Added check detection

+ Position class and implementation (mostly pieces)
+ King position tracking, check detection and utility functions related
to Position in Board

src/dev/kske/chess/Board.java

@@ -1,11 +1,15 @@
 package dev.kske.chess;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import dev.kske.chess.piece.Bishop;
 import dev.kske.chess.piece.King;
 import dev.kske.chess.piece.Knight;
 import dev.kske.chess.piece.Pawn;
 import dev.kske.chess.piece.Piece;
 import dev.kske.chess.piece.Piece.Color;
+import dev.kske.chess.piece.Piece.Type;
 import dev.kske.chess.piece.Queen;
 import dev.kske.chess.piece.Rook;
 
@@ -18,9 +22,11 @@ import dev.kske.chess.piece.Rook;
 public class Board {
 
 	private Piece[][]				boardArr;
+	private Map<Color, Position>	kingPos;
 
 	public Board() {
 		boardArr		= new Piece[8][8];
+		kingPos	= new HashMap<>();
 		initializeDefaultPositions();
 	}
 
@@ -33,26 +39,56 @@ public class Board {
 		if (piece == null || !piece.isValidMove(move)) return false;
 		else {
 			// Move piece
+			// Save destination piece for possible canceling of the move
+			Piece tmpPiece = getDest(move);
 			setDest(move, getPos(move));
 			setPos(move, null);
+
+			// Revert move if it caused a check for its team
+			if (checkCheck(piece.getColor())) {
+				setPos(move, getDest(move));
+				setDest(move, tmpPiece);
+				return false;
+			}
+
+			// Update the king's position if the moved piece is a king
+			if (piece.getType() == Type.KING) kingPos.put(piece.getColor(), move.dest);
+
 			return true;
 		}
 	}
 
+	public boolean checkCheck(Color color) {
+		for (int i = 0; i < 8; i++)
+			for (int j = 0; j < 8; j++)
+				if (boardArr[i][j] != null && boardArr[i][j].getColor() != color
+						&& boardArr[i][j].isValidMove(new Move(new Position(i, j), kingPos.get(color))))
+					return true;
+		return false;
+	}
+
+	public Piece get(Position pos) {
+		return boardArr[pos.x][pos.y];
+	}
+
+	public void set(Position pos, Piece piece) {
+		boardArr[pos.x][pos.y] = piece;
+	}
+
 	public Piece getPos(Move move) {
-		return boardArr[move.xPos][move.yPos];
+		return get(move.pos);
 	}
 
 	public Piece getDest(Move move) {
-		return boardArr[move.xDest][move.yDest];
+		return get(move.dest);
 	}
 
 	public void setPos(Move move, Piece piece) {
-		boardArr[move.xPos][move.yPos] = piece;
+		set(move.pos, piece);
 	}
 
 	public void setDest(Move move, Piece piece) {
-		boardArr[move.xDest][move.yDest] = piece;
+		set(move.dest, piece);
 	}
 
 	/**
@@ -69,6 +105,10 @@ public class Board {
 		boardArr[4][0]	= new King(Color.BLACK, this);
 		boardArr[4][7]	= new King(Color.WHITE, this);
 
+		// Initialize king position objects
+		kingPos.put(Color.BLACK, new Position(4, 0));
+		kingPos.put(Color.WHITE, new Position(4, 7));
+
 		// Initialize queens
 		boardArr[3][0]	= new Queen(Color.BLACK, this);
 		boardArr[3][7]	= new Queen(Color.WHITE, this);

src/dev/kske/chess/Move.java

@@ -8,17 +8,20 @@ package dev.kske.chess;
  */
 public class Move {
 
-	public final int xPos, yPos, xDest, yDest, xDist, yDist, xSign, ySign;
+	public final Position	pos, dest;
+	public final int		xDist, yDist, xSign, ySign;
+
+	public Move(Position pos, Position dest) {
+		this.pos	= pos;
+		this.dest	= dest;
+		xDist		= Math.abs(dest.x - pos.x);
+		yDist		= Math.abs(dest.y - pos.y);
+		xSign		= (int) Math.signum(dest.x - pos.x);
+		ySign		= (int) Math.signum(dest.y - pos.y);
+	}
 
 	public Move(int xPos, int yPos, int xDest, int yDest) {
-		this.xPos	= xPos;
+		this(new Position(xPos, yPos), new Position(xDest, yDest));
-		this.yPos	= yPos;
-		this.xDest	= xDest;
-		this.yDest	= yDest;
-		xDist		= Math.abs(xDest - xPos);
-		yDist		= Math.abs(yDest - yPos);
-		xSign		= (int) Math.signum(xDest - xPos);
-		ySign		= (int) Math.signum(yDest - yPos);
 	}
 
