java - JButtons won't update on button click

Question

Currently displays a GUI with an 8x8 grid of randomized colored buttons. The newButton is to reset the score display to 0 and reset the grid with a fresh like it does on startup after being clicked. I haven't been able to find many solutions other than that it's to do with the way Java displays it's buttons and the way layering works. Here are the 2 classes I'm using.

import javax.swing.JFrame; 
import javax.swing.*;
import java.awt.event.*;
import javax.swing.JPanel;
import java.awt.Color;

public class ShinyButtonsApp extends JFrame implements ActionListener {

    private static byte ROWS = 8;
    public int useThis; 
    ShinyButtons shiny = new ShinyButtons();
    public static ImageIcon[] icons = {new ImageIcon("RedButton.png"),
                                       new ImageIcon("OrangeButton.png"), 
                                       new ImageIcon("YellowButton.png"), 
                                       new ImageIcon("GreenButton.png"), 
                                       new ImageIcon("BlueButton.png"), 
                                       new ImageIcon("LightGrayButton.png"), 
                                       new ImageIcon("DarkGrayButton.png")}; 


    public ShinyButtonsApp(String title) { 
        super(title); // Set title of window 
        setDefaultCloseOperation(EXIT_ON_CLOSE); // allow window to close 
        setSize(578, 634); // Set size of window 
        setResizable(false);

        getContentPane().setLayout(null);   

        JLabel aLabel = new JLabel("Score: "); 
        aLabel.setLocation(10, 570); 
        aLabel.setSize(80,30); 
        getContentPane().add(aLabel);

        JTextField scoreField = new JTextField(); 
        scoreField.setText(Integer.toString(shiny.score));
        scoreField.setEditable(false);
        scoreField.setHorizontalAlignment(JTextField.RIGHT);
        scoreField.setLocation(60, 570); 
        scoreField.setSize(120,30);
        scoreField.setBackground(Color.WHITE); 
        getContentPane().add(scoreField);

        JButton newButton = new JButton("New Game");
        newButton.addActionListener(this);
        newButton.setLocation(348,570);
        newButton.setSize(110,30);
        getContentPane().add(newButton);

        JButton quitButton = new JButton("Quit");
        quitButton.setLocation(468,570);
        quitButton.setSize(80,30);
        getContentPane().add(quitButton);

        resetButtons2();
    } 

    public void actionPerformed(ActionEvent e) {
                shiny.score = 0;
                shiny.resetButtons();
                resetButtons2();
    }

    public void resetButtons2() {
        for (int r=0; r<ROWS; r++) {
            for (int c=0; c<ROWS; c++) {
                ImageIcon image1 = icons[(int)shiny.getButton(r,c)];
                JButton button = new JButton(image1);
                button.setLocation(10+(69*r),10+(69*c));
                button.setSize(69,69);
                button.setBorder(BorderFactory.createLineBorder(Color.GRAY,1));
                getContentPane().add(button);
            }
        }
    }

    public static void main(String[] args) { 
        ShinyButtonsApp frame;      
        frame = new ShinyButtonsApp("Shiny Buttons"); // Create window 
        frame.setVisible(true); // Show window      
    }   
}

and

import javax.swing.JFrame; 
import javax.swing.*;
import java.awt.event.*;
import javax.swing.JPanel;
import java.awt.Color;

public class ShinyButtons extends JPanel{ 
    public static byte RED = 0; 
    public static byte ORANGE = 1; 
    public static byte YELLOW = 2; 
    public static byte GREEN = 3; 
    public static byte BLUE = 4; 
    public static byte LIGHT_GRAY = 5; 
    public static byte DARK_GRAY = 6; 

    public static byte ROWS = 8; 

    public byte[][] buttonTable;

    public int score = 0; 

    public ShinyButtons() { 
        buttonTable = new byte[ROWS][ROWS]; 
        resetButtons(); 
    } 

    public void resetButtons() { 
        for (int r=0; r<ROWS; r++) 
            for (int c=0; c<ROWS; c++) 
                buttonTable[r][c] = (byte)(Math.random()*7); 
    } 

    public byte getButton(int r, int c) { return buttonTable[r][c]; } 

    public int getScore() { return score; }
} 

Answer 1

You are creating a new set of buttons in resetButtons2() and placing them on top (or rather under) of the already existing set of buttons in the same locations. You should create the set of buttons once and only update their icons upon reset.

You should do a number of things:

• Use a proper layout manager, e.g., GridLayout
• Create the 8x8 grid of buttons only once and replace their icons when needed
• Call invalidate/repaint to refresh the content pane

And for a JFrame you don't need getContentPane().add(...), you can directly do add(...)