Question

I’m implementing a game and I have some clases like:

GameObject (Abstract)
CircularGameObject
RectangularGameObject

They basically store the position (x,y) and the different shapes for checking collisions.

Now I want to implement the classes Wall (Rectangular) and Bomb (Circular). Both can be enabled or disabled so I declare

 public interface Activable {

     public void setEnabled(boolean status);
     public boolean isEnabled();
 }

And I have one List for storing a reference to the items that kills the player on the collisions (Walls and Bombs).
How can I declare an ArrayList of objects that extends GameObject and implements Activable?

I tried declaring a class:

 public class ActivableGameObject extends GameObject implements Activable{};

but the compiler doesn’t allow to assign to that reference a Bomb for example (Because is a CircularGameObject)

Answer 1

One way would be be to have:

`GameObject implements GameObjectInterface {}`

then:

`Activable extends GameObjectInterface`

That way you can use have make the array use Activable.