org.ascape.model.space
Class Singleton

java.lang.Object
  org.ascape.model.space.CollectionSpace
      org.ascape.model.space.Singleton

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Iterable, java.util.Collection, Space, RandomFunctions

public class Singleton
extends CollectionSpace

A space with treates itself as its only member. This provides agents with a way to have single rules implemented upon them and to support views.

Since:

1.0

Version:

3.0

Author:

Miles Parker

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.ascape.model.space.CollectionSpace

CollectionSpace.ClosestDataPoint, CollectionSpace.ConditionalIterator, CollectionSpace.CSIterator, CollectionSpace.CSMutableIterator, CollectionSpace.ListMutableRandomIterator, CollectionSpace.ListRandomIterator, CollectionSpace.MutableSubIterator, CollectionSpace.SubIterator

Field Summary

Fields inherited from class org.ascape.model.space.CollectionSpace

collection, ESTIMATED_MAXIMUM_SIZE, extent, geometry

Constructor Summary

Singleton()
Construct a new Singleton.

Method Summary

double	calculateDistance(Coordinate origin, Coordinate target) Returns the shortest distance between one agent and another.
void	construct() Normally, create the basic strucutre of the space.
Location	findRandom() Returns an agent randomly selected from the collection.
Coordinate	findRandomCoordinate() Returns a coordinate randomly selected from the collection's space.
Location[]	getLocations() Returns all agents in the space as an array.
int	getSize() Returns the number of members of this space.
boolean	isMutable() Is the context mutable, that is, can it change its structure at runtime? Returns true for this collection.
java.util.Iterator	iterator() Returns an iterator across all agents in this context.
void	moveAway(Location origin, Coordinate target, double distance) Moves an agent toward the specified agent.
void	moveToward(Location origin, Coordinate target, double distance) Moves an agent toward the specified agent.
void	populate() Normally, populates the space with instances of its protoype agent.
ResetableIterator	safeIterator() Returns a context iterator across all objects in this context.
ResetableIterator	safeIterator(int start, int limit) Safe iterator.
RandomIterator	safeRandomIterator() Returns a context iterator across all agents in random order.
void	setExtent(Coordinate extent) Sets the size of the context.
java.lang.String	toString() Returns a string representing this space.

Methods inherited from class org.ascape.model.space.CollectionSpace

add, add, addAll, calculateDistance, clear, clone, conditionalIterator, conditionalIterator, contains, containsAll, countWithin, createOrder, createSpatialConditional, deleteSweep, filter, find, findMaximum, findMaximum, findMaximumWithin, findMinimum, findMinimum, findMinimumWithin, findNearest, findNearest, findRandom, findRandom, findRandom, findRandomWithin, findWithin, get, getContext, getExtent, getGeometry, getRandom, hasWithin, initialize, isDeleteSweepNeeded, isEmpty, isPeriodic, iteratorCount, iteratorToList, newLocation, newLocation, randomInRange, randomInRange, randomIs, randomizeOrder, randomToLimit, remove, removeAll, retainAll, safeIterators, set, setContext, setExtent, setGeometry, setPeriodic, setRandom, setSize, size, toArray, toArray, toList, withinIterator

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

Singleton

public Singleton()

Construct a new Singleton.

Method Detail

getSize

public int getSize()

Returns the number of members of this space.

Specified by:

getSize in interface Space

Overrides:

getSize in class CollectionSpace

Returns:

the size

construct

public void construct()

Normally, create the basic strucutre of the space. Here, a noop, since the space member is the space itself.

Specified by:

construct in interface Space

Overrides:

construct in class CollectionSpace

populate

public void populate()

Normally, populates the space with instances of its protoype agent. Here, a noop, since the space member is the space itself.

Specified by:

populate in interface Space

Overrides:

populate in class CollectionSpace

iterator

public java.util.Iterator iterator()

Description copied from class: CollectionSpace

Returns an iterator across all agents in this context. Note that this is simply an iterator of the backing collections members. It will have different behavior than is typically desried when iterating behavior across a context*; so for instance, this method is not used by the internal rule mechanism. It should be perfectly adequete for tight iterations across agents when there are no additions or deletions during the iteration; for instance, when calcualting some value across a number of agents. *The iterator will not be aware of an agents deletion from the context after its creation; this is because the context caches these removals to improve performance. It may include agents that are added to the context after its creation, and this is typically not desirable behavior when touring a collection of current agents.

