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How to update look and feel clean seperate in a class?

I want to update my look and feel by JRadioButtonMenuItem. And I searching in Stackoverflow but what I find was a big bunch of code in 1 class. For me as a beginner its easier to seperate function in a special class.
That is my Frame-Class.
public class CalenderFrame extends JFrame {
public CalenderFrame() throws HeadlessException {
createFrame();
}
public void createFrame() {
setJMenuBar(CalenderMenuBar.getInstance().createMenu());
setTitle("Calender");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setPreferredSize(new Dimension(400, 300));
pack();
setLocationRelativeTo(null);
setVisible(true);
}
}
And that is my MenueBar Class. I just give a short one of Code that is specific for this question. This class is an Singleton.
public JMenuBar createMenu() {
JMenu lookAndFeelMenu = new JMenu("Look & Feel");
JRadioButtonMenuItem lAndFWindowsItem = new JRadioButtonMenuItem("Windows",true);
lAndFWindowsItem.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == lAndFWindowsItem) {
lAndFAction(1);
}
}
});
JRadioButtonMenuItem lAndFMetalItem = new JRadioButtonMenuItem("Metal",false);
lAndFMetalItem.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == lAndFMetalItem) {
lAndFAction(2);
}
}
});
JRadioButtonMenuItem lAndFMotifItem = new JRadioButtonMenuItem("Motif", false);
lAndFMotifItem.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == lAndFMotifItem) {
lAndFAction(3);
}
}
});
ButtonGroup group = new ButtonGroup();
group.add(lAndFWindowsItem);
group.add(lAndFMetalItem);
group.add(lAndFMotifItem);
lookAndFeelMenu.add(lAndFWindowsItem);
lookAndFeelMenu.add(lAndFMetalItem);
lookAndFeelMenu.add(lAndFMotifItem);
}
public void lAndFAction(int counter) {
try {
String plaf = "";
if (counter == 1) {
plaf = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
} else if (counter == 2) {
plaf = "javax.swing.plaf.metal.MetalLookAndFeel";
} else if (counter == 3) {
plaf = "com.sun.java.swing.plaf.motif.MotifLookAndFeel";
}
UIManager.setLookAndFeel(plaf);
//SwingUtilities.updateComponentTreeUI(this);
} catch (UnsupportedLookAndFeelException ue) {
System.err.println(ue.toString());
} catch (ClassNotFoundException ce) {
System.err.println(ce.toString());
} catch (InstantiationException ie) {
System.err.println(ie.toString());
} catch (IllegalAccessException iae) {
System.err.println(iae.toString());
}
}
}
I hope you guys can help me.

I'm not sure what your problem actually is. But, you must update your components after changing the LaF. According to the Look and Feel Documentation:
Changing the Look and Feel After Startup
You can change the L&F with setLookAndFeel even after the program's
GUI is visible. To make existing components reflect the new L&F,
invoke the SwingUtilities updateComponentTreeUI method once per
top-level container. Then you might wish to resize each top-level
container to reflect the new sizes of its contained components. For
example:
UIManager.setLookAndFeel(lnfName);
SwingUtilities.updateComponentTreeUI(frame);
frame.pack();
Therefore, you would need a reference to the frame holding the components in your UI. An idea would be doing something like:
public class CalendarMenuBar {
// Add this field to tour factory
private static JFrame frameThatWillBeUpdated;
// ... (Your code goes here)
// update this method to receive the reference of the frame which will
// need to be refreshed (update the GUI)
public JMenuBar createMenu(JFrame frame) {
// sets the reference for the frame
frameThatWillBeUpdated = frame;
// ... (the rest of your code for this method)
}
// ...
// Update this method to refresh the frame
public void lAndFAction(int counter) {
try{
// ... (your code)
// Set the LaF
UIManager.setLookAndFeel(plaf);
// Update the component tree (frame and its children)
SwingUtilities.updateComponentTreeUI(frameThatWillBeUpdated);
// repack to resize
frame.pack();
} catch(Exception ex){
// Your catches
}
}
}
And here is how you use it when creating your frame (inside your CalenderFrame class):
public void createFrame() {
// use this frame as reference
setJMenuBar(CalenderMenuBar.getInstance().createMenu(this));
// ... (your code goes here)
}

