core
Class Piece

java.lang.Object
  core.Piece

Direct Known Subclasses:

King, Knight, NoneSquare, Pawn, StraightPiece

public abstract class Piece
extends Object

A Piece represents a state of the board. Individual pieces are subclasses of Piece, overriding various methods to determine their name and how they move. Pieces are immutable. One special case is Empty, for non-piece squares.

Specification Fields

• state : int //Useful for castling/en passant
• color : Color //Who the owner is
• name : String //Name of this piece type

Derived Fields:

moves(GameState) : Set //Possible moves from a position

Field Summary

protected Color

color

Constructor Summary

Piece(Color color, int lastMove)
Constructs a new piece.

Method Summary

Color	getColor()
int	getLastMove()
protected abstract String	getName()
abstract int	hashCode() This should be unique for different pieces or different colors.
abstract Collection<Move>	moveCandidates(GameState g, Position here)
abstract String	pieceString()
void	postMove(GameState gs, Map<Position,Piece> move, Position here) Apply the modifications to a move map for a move onto this square completes.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

color

protected Color color

Constructor Detail

Piece

public Piece(Color color,
             int lastMove)

Constructs a new piece.

Parameters:

color - of the piece

lastMove - of the piece (0 means it hasn't moved)

Requires:

color not null, last move valid

Method Detail

getName

protected abstract String getName()

Returns:

a single-character name of this piece

pieceString

public abstract String pieceString()

Returns:

a human readable string for the piece.

moveCandidates

public abstract Collection<Move> moveCandidates(GameState g,
                                                Position here)

Requires:

g, here != null

Returns:

valid moves for this piece.

getLastMove

public int getLastMove()

Returns:

the last time this piece moved

getColor

public Color getColor()

Returns:

the color of this piece

toString

public String toString()

Overrides:

toString in class Object

Returns:

the short 1-character name of this piece, in lower case for black and upper case for white.

postMove

public void postMove(GameState gs,
                     Map<Position,Piece> move,
                     Position here)

Apply the modifications to a move map for a move onto this square completes. Used to implement powerups; others can safely do nothing.

hashCode

public abstract int hashCode()

This should be unique for different pieces or different colors.

Overrides:

hashCode in class Object