/* @test

   @bug 6683775 6794764

   @summary Painting artifacts is seen when panel is made setOpaque(false) for a translucent window

   @author Alexander Potochkin

   @run main bug6683775

*/

import com.sun.awt.AWTUtilities;

import sun.awt.SunToolkit;

import javax.swing.*;

import java.awt.*;

import java.awt.image.BufferedImage;

public class bug6683775 {

    public static void main(String[] args) throws Exception {

        GraphicsConfiguration gc = getGC();

        if (!AWTUtilities.isTranslucencySupported(

                AWTUtilities.Translucency.PERPIXEL_TRANSLUCENT)

                || gc == null) {

            return;

        }

        SunToolkit toolkit = (SunToolkit) Toolkit.getDefaultToolkit();

        Robot robot = new Robot();

        final JFrame testFrame = new JFrame(gc);

        SwingUtilities.invokeLater(new Runnable() {

            public void run() {

                JFrame backgroundFrame = new JFrame("Background frame");

                backgroundFrame.setUndecorated(true);

                JPanel panel = new JPanel();

                panel.setBackground(Color.RED);

                backgroundFrame.add(panel);

                backgroundFrame.setSize(200, 200);

                backgroundFrame.setVisible(true);

                testFrame.setUndecorated(true);

                JPanel p = new JPanel();

                p.setOpaque(false);

                testFrame.add(p);

                AWTUtilities.setWindowOpaque(testFrame, false);

                testFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                testFrame.setSize(400, 400);

                testFrame.setLocation(0, 0);

                testFrame.setVisible(true);

            }

        });

        toolkit.realSync();

        //robot.getPixelColor() didn't work right for some reason

        BufferedImage capture = robot.createScreenCapture(new Rectangle(100, 100));

        int redRGB = Color.RED.getRGB();

        if (redRGB != capture.getRGB(10, 10)) {

            throw new RuntimeException("Transparent frame is not transparent!");

        }

    }

    private static GraphicsConfiguration getGC() {

        GraphicsConfiguration transparencyCapableGC =

                GraphicsEnvironment.getLocalGraphicsEnvironment()

                        .getDefaultScreenDevice().getDefaultConfiguration();

        if (!AWTUtilities.isTranslucencyCapable(transparencyCapableGC)) {

            transparencyCapableGC = null;

            GraphicsEnvironment env =

                    GraphicsEnvironment.getLocalGraphicsEnvironment();

            GraphicsDevice[] devices = env.getScreenDevices();

            for (int i = 0; i < devices.length && transparencyCapableGC == null; i++) {

                GraphicsConfiguration[] configs = devices[i].getConfigurations();

                for (int j = 0; j < configs.length && transparencyCapableGC == null; j++) {

                    if (AWTUtilities.isTranslucencyCapable(configs[j])) {

                        transparencyCapableGC = configs[j];

                    }

                }

            }

        }

        return transparencyCapableGC;

    }

}