JApplet not running properly in eclipse

I wrote a pretty basic applet program in eclipse:
public class SwingAppletDemo extends JApplet {
private static final long serialVersionUID = -1935096480915162747L;
JLabel jl;
public void init() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
new SwingAppletDemo().makeGUI();
}
});
}
catch (Exception e) {
e.printStackTrace();
}
}
private void makeGUI() {
jl = new JLabel("Press a button!");
setLayout(new FlowLayout());
add(jl);
}
}
It compiled fine and then I ran it as an applet by right-clicking on the SwingAppletDemo.java and then I selected Run As > Java Applet
The applet viewer opened but no label was displayed in it. Can anyone please tell me where did I went wrong, I referred to a few tutorials but couldn't find the necessary info.
I also tried running it in Google Chrome but there too only an empty applet was displayed.
Thanx in advance!

You are creating a new SwingAppletDemo in your init method which is never shown. You can simply replace:
new SwingAppletDemo().makeGUI();
with
makeGUI();

Java Applet Game Design : Keyboard focus

I had posted this in a wrong place (GameDev) and got no response there. So I'm posting it again here.
I'm making an applet game and it is rendering, the game loop is running, the animations are updating, but the keyboard input is not working. Here's an SSCCE.
public class Game extends JApplet implements Runnable {
public void init(){
// Initialize the game when called by browser
setFocusable(true);
requestFocus();
requestFocusInWindow(); // Always returning false
GInput.install(this); // Install the input manager for this class
new Thread(this).start();
}
public void run(){
startGameLoop();
}
}
And Here's the GInput class.
public class GInput implements KeyListener {
public static void install(Component c){
new GInput(c);
}
public GInput(Component c){
c.addKeyListener(this);
}
public void keyPressed(KeyEvent e){
System.out.println("A key has been pressed");
}
......
}
This is my GInput class. When run as an applet, it doesn't work and when I add the Game class to a frame, it works properly.
Thanks
Solved now. See my solution

One possible solution is to use the JApplet's contentPane, to set the focus on it rather than on the JApplet itself. But my preference is to use Key Bindings instead. You may need to use a Swing Timer for this to work:
My SSCCE:
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.InvocationTargetException;
import javax.swing.*;
#SuppressWarnings("serial")
public class AppletKeyListen extends JApplet {
#Override
public void init() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
setFocusable(true);
int timerDelay = 100;
Timer myTimer = new Timer(timerDelay , new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
boolean focusObtained = requestFocusInWindow();
System.out.println("focusObtained for JApplet: " + focusObtained);
Container contentPane = getContentPane();
contentPane.setFocusable(true);
focusObtained = contentPane.requestFocusInWindow();
System.out.println("focusObtained for contentPane: " + focusObtained);
}
});
myTimer.setRepeats(false);
myTimer.start();
// boolean focusObtained = requestFocusInWindow();
// System.out.println("focusObtained: " + focusObtained);
//
// Container contentPane = getContentPane();
// contentPane.setFocusable(true);
//
// focusObtained = contentPane.requestFocusInWindow();
// System.out.println("focusObtained: " + focusObtained);
}
});
} catch (InvocationTargetException | InterruptedException e) {
e.printStackTrace();
}
}
}

If you're running in a browser, you probably need to click on the applet to give it focus. For security reasons most browsers won't let an applet just grab the keyboard focus without the user clicking it.
So, I would add a mouse listener instead of doing the focus grabbing directly in init():
addMouseListener(new MouseAdapter() {
public void onMousePress(MouseEvent e) {
requestFocus();
}
});

Now that I have two options,
Use JWS
Don't make an applet mode
Now I had tried to make a new class called GApplet. It loads a game into a new JFrame which worked from the applet. Now I can access the fullscreen mode from web too. Here's a link to the class.
The GApplet class
And now it's working like the webstart and is actually an applet.