 	public boolean isHorizontal() { return yDist == 0; }

src/dev/kske/chess/Position.java

@@ -0,0 +1,17 @@
+package dev.kske.chess;
+
+/**
+ * Project: <strong>Chess</strong><br>
+ * File: <strong>Position.java</strong><br>
+ * Created: <strong>02.07.2019</strong><br>
+ * Author: <strong>Kai S. K. Engelbart</strong>
+ */
+public class Position {
+
+	public final int x, y;
+
+	public Position(int x, int y) {
+		this.x	= x;
+		this.y	= y;
+	}
+}

src/dev/kske/chess/piece/Bishop.java

@@ -22,8 +22,8 @@ public class Bishop extends Piece {
 
 	@Override
 	protected boolean isFreePath(Move move) {
-		for (int i = move.xPos + move.xSign, j = move.yPos
+		for (int i = move.pos.x + move.xSign, j = move.pos.y
-				+ move.ySign; i != move.xDest; i += move.xSign, j += move.ySign)
+				+ move.ySign; i != move.dest.x; i += move.xSign, j += move.ySign)
 			if (board.getBoardArr()[i][j] != null) return false;
 		return checkDestination(move);
 	}

src/dev/kske/chess/piece/Pawn.java

@@ -21,8 +21,8 @@ public class Pawn extends Piece {
 		boolean	step		= move.isVertical() && move.yDist == 1;
 		boolean	doubleStep	= move.isVertical() && move.yDist == 2;
 		boolean	strafe		= move.isDiagonal() && move.xDist == 1;
-		if (getColor() == Color.WHITE) doubleStep &= move.yPos == 6;
+		if (getColor() == Color.WHITE) doubleStep &= move.pos.y == 6;
-		else doubleStep &= move.yPos == 1;
+		else doubleStep &= move.pos.y == 1;
 		return (step ^ doubleStep ^ strafe) && move.ySign == (getColor() == Color.WHITE ? -1 : 1) && isFreePath(move);
 	}
 
@@ -30,7 +30,7 @@ public class Pawn extends Piece {
 	protected boolean isFreePath(Move move) {
 		// Two steps forward
 		if (move.yDist == 2)
-			return board.getBoardArr()[move.xPos][move.yDest - move.ySign] == null && checkDestination(move);
+			return board.getBoardArr()[move.pos.x][move.dest.y - move.ySign] == null && checkDestination(move);
 		// One step forward
 		else if (move.xDist == 0) return board.getDest(move) == null;
 		// Capture move

src/dev/kske/chess/piece/Queen.java

@@ -23,14 +23,14 @@ public class Queen extends Piece {
 	@Override
 	protected boolean isFreePath(Move move) {
 		if (move.isHorizontal()) {
-			for (int i = move.xPos + move.xSign; i != move.xDest; i += move.xSign)
+			for (int i = move.pos.x + move.xSign; i != move.dest.x; i += move.xSign)
-				if (board.getBoardArr()[i][move.yPos] != null) return false;
+				if (board.getBoardArr()[i][move.pos.y] != null) return false;
 		} else if (move.isVertical()) {
-			for (int i = move.yPos + move.ySign; i != move.yDest; i += move.ySign)
+			for (int i = move.pos.y + move.ySign; i != move.dest.y; i += move.ySign)
-				if (board.getBoardArr()[move.xPos][i] != null) return false;
+				if (board.getBoardArr()[move.pos.x][i] != null) return false;
 		} else {
-			for (int i = move.xPos + move.xSign, j = move.yPos
+			for (int i = move.pos.x + move.xSign, j = move.pos.y
-					+ move.ySign; i != move.xDest; i += move.xSign, j += move.ySign)
+					+ move.ySign; i != move.dest.x; i += move.xSign, j += move.ySign)
 				if (board.getBoardArr()[i][j] != null) return false;
 		}
 		return checkDestination(move);

src/dev/kske/chess/piece/Rook.java

@@ -23,11 +23,11 @@ public class Rook extends Piece {
 	@Override
 	protected boolean isFreePath(Move move) {
 		if (move.isHorizontal()) {
-			for (int i = move.xPos + move.xSign; i != move.xDest; i += move.xSign)
+			for (int i = move.pos.x + move.xSign; i != move.dest.x; i += move.xSign)
-				if (board.getBoardArr()[i][move.yPos] != null) return false;
+				if (board.getBoardArr()[i][move.pos.y] != null) return false;
 		} else {
-			for (int i = move.yPos + move.ySign; i != move.yDest; i += move.ySign)
+			for (int i = move.pos.y + move.ySign; i != move.dest.y; i += move.ySign)
-				if (board.getBoardArr()[move.xPos][i] != null) return false;
+				if (board.getBoardArr()[move.pos.x][i] != null) return false;
 		}
 		return checkDestination(move);
 	}