GUI not loading but seems to be running

Question

Problem

When I am starting the PetUI main class from the actionPerformed function in my StartGUI class, the PetUI dialog does not start with anything on the screen but it seems to be running in the background. For debugging purposes, the pet will die within a few seconds. Once the pet dies, the screen updates and you can see the correct screen until you press OK and it will load the StartGUI class again so you can make a new pet and start over.

Note

When I run the PetUI main directly from the IDE, it loads correctly and follows out all functions without error.

Images:

When starting from StartGUI class:

The dialog on the left is the StartGUI class, and then one on the right is the PetUI class started from the StartGUI class.

After Pet Death:

Now that the pet is dead, you can simply see that the PetUI class has updated its dialog, and you can see what is correctly supposed to be shown.

Running PetUI directly from IDE (IntelliJ Idea)

Now you can see that it works and does it's function correctly.

Code

PetUI Class:

package vps.main.gui;

import vps.main.Pet;
import vps.util.io;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

/**
 * Created by XXXX on 3/23/2016.
 */
public class PetUI extends JFrame implements ActionListener {
    public static Pet mainPet = new Pet("Unknown Pet", 100, 100, 100, 100);
    static JProgressBar healthBar = new JProgressBar(0, 100);
    static JProgressBar hungerBar = new JProgressBar(0, 100);
    static JProgressBar happinessBar = new JProgressBar(0, 100);
    static JLabel foodCount = new JLabel();
    static JLabel medpackCount = new JLabel();
    static int medpacks = 10;
    static int food = 25;
    static JMenuBar menuBar = new JMenuBar();
    JLabel petInfo = new JLabel("Name:" + mainPet.getName() + " | Age: "+mainPet.getAge());
    JMenu file = new JMenu("File");
    JMenuItem save = new JMenu("Save");
    JButton healButton = new JButton("", new ImageIcon("src\\vps\\files\\ambulanceIcon.png"));
    JButton feedButton = new JButton("", new ImageIcon("src\\vps\\files\\feedIcon.png"));
    JButton playButton = new JButton("", new ImageIcon("src\\vps\\files\\playIcon.png"));
    JButton quitButton = new JButton("", new ImageIcon("src\\vps\\files\\quitIcon.png"));
    JPanel buttons = new JPanel();
    JPanel bars = new JPanel();

    public PetUI() {
        super("Pet UI");
        setLayout(new FlowLayout());
        buttons.add(healButton);
        buttons.add(feedButton);
        buttons.add(playButton);
        buttons.add(quitButton);
        bars.add(healthBar);
        bars.add(hungerBar);
        bars.add(happinessBar);
        happinessBar.setStringPainted(true);
        hungerBar.setStringPainted(true);
        healthBar.setStringPainted(true);
        happinessBar.setString("Happiness");
        hungerBar.setString("Hunger");
        healthBar.setString("Health");
        healButton.setBorderPainted(false);
        healButton.setContentAreaFilled(false);
        healButton.setFocusPainted(false);
        feedButton.setBorderPainted(false);
        feedButton.setContentAreaFilled(false);
        feedButton.setFocusPainted(false);
        playButton.setBorderPainted(false);
        playButton.setContentAreaFilled(false);
        playButton.setFocusPainted(false);
        quitButton.setBorderPainted(false);
        quitButton.setContentAreaFilled(false);
        quitButton.setFocusPainted(false);
        playButton.addActionListener(this);
        healButton.addActionListener(this);
        feedButton.addActionListener(this);
        quitButton.addActionListener(this);
        save.addActionListener(this);
        add(petInfo);
        add(medpackCount);
        add(buttons);
        add(foodCount);
        add(bars);
        menuBar.add(file);
        file.add(save);


