JProgressBar not displaying or updating.

Hi,

I want to display the progress of a task to the user. The task happen in
a non gui class of my application which simply update a currentProgress
attribute which I want the Progress Bar class to check every second and
update the bar.

I have the issue that the dialog containing the JProgressBar displays
but none of the components are displayed until the task has completed.
Debugging the code I discovered that the timer event which should fire
every second also does not until the task is over.

I am sure I am doing something fundamentally wrong but have searched
newsgroups and the net with no luck. I have also looked at and
implemented the Java Sun Progress Bar examples.

Below is the code I have on my main code line:

Code>>>>>>>>>>>>>>>>>>>>>>>

//First we create the ProcessBarDialog but do nothing with it at this stage.

final ProgressBarDialog pbd = new ProgressBarDialog("Paste", false);

SwingWorker bar = new SwingWorker(){
public Object construct() {
pbd.setProgressable(task);
//Display and start the ProgressBarDialog
pbd.startProgress();
return pbd;
}
};
bar.start();


//Actual Task Runs on main line so we don't return until it is complete
java.util.List itemsToRemove = new ArrayList();
for (int i=0; i < pastedObjects.size(); i++) {
if (pastedObjects.get(i) instanceof AdvancedGraph) {
itemsToRemove.add(pastedObjects.get(i));
}
}
pastedObjects.removeAll(itemsToRemove);
.. . .
.. . .
.. . .
CONT...

END CODE>>>>>>>>>>>>>>>>>>>

The ProgressBarDialog class is simple a dialog class which displays a
JLabel, JProgressBar and JButton.

pbd.setProgressable(task);

This stored a reference in the Dialog class so it can get the current
progress of the task every time the Timer event fires.

Below is the contents of the pbd.startProgress(); method:

CODE>>>>>>>>>>>>>>>>>>>>

timer = new Timer(ONE_SECOND, new ActionListener() {
public void actionPerformed(ActionEvent evt) {

//Until the task is initalised we can not do anything
if(task != null){
//Get the current progress.
int currentProgress = task.getCurrentProgress();
progressBar.setValue(currentProgress);

if (currentProgress > 0 && progressBar.isIndeterminate()) {
progressBar.setIndeterminate(false);
progressBar.setString(null); //display % string
}

if (task.isDone() ) {//|| cancelled
timer.stop();
progressBar.setValue(progressBar.getMinimum());
progressBar.setString(""); //hide % string
parentFrame.dispose();
//reset the task ready for use again if required.
task.reset();
}
}
}
});

//Display the Progress Bar dialog
displayProgress();

//Set the mode to Indeterminate to start with.
progressBar.setIndeterminate(true);

//Start the timer.
timer.start();

END CODE>>>>>>>>>>>>>>>>>>>>>>>>

The displayProgress() method creates a JDialog and puts the components
in the Dialog.

I have tried invokeLater and invokeAndWait in a number of places and the
whole thing it really starting to annoy me.

Thanks for anybodys help.

James

On Tue, 02 Aug 2005 14:01:44 GMT, James Gralton wrote:

> I have tried invokeLater and invokeAndWait in a number of places and the
> whole thing it really starting to annoy me.

Perhaps you should try it in your SSCCE.
(I doubt anybody will wade through that code
snippet mess you posted.)

Of course, you had a look through the GUI FAQ,
and ruled out blocking the EDT?

--
Andrew Thompson
physci.org 1point1c.org javasaver.com lensescapes.com athompson.info
See You On Some Other Channel

Thanks,

I thought it better to format my question the way I did rather than dump all my code.

I tried to get all the information people would need to help in in the best way possible and don't
believe if you read it properly it is a mess.



Andrew Thompson wrote:
> On Tue, 02 Aug 2005 14:01:44 GMT, James Gralton wrote:
>
>
>>I have tried invokeLater and invokeAndWait in a number of places and the
>>whole thing it really starting to annoy me.
>
>
> Perhaps you should try it in your SSCCE.
> (I doubt anybody will wade through that code
> snippet mess you posted.)
>
> Of course, you had a look through the GUI FAQ,
> and ruled out blocking the EDT?
>

James Gralton wrote:
> I tried to get all the information people would need to help in in the
> best way possible and don't believe if you read it properly it is a mess.

In case you are interested in a second opinion. Your random selection of
incoherent fragments is a mess. I started to look at the code,
recognized that it was just fragments, in no way indicating the real
flow of control and events, and that I would probably have to make a
drawing to piece it all together. At that point I decided to skip it.

No one here has an obligation to help you. If you want help it would be
clever to present the problem in a way that is easy to comprehend. If
you can't be bothered to do that, why should we bother to spend out time
on your problem?

/Thomas

--
The comp.lang.java.gui FAQ:
ftp://ftp.cs.uu.nl/pub/NEWS.ANSWERS/...g/java/gui/faq
http://www.uni-giessen.de/faq/archiv....java.gui.faq/

Sorry Thomas/Andrew,

I thought I had made an ok post but obviously in my frustration with this issue rushed it a but. I
do really appreciate yours and everyones help.

I have constructed a small example which compiles and runs to demonstrate my issue. It contains 4
classes to demonstrate the set up I am trying to achieve. One of the classes is the SwingWorker
class from Sun's Java site.

The src is at www.gralton.com/post/src
and the classes if you needs them are at www.gralton.com/post/classes

The main class is Simple.

