MainMenu.java

/*
* Authors: Jerry Li & Victor Jiang
* Date: June 13, 2025
* Description: This class represents the game main menu screen
*/

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;

public class MainMenu extends JPanel {

    // Constants for button dimensions.
    public static final int BTN_H_SMALL = 100, BTN_W_SMALL = 300;
    public static final int BTN_H_BIG = 140, BTN_W_BIG = 400;

    // Reference to the parent GamePanel.
    public final GamePanel PARENT;

    // Font used for UI elements.
    public final Font UI_FONT;

    // Title label for the main menu.
    public final JLabel TITLE_LABEL;

    // Buttons for different menu options.
    public GameButton how_button;
    public GameButton debug_button;
    public GameButton start_button;

    // Background image for the main menu.
    public BufferedImage background_image;

    // Constructor initializes the main menu and its components.
    public MainMenu(GamePanel parent) {
        PARENT = parent; // Set the parent GamePanel reference.
        setLayout(null); // Use absolute positioning for components.
        setOpaque(false); // Make the panel transparent.
        UI_FONT = parent.getGameFont(); // Retrieve the font from the parent.

        // Initialize and configure the title label.
        TITLE_LABEL = new JLabel("Endless Night");
        TITLE_LABEL.setFont(UI_FONT.deriveFont(Font.BOLD, 90f)); // Set font size and style.
        TITLE_LABEL.setForeground(Color.WHITE); // Set text color to white.
        add(TITLE_LABEL); // Add the title label to the panel.

        // Initialize and configure the "How to Play" button.
        how_button = makeMenuButton("HOW 2 PLAY", 35f, e -> PARENT.game_state = GameState.HOW_TO_PLAY);
        add(how_button); // Add the button to the panel.

        // Initialize and configure the debug menu button (debug builds only).
        debug_button = makeMenuButton("DEBUG MENU", 40f, e -> PARENT.game_state = GameState.DEBUG_MENU);
        if (Settings.DEBUG_MODE) {
            add(debug_button); // Only visible in debug mode
        }

        // Initialize and configure the start button.
        start_button = makeMenuButton("START", 64f, e -> {
            if (Settings.DEBUG_MODE) {
                PARENT.setCurrentWave(DebugConfig.startWave);
                PARENT.playScreen.applyDebugSettings();
            }
            PARENT.game_state = GameState.PLAYING; // Change game state to "PLAYING" when clicked.
        });
        start_button.setColor(new Color(76, 72, 144)); // Set custom color for the button.
        add(start_button); // Add the button to the panel.

        // Load the background image for the main menu.
        loadBackground();
    }

    // Loads the background image from the resources folder.
    public void loadBackground() {
        InputStream in = null;
        try {
            in = getClass().getResourceAsStream("/assets/images/backgrounds/mainmenubg.jpg");
            if (in != null) {
                background_image = ImageIO.read(in);
            } else {
                background_image = null; // Set to null if the image cannot be loaded.
            }
        } catch (IOException e) {
            background_image = null; // Set to null if the image cannot be loaded.
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException ignored) {}
            }
        }
    }

    // Creates a menu button with the specified text, font size, and action
    // listener.
    public GameButton makeMenuButton(String text, float size, ActionListener action) {
        GameButton b = new GameButton(text); // Create a new GameButton with the specified text.
        b.setFont(UI_FONT.deriveFont(Font.BOLD, size)); // Set the font size and style.
        b.addActionListener(action); // Add the action listener to the button.
        b.addMouseListener(new MouseAdapter() {
            // Increase font size when the mouse enters the button.
            public void mouseEntered(MouseEvent e) {
                b.setFont(UI_FONT.deriveFont(Font.BOLD, size * 1.15f));
            }

            // Reset font size when the mouse exits the button.
            public void mouseExited(MouseEvent e) {
                b.setFont(UI_FONT.deriveFont(Font.BOLD, size));
            }
        });
        return b; // Return the configured button.
    }

    // Paints the background image and applies transparency.
    @Override
    protected void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D) g.create(); // Create a copy of the Graphics object.
        if (background_image != null) {
            g2.setComposite(AlphaComposite.SrcOver.derive(0.5f)); // Set transparency to 50%.
            g2.drawImage(background_image, 0, 0, getWidth(), getHeight(), null); // Draw the background image.
        }
        g2.dispose(); // Dispose of the Graphics2D object.
        super.paintComponent(g); // Call the superclass method to paint other components.
    }

    // Repositions components when the panel is invalidated.
    @Override
    public void invalidate() {
        super.invalidate(); // Call the superclass method.
        positionComponents(); // Reposition the components.
    }

    // Positions the components on the panel based on its dimensions.
    public void positionComponents() {
        int w = getWidth() > 0 ? getWidth() : GamePanel.GAME_WIDTH; // Get the panel width or default to game width.
        int h = getHeight() > 0 ? getHeight() : GamePanel.GAME_HEIGHT; // Get the panel height or default to game
                                                                       // height.
        int y_small; // Vertical position for small buttons.
        int x_start; // Horizontal position for the start button.
        int y_start; // Vertical position for the start button.

        // Position the title label at the top-left corner.
        TITLE_LABEL.setBounds(20, 10, TITLE_LABEL.getPreferredSize().width, TITLE_LABEL.getPreferredSize().height);

        // Position the "How to Play" and debug buttons at the bottom.
        y_small = h - BTN_H_SMALL - 60; // Calculate the vertical position for small buttons.
        how_button.setBounds(60, y_small, BTN_W_SMALL, BTN_H_SMALL); // Position the "How to Play" button.
        if (Settings.DEBUG_MODE) {
            debug_button.setBounds(w - BTN_W_SMALL - 60, y_small, BTN_W_SMALL, BTN_H_SMALL); // Debug button
        }
        // Position the start button at the center-bottom of the panel.
        x_start = (w - BTN_W_BIG) / 2; // Calculate the horizontal position for the start button.
        y_start = y_small - (BTN_H_BIG - BTN_H_SMALL) / 2 - 20; // Adjust the vertical position for the start
                                                                // button.
        start_button.setBounds(x_start, y_start, BTN_W_BIG, BTN_H_BIG); // Set the bounds for the start button.
    }
}