Transparency problems with JPanel

I wrote a color chooser application, where I can change the RGB values and
the alpha value by a JSlider. If a slider is changed the background
color of an additional JPanel is set. If alpha is lesser 1.0 (255), than
a slider is shown in the additional Panel (jPanelColor).
Following my source code, only with the red and alpha slider.
Thanks in advance for helping
Markus
import java.awt.Color;
public class ColorView extends javax.swing.JFrame {
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanelAlpha;
private javax.swing.JPanel jPanelColor;
private javax.swing.JPanel jPanelLabel;
private javax.swing.JPanel jPanelRed;
private javax.swing.JSlider jSliderAlpha;
private javax.swing.JSlider jSliderRed;
private javax.swing.JTextField jTextFieldAlpha;
private javax.swing.JTextField jTextFieldRed;
private int red;
private int alpha;
public ColorView() {
red = 0;
alpha = 0;
initComponents();
updateView();
private void initComponents() {
java.awt.GridBagConstraints gridBagConstraints;
jPanelColor = new javax.swing.JPanel();
jPanelLabel = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jPanelRed = new javax.swing.JPanel();
jSliderRed = new javax.swing.JSlider();
jTextFieldRed = new javax.swing.JTextField();
jPanelAlpha = new javax.swing.JPanel();
jSliderAlpha = new javax.swing.JSlider();
jTextFieldAlpha = new javax.swing.JTextField();
getContentPane().setLayout(new java.awt.GridBagLayout());
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowClosing(java.awt.event.WindowEvent evt) {
exitForm(evt);
jPanelColor.setLayout(new java.awt.GridBagLayout());
jPanelColor.setPreferredSize(new java.awt.Dimension(100, 100));
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 1.0;
getContentPane().add(jPanelColor, gridBagConstraints);
jPanelLabel.setLayout(new java.awt.GridBagLayout());
jLabel1.setFont(new java.awt.Font("MS Sans Serif", 1, 24));
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setText("My Label");
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 1.0;
jPanelLabel.add(jLabel1, gridBagConstraints);
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH;
gridBagConstraints.weightx = 1.0;
gridBagConstraints.weighty = 1.0;
getContentPane().add(jPanelLabel, gridBagConstraints);
jPanelRed.setLayout(new java.awt.GridBagLayout());
jPanelRed.setBorder(new javax.swing.border.TitledBorder("Red"));
jSliderRed.setMaximum(255);
jSliderRed.setValue(red);
jSliderRed.addChangeListener(new javax.swing.event.ChangeListener() {
public void stateChanged(javax.swing.event.ChangeEvent evt) {
redStateChanged(evt);
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
gridBagConstraints.weightx = 1.0;
jPanelRed.add(jSliderRed, gridBagConstraints);
jTextFieldRed.setColumns(3);
jTextFieldRed.setEditable(false);
jTextFieldRed.setHorizontalAlignment(javax.swing.JTextField.RIGHT);
jTextFieldRed.setText(Integer.toString( red));
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 1;
gridBagConstraints.gridy = 0;
gridBagConstraints.insets = new java.awt.Insets(0, 5, 0, 0);
jPanelRed.add(jTextFieldRed, gridBagConstraints);
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 1;
gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
gridBagConstraints.weightx = 1.0;
getContentPane().add(jPanelRed, gridBagConstraints);
jPanelAlpha.setLayout(new java.awt.GridBagLayout());
jPanelAlpha.setBorder(new javax.swing.border.TitledBorder("Alpha"));
jSliderAlpha.setMaximum(255);
jSliderAlpha.setValue(alpha);
jSliderAlpha.addChangeListener(new javax.swing.event.ChangeListener() {
public void stateChanged(javax.swing.event.ChangeEvent evt) {
alphaStateChanged(evt);
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 0;
gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
gridBagConstraints.weightx = 1.0;
jPanelAlpha.add(jSliderAlpha, gridBagConstraints);
jTextFieldAlpha.setColumns(3);
jTextFieldAlpha.setEditable(false);
jTextFieldAlpha.setHorizontalAlignment(javax.swing.JTextField.RIGHT);
jTextFieldAlpha.setText(Integer.toString( alpha));
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 1;
gridBagConstraints.gridy = 0;
gridBagConstraints.insets = new java.awt.Insets(0, 5, 0, 0);
jPanelAlpha.add(jTextFieldAlpha, gridBagConstraints);
gridBagConstraints = new java.awt.GridBagConstraints();
gridBagConstraints.gridx = 0;
gridBagConstraints.gridy = 4;
gridBagConstraints.fill = java.awt.GridBagConstraints.HORIZONTAL;
gridBagConstraints.weightx = 1.0;
getContentPane().add(jPanelAlpha, gridBagConstraints);
pack();
private void alphaStateChanged(javax.swing.event.ChangeEvent evt) {
alpha = jSliderAlpha.getValue();
jTextFieldAlpha.setText( Integer.toString( alpha));
updateView();
private void redStateChanged(javax.swing.event.ChangeEvent evt) {
red = jSliderRed.getValue();
jTextFieldRed.setText( Integer.toString( red));
updateView();
private void updateView() {
jPanelColor.setBackground( new Color( red, 0, 0, alpha));
// repaint();
private void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
* @param args the command line arguments
public static void main(String args[]) {
new ColorView().show();
}

