Java Transparency rendering error

Question

I am currently developing a kiosk style Java program to display weather, time, forecast etc. Here is a shot of what the program should look like (screenshot taken before the time updated)

Image showing required output before the graphical error

The various sections are created as JPanels with the paintComponent() method overridden. They draw in a gradient header and a semitransparent background. However, when I change the content of one of these panels, the previous content is left behind, rather than being removed. An example is shown below:

As you can see, when the time changed from 11:51 to 11:52, the numbers overlapped, and the background became lighter (because the semitransparent background was redrawn over it)

The Graphical Error

Image showing the graphical error

What should I do to prevent this overlap? Ultimately, I would prefer to not have to redraw the entire screen when an individual panel updates it's contents. I would prefer to only redraw that particular section. It would be easy to repaint the background, and then all the components within.

Update

Several answers involve clearing the area to be drawn. Whether I use g.clear() or AlphaComposite.CLEAR it erases the background image. this can be seen in the following image. Perhaps if I could copy the background before I clear the area, I could repaint that section of the background, then layer the other images appropriately. Thoughts?

enter image description here

Update 2

An answer was submitted which shows a complete working example of a timer laid over a transparent panel and a background. This is very useful, however, I am not painting my sub-componenets manually. The time, weather icons and temperatures are all JLabels laid out over the semi-transparent panel. I would prefer to not have to paint the individual components manually.

Ah, I am overriding `paintComponent()` but mistyped. I will edit the question to reflect this — Peaches491, Jul 27 '12 at 18:39
Are the components set to transparent? `setOpaque(false)` it's hard to tell with out a code sample — MadProgrammer, Jul 27 '12 at 23:08

score 4 · Answer 1 · edited Aug 22 '19 at 17:11

4

A similar problem

is addressed here

Note also, "Swing programs should override paintComponent() instead of overriding paint()."—Painting in AWT and Swing: The Paint Methods.

edited Aug 22 '19 at 17:11

Glorfindel

19,729
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answered Jul 27 '12 at 17:27

trashgod

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Why "here" contains the link to the image shown below ? Or is it suppose to contain the link to your answer ? – nIcE cOw Jul 27 '12 at 17:45
You're MOST WELCOME and KEEP SMILING :-) – nIcE cOw Jul 27 '12 at 17:54
That is very helpful, but the problem persists if I try to clear an area. It then erases the picture which is showing through, and the text is then drawn on the background of the root pane. – Peaches491 Jul 27 '12 at 19:33
If you can't use Java 7 or your platform precludes a transparent top-level container, you might try a [full screen window](http://stackoverflow.com/a/7457102/230513) and render the background on a panel added to the root pane. – trashgod Jul 27 '12 at 20:37

score 3 · Answer 2 · answered Jul 27 '12 at 16:03

3

Before you do your paint, make a g.clearRect(0,0,w,h) call. This will remove everything in the specified area, and you won't be drawing on top of the previous frame.

You may want to apply some double buffering techniques since your screen will flash slightly due to the clear.

answered Jul 27 '12 at 16:03

xthexder

1,512
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I've tried that, but it fills in the background with the default grey background. How could it to truely clear the pixels? Also, wouldnt that erase the background as well? – Peaches491 Jul 27 '12 at 16:05
The documentation says it `Clears the specified rectangle by filling it with the background color of the current drawing surface.` It doesn't actually clear the graphics context. – Zong Jul 27 '12 at 16:06
You will need to set the background color of your panel, since that's what it sets the colors to. panel.setBackground(new Color(0, 0, 0, 0)); – xthexder Jul 27 '12 at 16:07
clearRect may "fill" the background, but it doesn't it differently from fillRect. It replaces the existing value of each pixel rather than adding to it. – xthexder Jul 27 '12 at 16:09
Found this question too, which may be useful to you: http://stackoverflow.com/questions/2367365/clear-a-transparent-bufferedimage-as-fast-as-possible – xthexder Jul 27 '12 at 16:11
Thank you for your help. I've tried several methods to remove the already painted image, but it also removes the background image which is meant to show through. I've updated the question to reflect this – Peaches491 Jul 27 '12 at 19:43
If you are doing the whole window as one image, you will have to repaint it all, including the background. If you use several buffer images, or layered components, then you can redraw easily. If you use buffered images, keep the background as one static image, and then when you redraw, draw that buffer (which is a fast operation) and then the window contents. – xthexder Jul 27 '12 at 20:13

MadProgrammer · Answer 3 · 2012-07-30T20:38:53.023

I put this together really quickly it's nothing special...

