Develop Reference

Removing components not updating JPanel/JFrame [duplicate]

Recently I asked here how to add a new JPanel to JFrame. The answer helped me to get a working code. But not I have a related question: "How can I remove an old JPanel". I need that because of the following problem.
A new JPanel appears appears when I want (either time limit is exceeded or user press the "Submit" button). But in several seconds some element of the old JPanel appears together with the component of the new JPanel. I do not understand why it happens.
I thought that it is because I have to other threads which update the window. But the first thread just add the old panel once (so, it should be finished). And in the second thread I have a loop which is broken (so, it also should be finished).
Here is my code:
private Thread controller = new Thread() {
public void run() {
// First we set the initial pane (for the selection of partner).
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.getContentPane().add(generatePartnerSelectionPanel());
frame.invalidate();
frame.validate();
}
});
// Update the pane for the selection of the parnter.
for (int i=40; i>0; i=i-1) {
final int sec = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
timeLeftLabel.setText(sec + " seconds left.");
}
});
try {
Thread.sleep(1000);
} catch (InterruptedException e) { }
if (partnerSubmitted) {
break;
}
}
// For the given user the selection phase is finished (either the time is over or form was submitted).
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.getContentPane().add(generateWaitForGamePanel());
frame.invalidate();
frame.validate();
}
});
}
};

Its the same whether you do add or remove a component on a visible GUI:
panel.remove(...);
panel.add(...);
panel.revalidate();
panel.repaint();

the easiest way to remove a component (panel) from a container (frame) is to keep a reference to it, and then call Container.remove(Component) ie:
private Thread controller = new Thread() {
public void run() {
final Component panel1 = generatePartnerSelectionPanel();
// First we set the initial pane (for the selection of partner).
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.getContentPane().add(panel1);
frame.invalidate();
frame.validate();
}
});
// Update the pane for the selection of the parnter.
for (int i=40; i>0; i=i-1) {
final int sec = i;
SwingUtilities.invokeLater(new Runnable() {
public void run() {
timeLeftLabel.setText(sec + " seconds left.");
}
});
try {Thread.sleep(1000);} catch (InterruptedException e) {}
if (partnerSubmitted) {break;}
}
// For the given user the selection phase is finished (either the time is over or form was submitted).
SwingUtilities.invokeLater(new Runnable() {
public void run() {
frame.getContentPane().remove(panel1);
frame.getContentPane().add(generateWaitForGamePanel());
frame.invalidate();
frame.validate();
}
});
}
};
i haven't tested this code but it should work.

I had problems with requestFocusInWindow on TextField too. The trick is to not construct the components in the JPanel constructor. But, make a build method and execute following code after it has been added to the frame.
This worked for me:
frame.getContentPane().removeAll(); //or .remove(previousPanel);
frame.getContentPane().add(newPanel);
panel.buildPanel(); // panel needs a builder method
frame.revalidate(); // in- and validate in one !!
frame.pack(); //
if you want to resize, you need preferredSize(); on panel or use repaint() if you don't need to resize frame.

Roman, the problem can be solved like that:
Do this in the beginning of your run method:
final JPanel partnerSelectionPanel = generatePartnerSelectionPanel();
Then do this
frame.getContentPane().add(partnerSelectionPanel);
Before you add the new panel do this:
partnerSelectionPanel.setVisible(false);
It works. I do not know if it is a safe and/or elegant solution but it works.

JFrame displays content only after resizing (Xuggler)