My problem is, the slider must not visible in the additional
panel (called jPanelColor). I do not add the slider into the jPanelColor.
This behavior exists only if the transparancy is lesser than 1.0
An additional info, I use java version 1.4.2_04

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     else if (dayInt == Calendar.WEDNESDAY) {
       label.setText("Mit");
     else if (dayInt == Calendar.THURSDAY) {
       label.setText("Don");
     else if (dayInt == Calendar.FRIDAY) {
       label.setText("Fre");
     else if (dayInt == Calendar.SATURDAY) {
       label.setText("Sam");
     days.add(label);
   Calendar setupCalendar = (Calendar) calendar.clone();
   setupCalendar.set(Calendar.DAY_OF_MONTH, 1);
   int firstday = setupCalendar.get(Calendar.DAY_OF_WEEK);
   for (int i = 1; i < (firstday - 1); i++) {
     days.add(new JLabel(""));
   for (int i = 1; i <=setupCalendar.getActualMaximum(Calendar.DAY_OF_MONTH); i++) {
     int day = setupCalendar.get(Calendar.DAY_OF_MONTH);
     final Date d = setupCalendar.getTime();
     final JLabel label = new JLabel(String.valueOf(day));
     label.setOpaque(true);
     if(this.manger.isTerminAtDay(d)) {
       String s="<html><center>" + day + "<br>";
       if(this.manger.isBirthdayAtDay(d)) {
         s+="Geburtstag<br>";
       if(this.manger.isOtherTerminAtDay(d)) {
         s+="Termin";
       label.setText(s);
       label.addMouseListener(new MouseListener() {
          * mouseClicked
          * @param e MouseEvent
         public void mouseClicked(MouseEvent e) {
           Termin[] t = Kalender.this.manger.getTermineAtDay(d);
           if (t.length == 1) {
             new TerminDialog(null, t[0]);
           else {
             new TerminAuswahlDialog(null, t, d);
          * mouseEntered
          * @param e MouseEvent
         public void mouseEntered(MouseEvent e) {
          * mouseExited
          * @param e MouseEvent
         public void mouseExited(MouseEvent e) {
          * mousePressed
          * @param e MouseEvent
         public void mousePressed(MouseEvent e) {
          * mouseReleased
          * @param e MouseEvent
         public void mouseReleased(MouseEvent e) {
     final Color background=label.getBackground();
     final Color foreground=label.getForeground();
     label.setHorizontalAlignment(JLabel.CENTER);
     label.addMouseListener(new MouseAdapter() {
       public void mouseEntered(MouseEvent e) {
         label.setBackground(Color.BLUE);
         label.setForeground(Color.RED);
       public void mouseExited(MouseEvent e) {
         label.setBackground(background);
         label.setForeground(foreground);
     days.add(label);
     setupCalendar.roll(Calendar.DAY_OF_MONTH,true);
   this.add(days, BorderLayout.CENTER);
   this.revalidate();
private JLabel createUpdateButton(final int field,final int amount) {
   final JLabel label = new JLabel();
   final Border selectedBorder = new EtchedBorder();
   final Border unselectedBorder = new EmptyBorder(selectedBorder
       .getBorderInsets(new JLabel()));
   label.setBorder(unselectedBorder);
   label.addMouseListener(new MouseAdapter() {
     public void mouseReleased(MouseEvent e) {
       calendar.add(field, amount);
       Kalender.this.updatePanel();
     public void mouseEntered(MouseEvent e) {
       label.setBorder(selectedBorder);
     public void mouseExited(MouseEvent e) {
       label.setBorder(unselectedBorder);
   return label;
private void initializeJPanel() {
   JPanel header = new JPanel();
   JLabel label;
   label = this.createUpdateButton(Calendar.YEAR, -1);
   label.setText("<<");
   header.add(label);
   label = this.createUpdateButton(Calendar.MONTH, -1);
   label.setText("<");
   header.add(label);
   monthLabel=new JLabel("");
   header.add(monthLabel);
   label = this.createUpdateButton(Calendar.MONTH, 1);
   label.setText(">");
   header.add(label);
   label = this.createUpdateButton(Calendar.YEAR, 1);
   label.setText(">>");
   header.add(label);
   this.setLayout(new BorderLayout());
   this.add(header, BorderLayout.NORTH);
}

