I want to display a "loading message" when a process is started and I want to change the message when the process is finished. I tried to update the text from a JLabel before and after the thread with the process is started but the problem is that on the frame appears only the last update.
Here is my code:
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class MyClass extends JFrame {
private JLabel loading;
private JButton jButton;
private JPanel jPanel;
public static void main(String[] args) {
new MyClass();
}
MyClass() {
jPanel = new JPanel();
setLayout(new GridLayout(0, 1));
loading = new JLabel("");
loading.setVisible(true);
jButton = new JButton("Click me!");
addActionToJButon();
setSize(300, 300);
jPanel.add(jButton);
jPanel.add(loading);
add(jPanel);
setVisible(true);
}
private void addActionToJButon() {
jButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
loading.setText("Loading....");
new Thread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
for (int i = 0; i <= 1000000; i++) {
System.out.println(i);
}
}
}).start();
loading.setText("Done!");
}
});
}
}
I was expecting to appear the label "Loading..." once what the process is started and the message "Done" when the process is finished but I can't find out why on the frame appears the label with the message "Done!".
Thanks to JB Nizet advices I used SwingWorker and the code is working now.
Here is the correct code:
package view;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.ExecutionException;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingWorker;
public class MyClass extends JFrame {
private JLabel loading;
private JButton jButton;
private JPanel jPanel;
public static void main(String[] args) {
new MyClass();
}
MyClass() {
jPanel = new JPanel();
setLayout(new GridLayout(0, 1));
loading = new JLabel("");
loading.setVisible(true);
jButton = new JButton("Click me!");
addActionToJButon();
setSize(300, 300);
jPanel.add(jButton);
jPanel.add(loading);
add(jPanel);
setVisible(true);
}
private void addActionToJButon() {
jButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
loading.setText("Loading....");
swingWorker();
}
});
}
private void swingWorker() {
SwingWorker worker = new SwingWorker<String, String>() {
#Override
protected String doInBackground() throws Exception {
// TODO Auto-generated method stub
for (int i = 0; i <= 1000000; i++) {
System.out.println(i);
}
return "Done";
}
protected void done() {
try {
String finished = get();
loading.setText(finished);
} catch (InterruptedException | ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
worker.execute();
}
}
Because you are doing your "loading" within a thread, and you are setting your loading text outside the thread, you immediately set loading to "Done!" when you begin loading. What you want to do is set loading within your run() function like this:
private void addActionToJButon() {
jButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
new Thread(new Runnable() {
#Override
public void run() {
loading.setText("Loading....");
// TODO Auto-generated method stub
for (int i = 0; i <= 1000000; i++) {
System.out.println(i);
}
loading.setText("Done!");
}
}).start();
}
});
}
Related
I am trying to capture the moment a user finished resizing a JFrame through the mouse drag of a frame corner. I have so far found the below options, but they both print BLAH again and again until I am done stretching the window size. I only want it to print BLAH once I released the mouse after the continuous dragging of the JFrame corner resizing it. Any thoughts?
frame.addComponentListener(new ComponentAdapter()
{
public void componentResized(ComponentEvent evt) {
Component c = (Component)evt.getSource();
System.out.println("BLAH");
}
});
AND
frame.addComponentListener(new ComponentListener() {
#Override
public void componentShown(ComponentEvent e) {
// TODO Auto-generated method stub
}
#Override
public void componentResized(ComponentEvent e) {
// TODO Auto-generated method stub
System.out.println("BLAH");
}
#Override
public void componentMoved(ComponentEvent e) {
// TODO Auto-generated method stub
}
#Override
public void componentHidden(ComponentEvent e) {
// TODO Auto-generated method stub
}
}
);
The core problem is, you're unlikely to be able to detect when a mouse event occurs on the frame decorations, as it tends to be handled at a much lower level.
One trick I've used in the past, is to use a short lived, single run, Swing Timer, which is restarted each time componentResized is called. This means that the Timer will only trigger AFTER a "short delay" after componentResized stops been called, for example
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JLabel label;
private Timer resizeTimer;
public TestPane() {
setLayout(new GridBagLayout());
label = new JLabel(".......");
add(label);
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
if (resizeTimer == null) {
resizeTimer = new Timer(250, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
label.setText(getSize().width + "x" + getSize().getHeight());
resizeTimer.stop();
resizeTimer = null;
}
});
resizeTimer.setRepeats(false);
}
resizeTimer.restart();
}
});
}
}
}
I have made a very simple code to show it here, i have a button that should show a JDialog to check the progress status, i am using the invoke late to go through EDT and my loop isn't in the run method, so why isn't my bar updating ?