I Have written a listener for an IMediaReader from Xuggler.
It should show a video in a JPanel what i can add to a JFrame.
I have created this JFrame in the class main:
class Window extends JFrame {
static IMediaReader reader;
static Window main;
public static void main(String[] args) {
new Thread() {
public void run() {
reader = ToolFactory.makeReader("C:/Users/André/Desktop/Detail.wmv");
reader.addListener(new Player(IMediaViewer.Mode.AUDIO_VIDEO, main));
while (reader.readPacket() == null)
do {} while(false);
}
}.start();
SwingUtilities.invokeLater(new Runnable() {
public void run() {
main = new Window();
}
});
}
private Window() {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
setVisible(true);
setSize(700, 700);
}
});
}
// invoked by Player with the video panel
public void add(final JPanel videoPanel) {
add(videoPanel, BorderLayout.CENTER);
}
}
It shows the video but it only works when i resize the window manually and that is my problem. Else, it shows a small black square.
Using pack() instead of setSize() or invoke repaint doesn't help.
The Code of class Player isn't just from me. I've just changed some things:
public class Player extends MediaListenerAdapter implements IMediaListener, IMediaViewer {
private static Main main;
Player(Mode mode, Main main) {
setMode(mode);
Player.main = main;
}
#Override
public void onAddStream(IAddStreamEvent event)
{
[...]
MediaFrame frame = new MediaFrame(stream, this, main);
[...]
}
#Override
public void onVideoPicture(IVideoPictureEvent event)
{
MediaFrame frame = mFrames.get(event.getStreamIndex());
frame.setVideoImage(event.getPicture(), event.getImage());
}
static class PositionFrame extends JPanel
{
public PositionFrame(Player viewer, Main main)
{
main.add(this);
mFrames.add(this);
}
protected void adjustSize()
{
invalidate();
}
}
private class MediaFrame extends PositionFrame
{
// the video image
private BufferedImage mImage;
// the video panel
private final JPanel mVideoPanel;
// the stream
private final IStream mStream;
// the index of the stream (incase it's closed)
private final int mStreamIndex;
/**
* Construct a media frame.
*
* #param defaultCloseOperation what should Swing do if the window
* is closed. See the {#link javax.swing.WindowConstants}
* documentation for valid values.
* #param stream the stream which will appear in this frame
* #param viewer containing media viewer
*/
public MediaFrame(IStream stream,
Player viewer, Main main)
{
super(viewer, main);
// get stream and set title based it, establish a copy of the
// stream since it lives in a separate thread
mStream = stream.copyReference();
mStreamIndex = mStream.getIndex();
// the panel which shows the video image
mVideoPanel = new JPanel()
{
public void paint(Graphics graphics)
{
paintPanel((Graphics2D) graphics);
}
};
// add the videoPanel
add(mVideoPanel);
// show the frame
setVisible(true);
}
// set the video image
protected void setVideoImage(IVideoPicture picture, BufferedImage image)
{
[...]
}
protected void paintPanel(Graphics2D graphics)
{
if (mImage != null)
graphics.drawImage(mImage, 0, 0, null);
}
}
}
It is made up from the class MediaViewer
http://code.google.com/p/xuggle/source/browse/trunk/java/xuggle-xuggler/src/com/xuggle/mediatool/MediaViewer.java?r=644
EDIT: If I do it like this, it doesn't work without resizing manually.
I'm not shure if I have unterstood you right.

You have this code in two places.
pack();
setSize(700, 700);
The pack() class is wasteful since you are setting the size immediately afterwards. Also, the first time you call in your constructor you haven't even added anything yet.
Try setting the size or calling pack after you have added the video component and after you have made the frame visible.
Based on your edits, I believe the issue is that you are setting the frame visible before the component is in place. Move your setVisible and pack() calls to the end of your constructor for the Main class instead of the add() method.
Based on more edits to your question: As I mentioned in the comments, make sure you separate off the GUI code in a separate call to invokeLater to get things happening on the EDT. Therefore you need to move your IMediaReader creation and thread starting into your main() method, then after that create a new call to SwingUtilities.invokeLater that creates a new Main, class. By the way, Main is a confusing name for a class.

