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  1. JDK
  2. JDK-8050265

Per-Pixel Translucency Compositing is Broken on Ubuntu

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    • OS:
      windows_7

      Description

      FULL PRODUCT VERSION :
      java version " 1.7.0_13 "
      Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
      Java HotSpot(TM) Client VM (build 23.7-b01, mixed mode)


      ADDITIONAL OS VERSION INFORMATION :
      Ubuntu 12.04.1 LTS

      A DESCRIPTION OF THE PROBLEM :
      Using the " GradientTranslucentWindowDemo " example from http://docs.oracle.com/javase/tutorial/uiswing/misc/trans_shaped_windows.html you can see the result of window translucency working. However, if you gradually decrease any of the color components (R, G, or B), the color compositing is incorrect.

      isWindowTranslucencySupported(PERPIXEL_TRANSLUCENT) report true.

      Testing Windows 7, Vista and Mac OS X Mountain Lion; all work as expected.

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      Get the " GradientTranslucentWindowDemo " example from http://docs.oracle.com/javase/tutorial/uiswing/misc/trans_shaped_windows.html.

      Change any of the color components of the gradient (final int R,G, or B) to something lower, i recommend 0 to see the full effect.

      Run the app.

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      You should see the color defined by R, G, and B with a gradient alpha value, starting at full transparent, and ending fully opaque.

      On windows 7:
      http://imageshack.us/photo/my-images/834/windows7s.png/
      ACTUAL -
      The background of the frame is the gradient color specified but is mixed with the desktop/background windows incorrectly.

      On Ubuntu:
      http://imageshack.us/photo/my-images/805/ubuntuw.png/

      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      import static java.awt.GraphicsDevice.WindowTranslucency.PERPIXEL_TRANSLUCENT;

      import java.awt.Color;
      import java.awt.Dimension;
      import java.awt.GradientPaint;
      import java.awt.Graphics;
      import java.awt.Graphics2D;
      import java.awt.GraphicsDevice;
      import java.awt.GraphicsEnvironment;
      import java.awt.GridBagLayout;
      import java.awt.Paint;

      import javax.swing.JButton;
      import javax.swing.JFrame;
      import javax.swing.JPanel;
      import javax.swing.SwingUtilities;
      import javax.swing.UIManager;
      import javax.swing.UIManager.LookAndFeelInfo;

      public class GradientTranslucentWindowDemo extends JFrame {
          public GradientTranslucentWindowDemo() {
              super( " GradientTranslucentWindow " );

              setUndecorated(true);
              setBackground(new Color(0,0,0,0));
              setSize(new Dimension(300,200));
              setLocationRelativeTo(null);
              setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

              JPanel panel = new JPanel() {
                  @Override
                  protected void paintComponent(Graphics g) {
                      if (g instanceof Graphics2D) {
                          final int R = 0; // HERE IS THE ONLY CHANGE
                          final int G = 240;
                          final int B = 240;

                          Paint p =
                              new GradientPaint(0.0f, 0.0f, new Color(R, G, B, 0),
                                  0.0f, getHeight(), new Color(R, G, B, 255), true);
                          Graphics2D g2d = (Graphics2D)g;
                          g2d.setPaint(p);
                          g2d.fillRect(0, 0, getWidth(), getHeight());
                      }
                  }
              };
              setContentPane(panel);
              setLayout(new GridBagLayout());
              add(new JButton( " I am a Button " ));
              
              setAlwaysOnTop(true);
          }

          public static void main(String[] args) {
              // Determine what the GraphicsDevice can support.
              GraphicsEnvironment ge =
                  GraphicsEnvironment.getLocalGraphicsEnvironment();
              GraphicsDevice gd = ge.getDefaultScreenDevice();
              boolean isPerPixelTranslucencySupported =
                  gd.isWindowTranslucencySupported(PERPIXEL_TRANSLUCENT);

              //If translucent windows aren't supported, exit.
              if (!isPerPixelTranslucencySupported) {
                  System.out.println(
                       " Per-pixel translucency is not supported " );
                      System.exit(0);
              }

              try {
                  for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                      if ( " Nimbus " .equals(info.getName())) {
                          UIManager.setLookAndFeel(info.getClassName());
                          break;
                      }
                  }
              } catch (Exception e) {
                  // If Nimbus is not available, you can set the GUI to another look and feel.
              }
              
              //JFrame.setDefaultLookAndFeelDecorated(true);

              // Create the GUI on the event-dispatching thread
              SwingUtilities.invokeLater(new Runnable() {
                  @Override
                  public void run() {
                      GradientTranslucentWindowDemo gtw = new GradientTranslucentWindowDemo();

                      // Display the window.
                      gtw.setVisible(true);
                  }
              });
          }
      }

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

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              Assignee:
              scfitch Stephen Fitch
              Reporter:
              webbuggrp Webbug Group
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                Created:
                Updated:
                Resolved: