l

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

MrRandomList(List elements)
Creates a random list with a particular shuffled order.

MrRandomList(List elements, Random instance)
Creates a random list with a particular shuffled order resulting from the Random instance given.

Method Summary

Object	clone()
Iterator	iterator() Returns the elements in a random order (if in shuffled state) or in natural order (if not in shuffled state).
ListIterator	listIterator() Returns the elements in a random order (if in shuffled state) or in natural order (if not in shuffled state).
static void	main(String[] argv) Run a quick little unit test.
void	reshuffle(long seed) Reshuffles the list.
void	shuffle() Puts the list in shuffled state (the default).
void	unshuffle() Puts the list in unshuffled state.

Methods inherited from class au.gov.tas.dpiwe.mr.util.MrAbstractList

add, get, remove, remove, set, size

Methods inherited from class java.util.AbstractList

add, addAll, clear, equals, hashCode, indexOf, lastIndexOf, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

add, addAll, clear, contains, containsAll, equals, hashCode, isEmpty, removeAll, retainAll, toArray, toArray

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, removeAll, retainAll, toArray, toArray

Field Detail

r

protected Random r

shuffled

protected boolean shuffled

Constructor Detail

MrRandomList

public MrRandomList(List elements)

Creates a random list with a particular shuffled order.

MrRandomList

public MrRandomList(List elements,
                    Random instance)

Creates a random list with a particular shuffled order resulting from the Random instance given.

Parameters:

elements - the list elements.

instance - a source of randomness.

Method Detail

iterator

public Iterator iterator()

Returns the elements in a random order (if in shuffled state) or in natural order (if not in shuffled state).

Specified by:

iterator in interface Iterable

Specified by:

iterator in interface Collection

Specified by:

iterator in interface List

Overrides:

iterator in class AbstractList

Returns:

the appropriately ordered iterator.

listIterator

public ListIterator listIterator()

Returns the elements in a random order (if in shuffled state) or in natural order (if not in shuffled state).

Specified by:

listIterator in interface List

Overrides:

listIterator in class AbstractList

Returns:

the appropriately ordered iterator.

shuffle

public void shuffle()

Puts the list in shuffled state (the default). The shuffled order is unchanged.

reshuffle

public void reshuffle(long seed)

Reshuffles the list. The list is now in shuffled state. System.currentTimeMillis() is suggested as a seed value.

Parameters:

seed - the new seed to shuffle with.

unshuffle

public void unshuffle()

Puts the list in unshuffled state. The shuffled order is retained, and can be restored by calling shuffle(). To get a new shuffled order, call reshuffle().

clone

public Object clone()
             throws CloneNotSupportedException

Overrides:

clone in class MrAbstractList

Throws:

CloneNotSupportedException

main

public static void main(String[] argv)

Run a quick little unit test. Imagine we have a full suit of cards from a standard deck...

Parameters:

argv - no params needed.