/**
* Returns the list of pieces that are attacking the king of <code>color</code> or
* <code>null</null> if king is not in check.
*
* @param color King's color.
* @param toKing King's location on the board.
* @return The list of pieces attacking king or <code>null</code> if not in check.
*/
public List<Square> kingAttackers(Color color, Point toKing) {
List<Square> result = null;
final Color opponent = color.getOpponentColor();
Iterator<Square> iter = getIterator(opponent);
while (iter.hasNext()) {
final Square square = iter.next();
if (square.getPiece().isLegalMove(square.getPoint(), toKing, this)) {
if (result == null) {
result = new ArrayList<>();
}
result.add(square);
}
}
return result;
}
