This question already has answers here:
How could I add a simple delay in a Java Swing application?
(3 answers)
Closed 6 years ago.
i'm making a poker game for a uni assignment and i was wondering if there is any way to have a method that does as follows ( Note: very roughly written up code )
JTextArea textArea = new JTextArea();
public void printer(String s){
//I want to delay here, for 2 seconds each time i print to the jtextarea
textArea.append(s);
}
public void runGame(){
printer("Dealing cards...");
//I want to delay to add to an effect of the time it takes to actually deal the cards
pokerHand.setVisibility(true);
printer("What you like to do?");
//
//Code here containing running the game
//
printer("Daniel Negreanu folds");
//I want to have a delay here for the time it takes to make a decision.
printer("Phil Hellmuth folds");
Theres many many more instances i want to use this throughout my program, and just wondered if there is any way to do this.
Thanks in advance
EDIT: Not looking to use Thread.sleep() as it doesn't work well with gui.
EDIT2: I want the pokerHand.setVisibility(true), and other methods in my code to execute AFTER the delay, ( using a timer doesn't do this ).
Not looking to use Thread.sleep() as it doesn't work well with gui.
Good, use a Swing Timer instead
I want the pokerHand.setVisibility(true), and other methods in my code to execute AFTER the delay, ( using a timer doesn't do this ).
Yes it does, you're just not using it properly, but since you've not provided any actual code, I can't say "how" you're not using it properly, only from the sounds of it, you are.
Start by taking a look at How to use Swing Timers for more details
The following is very simple example, it uses a Timer to calculate and print the amount of time between the time you clicked the button.
The example updates the UI AFTER the Timer is started, but until the Timer completes, the calculation and result are not generated
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.Duration;
import java.time.LocalTime;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.Timer;
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 {
private JTextArea ta;
private JButton btn;
private Timer timer;
private LocalTime startTime, endTime;
public TestPane() {
setLayout(new BorderLayout());
ta = new JTextArea(10, 20);
add(new JScrollPane(ta));
btn = new JButton("Click");
add(btn, BorderLayout.SOUTH);
timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
endTime = LocalTime.now();
Duration duration = Duration.between(startTime, endTime);
ta.append("Ended # " + endTime + "\n");
ta.append("Took " + (duration.toMillis() / 1000) + " seconds\n");
}
});
timer.setRepeats(false);
ta.setEditable(false);
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
timer.start();
startTime = LocalTime.now();
btn.setEnabled(false);
ta.append("Start # " + startTime + "\n");
}
});
}
}
}
First, your code seems to be imperative ("ask user what to do", "game loop goes here") instead of event-driven ("when this happens, do that"). Read up on event-driven programming, which is used on all GUIs, sooner rather than later.
In event-driven code, there is no big difference between "user clicks a button" and "timeout expires" - both will cause events that your code can react to. So start by rewriting your code so that, once you press a button, the "next thing" happens. Then change it again so that once a timer expires, the same "next thing" happens.
Assuming that you have the following code:
// an ActionListener for both clicks and timer-expired events
private nextThingListener = new ActionListener() {
public void actionPerformed(ActionEvent ae) {
doNextThing();
}
};
// method that does the next thing
public void doNextThing() {
// change the UI in some way
// if using timers, may also start the next timer
}
You can now associate it to a button using:
// create a button and have it do the "next thing" when clicked
JButton jb = new JButton("do next thing");
jb.addActionListener(nextThingListener);
myInterface.add(jb); // <-- display it in the interface somehow
And you can associate it to a timer as:
// launch a timer that will ring the nextThingListener every 2 seconds
new Timer(2000, nextThingListener).start();
If you want to have the timer ring only once, you can use
// launch a timer that will ring the nextThingListener after 2 seconds
Timer t = new Timer(2000, nextThingListener);
t.setRepeats(false);
t.start();
Related
I am trying to create a seven segment display that automatically moves using the timer with the use of the ActionListener and actionPerformed.
I thought that if I use the for, if statement it would automatically loop from 0 to 2 and set the Background color for each segment of the numbers. However, when I display it, it is stuck on just displaying zero and will not count up from there.
Can anyone help me on what I am doing wrong, that makes this stuck on zero?
