Add field manager to application Main screen in BlackBerry

Question

I am working with a BlackBerry application for OS 5.0 and later. The application has one screen which displays at the top of screen a Next and a Previous button. and list field also display in this screen at bottom of these both button

When i click on NEXT Button and Previous Button my List will be updated display data..

When i click on NEXT/PREVIOUS Button i have to display small VerticalfieldManager at the center of the screen with Label "Please wait ..." so after design this screen how can we add more field manager in over the another manager ?

Is there any way to display that Field at the application MainScreen like iPhone AppDelegate screen?

btnState.setChangeListener(new FieldChangeListener() {

        public void fieldChanged(Field field, int context) 
        {   vfm_Middle.add(lblPleasewait);
            popup = new PopupScreen(manager);
            Thread thread = new Thread()
            {
                public void run() 
                {
                    try
                    {
                        Updatelistfield();
                        stop();
                    }
                    catch (InterruptedException e) 
                    {
                        e.printStackTrace();
                    }
                    super.run();
                }

                public synchronized void stop() 
                {
                    // TODO Auto-generated method stub
                    UiApplication.getUiApplication().invokeLater(new Runnable() {

                        public void run() 
                        {
                            // TODO Auto-generated method stub
                            //popup.delete(vfm_Main);
                            //popup.deleteAll();
                            //vfm_Main.delete(lblPleasewait);
                            //lblPleasewait.setText(null);

                        }
                    });
                }
            };

            thread.start();

        }
    });

Answer 1

The proper way of doing that is with a blocking dialog. In BB API this can be done as follows:

VerticalFieldManager manager = new VerticalFieldManager();
manager.add(new LabelField("Please Wait..."));
Screen popup = new PopupScreen(manager);
//Show the pop-up the same way you push a regular screen

This has the advantage of blocking the GUI: if the user pushes the menu or esc key it doesn't have any effect.

If you want to do it in your screen without dialogs, then you can add an empty VerticalFieldManager which you can fill with a label when the message has to be shown. This way, instead of updating the entire screen, only the Manager is refreshed. But then you should write the logic to not letting the user push any button or menu key (or ignoring key press).