    }

    public static int getMedpacks() {
        return medpacks;
    }

    public static void setMedpacks(int medpacks) {
        PetUI.medpacks = medpacks;
    }

    public static void main(String[] args) {
        PetUI p = new PetUI();
        p.setJMenuBar(menuBar);
        p.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        p.setSize(640, 480);
        p.setVisible(true);
        while (true) {
            happinessBar.setValue((int) Math.round(mainPet.getHappiness()));
            healthBar.setValue((int) Math.round(mainPet.getHealth()));
            hungerBar.setValue((int) Math.round(mainPet.getHunger()));
            mainPet.setHappiness(mainPet.getHappiness() - 0.1);
            mainPet.setHunger(mainPet.getHunger() - 0.5);
            //color set
            /**
             * if val greater than 75 = great
             * if val less than 75 = good
             * if val less than 50 = OK
             * if val less than 25 = bad
             * if val less than or equ 0 = dead/horrible
             */

            if (mainPet.getHappiness() > 75) {
                happinessBar.setString("Ecstatic");
                happinessBar.setForeground(Color.green);
            }
            if (mainPet.getHappiness() <= 75) {
                happinessBar.setString("Happy");
                happinessBar.setForeground(Color.magenta);
            }
            if (mainPet.getHappiness() <= 50) {
                happinessBar.setString("OK");
                happinessBar.setForeground(Color.orange);
            }
            if (mainPet.getHappiness() <= 25) {
                happinessBar.setString("Sad");
                happinessBar.setForeground(Color.red);
            }
            if (mainPet.getHappiness() <= 0) {
                happinessBar.setString("Horrible");
                happinessBar.setForeground(Color.black);

            }

            if (mainPet.getHealth() > 75) {
                healthBar.setString("Great");
                healthBar.setForeground(Color.green);
            }
            if (mainPet.getHealth() <= 75) {
                healthBar.setString("Good");
                healthBar.setForeground(Color.magenta);
            }
            if (mainPet.getHealth() <= 50) {
                healthBar.setString("OK");
                healthBar.setForeground(Color.orange);
            }
            if (mainPet.getHealth() <= 25) {
                healthBar.setString("Requires attention");
                healthBar.setForeground(Color.red);
            }
            if (mainPet.getHealth() <= 0) {
                    healthBar.setString("Death");
                    healthBar.setForeground(Color.black);
                    JOptionPane.showMessageDialog(null, "Your pet: " + mainPet.getName() + " has died.");
                p.dispose();
                StartGUI.main(null);
                break;



            }

            if (mainPet.getHunger() > 75) {
                hungerBar.setString("Full");
                hungerBar.setForeground(Color.green);
            }
            if (mainPet.getHunger() <= 75) {
                hungerBar.setString("Great");
                hungerBar.setForeground(Color.magenta);
            }
            if (mainPet.getHunger() <= 50) {
                hungerBar.setString("Hungry");
                hungerBar.setForeground(Color.orange);
            }
            if (mainPet.getHunger() <= 25) {
                hungerBar.setString("Empty");
                hungerBar.setForeground(Color.red);
            }
            if (mainPet.getHunger() <= 0) {
                hungerBar.setString("Starving");
                hungerBar.setForeground(Color.black);
            }


            //death values
            if (mainPet.getHunger() <= 5) {
                mainPet.setHealth(mainPet.getHealth() - 1);
            }
            if (mainPet.getHealth() <= 45) {
                mainPet.setHappiness(mainPet.getHappiness() - 1);
            }

            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }


    public static int getFood() {
        return food;
    }

    public static void setFood(int food) {
        PetUI.food = food;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == quitButton) {
            int quit = JOptionPane.showConfirmDialog(null, "Are you sure you want to quit?");
            if (quit == 0) {
                System.exit(0);
            } else {
                //do nothing, just stay
            }
        } else if (e.getSource() == feedButton) {
            if (getFood() <= 0) {
                JOptionPane.showMessageDialog(null, "You are out of food.");
            } else if (mainPet.getHunger() > 100) {
                JOptionPane.showMessageDialog(null, "You do not need food right now.");
            } else {
                mainPet.setHunger(mainPet.getHunger() + 20);
                setFood(getFood() - 1);

