How to set a Running Time on Label(SWT) along with Date name

Question

I want to display the date and its name along with running time on Swt label. Here is my code:-

    Label DateLbl = new Label(shell, SWT.NONE);   
    DateLbl.setBounds(0,0,100,50);

    DateFormat dateFormat1 = new SimpleDateFormat("dd/MM/yyyy  HH:mm:ss");
    Calendar cal1 = Calendar.getInstance();


    DateFormatSymbols dfs1 = new DateFormatSymbols();
    String weekdays1[] = dfs1.getWeekdays();

    int day1 = cal1.get(Calendar.DAY_OF_WEEK);

    String nameOfDay1 = weekdays1[day1];


    DateLbl.setText(" "+dateFormat1.format(cal1.getTime()) +             " \n" +"        "+nameOfDay1);

It displays the time, date and date name but i want running second, minute and hour ( a complete virtual clock on Label).

here is o/p for above code - 26/03/2014 12:57:01 wednesday

Time gets updated each time when i launch my application.

Could anyone suggest something to make second, minute, hour run on SWT label.

Answer 1

You can use the java.util.Timer class to run code periodically:

Timer timer = new Timer("clock timer", true);

timer.schedule(new UpdateTimerTask(), 1000l, 1000l);  // Run once a second


private class UpdateTimerTask extends TimerTask
{
  @Override
  public void run()
  {
    // Timer task runs in a background thread, 
    // so use Display.asyncExec to run SWT code in UI thread

    Display.getDefault().asyncExec(new Runnable() 
     {
       @Override
       public void run()
       {
         // TODO update the label
       }
     });  
  }
}

Answer 2

Your question is not clear? Do you want a clock updating with the current time second-by-second?

If so, you need to spawn a thread to sleep and wake every second. The thread then updates the user interface in whatever thread-safe manner is appropriate to swt, and returns to sleep.

For the sleeping thread, you can use either a Timer or a ScheduledExecutorService. Each has its merits.

To update the user-interface… I don't know swt, but expect you need to find the equivalent of SwingWorker used in Swing.

Answer 3

SWT has default native timer support. use below method

org.eclipse.swt.widgets.Display.timerExec(int, Runnable)

please read documentation for more information.