/**
* Returns a list with the valid Plies of this <code>Rook</code>, as specified in the overview.
*
* @return A <code>List</code> of valid <code>Plies</code> for this <code>Rook</code>; if the
* <code>Rook</code> is not currently in a <code>Board</code>, the <code>List</code> will be
* empty.
*/
public List<Ply> getPlies() {
checkRep();
Board board = getBoard();
// Create list of valid cells to move to
List<int[]> validCells = new LinkedList<int[]>();
List<Ply> validPlies = new ArrayList<Ply>();
if (board.contains(this)) {
int[] pos = board.getPosition(this);
int[] temp = new int[2];
// Get positions where rook can move (horizontally or vertically)
for (int i = 0; i < 4; i++) {
// 0 = north; 1 = east; 2 = south; 3 = west
temp = oneCellNext(pos, i);
while (board.isUsable(temp)
&& (board.isEmpty(temp)
|| ((board.getPiece(temp).isWhite() && !isWhite())
|| (!board.getPiece(temp).isWhite() && isWhite())))) {
validCells.add(temp.clone());
if (!board.isEmpty(temp)
&& ((board.getPiece(temp).isWhite() && !isWhite())
|| (!board.getPiece(temp).isWhite() && isWhite()))) break;
temp = oneCellNext(temp, i);
}
}
// Create list of valid moves
for (int[] validCell : validCells) validPlies.add(new Move(pos, validCell));
}
checkRep();
return validPlies;
}
