java - How to combine event listeners with "asking" for an event?

Question

I wrote a simple little maze game for a terminal which repeatedly asks the user to do something (e.g. "In which direction would you like to go? [N/E/S/W]"). I have a navigate() method running in a loop that fires off these questions, stores their answers and does something depending on the answer.

public enum Dir (N, E, S, W);

public void navigate() {
    Dir nextDir = utils.askDirection("Which way do you want to go?");
    // Do stuff with answer, like changing position of user in maze
}

Now, I've written a simple GUI for my game. I deliberately put all the references to the terminal in a ConsoleUtils class which implements a Utils interface (this has methods like askQuestion()) - the idea being that I could create a GuiUtils class and have my game either as a terminal game or as a GUI game.

The problem is that the navigate method asks the user a question and then "waits" for the response, which the Utils class gives it by using a Scanner to read the newest line of input. However if I use Event Listeners for the new N/E/S/W buttons in my GUI, they fire off events regardless whether the navigate method has asked for one or not. --> Image of GUI

Is there any way I can combine this or do I need to write a new navigate method for the GUI?

(To be honest, I'm also not entirely sure whether my GUI class should instantiate a game class, in which case the logic for navigate could end up in a GUI method anyway, or whether the game should have a GUI. I haven't written any code for the event listener either yet, since I'm not sure which class should be calling which. This is probably a separate question.)

Answer 1

Your text based game has a loop that repeatedly asks questions to gather user input. Swing provides this loop for you by continually executing Runnable blocks of code that have been posted to the EventQueue. For example, when the user presses a button labeled E, code is posted to the queue that invokes your ActionEvent implementation to handle your game's interpretation of the move east command.

For reference, a complete example of a very simple guessing game is examined here. In pseudocode, the corresponding text based game might look like this:

initialize
loop
    prompt "Guess what color!"
    get chosenColor
    if chosenColor = actualColor
        say "You win!"
        reset game
    else
        say "Keep trying."
end loop

A more elaborate game cited there includes the original text-based source.