Coding the other interfaces

There are three more interfaces that we need to code. They are for communications between specific classes of the game. We need the GameState class to be able to trigger a new level via the GameEngine class and we will code the EngineController interface for that.

We will need the GameEngine class to broadcast to multiple input related classes whenever the player interacts with the screen and we will need these input-related classes to register themselves as observers just as we did in the previous project. For this we will code the GameEngineBroadcaster interface and the InputObserver interface.

Let's quickly add them now.

EngineController

Add the EngineController interface as shown next.

interface EngineController {
    // This allows the GameState class to start a new level
    void startNewLevel();
}

In the next chapter we will make GameEngine implement this interface as well as pass a reference to GameState. GameState will then be able to call the startNewLevel...