check if mate

src/backend/Board.java

@@ -154,9 +154,11 @@ public class Board {
 	            selectedY = -1; // Unselect
 	            
 	            clearHighlights();
+	            highlightKingInCheck();
 	            System.out.println(toString()); // Work but not sure ?
 	        }
 	    }
+	    
 	}
 		
 	public boolean isSelected(int x, int y) {
@@ -395,5 +397,69 @@ public class Board {
 	    piece.y = move.getToY();
 	    turn++;
 	}
-
+	
+	//Finds the position of the king of a given color.
+	public Piece findKing(boolean isWhite) {
+	    for (int x = 0; x < width; x++) {
+	        for (int y = 0; y < height; y++) {
+	            Piece piece = board[x][y];
+	            if (piece != null && piece.getType() == PieceType.King && piece.isWhite() == isWhite) {
+	                return piece;
+	            }
+	        }
+	    }
+	    return null; // King not found (should not happen in normal chess)
+	}
+	
+	// check king check based on a given color 
+	public boolean isKingInCheck(boolean isWhite) {
+	    // First, find the king's position
+	    Piece king = findKing(isWhite);
+	    
+	    if (king == null) {
+	        // If king not found (shouldn't happen in a valid chess game)
+	        return false;
+	    }
+	    
+	    int kingX = king.getX();
+	    int kingY = king.getY();
+	    
+	    // Check if any enemy piece can attack the king
+	    for (int y = 0; y < height; y++) {
+	        for (int x = 0; x < width; x++) {
+	            Piece piece = board[x][y];
+	            
+	            // Skip empty squares and pieces of the same color as the king
+	            if (piece == null || piece.isWhite() == isWhite) {
+	                continue;
+	            }
+	            
+	            // Get all legal moves for this enemy piece
+	            ArrayList<Move> moves = getLegalMoves(piece);
+	            
+	            // Check if any move can capture the king
+	            for (Move move : moves) {
+	                if (move.getToX() == kingX && move.getToY() == kingY) {
+	                    return true; // King is in check
+	                }
+	            }
+	        }
+	    }
+	    
+	    return false; // King is not in check
+	}
+	
+	private void highlightKingInCheck() {
+	    // Check if white king is in check
+	    Piece whiteKing = findKing(true);
+	    if (whiteKing != null && isKingInCheck(true)) {
+	        highlightedSquares[whiteKing.getX()][whiteKing.getY()] = true;
+	    }
+	    
+	    // Check if black king is in check
+	    Piece blackKing = findKing(false);
+	    if (blackKing != null && isKingInCheck(false)) {
+	        highlightedSquares[blackKing.getX()][blackKing.getY()] = true;
+	    }
+	} // check 
 }