pt.ua.gboard.games
Class ChessBoard

java.lang.Object
  pt.ua.gboard.games.ChessBoard

public class ChessBoard
extends java.lang.Object

A GBoard based chess board.

Board coordinates can use a pair of integers or a classical chess String position.
Top-left coordinate is (0,0) or AN (N is the board's dimension).

invariant: N >= 1
invariant: board != null

This class follows DbC(tm) methodology. Where possible, contracts are implement with JML and native's Java assert.

Author:

Miguel Oliveira e Silva (mos@ua.pt)

Field Summary

GBoard	board Maze's GBoard object.
int	N Board dimensions.
ChessPieces	pieces Chess pieces.

Constructor Summary

ChessBoard(int N)
Creates a NxN chess board.

Method Summary

void	clear() Empties the board.
int	column(java.lang.String pos) Converts a String position coordinate to a column number;
boolean	emptyPosition(int line, int column) Is position (line,column) empty?
boolean	emptyPosition(java.lang.String pos) Is position pos empty?
ChessPiece	get(int line, int column) Observe a chess piece in the board.
ChessPiece	get(java.lang.String pos) Observe a chess piece in the board.
void	initializeChessGame() Initializes a standard 8x8 chess board.
int	line(java.lang.String pos) Converts a String position coordinate to a line number;
void	move(int fromLine, int fromColumn, int toLine, int toColumn) Moves a chess piece inside the board.
void	move(java.lang.String fromPos, java.lang.String toPos) Moves a chess piece inside the board.
java.lang.String[]	piecePositions(ChessPieceType piece) Returns an array with the positions of a piece.
boolean	positionSelected(int line, int column) Is position (line,column) selected?
boolean	positionSelected(java.lang.String pos) Is position pos selected?
void	put(ChessPiece piece, int line, int column) Puts a chess piece in the board.
void	put(ChessPiece piece, java.lang.String pos) Puts a chess piece in the board.
void	put(ChessPieceType piece, int line, int column) Puts a chess piece in the board.
void	put(ChessPieceType piece, java.lang.String pos) Puts a chess piece in the board.
void	remove(int line, int column) Removes a chess piece from the board.
void	remove(java.lang.String pos) Removes a chess piece from the board.
void	selectPosition(int line, int column) Select position (line,column).
void	selectPosition(java.lang.String pos) Select position pos.
java.lang.String	toPosition(int line, int column) Converts integer position coordinates to a String position.
void	unselectPosition(int line, int column) Unselect position (line,column).
void	unselectPosition(java.lang.String pos) Unelect position pos.
boolean	validPosition(int line, int column) Is (line,column) a valid board position?
boolean	validPosition(java.lang.String pos) Is pos a valid board position?

Methods inherited from class java.lang.Object

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

Field Detail

N

public final int N

Board dimensions.

board

public final GBoard board

Maze's GBoard object.

pieces

public final ChessPieces pieces

Chess pieces.

Constructor Detail

ChessBoard

public ChessBoard(int N)

Creates a NxN chess board.

requires: N > 0

Parameters:

N - board dimensions

Method Detail

initializeChessGame

public void initializeChessGame()

Initializes a standard 8x8 chess board.

requires: N == 8

clear

public void clear()

Empties the board.

validPosition

public boolean validPosition(int line,
                             int column)

Is (line,column) a valid board position?

Parameters:

line - line number

column - column number

Returns:

boolean true if position is valid, otherwise it returns false

validPosition

public boolean validPosition(java.lang.String pos)

Is pos a valid board position?

Parameters:

pos - position text

Returns:

boolean true if position is valid, false otherwise

toPosition

public java.lang.String toPosition(int line,
                                   int column)

Converts integer position coordinates to a String position.

requires: validPosition(line, column)

ensures: validPosition(\result)

Parameters:

line - line number

column - column number

Returns:

String position text

line

public int line(java.lang.String pos)

Converts a String position coordinate to a line number;

requires: validPosition(pos)

ensures: \result >= 0 && \result < N

Parameters:

pos - position text

Returns:

int line number

column

public int column(java.lang.String pos)

Converts a String position coordinate to a column number;

requires: validPosition(pos)

ensures: \result >= 0 && \result < N

Parameters:

pos - position text

Returns:

int column number

emptyPosition

public boolean emptyPosition(int line,
                             int column)

