FULL PRODUCT VERSION :
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode, sharing)
6.0 build 93

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
When two components (lets call them top and bottom components) are stacked one over the other using an OverlayLayout, a repaint (such as one initiated by a mouse over or a mouse click on a button) on the bottom component does not trigger an automatic repaint on the top component. This causes the top component to not paint, or paint partially, until an explicit refresh is performed on it, such as by resizing the Java window that contains the two stacked components.

See example below for how to reproduce this problem.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Copy and paste the source code listed in the Source Code section into Notepad.
2. Save to file to OverlayTest.java
3. Compile the code: javac OverlayTest.java
4. Run the code: java -classpath . OverlayTest
5. A small window will appear consisting of two JPanels stacked one over the other using an OverlayLayout. The bottom panel contains a JButton and a JLabel. The top panel is empty and has its background color set to translucent red, so that the bottom panel is visible through it.
6. Mouseover or click on the button. Notice how the portion of the translucent JPanel that lies over the button does not paint.
9. Next, notice how this effect is not observed when you mouseover or click on the JLabel.
10. Resize the window or minimize and restore it and notice that the portion of the translucent JPanel over the JButton that was not painting before, has now repainted correctly.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -

Expected Result:

Clicking or mousing over the JButton should trigger an automatic repaint of the translucent top panel. Moreover the translucent top panel in an OverlayLayout should repaint _after_ the bottom panel paints.

ACTUAL -

Actual Result:

The portion of the translucent JPanel that lies on top of the JButton (the JButton is part of the bottom component) does not repaint when an event (such as a mouseover or a mouseclick) on the JButton causes the JButton to repaint.
 

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
//----- START OverlayTest .java -----

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.OverlayLayout;
import javax.swing.SwingConstants;

public class OverlayTest {

    public static void test() {
        JFrame f = new JFrame();
        f.getContentPane().setLayout(new BorderLayout());

        JPanel holderPane = new JPanel();
        holderPane.setLayout(new OverlayLayout(holderPane));

        JPanel topPane = new JPanel();
        topPane.setOpaque(true);
        topPane.setBackground(new Color(255, 0, 0, 64));
        holderPane.add(topPane);

        JPanel bottomPane = new JPanel(new GridLayout(2, 1, 2, 2));
        bottomPane.setOpaque(true);
        bottomPane.add(new JLabel("Label", SwingConstants.CENTER));
        bottomPane.add(new JButton("Button"));
        holderPane.add(bottomPane);

        f.getContentPane().add(holderPane);
        
        f.pack();
        f.setVisible(true);
    }

    public static void main(String[] args) {
        test();
    }
}


//----- END OverlayTest .java -----

---------- END SOURCE ----------