I am trying to learn ProgressMonitor in Java Swing.
I created this simple test code -
public class ProgressMonitorTest extends JFrame
{
private JPanel contentPane;
private ProgressMonitor progressMonitor;
private JButton button;
private static ProgressMonitorTest frame;
private static boolean isFrameReady;
public JButton getButton()
{
return button;
}
public ProgressMonitor getProgressMonitor()
{
return progressMonitor;
}
/**
* Launch the application.
*/
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
try
{
frame = new ProgressMonitorTest();
frame.setVisible(true);
isFrameReady = true;
}
catch (Exception e)
{
e.printStackTrace();
}
}
});
while(!isFrameReady)
{
//
}
frame.getButton().addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
try
{
for(int i=0;i<=10;i++)
{
final int percent = i;
SwingUtilities.invokeAndWait(new Runnable()
{
#Override
public void run()
{
frame.getProgressMonitor().setProgress(percent * 10);
frame.getProgressMonitor().setNote("Completed " + percent*10 + "%.");
}
});
try
{
Thread.sleep(1000);
}
catch(Exception ee)
{
//
}
}
}
catch(Exception es)
{
//
}
}
});
}
/**
* Create the frame.
*/
public ProgressMonitorTest()
{
isFrameReady = false;
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
setTitle("Progress Monitor");
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
progressMonitor = new ProgressMonitor(frame, "Update in progress...", "", 0, 10);
button = new JButton("Click Here");
contentPane.add(button);
setContentPane(contentPane);
}
}
A few questions regarding this-
If I remove the isFrameReady check, the program says a NullPointerException at the line where I assign the button's action listener.
If I keep the above check, then clicking on the button does nothing.
Keeping the above check and then debugging this, I let it wait for some time before it gets to the line where the action listener. In this case, it works but immediately quits saying it can't call invokeAndWait from the event handling thread.
What am I missing in all this ? Can someone explain how to get this to work.
If I remove the isFrameReady check, the program says a
NullPointerException at the line where I assign the button's action
listener.
your use of isFrameReady ensures that you have created your frame successfully. inside your main, your posted request to event dispatch thread(EDT) using call EventQueue.invokeLater(new Runnable(){}): removing the check isFrameReady, you were going to call frame.getButton() in main thread but the frame have not been yet created by frame = new ProgressMonitorTest(); in the EDT and thus a NullPointerException occurs.
If I keep the above check, then clicking on the button does nothing.
you should understand by now, that above check is nothing to do with button click. The button is not doing anything because the GUI got freezed for violating swing's single threading rule. Put your incrementing for loop of the actionPerformed method inside another thread as the following code fragement shows and execute it from there. you will see that it works fine.
new Thread(){
public void run()
{
for(int i=0; i<10; i++)
{
//whatever you were doing.
}
}
}.start();
Keeping the above check and then debugging this, I let it wait for
some time before it gets to the line where the action listener. In
this case, it works but immediately quits saying it can't call
invokeAndWait from the event handling thread.
SwingUtitlies.invokeAndWait() blocks the current thread and waits until the EDT is done executing the task given to it. As actionPerformed() function is already running inside EDT, so calling SwingUtitlies.invokeAndWait() from the current thread:EDT would block the current thread:EDT which should not be allowed. Don't use invokeAndWait for this case. you should call SwingUtilities.invokeLater() instead.
However I don't think you will get anything until you understand Swing threading model. Read the javadoc and some internet resource. DO HAVE The book Filthy Rich Clients and try the example the book offered: You will have a greater knowledge in graphical effects then any other resource can provide.
Related
I wrote a java program and made a GUI (my first one jeej).
This is my main methode:
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ui frame = new ui();
frame.setVisible(true);
} catch (Exception e) {
ui.log("Something went wrong: " + e.getMessage());
}
}
});
}
The methode ui.log let's me write to a textArea.
My gui has one button which starts a pretty long methode which takes several minutes to complete.
In this long methode I want to be able to log to my textArea using ui.log().
It works, but It is only displayed when the methode ends and I want to see the results while the methode is running.
Both the button and the buttonEvent listener are made inside new ui();
JButton btnNewButton = new JButton("button1");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
thveryLongMethodeThatIwantToLogDuringExecution();
}
});
Does anyone knows how I can log while the methode is running?
EDIT: I think it has something to do with threads but I'm not sure. I never done something with threads.
