Question

I’m trying to create a menu screen, and I want to be able to create it, and any further permutations of it dynamically. I’ve created a MenuItem helper class to handle the menu items that show up, and it reads the name, image, and set the next state (something that is handled later). What I want to know is, how can I create the specific following Screens (they’ll all be some subclass of my Screen class)?

What is the most efficient method to pass specific objects into the menuItems? Do I need to pre-create each possible Screen and then just read back in the serialized form of it, or can I create them dynamically. I’d hoped to be able to do something as simple as reading in a literal string “new SubClass(…)” and act off that, but I don’t know how to go about that. Any other suggestions would be great!

Answer 1

If I understand correctly, what you want is a mechanism that reads a String command from a text file, and based on this command, displays a screen.

So, extract the interface of the “display screen” command into an interface. For example:

public interface ScreenDisplayer {
    void displayScreen(Screen mainScreen);
}

Then build a Map<String, ScreenDisplayer>:

map.put("screen1", new ScreenDisplayer() {
    @Override
    void displayScreen(Screen mainScreen) {
        // TODO display screen 1
    });
// same for all the other commands

And when a “menu item” is clicked, get the DisplayScreen from the map and call it:

String command = selectedMenuItem.getCommand();
ScreenDisplayer displayer = map.get(command);
displayer.displayScreen(mainScreen);