Reconstruct JFrame after using dispose by static method in nested static class

I have a public class AppHelper for displaying some help content using a jframe. There is an exit button on the same JFrame which on click disposes the jframe.
The ActionListener is implemented as a static nested class of the class mentioned above.
Also all the components of the help window are defined in the outer class and all of them are private and static. Also the method that shows the help window is static.
Here is some code that I have implemented:
public class AppHelper {
// helper frame
private static JFrame appHelperFrame;
// helper panel
private static JPanel appHelperPanel;
// helper pane
private static JEditorPane appHelperPane;
// exit helper button
private static JButton exitAppHelperButton;
// constraints
private static GridBagConstraints appHelperPaneCons, exitAppHelperButtonCons;
/**
set layout
*/
private static void setLayoutConstraints () {
// defines layout
}
/**
* initialize the helper elements
* #param void
* #return void
*/
public static void initializeElements () {
// initialize constraints
setLayoutConstraints();
// handler
AppHelper.AppHelperHandler appHelpHandler = new AppHelper.AppHelperHandler();
appHelperFrame = new JFrame("App Help");
appHelperPanel = new JPanel();
appHelperPanel.setLayout(new GridBagLayout());
appHelperPane = new JEditorPane();
exitAppHelperButton = new JButton("Exit");
exitAppHelperButton.addActionListener(appHelpHandler);
java.net.URL helpURL = null;
try {
helpURL = new File("AppHelp.html").toURI().toURL();
} catch (MalformedURLException ex) {
Logger.getLogger(AppHelper.class.getName()).log(Level.SEVERE, null, ex);
}
try {
appHelperPane.setPage(helpURL);
} catch (IOException ex) {
Logger.getLogger(AppHelper.class.getName()).log(Level.SEVERE, null, ex);
}
appHelperPane.setEditable(false);
appHelperFrame.add(appHelperPanel);
appHelperPanel.add(appHelperPane, appHelperPaneCons);
appHelperPanel.add(exitAppHelperButton, exitAppHelperButtonCons);
appHelperFrame.setSize(350, 400);
appHelperFrame.setResizable(false);
appHelperFrame.setVisible(true);
}
/**
* TODO
*/
public static void showAboutApp() {
//throw new UnsupportedOperationException("Not yet implemented");
}
/**
*
* Acts as the handler for the help window components
* Implement actionListener interface.
*/
private static class AppHelperHandler implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if(source == exitAppHelperButton) {
appHelperFrame.dispose();
}
}
}
}
The reason of disposing the JFrame instead of setting it invisible is that I dont want this JFrame to consume memory when this JFrame is not in use.
Now the problem is first time I click on the help button (on some other window) the JFrame is shown. Now when I click the exit button on this help window the JFrame is disposed by the handler. Next time I again click on the help button, the help window is not shown. I wanted to know if there is any error in my code or I need to do some thing else.

The javadoc of Window.dispose() states that
The Window and its subcomponents can be made displayable again by rebuilding the native resources with a subsequent call to pack or show.
And that works too, I've tried it. Just call appHelperFrame.setVisible(true) and that's all. If the window is not activated, try calling appHelperFrame.setState(Frame.NORMAL) which will acitvate it.
You only have to call your initializeElements method once though. Your showAboutApp() method should look something like this:
public static void showAboutApp() {
if (appHelperFrame == null)
initializeElements(); // This also makes the frame visible
else {
appHelperFrame.setVisible(true);
appHelperFrame.setState(Frame.NORMAL);
}
}
Final note:
If you always call this showAboutApp() from the EDT (Event Dispatching Thread) then you're good. If you call this from multiple threads, you might want to execute it in the EDT with like SwingUtilities.invokeAndwait() or SwingUtilities.invokeLater() which also ensures synchronization between multiple threads.

How do I make a thread wait for JFrame to close in Java?

When the program starts, a new JFrame is created. Once the user clicks the start button a thread is created and started. Part of this threads execution is to validate the data on the form and then execute with that data. Once the data has been validated the thread calls dispose() on the original frame and then creates a new JFrame that acts as a control panel.
There is also an automatic mode of the program that doesn't display any GUI at all, this mode reads data from a configuration file and then starts the execution thread and runs everything but without the control panel.
I want the program to end once the thread completes, but in GUI mode, only if the user has closed the control panel as well.
Is it possible to make the thread wait for the frame to close. I assuming that the frame is run from it's own Thread? or is that not the case.
Thanks.