Don't perform your work on the EDT. Use the javax.swing.SwingWorker to run time-consuming background tasks.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
using sleep() for a single thread
I'm having issues with JTextField.setText() when using Thread.sleep(). This is for a basic calculator I'm making. When the input in the input field is not of the correct format I want "INPUT ERROR" to appear in the output field for 5 seconds and then for it to be cleared. The setText() method did work when I just set the text once to "INPUT ERROR" and by printing out the text in between I found it does work with both that and the setText("") one after the other. The problem arises when I put the Thread.sleep() between them.
Here's a SSCCE version of the code:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.regex.Pattern;
import javax.swing.*;
public class Calc {
static Calc calc = new Calc();
public static void main(String args[]) {
GUI gui = calc.new GUI();
}
public class GUI implements ActionListener {
private JButton equals;
private JTextField inputField, outputField;
public GUI() {
createFrame();
}
public void createFrame() {
JFrame baseFrame = new JFrame("Calculator");
baseFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel contentPane = new JPanel();
BoxLayout layout = new BoxLayout(contentPane, BoxLayout.Y_AXIS);
contentPane.setLayout(layout);
baseFrame.setContentPane(contentPane);
baseFrame.setSize(320, 100);
equals = new JButton("=");
equals.addActionListener(this);
inputField = new JTextField(16);
inputField.setHorizontalAlignment(JTextField.TRAILING);
outputField = new JTextField(16);
outputField.setHorizontalAlignment(JTextField.TRAILING);
outputField.setEditable(false);
contentPane.add(inputField);
contentPane.add(outputField);
contentPane.add(equals);
contentPane.getRootPane().setDefaultButton(equals);
baseFrame.setResizable(false);
baseFrame.setLocation(100, 100);
baseFrame.setVisible(true);
}
/**
* When an action event takes place, the source is identified and the
* appropriate action is taken.
*/
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == equals) {
inputField.setText(inputField.getText().replaceAll("\\s", ""));
String text = inputField.getText();
System.out.println(text);
Pattern equationPattern = Pattern.compile("[\\d(][\\d-+*/()]+[)\\d]");
boolean match = equationPattern.matcher(text).matches();
System.out.println(match);
if (match) {
// Another class calculates
} else {
try {
outputField.setText("INPUT ERROR"); // This doesn't appear
Thread.sleep(5000);
outputField.setText("");
} catch (InterruptedException e1) {
}
}
}
}
}
}
I'm not actually using a nested class but I wanted it to be able to be contained in one class for you. Sorry about how the GUI looks but again this was to cut down the code. The the important section (if (e.getSource() == equals)) remains unchanged from my code. The simplest way to give an incorrect input is to use letters.
When you use Thread.sleep() you're doing it on the main thread. This freezes the gui for five seconds then it updates the outputField. When that happens, it uses the last set text which is blank.
It's much better to use Swing Timers and here's an example that does what you're trying to accomplish:
if (match) {
// Another class calculates
} else {
outputField.setText("INPUT ERROR");
ActionListener listener = new ActionListener(){
public void actionPerformed(ActionEvent event){
outputField.setText("");
}
};
Timer timer = new Timer(5000, listener);
timer.setRepeats(false);
timer.start();
}
As Philip Whitehouse states in his answer, you are blocking the swing Event Dispatch Thread with the Thread.sleep(...) call.
Given that you've taken the time to set up an ActionListener already, it would probably be easiest to use a javax.swing.Timer to control clearing the text. To do this, you could add a field to your GUI class:
private Timer clearTimer = new Timer(5000, this);
In the constructor for GUI, turn off the repeats feature, as you really only need a one-shot:
public GUI() {
clearTimer.setRepeats(false);
createFrame();
}
Then, actionPerformed can be modified to use this to start the timer/clear the field:
public void actionPerformed(ActionEvent e) {
if (e.getSource() == equals) {
inputField.setText(inputField.getText().replaceAll("\\s", ""));
String text = inputField.getText();
System.out.println(text);
Pattern equationPattern = Pattern.compile("[\\d(][\\d-+*/()]+[)\\d]");
boolean match = equationPattern.matcher(text).matches();
System.out.println(match);
if (match) {
// Another class calculates
} else {
clearTimer.restart();
outputField.setText("INPUT ERROR"); // This doesn't appear
}
} else if (e.getSource() == clearTimer) {
outputField.setText("");
}
}
You're doing a Thread.sleep() in the Swing main thread. This is NOT good practice. You need to use a SwingWorker thread at best.