Is position (line,column) empty?

requires: validPosition(line, column)

Parameters:

line - line number

column - column number

Returns:

boolean true if position is empty, otherwise it returns false

emptyPosition

public boolean emptyPosition(java.lang.String pos)

Is position pos empty?

requires: validPosition(pos)

Parameters:

pos - position text

Returns:

boolean true if position is empty, otherwise it returns false

put

public void put(ChessPieceType piece,
                int line,
                int column)

Puts a chess piece in the board.

requires: emptyPosition(line, column)

ensures: !emptyPosition(line, column)

Parameters:

piece - chess piece type

line - line number

column - column number

put

public void put(ChessPieceType piece,
                java.lang.String pos)

Puts a chess piece in the board.

requires: emptyPosition(pos)

ensures: !emptyPosition(pos)

Parameters:

piece - chess piece type

pos - position text

put

public void put(ChessPiece piece,
                int line,
                int column)

Puts a chess piece in the board.

requires: emptyPosition(line, column)

ensures: !emptyPosition(line, column)

Parameters:

piece - chess piece type

line - line number

column - column number

put

public void put(ChessPiece piece,
                java.lang.String pos)

Puts a chess piece in the board.

requires: emptyPosition(pos)

ensures: !emptyPosition(pos)

Parameters:

piece - chess piece type

pos - position text

get

public ChessPiece get(int line,
                      int column)

Observe a chess piece in the board.

requires: !emptyPosition(line, column)

Parameters:

line - line number

column - column number

Returns:

ChessPiece chess piece

get

public ChessPiece get(java.lang.String pos)

Observe a chess piece in the board.

requires: !emptyPosition(pos)

Parameters:

pos - position text

Returns:

ChessPiece chess piece

remove

public void remove(int line,
                   int column)

Removes a chess piece from the board.

requires: !emptyPosition(line, column)

ensures: emptyPosition(line, column)

Parameters:

line - line number

column - column number

remove

public void remove(java.lang.String pos)

Removes a chess piece from the board.

requires: !emptyPosition(pos)

ensures: emptyPosition(pos)

Parameters:

pos - position text

piecePositions

public java.lang.String[] piecePositions(ChessPieceType piece)

Returns an array with the positions of a piece.

Parameters:

piece - piece type

Returns:

String[] the positions array

move

public void move(int fromLine,
                 int fromColumn,
                 int toLine,
                 int toColumn)

Moves a chess piece inside the board.

requires: !emptyPosition(fromLine, fromColumn)
requires: emptyPosition(toLine, toColumn)

ensures: emptyPosition(fromLine, fromColumn)
ensures: !emptyPosition(toLine, toColumn)

Parameters:

fromLine - source line number

fromColumn - source column number

toLine - destination line number

toColumn - destination column number

move

public void move(java.lang.String fromPos,
                 java.lang.String toPos)

Moves a chess piece inside the board.

requires: !emptyPosition(fromPos)
requires: emptyPosition(toPos)

ensures: emptyPosition(fromPos)
ensures: !emptyPosition(toPos)

Parameters:

fromPos - source position text

toPos - destination position text

positionSelected

public boolean positionSelected(int line,
                                int column)

Is position (line,column) selected?

requires: validPosition(line, column)

Parameters:

line - line number

column - column number

Returns:

boolean true if position is selected, otherwise it returns false

positionSelected

public boolean positionSelected(java.lang.String pos)

Is position pos selected?

requires: validPosition(pos)

Parameters:

pos - position text

Returns:

boolean true if position is selected, otherwise it returns false

selectPosition

public void selectPosition(int line,
                           int column)

Select position (line,column).

requires: !positionSelected(line, column)

ensures: positionSelected(line, column)

Parameters:

line - line number

column - column number

selectPosition

public void selectPosition(java.lang.String pos)

Select position pos.

requires: !positionSelected(pos)

ensures: positionSelected(pos)

Parameters:

pos - position text

unselectPosition

public void unselectPosition(int line,
                             int column)

Unselect position (line,column).

requires: positionSelected(line, column)

ensures: !positionSelected(line, column)

Parameters:

line - line number

column - column number

unselectPosition

public void unselectPosition(java.lang.String pos)

Unelect position pos.

requires: positionSelected(pos)

ensures: !positionSelected(pos)

Parameters:

pos - position text