edu.kzoo.grid
Class ArrayListGrid.ArrayListGridRep

java.lang.Object
  |
  +--edu.kzoo.grid.ArrayListGrid.ArrayListGridRep

All Implemented Interfaces:

Grid.InternalRepresentation

Enclosing class:

ArrayListGrid

public static class ArrayListGrid.ArrayListGridRep

extends java.lang.Object

implements Grid.InternalRepresentation

Internal representation for an ArrayList-based implementation of a Grid class.

Constructor Summary

protected

ArrayListGrid.ArrayListGridRep(Grid.ValidityChecker checker) Constructs an empty ArrayListGridRep representation of a grid.

Method Summary

void	add(GridObject obj) Adds a new object to this internal grid representation at the location it specifies.
GridObject[]	allObjects() Returns all the objects in this grid.
protected int	indexOf(Location loc) Get the index of the object at the specified location.
boolean	isValid(Location loc) Verifies whether a location is valid in this grid.
int	numObjects() Returns the number of objects in this grid.
GridObject	objectAt(Location loc) Returns the object at a specific location in this grid.
void	remove(GridObject obj) Removes the object from this internal grid representation.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayListGrid.ArrayListGridRep

protected ArrayListGrid.ArrayListGridRep(Grid.ValidityChecker checker)

Constructs an empty ArrayListGridRep representation of a grid.

Parameters:

checker - an object that knows how to check the validity of a location in a grid

Method Detail

isValid

public boolean isValid(Location loc)

Verifies whether a location is valid in this grid.

Specified by:

isValid in interface Grid.InternalRepresentation

Parameters:

loc - location to check

Returns:

true if loc is valid; false otherwise

numObjects

public int numObjects()

Returns the number of objects in this grid.

Specified by:

numObjects in interface Grid.InternalRepresentation

Returns:

the number of objects

allObjects

public GridObject[] allObjects()

Returns all the objects in this grid.

Specified by:

allObjects in interface Grid.InternalRepresentation

Returns:

an array of all the grid objects

objectAt

public GridObject objectAt(Location loc)

Returns the object at a specific location in this grid.

Specified by:

objectAt in interface Grid.InternalRepresentation

Parameters:

loc - the location in which to look

Returns:

the object at location loc; null if loc is not in the grid or is empty

add

public void add(GridObject obj)

Adds a new object to this internal grid representation at the location it specifies. (Precondition: obj.grid() is this grid and obj.location() is a valid empty location; verified by the Grid object.)

Specified by:

add in interface Grid.InternalRepresentation

Parameters:

obj - the new object to be added

remove

public void remove(GridObject obj)

Removes the object from this internal grid representation. (Precondition: obj is in this grid; verified by the Grid object.)

Specified by:

remove in interface Grid.InternalRepresentation

Parameters:

obj - the object to be removed

indexOf

protected int indexOf(Location loc)

Get the index of the object at the specified location.

Parameters:

loc - the location in which to look

Returns:

the index of the object at location loc if there is one; -1 otherwise