fixing JScrollPane with JLabel

Question

In order to add a background Image , I work on JLabels instead of JPanel .

    JFrame frame=new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JLabel label=new JLabel(new ImageIcon("bg.png"));
    label.setLayout(new BoxLayout(label, BoxLayout.Y_AXIS));
    for(int i=0;i<20;i++)
         label.add(new JLabel(i.toString()));
    frame.add(label);

the problem here is that only components that fit the background image will be shown (in my example only the 10 first JLabels)

I tried using a JScrollPane

    JScrollPane scroll=new JScrollPane(l);
    for(int i=0;i<20;i++)
         label.add(new JLabel(i.toString()));
    frame.add(scroll);

but it didn't change much , so I tried using a JPanel

    JPanel panel=new JPanel();
    panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
    JScrollPane scroll=new JScrollPane(panel);
    for(int i=0;i<20;i++)
         panel.add(new JLabel(i.toString()));
    label.add(scroll);
    frame.add(label);

so I got the JScrollPane working properly but the JPanel has covered the background image

what should I do ?

Here's the result to adding JLabels to label:

The result after adding them to the scroll:

And after adding setOpaque(false) to the JPanel:

set the `JPanel`'s opaque to false. But, for better help sooner please post a [mcve] and ASCII art / image of what you have and what you want to achieve, this will improve your post a lot. As you don't have enough reputation yet, you can add a link to your image and we can edit the post and make it show here — Frakcool, Sep 13 '16 at 17:43
Also, as an aside recommendation, make your variables more descriptive, `l` what is `l`? I had to go up in the code to know what it was, instead call them `label` or `pane` / `panel` for the panels, `s` change it to `scroll` / `scrollPane` / etc; it will make the code easier to read and understand for you and for us — Frakcool, Sep 13 '16 at 17:51
Well, then post a runnable example, the image, and follow my 2nd comment recommendations when doing so, so we can give more help — Frakcool, Sep 13 '16 at 17:53
well here's the result to adding JLabels to label http://imgur.com/W0xMDdl here's the result to adding them to scroll http://imgur.com/FOEf9M4 and here's when I set panel opaque to false http://imgur.com/TIlhgPS — Ghassen Tounsi, Sep 13 '16 at 21:53
And where's the [mcve]? You forgot to add it, please [edit] your question when you have done it and include the images there :) — Frakcool, Sep 13 '16 at 21:59

score 4 · Accepted Answer · edited Jun 20 '20 at 09:12

You can add the image as part of the JPanel's paintComponent() method, then add the labels above it, then put that pane inside a JScrollPane and finally add it to the JFrame, for example:

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;

public class PanelWithBackgroundImage {
    
    private JFrame frame;
    private JPanel pane;
    private Image img;
    private JScrollPane scroll;
    
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            
            @Override
            public void run() {
                new PanelWithBackgroundImage().createAndShowGui();
            }
        });
    }
    
    public void createAndShowGui() {
        frame = new JFrame("JFrame with bg example");
        try {
            img = ImageIO.read(new FileInputStream("/home/jesus/Pictures/tokyo.jpg"));
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        pane = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
            }
        };
        
        pane.setLayout(new BoxLayout(pane, BoxLayout.PAGE_AXIS));
        
        for (int i = 0; i < 20; i++) {
            pane.add(new JLabel("label " + i));
        }
        
        scroll = new JScrollPane(pane);
        
        frame.add(scroll);
        frame.setSize(frame.getPreferredSize());
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

Which gives the following output:

If you want the JLabels centered, you can change the for loop with:

for (int i = 0; i < 20; i++) {
    JLabel label = new JLabel("label " + i);
    label.setAlignmentX(Component.CENTER_ALIGNMENT);
    pane.add(label);
}

Which should look similar to this:

Note:

You can copy-paste the code above, it should work, just change the image path, and that code, is called a Minimal, Complete and Verifiable Example (MCVE), next time, please post one which demonstrates what you have tried, not only parts of it, this way you'll get more, better and faster answers. Help us to help you! :)

fixing JScrollPane with JLabel

1 Answers1

Note:

Linked