The answer you chose is a little awkward. Using Thread.sleep(1000) will check for window state every second. It is not a performance issue, but just bad coding style. And you may have a one second response time.
This code is a little bit better.
private static Object lock = new Object();
private static JFrame frame = new JFrame();
/**
* #param args
*/
public static void main(String[] args) {
frame.setSize(300, 300);
frame.setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
frame.setVisible(true);
Thread t = new Thread() {
public void run() {
synchronized(lock) {
while (frame.isVisible())
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("Working now");
}
}
};
t.start();
frame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosing(WindowEvent arg0) {
synchronized (lock) {
frame.setVisible(false);
lock.notify();
}
}
});
t.join();
}

You can make reference from your thread to the JFrame. Then set the default close operation of JFrame to HIDE_ON_CLOSE. If the JFrame is closed, you can stop the thread.
Example code:
import java.awt.Dimension;
import javax.swing.JFrame;
public class FrameExample extends JFrame {
public FrameExample() {
setSize(new Dimension(100, 100));
setDefaultCloseOperation(HIDE_ON_CLOSE);
setVisible(true);
}
private static class T implements Runnable {
private FrameExample e;
public T(FrameExample e) {
this.e = e;
}
#Override
public void run() {
while (true) {
if (e.isVisible()) {
// do the validation
System.out.println("validation");
try {
Thread.sleep(1000);
} catch (InterruptedException e1) {
break;
}
}
}
}
}
public static void main(String[] args) {
FrameExample frameExample = new FrameExample();
new Thread(new T(frameExample)).start();
}
}

All Swing components, including JFrame, are managed by a single thread, called the Event Dispatch Thread, or EDT. (It's possible to call methods on Swing objects from other threads, but this is usually unsafe, except in a few cases not relevant here.)
You'll probably accomplish what you want here by putting the data validation and execution code in its own object which is otherwise completely unaware of the outside world. Then, call it from one of two other objects: one that manages a GUI, and another that runs in "automatic mode".

Why wont my JFrame hide?

I'm in the process of creating a GUI in Netbeans 6.1 for my senior design project but i've run into an annoying snag. Temporary Windows like my login PopUp and others wont disappear when i tell it. I've been researching how to solve this for about 2 months on an off. I've even mad a separate thread for my Pop Up but it still wont work....the only way it will disappear if i literally dont mess with any of the other GUI components....my sample code should help describe my anger...dont mind the shadow code, it was for testing purposes, which obviously didnt help.
//This method is called once a user presses the "first" login button on the main GUI
public synchronized void loginPopUpThread() {
doHelloWorld = new Thread(){
#Override
public synchronized void run()
{
try
{
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
System.out.println("waitin");
doHelloWorld.wait();
System.out.println("Not Sleepin..");
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(false);
}
catch (InterruptedException e)
{
}
}
};
doHelloWorld.start();
//This is called when the "second" loginB is pressed and the password is correct...
public synchronized void notifyPopUp() {
synchronized(doHelloWorld) {
doHelloWorld.notifyAll();
System.out.println("Notified");
}
}
I've also tried Swing Utilities but maybe i implemented it wrong as it's my first time using them. It essentially does the same thing as the code above except the window freezes when it gets to wait, which the above code doesnt do:
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public synchronized void run() {
try
{
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
System.out.println("waitin");
wait();
System.out.println("Not Sleepin.");
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(false);
}
catch (InterruptedException e)
{
}
}
});
PLEASE HELP ME!!!

Rules of thumb:
Don't manipulate GUI components in arbitrary threads; always arrange to manipulate them in the event thread
Never wait or sleep inside the event thread (so, never inside code sent to invokeLater())
So the answer to how you solve this problem is "some other way"...
Standing back from the problem a bit, what is it you're actually trying to do? If you just want a login dialog to wait for the user to enter user name and password, is there a reason not to just use a modal JDialog (after all, that's what it's there for...).
If you really do want some arbitrary thread to wait for a signal to close the window/manipulate the GUI, then you need to do the waiting in the other thread, and then make that thread call SwingUtilities.invokeLater() with the actual GUI manipulation code.
P.S. There are actually some GUI manipulation methods that it is safe to call from other threads, e.g. calls that are "just setting a label" are often safe. But which calls are safe isn't terribly well-defined, so it's best just to avoid the issue in practice.

