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need help with swing and multithreading (gui lockup)

Posted on 2003-10-31
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Last Modified: 2011-09-20
I have a multithreaded application and am using swing as my interface.  My threads communicate with each other through queues that are class objects of the base class the threads are derived from.

I want to click a menu item to send a message to one of the threads and wait for a response in the background and then reenable the menu item it has been recieved. I've read the sun doc's and thought i could use invokelater ()., but my gui locks up. cCan anyone help. herses the code

// heres the event handler for menu item
public void actionPerformed(ActionEvent e)
  {

   adaptee.OffHook_actionPerformed(e);
   // disable menu item
   adaptee.OffHook.setEnabled(false);

 
   Runnable doWorkRunnable = new Runnable()
   {
     public void run()
       {
       ProcessConsleMsg ();
       }
    };

  // I thought this would run in background thread
   SwingUtilities.invokeLater (doWorkRunnable);
  }


// sends a message to control queue and waits for response
// console queue
  public void ProcessConsleMsg ()
  {
   Msg zMsg;

   zMsg = new Msg ();
   zMsg.SetMsgType(OFF_HOOK);

   // send message to crontrol task
   ConsleTsk.SendCtrlMsg(zMsg);

    // wait for response to return in consle queue
    // on purpose I'm not send back a response, locking up gui
   // wy doesn't this porocess run in background?
    while (ConsleTsk.ConsleQue.GetMsg()   == null);

    adaptee.OffHook.setEnabled(true);

   }

}
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Question by:BlackRussian
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4 Comments
 
LVL 92

Expert Comment

by:objects
ID: 9661344
> // I thought this would run in background thread
>  SwingUtilities.invokeLater (doWorkRunnable);

No that says to run it in the swing thread.

You need to wait in a new Thread, and once done then call invokeLater from tyhat thread to notify your gui.
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Author Comment

by:BlackRussian
ID: 9661646
Can you point me to some example code. I was using the bingo example in sun docs.
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Accepted Solution

by:
objects earned 250 total points
ID: 9661663
something like:

public void actionPerformed(ActionEvent e)
  {

   adaptee.OffHook_actionPerformed(e);
   // disable menu item
   adaptee.OffHook.setEnabled(false);

 
   Runnable doWorkRunnable = new Runnable()
   {
     public void run()
       {
       ProcessConsleMsg ();
       }
    };

   new Thread(doWorkRunnable).start();
  }


// sends a message to control queue and waits for response
// console queue
  public void ProcessConsleMsg ()
  {
   Msg zMsg;

   zMsg = new Msg ();
   zMsg.SetMsgType(OFF_HOOK);

   // send message to crontrol task
   ConsleTsk.SendCtrlMsg(zMsg);

    // wait for response to return in consle queue
    // on purpose I'm not send back a response, locking up gui
   // wy doesn't this porocess run in background?
    while (ConsleTsk.ConsleQue.GetMsg()   == null);

    EventQueue.invokeLater(new Runnable()
    {  public void run() { adaptee.OffHook.setEnabled(true); }});

   }

}
0
 
LVL 92

Expert Comment

by:objects
ID: 9661803
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