how to start a function after stop typing in a JTextField. Not for every key release. If two key release time difference is greater than 1 second then it will run this function. Otherwise wait for 1 second.
Use a Swing Timer and a DocumentListener, each time the Document is updated, reset the Timer
Have a look at How to use Swing Timers and Listening for Changes on a Document for more details
As a, simple, example...
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
JTextField field = new JTextField(20);
JLabel label = new JLabel("Waiting");
DeferredDocumentListener listener = new DeferredDocumentListener(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// Execute your required functionality here...
label.setText(label.getText() + ".");
}
}, true);
field.getDocument().addDocumentListener(listener);
field.addFocusListener(new FocusListener() {
#Override
public void focusGained(FocusEvent e) {
listener.start();
}
#Override
public void focusLost(FocusEvent e) {
listener.stop();
}
});
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(field, gbc);
add(label, gbc);
}
}
public class DeferredDocumentListener implements DocumentListener {
private final Timer timer;
public DeferredDocumentListener(int timeOut, ActionListener listener, boolean repeats) {
timer = new Timer(timeOut, listener);
timer.setRepeats(repeats);
}
public void start() {
timer.start();
}
public void stop() {
timer.stop();
}
#Override
public void insertUpdate(DocumentEvent e) {
timer.restart();
}
#Override
public void removeUpdate(DocumentEvent e) {
timer.restart();
}
#Override
public void changedUpdate(DocumentEvent e) {
timer.restart();
}
}
}
If you don't mind using two libraries, this is very easy to solve with RxSwing and RxJava:
EventQueue.invokeLater(() -> {
try {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BorderLayout());
JTextField textField = new JTextField(30);
frame.getContentPane().add(textField, BorderLayout.NORTH);
// HERE
SwingObservable.fromDocumentEvents(textField.getDocument())
.debounce(1, TimeUnit.SECONDS)
.map(documentEvent -> textField.getText())
.subscribe(System.out::println);
frame.setVisible(true);
frame.pack();
} catch (final Exception e) {
e.printStackTrace();
}
});
Related
I have frame with JFormattedTextField(s). My simplified code can look like:
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(100,100);
frame.setLayout(new GridLayout(2,2));
JFormattedTextField field1 = new JFormattedTextField(NumberFormat.getInstance());
field1.setValue(0.4);
frame.add(new JLabel("value A"));
frame.add(field1);
JFormattedTextField field2 = new JFormattedTextField(NumberFormat.getInstance());
field2.setValue(0.8);
frame.add(new JLabel("value B"));
frame.add(field2);
frame.setVisible(true);
which generates:
Goal
When I click/focus on any of JFormattedTextField I would like it to automatically place caret at the end
Problem
I tried using following solutions before calling frame.setVisible(true); but none of them seems to work
from How to set AUTO-SCROLLING of JTextArea in Java GUI?
field1.setCaretPosition(field1.getDocument().getLength());
from https://tips4java.wordpress.com/2008/10/22/text-area-scrolling/ ((DefaultCaret)field2.getCaret()).setUpdatePolicy(DefaultCaret.ALWAYS_UPDATE);
Works without issue for me....
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
JTextField textField = new JTextField("This is a test");
add(textField, gbc);
JButton button = new JButton("This is a button");
add(button, gbc);
button.setFocusable(false);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (textField.getCaretPosition() != 0) {
textField.setCaretPosition(0);
} else {
textField.setCaretPosition(textField.getText().length());
}
textField.requestFocusInWindow();
}
});
}
}
}
Provide a runnable example which doesn't work if you still have issues
Update with JFormattedTextField....
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
JFormattedTextField textField = new JFormattedTextField("This is a test");
textField.setValue(0.8d);
add(textField, gbc);
JButton button = new JButton("This is a button");
add(button, gbc);
button.setFocusable(false);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (textField.getCaretPosition() != 0) {
textField.setCaretPosition(0);
} else {
textField.setCaretPosition(textField.getText().length());
}
textField.requestFocusInWindow();
}
});
}
}
}
Updated with "set at beginning"
Okay, I just want to point out that I have personally dislike of JFormattedTextField, it does a lot of "things" at times which don't always make sense.
An "old" trick I've used, when implementing a "auto select all on focus gain", is to offload the request to the end of the Event Dispatching Thread, this places the request AFTER all the "funky stuff" that the JFormattedTextField does when the field becomes focused...
JFormattedTextField textField = new JFormattedTextField("This is a test");
textField.setValue(0.8d);
add(textField, gbc);
textField.addFocusListener(new FocusAdapter() {
#Override
public void focusGained(FocusEvent arg0) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
textField.setCaretPosition(textField.getText().length());
}
});
}
});
Yes, I'm serious ...
I need the frame to update and display how many times the Button has been pressed (the button's text to update)
If I can use actionPreformed() to be locked on to specific events (Button press, or the Menu item being pressed), then I think that should help...