here is the code
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class JBarEx extends JFrame {
private JTextField progStatus = new JTextField("Undefined");
private JButton dialogBtn = new JButton("Show Progression dialog");
final JDialog dlg = new JDialog((JFrame) null, "prog Title", false);
final JProgressBar dpb = new JProgressBar(0, 100);
public JBarEx() {
JPanel pan = new JPanel();
dialogBtn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
showProgress();
}
});
progStatus.setEditable(false);
pan.add(progStatus);
pan.add(dialogBtn);
setContentPane(pan);
this.setSize(200, 100);
setVisible(true);
}
public void showProgress() {
dlg.add(BorderLayout.CENTER, dpb);
dlg.add(BorderLayout.NORTH, new JLabel("prog message"));
dlg.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
dlg.setSize(300, 75);
dlg.setLocationRelativeTo(null);
dlg.setVisible(true);
for (int i = 0; i < 100; i++) {
final int ii = i;
try {
Thread.sleep(25);
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
updateBar(ii);
}
});
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public void updateBar(int newValue) {
dpb.setValue(newValue);
}
public static void main(String[] args) {
JBarEx jbx = new JBarEx();
}
}
Your showProgress method is being executed within the context of the Event Dispatching Thread. The EDT is responsible for, amongst other things, processing paint requests. This means that so long as your for-loop is executing, the EDT can not process any new paint requests (or handle the invokeLater events either) as it is blocking the EDT.
While there are any number of possible ways to solve the problem, based on your code example, the simplest would be to use a SwingWorker.
It has the capacity to allow your to execute the long running task the a background thread (freeing up the EDT), but also allows you means for publishing updates (if required) so that they can be processed in the EDT and also provides handy progress notification.
For example...
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
public class SwingWorkerProgress {
public static void main(String[] args) {
new SwingWorkerProgress();
}
public SwingWorkerProgress() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JProgressBar pbProgress;
private JButton start;
public TestPane() {
setBorder(new EmptyBorder(10, 10, 10, 10));
pbProgress = new JProgressBar();
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.insets = new Insets(4, 4, 4, 4);
gbc.gridx = 0;
gbc.gridy = 0;
add(pbProgress, gbc);
start = new JButton("Start");
gbc.gridy++;
add(start, gbc);
start.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
start.setEnabled(false);
ProgressWorker pw = new ProgressWorker();
pw.addPropertyChangeListener(new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
String name = evt.getPropertyName();
if (name.equals("progress")) {
int progress = (int) evt.getNewValue();
pbProgress.setValue(progress);
repaint();
} else if (name.equals("state")) {
SwingWorker.StateValue state = (SwingWorker.StateValue) evt.getNewValue();
switch (state) {
case DONE:
start.setEnabled(true);
break;
}
}
}
});
pw.execute();
}
});
}
}
public class ProgressWorker extends SwingWorker<Object, Object> {
#Override
protected Object doInBackground() throws Exception {
for (int i = 0; i < 100; i++) {
setProgress(i);
try {
Thread.sleep(25);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
}
}
Check out Concurrency in Swing for more details
Even if you fix the loop as others have pointed out, you'd still block the event dispatch thread. The for loop is run in showProgress() which is called from an event listener. The updates are pushed to the event queue, but that does not get processed until the loop has completed.
Use a Swing Timer instead. Something like this:
Timer timer = new Timer(25, new ActionListener() {
private int position;
#Override
public void actionPerformed(ActionEvent e) {
position++;
if (position < lastPosition) {
updateBar(position);
} else {
((Timer) e.getSource).stop();
}
}
});
timer.start();
where lastPosition would be the state where you want the progress bar to stop.
Unrelated to that bug, but a bug still, you should not create swing components outside the event dispatch thread. It's best to do it right from the start:
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JBarEx jbx = new JBarEx();
}
});
}
for (int i = 0; i < 0; i++) {
You will never enter this code so will never call the updateBar(..) method
i needs to be greater than 0 in this case. If it is 1 then updateBar will be called once, if 2 then updateBar will be called twice etc
Also rather than doing
Thread.sleep(25);
take a look at java executors as these will help with your scheduling and remove the need for the sleep
I've tried many things to get this button bb or continue to output "Hey Buddy", yet it still does not work. It is displayed yet when i press it nothing happens. The code uses both java swing a awt.
