Re: Translucent volatile image appears opaque

"Knute Johnson" <nospam@rabbitbrush.frazmtn.com> wrote in message
news:dc%%n.10095$Zp1.6880@newsfe15.iad...


[...]

I have adapted your SSCCE for using a volatile image as below. The
result is that the VI has a background of opaque white and paints over
the blue background of the panel. How can I get it to be translucent? As
you can see I am explicitly creating a translucent image.

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Transparency;
import java.awt.image.VolatileImage;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class VITest extends JPanel {

private VolatileImage vi;

public VITest() {
setPreferredSize(new Dimension(500, 400));
setBackground(Color.BLUE);
}

public static void main(final String[] args) {
EventQueue.invokeLater(new Runnable() {

@Override
public void run() {
final JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final VITest t = new VITest();
f.add(t);
f.pack();
f.setVisible(true);
t.init();
}
});
}

private void createVI() {
vi = getGraphicsConfiguration().createCompatibleVolatileImage(400, 300,
Transparency.TRANSLUCENT);
}

private void init() {
createVI();
renderToVI();
}

@Override
public void paintComponent(final Graphics g) {
super.paintComponent(g);
do {
final int returnCode = vi.validate(getGraphicsConfiguration());
if (returnCode == VolatileImage.IMAGE_RESTORED) {
renderToVI();
} else if (returnCode == VolatileImage.IMAGE_INCOMPATIBLE) {
createVI();
renderToVI();
}
final Graphics2D g2d = (Graphics2D)g;
g2d.drawImage(vi, 0, 0, this);
} while (vi.contentsLost());
}

private void renderToVI() {
do {
if (vi.validate(getGraphicsConfiguration()) ==
VolatileImage.IMAGE_INCOMPATIBLE) {
createVI();
}
final Graphics2D g = vi.createGraphics();
g.setColor(Color.BLACK);
g.drawString("Hello World", 5, 20);
g.dispose();
} while (vi.contentsLost());
}
}