Problems:
When Button is pressed it creates more frames
The existing Frame(s) do not update (I only want there to be one frame anyway)
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class ButtonFrame implements InternalFrameListener, ActionListener
{
JFrame myFrame = null;
private int clicked;
final String F=("Clicked: "+clicked+" Times!");
public static void main(String[] a)
{
(new ButtonFrame()).test();
}
private void test()
{
myFrame = new JFrame("Internal Frame with a Button");
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myFrame.setSize(400,400);
myFrame.setContentPane(new JDesktopPane());
JMenuBar Start_Bar = new JMenuBar();
JMenu Start_Menu = new JMenu("Frame");
JMenuItem Start_Item = new JMenuItem("Start");
Start_Item.addActionListener(this);
Start_Menu.add(Start_Item);
Start_Bar.add(Start_Menu);
myFrame.setJMenuBar(Start_Bar);
myFrame.setVisible(true);
}
public void actionPerformed(ActionEvent Start_Item)
{
JInternalFrame f = new JInternalFrame("Button Frame");
f.setResizable(true);
f.setClosable(false);
f.setMaximizable(true);
f.setIconifiable(true);
f.setSize(200,200);
f.setLocation(100,100);
f.addInternalFrameListener(this);
f.setVisible(true);
Button objButton1;
objButton1=new Button ("Clicked: "+clicked+" Times!");
objButton1.setBounds(20,90,40,50);
f.add(objButton1);
objButton1.addActionListener(this);
myFrame.getContentPane().add(f);
}
public void actionPreformed(ActionEvent objButton1)
{
clicked++;
}
public void internalFrameActivated(InternalFrameEvent e)
{
System.out.println("Internal Button Ready");
}
public void internalFrameClosed(InternalFrameEvent e)
{
System.out.println("Internal frame closed");
}
public void internalFrameClosing(InternalFrameEvent e)
{
System.out.println("Internal frame closing");
}
public void internalFrameDeactivated(InternalFrameEvent e)
{
System.out.println("Internal frame deactivated");
}
public void internalFrameDeiconified(InternalFrameEvent e)
{
System.out.println("Internal frame deiconified");
}
public void internalFrameIconified(InternalFrameEvent e)
{
System.out.println("Internal frame iconified");
}
public void internalFrameOpened(InternalFrameEvent e)
{
System.out.println("Internal frame opened");
}
}
Based on your description, you solution is screaming isolation and separation of code responsibility, the code responsible for managing the button should be separated from the code managing the frame and desktop pane
This way, you can use separate ActionListeners as well as isolate the functionality to a single instance of the button class
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JDesktopPane dp = new JDesktopPane();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JMenuBar Start_Bar = new JMenuBar();
JMenu Start_Menu = new JMenu("Frame");
JMenuItem Start_Item = new JMenuItem("Start");
Start_Item.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JInternalFrame f = new JInternalFrame("Button", true, true, true, true);
f.setSize(200, 200);
f.setLocation(100, 100);
f.add(new ButtonPane());
f.setVisible(true);
dp.add(f);
}
});
Start_Menu.add(Start_Item);
Start_Bar.add(Start_Menu);
frame.setJMenuBar(Start_Bar);
frame.add(dp);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ButtonPane extends JPanel {
private JButton button;
private int count = 0;
public ButtonPane() {
setLayout(new GridBagLayout());
button = new JButton("0");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
count++;
button.setText(Integer.toString(count));
}
});
add(button);
}
}
}
Is there a listener I can add to a Swing combobox that will trigger when the combobox is enabled or disabled?
I have tried different listeners like componentlistener, itemlistener, propertychangelistener but in vain. I'm using JDK 1.6.
PropertyChangeListener seems to work just fine for me...
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
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.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class EnabledTest {
public static void main(String[] args) {
new EnabledTest();
}
public EnabledTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
final JComboBox cb = new JComboBox(new Object[]{"One", "Two", "Three"});
add(cb, gbc);
cb.addPropertyChangeListener("enabled", new PropertyChangeListener() {
#Override
public void propertyChange(PropertyChangeEvent evt) {
System.out.println("State changed for " + evt.getPropertyName() + " to " + evt.getNewValue());
}
});
JButton btn = new JButton("Switch");
add(btn, gbc);
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cb.setEnabled(!cb.isEnabled());
}
});
}
}
}
I am trying to make a game like simon: http://www.freegames.ws/games/kidsgames/simon/simon.htm#
I am making a smaller scale with only 2 buttons. I want the color to switch between 2 buttons, button1 and button2. This is in a thread because I need buttons to be clicked while this is happening. When I open the program the button color stays as-is.
Thanks for help in advance!
