private void runInBackground() {
new Thread(new Runnable() {
#Override
public void run() {
while (running) {
try {
checkPixel();
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
public void stop() {
this.running = false;
}
public void start() {
this.running = true;
}
So I have some code someone provided me to monitor the change in color in the middle of the screen. I want to essentially turn on/off checkPixel() after I press something like F9 but how can I do this without a GUI because I can't seem to find anything that allows this. I believe KeyListeners only work with GUIs?
EDIT: Ok so instead while I'm checking for pixel changes in the thread. Once a pixel change has been detected I want to cause create a "left click action" in checkPixel() then turn off the thread. Any help with this?
I guess you want functionality provided by JNativeHook library.
The library allows for grabbing a key from the backgrond.
Related
I know time and time again people have asked how to start a thread after it's been stopped and everyone says you can't. This isn't a duplicate to that because I've found no solution for the problem.
private void runInBackground() {
new Thread(new Runnable() {
#Override
public void run() {
while (running) {
try {
checkPixel();
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
Thread.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
#Override
public void nativeKeyPressed(NativeKeyEvent e) {
// TODO Auto-generated method stub
System.out.println("Key Pressed: " + NativeKeyEvent.getKeyText(e.getKeyCode()));
if(NativeKeyEvent.getKeyText(e.getKeyCode()).equals("F9")){
stop();
}
else if(NativeKeyEvent.getKeyText(e.getKeyCode()).equals("F10")){
}
So in my code I'm listening for global key events using JNativeHook. I can successfully stop the checkPixels() using the F9 key but I'm not understanding what I should do using F10 when I wanna start up checkPixel() again.
checkPixel() basically checks for a change in pixel color
ANSWERED Added an if statement for my state variable running and keep the while loop true allows me to turn on/off the method while keeping the thread open. Thank you Jaboyc
private void runInBackground() {
new Thread(new Runnable() {
#Override
public void run() {
while (true) {
if(running){
try {
checkPixel();
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
Thread.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}).start();
}
Would this work
while (true) {
if (running) {
doStuff();
}
}
in the run method?
Can't figure this one out. Using worker or invokeLater, the UI still freeze. After each file is downloaded, I want a JList to be updated. But the JList will only update after the tread returns.
Here is the code:
public class MyUi extends javax.swing.JFrame{
...
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt){
SwingUtilities.invokeLater(new Runnable() {
//To get out of the event tread
public void run() {
dl();
}
});
}
private void dl(){
...
//ini and run the download class
Download myDownload = new Download();
myDownload.doDownload(myDlList);
}
public void updateJlist(String myString){
myModel.addElement(myString);
jList1.repaint();
}
}
public class Download{
...
public void doDownload(String[] fileName){
for(int i=0; i<fileName.length; i++){
...//download action...
//for my jList1 to be updated after each file.
MyUi.updateJlist(fileName[i]);
}
}
}
Any example would help.
invokeLater does exactly the opposite of what you expect it to do - it runs operations on the EDT, which explains the behaviour.
Download the file on a background thread and wrap just updateJlist() in a Runnable.
SwingWorker would be more reliable.
Addendum: As #mre notes, SwingWorker also makes it easy to report interim results, as shown here.
I have create a WorkerThread class which take care of Threads and GUI current/main thread . i have put my GUI application in construct() method of WorkerThread when an event fire to start XXXServer then all threads are activate and GUI work smoothlly wihout freeze. have a look.
/** * Action Event * * #see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent) */
public void actionPerformed(ActionEvent ae) {
log.info("actionPerformed begin..." + ae.getActionCommand());
try {
if (ae.getActionCommand().equals(btnStart.getText())) {
final int portNumber = 9990;
try {
WorkerThread workerThread = new WorkerThread(){
public Object construct(){
log.info("Initializing the Server GUI...");
// initializing the Server
try {
xxxServer = new XXXServer(portNumber);
xxxServer.start();
btnStart.setEnabled(false);
} catch (IOException e) {
// TODO Auto-generated catch block
log.info("actionPerformed() Start button ERROR IOEXCEPTION..." + e.getMessage());
e.printStackTrace();
}
return null;
}
};workerThread.start();
} catch (Exception e) {
log.info("actionPerformed() Start button ERROR..." + e.getMessage());
e.printStackTrace();
}
} else if (ae.getActionCommand().equals(btnStop.getText())) {
log.info("Exit..." + btnStop.getText());
closeWindow();
}
} catch (Exception e) {
log
.info("Error in ServerGUI actionPerformed==="
+ e.getMessage());
}
}
I have a jbutton which I want, as soon as it's clicked to make an infinite loop of a mouseMove by a robot class. Then, to be stopped when it is clicked again. Problem is in my code when I press it for the first time, it causes the system to freeze and nothing happens when I click it again. I use:
boolean go = false
jb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
go = !go;
if (go)
jb.setText("Stop!");
else
jb.setText("Start!");
try {
Robot robot = new Robot();
while (go) {
robot.mouseMove(500, 500);
robot.delay(1000);
robot.mouseMove(500, 400);
}
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
});
Swing is a single threaded environment. This means that if anything should block this thread, Swing will be unable to respond to new events, including paint requests and it will appear that you UI has been frozen...because it has...