Here is the programming I have now using JFrame.
import javax.swing.Timer;
public class SevenSegment extends JFrame {
Timer timer = new Timer(100, null);
public SevenSegment() {
timer.start();
timer.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
for (int i = 0; i < 3; i++) {
if(i == 0) {
lblNumberOne.setBackground(Color.red);
lblNumberTwo.setBackground(Color.red);
lblNumberThree.setBackground(Color.red);
lblNumberFour.setBackground(Color.red);
lblNumberFive.setBackground(Color.red);
lblNumberSix.setBackground(Color.red);
}
else if(i == 1) {
lblNumberTwo.setBackground(Color.red);
lblNumberThree.setBackground(Color.red);
}
else if(i == 2) {
lblNumberOne.setBackground(Color.red);
lblNumberTwo.setBackground(Color.red);
}
}
}
});
}
}
Here's about as simple a Swing GUI clock as you can make.
I did this so I could show you a general way to start all of your Swing GUIs. Oracle has a helpful tutorial, Creating a GUI With JFC/Swing, that will show you how to create all kinds of Swing GUIs.
We start all Swing GUIs with a call to the SwingUtilities invokeLater method. This method ensures that all Swing components are created and executed on the Event Dispatch Thread.
We always create a JPanel to put our Swing components on. The only Swing component that we add to a JFrame is a JPanel or a JScrollPane. This allows us to separate the creation of a JFrame from the rest of the view. The JFrame code is nearly identical for all Swing applications. The only difference is the JPanels you add to the JFrame.
The JFrame code must be called in a specific order. This is the order I use for my Swing applications.
The JPanel code is in a separate paragraph for general tidiness. I like to keep things separate so I can focus on one small part of the GUI at a time.
The updateClockLabel method exists because I need to execute the code one time when I'm creating the JPanel, and five times a second thereafter, to actually update the JLabel.
By the way, I didn't write all this code (all 64 lines) in one shot. I wrote a little, tested a lot. My code was not correct the first time I wrote it, and I don't just mean making typos.
Here's the complete runnable code.
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class SimpleClock implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new SimpleClock());
}
private JLabel clockLabel;
#Override
public void run() {
JFrame frame = new JFrame("Clock");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createMainPanel(), BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
Timer timer = new Timer(200, new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
updateClockLabel();
}
});
timer.start();
}
private JPanel createMainPanel() {
JPanel panel = new JPanel(new FlowLayout());
panel.setBorder(BorderFactory.createEmptyBorder(5, 45, 5, 45));
clockLabel = new JLabel(" ");
clockLabel.setFont(panel.getFont().deriveFont(Font.BOLD, 72f));
updateClockLabel();
panel.add(clockLabel);
return panel;
}
public void updateClockLabel() {
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("H:mm:ss a");
String timeDisplay = LocalTime.now().format(formatter);
clockLabel.setText(timeDisplay);
}
}
This question already has answers here:
Updating GUI from a runnable
(3 answers)
Closed 5 years ago.
I have a GUI that I have developed that has a couple of buttons and a JTextArea for output. I have some code below that executes a function and updates the TextArea, however before the function is executed I would like the TextArea to be updated with the string "Processing...", just to give the user some kind of idea that the application is working as the function takes a while to execute.
At the moment this code doesn't update the GUI element and I understand why. The GUI doesn't get a chance to repaint in between the two commands that change the TextArea, so the "processing..." string is never displayed. How do I change the code so that the GUI element updates before the Main.featureAnalysisTop() function executes?
if(e.getActionCommand().equals("Extract Features"))
{
featuresTextArea.setText("Processing...");
int nFeatures = nFeatureSlider.getValue();
Main.featureAnalysisTop(nFeatures);
featuresTextArea.setText("");
ArrayList<String> featureList = Main.getFeatureList();
for(String str : featureList)
{
featuresTextArea.append(str + "\n");
}
The GUI is executed in my main method using the following code.
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
gui = new GUI2();
gui.setLocationRelativeTo(null);
gui.frmNeuralNetwork.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
Updating GUI on separate thread while other method is executing
That's a job for the Swing Woker class, which allows you to create a separate thread that runs in the background and lets you update your GUI accordingly.
For example, I made a simple example that accomplishes what you're trying to do.
First we create the GUI and add an ActionListener to our JButton where it starts our Swing Worker after updating the JTextArea's text to processing... as you were trying to do it and after 5 seconds (which simulates your long running task) it updates to I'm done!.
You can try it and change the code accordingly.
