Tab bar in blackberry without ToolBarManager

This is a sample code that how to create Tabs in blackberry.
I had total 3 screens after statUp(which extends UiApplication) class

1. LoadingScreen.java

   public class LoadingScreen extends MainScreen
   {   
   int current_index=0;
   BottomPanel bottomPanel;
   public LoadingScreen(int current_index)
   {   
      this.current_index=current_index;
      bottomPanel=new BottomPanel(current_index);
   }
   
   public  void createGUI() 
   {       
   setTitle("Loading Screen");
   
   VerticalFieldManager vertical=new VerticalFieldManager(USE_ALL_WIDTH)
   {
       protected void sublayout(int maxWidth, int maxHeight) 
       {               
           super.sublayout(Display.getWidth(), 150);
           setExtent(Display.getWidth(), 150);
       }
   };
   vertical.setBackground(BackgroundFactory.createSolidBackground(Color.GREEN));
   ButtonField button=new ButtonField("Click");
   vertical.add(button);       
   add(vertical);
   
   setStatus(bottomPanel);     
   }
   }
   

2. BottomPanel.java

   public class BottomPanel extends VerticalFieldManager implements FieldChangeListener 
   {
      Bitmap news_bit=Bitmap.getBitmapResource("news.png");//these images are cutting according to device requirement;
      Bitmap news_bit_hover=Bitmap.getBitmapResource("news_h.png");
      Bitmap settings_bit=Bitmap.getBitmapResource("settings.png");
      Bitmap settings_bit_hover=Bitmap.getBitmapResource("settings_h.png");
      Bitmap about_bit=Bitmap.getBitmapResource("about.png");
      Bitmap about_bit_hover=Bitmap.getBitmapResource("about_h.png");
      PictureBackgroundButtonField news_pic,settings_pic,about_pic;
      HorizontalFieldManager hr;
      int current_index=0;
      public BottomPanel(int current_index)
      {        
      super(FOCUSABLE);
      this.current_index=current_index;
     VerticalFieldManager ver=new VerticalFieldManager(USE_ALL_WIDTH|USE_ALL_HEIGHT)
     {         
       protected void sublayout(int width, int height) 
       {
           super.sublayout(width, news_bit.getHeight());
           setExtent(width, news_bit.getHeight());
       }
   };
   hr=new HorizontalFieldManager(FIELD_HCENTER);
   if(current_index==1)
   {
       news_pic=new PictureBackgroundButtonField(news_bit.getWidth(),news_bit.getHeight(), Field.NON_FOCUSABLE|Field.FIELD_VCENTER, news_bit_hover, news_bit_hover);
   }
   else
   {
       news_pic=new PictureBackgroundButtonField(news_bit.getWidth(),news_bit.getHeight(), Field.FOCUSABLE|Field.FIELD_VCENTER, news_bit, news_bit_hover);
   }
   news_pic.setChangeListener(this);
   hr.add(news_pic);
   
   if(current_index==2)
   {
       settings_pic=new PictureBackgroundButtonField(settings_bit.getWidth(),settings_bit.getHeight(), Field.NON_FOCUSABLE|Field.FIELD_VCENTER, settings_bit_hover, settings_bit_hover);
   }
   else
   {
       settings_pic=new PictureBackgroundButtonField(settings_bit.getWidth(),settings_bit.getHeight(), Field.FOCUSABLE|Field.FIELD_VCENTER, settings_bit, settings_bit_hover);
   }
   settings_pic.setChangeListener(this);
   hr.add(settings_pic);
   
   if(current_index==3)
   {
       about_pic=new PictureBackgroundButtonField(about_bit.getWidth(),about_bit.getHeight(),Field.NON_FOCUSABLE|Field.FIELD_VCENTER, about_bit_hover, about_bit_hover);
   }
   else
   {
       about_pic=new PictureBackgroundButtonField(about_bit.getWidth(),about_bit.getHeight(), Field.FOCUSABLE|Field.FIELD_VCENTER, about_bit, about_bit_hover);
   }
   about_pic.setChangeListener(this);
   hr.add(about_pic);
   
   ver.add(hr);
   add(ver);
   }
   
   public void fieldChanged(Field field, int context) 
   {           
   if(field==news_pic)
   {               
       LoadingScreen loadingScreen=new LoadingScreen(1);
       UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
       UiApplication.getUiApplication().pushScreen(loadingScreen);
       loadingScreen.createGUI();
   }
   else if(field==settings_pic)
   {
       LoadingScreen loadingScreen=new LoadingScreen(2);
       UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
       UiApplication.getUiApplication().pushScreen(loadingScreen);
       loadingScreen.createGUI();
   }
   else if(field==about_pic)
   {
       LoadingScreen loadingScreen=new LoadingScreen(3);
       UiApplication.getUiApplication().popScreen(UiApplication.getUiApplication().getActiveScreen());
       UiApplication.getUiApplication().pushScreen(loadingScreen);
       loadingScreen.createGUI();
   }       
   }
   }   
   

3. PictureBackgroundButtonField.java

   public class PictureBackgroundButtonField extends Field 
   {       
       private String _label;
       private int _labelHeight;
       private int _labelWidth;
       private Font _font;
   
       private Bitmap _currentPicture;
       private Bitmap _onPicture ;
       private Bitmap _offPicture ;
       public PictureBackgroundButtonField(int width,int height, long style, Bitmap picture, Bitmap selectedPic) 
       {
           super(style);
   
          _font = getFont();
          _label = "";
         _labelHeight = height;
         _labelWidth = width;
         _currentPicture = picture;
         _onPicture = selectedPic;
         _offPicture = picture;        
      }
      public int getPreferredHeight() 
      {
          return _labelHeight;
      }
      public int getPreferredWidth() 
      {
          return _labelWidth;
      }
      protected void onFocus(int direction) 
      {
          _currentPicture = _onPicture;
          invalidate();
      }
      protected void onUnfocus() 
      {
           _currentPicture = _offPicture;
           invalidate();
      }
      protected void drawFocus(Graphics graphics, boolean on) 
      {
           // Do nothing
      }
      protected void layout(int width, int height) 
      {
          setExtent( getPreferredWidth(), getPreferredHeight());
      }
      protected void paint(Graphics graphics) 
      {            
              graphics.drawBitmap(0, 0, getPreferredWidth(), getPreferredHeight(), _currentPicture, 0, 0);     
              graphics.setFont(_font);
              graphics.drawText(_label, 4, 2, 
       (int)( getStyle() & DrawStyle.ELLIPSIS | DrawStyle.HALIGN_MASK ),
       getWidth() - 6 );
     }
     protected boolean navigationClick(int status, int time) 
     {
            fieldChangeNotify(1);
            return true;
     }    
   }
   

Try this code and see the difference;