Take a look at Concurrency in Swing
The simplest solution might be to spawn a new thread and run your loop within it...
Start by writing a Runnable that handels the work you want done...
public class MouseRunner implements Runnable {
#Override
public void run() {
try {
Robot robot = new Robot();
while (go) {
robot.mouseMove(500, 500);
robot.delay(1000);
robot.mouseMove(500, 400);
}
} catch (AWTException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
Then when the user first clicks the button, create a Thread and start it...
jb.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
go = !go;
if (go) {
jb.setText("Stop!");
Thread t = new Thread(new MouseRunner());
t.start();
} else {
jb.setText("Start!");
}
}
});
Beware, your go variable is likely going to need to made volatile
In my GUI I have a PDF file creation operation. The operation can take up to 10-15 seconds to complete. When I start the operation, I attach a listener to it. The listener changes the cursor and disables the GUI, until the operation completes.
I would also like to add a progressbar, so the users will have a idea when it is going to complete.
Created a method startProgressBar() and called it from the start of the operation method.
See Below:
private void startSavePdfOperation() {
startProgressBar();
saveOp = new AplotSaveOperation(appReg.getString("aplot.message.SAVETOPDF"), "PDF", session);
saveOp.addOperationListener(new MyOperationListener(this) {
startProgressBar Method - See Below:
public void startProgressBar() {
Shell shell = new Shell(getShell());
shell.setSize(260, 120);
final ProgressBar bar = new ProgressBar(shell, SWT.SMOOTH);
bar.setBounds (20, 20, 200, 20);
shell.open();
final int maximum = bar.getMaximum();
new Thread(new Runnable() {
public void run() {
for (final int[] i = new int[1]; i[0] <= maximum; i[0]++) {
try {Thread.sleep (100);} catch (Throwable th) {}
if (Display.getDefault().isDisposed()) return;
Display.getDefault().asyncExec(new Runnable() {
public void run() {
if (bar.isDisposed ()) return;
bar.setSelection(i[0]);
}
});
}
}
}).start();
The code above created the ProgressBar. The issue is that the operation would end well before the progressbar indicator was close to ending.
Question: Is this because in the method I am creating a new thread and the indicator is updating according to the new thread and not the operation thread?
Question: Is it possible to create a new thread that watches the GUI thread and updates the progressbar accordingly?
Read a article suggesting using ProgressMonitorDialog with IRunnableWithProgress.
Method startProgressBar using ProgressMonitorDialog - see below:
public void startProgressBar() {
ProgressMonitorDialog dialog = new ProgressMonitorDialog(getShell());
try {
dialog.run(true, true, new IRunnableWithProgress(){
public void run(IProgressMonitor monitor) {
monitor.beginTask("Some nice progress message here ...", 100);
** getThread(); **
monitor.done();
}
});
}
catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void getThread() {
new Thread etc.. etc...
}
It seems that it will have the same issues with threading and updating as the code above.
Question: So now I am thinking can I just add or update the ProgressBar to my existing Listener
OperationListener Code - see below:
public abstract class MyOperationListener implements InterfaceAIFOperationListener {
AplotCreatePDFDialog w = null;
public MyOperationListener(AplotCreatePDFDialog win) {
w = win;
}
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
Thanks for any help you can give me with this.
EDIT
Baz, your answer below is exactly what the question asked, so thank you for answering.
But I am starting to think that what I am trying to do is not possible.
When my operation starts, I wanted the progress bar indicator to start and when my operation ended I wanted the indicator be at the end and the monitor would close.
I thought there might bee a way to use my listener to add the progressbar. Something like the following.
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
->monitor.beginTask("Creating PDF File(s)", IProgressMonitor.UNKNOWN);<-
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
->monitor.worked(1);<-
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
->monitor.done();<-
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
But I am starting to see that the ProgressBar has to have some sort of measurement to display the indicator correctly.
I would be happy if the indicator just went back and forth and the monitor would close at the end of the operation.
Why not use ProgressMonitorDialog?
Here is a related answer from me showing a simple example.
This is what it looks like:
If you are not sure about the workload, use this code:
monitor.beginTask("Copying files", IProgressMonitor.UNKNOWN);
It will show the idle bar while running.
