MainMenu.java

import greenfoot.Color;
import greenfoot.Greenfoot;
import greenfoot.GreenfootImage;
import greenfoot.World;

import javax.swing.*;
import java.io.File;
import java.util.ArrayList;

/**
 * Main song selection menu.
 *
 * @author Team APCSA 2019
 * @author Andy Ge
 * @author Andrew Vittiglio
 * @author Steve Rosario
 * @author Yijie Gui
 * @author Russell Doucet
 * @author William LoGiudice
 * @author Maanik George
 * @author Mr. Gilmore (Teacher)
 * @version 2019-05-24 20:37
 */
public class MainMenu extends World
{
    /**
     * Constructor for objects of class MainMenu.
     */
    public MainMenu()
    {
        super(Constants.WIDTH, Constants.HEIGHT, 1);

        // Get the beatmap sets.
        ArrayList<File> beatmapSets = BeatmapReader.listBeatmapSets();

        // Draw the background
        drawBackground();

        // Put song selection buttons in.
        putSongSelectionButtons(beatmapSets);
    }

    /**
     * Draw the background
     */
    private void drawBackground()
    {
        // Draw wallpaper
        {
            GreenfootImage wallpaper = new GreenfootImage(Images.WALLPAPER);
            int origWidth = wallpaper.getWidth();
            int origHeight = wallpaper.getHeight();
            wallpaper.scale((int) (1.0 * origWidth / origHeight * Constants.HEIGHT), Constants.HEIGHT);
            getBackground().drawImage(wallpaper, 0, 0);
        }

        // Darken wallpaper with a black overlay
        {
            Images.BLACK.scale(Constants.WIDTH, Constants.HEIGHT);
            Images.BLACK.setTransparency(Constants.GRAPHIC_WALLPAPER_DARKEN);
            getBackground().drawImage(Images.BLACK, 0, 0);
        }

        // Draw "Song Select"
        {
            // Get text and make an image
            GreenfootImage text = new GreenfootImage("Song Select", 20, Color.WHITE, null);

            // Calculate the x and y that the text is centered within a separation space.
            int x = Constants.WIDTH / 2 - text.getWidth() / 2;
            int y = (Constants.SELECTION_TOP_PADDING + Constants.SELECTION_MIN_SPACING) / 2 - text.getHeight() / 2;

            // Draw it
            getBackground().drawImage(text, x, y);
        }
        
        // Put in Key bind editors
        {
            for (int i = 0; i < Constants.NUM_COLS; i++)
            {
                KeyBindEditor keyBindEditor = new KeyBindEditor(i);
                addObject(keyBindEditor, 0, 0);
                keyBindEditor.init();
            }
        }
    }

    /**
     * Put the song selection buttons, MainMenuSongCover, in the world.
     *
     * @param beatmapSets Beatmap sets
     */
    private void putSongSelectionButtons(ArrayList<File> beatmapSets)
    {
        for (int i = 0; i < beatmapSets.size(); i++)
        {
            File beatmapSetDirectory = beatmapSets.get(i);
            MainMenuSongCover songSelect = new MainMenuSongCover(beatmapSetDirectory, i);
            addObject(songSelect, 0, 0);
            songSelect.init();
        }
    }

    /**
     * Show a dialog to select song. This method is used before this
     * menu existed.
     */
    @Deprecated
    public static void launchSongSelectionDialog()
    {
        // Optimization: Use a different thread.
        new Thread(() ->
        {
            // List beatmap sets.
            ArrayList<File> beatmapSets = BeatmapReader.listBeatmapSets();
            StringBuilder text = new StringBuilder("Please choose a beatmap.\nAvailable Beatmaps:\n");

            for (File beatmapSet : beatmapSets)
            {
                text.append("- ").append(beatmapSet.getName()).append("\n");
            }

            text.append("Please input the beatmap ID:");

            // Read user input
            String beatmapId = JOptionPane.showInputDialog(text);

            // Verify input
            File beatmapSet = BeatmapReader.findBeatmapSetById(beatmapId);
            if (beatmapSet == null)
            {
                JOptionPane.showMessageDialog(null, "Error: Beatmap not found.");
                throw new RuntimeException("Error: Beatmap not found.");
            }

            // List difficulties
            ArrayList<String> diffs = BeatmapReader.listDifficulties(beatmapSet);
            text = new StringBuilder("Please choose a difficulty:\n");

            for (String diff : diffs)
            {
                text.append("- ").append(diff).append("\n");
            }

            text.append("Please input the difficulty of your choice:");

            // Read user input
            String difficulty = JOptionPane.showInputDialog(text);

            // Make world
            BeatmapWorld beatmapWorld = new BeatmapWorld(beatmapSet, difficulty);
            Greenfoot.setWorld(beatmapWorld);
            beatmapWorld.startGame();

        }).start();
    }

    /**
     * Launch the world as fast as possible.
     */
    public static void launchTest()
    {
        BeatmapWorld world = new BeatmapWorld("398366", "Normal");
        Greenfoot.setWorld(world);
        world.startGame();
    }
}