enter image description here

The entire project consists of a JFrame, a BackgroundImagePane and the ClockPane

The ClockPane looks like this (as you can recreate the rest ;))

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.RoundRectangle2D;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.Timer;

public class ClockPane extends javax.swing.JPanel {

    private Timer tick;

    protected static final SimpleDateFormat SDF = new SimpleDateFormat("HH:mm.ss");

    public ClockPane() {

        setOpaque(false);

        tick = new Timer(500, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent ae) {

                repaint();

            }

        });

        tick.setCoalesce(true);
        tick.setRepeats(true);

        setPreferredSize(new Dimension(100, 100));
        setMinimumSize(new Dimension(100, 100));

    }

    @Override
    public void addNotify() {

        super.addNotify();

        tick.start();

    }

    @Override
    public void removeNotify() {

        tick.stop();

        super.removeNotify();

    }

    @Override
    protected void paintComponent(Graphics grphcs) {

        super.paintComponent(grphcs);

        Graphics2D g2d = (Graphics2D) grphcs;

        int width = getWidth() - 1;
        int height = getHeight() - 1;

        Color background = new Color(192, 192, 192, 128);
        Color border = new Color(128, 128, 128);
        RoundRectangle2D backing = new RoundRectangle2D.Float(0, 0, width, height, 20, 20);

        g2d.setPaint(background);
        g2d.fill(backing);
        g2d.setPaint(border);
        g2d.draw(backing);

        String text = SDF.format(new Date());
        FontMetrics fm = g2d.getFontMetrics();
        g2d.setPaint(Color.BLACK);

        int x = (width - fm.stringWidth(text)) / 2;
        int y = ((height - fm.getHeight()) / 2) + fm.getAscent();

        g2d.drawString(text, x, y);

    }

}

With this, the clock updates every half second or so and I have no issues with the repaint

The only thing of significance I can think of is setOpaque(false);

UPDATED

This example is completly done with nothing but labels and panels (the background pane is a custom paint job and the date label has its background painted as well, but otherwise)

Normal Components

Now, I hacked my together, so it's not as nice as yours, but then again, I'm not getting paid ;)

import core.ui.UIUtilities;
import core.ui.WindowUtilities;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.Timer;
import javax.swing.UIManager;

public class MainFrame extends javax.swing.JFrame {

    /**
     * Creates new form MainFrame
     */
    public MainFrame() {

        setUndecorated(true);
        WindowUtilities.setOpaque(this, false);

        initComponents();

        Timer timer = new Timer(500, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                lblTime.setText(new SimpleDateFormat("hh:MM:ss").format(new Date()));

            }
        });

        timer.setRepeats(true);
        timer.setCoalesce(true);
        timer.start();

        DateLabel label = new DateLabel();
        label.init();

        NewBackgroundPane backgroundPane = new NewBackgroundPane();
        backgroundPane.setLayout(new BorderLayout());
        backgroundPane.add(label, BorderLayout.NORTH);
        backgroundPane.add(pnlMain);

        add(backgroundPane, BorderLayout.CENTER);

        pack();

        setLocation(UIUtilities.centerOfDefaultScreen(this));

    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {
        java.awt.GridBagConstraints gridBagConstraints;

        pnlMain = new javax.swing.JPanel();
        jPanel2 = new javax.swing.JPanel();
        lblTime = new javax.swing.JLabel();
        lblExtTime = new javax.swing.JLabel();
        jPanel3 = new javax.swing.JPanel();
        jLabel3 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jLabel5 = new javax.swing.JLabel();
        jLabel6 = new javax.swing.JLabel();
        jPanel4 = new javax.swing.JPanel();
        jPanel5 = new javax.swing.JPanel();
        jLabel11 = new javax.swing.JLabel();
        jLabel12 = new javax.swing.JLabel();
        jLabel13 = new javax.swing.JLabel();
        jLabel14 = new javax.swing.JLabel();
        jPanel6 = new javax.swing.JPanel();
        jLabel15 = new javax.swing.JLabel();
        jLabel16 = new javax.swing.JLabel();
        jLabel17 = new javax.swing.JLabel();
        jLabel18 = new javax.swing.JLabel();
        jPanel7 = new javax.swing.JPanel();
        jLabel19 = new javax.swing.JLabel();
        jLabel20 = new javax.swing.JLabel();
        jLabel21 = new javax.swing.JLabel();
        jLabel22 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        pnlMain.setOpaque(false);
        pnlMain.setLayout(new java.awt.GridBagLayout());