The Swing components should only be manipulated by the swing event dispatch thread.
class SwingUtilites has methods to submit tasks to the dispatch thread.

It is difficult to diagnose your problem. I'm not sure what you're trying to do with the wait methods, but I recommend leaving wait/notify alone.
This code has two frames - when you create a second frame, the first is hidden until you close it.
public class SwapFrames {
private JFrame frame;
private JFrame createMainFrame() {
JButton openOtherFrameButton = new JButton(
"Show other frame");
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contentPane = frame.getContentPane();
contentPane.setLayout(new FlowLayout());
contentPane.add(openOtherFrameButton);
frame.pack();
openOtherFrameButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
onClickOpenOtherFrame();
}
});
return frame;
}
private void onClickOpenOtherFrame() {
frame.setVisible(false);
JFrame otherFrame = new JFrame();
otherFrame
.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
otherFrame.setContentPane(new JLabel(
"Close this to make other frame reappear."));
otherFrame.pack();
otherFrame.setVisible(true);
otherFrame.addWindowListener(new WindowAdapter() {
#Override
public void windowClosed(WindowEvent e) {
frame.setVisible(true);
}
});
}
public static void main(String[] args) {
JFrame frame = new SwapFrames().createMainFrame();
frame.setVisible(true);
}
}
Because I don't see any evidence of them in your code, I'm going to suggest you read up on using event listeners rather than trying to "wait" for code to finish.
It isn't entirely clear what you're trying to achieve, but you might be better off with a modal dialog:
public class DialogDemo {
public JFrame createApplicationFrame() {
JButton openDialogButton = new JButton("Open Dialog");
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container container = frame.getContentPane();
container.setLayout(new FlowLayout());
container.add(openDialogButton);
frame.pack();
openDialogButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
onOpenDialog(frame);
}
});
return frame;
}
private void onOpenDialog(JFrame frame) {
JDialog dialog = createDialog(frame);
dialog.setVisible(true);
}
private JDialog createDialog(JFrame parent) {
JButton closeDialogButton = new JButton("Close");
boolean modal = true;
final JDialog dialog = new JDialog(parent, modal);
dialog
.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
Container container = dialog.getContentPane();
container.add(closeDialogButton);
dialog.pack();
dialog.setLocationRelativeTo(parent);
closeDialogButton
.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
dialog.setVisible(false);
}
});
return dialog;
}
public static void main(String[] args) {
new DialogDemo().createApplicationFrame().setVisible(
true);
}
}

How about doing simply:
//This method is called once a user presses the "first" login button on the main GUI
public void loginPopUpThread() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
loginPopUpFrame.pack();
loginPopUpFrame.setVisible(true);
}
};
}
//This is called when the "second" loginB is pressed and the password is correct...
public void notifyPopUp() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
loginPopUpFrame.setVisible(false);
}
};
}

What you really want to be using is a modal JDialog.
Note, bits of this are left out. It's your homework/project.
public void actionPerformed(ActionEvent e)
{
// User clicked the login button
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
LoginDialog ld = new LoginDialog();
// Will block
ld.setVisible(true);
}
});
}
public class LoginDialog extends JDialog
{
public LoginDialog()
{
super((Frame)null, "Login Dialog", true);
// create buttons/labels/components, add listeners, etc
}
public void actionPerformed(ActionEvent e)
{
// user probably clicked login
// valid their info
if(validUser)
{
// This will release the modality of the JDialog and free up the rest of the app
setVisible(false);
dispose();
}
else
{
// bad user ! scold them angrily, a frowny face will do
}
}
}