waiting or loading screen in java

[jamil lusa]

hi all,

i am running a program that execute quite a numbers of loop. the program will not be responsive when running with those loop. i want to create a form that stay on top of the program and notify the user about the progress of execution.

How can i do that? i try to google the example but no luck. and the clue point me to use threading which i am not really good at (know a bit).

can anyone show me a very simple coding regarding to this problem? just a simple waiting form stay on the main form when the main program is executing a huge loop. after loop finish, the waiting screen gone.


Thanks your all help in advanced!

[John Jai]

If the UI is Swing then you can use the wait cursor.

[jamil lusa]

i need a form-like waiting screen instead of waiting cursor because it can provide more information (display on the waiting form) for the user.

[Tim Moores]

What prevents you from putting a dialog in front of the main window whenever you need to?

[Campbell Ritchie]

I think this thread would sit better on our GUIs forum, so shall move it.
Please avoid coloured text; some people find it very difficult to read.

[Darryl Burke]

Have you considered using a ProgressMonitor? you'll find a link to a tutorial from the API of the class.

[jamil lusa]

Thank Darryl, ProgressMonitor is good to use.

-----------------------

hi all, but i am still curious how to create a customized loading form (something like showing 'please wait...') by myself using threading because it is a good chance to learn that.

anyone is kind enough to show me? thanks.

[Michael Dunn]

here's a quick (rough) example

click the button, the dialog will show, you can move the dialog, but not close it or access the frame
when the task is over, the dialog disappears, and you can again access the frame

(this is not a good example of doing what you want, ProgressMonitor is the better/best way)

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Testing
{
  public void buildGUI()
  {
    JPanel p = new JPanel(new BorderLayout());
    final JButton btn = new JButton("Do Some Long Task");
    p.add(btn,BorderLayout.SOUTH);
    final JFrame f = new JFrame();
    f.getContentPane().add(p);
    f.setSize(400,300);
    f.setLocationRelativeTo(null);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
    btn.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent ae){
        final JDialog d = new JDialog();
        JPanel p1 = new JPanel(new GridBagLayout());
        p1.add(new JLabel("Please Wait..."),new GridBagConstraints());
        d.getContentPane().add(p1);
        d.setSize(100,100);
        d.setLocationRelativeTo(f);
        d.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
        d.setModal(true);

        Thread t = new Thread(){
          public void run(){
            for (int x = 0; x <= 100; x+=10)
            {
              final int selection = x;
              SwingUtilities.invokeLater(new Runnable(){//do swing work on EDT
                public void run(){
                  btn.setText("long task up to "+selection+"%");
                }
              });
              try
              {
                Thread.sleep(1000);
              }
              catch (InterruptedException e) {e.printStackTrace();}
            }
            SwingUtilities.invokeLater(new Runnable(){//do swing work on EDT
              public void run(){
                d.dispose();
                btn.setText("Do Some Long Task");
              }
            });
          }
        };
        t.start();
        d.setVisible(true);
      }
    });
  }
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new Runnable(){
      public void run(){
        new Testing().buildGUI();
      }
    });
  }
}

[Rob Spoor]

Why not use a SwingWorker in that example?

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Testing
{
  public void buildGUI()
  {
    JPanel p = new JPanel(new BorderLayout());
    final JButton btn = new JButton("Do Some Long Task");
    p.add(btn,BorderLayout.SOUTH);
    final JFrame f = new JFrame();
    f.getContentPane().add(p);
    f.setSize(400,300);
    f.setLocationRelativeTo(null);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
    btn.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent ae){
        final JDialog d = new JDialog();
        JPanel p1 = new JPanel(new GridBagLayout());
        p1.add(new JLabel("Please Wait..."),new GridBagConstraints());
        d.getContentPane().add(p1);
        d.setSize(100,100);
        d.setLocationRelativeTo(f);
        d.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
        d.setModal(true);

        SwingWorker<?,?> worker = new SwingWorker<Void,Integer>(){
          protected Void doInBackground() throws InterruptedException{
            for (int x = 0; x <= 100; x+=10)
            {
              publish(x);
              Thread.sleep(1000);
            }
            return null;
          }

          protected void process(List<Integer> chunks){
            int selection = chunks.get(chunks.size() - 1);
            btn.setText("long task up to "+selection+"%");
          }

          protected void done(){
            d.dispose();
            btn.setText("Do Some Long Task");
          }
        };
        worker.execute();
        d.setVisible(true);
      }
    });
  }
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new Runnable(){
      public void run(){
        new Testing().buildGUI();
      }
    });
  }
}