I got you code to compile and run and made a single change to get it to work; adding a call to repaint at the end of the updatePanel method.
        this.add(days, BorderLayout.CENTER);
        this.revalidate();
        repaint();
    }Whenever you change the size of a containers components or add/remove components you must ask the container to run through its component hierarchy and check the size requirements of all its children and lay them out again, ie, do a new layout. The JComponent method for this isrevalidate. If you are working in the AWT you must use the Component/(overridden in)Container method validate, sometimes preceded by a call to the invalidate method. Some people prefer the validate method over revalidate. These are methods used to update guis by asking for a renewed layout. For economy you can call one (sometimes with invalidate, but rarely) of these methods on the smallest component/container that includes all the containers needing the renewed layout, ie, keep the action as localized as possible.
When the rendering of components has changed, things like colors, borders and text, we need to ask the components to repaint themselves. The easy way to do this is to call repaint on the gui. For economy you can call repaint on the smallest component that contains all the components needing repainting. Some classes like those in the JTextComponent group have their own internal repainting calls so they will repaint themselves when changes are made.
In making guis, especially elaborate ones, it seems to take some playful experimentation to find out what is needed to get what you want. Sometimes it is a call to revalidate, sometimes a call to repaint, sometimes both. You just have to experiment.

Problem with jpanel and image

i have a jinternalframe with gridbaglayout which has several jpanels. one of the jpanels has to display an image.
i have searched through the forum and i have made a method to draw the image,
but the problem is that when i added to the jpanel the last (jpanel) gets much bigger and as a result to break down the layout.
any help is appreciated!

i have searched through the forum and i have made a method to draw the image,Just add the image to a JLabel.
when i added to the jpanel the last (jpanel) gets much bigger[url http://java.sun.com/docs/books/tutorial/uiswing/layout/visual.html]How to Use Layout Managers

Menu transparency Problem with Safari

Hi,
I'm having an issue with Safari and would be greateful if anyone could help.
My menu items appear about 50% transparent and I don't know why. My only guess is that it is a Z-Index issue with the background image beneath it? All help welcome and appreciated.
If you take a look at the below link in Safari, you will see what I mean:
http://www.s217794495.websitehome.co.uk/ProActive1st_PROOF/
Many thanks in advance.

HI and welcome...
Remove that particular desktop wallpaper. That's probably what's causing your to lose History and TopSites.
Open a Finder window. Now open the Library folder then the Safari folder. See if that wallpaper is hiding in the Safari folder. Mine does that also. If it's there, move it to the Trash but don't empty the Trash.
Quit Safari (Command + Q) Now relaunch Safari. If History and TopSites are ok, then empty the Trash. It's that image causing the problem.
Carolyn

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