How to write a scrollable JDesktopPane?

you want to create scorllable JDesktopPane, (so that when some internal frames get out of the screen JDesktopPane adds scrollers to itself) or ?

Yes, that's what I want. But I have solve this problem. I have another question, is it possible to create graphical components of arbitrary shape? What I want is to a line shape. I need to display a lot of lines in the panel and each line is an object so I can click on them, for example. But if I use Canvas, I'm afraid the rectangle shape of canvas will cause the lines block each other.
Thank you for your attention. I will pass the points to you if you'd like to give comments on this problem.

check this question (and my comments there) - it is open. maybe this is what you want - i don't know.
https://www.experts-exchange.com/topics/comp/lang/java/Q.10110666

can you (please :) post some (little) working example about scrollable JDesktopPane? this question was discussed a long ago at DukeDollars forum (Javasoft web site) and there was partially solution there (i was going to give you the URL when you define more precisely your question:))

merry christmas
  heyhey

Thank you for your comment! I solve the problem by using setPreferedSize of the JDesktopPane.

import java.applet.Applet;
import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;

public class WorkPane extends JDesktopPane implements Scrollable, MouseMotionListener{
      public WorkPane(){
            setLayout(null);
            setPreferredSize(new Dimension(1000,1000));
            addMouseMotionListener(this);
      }
      

    public Dimension getPreferredScrollableViewportSize() {
        return getPreferredSize();
    }

    public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {

        int currentPosition = 0;
        if (orientation == SwingConstants.HORIZONTAL)
            currentPosition = visibleRect.x;
        else
            currentPosition = visibleRect.y;

        if (direction < 0) {
            int newPosition = currentPosition - (currentPosition / maxUnitIncrement) * maxUnitIncrement;
            return (newPosition == 0) ? maxUnitIncrement : newPosition;
        } else {
            return ((currentPosition / maxUnitIncrement) + 1) * maxUnitIncrement - currentPosition;
        }
    }

    public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
        if (orientation == SwingConstants.HORIZONTAL)
            return visibleRect.width - maxUnitIncrement;
        else
            return visibleRect.height - maxUnitIncrement;
    }

    public boolean getScrollableTracksViewportWidth() {
        return false;
    }

    public boolean getScrollableTracksViewportHeight() {
        return false;
    }
  }

then I use a JScrollPane to display it.
Please post an anwser so that I can pass you the points.

a haven't helped you so much :)
if you want, you can delete the question and get back your points.
if you think that i've really helped you, then i'll post an answer.