com.collegeboard.gridworld.grid
Interface Grid<E>

All Known Implementing Classes:

BoundedGrid, UnboundedGrid

public interface Grid<E>

Method Summary

E	get(Location loc) Returns the object at a specific location in this grid
ArrayList<Location>	getOccupiedLocations() Gets the locations in this grid that contain objects.
boolean	isValid(Location loc) Checks whether a location is valid in this grid.
int	numCols() Returns number of columns in this grid.
int	numRows() Returns number of rows in this grid.
E	put(Location loc, E obj) Adds a new object to this grid.
E	remove(Location loc) Removes an object from this grid.

Method Detail

numRows

int numRows()

Returns number of rows in this grid.

Returns:

the number of rows, or -1 if the grid is unbounded

numCols

int numCols()

Returns number of columns in this grid.

Returns:

the number of columns, or -1 if the grid is unbounded

put

E put(Location loc,
      E obj)

Adds a new object to this grid.

Parameters:

loc - the location at which to put the object (must be valid)

obj - the new object to be added (must not be null)

Returns:

the object that was removed, or null if the location was previously unoccupied.

remove

E remove(Location loc)

Removes an object from this grid.

Parameters:

loc - the location of the object that is to be removed (must be valid)

Returns:

the object that was removed, or null if no object was in the given location

get

E get(Location loc)

Returns the object at a specific location in this grid

Parameters:

loc - the location in which to look (must be valid)

Returns:

the object at location loc; null if loc is empty

getOccupiedLocations

ArrayList<Location> getOccupiedLocations()

Gets the locations in this grid that contain objects.

Returns:

an array of all occupied locations in this grid

isValid

boolean isValid(Location loc)

Checks whether a location is valid in this grid.

Parameters:

loc - location to check (must not be null)

Returns:

true if loc is valid in this grid; false otherwise