Problems painting a JPanel component on a JFrame

Question

Hi.
I've built a subclass of JPanel that has some controls on it, such as JPanels, JCheckBoxes, images, etc. I need to repaint this JPanel periodically because its contents are constantly changing.
I have it added to a main JFrame (this JFrame has also other JPanels in other locations of its content pane), and when I try to repaint this JPanel, it does not seem to be double buffered, because it momentaneously repaints other parts of the window into the JPanel region, and after that it repaints what it should.
I have tested a Panel instead of a JPanel to do the same task, and the Panel works fine.
Basically, the code is:
public class MyFrame extends JFrame
JPanel myPanel = new JPanel();
JPanel myPanel2 = new JPanel();
JPanel myPanel3 = new JPanel();
public MyFrame()
getContentPane().setLayout(null);
getContentPane().setSize(600, 400);
myPanel.setBounds(0, 0, 200, 200);
myPanel2.setBounds(0, 200, 200, 200);
myPanel3.setBounds(0, 400, 200, 100);
getContentPane().add(myPanel);
getContentPane().add(myPanel2);
getContentPane().add(myPanel3);
// javax.swing.Timer to update myPanel
Timer t = new Timer( 2000, new ActionListener() {
public void actionPerformed(ActionEvent e) {
myPanel.repaint();
t.start();
I actually use othe class names and field names, but the structure is basically the same.
Any idea of what am I doing wrong? Why Panels work fine in the same situation, into the same JFrame?
Thank you.

Answer 1

Try constructing your JPanels as doublebuffered then. (new JPanel(A layoutmanager, true)). The latter parameter is a boolean for creating a doublebuffered JPanel or not. Try with calling myPanel.revalidate() after repainting.