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I am a beginner and I am trying to make a card flip game in netbeans

On clicking an image I want another image to be displayed pause for one second and the original image to be restored and displayed againdisplayed again When I try to do it it action handler such as code given below it sets the image after sleep .I want the image to be displayed pause and the original to be displayed again how can I achieve that
private void jButton16ActionPerformed(java.awt.event.ActionEvent evt) {
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\O.png"));
try { //sleep 1 seconds
Thread.sleep(1000);
}
catch (InterruptedException e)
{
}
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\118px-AMIGO.jpg")); }

Swing is single threaded, you should never perform long running or blocking operations within the context of the Event Dispatching Thread
Swing is NOT thread safe, this means you should never update the UI (and anything the UI needs) outside of the context of the EDT
The simplest solution to your problem is to use a Swing Timer
private void jButton16ActionPerformed(java.awt.event.ActionEvent evt) {
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\O.png"));
Timer timer = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\118px-AMIGO.jpg"));
}
});
timer.setRepeats(false);
timer.start();
}
See Concurrency in Swing and How to use Swing Timers for more details

You should never invoke Thread.sleep() inside Event Dispatch Thread
because Thread.sleep() will block Event Dispatch Thread and your UI will be Freeze , instead you could use a Timer to achieve your goal
Refer below code,
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\O.png"));
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
jButton16.setIcon(new javax.swing.ImageIcon("C:\\Users\\x\\Documents\\118px-AMIGO.jpg"));
}
});
timer.setRepeats(false);
timer.start();

Changing a label during ActionEvent

I am trying to enable/disable a label when a button is pressed and i want to do this during the event and not after it. As you can see below, i try to enable/disable the two labels: lblKeyboard and lblGamepad.
They end up running after the "RemoteControl.run();" is executed but i want it to happen before that. Any way i can do that?
Thank you!
JButton btnGamepad = new JButton("Gamepad");
btnGamepad.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(cont_state == 0){
if(RemoteControl.findGamePad() == true){
cont_state = 1;
game_status = "on";
}
else{
game_status = "off";
key_status = "on";
JOptionPane.showMessageDialog(null, "Controller not found!");
cont_state = 0;
}
}
if(cont_state == 1){
System.out.println("CONNECTED GAMEPAD!");
lblKeyboard.disable();
lblGamepad.enable();
frame.repaint();
RemoteControl.run();
cont_state = 0;
}
}
});

ActionEvents are run on the EDT which is also responsible for painting. Once you change the labels state, Swing issues a request for repaiting the Label. The thing is that this request is posted on a queue and will be executed once the EDT is free and, as you can see, the EDT is busy running your code so no repainting for you! Depending on the nature of your code, you should consider using a SwingWorker or simply moving RemoteControl.run() to another Thread as in
new Thread(new Runnable() {
#override
public void run() {
RemoteControl.run();
}
}).start();

Code in an event listener executes on the Event Dispatch Thread (EDT) and the GUI can't repaint itself until all the code has finished executing. Read the section from the Swing tutorial on Concurrency for more information on the EDT.
Try wrapping your RemoteControl.run() code in a SwingUtilities.invokeLater(...). This will place the code at the end of the EDT, which might give Swing a changes to repaint the state of the two labels.
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
RemoteControl.run()
}
});
This assumes your code updates the GUI. If not, then just use a separate Thread.

Delay routine in Swing on button click which should not stall the application

I am trying to do the following: click a button, button disappears for 2 seconds, text appears for 2 seconds and after those 2 seconds the visibility is reversed. So far I have done this:
btnScan.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
txtScanning.setVisible(true);
btnScan.setVisible(false);
try {
Thread.sleep(2000); //1000 milliseconds is one second.
} catch(InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
btnScan.setVisible(true);
}
});
and the result is that as soon as I click the btnScan, the whole program freezes for 2 seconds before doing anything. How do I add the delay at the correct order?

You should not call sleep method in your code that dispatches the event. All the work related UI is handled by EDT(Event Dispatch Thread) and a sleep method will cause it to freeze and hence your Swing application will freeze.
To overcome it you should use a Timer. Run the timer and execute the UI manipulation using SwingUtilities.invokeLater so that it is handled by EDT.
import java.util.Timer;
// make it a member variable
Timer timer = new Timer();
........
public void actionPerformed(java.awt.event.ActionEvent evt) {
button.setVisible(false);
timer.schedule(new TimerTask() {
#Override
public void run() {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
button.setVisible(true);
}
});
}
}, 2000);
}

Currently in your code, you are causing the EDT (event dispatcher thread) to pause with the invocation of Thread.sleep
Performing any long running tasks in the EDT will cause your UI to freeze.
To achieve what you desire, use a SwingWorker thread to perform your actions
This might help: http://docs.oracle.com/javase/tutorial/uiswing/concurrency/worker.html

