Update Implementation AIGridGUI class

src/main/java/BattleShip/AIGridGUI.java

@@ -464,6 +464,17 @@ public class AIGridGUI extends JPanel {
                 }
                 clear = false;
             }
+
+            if(e.getButton() == MouseEvent.BUTTON3) {
+                //Toggle whether ship placement is vertical or horizontal.
+                vertical = !vertical;
+                for(BSButton bsb : buttons) {
+                    if(bsb.getCellContents() == null) {
+                        bsb.setBorder(defaultBorder);
+                    }
+                }
+                highlightCells(cell, 0);
+            }
         }
 
         public void mouseExited(MouseEvent e) {