Apply Image as background to JPanel [RESOLVED]

[Ruku]

How can I apply an image as a background to a JPanel? I can do this fine with the graphic object, but it's drawing is temporary... so I thought of getting to do a new class extending JPanel...

what I got so far is this:

package rukupaint;
import javax.swing.*;
import java.awt.*;
import java.util.*;

public class clsPaintPanel extends JPanel {
    
    /** Creates a new instance of clsPaintPanel */
    public clsPaintPanel() {
    }

    protected void paintComponent (Graphics g) {
        super.paintComponent (g);

        if (this.image != null) {
            Graphics2D g2d = (Graphics2D) g;
            int iw = this.image.getWidth(this);
            int ih = this.image.getHeight(this);
            int w = iw != 0 ? iw : 1;
            int h = ih != 0 ? ih : 1;
            double sx = ((double) getWidth()) / ((double) w);
            double sy = ((double) getHeight()) / ((double) h);
            AffineTransform at = new AffineTransform ();

            if (this.maintainAspectRatio) {
                sx = sy = Math.max(sx, sy);
            }
            
            at.scale(sx, sy);
            g2d.drawImage(this.image, at, this);
        }
    }
}

I've seen this on another forum, I do not claim the code to be mine, I just need to understand how to logically solve my problem...

But there doesn't seem to be an "image" property to the JPanel...

help on this would be appreciated!!!

(By the way if there is some object I havn't seen that runs a background picture property, don't hesitate sharing the class/object, thx!!!)

[ComputerJy]

you should add

private Image image;
    private boolean maintainAspectRatio;

[System_Error]

How can I apply an image as a background to a JPanel? I can do this fine with the graphic object, but it's drawing is temporary... so I thought of getting to do a new class extending JPanel...

what I got so far is this:

package rukupaint;
import javax.swing.*;
import java.awt.*;
import java.util.*;

public class clsPaintPanel extends JPanel {
    
    /** Creates a new instance of clsPaintPanel */
    public clsPaintPanel() {
    }

    protected void paintComponent (Graphics g) {
        super.paintComponent (g);

        if (this.image != null) {
            Graphics2D g2d = (Graphics2D) g;
            int iw = this.image.getWidth(this);
            int ih = this.image.getHeight(this);
            int w = iw != 0 ? iw : 1;
            int h = ih != 0 ? ih : 1;
            double sx = ((double) getWidth()) / ((double) w);
            double sy = ((double) getHeight()) / ((double) h);
            AffineTransform at = new AffineTransform ();

            if (this.maintainAspectRatio) {
                sx = sy = Math.max(sx, sy);
            }
            
            at.scale(sx, sy);
            g2d.drawImage(this.image, at, this);
        }
    }
}

I've seen this on another forum, I do not claim the code to be mine, I just need to understand how to logically solve my problem...

But there doesn't seem to be an "image" property to the JPanel...

help on this would be appreciated!!!

(By the way if there is some object I havn't seen that runs a background picture property, don't hesitate sharing the class/object, thx!!!)

You paint the image... Simply add this class and use it in your other class.

[Ruku]

Still can't solve this, sorry if I've been unclear... What I want is just to draw an image that sticks to the object... such as .net's picturebox...

since there is no picturebox in Java I thought of using a jPanel, but when I move a window over what I've drawned the image disapears!

So how can I do this sticky image thing?




To ComputerJy: My class is working, yeah I forgot some declarations in the code i've pasted...!!

To System_Error: I did, but what happens is that all my image gets white and nothing is drawned... o_O

[ComputerJy]

I found this link. it might be usefull

[Ruku]

thx for the link... but I don't understand what exacly makes the image sticky within the paintComponent(Graphics g) sub.... o_O

(Graphics2D g2d = (Graphics2D) g

looks like the 2 most important lines are:

super.paintComponent(g);
g2d.drawImage(this.image, at, this);

buuut it doesn't quite work... nothing gets drawned...

[ComputerJy]

Did you change the file name?

[Ruku]

uh, no, what filename?

I got my class with the constructor working well...

the only thing I didn't get is that ImageFill class within the link you gave me... can't find it... and I've imported everythin' they did...

[ComputerJy]

In their code, the image is captured from a file "background.jpg" in the constructor, make sure you change that file to a valid image file.

[Ruku]

    protected void paintComponent(Graphics g) {
        try {
            super.paintComponent(g);
            g.drawImage(image, 0, 0, this);
        }
        catch (Exception ex) {
        }
    }

got everything working...!

I just needed to call the repaint(); method and everything was good!!!