en passant OK

src/backend/Board.java

@@ -11,6 +11,10 @@ public class Board {
 	private int x;
 	private int y;
 	private int turnNumber;
+	private boolean lastTurnPawnTwo = false;//for en passant
+	private int xTwo;
+	private int yTwo;
+	private boolean enPassant = false;
 	
 	public Board(int colNum, int lineNum) {
 		this.colNum = colNum;
@@ -162,9 +166,25 @@ public class Board {
 					}
 				}
 				if(((this.positionOccupied(x, y) == false || pieces.get(whatPiece(x,y)).isWhite() != pieces.get(whatPiece(this.x,this.y)).isWhite())) && (highlights)) {//moves the piece only if the position selected is not occupied by a piece of the same color
+					if (enPassant) {
+						this.pieces.remove(whatPiece(xTwo,yTwo));
+						enPassant = false;
+					}
+					
 					int indexPiece = this.whatPiece(this.x, this.y);
+					
+					if (pieces.get(indexPiece).getType() == PieceType.Pawn && Math.abs(this.y-y)==2) {//save the number of the turn at which a pawn moved by two
+						lastTurnPawnTwo = true;
+						xTwo = x;
+						yTwo = y;
+					}
+					else {
+						lastTurnPawnTwo = false;
+					}
+					
 					pieces.get(indexPiece).setX(x);
 					pieces.get(indexPiece).setY(y);
+					
 					this.turnNumber +=1;
 				}
 				
@@ -352,13 +372,24 @@ public class Board {
 		boolean highlight = false;
 		if (positionOccupied(this.x,this.y)) { //check if we have selected a position with a piece
 			int indexPieceSelect = whatPiece(this.x,this.y);
+			
 			if (pieces.get(indexPieceSelect).getType() == PieceType.Pawn) {//highlight for pawns
 				
 				if (pieces.get(indexPieceSelect).isWhite()) {//white pawns 
+					
+					if (lastTurnPawnTwo) {//en passant
+						if(yTwo == this.y && Math.abs(xTwo - this.x) == 1 && x == xTwo && y == this.y - 1) {
+							highlight = true;
+							enPassant = true;
+						}
+					}
+					
 					if(y == this.y-1) {
 						if((x == this.x) && (positionOccupied(x,y)==false)) {//advance one case
 							highlight = true;
 						}
+						
+						
 						if((Math.abs(x-this.x) == 1) && (positionOccupied(x,y)) && pieces.get(whatPiece(x,y)).isWhite() != pieces.get(indexPieceSelect).isWhite()) {//highlight the piece in diagonal, if existing and of another color
 							highlight = true;
 						}
@@ -370,9 +401,18 @@ public class Board {
 				
 				if (pieces.get(indexPieceSelect).isWhite() == false) {//black pawns 
 					if(y == this.y+1) {
+						
+						if (lastTurnPawnTwo) {//en passant
+							if(yTwo == this.y && Math.abs(xTwo - this.x) == 1 && x == xTwo && y == this.y+1) {
+								highlight = true;
+								enPassant = true;
+							}
+						}
+						
 						if((x == this.x) && (positionOccupied(x,y)==false)) {
 							highlight = true;
 						}
+						
 						if((Math.abs(x-this.x) == 1) && (positionOccupied(x,y))  && pieces.get(whatPiece(x,y)).isWhite() != pieces.get(indexPieceSelect).isWhite()) {
 							highlight = true;
 						}