Настройка JScrollPane при зуме в JPanel

this.setPreferredSize(new Dimension((int)(this.width*tx.getScaleX()),(int)(this.height*tx.getScaleY())));

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import java.awt.geom.Point2D;
import static java.awt.Color.*;
class TestZoomPanel extends JPanel implements Runnable {
    Graphics2D window;
    AffineTransform gmatrix = new AffineTransform();
    private double valScale;
    private int width = 1024;
    private int height = 720;
    private JFrame Frame;
    private JScrollPane Scroll;
 
    public TestZoomPanel() {
        this.addMouseWheelListener(new ZoomHandler());
    }
 
    @Override
    public void paint(Graphics g) {
        super.paint(g);
        this.setPreferredSize(new Dimension((int) (this.width * gmatrix.getScaleX()), (int) (this.height * gmatrix.getScaleY())));
        window = (Graphics2D) g;
        window.setColor(Color.RED);
        window.setTransform(gmatrix);
        window.setColor(Color.BLUE);
        draw();
    }
 
    public void run() {
        JFrame frame = new JFrame("TestZum");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(this);
        frame.setSize(width, height);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        this.setPreferredSize(new Dimension(3000, 3000));
        JScrollPane mainPane = new JScrollPane(this);
        mainPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        mainPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        frame.add(mainPane, BorderLayout.CENTER);
        this.Frame = frame;
        this.Scroll = mainPane;
 
 
    }
 
    public void draw() {
        window.setTransform(gmatrix);
        window.setColor(black);
        window.fillOval(500, 500, 350, 350);
    }
 
    private class ZoomHandler implements MouseWheelListener {
 
        double scale = 1.0;
 
        public void mouseWheelMoved(MouseWheelEvent e) {
            if (e.getScrollType() == MouseWheelEvent.WHEEL_UNIT_SCROLL) {
 
                Point2D point1 = e.getPoint();
                Point2D point2 = null;
                try {
                    point2 = gmatrix.inverseTransform(point1, null);
                } catch (NoninvertibleTransformException ex) {
                    ex.printStackTrace();
                    return;
                }
 
                scale -= (0.1 * e.getWheelRotation());
                scale = Math.max(0.1, scale);
                valScale = scale;
                gmatrix.setToIdentity();
                gmatrix.translate(point1.getX(), point1.getY());
                gmatrix.scale(scale, scale);
                gmatrix.translate(-point2.getX(), -point2.getY());
 
                TestZoomPanel.this.revalidate();
                TestZoomPanel.this.repaint();
            }
        }
    }
 
}
 
public class TestZoom {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new TestZoomPanel());
    }
}