        jPanel2.setOpaque(false);
        jPanel2.setLayout(new java.awt.GridBagLayout());

        lblTime.setFont(lblTime.getFont().deriveFont(lblTime.getFont().getStyle() | java.awt.Font.BOLD, lblTime.getFont().getSize()+18));
        lblTime.setForeground(new java.awt.Color(255, 255, 255));
        lblTime.setText("jLabel1");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        jPanel2.add(lblTime, gridBagConstraints);

        lblExtTime.setFont(lblExtTime.getFont().deriveFont(lblExtTime.getFont().getSize()+6f));
        lblExtTime.setForeground(new java.awt.Color(255, 255, 255));
        lblExtTime.setText("AM EDT");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel2.add(lblExtTime, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.insets = new java.awt.Insets(2, 2, 2, 2);
        pnlMain.add(jPanel2, gridBagConstraints);

        jPanel3.setOpaque(false);
        jPanel3.setLayout(new java.awt.GridBagLayout());

        jLabel3.setIcon(new javax.swing.ImageIcon(getClass().getResource("/transparentUpdate/Overcast.png"))); // NOI18N
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridheight = 2;
        jPanel3.add(jLabel3, gridBagConstraints);

        jLabel4.setFont(jLabel4.getFont().deriveFont(jLabel4.getFont().getSize()+6f));
        jLabel4.setForeground(new java.awt.Color(255, 255, 255));
        jLabel4.setText("<html>Currenctly<br>Overast</html>");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.FIRST_LINE_START;
        jPanel3.add(jLabel4, gridBagConstraints);

        jLabel5.setFont(jLabel5.getFont().deriveFont(jLabel5.getFont().getSize()+12f));
        jLabel5.setForeground(new java.awt.Color(255, 255, 255));
        jLabel5.setText("69");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.LAST_LINE_START;
        jPanel3.add(jLabel5, gridBagConstraints);

        jLabel6.setForeground(new java.awt.Color(255, 255, 255));
        jLabel6.setText("/65");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 2;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.LAST_LINE_START;
        jPanel3.add(jLabel6, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.insets = new java.awt.Insets(2, 2, 2, 2);
        pnlMain.add(jPanel3, gridBagConstraints);

        jPanel4.setOpaque(false);
        jPanel4.setLayout(new java.awt.GridBagLayout());

        jPanel5.setOpaque(false);
        jPanel5.setLayout(new java.awt.GridBagLayout());

        jLabel11.setFont(jLabel11.getFont().deriveFont(jLabel11.getFont().getSize()+4f));
        jLabel11.setForeground(new java.awt.Color(255, 255, 255));
        jLabel11.setText("Today");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 2;
        jPanel5.add(jLabel11, gridBagConstraints);

        jLabel12.setForeground(new java.awt.Color(255, 255, 255));
        jLabel12.setIcon(new javax.swing.ImageIcon(getClass().getResource("/transparentUpdate/SmallOvercast.png"))); // NOI18N
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.gridheight = 2;
        jPanel5.add(jLabel12, gridBagConstraints);

        jLabel13.setFont(jLabel13.getFont().deriveFont(jLabel13.getFont().getSize()+4f));
        jLabel13.setForeground(new java.awt.Color(255, 255, 255));
        jLabel13.setText("83");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel5.add(jLabel13, gridBagConstraints);

        jLabel14.setForeground(new java.awt.Color(255, 255, 255));
        jLabel14.setText("65");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel5.add(jLabel14, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        gridBagConstraints.insets = new java.awt.Insets(2, 4, 2, 4);
        jPanel4.add(jPanel5, gridBagConstraints);

        jPanel6.setOpaque(false);
        jPanel6.setLayout(new java.awt.GridBagLayout());

        jLabel15.setFont(jLabel15.getFont().deriveFont(jLabel15.getFont().getSize()+4f));
        jLabel15.setForeground(new java.awt.Color(255, 255, 255));
        jLabel15.setText("Sunday");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 2;
        jPanel6.add(jLabel15, gridBagConstraints);

        jLabel16.setForeground(new java.awt.Color(255, 255, 255));
        jLabel16.setIcon(new javax.swing.ImageIcon(getClass().getResource("/transparentUpdate/Sunny.png"))); // NOI18N
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.gridheight = 2;
        jPanel6.add(jLabel16, gridBagConstraints);

        jLabel17.setFont(jLabel17.getFont().deriveFont(jLabel17.getFont().getSize()+4f));
        jLabel17.setForeground(new java.awt.Color(255, 255, 255));
        jLabel17.setText("82");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel6.add(jLabel17, gridBagConstraints);

