How to get addMouseListener to work with GridWorld's World?

Question

I'm supposed to make a connect four game in gridworld with Pieces as the discs but my teacher for some reason told us nothing about the mouselistener! so i did look it up a little but i still cant figure out how to add a mouse listener to the grid to track mouse clicks.

PS: If you really want the code for the Piece class i can add it, and im pretty sure that World extends Jframe.

import java.awt.Color;    
import java.util.ArrayList;

import info.gridworld.grid.Grid;
import info.gridworld.grid.Location;
import info.gridworld.world.World;
import info.gridworld.grid.BoundedGrid;

import java.awt.MouseInfo;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class ConnectFourWorld extends World<Piece> implements MouseListener
{
   private String whosTurn;
   private boolean gameOver;
   private String winner;
   Piece X = new Piece("ex", Color.WHITE, Color.RED);
   Piece O = new Piece("oh", Color.YELLOW, Color.BLUE);


   public ConnectFourWorld()
   {
    super(new BoundedGrid<Piece>(6,7));

    winner="no winner";
    whosTurn="X";
    gameOver=false;
      setMessage("Welcome to Connect Four World!  - -  Click a spot - "+whosTurn+"'s             turn.");           
   }

   public boolean locationClicked(Location loc)
   {
        Grid<Piece> grid = getGrid();
      if(grid == null)
        return false;

      if(grid.get(loc)!=null)
        return false;

      if(gameOver == true)
      {

        return false;
      }



      return true;  
   }

   public Location addPiece(Location loc)
   {

      return null;  
   }

  public void step()
   {    
   }

   public boolean isWorldFull()
   {
    return false;
   }

   public void resetWorld()
   {
   }

   public String getWinner(Location loc)
   {
        return "";
   }

@Override
public void mouseClicked(MouseEvent e) {
    if(e.getButton()==1&&whosTurn.equals("X")){

    }
}

@Override
public void mouseEntered(MouseEvent e) {

}

@Override
public void mouseExited(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mousePressed(MouseEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void mouseReleased(MouseEvent e) {
    // TODO Auto-generated method stub

    }
}

Answer 1

No. The instance variable of the World class are:

public class World<T>
{
    private Grid<T> gr;
    private Set<String> occupantClassNames;
    private Set<String> gridClassNames;
    private String message;
    private JFrame frame;

    private static Random generator = new Random();

    private static final int DEFAULT_ROWS = 10;
    private static final int DEFAULT_COLS = 10;
    ...
}

So in fact World is not a JFrame, but in fact has one, which is inaccessible because it's private. You could, however, create your own world class that merely changes the private JFrame to a protected JFrame, and then extend that. You could then access the JFrame and add a mouse Listener by using

WorldVariableName.frame.addMouseListener(new listener).

P.S. I've always thought it better to create a separate private MouseListener class in the main class rather than implementing MouseListener in the main class.

Answer 2

You could have used Reflection to bypass the accessibility restrictions though that is well out of your scope if you are not even required to make your own World class.

Fields[] fields = World.class.getDeclaredFields();

for(Field f: fields){
    if(f.getName().equalsIgnoreCase("frame")){
        try{
            f.setAccessible(true);
            JFrame frame = (JFrame) f.get(worldInstance);
            f.setAccessible(false);
            return frame;
        }catch(IllegalArgumentException | IllegalAccessException e){
            e.printStackTrace();
        }
   }
}

return null;

That is what I had done to grab the JFrame by force so I can use click and key presses without their restrictions.