How to detect repainted areas in a Java application (Windows OS)?

Question

I am debugging graphics updates in a Java application, under Windows 8.

Mac users have Quartz Debug that flash updated screen regions in real-time. This allows to determine repaint frequency and false updates - sometimes only a small area requires a repaint, but the full window is repainted. The application even shows areas that receive an update with unchanged content.

Is there a similar Windows debugging tool allowing me to detect repainted areas?

Answer 1

Meanwhile I found JXLayer, a SwingLabs subproject with BSD license. After including jxlayer-3.0.4.jar into my project library, I was able to animate repaints. If you have a JFrame and a JPanel, use:

JFrame frame = ...;
JPanel panel = ...;
if (DEBUG_REPAINT) {
    JXLayer<JPanel> layer = new JXLayer<>(panel);
    DebugRepaintingUI dp = new DebugRepaintingUI(50); // 50ms delay
    layer.setUI(dp);
    frame.setContentPane(layer);
}
else {
    frame.setContentPane(panel);
}                   }

By default the DebugRepaintingUI draws the changed area in XORMode, but I can adapt the source to create a less obtrusive effect.

This approach has the problem that it actually modifies the application. Maybe someone has a better idea.