Myujth

I have been building a multiplayer checker game for my class project.
The below code is in Room class because every game should have a checkerboard.

I converted to 2D List because Firebase does not serialize arrays.

Each of object stored in the list is a subclass of Checker, including nullc (a substitute for null). The reason why I store nullc in the list is that the list has two rows consist of only nulls, and Firebase does not store the index of those two rows.

this.checkerList = new ArrayList<List<Checker>>();
Checker nullc = new NullChecker();
Checker checkerArray = new Checker
 nullc, new RedChecker(0,1), nullc, new RedChecker(0,3),
 nullc, new RedChecker(0,5), nullc, new RedChecker(0,7),
 new RedChecker(1,0), nullc, new RedChecker(1,2),nullc, new RedChecker(1,4), nullc, new RedChecker(1,6), nullc,
 nullc, new RedChecker(2,1), nullc, new RedChecker(2,3), nullc, new RedChecker(2,5), nullc, new RedChecker(2,7),
 nullc, nullc, nullc, nullc,nullc, nullc,nullc, nullc,
 nullc, nullc, nullc, nullc,nullc, nullc,nullc, nullc,
 new BlackChecker(5,0), nullc, new BlackChecker(5,2),nullc, new BlackChecker(5,4), nullc, new BlackChecker(5,6), nullc,
 nullc, new BlackChecker(6,1), nullc, new BlackChecker(6,3), nullc, new BlackChecker(6,5), nullc, new BlackChecker(6,7),
 new BlackChecker(7,0), nullc, new BlackChecker(7,2),nullc, new BlackChecker(7,4), nullc, new BlackChecker(7,6), nullc;

for(int r = 0; r < checkerArray.length; r++)
 List <Checker> row = new ArrayList <Checker>();
 for(int c = 0; c < checkerArray[r].length; c++)
 row.add(checkerArray[r][c]);
 
 this.checkerList.add(row);

The problem I have now is the list stores fine in Firebase database. However, when I retrieve the whole list from the database, the subclasses are not subclasses anymore.

 refThisRoom.addValueEventListener(new ValueEventListener() 
 @Override
 public void onDataChange(@NonNull DataSnapshot dataSnapshot) 
 if(dataSnapshot.getValue(Room.class).getPlayer2() != null)
 turn = dataSnapshot.getValue(Room.class).getTurn();
 checkerList = dataSnapshot.getValue(Room.class).getCheckerList();

 for(int r = 0; r < checkerList.size(); r++)
 Log.d("checkerList", "row" + String.valueOf(r));
 Log.d("checkerList", "rowSize" + String.valueOf(checkerList.size()));
 for(int c = 0; c < checkerList.get(r).size(); c++)
 Log.d("checkerList", "Column" + String.valueOf(c));
 Log.d("checkerList", "ColumnSize" + String.valueOf(checkerList.get(r).size()));
 Log.d("checkerList","hello: "+checkerList.get(r).get(c).getClass().getSimpleName());
 

 
 Toast.makeText(BlackCheckerActivity.this,"Player Entered",Toast.LENGTH_LONG).show();
 updateAllButtons();
 disableButtons();
 
 else
 Toast.makeText(BlackCheckerActivity.this,"Waiting for another player",Toast.LENGTH_LONG).show();
 
 

 @Override
 public void onCancelled(@NonNull DatabaseError databaseError) 

 
 );

Instead of returning BlackChecker, RedChecker, and NullChecker, it is just returning checker. I am stuck now because I am using instanceof to determine each checker's move.

I solved the issue by adding another field called "type" of type string to the parent class in the constructor. For the subclasses, when I create a subclass, I wrote

 new RedChecker(row, column, "RedChecker")
 new BlackChecker(row, column, "BlackerChecker")
 new NullChecker(row, column, "NullChecker").

When retrieving the list of Checker class back, I replaced all the superclass in the object with newly initiated subclasses. Something like

 if(checkerList.get(r).get(c).getType().equals("Red/Black/NullChecker"))
 checkerList.get(r).set(c, new Red/Black/NullChecker(checkerList.get(r).get(c).getRow(), checkerList.get(r).get(c).getColumn(), checkerList.get(r).get(c).getType())