Drafting surface-level interface for Library/Quizshow communication

LibraryFacade.java

public interface LibraryFacace {
  
  /**
   * Simply opens a socket on a pre-determined port
   * and listens to any messages it receives. It expects that
   * the messages it receives are from instances of the Buzzer App
   * and derives an IP address from them. The library stores this 
   * list of derived IP addresses and uses them to send out messages
   * to all registered devices for the rest of the game session.
   **/
  public startIpRegistration();
  
  /**
   * Close socket that was opened by startIpRegistration().
   **/
  public stopIpRegistration();
  
  /**
   * At this point the Quizshow's IP address
   * should be displayed on the screen for QuizShow
   * participants to type into their devices.
   * 
   * 
   * This method sends out a message to the
   * Buzzer App instances it does so using the list of
   * IP addresses it derived from the packets that were
   * sent to it during the register IP activity.
   * Then it opens a socket on the quizshow's
   * device that listens for registration messages
   * from the Buzzer App instances. 
   * 
   **/
  public void startRegistration();  
  
  /**
   * Send a message to all registered devices that 
   * the team registration period is over.
   **/
  public void endRegistration();
  
  /**
   * Allows the quizshow to retrieve from the library
   * a list of Player objects. Player objects simply
   * aggregate data about a player. I.e. their team
   * name and team color to use for visual display purposes
   * on the quizshow's interface.
   **/
  public ArrayList<Player> getPlayerInfo();
  
  /**
   * Sends a message that the Buzzer App is listening for
   * to activate the big red button on the GamePlay activity.
   **/
  public void startQuestion();
  
  /**
   * Sends a message that the Buzzer App is listening for
   * to de-activate the big red button on the GamePlay activity.
   **/
  public void endQuestion();
  
  /**
   * Closes sockets that were opened during GamePlay. 
   * 
   * Can also contain other essential teardown operations.
   **/
  public void endGame();

}