info.gridworld.grid
Interface Grid<E>

All Known Implementing Classes:

AbstractGrid, BoundedGrid, UnboundedGrid

public interface Grid<E>

Grid provides an interface for a two-dimensional, grid-like environment containing arbitrary objects.
This interface is testable on the AP CS A and AB exams.

Method Summary

E	get(Location loc) Returns the object at a given location in this grid.
ArrayList<Location>	getEmptyAdjacentLocations(Location loc) Gets the valid empty locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
ArrayList<E>	getNeighbors(Location loc) Gets the neighboring occupants in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
ArrayList<E>	getOccupants() Gets the occupants in all locations in this grid.
int	getNumCols() Returns the number of columns in this grid.
int	getNumRows() Returns the number of rows in this grid.
ArrayList<Location>	getOccupiedAdjacentLocations(Location loc) Gets the valid occupied locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
ArrayList<Location>	getOccupiedLocations() Gets the locations in this grid that contain objects.
ArrayList<Location>	getValidAdjacentLocations(Location loc) Gets the valid locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
boolean	isValid(Location loc) Checks whether a location is valid in this grid.
boolean	isEmpty(Location loc) Checks whether a location is valid and empty in this grid.
E	put(Location loc, E obj) Puts an object at a given location in this grid.
E	remove(Location loc) Removes the object at a given location from this grid.

Method Detail

getNumRows

int getNumRows()

Returns the number of rows in this grid.

Returns:

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

getNumCols

int getNumCols()

Returns the number of columns in this grid.

Returns:

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

isValid

boolean isValid(Location loc)

Checks whether a location is valid in this grid.
Precondition: loc is not null

Parameters:

loc - the location to check

Returns:

true if loc is valid in this grid, false otherwise

isEmpty

boolean isEmpty(Location loc)

Checks whether a location is valid and empty in this grid.
Precondition: loc is not null

Parameters:

loc - the location to check

Returns:

true if loc is valid and empty in this grid, false otherwise

put

E put(Location loc,
      E obj)

Puts an object at a given location in this grid.
Precondition: (1) loc is valid in this grid (2) obj is not null

Parameters:

loc - the location at which to put the object

obj - the new object to be added

Returns:

the object previously at loc (or null if the location was previously unoccupied)

remove

E remove(Location loc)

Removes the object at a given location from this grid.
Precondition: loc is valid in this grid

Parameters:

loc - the location of the object that is to be removed

Returns:

the object that was removed (or null if the location is unoccupied)

get

E get(Location loc)

Returns the object at a given location in this grid.
Precondition: loc is valid in this grid

Parameters:

loc - a location in this grid

Returns:

the object at location loc (or null if the location is unoccupied)

getOccupiedLocations

ArrayList<Location> getOccupiedLocations()

Gets the locations in this grid that contain objects.

Returns:

an array list of all occupied locations in this grid

getValidAdjacentLocations

ArrayList<Location> getValidAdjacentLocations(Location loc)

Gets the valid locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
Precondition: loc is valid in this grid

Parameters:

loc - a location in this grid

Returns:

an array list of the valid locations adjacent to loc in this grid

getEmptyAdjacentLocations

ArrayList<Location> getEmptyAdjacentLocations(Location loc)

Gets the valid empty locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
Precondition: loc is valid in this grid

Parameters:

loc - a location in this grid

Returns:

an array list of the valid empty locations adjacent to loc in this grid

getOccupiedAdjacentLocations

ArrayList<Location> getOccupiedAdjacentLocations(Location loc)

Gets the valid occupied locations adjacent to a given location in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
Precondition: loc is valid in this grid

Parameters:

loc - a location in this grid

Returns:

an array list of the valid occupied locations adjacent to locÂ in this grid

getOccupants

ArrayList<E> getOccupants()

Gets all occupants in this grid.

Parameters:

loc - a location in this grid

Returns:

returns an array list of the objects in all occupied locations

getNeighbors

ArrayList<E> getNeighbors(Location loc)

Gets the neighboring occupants in all eight compass directions (north, northeast, east, southeast, south, southwest, west, and northwest).
Precondition: loc is valid in this grid

Parameters:

loc - a location in this grid

Returns:

returns an array list of the objects in the occupied locations adjacent to loc in this grid