Re: sleep causing the app to hang

From:

jny0 <jny0@hotmail.com>

Newsgroups:

comp.lang.java.gui

Date:

Thu, 23 Jul 2009 01:52:18 -0700 (PDT)

Message-ID:

<646e8b35-5a40-4971-be3a-3337e81cc258@24g2000yqm.googlegroups.com>

On Jul 21, 2:48 pm, "John B. Matthews" <nos...@nospam.invalid> wrote:

In article <H42dnc3v-raIBvjXnZ2dnUVZ8vmdn...@novis.pt>,
Sabine Dinis Blochberger <no.s...@here.invalid> wrote:

jny0 wrote:

I'm trying to use sleep( 1000 ) to time some GUI outputs:

jny0: You can self-time the GUI operation, e.g. paintTime:

<http://sites.google.com/site/drjohnbmatthews/kineticmodel/code
#DisplayPanel>

You can then update the display periodically in a javax.swing.Timer's
actionPerformed() method:

<http://sites.google.com/site/drjohnbmatthews/kineticmodel/code
#ControlPanel>

for (int iDepthCtr = 1 ; iDepthCtr <= 10 ; iDepthCtr++)
    {
        try
        {
            t1.currentThread().sleep( 1000 );
        }
        catch (InterruptedException e){ }
        jLabel1.setText(String.valueOf(iDepthCtr));
    }

The idea is that every second, the label will increment (1, 2, 3 ...
10). But instead, the system hangs for 10 seconds, than displays 1=

Any ideas?

Somehow you're blocking the event dispatch thread (EDT), it will only
update when the for loop is done. Read up on concurrency in Swing:
<http://java.sun.com/docs/books/tutorial/uiswing/concurrency/index.html=

And if you want to update the GUI from outside the EDT use
invokeLater:
<http://java.sun.com/javase/6/docs/api/javax/swing/SwingUtilities.html

#invokeLater(java.lang.Runnable)>

jny0: In addition to this excellent advice, if your goal is to visually
monitor the progress of a separate process, consider using SwingWorker:

<http://www.j2ee.me/javase/6/docs/api/javax/swing/SwingWorker.html>

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>- Hide quoted text -

- Show quoted text -

Thank you chaps.