Upon running the app please press the Go Task button. The ProgressBarDialog displays with no
JProgressBar.

Thanks for your help here.

James

Thomas Weidenfeller wrote:
> James Gralton wrote:
>
>> I tried to get all the information people would need to help in in the
>> best way possible and don't believe if you read it properly it is a mess.
>
>
> In case you are interested in a second opinion. Your random selection of
> incoherent fragments is a mess. I started to look at the code,
> recognized that it was just fragments, in no way indicating the real
> flow of control and events, and that I would probably have to make a
> drawing to piece it all together. At that point I decided to skip it.
>
> No one here has an obligation to help you. If you want help it would be
> clever to present the problem in a way that is easy to comprehend. If
> you can't be bothered to do that, why should we bother to spend out time
> on your problem?
>
> /Thomas
>

James Gralton wrote:
>
> I am sure I am doing something fundamentally wrong but have searched
> newsgroups and the net with no luck. I have also looked at and
> implemented the Java Sun Progress Bar examples.

In addition to what other people have said, if you think the problem is
in a certain area but can't find it there, perhaps it is elsewhere. To
do any effective diagnosis we need a small, self-contained example that
illustrates the problem without extraneous details.

If you do find the problem, do tell us what it was. It may help someone
searching through the archives for a similar problem, and makes us more
aware of the sort of problems that other people have.


Anyway here are some things you might want to consider.

> final ProgressBarDialog pbd = new ProgressBarDialog("Paste", false);

Made up acronyms don't help readablitiy.

> SwingWorker bar = new SwingWorker(){
> public Object construct() {

What does this method do? The latest SwingWorker documentation is here

https://swingworker.dev.java.net/jav...ingWorker.html

The method isn't present. I know everyone likes to support out of date
machines, but it's well worth upgrading to the current JRE/JDK and
slapping on an @Overrides.

A liberal sprinkiling of assert [!]EventQueue.isDispatchThread(); would
help to document in which thread blocks should be run (don't forget -ea).

Tom Hawtin
--
Unemployed English Java programmer
http://jroller.com/page/tackline/

Unfortunatly I can get the example to work in smaller programs it is when I try to extend it to my
application that I am have the issue below. I know 4 classes is quite a lot ofr a small example but
each of them is doing very little.

If I find a solution I will reply to the post for sure.

Thanks for your advice I will look at the new SwingWorker documentation and see if it helps me at all.

James

Thomas Hawtin wrote:
> James Gralton wrote:
>
>>
>> I am sure I am doing something fundamentally wrong but have searched
>> newsgroups and the net with no luck. I have also looked at and
>> implemented the Java Sun Progress Bar examples.
>
>
> In addition to what other people have said, if you think the problem is
> in a certain area but can't find it there, perhaps it is elsewhere. To
> do any effective diagnosis we need a small, self-contained example that
> illustrates the problem without extraneous details.
>
> If you do find the problem, do tell us what it was. It may help someone
> searching through the archives for a similar problem, and makes us more
> aware of the sort of problems that other people have.
>
>
> Anyway here are some things you might want to consider.
>
>> final ProgressBarDialog pbd = new ProgressBarDialog("Paste", false);
>
>
> Made up acronyms don't help readablitiy.
>
>> SwingWorker bar = new SwingWorker(){
>> public Object construct() {
>
>
> What does this method do? The latest SwingWorker documentation is here
>
> https://swingworker.dev.java.net/jav...ingWorker.html
>
>
> The method isn't present. I know everyone likes to support out of date
> machines, but it's well worth upgrading to the current JRE/JDK and
> slapping on an @Overrides.
>
> A liberal sprinkiling of assert [!]EventQueue.isDispatchThread(); would
> help to document in which thread blocks should be run (don't forget -ea).
>
> Tom Hawtin

James Gralton wrote:
>
> I have constructed a small example which compiles and runs to
> demonstrate my issue. It contains 4 classes to demonstrate the set up I
> am trying to achieve. One of the classes is the SwingWorker class from
> Sun's Java site.

It's still far from minimal, but no matter.

Just looking at the code without running it.

public static void main(String[] args) {
try{
UIManager.setLookAndFeel(UIManager.getSystemLookAn dFeelClassName());
Simple s = new Simple();
s.setVisible(true);
}
catch(Exception e){
e.printStackTrace();
}
}

This needs to be done in the EDT. Wrap it in:

EventQueue.invokeLater(new Runnable() { public void run() { }});

From goTask in the EDT:

SwingWorker bar = new SwingWorker(){
public Object construct() {
pbd.setTask(t);
//Display and start the ProgressBarDialog
pbd.startProgress();
return pbd;
}
};
bar.start();

t.doJob();

And doJob has a sleeping while loop. That loop is running in the EDT.
Therefore no events can run and the GUI is locked up.

If we look in ProgressBarDialog.startProgress it is doing stuff to GUI
components from outside of the EDT. That should not be done.

I suggest plenty of

assert EventQueue.isDispatchThread();

and

assert !EventQueue.isDispatchThread();

(and -ea).

Actually I suggest wrapping
EventQueue.isDispatchThread/invokeLater/invokeAndWait in an interface so
that you can do unit testing.

Tom Hawtin
--
Unemployed English Java programmer
http://jroller.com/page/tackline/