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.util.concurrent.ExecutionException;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.SwingWorker;
public class TextAreaUpdater {
private JFrame frame;
private JTextArea area;
private JButton button;
private SwingWorker<String, String> worker;
public static void main(String[] args) {
SwingUtilities.invokeLater(new TextAreaUpdater()::createAndShowGui);
}
private void createAndShowGui() {
frame = new JFrame(getClass().getSimpleName());
area = new JTextArea(10, 30);
button = new JButton("Update!");
button.addActionListener(listener);
worker = new SwingWorker<String, String>() {
#Override
protected String doInBackground() throws Exception {
try {
Thread.sleep(5000); //Simulates long running task
} catch (InterruptedException e) {
e.printStackTrace();
}
return "I'm done!"; //Returns the text to be set on the JTextArea
}
#Override
protected void done() {
super.done();
try {
area.setText(get()); //Set the textArea the text given from the long running task
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
};
frame.add(area, BorderLayout.CENTER);
frame.add(button, BorderLayout.SOUTH);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
private ActionListener listener = (e -> {
area.setText("Processing...");
worker.execute(); //Initializes long running task
});
}
References:
Swing Worker Example
How do I use SwingWorker in Java?
Here's another example that uses SwingWorker: update jlabel text after opening jdialog
Hope it helps
I've recently made a small puzzle game that deals with clicking certain areas. I also made a solver which activates the necessary areas to win. The problem that I am facing is that I would like to pause each time it activates an area to create a sort of "solving animation". My problem is represented here
package experiment;
import java.awt.Dimension;
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 ExperimentHere extends JFrame implements ActionListener
{
private static final long serialVersionUID = 1L;
private JButton changeLabelButton;
private JPanel mainPanel;
private JLabel labelToChange;
public ExperimentHere() {
changeLabelButton = new JButton("Set the label");
changeLabelButton.addActionListener(this);
mainPanel = new JPanel();
labelToChange = new JLabel();
labelToChange.setText("This needs to be changed");
mainPanel.add(labelToChange);
mainPanel.add(changeLabelButton);
this.add(mainPanel);
setTitle("Timer Program");
setContentPane(mainPanel);
setPreferredSize(new Dimension(1000, 1000));
pack();
}
public void actionPerformed(ActionEvent e) {
if (e.getSource().equals(changeLabelButton)){
changeLabel();
}
}
public void changeLabel(){
for (int i = 0; i<5; i++){
labelToChange.setText(""+i);
// Pause for 200ms here
}
}
public static void main(String[] args){
ExperimentHere test = new ExperimentHere();
test.setVisible(true);
}
}
I have tried using Timers, but I'm not sure how to format it properly so that it only pauses each time the loop inside of changeLabel() is incremented, because the second paramter in Timer() asks for an ActionListener.
I've also tried using Thread.sleep() but it just freezes my program and then instantly solves it.
Ideally the changeLabel method would increment by 1, set the label to the new String, wait for 200ms, and then increment again.
I have tried using Timers, but I'm not sure how to format it properly so that it only pauses each time the loop inside of changeLabel() is incremented
When you use a Timer you don't use a loop. The point of a Timer is that you start the Timer and it keeps executing until you stop the Timer.
You also don't make methods, you make an Action to invoke whenever the Timer fires.
So you need an instance variable in your class that keeps track of the number of times the Timer has fired (lets call it "timerCounter"). Then you need to create an Action to invoke every time the Timer is fired.
So you create a couple of instance variables:
int timerCounter = 0;
Action action;
Then in the constructor of your class you create an Action something like:
action = new AbstractAction()
{
#Override
public void actionPerformed(ActionEvent e)
{
labelToChange.setText("" + timerCounter);
timerCounter++;
if (timerCounter > 5)
{
Timer timer = (Timer)e.getSource();
timer.stop();
}
}
}
So now in the ActionListenerof your button you can do something like:
timerCounter = 0;
Timer timer = new Timer(200, action);
timer.start();
Is there a way to send the java frame in front of every other opened program. I know you can use
JFrame.setAlwaysOnTop(true);
but that just keeps it in front allways. I want it to only happen when a certain function is called. For instance, When I press a button on a frame, it will wait using Thread.sleep(10000) for ten seconds, but the I want it to just the frame to the front in case you clicked out of the window for a second. Any suggestions?
Take a look at Window#toFront
You may also want to take a look at
WindowListener
Swing Timer
Be careful of using Thread.sleep in a GUI environment, if used incorrectly, this will cause you window to stop updating (painting)
This is surprisingly fiddly.
The exact behavior might also depend on the operating system. But at least on Windows, a call to frame.toFront() will not necessarily bring the window to the front. Instead, it will cause the corresponding entry in the task bar to blink for a few seconds. I tried something like
f.setAlwaysOnTop(true);
f.setAlwaysOnTop(false);
which basically works, but after the window was brought to the front, it is not "active", and none of my attempts to make it active worked (e.g. requesting the focus or so).
