private void pnlBoard_MouseUp(object sender, MouseEventArgs e)
{
// do we know where we dropped?
if (_lastSquareMousedOverCol != null && _lastSquareMousedOverRow != null)
{
// do we know where we started?
if (_squareBeginDragCol != null && _squareBeginDragRow != null)
{
ChessSquare startingSquare = _board.Squares[_squareBeginDragCol.Value, _squareBeginDragRow.Value];
ChessSquare dropSquare = _board.Squares[_lastSquareMousedOverCol.Value, _lastSquareMousedOverRow.Value];
if (_board.AttemptMove(startingSquare, dropSquare))
{
}
}
}
_squareBeginDragCol = null;
_squareBeginDragRow = null;
_currentPieceANMoves = new string[0];
pnlBoard.Invalidate();
}