title: Java AWT Draw on Translucent Frame
body: <p>I am having trouble drawing on a translucent frame.  When the "alphaValue" is 255 everything works as expected.  But I need a translucent frame.  I created a small test class below that demonstrates the problem.  As you can see the "MIDDLE" rectangle appears all the time.  But the "DRAW" rectangle only appears when "alphaValue" is 255.  When it is &lt;=254 you can see via print lines that the method is still called, but the image does not appear to refresh.  Thank you in advance for any help.</p>
  
  <pre><code>import java.awt.Color;
  import java.awt.Frame;
  import java.awt.Graphics;
  import java.awt.Panel;
  import java.awt.Point;
  import java.awt.event.MouseAdapter;
  import java.awt.event.MouseEvent;
  
  public class TransparencyTest {
      private static Point startPoint = new Point();
      private static Point endPoint = new Point();
  
      public static void main(String[] args) {
          new TransparencyTest().test();
      }
  
      @SuppressWarnings("serial")
      private void test() {
          int alphaValue = 255;
  
          Frame myFrame = new Frame();
          myFrame.setUndecorated(true);
          myFrame.setBackground(new Color(0, 0, 0, alphaValue));
          myFrame.setSize(800, 800);
  
          Panel myPanel = new Panel() {
              public void paint(Graphics g) {
                  super.paint(g);
                  System.out.println("PAINT");
                  g.setColor(new Color(255, 0, 0, 255));
                  if(startPoint.equals(new Point())) {
                      System.out.println("MIDDLE");
                      g.drawRect(200, 200, 400, 400);
                  }
                  else {
                      System.out.println("DRAW");
                      g.drawRect(
                              (int)Math.min(startPoint.getX(), endPoint.getX()),
                              (int)Math.min(startPoint.getY(), endPoint.getY()),
                              (int)Math.abs(startPoint.getX() - endPoint.getX()),
                              (int)Math.abs(startPoint.getY() - endPoint.getY())
                      );
                  }
              }
          };
          myFrame.add(myPanel);
  
          MouseAdapter myMouseAdapter = new MouseAdapter() {
              public void mousePressed(MouseEvent e) {
                  startPoint = e.getPoint();
              }
  
              public void mouseDragged(MouseEvent e) {
                  endPoint = e.getPoint();
                  myPanel.repaint();
              }
          };
          myPanel.addMouseListener(myMouseAdapter);
          myPanel.addMouseMotionListener(myMouseAdapter);
  
          myFrame.setVisible(true);
      }
  }
  </code></pre>