import net.rim.blackberry.api.bbm.platform.*;
import net.rim.device.api.ui.component.*;
public class MyBBMContactListScreen implements PresenceListener
{
    public MyClass(BBMPlatformContext platformContext) 
    {
       platformContext.getContactListService().setPresenceListener(this);
    }
    public void presenceUpdated(BBMPlatformContact contact, int eventType)
    {
        final String str = "[" + getEventName(eventType) + "] was changed by " + contact.getDisplayName();
        Dialog.inform(str);
    }
    private String getEventName(int eventType)
    {
        String eventName;
        switch(eventType)
        {
            case PresenceListener.EVENT_TYPE_DISPLAY_PICTURE:
                eventName = "Display picture";
                break;
            case PresenceListener.EVENT_TYPE_DISPLAY_NAME:
                eventName = "Display name";
                break;
            case PresenceListener.EVENT_TYPE_PERSONAL_MESSAGE:
                eventName = "Personal Message";
                break;
            case PresenceListener.EVENT_TYPE_STATUS:
                eventName = "Status";
                break;
            default:
                eventName = "Default";
        }
    }
}