Specified by:

iterator in interface java.lang.Iterable

Specified by:

iterator in interface java.util.Collection

Overrides:

iterator in class CollectionSpace

Returns:

an iterator over the agents in context order

safeIterator

public ResetableIterator safeIterator(int start,
                                      int limit)

Description copied from interface: Space

Safe iterator.

Specified by:

safeIterator in interface Space

Overrides:

safeIterator in class CollectionSpace

Parameters:

start - the start

limit - the limit

Returns:

the resetable iterator

safeIterator

public ResetableIterator safeIterator()

Description copied from class: CollectionSpace

Returns a context iterator across all objects in this context. This iterator differs from a collection iterator in two fundamental ways. First, it handles deletions and adds differently. It does not include any objects that are added after the iterator has been created, and it correctly deals with the case where agents are removed from the context after the creation of the iterator. (As such deletions are marked for a later delete sweep, but not actually removed the iterator has to be aware of them.) Second, it allows these deletions to occur after an iteration has been created, without throwing a ConcurrentModificationExcpetion on a next (or similar) call. Such modifications (say during the execution of fission or death behaviors) during a particular behavior are expected. The important thing is that objects that have been removed from a context do not have rules executed upon them, and that new agents added to a context do not have behavior executed on them in the current iteration. This iterator ensures that.

Specified by:

safeIterator in interface Space

Overrides:

safeIterator in class CollectionSpace

Returns:

an iterator over the agents in context order

safeRandomIterator

public RandomIterator safeRandomIterator()

Description copied from class: CollectionSpace

Returns a context iterator across all agents in random order. Other than its random order, it has identical behavior to context iterator; see the important notes for that method.

Specified by:

safeRandomIterator in interface Space

Overrides:

safeRandomIterator in class CollectionSpace

Returns:

an iterator over the agents in context order

getLocations

public Location[] getLocations()

Returns all agents in the space as an array.

Returns:

the locations

moveToward

public void moveToward(Location origin,
                       Coordinate target,
                       double distance)

Moves an agent toward the specified agent.

Specified by:

moveToward in interface Space

Overrides:

moveToward in class CollectionSpace

Parameters:

origin - the agent moving

target - the agent's target

distance - the distance to move

moveAway

public void moveAway(Location origin,
                     Coordinate target,
                     double distance)

Moves an agent toward the specified agent.

Specified by:

moveAway in interface Space

Overrides:

moveAway in class CollectionSpace

Parameters:

origin - the agent moving

target - the agent's target

distance - the distance to move

calculateDistance

public double calculateDistance(Coordinate origin,
                                Coordinate target)

Returns the shortest distance between one agent and another. In this case, must be 0.

Specified by:

calculateDistance in interface Space

Overrides:

calculateDistance in class CollectionSpace

Parameters:

origin - the starting cell

target - the ending cell

Returns:

the double

toString

public java.lang.String toString()

Returns a string representing this space.

Overrides:

toString in class java.lang.Object

Returns:

the string

findRandom

public Location findRandom()

Description copied from class: CollectionSpace

Returns an agent randomly selected from the collection. If no agents exist, returns null.

Specified by:

findRandom in interface Space

Overrides:

findRandom in class CollectionSpace

Returns:

the location

findRandomCoordinate

public Coordinate findRandomCoordinate()

Description copied from class: CollectionSpace

Returns a coordinate randomly selected from the collection's space.

Specified by:

findRandomCoordinate in interface Space

Overrides:

findRandomCoordinate in class CollectionSpace

Returns:

the coordinate

setExtent

public void setExtent(Coordinate extent)

Description copied from class: CollectionSpace

Sets the size of the context. Note that context graphs will not have useful extents, but all other scapes do. It is an error to set extent while a context is running.

Specified by:

setExtent in interface Space

Overrides:

setExtent in class CollectionSpace

Parameters:

extent - a coordinate at the maximum extent

isMutable

public final boolean isMutable()

Description copied from class: CollectionSpace

Is the context mutable, that is, can it change its structure at runtime? Returns true for this collection.

Specified by:

isMutable in interface Space

Overrides:

isMutable in class CollectionSpace

Returns:

true, if is mutable