The only solution that I found now to (reliably) work (on Windows, at least) was
if (!f.isActive())
{
f.setState(JFrame.ICONIFIED);
f.setState(JFrame.NORMAL);
}
But wonder wheter there is a more elegant solution.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class FrameToTopTest
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
final JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Bring me to top after 3 seconds");
button.addActionListener(new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
triggerBringToFront(f, 3000);
}
});
f.getContentPane().add(button);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static void triggerBringToFront(final JFrame f, final int delayMS)
{
Timer timer = new Timer(delayMS, new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
// This will only cause the task bar entry
// for this frame to blink
//f.toFront();
// This will bring the window to the front,
// but not make it the "active" one
//f.setAlwaysOnTop(true);
//f.setAlwaysOnTop(false);
if (!f.isActive())
{
f.setState(JFrame.ICONIFIED);
f.setState(JFrame.NORMAL);
}
}
});
timer.setRepeats(false);
timer.start();
}
}
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What I want to do in my java program is, that when I press the button it displays text in textfield in intervals of time.
i.e I press the button then a jFrame pops up and there is a label which shows text like:
1st second:"1st"
then a time lag of say 1 sec
then 2nd thing: "2nd"
I am a newbie and I tried to Google this problem but I couldn't find a solution even after 3-4 hours
I tried a lot of things: sleep, try n catch...
Please write the answer very simplified.
Here is my code:
In the following code, when the button is pressed, the jFrame comes but has a white screen in it and when the sum ends, its screen turns grey and it shows the answer....
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
See.setVisible(true);//See is the JFrame
t007.setVisible(true);//Label in See
l2.setVisible(true);//TextField in See
int ran, g, d, col, ran2;
double y = 1000 * (Double.parseDouble(t2.getText()));
int x = (int) y;
d = 0;
double c = Math.pow(10, Integer.parseInt(t1.getText()));
col = Integer.parseInt(t3.getText());
for (g = 0; g < col;) {
ran = (int) (Math.random() * (c)); // Random Number Creation Starts
if (ran > (c / 10)) {
g = g + 1;
ran2 = ((int) (Math.random() * 10)) % 2;
if (ran2 == 1) {
ran = ran * (-1);
}
d = d + ran;
if (d < 0) {
ran = ran * (-1);
d = d + (2 * ran);
}
l2.setVisible(true);
t007.setText("" + ran);
System.out.println("" + ran);
jButton6.doClick();
//Pausing (Sleep)
try {
Thread.sleep(x);
} catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
l2.setText("" + d);
}
Swing is a single threaded framework, that is, all interactions and modifications to the UI are expected to occur within the context of the Event Dispatching Thread.
The EDT is responsible for, amongst other things, processing repaint requests.
Anything that stops the EDT from running (like Thread.sleep and looping for a long time) will prevent it from processing the events, virtually "hanging" your application until it becomes unblocked...
Now, I tried to decipher what you program was trying to do...but failed, so instead...I made a pretty counter...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TickOver {
public static void main(String[] args) {
new TickOver();
}
public TickOver() {
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 JTextField field;
private JButton button;
private int tick;
private Timer timer;
public TestPane() {
field = new JTextField(10);
field.setEditable(false);
button = new JButton("Start");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
button.setEnabled(false);
tick = 0;
timer.start();
}
});
timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
field.setText(Integer.toString(++tick));
if (tick > 4) {
timer.stop();
button.setEnabled(true);
}
}
});
timer.setInitialDelay(0);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
add(field, gbc);
add(button, gbc);
}
}
}
Take a close look at Concurrency in Swing for more details...
You should never sleep in UI thread, as it make the UI lag. As if the process takes time to complete the UI will get stuck and user experience will get hurt.
Use other mechanisms such as a Timer or SwingWorker
Concurrency in Swing
It's very bad practice to sleep the user interface thread. (As this will cause the application to become unresponsive.) You ought to put all this code inside the Run() method of a Runnable instance:
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
// Your code here.
}
});
The problem is that you run your long running loop on the event dispatch thread. But this is the thread that must dispatch all events of the application like mouse or keyboard events but also repaint events that causes your user interface to get repainted every time it gets 'dirty'. That means, while your for-loop is running, the user interface is not repainted nor are any other events processed. Your UI freezes!
Your jButton5ActionPerformed method should return as soon as possible so that the event dispatch thread can process other events. Your long running operation should be run by a separate thread in the background.
A good starting point is the following tutorial about concurrency in Swing:
http://docs.oracle.com/javase/tutorial/uiswing/concurrency/
Maybe you can use the SwingWorker class to perform your background work:
http://docs.oracle.com/javase/6/docs/api/javax/swing/SwingWorker.html