Chessboard bugfix

src/Chessboard.java

@@ -213,6 +213,7 @@ public class Chessboard extends JPanel {
      * @return piece
      */
     public IPiece getPiece(PiecePosition pos) {
+        if(pos.y < 0 || pos.y >= SQUARE_COUNT || pos.x < 0 || pos.x >= SQUARE_COUNT) return null;
         return pieces[pos.y][pos.x];
     }
 

src/ChessboardMouseAdapter.java

@@ -1,6 +1,5 @@
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
-import java.util.ArrayList;
 import java.util.List;
 
 /**