What's happening is that it's running the first line, hitting Thread.sleep().
This prevents the (main) EDT thread from doing any of the repaints (as well as preventing the next line executing).
You should use a javax.swing.Timer to setup the delayed reaction and not put sleep() calls in the main thread.
I have a class (called Class_GUI) which has a panel with lots of buttons on it. Class_GUI has some methods that change the text and colour of the buttons.
I have also have a program with the actionPerformed method. When this is called it creates an instance of Class_GUI and repeatedly calls Class_GUI methods, changing the buttons etc.
The issue I'm having is that the buttons only display properly once the actionPerformed method has finished entirely whereas I want it to change after each Class_GUI method is called.
My attempt so far is in each Class_GUI method I do this at the end of the method:
SwingUtilities.invokeLater(Refresh_GUI);
Where Refresh_GUI is defined:
Runnable Refresh_GUI = new Runnable(){
public void run(){
frame.revalidate();
frame.repaint();
}
};
Assuming that your actionPerformed method is being called within the context of the Event Dispatching Thread, no UI updates will occur until AFTER the actionPerformed method has competed, even using SwingUtilities#invokeLater won't change that, because until the actionPerformed method exits, the EDT won't be able to continue processing (amongst other things) repaint requests.
The best you can do, is start a second thread and from within that thread, update your UI components...but, you area going to be forced to use SwingUtilities#invokeLater as you should NEVER update any UI component outside the EDT.
The advantage though, is that the thread does not need to compete in order for the EDT to start processing the repaint request
UPDATED with Example
public class SwingThreadUpdate {
public static void main(String[] args) {
new SwingThreadUpdate();
}
public SwingThreadUpdate() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new BlinkPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class BlinkPane extends JPanel {
private JLabel label;
private JButton button;
public BlinkPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridy = 0;
label = new JLabel("Blinky");
label.setBackground(Color.RED);
button = new JButton("Click me");
add(label, gbc);
gbc.gridy++;
add(button, gbc);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button.setEnabled(false);
new Thread(new BlinkTask(BlinkPane.this)).start();
}
});
}
private void setBlink(boolean blink) {
label.setOpaque(blink);
}
private void reset() {
button.setEnabled(true);
label.setOpaque(false);
}
}
public class BlinkTask implements Runnable {
private BlinkPane blinkPane;
protected BlinkTask(BlinkPane blinkPane) {
this.blinkPane = blinkPane;
}
#Override
public void run() {
Blink blinkOn = new Blink(blinkPane, true);
Blink blinkOff = new Blink(blinkPane, false);
for (int index = 0; index < 10; index++) {
if (index % 2 == 0) {
SwingUtilities.invokeLater(blinkOn);
} else {
SwingUtilities.invokeLater(blinkOff);
}
try {
Thread.sleep(125);
} catch (InterruptedException ex) {
}
}
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
blinkPane.reset();
}
});
}
}
public class Blink implements Runnable {
private BlinkPane blinkPane;
private boolean blink;
public Blink(BlinkPane blinkPane, boolean blink) {
this.blinkPane = blinkPane;
this.blink = blink;
}
#Override
public void run() {
blinkPane.setBlink(blink);
blinkPane.repaint();
}
}
}
You might like to have a read through Painting in AWT and Swing for more information.
Incase your actionPerform method calls code to update buttons in a for loop you could also add the updation code in the invokeLater that way both the updation and painting code will run one by one. Invoke later will execute only after current method completes its execution so only way to ensure painting happens faster is to break your tasks into smaller peices.
First, make sure you are only accessing any GUI components from the Event Dispatch thread (via invokeLater or as part of handling a GUI event).
Second, if you change any properties of a GUI component, it should automatically post an event to repaint itself. If not you can try invoking component.repaint(). But it's critical that the changes to the component properties happen on the EDT.
A simple solution is execute the entire ActionPerformed event less task to clean the screen at the end of the event queue.
So, first it executes the cleanScreen() function because the rest of the event waits for all events finish.
AnyButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
cleanScreen(); //Modify components before action performer event
EventQueue.invokeLater( new Runnable() {
#Override public void run() {
anytask(); //Action performer event
}
});
}
});
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".
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
}
}
}