I have this ActionListener that gets called in the EDT. My plot() function is computationally heavy, it can easily take five seconds. It made the GUI hang as expected. I added the SwingUtilities.invokeLater code and it still hangs. Shouldn't the GUI be responsive now that I am spawning a separate thread for my heave computation?
final ActionListener applyListener = new ActionListener()
{
#CommitingFunction
public void actionPerformed(ActionEvent arg0)
{
/*Don't do plotting in the EDT :)*/
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
plot();
}
});
}
};
Not at all. InvokeLater is not producing a new thread. invokeLater exists to tell Swing explicitly "use the Event Dispatching Thread for this, but not right now". invoke and invokeLater exist to let you do operations that are only safe for the Event Dispatching Thread from other threads- not by doing them on those threads, but by telling the EDT to do them.
Your ActionListener will run very quickly, throwing the Runnable on Swing's event dispatching queue. Then when it gets that far, it will take five seconds to run the plot().
The only workaround is to refactor plot(). Use a SwingWorker (or similar multithreading strategy, but SwingWorker is probably the best for this) to actually move the logic of plot() onto a different thread. That thread cannot safely draw anything because it is not the Swing Event Dispatching Thread, so all of its draw operations need to be performed via invokeLater(). For efficiency reasons, you should try to do all of the drawing operations at once, on one invokeLater(), using results stored from your calculation.
You're doing the opposite of what you think you are. Instead of running your computation thread outside of the EDT, you're explicitly calling it within it!
SwingUtilities.invokeLater() queues up the runnable for invocation at a later time, in the EDT! You want to use SwingWorker instead.
invokeLater add a task to the GUIs work queue. It will be invoked after all other tasks have been performed, however it still uses the GUI thread.
I suggest you look at using an ExecutorService.
As #Adam suggests, any actual drawing it does needs to be done via invokeLater.
You don't show what is inside the plot() function, but you should not put any painting in there. Compute whatever you want in the new thread, and do the painting in the EDT. To do this, it is better to use SwingWorker
Here is what I did for my company's app, this is some pseudo code because of legal reasons, but the jist of it is that if the screen is unresponsive, it will reboot the GUI. Whenever you use SwingUtilities to kick off the EDT, in that same init block, create two watcher threads. One thread will simply perform an action on the EDT thread using Swing utilities. Another thread will monitor the first thread to see if feels the first thread is responsive. The first thread will only acknowledge responsiveness if it can perform a very simple command.
set isEDTCheck to true when running in normal fashion, false in debug mode (otherwise you'll constantly get rebooted.
if (isEDTCheck) {
new Thread("EDTHeartbeat") {
#Override
public void run() {
Runnable thisThingYouDo = new Runnable() {
public void run() {
int x = 0;
}
};
while (true) {
// first thread says we are waiting, aka bad state
edtwait=true;
try {
javax.swing.SwingUtilities.invokeAndWait(thisThingYouDo);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// first thread says we are not waiting, good state
edtwait=false;
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}.start();
new Thread("EDTValidator") {
#Override
public void run() {
while (true) {
// is first thread in bad state?
if (edtwait) {
try {
Thread.sleep(3000);
// after 3 seconds are we still in bad state? if so, get rid of initial frame, pop up a dialog box in AWT that does no commands
if (edtwait) {
mainFrame.setVisible(false);
new Dialog();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}.start();
}
public class Dialog extends Frame {
private static final int WIDTH = 400;
private static final int HEIGHT = 300;
Frame f = null;
public Dialog() {
f = this;
hasSomethingBeenEntered=false;
this.setTitle("APP PROBLEM DETECTED");
this.setSize(WIDTH, HEIGHT);
this.setLocation((int)Toolkit.getDefaultToolkit().getScreenSize().getWidth() - myapp.width, 0);
Panel p1 = new Panel() {
#Override
public void paint(final Graphics g) {
int left = Dialog.WIDTH/2 - 45; // don't use WIDTH shadowed by Panel class
int top = Dialog.HEIGHT/2 - 20; // same as above
g.drawString("APP HAS DETECTED A PROBLEM", left, top);
}
};
this.add("Center", p1);
this.setAlwaysOnTop(true);
TextArea tb = new TextArea("APP HAS DETECTED A MAJOR PROBLEM\nIT WILL NOW RESTART IN 5 SECONDS");
this.add(tb);
this.setVisible(true);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
restartApp();
}
private void restartApp() {
Runtime.getRuntime().exec("cmd /c start cmd.exe /K \"cd C:\\Progra~1\\Common~1 && C:\\Progra~1\\Common~1\\MyAppDir\\myjavaapp.jar\"");
System.exit(0);
}