        jLabel18.setForeground(new java.awt.Color(255, 255, 255));
        jLabel18.setText("64");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel6.add(jLabel18, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        gridBagConstraints.insets = new java.awt.Insets(2, 4, 2, 4);
        jPanel4.add(jPanel6, gridBagConstraints);

        jPanel7.setOpaque(false);
        jPanel7.setLayout(new java.awt.GridBagLayout());

        jLabel19.setFont(jLabel19.getFont().deriveFont(jLabel19.getFont().getSize()+4f));
        jLabel19.setForeground(new java.awt.Color(255, 255, 255));
        jLabel19.setText("Monday");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridwidth = 2;
        jPanel7.add(jLabel19, gridBagConstraints);

        jLabel20.setForeground(new java.awt.Color(255, 255, 255));
        jLabel20.setIcon(new javax.swing.ImageIcon(getClass().getResource("/transparentUpdate/Cloudy.png"))); // NOI18N
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.gridheight = 2;
        jPanel7.add(jLabel20, gridBagConstraints);

        jLabel21.setFont(jLabel21.getFont().deriveFont(jLabel21.getFont().getSize()+4f));
        jLabel21.setForeground(new java.awt.Color(255, 255, 255));
        jLabel21.setText("83");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel7.add(jLabel21, gridBagConstraints);

        jLabel22.setForeground(new java.awt.Color(255, 255, 255));
        jLabel22.setText("84");
        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 2;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        jPanel7.add(jLabel22, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 2;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.anchor = java.awt.GridBagConstraints.PAGE_START;
        gridBagConstraints.insets = new java.awt.Insets(2, 4, 2, 4);
        jPanel4.add(jPanel7, gridBagConstraints);

        gridBagConstraints = new java.awt.GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 3;
        gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
        gridBagConstraints.weightx = 1.0;
        gridBagConstraints.insets = new java.awt.Insets(2, 2, 2, 2);
        pnlMain.add(jPanel4, gridBagConstraints);

        getContentPane().add(pnlMain, java.awt.BorderLayout.CENTER);

        pack();
    }// </editor-fold>

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /*
         * Set the Nimbus look and feel
         */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /*
         * If Nimbus (introduced in Java SE 6) is not available, stay with the
         * default look and feel. For details see
         * http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
         */
        try {

            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /*
         * Create and display the form
         */
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new MainFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JLabel jLabel11;
    private javax.swing.JLabel jLabel12;
    private javax.swing.JLabel jLabel13;
    private javax.swing.JLabel jLabel14;
    private javax.swing.JLabel jLabel15;
    private javax.swing.JLabel jLabel16;
    private javax.swing.JLabel jLabel17;
    private javax.swing.JLabel jLabel18;
    private javax.swing.JLabel jLabel19;
    private javax.swing.JLabel jLabel20;
    private javax.swing.JLabel jLabel21;
    private javax.swing.JLabel jLabel22;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JPanel jPanel4;
    private javax.swing.JPanel jPanel5;
    private javax.swing.JPanel jPanel6;
    private javax.swing.JPanel jPanel7;
    private javax.swing.JLabel lblExtTime;
    private javax.swing.JLabel lblTime;
    private javax.swing.JPanel pnlMain;
    // End of variables declaration
}

Just to make life eaiser, the background pane

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;

public class NewBackgroundPane extends javax.swing.JPanel {

    /**
     * Creates new form NewBackgroundPane
     */
    public NewBackgroundPane() {
        initComponents();
    }

    @Override
    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        Graphics2D g2d = (Graphics2D) g.create();

        int width = getWidth() - 1;
        int height = getHeight() - 1;

        g2d.setColor(Color.LIGHT_GRAY);
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
        g2d.fillRoundRect(0, 0, width, height, 20, 20);
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        setOpaque(false);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );
    }// </editor-fold>
    // Variables declaration - do not modify
    // End of variables declaration
}

If you still can't get it to work, the only other issue I can think of could have to something to do with been in full screen, exclusive mode, I've not tested that :P

Thank you for this great example! The only problem is that I am not rendering the time myself. I have several JLabel components laid out carefully around the panel. It's when I update these that I get the issue — Peaches491, Jul 30 '12 at 13:00
You shouldn't have to, the example is soly used to demonstrate that it's possible. I'll see if I can update with labels for :) — MadProgrammer, Jul 30 '12 at 19:23

Java Transparency rendering error

The Graphical Error

Update

Update 2

3 Answers3

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