private int PicPosition; 
private Handler handler = new Handler(); 

 

private Runnable runnable = new Runnable() { 
    public void run() { 
        myslideshow(); 
        handler.postDelayed(this, 1000);. 
    } 
}; 
 
    private void myslideshow() 
    {                      PicPosition = gallery.getSelectedItemPosition() +1;              
                    if (PicPosition >=  Pictures.size())             
                    PicPosition =  gallery.getSelectedItemPosition(); //stop  
                                    else 
                    gallery.setSelection(PicPosition);//move to the next gallery element. 
    }