package Game;
import java.awt.*;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Panel;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.TextEvent;
import java.awt.event.TextListener;
import java.util.concurrent.TimeUnit;
import javax.swing.JButton;
public class base extends java.applet.Applet implements ActionListener, TextListener {
//Graphics
//Graphics
#SuppressWarnings("deprecation")
public static JButton bb = new JButton("Continue");
public TextArea ta = new TextArea(30, 140);
TextArea tb = new TextArea(3, 130);
public int counter = 0;
//main class
public static void main(String[] args) {
Frame f = new Frame("---Quest---");
base ex = new base();
ex.init();
f.add("Center", ex);
f.pack();
f.show(true);
bb.addActionListener(ex);
}
public void actionPerformed1(ActionEvent Continue) {
bb.addActionListener(this);
counter++;
if (Continue.getSource() == bb && counter == 1) {
tb.append("Hey Buddy");
}
}
//graphics
public void init() {
bb.addActionListener(this);
Panel p;
setLayout(new BorderLayout());
p = new Panel();
ta.append("Hey");
bb.addActionListener(this);
p.add(bb);
p.add(ta);
p.add(tb);
p.setBackground(Color.blue);
ta.setBackground(Color.cyan);
ta.setEditable(false);
add("Center", p);
p.setVisible(true);
}
//time class
public static int nap(int time) {
try {
TimeUnit.SECONDS.sleep(time);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
//end of code
#Override
public void textValueChanged(TextEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
}
}
The whole code is buggy.Read the Comments inline.
1.Idk why you are adding actionListener to the button 4 times(Keep one)
2.You have to have to change the actionPerformed1 to actionPerfromed as you are implementing the ActionListener and assigning this to button's ActionListener
public TextArea ta = new TextArea(30, 140);
TextArea tb = new TextArea(3, 130);
public int counter = 0;
//main class
public static void main(String[] args) {
f.show(true);//show is deprecated use setVisible(true) instead;
bb.addActionListener(ex);//1
}
public void actionPerformed1(ActionEvent Continue) {//have to change the actionPerformed1 to actionPerfromed
bb.addActionListener(this);//2 What is this assigning inside actionPerformed Need to be removed
counter++;
if (Continue.getSource() == bb && counter == 1) {
tb.append("Hey Buddy");
}
}
//graphics
public void init() {
bb.addActionListener(this);//3
Panel p;
setLayout(new BorderLayout());
p = new Panel();
ta.append("Hey");
bb.addActionListener(this);//4
p.add(bb);
p.setVisible(true);//already called a show for JFrame why you want to set Visible of Panel
}
I am new to programming, and created a little program to practice code. It is an authentication program where you type in a username and password, and only my specified username and password will work to make it show a picture. I typed all the code, and there was no error; but when I ran it and typed in the username and password, it failed to show the picture. Here is my code.
package main.Swing.com;
//imports
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputMethodEvent;
import java.awt.event.InputMethodListener;
import java.awt.event.TextEvent;
import java.awt.event.TextListener;
import java.util.EventObject;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
//class that carries other classes and carries some variables
public class Main extends javax.swing.JFrame implements ActionListener, TextListener, InputMethodListener {
JButton Test = new JButton("TEST IF YOU HAVE ACCESS TO THIS");
JButton Cancel = new JButton("CANCEL");
JTextField username = new JTextField(15);
JTextField password = new JTextField(15);
String n = ("Nathan");
int nathannam;
int nathannamer;
JButton superman;
JButton supermanny;
//constructor class that has the jframe
public Main() {
super("Authenticator");
setSize(300, 220);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLookAndFeel();
//creating the pane and defining some labels
JPanel pane = new JPanel();
JLabel UsernameLabel = new JLabel("Username: ");
JLabel PasswordLabel = new JLabel("Password: ");
//adding all the components to the pane
pane.add(UsernameLabel);
pane.add(username);
pane.add(PasswordLabel);
pane.add(password);
pane.add(Test);
pane.add(Cancel);
//adding the pane
add(pane);
//adding a event listener to my JButton titled Test
Test.addActionListener(this);
//checking if the password variable and name variable are both
//correct by taking the values assigned to each of them later
//on in the code and adding them together and if they add together
//to the correct amount it should display a button, but it doesn't
//which is the problem I am having
if (nathannam + nathannamer == 24) {
ImageIcon superman = new ImageIcon("JButton.png");
JButton supermanny = new JButton(superman);
pane.add(supermanny);
}
//setting visibility to true
setVisible(true);
//end of constructor class
}
//start of class that checks if the username is correct
public void METHODPREFORMED(ActionListener evt) {
Object source = ((EventObject) evt).getSource();
//testing if username is equivalent to my name which is nathan
if (source == Test) {
String get = username.getText().toString();
String notation = "Nathan";
//if it is equivalent a variable will be assigned to nathanam
for (int i = 0; i < get.length(); i++) {
if (get.substring(i) == notation) {
int nathannam = 14;
//if it is not it will assign a wrong variable to nathannam
} else {
int nathannam = 15;
}
}
}
}
//testing if password variable is correct
public void ACTIONPREFORMED(ActionListener evt) {
Object source = ((EventObject) evt).getSource();
//testing if password is correct
if (source == Test) {
String got = password.getText().toString();
String notition = "iamnathan";
//if it is equivalent a variable will be assigned to nathanamer
for (int i = 0; i < got.length(); i++) {
if (got.substring(i) == notition) {
int nathannamer = 10;
//if it is not equivalent nathannamer will be assigned a wrong variable
} else {
int nathannamer = 15;
}
}
}
} //setting the nimbus setlookandfeel that was implemented in java 7
private static void setLookAndFeel() {
try {
UIManager.setLookAndFeel(
"com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel"
);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedLookAndFeelException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//adding the main method
public static void main(String[] args) {
setLookAndFeel();
Main main = new Main();
}
#Override
public void textValueChanged(TextEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void caretPositionChanged(InputMethodEvent event) {
// TODO Auto-generated method stub
}
#Override
public void inputMethodTextChanged(InputMethodEvent event) {
// TODO Auto-generated method stub
}
}//end of program
You never call your test method from your implementation of actionPerformed(). Here's a much simplified version of your program that checks username when you click on TestAccess.
