Java JPanel tiled background image

Question

I currently have the code for creating a JOptionPane that tiles an image to the background no matter the size I set it to :)

package test;
import java.awt.*;  
import java.awt.image.BufferedImage;  
import java.io.*;  
import javax.imageio.ImageIO;  
import javax.swing.*;  

public class TiledImage extends JPanel {  
    BufferedImage tileImage;  


    public TiledImage(BufferedImage image) {  
        tileImage = image;  
    }  

    protected void paintComponent(Graphics g) {  
        int width = getWidth();  
        int height = getHeight();  
        for (int x = 0; x < width; x += tileImage.getWidth()) {  
            for (int y = 0; y < height; y += tileImage.getHeight()) {  
                g.drawImage(tileImage, x, y, this);  
            }  
        }  
    }  

    public Dimension getPreferredSize() {  
        return new Dimension(240, 240);  
    }  

    public static void main(String[] args) throws IOException {  
        BufferedImage image = ImageIO.read(new File("./resource/patterngrey.png"));  
        TiledImage test = new TiledImage(image);  
        JOptionPane.showMessageDialog(null, test, "", JOptionPane.PLAIN_MESSAGE);  
    }  
} 

the problem I am having is using the same code to add an image to a JPanel background in a JFrame here is what I have:

package test;
import java.awt.*;  
import java.awt.image.BufferedImage;  
import java.io.*;  
import javax.imageio.ImageIO;  
import javax.swing.*;  

public class TiledImage extends JPanel {  
    BufferedImage tileImage;  
    static JFrame mainFrame = new JFrame("Program Name");
    static JPanel userDetailsPanel = new JPanel();

    public TiledImage(BufferedImage image) {  
        tileImage = image;  
    }  

    protected void paintComponent(Graphics g) {  
        int width = getWidth();  
        int height = getHeight();  
        for (int x = 0; x < width; x += tileImage.getWidth()) {  
            for (int y = 0; y < height; y += tileImage.getHeight()) {  
                g.drawImage(tileImage, x, y, this);  
            }  
        }  
    }  


    public static void main(String[] args) throws IOException {  
        mainFrame.setSize(400,400);
        mainFrame.setLayout(new BorderLayout());
        mainFrame.add(userDetailsPanel, BorderLayout.CENTER);
        BufferedImage image = ImageIO.read(new File("./resource/patterngrey.png"));  
        TiledImage backgroundImage = new TiledImage(image);  
   //   userDetailsPanel.setComponent(backgroundImage); //i know this line is wrong 
   //but i dont know how to correct it
        mainFrame.setVisible(true);
    }  
} 

Any and all help is appreciated if there is a better way of doing it that is a lot less code that would also be great. I do need to add labels and buttons on top of the background once i have my background sorted.

The background needs to be tiled as the application will have a couple of different JPanels in the JFrame with different pattern backgrounds and i would like to make the frame resizable

Answer 1

An instance of java.awt.TexturePaint provides a convenient way to tile a BufferedImage. Related examples may be seen here. Given a TexturePaint, you can fill a component's background fairly easily, as shown here.

    private TexturePaint paint;

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setPaint(paint);
        g2d.fillRect(0, 0, getWidth(), getHeight());
    }

Answer 2

You state:

Any and all help is appreciated if there is a better way of doing it that is a lot less code that would also be great.

That's not a lot of code actually. The only thing else I could suggest is that if the JPanel is not going to vary in size, create a background BufferedImage, draw your tiled images in that, and then draw the one background image in either your JPanel's paintComponent method, or in a JLabel's icon. If you go the latter route, then give the JLabel a layout manager so that it can act as a well-behaved container for your components. And make sure that anything on top of your tiled containers is not opaque if the image needs to show through, especially JPanels.