Undecorated jframe resize problem

Question

i created a custom jframe look by setting a jframe to undecorated and designing my own maximize/minimize/close buttons and other things to improve its appearence
the problem is that when set to undercorated all the default resizing/move methods are gone
i tried implementing my own resize methods, they seem to work but it flashes like crazy while resizing
anyone have any idea how to stop all the flashing or a better way to implement this?
the following is a small example of the problem i am having, i only implemented the north resize part so the code can be easier to read.
thnx in advance
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.imageio.*;
import java.io.*;
import java.awt.image.BufferedImage;
public class TestFrame extends JFrame implements MouseMotionListener, MouseListener
     Point sp;
     int     compStartHeight;
     int minHeight = 100;
     JPanel frameContent = new JPanel();
     public TestFrame()
          super("testing frame");
          setSize(600, 600);
          setContentPane(frameContent);
          frameContent.setBackground(Color.black);
          frameContent.setLayout(new BoxLayout(frameContent, BoxLayout.Y_AXIS));     
          setUndecorated(true);
          addMouseMotionListener(this);
          addMouseListener(this);
          JButton testButton = new JButton("TEST");
          JButton testButton2 = new JButton ("TEST2");
          frameContent.add(testButton);
          frameContent.add(Box.createVerticalGlue());
          frameContent.add(testButton2);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          setVisible(true);
     public void mouseMoved(MouseEvent e)
          Point p = e.getPoint();
          if (p.y > e.getComponent().getSize().height - 5)
               setCursor( Cursor.getPredefinedCursor( Cursor.N_RESIZE_CURSOR ));
          else
               setCursor( Cursor.getPredefinedCursor( Cursor.DEFAULT_CURSOR));
     public void mouseDragged(MouseEvent e)
          Point p = e.getPoint();
          int compWidth = getSize().width;
          if (getCursor().getType() == Cursor.N_RESIZE_CURSOR)
               int nextHeight = compStartHeight+p.y-sp.y;
               if (nextHeight > minHeight)
                    setSize(compWidth,nextHeight);
                    validate();
          else
               int x = getX()+p.x-sp.x;     
               int y = getY()+p.y-sp.y;     
               setLocation(x,y);
     public void mousePressed(MouseEvent e)
          sp = e.getPoint();
          compStartHeight = getSize().height;
     public void mouseEntered(MouseEvent e)
    public void mouseExited(MouseEvent e)
          if (sp == null)
               setCursor( Cursor.getPredefinedCursor( Cursor.DEFAULT_CURSOR));
    public void mouseClicked(MouseEvent e)
    public void mouseReleased(MouseEvent e)
          sp = null;
     public static void main(String[] args)
     new TestFrame();
}

Answer 1

I doubt there is a faster / easier way to resize.
Have you tried adding
public boolean isDoubleBuffered()
  return true;
}To over-ride Component.isDoubleBuffered. This should sort out your flickering problem.
Bamkin