Making a mouse button trigger a class event

I am really struggling with making a program that has buttons on it and when a button is clicked, it calls a class to work. I have only been using Java for about 10 weeks now and I get the basics but I have not found any place that gives me an understanding of what I want to do here.
I have tried
public void mouseEntered(MouseEvent e) {
if (e.getButton()== MouseEvent.BUTTON3){
Object triangle;
Frame.class.getClass();
}
}
I have also tried
panel.addMouseListener(new MouseAdapter() {
if (e.getButton()== MouseEvent.BUTTON1) {
Frame.class.getClass(circle); }
Either way I have tried it I usually get an error unable to find object or The method getClass() in the type Objectis not applicable for the arguments (JButton).
Can anyone please help me try to figure out what I am doing wrong?
Thank you.

public class MainFrame extends JFrame {
private JButton button = new JButton("Run AnotherClass");
MainFrame() {
super();
this.setTitle("Demo App");
this.setSize(200,200);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLayout(new FlowLayout());
this.add(button);
button.addActionListener(new ButtonHandler());
}
public class ButtonHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
new AnotherClass();
}
}
public static void main(String[] args) {
new MainFrame().setVisible(true);
}
}
public class AnotherClass {
public AnotherClass() {
JOptionPane.showMessageDialog(null, "AnotherClass is in operation");
}
}

How to quit or exit slave JWindow that was created from a master JWindow in Java?

How can i exit only they new MainGame that i created from Main?
Where Main is having an original layer of game. And the MainGame was a dialog window (such as modal windows).
Main.java: (main code)
public class Main extends JWindow
{
private static JWindow j;
public static MainGame mp;
public static void main(String[] args)
{
new Thread(new Runnable()
{
public void run()
{
mp = new MainGame();
mp.runit();
//mp.stopit();
}
}).start();
j = new Main();
j.setVisible(true);
}
}
MainGame.java: (this was extended by Main, and i would like to quite this only).
public class MainGame extends JWindow
{
private static JWindow j;
public MainGame()
{
// some GUI ...
}
public static void runit()
{
j = new MainGame();
j.setVisible();
}
}

1) better would be implements CardLayout, as create Top-Level Container for new Window, then you'll only to switch betweens Cards
2) don't create lots of Top-Level Container on Runtime, because there are still in JVM memory untill current instance exist,
create required number of and re-use that, to avoiding possible memory lacks
then you have to call setVisible(false) and setVisible(true)
JWindow missed methods for setting setDefaultCloseOperation(Whatever);
3) if you'll create constructor public JWindow(Frame owner), then you'll call directly
SwingUtilities.getAccessibleChildrenCount() and SwingUtilities.getWindowAncestor()
import javax.swing.*;
import java.awt.*;
public class Testing {
private JFrame f = new JFrame("Main Frame");
private JWindow splashScreen = new JWindow();
public Testing() {
splashScreen = new JWindow(f);
splashScreen.getContentPane().setLayout(new GridBagLayout());
JLabel label = new JLabel("Splash Screen");
label.setFont(label.getFont().deriveFont(96f));
splashScreen.getContentPane().add(label, new GridBagConstraints());
splashScreen.pack();
splashScreen.setLocationRelativeTo(null);
splashScreen.setVisible(true);
new Thread(new Runnable() {
#Override
public void run() {
readDatabase();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
}
}).start();
}
public void readDatabase() {
//simulate time to read/load data - 10 seconds?
try {
Thread.sleep(2000);
} catch (Exception e) {
e.printStackTrace();
}
}
public void createAndShowGUI() {
JLabel label = new JLabel("My Frame");
label.setFont(label.getFont().deriveFont(96f));
f.add(label);
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.pack();
f.setVisible(true);
System.out.println("JFrame getAccessibleChildrenCount count -> "
+ SwingUtilities.getAccessibleChildrenCount(f));
System.out.println("JWindow getParent -> "
+ SwingUtilities.getWindowAncestor(splashScreen));
splashScreen.dispose();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
Testing t = new Testing();
}
});
}
}

I did not go really into your design. but there is 'j.dispose();'.
this should work. here is the java documentation.
notice:
dispose(); - deletes the window from memory.
setVisibilty(false); - just hides it from the screen.
You can override the 'dispose()' function to do some stuff while the widow is closing (updating scores if its a game) but at the end of the overriden function you have to call 'super.dispose();' so the function of the class Window is called.

And the MainGame was a dialog window
But thats not what your code uses. You use a JWindow.
You should be using a JDialog for a modal window. Then you just dispose() the window.