mainmenu.md

Creating the Main Menu Screen

In our game, the main menu screen will present the user with options for:

1. exiting the application
2. creating a player (required in order to start the adventure)
3. starting the adventure (will be hidden until a player is created)

Making the Main menu screen

The Main menu screen, or MainScreen, will display the top-level menu items to the user, prompt the user until an appropriate selection is made, and then load the relevant screen.

The Screen superclass provides menu capabilities by default, and MainScreen will just use those.

To create the set of menu items, override setupMenu(). Call the superclass method first, in case it needs to initialize some things. Next, call menu.addItem to add each menu item.

Menu items are typically key/value pairs, where:

• the key is a string that is used as the menu's label.
• the value is a function. If you give menu.addItem a Screen subclass, it creates a function that will load the given screen.

menu.addItem has a 3-argument constructor, where the 3rd option is a boolean where the value true will hide the menu item from console output. The following function adds 3 items to the screen's menu. The first 2 items contain references to locally defined functions that will execute when its respective menu item is chosen. The third menu item will EVENUTALLY navigate the player to the EntranceScreen when it is selected. For now, let's just point it to a stub function. Note that the third item is hidden initially, but will unhide once the user has created a player (i.e., selected the second menu item).

@Override
public void setup() {
    super.setup();
    menu.addItem("Exit game", exitProgram);
    menu.addItem("Create player", createPlayer);
    menu.addItem("Start the adventure", startAdventure, true);
}

The exitProgram function prints out a simple message and then calls Screen's exit() function. The exitProgram function is a functional interface of type MenuItemMethod and can be declared as:

private MenuItemMethod exitProgram = () -> {
    System.out.println("Exiting main screen...");
    exit();
};

The createPlayer function prompts and receives a player name from the user and creates a new Player object from the game's Player class. The Player class is a simple POJO that has the game-specific info that we want for keeping track of the user playing the game. For this tutorial, it will be just the player's name.

First, create a package called characters. The Player class will go in this package.

Next, make the Player class using the code below:

Player.java

package docrob.cag.mygame.characters;

import lombok.*;

@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
@ToString
public class Player {
    private String name;

}

Note that the Player class is part of this example game and not provided by the framework. If your game needs a data type to represent the user then feel free to create your own, or use the one provided below as a model.

After creating the player object, we save it to the game's global state manager, which is a key/value store:

• the key is a string representing whatever you are storing
• the value is the object that is being stored

Note that the Game object is a singleton and must have its getInstance function called before you can call any of its methods.

Lastly, after the player is created and stored, we unhide the "Start the adventure" menu item.

private MenuItemMethod createPlayer = () -> {
    String name = Game.getInstance().getInput().getString("\nEnter your name: ");
    Player player = new Player(name);
    Game.getInstance().addStateItem("player", player);

    menu.getItemFromLabel("Start the adventure").setHidden(false);
};

The final menu item function is a simple stub:

private MenuItemMethod startAdventure = () -> {
    System.out.println("TODO: start the adventure");
};

Next, we need to override the show function that outputs the screen's description to the console. If you are using Screen's built-in menu, then you should call super.show() before or after your screen's description, depending on whether you want the menu options to print before or after your screen's description.

For MainScreen, we also want to print the player's name to visually confirm that a player has been created. Note that we call Game's getStateItem function to give us the player's object if it has been created. We tell getStateItem the data type of the object so that it may cast it for us before returning it.

@Override
protected void show() {
    Player player = Game.getInstance().getStateItem("player", Player.class);
    String playerInfo = "";
    if(player != null) {
        playerInfo = "\t\tPlayer: " + player.getName();
    }
    System.out.println(ConsoleColors.ANSI_CLEAR + "\nMain Screen" + playerInfo);

    super.show();
}

Finally, we need to hook up the WelcomeScreen to transition to then MainScreen after the user presses the enter key. Here is the revised handleInput function in the WelcomeScreen. WelcomeScreen

@Override
protected void handleInput() {
    Game.getInstance().getInput().getString("Press Enter to continue.");

    ScreenManager.addScreen(new MainScreen());
}

Below is the complete MainScreen.java.

You should now be able to run the game, make a player by providing a player name, select "Start the adventure", and exit the game.

package docrob.cag.mygame.screens;

import docrob.cag.framework.menu.MenuItemMethod;
import docrob.cag.framework.screens.Screen;
import docrob.cag.framework.state.Game;
import docrob.cag.framework.utils.ConsoleColors;

public class MainScreen extends Screen {

    public MainScreen() {
    }

    @Override
    public void setup() {
        super.setup();
        menu.addItem("Exit game", exitProgram);
        menu.addItem("Create player", createPlayer);
        menu.addItem("Start the adventure", startAdventure, true);
    }

    @Override
    protected void show() {
        Player player = Game.getInstance().getStateItem("player", Player.class);
        String playerInfo = "";
        if (player != null) {
            playerInfo = "\t\tPlayer: " + player.getName();
        }
        System.out.println(ConsoleColors.ANSI_CLEAR + "\nMain Screen" + playerInfo);

        super.show();
    }

    private MenuItemMethod createPlayer = () -> {
        String name = Game.getInstance().getInput().getString("\nEnter your name: ");
        Player player = new Player(name);
        Game.getInstance().addStateItem("player", player);

        menu.getItemFromLabel("Start the adventure").setHidden(false);
    };

    private MenuItemMethod exitProgram = () -> {
        System.out.println("Exiting main screen...");
        setReadyToExit();
    };

    private MenuItemMethod startAdventure = () -> {
        System.out.println("TODO: start the adventure");
    };
}

Next: the adventure's starting screen