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import javax.swing.*;
public class TestFrame extends JFrame{
public JButton button1;
public JButton button2;
boolean isTrue = true;
boolean switchColor = true;
TestFrame(){
super("Simon");
initialize();
this.setSize(200, 400);
this.setVisible(true);
}
private void initialize() {
this.setLayout(new BorderLayout());
button1 = new JButton();
button1.setBackground(Color.green);
button1.setSize(200,200);
button2 = new JButton();
button2.setSize(200, 200);
button2.setBackground(Color.blue);
this.add(button1, BorderLayout.NORTH);
this.add(button2, BorderLayout.SOUTH);
Thread t = new Thread(r1);
t.start();
}
Runnable r1 = new Runnable() {
public void run() {
while(isTrue){
if(switchColor = true){
button1.setBackground(Color.blue);
button2.setBackground(Color.green);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
refresh();
switchColor = false;
} else {
button1.setBackground(Color.green);
button2.setBackground(Color.blue);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
refresh();
switchColor = true;
}
}
}
};
public void refresh(){
this.invalidate();
this.validate();
this.repaint();
}
}
A number of issues stand out (shazin has addressed one), the other that scares me is you are violating the single thread requirements of Swing. All changes to the UI must be made from within the context of the Event Dispatching Thread.
Instead of using a Thread, you should be using a javax.swing.Timer. This will save you the need to have to resync your updates back to the EDT.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class FlashyButtons {
public static void main(String[] args) {
new FlashyButtons();
}
public FlashyButtons() {
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 JButton btn1;
private JButton btn2;
private int count = 0;
public TestPane() {
setLayout(new GridBagLayout());
btn1 = new FlashButton();
btn2 = new FlashButton();
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(btn1, gbc);
add(btn2, gbc);
btn1.setBackground(Color.GREEN);
btn2.setBackground(Color.BLUE);
Timer timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
count++;
if (count % 2 == 0) {
btn1.setBackground(Color.BLUE);
btn2.setBackground(Color.GREEN);
} else {
btn1.setBackground(Color.GREEN);
btn2.setBackground(Color.BLUE);
}
}
});
timer.start();
}
}
public class FlashButton extends JButton {
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}
Take a look at Concurrency in Swing for more details
if(switchColor = true){
button1.setBackground(Color.blue);
button2.setBackground(Color.green);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
refresh();
switchColor = false;
} else {
button1.setBackground(Color.green);
button2.setBackground(Color.blue);
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
refresh();
switchColor = true;
}
}
In the above code change the following to
if(switchColor = true){
to
if(switchColor == true){
or just
if(switchColor){
And it is best to have your Runnable anonymous class inside
SwingUtilities.invokeLater(new Runnable() {
public void run() {
}
});
than using a new Thread object to create and start the thread as it will be changing the Swing UI properties.
I am trying to implement a swing frame. In this, I want to display a processing status in a textPanel using a different thread while performing the needed task. I tried the following code. Of course there is something wrong with the logic. Please provide me with the proper approach
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class SampleSwing {
private JFrame frame;
public static JTextField textField;
public static boolean processing=false;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
SampleSwing window = new SampleSwing();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public SampleSwing() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
textField = new JTextField();
textField.setBounds(0, 31, 434, 20);
frame.getContentPane().add(textField);
textField.setColumns(10);
JButton btnNewButton = new JButton("New button");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
processing=true;
Processingstatus ps=new Processingstatus();
ps.start();
/*perform the actual task*/
processing=false;
}
});
btnNewButton.setBounds(174, 74, 89, 23);
frame.getContentPane().add(btnNewButton);
}
}
class Processingstatus extends Thread{
public void run() {
try {
while(SampleSwing.processing) {
SampleSwing.textField.setText("Processing");
Thread.sleep(1000);
SampleSwing.textField.setText("Processing..");
Thread.sleep(1000);
SampleSwing.textField.setText("Processing...");
Thread.sleep(1000);
}
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
First I thought, "you should be using a SwingWorker, as it has methods to handle progress and EDT updates..."
But when I looked closer, you don't actually really care about the process itself, you just want some where to show that a process is running...They are two separate entities, that are only related because one (the UI updates) will run so long as the other is running.
So, instead, I used a javax.swing.Timer. This allows me to schedule an event to occur every n milliseconds and have that triggered in the EDT, nice and clean...
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.SwingWorker;
import javax.swing.Timer;
public class SampleSwing {
private JFrame frame;
public static JTextField textField;
public static boolean processing = false;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
SampleSwing window = new SampleSwing();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public SampleSwing() {
initialize();
}
private Timer processTimer;
private void initialize() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
textField = new JTextField(25);
frame.add(textField, gbc);
processTimer = new Timer(500, new ActionListener() {
private StringBuilder dots = new StringBuilder(3);
#Override
public void actionPerformed(ActionEvent e) {
dots.append(".");
if (dots.length() > 3) {
dots.delete(0, dots.length());
}
textField.setText("Processing" + dots.toString());
}
});
JButton btnNewButton = new JButton("New button");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
if (!processing) {
processing = true;
processTimer.start();
} else {
processTimer.stop();
processing = false;
textField.setText(null);
}
}
});
frame.add(btnNewButton, gbc);
frame.pack();
frame.setLocationRelativeTo(null);
}
}
ps For the reason why your original code didn't work, see my comment in the above comments section ;)