Going forward, see How to Use Password Fields for a working example of using JPasswordField.
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
/**
* #see
*/
public class Test {
private final JTextField username = new JTextField(15);
private final JButton test = new JButton("Test access");
private void display() {
JFrame f = new JFrame("Test");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setLayout(new GridLayout(0, 1));
f.add(username);
test.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("nathan".equalsIgnoreCase(username.getText()));
}
});
f.add(test);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
new Test().display();
});
}
}
I'm trying to get a SwingWorker to work.
I've the following code at the moment:
public class ImageWorker extends SwingWorker<Void, Void> implements KeyListener
{
private JLabel imageLabel;
private ImageIcon basicImage;
private ImageIcon whiteImage;
public static void main(String[] args)
{
new ImageWorker();
}
public ImageWorker()
{
final JFrame frame = new JFrame();
imageLabel = new JLabel();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.getContentPane().add(imageLabel);
frame.setVisible(true);
try
{
basicImage = new ImageIcon(ImageIO.read(new File("src\\img\\basis1.jpg")).getScaledInstance(1024, 768, Image.SCALE_SMOOTH));
whiteImage = new ImageIcon(ImageIO.read(new File("src\\img\\wit.jpg")).getScaledInstance(1024, 768, Image.SCALE_SMOOTH));
}
catch(IOException ex)
{
ex.getMessage();
}
this.execute();
}
#Override
protected Void doInBackground()
{
try
{
while (true)
{
displayImage(basicImage);
Thread.sleep(1000L);
if(isCancelled())
return null;
}
}
catch(InterruptedException e)
{
e.getMessage();
}
return null;
}
private void displayImage(final Icon image)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
imageLabel.setIcon(image);
}
});
}
I was expecting the images to appear in the JLabel, but I only see the JFrame popping up. The files are loaded correctly Ive tested that in another setup.
Any pointers?
Here is an example using a Timer rather than using the SwingWorker which really isn't appropriate to your situation. Note that it's not too different from your existing code.
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.Timer;
public class ImageWorker implements KeyListener
{
private JLabel imageLabel;
private ImageIcon basicImage;
private ImageIcon whiteImage;
private boolean isBasic = true;
private int delay = 1000; //milliseconds
private Timer timer;
public static void main(String[] args)
{
new ImageWorker();
}
public ImageWorker()
{
final JFrame frame = new JFrame();
imageLabel = new JLabel();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.getContentPane().add(imageLabel);
frame.setVisible(true);
try
{
basicImage = new ImageIcon(ImageIO.read(new File("src\\img\\basis1.jpg")).getScaledInstance(1024, 768, Image.SCALE_SMOOTH));
whiteImage = new ImageIcon(ImageIO.read(new File("src\\img\\wit.jpg")).getScaledInstance(1024, 768, Image.SCALE_SMOOTH));
}
catch (IOException ex)
{
ex.getMessage();
ex.printStackTrace();
}
frame.addKeyListener(this);
ActionListener taskPerformer = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
if(isBasic) {
//display basic image
imageLabel.setIcon(basicImage);
}
else {
//display white image
imageLabel.setIcon(whiteImage);
}
//toggle the flag
isBasic = !isBasic;
}
};
//use a timer instead of SwingWorker
timer = new Timer(delay, taskPerformer);
timer.start();
}
#Override
public void keyPressed(KeyEvent e)
{
//key pressed, we want to stop toggling so stop the timer
timer.stop();
//do whatever else you were doing to set the value for isCancelled();
}
#Override
public void keyReleased(KeyEvent e)
{
// TODO Auto-generated method stub
}
#Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
}
}
A SwingWorker is not appropriate for your situation look into a Timer in the swing package. Here is a link to the API: http://download.oracle.com/javase/6/docs/api/javax/swing/Timer.html
You have the timer run and change an image every second since that is what you need.
Also, whenever you have exceptions, print out a stacktrace or the message at least. Otherwise you won't know if an exception occurs and is caught.