Swing is a single threaded environment, anything that blocks this thread will prevent it from processing new events, including repaint requests.
Swing is also not thread safe, meaning img you should never create or update the UI from outside the context of the EDT.
In this case you can use a Swing Timer to trigger a callback to occur at some time in the future which (the notification) will be executed within the context of the EDT, making it safe to update the UI with
Take a look at Concurrency in Swing and How to us Swing Timers for more details

Making use of Swing timer, you can do something like this:
btnScan.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
txtScanning.setVisible(true);
btnScan.setVisible(false);
Timer timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent acv) {
btnScan.setVisible(true);
txtScanning.setVisible(false);
}
});
// setRepeats(false) to make the timer stop after sending the first event
timer.setRepeats(false);
timer.start();
}
});

Updating buttons inside or outside of SwingWorker?

I want to disable a number of buttons/menu items of my GUI while a SwingWorker thread is running. The thread is started when a button is clicked.
It looks like the while loop in my code causes the CPU load to go up significantly. Did I get something wrong about how to determine if a SwingWorker thread is still running?
The CPU load's definitely lower when I update the buttons/menu items inside the SwingWorker thread. However, I felt like that shouldn't be the SwingWorker thread's job. Should it?
JButton button = new JButton("Start");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
Thread t = new Thread(new Runnable() {
#Override
public void run() {
menu.setEnabled(false);
MySwingWorker worker = new MySwingWorker();
worker.execute();
while (true) {
if (worker.isCancelled() || worker.isDone()) {
menu.setEnabled(true);
break;
}
}
}
});
t.start();
}
});

Swing GUI objects should be constructed and manipulated only on the event dispatch thread (EDT). Doing so from t is incorrect. As suggested in examples cited here, condition your GIU elements on the EDT before starting the worker, and update the GUI in process() or done().

On click, Text of jLabel appears but not the Icon Image?

When I click Print Button it should show a Gif Animation followed by the text "Working..."
but here only the text "Working..." appears , not the animation.
Here's the Code:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
jLabel1.setVisible(true);
/* This portion is Time Consuming so I want to display a Loading gif animation. */
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
empPrint=new HashMap();
if(!empPrint.isEmpty())
empPrint.clear();
if(jRadioButton1.isSelected())
empPrint.put("PNO",parent.emp.getPAN());
else
empPrint.put("PNO",records.get(jComboBox1.getSelectedItem()));
REPORT="Report.jrxml";
try {
JASP_REP =JasperCompileManager.compileReport(REPORT);
JASP_PRINT=JasperFillManager.fillReport(JASP_REP,empPrint,parent.di.con);
JASP_VIEW=new JasperViewer(JASP_PRINT,false);
JASP_VIEW.setVisible(true);
JASP_VIEW.toFront();
}
catch (JRException excp) {
}
setVisible(false);
}
});
}

You should use a SwingWorker for time consuming tasks. Using invokeLater() just pushes it to the event queue, and it gets run in the EDT, blocking it.
Drawing in swing is done in the event dispatch thread, but since the EDT is busy running your printing task, swing has no chance to process repaint requests.
// Note the upped case "Void"s
SwingWorker worker = new SwingWorker<Void, Void>() {
#Override
public Void doInBackground() {
// Do the printing task here
return null;
}
#Override
public void done() {
// Update the UI to show the task is completed
}
}.execute();

The SwingUtilities.invokeLater() method will not help you in this case. The Runnable you pass still gets executed on the Event Dispatch Thread (EDT, the thread responsible for drawing the UI and responding to clicks etc.).
You could look at SwingWorkers, but you could just as well use a simple ExecutorService and pass the Runnable to there. The Executor framework - which was added in Java 5 or 6 - offers relatively simple to use tools to have stuff run in the background without having to worry about your own threads. I recommend going with something like this (pseudo code):
private ExecutorService executor = Executors.newFixedExecutorService()
....
public void buttonPressed() {
label.setVisible(true);
...
executor.submit(new Runnable() {
// create the report etc.
// DO NOT ACCESS ANY UI COMPONENTS FROM HERE ANYMORE!
// ...
SwingUtilities.invokeLater(new Runnable() {
// update the UI in here
label.setVisible(false);
});
});
}
As you can see, SwingUtilities.invokeLater is used here, too. However, it is called from a background thread to make sure your UI code gets executed on the EDT instead of on the background thread. That is what it is designed for, because UI components must never be accessed (not even read from!) from a background thread. That way you have a convenient mechanism to update you label nevertheless. You could also use it to update some progress bar etc.