Why update(Graphics g) in JPanel is not called?

Question

Hi,
I have Overridden the following two functions in a JPanel:
1. void paint(Graphics g)
2. void update(Graphics g)
in order to define my own content in the JPanel. As far as I know that override update() by the following code:
public void update(Graphics g)
System.out.println("update is called");
     paint(g);
the original content will not be cleared when it is repainted.
However, I find that update() has never been called. And the content is cleared to its default background color before my defined content is painted. it leads to flashing of the screen.
can anyone tell me why update() is not called??
Thank you,
FS

Answer 1

Hi,
YOu should read the following article that explains the differences between AWT and Swing painting.
http://java.sun.com/products/jfc/tsc/articles/painting/index.html
The article makes one important distinction between the two:
This means that for Swing components, update() is never invoked.
Regards,
Manfred.