trouble in wrapping a JPanel into a JScrollPane

[Esmaeil Ashrafi]

Hi guys
i write a SSCCE ( actually i hope to be , if not,please let me know ) to demonstrate the problem i found to wrapping a JPanel into a JScrollPane that located within a frame :

  import java.awt.BorderLayout;
import javax.swing.*;

class ScrollTest extends JFrame {

    ScrollTest() {
        JPanel bigPanel = new JPanel();
        JPanel smallPanel = new JPanel();
        JPanel main = new JPanel(new BorderLayout());
        this.getContentPane().add(new JScrollPane(main));
        main.add(bigPanel, "Center");
        main.add(smallPanel, "South");
        main.add(new JScrollPane(bigPanel));
        bigPanel.setPreferredSize(new java.awt.Dimension(400, 300));
        smallPanel.setPreferredSize(new java.awt.Dimension(400, 100));
    }

    public static void main(String args[]) {
        ScrollTest frame = new ScrollTest();
        frame.setSize(400, 400);
        frame.setVisible(true);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(2);
    }
}
  

line #13

I want scroll bars be appeared over the "bigPanel" when necessary ;

Maybe it is not possible ! or maybe i don't know how to

thanks in advance

[Michael Dunn]

the scrollpane needs to have a preferredSize set as well

run this, then scroll down to see the inner scrollpane

    
import java.awt.BorderLayout;
import javax.swing.*;

class ScrollTest extends JFrame {

    ScrollTest() {
        JPanel bigPanel = new JPanel();
        JPanel smallPanel = new JPanel();
        JPanel main = new JPanel(new BorderLayout());
        this.getContentPane().add(new JScrollPane(main));
        //main.add(bigPanel, "Center");//<----not needed
        main.add(smallPanel, "South");
        
        //main.add(new JScrollPane(bigPanel));
        JScrollPane sp = new JScrollPane(bigPanel);
        sp.setPreferredSize(new java.awt.Dimension(600, 400));
        main.add(sp);
        
        //bigPanel.setPreferredSize(new java.awt.Dimension(400, 300));
        bigPanel.setPreferredSize(new java.awt.Dimension(800, 600));//<---increased size to ensure they work
        smallPanel.setPreferredSize(new java.awt.Dimension(400, 100));
    }

    public static void main(String args[]) {
        ScrollTest frame = new ScrollTest();
        frame.setSize(400, 400);
        frame.setVisible(true);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(2);
    }
}

[Esmaeil Ashrafi]

I think this forum lack just one thing :

"A button in every posted message area to get thanks from visitors"

to prevent someone like me to post a reply just to say thank you very much

[Rob Spoor]

We don't mind. In fact, we encourage it. But we also have the "Mark as Resolved" button at the bottom, with the little .