            }
        } else if (e.getSource() == healButton) {
            if (getMedpacks() <= 0) {
                JOptionPane.showMessageDialog(null, "You are out of medpacks.");
            } else if (mainPet.getHealth() > 100) {
                JOptionPane.showMessageDialog(null, "You do not need a medpack right now.");
            } else {

               if(mainPet.getHealth() + 20 >= 100) {
                   JOptionPane.showMessageDialog(null, "You do not need a medpack right now.");
               }
                else {
                   setMedpacks(getMedpacks() - 1);
               }
            }

        }
        else if(e.getSource() == save) {
            io.replaceMainPet("");
        }

    }
}

StartGUI Class:

package vps.main.gui;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import vps.util.io;
import vps.util.io.*;
/**
 * Created by XXX on 3/25/2016.
 */
public class StartGUI extends JFrame implements ActionListener {
    public static String readPath = "";
    static JMenuBar menuBar = new JMenuBar();
    JLabel vpstitle = new JLabel("VPS Alpha 1.2",JLabel.CENTER);
    JMenu fileMenu = new JMenu("File");
    JMenuItem newSave = new JMenuItem("New Save");
    JMenuItem openSave = new JMenuItem("Open Save");
    JButton play = new JButton("Play");
    JButton help = new JButton("Help");

    public StartGUI() {
        super("Startup");
        setLayout(new GridLayout(3,3));
        add(vpstitle);
        add(play);
        add(help);
        play.addActionListener(this);
        menuBar.add(fileMenu);
        fileMenu.add(newSave);
        fileMenu.add(openSave);
        newSave.addActionListener(this);
        openSave.addActionListener(this);
        vpstitle.setFont(new Font ("Segoe Print", Font.BOLD , 72));

    }
    public static void main(String[] args) {
        StartGUI s = new StartGUI();
        s.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        s.setSize(720,480);
        s.setJMenuBar(menuBar);
        s.setVisible(true);
    }

    public static String getReadPath() {
        return readPath;
    }

    public static void setReadPath(String readPath) {
        StartGUI.readPath = readPath;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if(e.getSource() == play) {
            try {
                if (readPath.equalsIgnoreCase("")) {
                    JOptionPane.showMessageDialog(null, "Please select a save file.\nFile --> Open Save / New Save");

                }
                else {
                    PetUI.main(null);
                }
            }
                catch(NullPointerException n) {
                    JOptionPane.showMessageDialog(null,"You didn't choose a file.");
                }
            }
        else if(e.getSource() == newSave) {
            String saveName = JOptionPane.showInputDialog(null,"Please name this save file:");
            JOptionPane.showMessageDialog(null,"Select your new save directory.");
            JFileChooser jf = new JFileChooser();
            jf.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
            jf.showOpenDialog(null);
            readPath = jf.getSelectedFile().getAbsolutePath()+"\\"+ saveName+".bin";
            io.write(readPath);
            io.replaceMainPet(readPath);
        } else if (e.getSource() == openSave) {
            JOptionPane.showMessageDialog(null,"Press OK to select your previous save file.");
            JFileChooser jf = new JFileChooser();
            jf.showOpenDialog(null);
            readPath = jf.getSelectedFile().getAbsolutePath();
            io.replaceMainPet(readPath);
        }
        }
    }

Answer 1

Place your game loop into a thread. It is doing your game logic instead of updating the swing gui which is why you need to split them up. I would also suggest adding a boolean method to Pet.java as isAlive() so that when your pet dies or when the game is over the thread will die. For example in PetUI.java:

public static void main(String[] args) {
    PetUI p = new PetUI();
    p.setJMenuBar(menuBar);
    p.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    p.setSize(640, 480);
    p.setVisible(true);
    Thread game = new Thread(new Runnable(){
        public void run() {
            while (true) { // while(mainPet.isAlive())
                happinessBar.setValue((int) Math.round(mainPet.getHappiness()));
                healthBar.setValue((int) Math.round(mainPet.getHealth()));
                hungerBar.setValue((int) Math.round(mainPet.getHunger()));
                mainPet.setHappiness(mainPet.getHappiness() - 0.1);
                mainPet.setHunger(mainPet.getHunger() - 0.5);
                // the rest of your game method
            }
        }
    }
    game.start();
}