private void Chessboard_MouseUp(object sender, MouseEventArgs e)
{
Cursor = Cursors.Default;
if (DragDropOperation.DraggedPiece != null && DragDropOperation.DraggedPiece.Kind != ChessPieceKind.None)
{
if (e.X > DigitAreaWidth && e.X < this.Width && e.Y < Height - LetterAreaHeight && e.Y > 0)
{
// Drops a piece on the board
var destinationSquare = (BoardDirection == BoardDirection.BlackOnTop ?
new ChessSquare((ChessFile)((e.X - DigitAreaWidth) / SquareWidth), (ChessRank)(7 - (e.Y / SquareHeight))) :
new ChessSquare((ChessFile)(7 - (e.X - DigitAreaWidth) / SquareWidth), (ChessRank)(e.Y / SquareHeight)));
var moveValidationResult = ChessEngine.GetMoveValidity(DragDropOperation.Origin, destinationSquare);
if (moveValidationResult.IsValid)
{
var promotionCancelled = false;
if (moveValidationResult.MoveKind.HasFlag(ChessMoveType.Promotion))
{
var pieceChooser = new FrmPromotion(ChessEngine.Turn);
promotionCancelled = pieceChooser.ShowDialog() != DialogResult.OK;
moveValidationResult.PromotedTo = pieceChooser.ChoosePiece;
}
if (!promotionCancelled)
{
moveValidationResult.ToSAN = ChessEngine.MoveToSAN(moveValidationResult); // Update the SAN after promotion
MovePiece(moveValidationResult);
OnPieceMoved?.Invoke(this, moveValidationResult);
if (ChessEngine.IsCheckmate)
{
OnCheckmate?.Invoke(this, new EventArgs());
}
else if (ChessEngine.IsCheck)
{
OnCheck?.Invoke(this, new EventArgs());
}
else if (ChessEngine.IsDraw)
{
OnDraw?.Invoke(this, new EventArgs());
}
}
else
{
Invalidate();
}
}
else
{
Invalidate();
}
}
else
{
// Drops a piece outside of the board
ChessEngine.RemovePieceAt(DragDropOperation.Origin);
Invalidate();
OnPieceRemoved?.Invoke(this, DragDropOperation.Origin, DragDropOperation.DraggedPiece, e.Location);
}
}
DragDropOperation = new DragOperation(null, null);
OnSquareUnselected?.Invoke(this, new EventArgs());
}
/// <summary>
/// Checks whether a move is valid and give the type of move (normal, capture, promotion).
/// In case the move is a promotion, set the <see cref="ChessMove.PromotedTo"/> property accordingly before to pass the return object to the <see cref="MovePiece(ChessMove)"/> method.
/// </summary>
/// <param name="from">Square the piece move from.</param>
/// <param name="to">Square the piece move to.</param>
/// <returns></returns>
/// <exception cref="ArgumentNullException">Thrown when <paramref name="from"/> or <paramref name="to"/> are null.</exception>
public ChessMove CheckMoveValidity(ChessSquare from, ChessSquare to)
{
return(ChessEngine.GetMoveValidity(from, to));
}
